ITRM980381A1 - LINEAR MOTION GUIDE EQUIPMENT - Google Patents

Description

DESCRIPTION of the industrial invention entitled: LINEAR MOTION GUIDING EQUIPMENT "

DESCRIPTION

FOUNDATION OF THE INVENTION

Field of the invention

The present invention relates to a linear motion guide apparatus in which a resin-formed passage forming member is incorporated in a movable member body.

Description of the related technique

The Applicant has already proposed a technical idea whereby, in a movable block of a linear motion guide apparatus, a pair of portions that form passage of balls extending along the opposite longitudinal sides of a running groove of loaded balls, a ball return passage forming portion and a pair of change direction passage inner guide forming portions were integrally formed of resin in a movable block body (reference to Japanese Patent Provisional Publication No. H7- 317.762).

More specifically, when resin molding is performed, the movable block body is inserted into a mold, and the ball passage forming portions, the change direction passage inner guide forming portions, or the bead forming portion. return passage of balls are formed integrally with the block body.

In the conventional movable block obtained by integral forming, the block body is inserted into the mold as mentioned above. When the block body has a large size, it is required to use a large scale mold. It is not easy to prepare such a large-scale mold, and there is an actual size limitation. The pass-forming portions of balls located on opposite longitudinal sides of the ball run groove extending along the longitudinal direction of the block body are thin and long with the result that the molten resin may not reach every part of the space to form portions of spherical passage formation during the resin formation treatment.

An increase in the number of casting attachments formed on the mold can solve the aforementioned problem of poor casting of the molten resin. However, when the block body is inserted into the mold, the block body can deteriorate the flow of the molten resin.

When the movable block has a pair of wing portions, which are opposite left and right side portions of the guide rail so that the guide rail is held between the wing portions, and there are four trains of balls between the left and right side portions of the guide rail and the left and right side wing portions of the motion block and more specifically, the upper and lower trains of balls are disposed in each of a recess between the right side portion of the guide rail and the corresponding right side wing portion of the movement block, and another gap between the left side portion of the guide rail and the corresponding left side wing portion of the movement block. movement, the block body inserted into the mold can deteriorate the flow of the molten resin in the width direction of the movement block.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide linear motion guiding apparatus in which a resin-formed body for forming a rolling element circulation passage is formed separately from the body of a movable element so as to allow easy formation of the resin-formed body, and this resin-formed body is suitable for being incorporated into the body of the movable element ensuring an integral formability of the maximum number of unit parts to define the rolling element circulation passage.

In order to achieve the antimation objective, linear motion guidance equipment comprises:

a guide element provided with a running track of a rolling element, and

a movable element arranged so as to be movable along the guide element through a large number of rolling elements, said movable element being provided with (i) a counter-track of a rolling element corresponding to the raceway of rolling elements of said guide member, (ii) a rolling element return passage disposed away from said rolling element counter raceway by a prescribed distance and parallel thereto, and (iii) a pair of direction change passages for connecting the counter-race of the rolling element and the return passage of the rolling element to allow circulation of the rolling elements,

characterized by the fact that:

a resin-formed body for forming a rolling element circulation passage comprises a pair of rolling element passage-forming portions extending along both longitudinal sides of said rolling element counter-race, a return passage forming portion for forming the rolling element return passage and a pair of direction change passage inner guide forming portions for forming inner peripheral guide portions of said direction change passageways, said resin-formed body being separately formed from a body of said movable member; And

at least two portions of (a) said rolling element passage forming portions, (b) said return passage forming portion, (c) one of said pair of direction change passage inner guide forming portions and (d) another of said pair of direction change passage inner guide forming portions are connected to each other through integral molding so that said resin-formed body may be incorporated into the body of said movable element.

Embodiments of the combination of these portions (a) through (d) for the resin-formed body to form the rolling element circulation passage may include the following three examples:

the first example wherein the resin-formed body comprises (i) an integral body of the rolling element passage forming portions and the pair of inner guide forming portions of the change-of-direction passage, and (ii) the portion return passage formation formed separately from the integral body

the second example wherein the resin-formed body comprises (i) an integral body in the rolling element passage forming portions, the return passage forming portion and one of the inner guide forming portions of change passage direction, and (ii) another of the pair of inner guide forming portions of change of direction formed separately from the integral body; and

the third example wherein the resin-formed body is fabricated by preparing an integral body of the pair of rolling element passage forming portions, the return passage forming portion and the pair of inner guide passage forming portions of change of direction, thereby dividing the pair of rolling element passage forming portions and return passage forming portion into longitudinal intermediate portions thereof into two respective parts.

According to the present invention, the resin-formed body for forming the rolling element circulation passage is formed separately from the movable element body. Even though the movable member has a large size, the flow of molten resin is therefore not restricted by the movable member body unlike the conventional prior art, in which the movable member body and the resin-formed body are formed. integrally with each other, and it is possible to ensure an appropriate course of the molten resin by increasing the number of casting attacks in the mold, thus leading to excellent formability. In general, it is difficult to obtain an appropriate course of the molten resin especially in the passage forming portions of the rolling element which extend along the longitudinal sides of the running mating track of the rolling element, and it is therefore effective to separately form the formed body. resin from the body of the movable member in the same manner as the present invention.

The rolling element circulation passage is formed by the resin-formed body. Hence the direct positioning can be achieved in the relative position relationship between the change-of-direction inner guide form portions and the rolling element passage forming portion, as well as in the relative position relationship between the forming portions. direction change passage inner guide and the return passage forming portion, and the continuity of the rolling element circulation passage is appropriately ensured, thereby leading to smooth running of rolling elements.

Since the rolling element passage forming portions are located along the two longitudinal sides of the rolling element counter raceway, the change-of-direction inner guide forming portions having an appropriate relative position relationship with the rolling element passage forming portions are precisely placed on both ends of the rolling element counter race.

Maintaining an appropriate relative position relationship of the change direction passage inner guide forming portions with the rolling element return passage determines that the change direction passage inner guide forming portions are precisely connected to the inner surface of the rolling element return passage.

Especially, a change of direction of travel of the rolling elements takes place in the area of connection of the rolling element passage forming portions with the inner guide forming portions of the change of direction passage as well as in the area of connection of the inner guide forming portions of change of direction with the return passage forming portion. When two portions in such a connecting area are connected to each other by integral forming, a stage is not required to assemble these two portions, thus making it possible to ensure smooth continuity of these two portions without being affected by one. mounting accuracy.

The rolling element return passage may be a through hole formed in the movable element body, the resin-formed body may comprise the pair of change-of-direction passage inner guide forming portions and the passage forming portions. rolling element extending along the two longitudinal sides of the rolling element counter raceway, and the rolling element passage forming portions and at least one of the pair of change passage inner guide forming portions direction can be connected to each other through integral forming.

When the rolling element passage forming portions and the change of direction passage inner guide forming portions are integrally formed with each other so as to provide a smooth connecting area in this manner, it is It is possible to obtain smooth running of the rolling elements in the connection area of these portions, thus improving the circulation property of the rolling element without providing any back passage forming portion made of resin. This structure determines an easy manufacture of the apparatus due to the absence of the return passage forming portion.

The present invention may have additional features whereby a rolling element retainer is provided, the rolling element retainer being adapted to retain the rolling elements in a train with a prescribed distance maintained between two adjacent ones of the rolling elements. rolling element, the rolling element retainer having side edge portions protruding from both sides of each of the rolling elements, and guide grooves for guiding the side edge portions of the rolling element retainer are formed on a whole periphery of the rolling element circulation passage.

The present invention may have additional features whereby a retaining portion is provided on the passing forming portion of the rolling element, to prevent the rolling element retaining device from being out of place, when the moving element is removed from the guide element, and the guide portion is continuously formed over the entire periphery of the rolling element circulation passage for guiding the side edge portions of the rolling element retainer.

Such presence of the rolling element retaining device allows the smooth running of the rolling elements by means of the rolling element retaining device, due to an appropriate continuity maintenance of the guide portion for the rolling element retaining device.

Since the guiding portion for the rolling element retaining device having a small thickness is not formed by inserting the body of the movable element into the mold then injecting molten resin into the mold, but is formed separately from the body of the movable element , the position of the casting connections can be freely determined without being limited by the body of the movable element, with the result that the molten resin can reach, during the formation of the guide portion, the entire space for it, which is formed. in the mold.

The present invention may have additional features whereby each of the direction change passage inner guide forming portions has a thin sheet portion, which is to be brought into contact with the end face of the movable member body, and each inner guide forming portions of the change of direction passage are connected to the back passage forming portions by the thin sheet portion.

When each of the direction change passage inner guide forming portions is connected to the rolling element passage forming portions by the thin sheet portion, the deformation of the thin sheet portion can absorb distortion that occurs between the change direction passage inner guide forming portion and rolling element passage forming portion, or between the change direction passage inner guide forming portion and return passage forming portion. Thus, it is possible to maintain a precise position relationship between the end of the change-of-direction inner guide forming portion and the rolling element passage forming portion or between the inner guide forming portion of the change of direction. change of direction and the forming portion of a return pass.

The thin sheet portion is pushed against the flat end face of the movable member body by a clamping force which is applied to the side cover plate. The position of the change-of-direction inner guide forming portion can then be corrected through deformation of the thin sheet portion, even when the change-of-direction inner guide forming portion is not fully positioned relative to the face. end of the movable element. In addition, the thin sheet portion can be firmly secured between the side cover plate and the body of the movable member by the clamping force, which is applied to the side cover plate, thus preventing the inner guide forming portion change of direction passage is placed incorrectly.

The apparatus of the present invention can have the structure whereby the guide member comprises a guide rail; the movable element comprises a movable block, which is provided with a horizontal portion, which looks towards an upper surface of the guide rail and a pair of wing portions between which the guide rail is held in the right and left side surfaces thereof ; two sets of rolling elements are disposed in a gap between the upper surface of the guide rail and the lower surface of the movable block, and a single train of rolling elements is disposed in each of the interspaces between the right and left side surfaces of the rail guide and both wing portions, so as to provide a total number of trains of four.

The apparatus of the present invention can have the structure whereby the guide member comprises a guide rail; the movable element comprises a movable block, which is provided with a pair of wing portions, between which the guide rail is held on its right and left side surfaces; and two trains of the rolling elements are disposed in each of the interspaces between the left and right side surfaces of the guide rail and both wing portions, so as to provide a total number of trains of four.

In these cases, the respective four inner guide formed portions of change of direction can be formed in an integral body, or the respective two inner guide forming portions of change of direction in each of the right and left sides of the block. movable can be formed into an integral body.

The apparatus of the present invention can have the structure whereby the guide member comprises a guide rail; the movable element is provided with a horizontal portion, which looks towards the upper surface of the guide rail and with a single wing portion which looks towards a lateral surface of the guide rail; a single train of rolling elements is disposed in a gap between the one side surface of the guide rail and the single wing portion, and another single train of rolling elements is disposed in a gap between the top surface of the guide rail guide and a lower surface of the horizontal portion in proximity to a corner of the guide rail.

The apparatus of the present invention can have the structure whereby the guide member comprises a guide rail; the movable element comprises a movable block, which is provided with a pair of wing portions, between which the guide rail is held on two right and left side surfaces; and a single train of rolling elements is disposed in each of the interspaces between the left and right side surfaces of the guide rail and both wing portions, so as to provide a total number of trains of 2.

The apparatus of the present invention can have the structure whereby the guide member comprises a guide rail; the movable element comprises a movable block disposed along a lateral surface of the guide rail, and two trains of the rolling elements are disposed in a gap between a lateral surface of the guide rail and the movable block.

The apparatus of the present invention may have the structure whereby the guide member comprises a splined shaft, and the movable member comprises an outer tube, which is movably supported on the splined shaft through a plurality of trains of the rolling elements.

In addition, in accordance with the present invention there is also provided a linear motion guide apparatus comprising:

a guide rail provided with two raceways of the rolling element on each of the right and left side surfaces of the guide rail, so as to provide the total number of raceways of the rolling element of four; and

a movable block provided with a pair of wing portions, between which the guide rail is held on its right and left side surfaces, each of said wing portions having on its inner surface two counter-tracks of the rolling element corresponding to said two raceways of the rolling element of the guide rail, so as to provide a total number of counter-races of the rolling element of four, said movable block having four endless circulation passages which are formed by four return passages rolling element arranged parallel to said four rolling element running mating tracks, respectively, and rolling element return passages for connecting both ends of each of said four rolling element running mating tracks with both ends of each of said four rolling element return passages, respectively,

characterized by the fact that:

a resin-formed body comprises, for each of said endless circulation passages, a pair of rolling element passage-forming portions extending along both longitudinal sides of said counter-race of rolling element rolling element, a back passage forming portion for forming the rolling element return passage and a pair of change direction passage inner guide forming portions for forming inner peripheral guide portions of said direction change passages said resin-formed body being formed separately from a body of said movable block;

said resin-formed body is divided into two body parts are arranged on the wing portions of the movable block, respectively, so as to form the two endless circulation passages in an inner side of each of the wing portions; And

in each of the two body parts, the rolling element counter-race and the pair of change-of-direction passage inner guide forming portions are formed into an integral body, and the passage forming portion return is formed separately from said integral body.

According to the present invention, a resin-formed body for forming the rolling element circulation passage is formed separately from the movable block body. Although the movable block has a large size, the flow of molten resin is therefore not restricted by the movable block body, unlike the conventional prior art in which the movable block body and the resin-formed body are integrally formed. with each other, and it is possible to ensure an appropriate course of the molten resin through an increase in the number of casting attacks in the mold, thus leading to excellent formability. In general, it is difficult to obtain an appropriate course of molten resin, especially in the passage forming portions of the rolling element which extend along the longitudinal sides of the running counter track of the rolling element, and is therefore effective to separately form the formed body. resin from the movable block body in the same manner as in the present invention.

Especially since the resin-formed body is divided into two body parts, each of which forms two endless circulation passages, proper flow of the molten resin can be ensured, even when the movable block block has a wider width. great .

The rolling element circulation passage is formed by the resin-formed body. Hence, direct positioning in the relative position relationship between the change-of-direction passage inner guide forming portions and the rolling element passage-forming portion can be achieved, as well as in the relative position relationship between the change-of-direction portions. change-of-direction inner guide formation is the return passage forming portion, and the continuity of the rolling element circulation passage can be appropriately ensured, thereby leading to smooth running of the rolling elements.

Since the rolling element passage forming portions are located along the two longitudinal sides of the rolling element counter-race, the change-of-direction inner guide forming portions having an appropriate relative position relationship with the rolling element passage forming portions, they are precisely placed on both ends of the rolling element running counter track.

Maintaining an appropriate relative position relationship of the change direction passage inner guide forming portions with the rolling element return passage causes the change direction passage inner guide forming portions to be precisely connected. to the inner surface of the rolling element return passage.

Especially, a change in a direction of travel of the rolling elements takes place in the area of connection of the rolling element passage forming portions with the inner guide forming portions of. change of direction passage. When these two portions in that connection area are connected to each other by integral forming, a stage is not required to assemble these two portions, thus making it possible to ensure smooth continuity of these two portions without being affected by accuracy. by Assembly.

The present invention may have additional features whereby a rolling element retainer is provided, the rolling element retainer, being suitable for retaining the rolling elements in a train with a prescribed distance maintained between two adjacent elements. rolling element, the rolling element retainer having side edge portions projecting from both sides of each of the rolling elements; and guide grooves for guiding the side edge portions of the rolling element retainer are formed over the entire periphery of the rolling element circulation passage.

Such presence of the rolling element retaining device allows for smooth running of the rolling elements by means of the rolling element retaining device, due to an appropriate continuity maintenance of the guide portion for the rolling element retaining device.

Since the guide portion for the rolling element retainer which has a small thickness is not formed by inserting the movable block body into a mold then injecting molten resin into the mold, but is formed separately from the movable block body, positions of the casting attachments can be freely determined without being limited by the body of the movable block, with the result that the molten resin can reach during the formation of the guide portion, the entire space for it, which is formed in the mold.

The present invention may have additional features whereby each of the direction change passage inner guide forming portions has a thin sheet portion, which is to be brought into contact with the end face of the movable block body, and each of the change of direction inner guide forming portions is connected to the rolling element passage forming portions or to the back passage forming portion by the thin sheet portion.

When each of the change direction passage inner guide forming portions is connected to the rolling element passage forming portions by the thin sheet portion, a deformation of the thin sheet portion can absorb distortion occurring between the change direction passage inner guide forming portion and rolling element passage forming portion, or between the change direction passage inner guide forming portion and return passage forming portion. Accordingly, it is possible to maintain precise position adjustment between the end of the change-of-direction inner guide forming portion and the rolling element transition-forming portion or between the inner guide forming portion of change of direction. direction and the forming portion of return passage.

The thin plate portion is pushed against the flat end face of the movable member body by a clamping force which is applied to the side cover plate. The position of the change direction passage inner guide forming portion can then be corrected through a deformation of the thin plate portion, even when the change direction passage inner guide forming portion is not correctly positioned relative to the face. of the body of the movable block. In addition, the thin plate portion can be securely secured between the side cover plate and the body of the movable block by the clamping force, which is applied to the side cover plate, thus preventing the inner guide forming portion from change of direction passage is placed incorrectly.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a schematic disassembled perspective view illustrating a movable block of a linear motion guide apparatus of the first embodiment of the present invention;

Figure 2 shows a resin frame member as shown in Figure 1 as one of the resin formed bodies, to form a ball circulation passage and, more specifically, Figure 2 (a) is a front view of the resin frame member resin frame, figure 2 (b) is a side view thereof, figure 2 (c) is a sectional view cut along the line C-C as indicated in figure 2 (a), figure 2 (d) and a sectional view cut along line D-D as indicated in figure 2 (d), figure 2 (e) is an enlarged sectional view cut along line E-E as indicated in figure 2 (a) and figure 2 (f) is an enlarged sectional view enlarged section cut along the line F-F as indicated in figure 2 (a);

Figure 3 (a) is a front view having a section, illustrating the linear motion guide apparatus of the first embodiment of the present invention as shown in Figure 1, Figure 3 (b) is a front view of the apparatus as shown in Figure 3 (a), in which a portion of the half of the side cover plate is omitted, and Figures 3 (c) to (f) are partial sectional views illustrating embodiments of the structure of the portion forming a passageway spheres and their proximity as shown in figure 3 (a);

Figure 4 (a) is a side view having a partial section of the linear motion guide apparatus of the first embodiment of the present invention, Figure 4 (b) is a sectional view of a ball circulation passage of the movable block as shown in Figure 4 (A), from which the ball retainer is removed, Figure 4 (c) is a partial side view of the ball retainer, Figure 4 (d) is a top view plan of the ball retainer as shown in Figure 4 (c) and Figure 4 (e) is a view of the ball retainer as viewed in a direction of an arrow of "a" as indicated in Figure 4 ( d);

figure 5 shows a side cover plate of the movable block and, more specifically, figure 5 (a) is a front view of the side cover plate, figure 5 (b) and a rear view of it figure 5 (c ) is a cross-sectional view thereof in its central portion;

Figures 6 (a) to 6 (i) are descriptive views illustrating steps for assembling the movable block as shown in Figure 1;

Figure 7 (a) is an enlarged partial view of the direction change passage as shown in Figure 4 (b), Figure 7 (b) is a partial side view of the direction change passage as shown in Figure 4b (b ), in which the side cover plate is removed, Figure 7 (c) is a partial side view illustrating a recess portion, which forms the direction change passage in the side cover plate as shown in Figure 7 (a ), Figure 7 (d) is a partial sectional view of an outer peripheral side half tubular element to form a part of a resin tube as shown in Figure 7 (a), Figure 7 (e) is a view side of the outer peripheral side half tubular element as shown in Figure 7 (d), Figure 7 (f) is a partial sectional view of an inner peripheral side half tubular element to form another part of the resin tube as shown in Figure 7 (a) and, Figure 7 (g) is a side view of the inner peripheral side half tubular element as shown in Figure 7 (f);

Fig. 8 is a schematic disassembled perspective view illustrating a first modification of the resin-formed body to form a ball circulation passage in the first embodiment of the present invention;

Figure 9 (a) is a disassembled side view having a partial section, illustrating the resin-formed body for the ball circulation passage as shown in Figure 8, Figure 9 (b) is a view which illustrates the first resin frame of the resin-formed body, Figure 9 (c) is a view illustrating its second resin frame, Figure 9 (d) is a rear view of the first resin frame, and Figure 9 (e) is a rear view of the second resin frame;

Fig. 10 is a schematic disassembled perspective view illustrating the second modification of the resin body for forming the ball circulation passage in the first embodiment of the present invention;

Figure 11 (a) is a disassembled side view having a partial section, illustrating the resin-formed body for the ball circulation passage as shown in Figure 10, Figure 11 (b) is a side view illustrating the connecting end of one of the split resin frames as shown in Figure 11 (a) and Figure 11 (c) and an enlarged sectional view illustrating the connecting portion of the resin frames;

Fig. 12 is a schematic disassembled perspective view illustrating the third modification of the resin-formed body for forming the ball circulation passage in the first embodiment of the present invention;

Figure 13 (a) is a side view having a partial section illustrating the linear motion guide apparatus, in which the movable block is employed as shown in Figure 12, and Figure 13 (b) is a sectional view a resin-formed body for forming the ball circulation passage as shown in FIG. 13 (a);

Figure 14 (a) is an enlarged partial sectional view of the change of direction passage as shown in Figure 13 (b), which is formed in the side cover plate removed from the ball passage forming portion, Figure 14 ( b) is a partial sectional view illustrating the side cover as shown in Figure 14 (a) which is attached to the ball passage forming portion, Figure 14 (c) is a partial side view illustrating the forming portion ball passage, where the side cover plate as shown in Figure 14 (a) is removed, and Figure 14 (d) is a partial side view illustrating a recessed portion, which forms the direction change passage in the side cover plate as shown in figure 14 (a);

Fig. 15 is a schematic disassembled perspective view illustrating the fourth modification of the resin-formed body for forming the ball circulation passage in the first embodiment of the present invention;

Figures 16 (a) to 16 (h) are descriptive views illustrating the other ball train arrangement embodiments of the linear motion guide apparatus of the first embodiment of the present invention;

Figure 17 is a perspective view illustrating structural elements other than the resin-formed body for forming the ball circulation passage of the linear motion guide apparatus as shown in Figure 16 (a), which is provided with two trains of spheres on each of the two sides; Figure 18 is a schematic disassembled perspective view illustrating a movable block of a linear motion guide apparatus of the second embodiment of the present invention;

Figure 19 (a) is a front view illustrating the linear motion guide apparatus of the second embodiment of the present invention as shown in Figure 18, Figure 19 (b) is a partial sectional view illustrating a circulation passage of balls of the apparatus as shown in Figure 19 (a), Figure 19 (c) is a partial plan view of the roller retainer as shown in Figure 19 (b), and Figure 19 (d) is a view of the roller retaining device, with the view being placed in the direction of an arrow of "d" as indicated in FIG. 19 (c);

Figure 20 shows the formed-of-resin body to form the ball circulation passage as shown in Figure 18, and more specifically, Figure 20 (a) is a sectional view cut along line a-a as indicated in Figure 20 (b) Figure 20b is a front view of the resin formed body for forming the ball circulation passage as shown in Figure 20 (a), Figure 20 (c) is a partial side view of the formed body. di-resin to form the ball circulation passage, wherein the resin tube as shown figure 20 (a) is removed, figure 20 (d) is a sectional view of an outer peripheral side half tubular element to form a part of a resin tube as shown in figure 20 (a), figure 20 (e) is a side view of the outer peripheral side half tubular element as shown in figure 20 (d), figure 20 (f ) is a sectional view of an inner peripheral side half tubular member to form another pa rte of the resin tube as shown in figure 20 (a), figure 20 (g) is a side view of the inner peripheral side half tubular element as shown in figure 20 (f) and figure 20 (h) is a partial sectional view illustrating the structural example of the roll passage forming portion in which the roll retaining device is not employed;

Fig. 21 is a schematic disassembled perspective view illustrating the first modification of the resin-formed body to form the ball circulation passage in the second embodiment of the present invention; Figure 22 (a) is a disassembled side view having a partial section illustrating the resin-formed body for the ball circulation passage as shown in Figure 21, Figure 22 (b) is a view illustrating the first resin frame as shown in Figure 22 (a) with the view placed on its split end side and Figure 22 (c) and a view illustrating the second resin frame as shown in Figure 22 (a) with the vision which is placed on its split end side;

23 is a schematic disassembled perspective view illustrating the second modification of the resin-formed body for forming the ball circulation passage in the second embodiment of the present invention; Figure 24 (a) is a disassembled side view having a partial section showing the resin-formed body for the ball circulation passage as shown in Figure 23, Figure 24 (b) is a view which illustrates a resin frame as shown in Figure 24 (a), with the view being placed on its split end side, and Figure 24 (c) is a view illustrating the other resin frame as shown in Figure 24 (a) with the vision being placed on its split end side;

Fig. 25 is a schematic disassembled perspective view illustrating the third modification of the resin-formed body to form the ball circulation passage in the second embodiment of the present invention; Fig. 26 is a schematic disassembled perspective view and illustrates the fourth modification of the resin-formed body for forming the ball circulation passage in the second embodiment of the present invention; Fig. 27 is a front view having a half sectional portion, illustrating the other embodiment of ball train arrangement in the linear motion guide apparatus of the second embodiment of the present invention;

Fig. 28 is a schematic disassembled perspective view of an outer tube in ball and groove unit as linear motion guide apparatus of the third embodiment of the present invention;

Figure 29 (a) is a front view having a section illustrating the ball and groove unit of the third embodiment of the present invention in which the outer tube is employed as shown in Figure 28, Figure 29 (b) is a view partial sectional view illustrating an apparatus ball passage as shown in Figure 29 (a) and Figure 29 (c) is a disassembled sectional view illustrating the structure of the ball circulation passage, in which the roll retainer as shown in FIG. 29 (b) is removed;

Figure 30 shows the formed-of-resin body to form the ball circulation passage as shown in Figure 29 and, more specifically, Figure 30 (a) is a sectional view cut along line a-a as indicated in Figure 30 (b), Figure 30 (b) is a front view of the resin-formed body for forming the ball circulation passage as shown in Figure 30 (a), Figure 30 (c) is a partial side view of the formed-of-resin body to form the ball circulation passage, wherein the resin tube as shown in figure 30 (a) is removed, figure 30 (d) is a sectional view of a side half tubular element outer peripheral to form a part of a resin tube as shown in figure 30 (a), figure 30 (e) is a side view of the outer peripheral side half tubular element as shown in figure 30 (d), figure 30 (f) is a sectional view of an inner peripheral side half tubular member to form a halt part of the resin tube as shown in Figure 30 (a) and Figure 30 (g) is a side view of the inner peripheral side half tubular element as shown in Figure 30 (f);

Fig. 31 is a schematic disassembled perspective view illustrating the first modification of the resin-formed body to form the ball circulation passage for the third embodiment of the present invention; Figure 32 (a) is a disassembled side view having a partial section, illustrating the resin-formed body for the ball circulation passage as shown in Figure 31, Figure 32 (b) is a view which illustrates the first resin frame as shown in Figure 32 (a) with the view being placed on its split end side and Figure 32 (c) is a view illustrating the second resin frame as shown in Figure 32 (a ), with the vision being placed on its split end side;

Fig. 33 is a schematic disassembled perspective view illustrating the second modification of the resin-formed body for forming the ball circulation passage in the third embodiment of the present invention;

Figure 34 (a) is a disassembled side view having a partial section illustrating the resin-formed body for the ball circulation passage as shown in Figure 33, Figure 34 (b) is a view illustrating one resin frame as shown in Figure 34 (a) with the view being placed on its split end side and Figure 34 (c) is a view illustrating the other resin frame as shown in Figure 34 (a) with the sight being placed on its split end side;

Fig. 35 is a schematic disassembled perspective view illustrating the third modification of the resin-formed body for forming the ball circulation passage in the third embodiment of the present invention;

Figure 36 is a schematic disassembled perspective view illustrating the fourth modification of the resin-formed body for forming the ball circulation passage in the third embodiment of the present invention; Figure 37 is a front view having a partial section, illustrating another embodiment of the arrangement of the ball trains in the groove and ball as a linear motion guide apparatus of the third embodiment of the present invention;

Figure 38 (a) is a front view having a partial section illustrating a groove and roller unit as a linear motion guide apparatus of the fourth embodiment of the present invention, in which a side cover plate is removed, and Figure 38 (b) is a partial longitudinal sectional view of a roller circulation passage as shown in Figure 38 (b);

Figure 39 (a) is a partial sectional view illustrating the structural example of the resin-formed body for forming the roller circulation passage in the roller grooves as shown in Figure 38, and Figure 39 (b) 39 (c) are views illustrating the first to fourth modification of the resin-formed body for forming the roll circulation passage;

Figure 40 (a) is a front view of the movable block of the linear motion guide apparatus of the fourth embodiment of the present invention, in which the side cover plate is removed, and Figure 40 (b) is a perspective view of the movable block as shown in Figure 40 (a);

Figure 41 is a schematic disassembled perspective view of the resin bodies formed to form the ball circulation passage as shown in Figure 40;

Figure 42 is a front view of the resin frame composing the resin formed body to form the ball circulation passage as shown in Figure 41, Figure 42 (b) is a left side view of the formed body of resin as shown in Figure 42 (a) and Figure 42 (c) is a right side view of the resin formed body as shown in Figure 42 (a);

Figure 43 shows a resin tube for forming a resin-formed body part to form the ball circulation passage, as shown in Figure 41 and, more specifically, Figure 43 (a) is a front view of a outer peripheral side half tubular element, Figure 43 (b) is a side view of the outer peripheral side half tubular element as shown in Figure 43 (a), Figure 43 (c) is a front view of a tubular element of inner peripheral side half, Figure 43 (d) is a side view of the inner peripheral side half tubular element as shown in Figure 43 (c); And

Figure 44 (a) is a sectional view of a ball circulation passage, in which the ball retainer is removed from the movable block as shown in Figure 40 (a), Figure 44 (b) is a view enlarged partial view of the change of direction passage as shown in Figure 44 (a), Figure 44 (c) is a partial side view of the ball retainer, Figure 44 (d) is a plan view of the retainer of sphere as shown in Figure 44 (c), Figure 44 (e) is a view of the ball retainer, with the view placed in an arrow direction of "a" as indicated in Figure 44 (d) , Figure 44 (f) is a partial side view of the change of direction passage as shown in Figure 44 (b), in which the side cover plate is removed, and Figure 44 (g) is a partial side view illustrating a recess portion, which forms the direction change passage in the side cover plate such as mo layer in Figure 44 (b).

DETAILED DESCRIPTION OF THE REALIZATIONS

FAVORITE

Now, embodiments of a linear motion guide apparatus of the present invention will be described in detail below with reference to the accompanying drawings.

[FIRST REALIZATION]

Figures 1 through 7 show a linear motion guide apparatus of the first embodiment of the present invention.

The linear motion guiding apparatus 1 is provided with a guide rail 2 as the guiding element, which extends linearly and with a movable block 4 as a movable element, which is arranged so as to be movable along the guide rail 2 through a large number of balls 3 such as rolling elements.

The guide rail 2 is formed in a long bar shape having a rectangular section. Two ball race grooves 5, 5 'as rolling element race views are formed in the horizontal top surface of guide rail 2 and a single ball race groove 5 as rolling member race track is formed on each of the right and left vertical surfaces of the guide rail 2, so as to provide a total number of grooves 5 of four.

The movable block 4 is formed as a block body having an inverse U-shaped cross section, with its opening end directed downward. The block body is provided with a horizontal portion 6 and towards the upper surface of the guide rail 2 is a pair of wing portions 7,7 which extend downwards from the right and left ends of the horizontal portion 6 and face towards the right and left side surfaces of the guide rail 2, respectively. The horizontal portion 6 has on its lower surface two ball race counter-grooves 8,8 as a rolling element race counter, which correspond to the ball race grooves 5,5 formed on the upper surface of the guide rail 2. Each of the wing portions 7,7 has, on its inner surface, a single ball race counter-groove 8 as a rolling element counter-race, which corresponds to the respective ball race grooves 5,5 formed on the right-hand side surfaces. and left guide rail 2.

In addition, four ball return passages 9, 9, 9, 9 are formed in the movable block 4 as the rolling element return passage, which are provided parallel to the four ball run counter-grooves 8, 8, 8, 8 , respectively, as well as four pairs of direction change passages 10, 10, 10, 10 each having a U-shape, for connecting the two respective ends of the ball running counter-grooves 8, 8, 8, 8 with the two respective ends of the ball return passages 9, 9, 9, 9 so as to form four endless circulation passages. The ball return passages 9, 9 respectively corresponding to the ball race grooves 5, 5 on the upper side of the guide rail 2 are formed in the horizontal portion 6. The other ball return passages 9, 9 respectively correspond to the grooves 5 , 5 of running balls formed on the right and left vertical surfaces of the guide rail 2 are formed in the wing portions 7, 7 of the movable block 4, respectively.

In each of the four endless circulation passages in the present embodiment, the balls 3 are held in the form of a train by a ball retainer 12 as a rolling element retainer, as shown in FIG. 4, so that the balls 3 can be circulated as they are guided by the ball retainer 12.

The ball retaining device 12 comprises a flexible tape portion 12b which is provided with ball holes 12a for receiving the balls 3 respectively and with spacing portions 12c provided between the two adjacent balls 3, 3. The tape portion 12b has a width greater than the diameter of the sphere 4 so that both lateral edges of the ribbon portion 12b extend outside the sphere 3.

The spacing portion 12c is provided with a spherical ball support cavity 12d corresponding to the spherical surface of the ball 3. The ball 3 is supported on its two sides by a pair of spherical support cavities 12d so as to prevent the ball 3 comes out of the belt portion 12b. In this embodiment, the one end of the ribbon portion 12b is not connected to its other end, thus forming a strip-like ribbon having the two ends. One end of the ribbon portion 12b can be connected to its other end to form an endless ribbon.

The movable block 4 is composed of a block body 13 having counter-grooves 8, 8, 8, 8, for running the balls, a body formed of resin 20 to form passages for circulation of balls, which is inserted in the body of block 13, and a pair of side cover plates 40, 40 fixed to the two end surfaces of the block body 13, into which the resin-formed body 20 is inserted.

Each of the ball circulation passages of the resin formed body 20 comprises a pair of ball passage forming portions 21, 21 extending on the two longitudinal sides of the ball run counter-groove 8, a pair of portions 22, 22 of internal change-of-direction passage guide formation provided on the two side surfaces of the block body 13, and a resin tube 23 as a return passage formation portion, which is inserted into a through hole formed in the block body 13. In this embodiment, the ball passage forming portions 21, 21 and the pair of internal change direction passage guide forming portions 22, 22 are integrally formed with each other in an integral body, and the resin tube 23 it is formed separately from the integral body mentioned above. More specifically, a structure is employed whereby the ball passage forming portions 21, 21 and the pair of internal change direction passage guide forming portions 22, 22 are integrally connected to each other through an integral forming to form an integral resin frame 24, and the four resin tubes 23 can respectively be inserted into the block body 13.

The portions 21, 21 which form ball passage are provided with guide grooves for guiding the two lateral edges of the belt portion 12b of the ball retaining device 12 in a loaded area. The guide grooves can prevent the ball retainer 12 not only from oscillating during the travel of the ball, but also from flexing by engaging the side edges of the band portion 12b with the groove 21a, when the movable block 4 is removed. by guide rail 2. The balls are supported by the ball retainer 12. More specifically, the ball retainer 12 is supported by a jaw portion of the guide groove 21a, with the result that the balls 3 are held in their proper position so as not to come out of the movable block 4.

In this embodiment, a distance between the pair of portions 21, 21 forming the passage of balls placed parallel to each other on the two longitudinal sides of the counter groove 8 of the ball run is slightly larger than the diameter of the ball 3. The ball 3 comes out of the ball run counter-groove 8, and the ball retaining device 12 is not used. When the protrusion extent of the jaw portion 21b is predetermined so that a distance between the pair of portions 21, 21 forming the ball passage is slightly smaller than the diameter of the ball 3 as shown in figure 3 (d) it is however possible prevent the ball 3 from coming out of the ball running counter-groove 8, even without the ball retaining device 12. This structure can be applied not only to the case in which the balls 3 are inserted into the ball circulation passage with the use of the ball retaining device 12, but also in the case in which the balls are inserted into it without the retaining device. 12 of sphere. The distance between the pair of portions 21, 21 which form ball passages can be slightly smaller than the diameter of the ball 3, so that the portions 21, 21 forming the ball pass directly hold the ball 3 without using the device. ball retainer 12 as shown in FIG. 3 (e).

Guide grooves 9c, 10c are also formed in the ball return passage 9 and direction change passage 10 as unloaded areas in order to guide the side edges of the belt portion 12b. The guide grooves 9c, 10c are connected to the aforementioned guide groove 21a in the loaded area so as to form an endless groove in the entire periphery.

When the ball retaining device 12 is not employed as shown in FIG. 3 (f), the distance between the pair of ball passage forming portions 21, 21 disposed on the two longitudinal sides of the ball travel counter-groove 8, the which portions have no jaw part 21, may be slightly smaller than the diameter of the ball 3, thereby preventing the ball 3 from coming out of the ball run counter groove.

The four series of portions 21, 21 that form the ball passage are composed of the first thin connecting plate portion 25 which extends longitudinally along the lower surface of the horizontal portion 6 of the block body 13, by a pair of second plate portions connecting elements 26, 26 which have the L-shaped cross section and extend in the longitudinal direction of the block body 3 along the corner portions between the horizontal portion 6 and the wing portions 7, 7 of the block body 13, and by a pair of third connecting plate portions 27, 27 extending in the longitudinal direction of the block body 13 along the lower surfaces of the wing portions 7, 7 of the block body 13.

More specifically, the right and left side edges of the first connecting plate portion 25 and the upper edges of the pair of second right and left connecting plate portions 26, 26 are located on the two sides of the respective ball running counter-grooves 8 , 8 provided on the lower surface of the horizontal portion 6, so as to form portions 21, 21; 21, 21 of formation of ball passage. The lower edges of the second connecting plate portions 26, 26 and the inner edges of the third connecting plate portions 27, 27, are located on the two sides of the respective counter-grooves 8, 8 for running the balls provided on the respective internal surface of the portions. wing-shaped 7, 7, so as to form the other portions 21, 21; 21, 21 of formation of passage of spheres.

The inner guide forming portion 22 of the change of direction passage has a thin plate portion 29 which is to be connected to the end surface of the block body 13.

The ball pass-forming portions 21, 21 and the resin tube 23 are connected through the aforementioned thin plate portion 29. In this embodiment, the change-of-direction internal guide forming portions 22, 22 and the ball passage forming portions 21, 21 are connected by the thin plate portion 29 through integral forming. The resin tube 23 is inserted into the hole 24 formed on the thin plate portion 29 so as to make a tap joint, and fixed to the thin plate portion 29.

The thin plate portion 29 has the first end plate part 30 corresponding to the end surface of the horizontal portion 6 of the block body 13, a pair of third end plate parts 32, 32 corresponding to the end surfaces of the wing portions 7 , 7 and the second end plate parts 31, 31 to connect the first part to the end plate 30 and the respective third parts to the end plate 32, 32. The first end plate part 30 has portions 22, 22 forming an internal guide change of direction passages which are formed to protrude correspondingly to the two ball trains 3, 3 in the upper surface side of the guide rail 2. Each of the third end plate parts 32, 32 has the forming portion 22 of internal guide of change of direction passage, which is formed so as to project correspondingly to the single train of balls on the lateral surface of the guide rail 2.

The first end plate portions 30, 30 which are to be placed respectively on the two ends of the block body 13 are connected in their lower portion with the two ends of the first connecting plate portion 25 which extends longitudinally between the first pad portions terminals 30, 30. The second terminal plate portions 31, 31, which are to be placed respectively on the two ends of the block body 13 are connected in their inner edge portion with the two ends of the second connecting plate portion 26 which extends longitudinally between the second end plate portions 31, 31. The other second end plate portions 31, 31 have the same connection structure. The third terminal plate portions 32, 32, which are to be placed respectively on the two ends of the block body 13, are connected in their inner edge portion with the two ends of the third connecting plate portion 27 which extends longitudinally between the third end plate portions 32, 32. The other third end plate portions 32, 32 have the same connection structure. A single resin frame 24 is formed in this way.

Each of the change-of-direction inner guide forming portions 22 has a semi-cylindrical shape. On the outer periphery of the inner guide forming portion 22 of the change of direction passage, an inner guide groove 10a having a semicircular cross section is formed so as to form the inner guide portion for the change of direction passage 10. A end of the inner guide groove 10a is connected to the end of the ball race counter groove 8. Accordingly, the one end of the inner guide groove 10a has the same cross-sectional shape as the ball run counter groove 8 so as to align one end of the inner guide groove 10a with the end of the counter groove 8 of ball race. The other end of the inner guide groove 10a of the change of direction passage 10 is connected to the end of the ball return passage 9. Consequently, the other end of the inner guide groove 10a has the same cross-sectional shape as the ball return passage 9 so as to align the other end of the inner guide groove 10 with the end of the passage. 9 ball return.

Cylindrical flange portions 33, 33 are formed at both ends of the inner guide groove 10a. The distance between the respective outer surfaces of the cylindrical flange portions 33, 33 is greater than the width of the belt portion 12b. The cylindrical flange portions 33, 33 form a retainer guide groove 10c for the ball retainer 12 in cooperation with a semicircular cavity portion having cutouts, which is formed on the inner periphery of the cover plate cavity 40 described later.

The two ends of the inner guide groove 10a for the direction change passage 10 extend over the contact surface of the first and third end plate portions 30, 32 with the end surface of the block body 13, so as to be connected at the respective ends of the ball run counter-groove 8 and of the ball return passage 9. Holes 34, 34, 34, 34 for inserting the tube having a semicircular shape into which the ends of the resin tube 23 are to be inserted, are formed in the first and third terminal plate portions 30, 32.

As shown in Figure 7, the resin tube 23 is composed of an inner peripheral side half tubular element 23a located in the inner peripheral side of the ball circulation passage, which is continuously connected to the inner guide groove 10a for the passage of direction change, and by an outer peripheral lateral half tubular member 23b located in the outer peripheral side of the ball circulation passage, which is continuously connected to outer guide groove 10b for the direction change passage 10, which is formed on the side cover plate 40. The inner peripheral side half tubular member 23a has a groove portion 9a having a semicircular cross section, and side edge portions 23c extending longitudinally along the groove portion 9a.

The outer peripheral side half tubular member 23b is formed into a linear member having the same circular cross section as the outer guide groove 10b, for the change of direction passage, which is formed on the side cover plate 40. The outer peripheral side half tubular element 23b has a groove portion 9b, which is connected continuously to the inner guide groove 10b, and the lateral edge portions 23d extending longitudinally along the groove portion 9b. The lateral edge portions 23d are provided on their protruding outer edges and 23e which are to be brought into contact with the outer edges of the lateral edge portions 23c of the inner peripheral lateral half tubular element 23a to form the guide groove 9c retaining device for the ball retaining device 12.

The inner peripheral side half tubular element 23a of the resin tube 23 has the same length as the block body 13. The inner peripheral side half tubular element 23a is positioned to be brought into contact with the rear surface of the portion 22 of formation of internal guide of passage of change of direction.

The outer peripheral lateral half tubular element 23b of the resin tube 23 on the other hand has a greater length than the block body 13 by an amount corresponding to the thickness of the thin plate portion 29. External peripheral lateral half tubular elements 23b are inserted into the insertion holes 34 of the first and third end plate portions 30, 32. A longitudinal position termination of the outer peripheral lateral half tubular element 23b is made by bringing the two ends of the inserted outer peripheral lateral half tubular element 23b in the insertion holes 34 in contact with the peripheral edge of the end portion of the outer guide grooves 10b for the change of direction passage, which are formed on the cover plate 40. The protrusions 23e formed on the two lateral edges of the tubular element outer peripheral side half 23b come into contact with the outer edges of the flange portions a cylindrical shape 33 formed in the change-of-direction passage inner guide forming portion 22 22 to form a part of the guide groove 10c, and the outer peripheral side half tubular element 23b and the inner peripheral side half tubular element 23a are limited to being turned into the insertion hole 14.

The resin tubes 23 and the change-of-direction inner guide forming portions 22 are precisely positioned through insertion holes 34 formed on the first and third end plate portions 30, 32 of the thin plate portion 29 and a appropriate assembly in this way.

As shown in Figure 5, the side cover plate 40 is provided with an insertion recess portion 40a into which the thin plate portion 29 is inserted, of four recess portions 41 having the external guide grooves 10b for the passage of change of direction, in which portions of the inner guide forming parts 22 of change of direction passage, and of screw fixing portions for securing the side cover plate 40 to the block body 13. In the fixing portions a screw, the side cover plate 40 is fixed to the block body 13 by inserting bolts 44 into holes 43 formed on the side cover plate 40 and engaging the bolts with threaded holes 45 formed on the end surface of the block body 13. The holes 43 they are located between the first and third portions of the end plate 30, 32 of the thin plate portion 29.

As shown in FIG. 7, the outer guide groove 10b for the change of direction passage in the recess portion 41 has on its side edges larger diameter arcuate recesses 46 which form the retainer guide groove 10c in cooperation with the cylindrical flange portions 33 of the change-of-direction internal guide forming portions 22, and arcuate recesses 47 of smaller diameter, into which the cylindrical flange portions 33 are inserted, The internal passage guide forming portion direction change 22 provided with the inner guide groove 10a for the direction change passage is adapted in the recess portion 41 of the side cover plate 40, and the thin plate portion 29 is received in the insertion recess portion 40a of the side cover plate 40. The thin plate portion 29 is held between the cover plate side 40 and the end surface of the block body 13 through a clamping force so as to be firmly fixed therebetween.

The change-of-direction inner guide forming portions 22 and the ball pass-forming portion 21 are connected through a thin plate portion 29, thus making it possible to maintain an accurate position relationship of the end of the inner guide groove 10a for the change of direction passage formed in the inner guide forming portion of the change of direction 22 relative to the ball passage forming portions 21, 21, as well as a precise position relationship of the inner guide groove 10a for the change of direction passage relative to the return passage of balls 9.

The thin plate portion 29 located in proximity to the direction change passage inner guide forming portion 22 is uniformly pushed against the flat end surface of the lock body 13 through a clamping force applied to the side cover plate 40 (see figure 7). Even when the change-of-direction inner guide forming portion 22 is not located in a correct position, the thin plate portion 29 changes its shape on the end surface of the block body 13, thus allowing correct positioning of the block body. inner guide forming portion of change-of-direction passage 22.

The thin plate portion 29 is firmly clamped and fixed by a clamping force, which is applied to the side cover plate 40, and a frictional force determined by this clamping step can prevent an unfavorable movement of the internal guide groove 10a for the passage of change of direction.

The side cover plate 40 is attached to the lock body 13 so that the change-of-direction inner guide forming portion 22 assembled in the lock body 13 is fitted into the recess portion 41 in the side cover plate 40. This coupling step allows to perform a precise positioning of the side cover plate 40 relative to the block body 13.

Figure 6 shows assembly for the above-described resin-formed body to form the ball circulation passage.

First, the inner peripheral lateral half tubular element 23a of the resin tube 23 is inserted into the through hole 14 of the block body 13 (see Figures 6 (a) and 6 (b)).

Then, the resin frame obtained by integral formation is inserted into the recess of the body 13, while it is determined that the thin plate portions 29 in the two ends of the resin frame 24 slide on the respective end surfaces of the block body 13 (see figures 6 (c) and 6 (d)). The first connecting plate portion 25 of the resin frame 24 contacts the bottom surface of the horizontal portion 6, thereby effecting a position determination in the vertical direction of the resin frame 24 The second connecting plate portion 26 and the third connecting plate portion 27 of the resin frame come into contact with the respective internal surfaces of the wing portions 7, 7 of the block body 13, thus effecting a determination of the position of the ball passage forming portions 21, 21 and the change direction passage inner guide forming portion 22 (see FIGS. 6 (e) and 6 (f)). At this point, the insertion hole 34 of the thin plate portion 29 is aligned with the through hole 14 of the block body 13.

Then, the outer peripheral lateral half tubular element 23b is inserted into the through hole 14 by the insertion hole 34, thus completing the assembly step of the resin-formed body 20 to form the ball circulation passage (see Figure 6 (g ) and 6 (h)). Then a side cover plate 40 is secured to an end surface of the lock body 13 by a clamping stage, the ball retaining device 12 which holds the balls is inserted, and the other side cover plate 40 is secured to the other end surface of the block body 13 by means of the same tightening study thus completing the assembly stage of the mobile block 4.

According to the present invention, the resin-formed body 20 for forming the ball circulation passage is formed separately from the block body 13. Even when the movable block 4 has a larger size, there is no flow limitation of resin melted by the block body 13, unlike the case where the block body 13 is formed integrally with the resin-formed body 20. An increase in the number of casting attachments formed on the mold can ensure an appropriate course of the mold. cast resin, thus improving formability. Especially, the ball passage forming portions 21, 21 located on opposite longitudinal sides of the ball run groove 8 are thin with the result that the molten resin cannot reach every part of the space to form the portions 21, 21 of formation of passage of spheres. It is therefore effective to form the resin-formed body 20 separately from the block body 13, in accordance with the embodiment of the present invention.

The continuous circulation passage is formed by the resin-formed body 20, and it is thus possible to make a position determination of the inner guide groove 10a for the change-of-direction passage relative to the passage-forming portions 21, 21. balls, as well as a determination of the position of the internal guide groove 10a for the change of direction passage relative to the ball return passage 9, thus ensuring a continuity of the circulation passage so as to facilitate the circulation of the balls 3.

When the proper position relationship of the inner guide groove 10a is maintained for the change of direction passage relative to the ball passage forming portions 21, 21, the ball passage forming portions 21, 21 are located on the two longitudinal sides of the ball run groove 8 so as to be aligned with the ends of the inner guide groove 10 for the change of direction passage.

When the proper position relationship of the inner guide groove 10a for the change of direction passage relative to the ball return passage 9 is maintained, the inner guide groove 10a for the change of direction passage can be aligned with the groove. 23a of the ball return passage 9.

The connecting portion of the ball passage forming portions 21, 21 and the change of direction internal passage guide forming portion 22 is obtained by integral forming, thus allowing the assembly step of the connecting portion to be omitted. Although the direction of travel of the balls 3 is varied in this connecting portion, the integral structure mentioned above can ensure a continuity of the circulation passage, without being influenced by the assembly precision. It is therefore possible to carry out an easy stroke of the balls 3 starting from the passage of the ball run between the ball run groove 5 and the ball run counter-groove 8 to the change of direction passage 10, as well as from the change of direction passage. direction 10 to passage 9 of return of balls.

Descriptions will now be made of modifications of the resin-formed body 20 to form the ball circulation passage, which is divided into parts. In the description of the modifications, modified features will only be illustrated in comparison with the first embodiment of the present invention. The same reference numbers will be assigned to the same components as those in the first embodiment of the present invention, and a description thereof will be omitted.

[First modification]

Figures 8 and 9 show the first modification of the resin-formed body 20 to form the ball circulation passage, which is described in the first embodiment. In the first modification, the resin-formed body 20 for forming the ball circulation passage is composed of the first resin-formed frame 20A, which is obtained by integrally connecting both the ball passage formation portions 21, 21 and the resin tubes 23 at their ends as the change-of-direction internal guide forming portions 22A for one side, and the second resin-formed frame 20B, which is provided with change passage internal guide forming portions direction 22B for the other side, and formed separately from the first resin-formed frame 20A.

In this case, the ball passage forming portions 21, 21 are integrally connected with the change direction passage inner guide forming portions, 22A, through the thin plate portion 29A as in the first embodiment.

The change-of-direction inner guide forming portions 22A are also integrally connected to the resin tubes 23 through a thin plate portion 29A. In this case, the resin tube 23 is formed into an integral tubular body, although half-tube elements are used in the first embodiment. Accordingly, there is no insertion hole 34A in the thin plate portion 29A, and the ball return passage 9 is exposed on the thin plate portion 29A.

The first resin-formed frame 20A and the second resin-formed frame 20B are connected, as shown in Figure 9, by a joining method which employs the combination of a cavity and a protrusion to be inserted therein, as a method. of junction to tap. In the illustrated example, a recess portion 36 of a dovetail groove is formed on the second resin-formed frame 20b and an engaging projection 35 to be engaged with the recess portion 36 is formed, on the other hand, in the ball passage forming portions 21, 21.

In this case, the resin tube 23 of the first resin-formed frame 20A is inserted into the through hole 14 of the block body 13, and the first, second and third portions a. connecting plate 25, 26, 27 are inserted along the lower surface of the horizontal portion 6 of the block body 13 and the internal surfaces of the wing portions 7, 7.

Then, the engaging projections 35 formed on the respective free end portions of the first, second and third connecting plate portions 25, 26, 27 are engaged with the recess portions 36 formed on the thin plate portion 29B of the second frame formed. resin 24B, which is arranged on the other end surface of the block body 13.

The recess portions 36 can be formed on the first resin-formed frame 20A and the engaging projections 35 can be formed on the second resin-formed frame 20B. The connection method is not limited to the method described above, and any conventional connection method can be employed, in which the ends of the split parts can be held in an appropriate connection position and connected.

[Second modification]

Figures 10 and 11 show the second modification of the resin-formed body 20 to form the ball circulation passage, which is described in the first embodiment.

In the second embodiment, the resin-formed body 20 for forming the ball circulation passage, which was obtained by integrally forming the two ball passage-forming portions 21, 21 and the resin tubes 23 as the ball passage-forming portion 21, 21. return with a pair of inner guide forming portions 22, 22 of change of direction passage, is divided in the central portion of each of the ball passage forming portions 21, 21 and resin tubes 23, into two parts. More specifically, the ball passage forming portions 21, 21 and the resin tubes 23 are divided in their central portion into two respective halves, and each of the two halves thus divided is integrally formed with the portions 22, 22 of internal guide formation of change of direction passage, thus forming two resin formed frames 20C, 20D having substantially the same shape.

Four sets of the ball passage forming portions 21, 21 are formed in the first, second and third connecting plate portions 25, 26, 27. Recess portions 38 and engaging projections 37 to be inserted therein are formed on the split ends of the first, second and third connecting plate portions 25, 26, 27 and on the split ends of the resin tubes 23.

[Third modification]

Figures 12 through 14 show the third modification of the resin-formed body 20 to form the ball circulation passage, which is described in the first embodiment.

In the third modification, the resin tube 23 is not employed as the forming portion of. return passage described in the first embodiment, and a resin-formed frame 20E is obtained by integrally forming the first, second and third connecting plate portions 25, 26, 27 having the ball passage forming portions 21, 21 with the thin plate portions 29, 29 each having the pair of inner guide forming portions 22, 22 of change of direction passage. The ball return passage 9 is composed of a through hole formed in the block body 13.

In this case, an engaging projection 39a which is engageable with a tapered portion 15 formed in the opening end of the ball return passage 9 can be formed in the opening end of the ball hole 39 of the thin plate portion 29. structure allows proper connection of the end of the ball return passage 9 and the inner guide forming portion 22 of the change of direction passage.

In the illustrated example, an arcuate engaging projection 48 is additionally formed in the connecting portion of the outer guide groove 10b for the change of direction passage with the ball return passage 9. The engaging projection 48 can be fitted into the ball hole 39 of the thin plate portion 29 engaged with the tapered portion 15 of the opening end of the ball return passage 9.

(Fourth modification]

Figure 25 shows the fourth modification of the resin-formed body 20 to form the ball circulation passage which is described in the first embodiment.

In the fourth embodiment, the resin tube 23 described in the third modification is not used, a resin-formed frame 24B is obtained by integrally forming the ball passage forming portions 21 with the inner passage guide forming portions 22. direction change for one side, the other resin-formed frame 24C equipped with internal guide-forming portions 22 of the direction-change passage for the other side is formed separately from the aforementioned resin-formed frame 24B and the resin formed frames 24B and 24C are connected to each other by engagement of the engaging projection 35 with the recess 36. The structure other than the aforementioned structure is the same as that of the third modification.

(Modifications of the train of balls]

In the first embodiment and in the first to fourth modification, it is disclosed that two sets of balls are provided in the upper surface of the guide rail 2 and a single train of balls is provided on each of the lateral surfaces of the guide rail 2, so as to procure the total number of trains of four. In the present invention, the other type of ball train can however be applied as shown in FIG. 16. With respect to splitting the resin-formed body 20 to form the ball circulation passage, all modifications as shown in FIG. 16 are based on the division model of the first implementation. All the division patterns of the first through the fourth modification can however be applied to the modifications of the ball train as shown in figure 16.

In the example as shown in Figures 16 (a) and 16 (b) two lower and upper trains of the balls as rolling elements are provided on each of the interspaces between the right and left side surfaces of the guide rail 2 and the inner surfaces of the right and left wing portions 7, 7 of the movable block 13, so as to provide the total number of trains of four.

Figure 16 (b) shows a resin-formed body 20 in which the ball passage forming portions for the four ball trains are integrally formed with each other. The resin-formed body 20 can however be divided into two resin-formed bodies 20, 20, which correspond to two trains of balls for each of the right and left sides of the guide rail 2, as shown in Figure 18.

In the example, as shown in Figures 16 (c) and 16 (d), the movable block 4 is provided with the horizontal portion 6 which faces the upper surface of the guide rail 2 and the single wing portion 7 which faces green. lateral surface of the guide rail 2. The single train of the balls 3 as rolling elements is provided between one side surface of the guide rail 2 and the single wing portion 7 of the movable block 4, and the other single train of the balls 3 is provided between the upper surface of the guide rail 2 and the lower surface of the horizontal portion near the corner of the guide rail 2, so as to provide the total number of trains of two.

In the example shown in Figures 16 (e) and 16 (f), the mobile block 4 is provided with a pair of wing portions 7, 7 between which the guide rail 2 is held in its right and left surfaces. The single train of balls 3 is procured in each of the interspaces between the left and right surfaces of the guide rail 2 and the inner surfaces of the left and right wing portions 7,7 of the movable block 4, so as to provide the total number of trains of two.

In the example as shown in Figures 16 (g) and 16 (h), the movable block 4 is arranged along a lateral surface of the guide rail 2. The two upper and lower trains of the balls 3 are provided between a lateral surface of the rail guide 2 and the mobile block 4.

[Second realization]

Figures 18 through 20 show a linear motion guiding apparatus of the second embodiment of the present invention.

In the second embodiment, rollers are used as rolling elements. More specifically, the linear motion guide apparatus comprises a guide rail 202 as a guide element, which extends linearly, and a movable block 204 arranged to be movable along the guide rail 202 through a large number of rollers. 203 as rolling elements.

Guide rail 202 is formed in a long bar shape having a rectangular cross section. Two roller running surfaces 205, 205 as a rolling element running track are formed on the horizontal upper surface of the guide rail 2 and a single roller running surface 205 as a rolling element running track is formed on each of the right and left vertical surfaces of the guide rail 2, so as to provide a total number of surfaces 5 of four.

The movable block 204 is formed as a block body having an inverse U-shaped cross section, with its opening directed downward. The block body is provided with a horizontal portion 206 which faces the upper surface of the guide rail 202 and with a pair of wing portions 207, 207, which extend downwardly from the right and left ends to the horizontal portion 206 and face the left and right side surfaces of guide rail 202, respectively. The horizontal portion 206 has on its lower surface two roller running counter surfaces 208, 208 as a rolling element counter race which correspond to the roller running surfaces 205, 205 formed on the upper surface of the guide rail 202. Each of the wing 207, 207 has on its inner surface a single roller running counter surface 208 as a rolling element counter running track, which corresponds to the respective roller running surfaces 205, 205 formed on the right and left side surfaces of the guide rail 202.

In addition, four roller return passages 209, 209, 209, 209 are formed in the movable block 104 as a rolling element return passage which are provided parallel to the four counter surfaces 208, 208, 208, 208 of roller travel, respectively, as well as four pairs of change-of-direction passages 210, 210, 210, 210, each having a U-shape, for connecting the respective ends of the counter surfaces 208, 208, 208, 208 to the two respective ends of the rollers. roll return passages 209, 209, 209, 209, so as to form four endless circulation passages.

The roller return passages 209, 209 respectively corresponding to the roller running surfaces 205, 205 formed on the upper side of the guide rail 202 are formed in the horizontal portion 206. The other roller return passages 209, 209 respectively corresponding to the surfaces Rollers 205, 205 formed on the right and left vertical surfaces of the guide rail 202 are formed in the wing portions 207, 207 of the movable block 204, respectively.

In each of the endless circulation passages in this embodiment, the rollers, the rollers 3 are held in the train form by a roller retainer 212 as a rolling element retainer so that the rollers 203 can be circulated while they are guided by the roller retainer 212.

As shown in Figures 19 (b) through 19 (d), the roller retaining device 212 comprises a flexible belt portion 212b, which is provided with two roller holes 212a to collect the rollers 203, respectively, and spacer portions 212a provided between two adjacent rolls 203, 203. The belt portion 212b has a width greater than the diameter of the roller 203 so that both side edges of the belt portion 212 extend outwardly from the roller 203.

The spacer portion 212c is provided with cavities 212b of a roller support corresponding to the cylindrical surface of the roller 203. The roller 203 is supported on its two sides by a pair of support cavities 212d so as to prevent the roller 203 from coming off the belt portion 212b. In this embodiment, one end of the ribbon portion 212d is not connected to the other end thereof, thus forming a strip-shaped ribbon having both ends. One end of the ribbon portion 212b may be connected to the other end thereof to form an endless ribbon.

As shown in Figures 19 and 20, the movable block 204 is composed of a block body, metal 213 having counter surfaces 208, 208, 208, 208 for running the rollers, a body formed of resin 220 to form circulation passages of rollers which is inserted into the block body 213, and a pair of side cover plates 214, 214 fixed to the two end surfaces of the block body 213, into which the resin-formed body 220 is inserted. In the second embodiment, they are formed four circulation passages by means of two bodies formed of resin 220, 220, to form the circulation passage of rollers, which are arranged on the right and left sides.

Each of the roller circulation passages of the resin formed bodies 220 comprises a pair of roller passage forming portions 221, 221 extending along the two longitudinal sides of the roller course counter surface 208, a pair of roller course forming portions 221, 221 internal direction change passage guide 222, 222 provided on the two side surfaces of the block body 213, and a resin tube 223 as a return passage forming portion, which is inserted into a through hole formed in the block body 213 .

The roller passage forming portions 221, 221 are provided with guiding surfaces for guiding the two side edges of the belt portion 212b of the roller retainer 212 into a loaded area as detailed in FIG. 20. Guide grooves can prevent the roller retainer 212 from not only oscillating during the travel of the roller, but also from flexing by engaging the side edges of the belt portion 212b with the guide groove 221a. Rollers 203 are supported by roll retainer 212. More specifically, the roller retainer 112. More specifically, the roll reigning device 212 is supported by a jaw portion of the guide groove 221a, with the result that the rollers 203 are held in their proper position so as not to come off the movable block 204.

In this embodiment, one end of the ribbon portion 212b is not connected to the other end thereof thus forming a strip-shaped ribbon having the two ends. One end of the ribbon portion 212b can be connected to the other end thereof to form an endless ribbon.

Guide grooves 209c, 210c are also formed in the roll return passage 209 and direction change passage 210 as unloaded areas, in order to guide the side edges of the belt portion 212b. The guide grooves 209c, 219c are connected to the aforementioned guide groove 221a in the loaded area, so as to form an endless groove over the entire periphery.

In each of the formed resin bodies 220, 220 to form the roller circulation passage, the roller passage forming portions 221, 221 and the pair of the change-of-direction internal guide forming portions 222, 222 are formed integrally with each other. The resin tube 223 for forming the roll return passage 209 is formed separately from the resin formed bodies 220, 220. More specifically, the one ends of the two pairs of the roller passage forming portions 221, 221 are integrally connected with the ends of the pair of change-of-direction inner guide forming portions 222, 222-, to form a single resin frame 220a so that the resin frame 220a thus formed can be inserted into the block body 213. L other 220a resin frame has the same structure.

The roller passage forming portions 221, 221 to be arranged on the upper surface of the guide rail 202 are integrally connected with the other roller passage forming portions 221, 221 to be arranged on the lateral surface of the guide rail 202 by a portion with thin connection plate 226.

The change-of-direction inner guide forming portion 222 is integrally formed with a thin plate portion 229, which is to be brought into contact with the end surface of the block body 213.

The thin plate portion 229 has the first terminal plate portion 230, which is to be brought into contact with the end surface of the horizontal portion 206 of the block body 213, the third terminal plate portion 232 which is to be brought into contact with the end surface of the wing portion 207, and the second end plate portion 231, which is disposed in the corner between the horizontal portion 206 and the wing portion 207 on the end surface of the block body 213 and connects the first portion end plate 230 with the third end plate portion 232.

The pair of roller passage forming portions 221, 221, which are arranged on the two longitudinal sides of the roller running surface 208, are integrally formed on the inner edge of the first end plate portion 230 and on the inner edge of the third plate portion terminal 232, respectively. The two ends of the connecting plate portion 226 are integrally connected in the inner edges of the second plate portions 231, 231.

Each of the inner guide forming portions of change-of-direction passage has a semi-cylindrical shape. On the outer periphery of the inner guide forming portion 222 of the change of direction passage, an inner guide groove 210a having a rectangular cross section so as to form the inner guide portion for the change of direction passage 210 is formed. The one end of the bottom of the inner guide groove 210a is connected to the end of the roller running counter surface 208. Accordingly, the one end of the inner guide groove 210a has the same cross-sectional shape as the roller running counter surface 208 so as to provide an alignment of the one end of the inner guide groove 210a with the end of the counter surface 208. of run of rollers. The other end of the inner guide groove 210a of the change of direction passage 210 is connected to the end of the roller return passage 229. Accordingly, the other end of the inner guide groove 210 is of the same cross-sectional shape as the roller return passage 209, thereby providing an alignment of the other end of the inner guide groove 210a with the end of the roll return passage 209.

Cylindrical flange portions 233, 233 are formed on the two ends of the inner guide groove 210a. The distance between the respective outer surfaces of the cylindrical flange portions 233, 233 is greater than the width of the belt portion 212b. The cylindrical flange portions 233, 233 form a guide groove 210c for the roller retainer 212 in cooperation with the side cover plate 240 described later.

One end of the inner guide groove 210 for the direction change passage 210 extends to the contact surface of the first and third end plate portions 230, 232 with the end surface of the block body 213, so as to be connected to the end surface of the block body 213. end of the counter-surface 208 for the running of the rollers. The other end of the inner guide groove 210a for the change of direction passage 210 extends to the end surface of the thin plate portion 229, which is remote from the block body 213. A stepped portion 222a having an identical depth to the thickness of the thin plate portion 229 is formed in the other end of the inner guide groove 210a. The inner peripheral side half tubular element of the resin tube 223 projects from the end surface of the block body 13 by a length identical to the thickness of the plate portion 229. The protruding end of the tubular half element 223a is adapted to the portion a step 222a of the thin plate portion 229.

Tube insertion holes 234, 234 having a semicircular shape, into which the ends of the outer peripheral lateral half tubular element 223a are to be inserted for the resin tubes 223 to form the roll return passage 209, are formed on the former and third terminal plate portions 230, 232 of the terminal thin plate portion 229. The resin tube 223 is inserted into the circular through hole 214 formed in the block body 213 so that the inner peripheral surface of the resin tube 223 forms the passage 229 return of rollers.

As shown in Figure 20, the resin tube 223 is composed of the inner peripheral side half tubular element 223a which is continuously connected to the inner guide groove 210a for the change of direction passage, and the lateral half tubular element outer peripheral 223b, which is connected continuously to the outer guide groove for the change of direction passage 210, which is formed on the side cover plate 240: The inner peripheral side half tubular element 223a has an inner groove portion 209a having a rectangular cross section and side edge portions 223b extending longitudinally along the inner groove portion 209a. The longitudinal edge portions 223c of the inner peripheral side half tubular member 223a have the same width as the flange portion 233 of the portion 228.

The outer peripheral side half tubular element 223b is formed into a linear element having the same rectangular cross section as the outer guide groove 210b for the change of direction passage, which is formed on the side cover plate 240. The element outer peripheral side half tubular 223b has an outer groove portion 209b, which is continuously connected to the outer guide groove 210b, and side edge portions 223d extending longitudinally along the outer groove portion 209b. The lateral edge portions 223d are provided on their outer edges with protrusions 223e which are to be brought into contact with the lateral edge portions 223c of the inner peripheral lateral half tubular element 223a, to form the guide groove for the belt portion 212 of the roll retaining device 212.

The inner peripheral side half tubular element 223a of the resin tube 223 is the same length as the block body 213. The inner peripheral side half tubular element 223a is positioned to be brought into contact with the end surface of the change-of-direction inner guide forming portion 222 which is disposed on the side of the lock body 213.

The outer peripheral lateral half tubular element 223b of the resin tube 223 on the other hand has a greater length than the block body 213 by an amount corresponding to the thickness of the first and third end plate portions of the thin plate portion 229, which are arranged at the two ends of the block body 213. The outer peripheral lateral half tubular elements 223b are inserted into the insertion holes 234 of the first and third end plate portions 230, 232. Determining the longitudinal position of the tubular half element outer peripheral side 223b is made by bringing the two ends of the outer peripheral side half tubular element 223b inserted into the insertion holes 234 in contact with the peripheral edge of the end portion of the outer guide grooves 210b for the change of direction passage, which are formed on the side cover plate 240. The projections 223e formed on the two edges later longitudinal wings 223 of the outer peripheral lateral half tubular member 223b contact the cylindrical flange portions 233- in the lateral edges of the inner guide groove 210a of the inner guide forming portion 222 of change-of-direction passage, and the The outer peripheral side half tubular member 223b and the inner peripheral side half tubular member 223a are limited to being turned into the insertion hole 214.

The resin tubes 223 and the change-of-direction inner guide forming portions 222 are precisely positioned through the through holes 234 formed on the first and third end plate portions 230, 232 of the thin plate portion 229 and comes into this way carried out an appropriate assembly.

The side cover plate 240 is provided with four recess portions 241 having the outer guide grooves 210b for the change-of-direction passage, in which the parts 228 of the inner guide-forming portions of the change-of-direction passage 222 are fitted , and of screw fixing portions for securing the side cover plate 240 to the block body 213. In the screw fixing portions, the side cover plate 240 is fixed to the block body 213 by inserting the bolts 244 holes 243 formed on the side cover plate and engagement of the bolts 244 with threaded holes 545 formed on the end surface of the block body 213. The holes 243 are located between the first and third end plate portions 230, 232 of the thin plate portion 229.

The inner guide forming portion of the change of direction passage 222 provided with the inner guide groove 210a for the change of direction passage is adapted in the recessed portion 241 of the side cover plate 240. The thin plate portion 229 is retained between the side cover plate 240 and the end surface of the lock body 213 through a clamping force so as to be firmly fixed therebetween.

The change-of-direction inner guide forming portions 222 and the roll passage forming portion 221 are connected through the thin plate portion 229, thus making it possible to maintain an accurate position relationship of the end of the inner guide groove 210a for the direction change passage relative to the roll passage forming portions 221, as well as a precise position relationship of the inner guide groove 210a for the direction change passage relative to the roll return passage 209.

The thin plate portion 229 is pushed uniformly against the flat end surface of the lock body 213 through a clamping force applied to the side cover plate 240. Even when the change-of-direction inner guide forming portion 222 is not is located in a correct position, the thin plate portion 229 changes its shape, thus permitting the correct positioning of the inner guide forming portion of the change of direction 222. The thin plate portion 229 is firmly clamped and secured through a clamping stroke, which is applied to the side cover plate 240, and a friction force determined by that clamping stage can prevent unfavorable movement of the inner guide groove 210a for the change of direction passage.

Modifications of the resin-formed body 220 to form the roller circulation passage, which is divided into two parts, will be described. In the description of the modifications, modified features will be illustrated only in comparison with the second embodiment of the present invention. The same reference numbers will be given to the same components as those in the second embodiment of the present invention, and their description will be left out.

[First modification]

Figures 21 and 22 show the first modification of a resin-formed body 20 to form the ball circulation passage, which is described in the second embodiment.

In the first modification, the resin-formed body 220 to form the ball circulation passage is composed of the first resin-formed frame 220A, which is obtained by integrally connecting both of the roller and tube passage-forming portions 221, 221. of resin 223 at their ends with the change direction inner guide forming portions 222A for one side, and the second resin formed frame 220B, which is provided with the change step inner guide forming portions 222B for the other side, and formed separately from the first resin forming frame 320a.

In this case, the roll passage forming portion 221, 221 are integrally connected with the change direction passage inner guide forming portions 222A through the thin plate portion 229A, as in the second embodiment.

The change-of-direction inner guide forming portions 222 are also integrally connected with the resin tubes 223 through a thin plate portion 229A. In this case, resin tube 223 is formed in an integral tubular body, although semitubular elements are employed in the second embodiment. Consequently, there is no insertion hole 234 in the thin plate portion 229A and the return roller passage 209 is exposed on the thin plate portion 229A.

The first resin-formed frame 20A and the second resin-formed frame 220b are connected, as shown in Figure 22, using a joining method that uses the combination of a cavity and a protrusion to be inserted, such as a cap joining method. In the illustrated example, a cavity portion 23 of a dovetail groove is formed in the second resin-forming frame 220B and an engaging projection 235 is formed to engage with the cavity portion 236, on the other hand, in the portions 221, 221 of roller passage formation.

In this case, the resin tube 223 of the first resin-formed frame 220A is inserted into the through hole 214 of the block body 213, and the roller passage forming portions 221, 221 and the connecting plate portions 226 they are inserted along the lower surface of the horizontal portion 206 of the block body 213 and along the internal surfaces of the wing portions 207, 207.

Then, the engaging portions 235 formed in the roller passage forming forming portions 221, 221 and the connecting plate portion 226 are engaged with the cavity portions 236 formed on the thin plate portion 229B of the second frame formed. -resin 224b, which is disposed on the other end surface of the block body 213.

The cavity portions 236 can be formed on the first resin formed frame 220A and the engaging projections 235 can be formed on the second resin formed frame 220B. The connection method is not limited to the method described above, and any conventional connection method can be employed in which the ends of the split parts can be held in an appropriate connection position and connected.

(Second modification]

Figures 23 and 24 show the second modification of the resin-formed body 220 to form the ball circulation passage, which is described in the second embodiment.

In the second modification, the resin-formed body 220 to form the roller circulation passage which has been obtained by integrally forming both of the roller passage-forming portions 221, 221 and the resin tubes 223 as the return passage-forming portion 221, 221. with a pair of change-of-direction inner guide forming portions 222, 222, it is divided in the central part of each of the roller passage forming portions 221, 221 and resin tubes 223, into two parts. More specifically, the roller passage forming portions 221, 221 and the resin tubes 223 are divided in their central part into the two respective half-parts, and each of the two half-parts thus divided is integrally formed with the internal guide portions for the passage of change of direction 222, 222, thus forming two formed frames of resin 220C, 220D, having substantially the same shape.

Cavity portions 238 and engaging projections 237 to be inserted therein are formed on the split ends of the roller passage forming portions 221, 221 and on the split ends of the connecting plate portion 226 and on the split ends of the resin tubes 223.

[Third modification]

Figures 25 to 26 show the third modification of the resin-formed body 220 to form the roller circulation passage, which is described in the second embodiment.

In the third modification, the resin tube 223 is not employed as the return passage forming portion described in the second embodiment, and the resin formed frame 220E is obtained by integrally forming both roller passage forming portions, and the connecting plate portion 226 with the thin plate portions 229, 229 each having the pair of change direction passage inner guide forming portions 222, 222. The roller return passage 309 is composed as a through hole formed in the block body 213.

In this case, an engaging projection 239a, which is engageable with a tapered portion 215 formed in the opening end of the roller return passage 209, may be formed in the opening end of the roller hole 239 of the thin plate portion 229. Such a structure permits proper connection of the end of the roller return passage 209 and the inner guide forming portion of the change-of-direction passage, 222.

In the illustrated example, an arcuate engaging projection 248 is additionally formed on the connecting portion of the inner guide groove 210b for the change of direction passage with the return roller passage 209. The engaging projection 248 may be fitted into the roller hole 239 of the thin plate portion 229 engaged with the tapered portion 215 of the opening end of the roller return passage 209.

[Fourth modification]

Fig. 26 shows the fourth modification of the resin-formed body 220 for forming the roller circulation passage, which is described in the second embodiment.

In the fourth modification, the resin tube 223 described in the third modification is not employed, a resin formed frame 220F is obtained by integrally forming the roller passage forming portions 221 with the change passage inner guide forming portions. 222 for the one side, the other resin-formed frame 220F provided with the change-of-direction inner guide forming portions 222 for the other is formed separately from the aforementioned resin-formed frame 320F, and the resin formed frames 220F, 220F are connected to each other by engagement of the engaging projection 235 with the cavity 236. The structure in addition to the aforementioned construction is the same as that of the third modification.

[Modifications of the roller train]

In the second embodiment and in the first and fourth modifications, it is described that two sets of rollers are provided on the upper surface of the guide rail 2 and a single train of rollers is provided on each of the lateral surfaces of the guide rail 2, so as to provide the total number of trains of four. In the present invention, the other type of roll trains can however be applied as shown in the figures. With respect to splitting the resin-formed body 220 to form the roll circulation passage, all modifications are based on the split pattern of the first embodiment. All split patterns of the first through fourth modification can however be applied to the roll train modifications.

In the example as shown in Figure 27, two lower and upper trains of the rollers as rolling elements are provided on each of the gaps between the left and right side surfaces of the guide rail 202 and the inner surfaces of the right and left wing portions 207 , 207 of the mobile block 204, so as to provide the total number of trains of four.

In this case, four internal guide portions 210a corresponding to the four trains of rollers 203 are integrally formed with each other in the change-of-direction passage internal guide forming portions 222.

In the above description, the present invention is applied to linear motion guide apparatus, wherein the movable block is disposed on the guide rail as a shaft running through rolling element. The present invention can however be applied to a so-called ball spline unit in which an outer tube as a movable member is fitted on a spline shaft as a stroke shaft, as described below.

[Third realization]

A ball spline unit 301 as shown in Figures 28 to 30 is a so-called "angular contact" ball spline unit and has a spline shaft 302 as a linearly extending guide member and an outer tube 304 arranged so as to be movable along the spline shaft 302 through balls 303 such as a large number of rolling elements.

The spline shaft 304 is shaped into a long bar shape having a circular cross section. The spline shaft 304 has on its outer periphery three protrusions 306. Two ball race grooves 305, 305 are formed on the two sides of the protrusions 306, so as to provide the total number of grooves of six.

The outer tube 304 has on its inner periphery three recesses 307 corresponding to the projections 306 of the spline shaft 302, respectively. Counter ball run grooves 308, 308 are formed at the two corners of each of the recesses 307 to correspond to the aforementioned ball run grooves 305, 305.

In addition, the outer tube 204 has six passages 309, 309; 309, 309; 309, 309 of ball return which are parallel with the six counter grooves 308, 308; 308, 308; 308, 308 of run of balls and six steps of change of direction 310, 310; 310, 310; 310, 310 formed in a U-shaped tube, which connect the ends of the aforementioned counter-grooves 308, 308; 308, 308; 308, 308 of running balls as ends of the aforementioned passages 309, 309; 309, 309; 309, 309 of return balls. The outer tube 304 has six circulation passages in this manner. The ball disposed in each of the two side surfaces of the protrusion 306 of the spline shaft 302 contacts at the opposite points, the ball race groove 305 and the ball race counter groove 308, respectively. A line connecting the aforementioned contact points is referred to as a "contact angle line". A contact angle a, i.e. an angle between the contact angle line and the radius line, which connects the center of the spline shaft 302 and the central portion of the projection 306 is relatively large. The ball return passage 309 is located on the contact angle line.

In this third embodiment, the balls 303 inserted into each of the circulation passages are connected to each other by a ball retaining device 312 to form a train of balls 303. The balls 303 are guided by the device ball retainer 312 and circulated in each of the circulation passages. The ball retaining device 312 has the same structure as shown in Figure 14 and a description thereof will therefore be omitted.

The outer tube 304 is composed of a tubular main body 313 having counter-grooves 308, 308; 308, 308; 308, 308 of run of balls, by three bodies formed of resin 320, 320, 320 to form the passage of circulation of balls which are inserted in the main body 313 and by a pair of side cover plates 314, 314 secured at both ends of the main body 313 after the insertion of the formed bodies of resin 320, 320, 320 into the main body 313.

In the third embodiment, the six circulation passages are formed by the three resin formed bodies 320, 320, 320.

Each of the circulation passages 311 of the resin formed bodies 320 to form the ball circulation passage has a pair of ball passage forming portions 321, 321 extending along the longitudinal side edges of the ball run counter-groove 308, a pair of change-of-direction inner passage guide forming portions 322, 322 provided at the two ends of the main body 313, and resin tubes 323 as the return passage forming portion, which are inserted into through holes formed in the body main 313.

The ball passage portions 321, 321 are provided with guide grooves for guiding the two side edges of the belt portion 312b of the ball retainer 312 into a loaded area. The guide grooves can prevent the ball retainer 312 from not only swinging during the travel of the ball, but also from deflecting by engagement of the side edges of the belt portion 312b with the guide groove 321a, when the outer tube 304 it is removed from the spline shaft 302. The balls 303 are supported by the retainer. 312 of sphere. More specifically, the ball retainer 312 is supported by a jaw portion of the guide groove 321a, with the result that the balls 303 are held in their own position so as not to come out of the guide tube 304.

Guide grooves 309c, 310c are also formed in the ball return passage 309 and the direction change passage 310 as unloaded areas, in order to guide the side edges of the belt portion 312b. The guide grooves 309c, 310c are connected to the aforementioned guide grooves 321a in the loaded area so as to form an endless groove over the entire periphery.

In each of the resin formed bodies 320 to form the ball circulation passage, the ball passage forming portions 321, 321 and the pair of the change direction passage inner guide forming portions 322, 322 are integrally connected the one with the other. The resin formed body 320 is divided into the other portions into separate parts so as to be capable of being inserted into the main body 313. In the third embodiment, a single resin frame 324 is obtained by integrally connecting the ends of the four sets of portions 321 Ball passage forming portion 321 with the end of the pair of change direction passage inner guide forming portions 322, 322, and the resin frame 324 thus obtained is divided into the connecting portion of the passage forming portion return path 323 with the change-of-direction inner guide forming portions 322, 322, in separate parts so as to be able to be inserted into the main body 313.

The two adjacent roll passage forming portions 321, 321, 321, 321 are integrally connected to each other by a connecting thin plate portion 326. The change-of-direction inner guide forming portion 322 is integrally formed with the thin plate portion 329 which is to be brought into contact with the end surface of the main body 313.

The thin plate portion 329 is provided with the first end plate portions 330, 330 and the second end plate portion 231 for connecting the first end plate portions 330, 330 to each other. Each of the pair of ball passage forming portions 321, 321 is integrally connected with the inner edge of the first end plate portion 230. Both ends of the connecting plate portion 326 are integrally connected with the inner edge of the second end plate portion 326. end plate 331.

Each of the change-of-direction inner guide forming portions 322 has a semicircular shape. A guide groove 310a having a semicircular cross section is formed on the outer periphery of the inner guide forming portion of the change of direction passage 322 to form the inner guide portion for the change of direction passage 310. The one end of the inner guide groove 310a is connected to the end of the ball run counter groove 308. Accordingly, the one end of the inner guide groove 310a has the same cross-sectional shape as the ball run counter groove 308 so as to provide an alignment of the one end of the inner guide groove 310a with the end of the counter groove 308. of running balls. The other end of the inner guide groove 310a of the change of direction passage 310 is connected to the end of the ball return passage 309. Accordingly, the other end of the inner guide groove 310a has the same cross-sectional shape as the ball return passage 309 so as to provide an alignment of the other end of the inner guide groove 310a with the end of the passage. 309 of return spheres.

The cylindrical flange portions 333, 333 are formed at both ends of the inner guide groove 310a. The distance between the respective outer surfaces of the cylindrical flange portions 333, 333 is greater than the width of the belt portion 312b. The cylindrical flange portions 333, 333 form a retaining device guide groove 310c for the ball retaining device 312 in cooperation with the side cover plate 340 described later.

The two ends of the inner guide groove 310a for the direction change passage 310 extend to the contact surface of the first end plate portion 330 with the end surface of the main body 313 so as to be connected to the respective ends of the counter-groove 308 of the ball race and of the ball return passage 309.

Tube insertion holes 334, 334 having a semicircular shape, into which the ends of the outer peripheral side half tubular element 323a for the resin tubes 323 to form the roll return passage 309 are to be inserted, are formed on the former and third end plate portions 330, 332, of the thin plate portion 329. The resin tube 323 is inserted into the circular through hole 314 formed in the main body 313 so that the inner peripheral surface of the resin tube 323 forms the passage 309 return of the rollers.

The resin tube 323 is composed of the inner peripheral side half tubular member 323a which is continuously connected to the inner guide groove 310a for the change of direction passage, and the outer peripheral side half tubular member 313b, which is continuously connected to the outer guide groove 310b for the direction change passage 310, which is formed on the side cover plate 340. The inner peripheral side half tubular member 323a has an inner groove portion 309a having a rectangular cross section , and the side edge portions 323b extending longitudinally along the inner groove portion 309a. The longitudinal edge portions 323c of the inner peripheral side half tubular element 323a have the same width as the flange portion 333 of the change-of-direction inner guide forming portion 322.

The outer peripheral side half tubular element 323b is formed into a linear element having the same rectangular cross section as the outer guide groove 310b for the change of direction passage, which is formed on the side cover plate 340. The element outer peripheral side half tubular 323b has an outer groove portion 309b which is continuously connected to the outer guide groove 310b, and lateral edge portions 323d extending longitudinally along the outer groove portion 309b. The lateral edge portions 323d are provided in their outer edges with protrusions 323e, and are to be brought into contact with the lateral edge portions 323c of the inner peripheral lateral half tubular element 323a to form the guide groove for the belt portion 312 of the ball retaining device 312.

The inner peripheral side half tubular element 323a of the resin tube 323 is the same length as the main body 313. The inner peripheral side half tubular element 323a is positioned to be brought into contact with the end surface of the change-of-direction inner guide formation 322, which is arranged on the side of the main body 313.

The outer peripheral lateral half tubular element 323b of the resin tube 323 on the other hand has a greater length than the main body 313 by an amount corresponding to the thickness of the first end plate portions 330, 330 of the thin plate portion 329, which are disposed on both ends of the main body 313. The outer peripheral side half tubular elements 323b are inserted into the insertion holes 334 of the first end plate portions 330, 332. Determining the position of the outer peripheral side half tubular element 323b is made by bringing the two ends of the outer peripheral side half tubular element 323b inserted into the insertion holes 334 into contact with the peripheral edge of the end portion of the outer guide grooves 310b for the change of direction passage, which are formed on the cover plate 340. The projections 323e formed on both side edges longitudinally wings 323 of the outer peripheral side half tubular element 323b contact the outer edges of the cylindrical flange portions of the change-of-direction inner guide forming portion 322 to form a guide groove, and the tubular element outer peripheral side half 323b and the inner peripheral side half tubular member 323a are limited to being turned into the insertion hole 314.

The resin tubes 323 and the change of direction inner guide forming portions 322 such as the ball return passage forming portions are precisely positioned through the insertion holes 334 formed on the first end plate portion 330, 330 of the thin plate portion 319 and appropriate assembly is made in this manner.

The side cover plate 340 is provided with four recess portions 341 having the outer guide grooves 310b for the change-of-direction passage, in which the inner guide-forming portions of the change-of-direction passage 322, and of screw fixing portions for securing the side cover plate 340 to the main body 313. In the screw fixing portions, the side cover plate 340 is fixed to the main body 313 by inserting bolts 344 into holes 343 formed on the cover plate 340 and engaging the bolts 344 with the threaded holes 345 formed on the end surface of the main body 313. The holes 343 are located between the first end plate portions 330, 330, of the thin plate portion 329.

The change-of-direction inner guide forming portion 322 is fitted into the recess portion of the side cover plate 340. The thin plate portion 329 is held between the side cover plate 340 and the end surface of the main body 313 through a clamping force so as to be firmly fixed between them.

The change-of-direction inner guide forming portions 322 and the ball pass-forming portion 321 are connected through the first thin plate portion 329, thus making it possible to maintain an accurate position relationship of the end of the guide groove internal guide groove 310a for the direction change passage relative to the ball passage forming portions 321, as well as a precise position relationship of the internal guide groove 310a for the direction change passage relative to the ball return passage 309.

The thin plate portion 329 is uniformly pushed against the flat end surface of the main body 313 through a clamping force applied to the side cover plate 340. Even when the change-of-direction inner guide forming portion 322 is not located in a correct position, the thin plate portion 329 changes its shape, thereby allowing correct positioning of the inner guide forming portion of the change of direction 322. The thin plate portion 329 is firmly clamped and fixed by a force of clamping, which is applied to the cover plate 340, and a frictional force determined by that clamping stage can prevent an unfavorable movement of the inner guide groove 310a for the change of direction passage.

According to the present invention, only against the ball run groove 308 for the circulation passage 311 is formed by the main body 313 having a high rigidity, and the other portions are formed by the resin formed bodies 320 to form the circulation passage of spheres. A precision machining of the ball run counter-groove 308 of the main body 313 is sufficient, thus allowing a reduction of machining steps and a decrease in the cost of production.

The resin formed body 320 to form the ball circulation passage is formed separately from the main body 313. Even when the outer tube 304 is larger in size, there is no flow restriction of the molten resin by the body 313, unlike from the case where the main body 313 is integrally formed with the formed body of resin 320. An increase in the number of casting attachments formed on a mold can ensure proper flow of the molten resin, thereby improving formability. Especially, the ball passage forming portions 321, 321 located on opposite longitudinal sides of the ball run groove 308 are thin, with the result that the molten resin may not reach every part of the space to form the portions 321, 321 of formation of passage of spheres. It is therefore effective to form the resin formed body 320 separately from the main body 313 in accordance with the embodiment of the present invention.

The ball passage forming portions 321, 321 are continuously integrally connected with the change direction passage inner guide forming portions 322, and the divided parts are joined to provide an alignment thereof to make a plug joint. . It is therefore possible to ensure proper continuity of the connecting portion of the circulation passage and to provide a smooth run of the balls 303 from the ball run passage between the ball run groove 305 and the ball run counter-groove 308 to the ball run passage 310 change of direction, as well as from the change of direction passage 310 to the ball return passage 309.

A description will be made of modifications of the resin formed body 320 to form the ball circulation passage, which is divided into two parts. In the description of the modifications, modified features will only be illustrated in comparison with the third embodiment of the present invention. The same reference numbers will be attributed to the same components as those in the third embodiment of the present invention, and a description thereof will be left out.

[First modification]

Figures 31 and 32 show the first modification of the formed resin body 320 to form the ball circulation passage, which is described in the third embodiment.

In the first modification, the resin formed body 320 to form the ball circulation passage is composed of the first resin frame 320A which is obtained by integrally connecting both of the ball passage forming portions 321, 321 and the resin tubes 323 at their ends with the change of direction inner guide forming portions 322A for one side, and the second resin formed frame 320B which is provided with change of direction inner guide forming portions 322B for the other side, and separately formed by the first frame formed of 320A resin.

In this case, the ball passage forming portions 321, 321 are integrally connected with the inner guide forming portions of change of direction passages 322A through the thin plate portion 329A, as in the first embodiment.

The change-of-direction inner guide forming portions 322A are also integrally connected with the resin tubes 323 through the thin plate portion 329A. In this case, the resin tube 323 is formed in an integral tubular body, although the semitubular elements are employed in the third embodiment. Consequently, there is no insertion hole 334 in the thin plate portion 329A, and the ball return passage 309 is exposed on the thin plate portion 329A.

The first frame formed of resin 320A and the second frame formed of resin 320B are connected, as shown in Figure 32, by a joining method which employs a combination of a cavity and a protrusion to be inserted therein, as a joining method to cap. In the illustrated example, a cavity portion 336 of a dovetail groove is formed in the second frame formed of resin 320B, and an engaging projection 335 to engage with the cavity portion 336 is formed on the other hand, in the portions 321, 321 of formation of passage of spheres.

In this case, the resin tube 323 of the first resin formed frame 320A is inserted into the through hole 314 of the main body 313, and the ball passage forming portions 321, 321 and the connecting plate portion 326 are inserted along the inner surface of the recess 307 of the main body 313.

Then, the engaging projections 335 formed on the respective free end portions of the ball passage forming portions 321, 321 and the connecting plate portion 326 are engaged with the cavity portions 336 formed on the thin plate portion 329B of the second frame formed of resin 324B, which is disposed on the other end surface of the main body 316.

The cavity portions 336 may be formed on the first formed resin frame 320A and the engaging projections 335 may be formed on the second formed resin frame 320B. The connection method is not limited to the method described above, any conventional connection method can be employed, in which the ends of the split parts can be held in an appropriate connection position and connected.

[Second modification]

Figures 33 and 34 show the second modification of the formed body of resin 320 to form the ball circulation passage, which is described in the third embodiment.

In the second embodiment, the resin body 320 formed to form the ball circulating passage, which was obtained by integral forming of both the ball passage forming portions 321, 321 and the resin tubes 323 as the ball forming portion ball return passage with a pair of inner guide forming portions of change of direction passage 322, 322, is divided into the central part of each of the ball passage forming portions 321, 321 and the ball passage forming portions 323 return passage of spheres,. in two parts. More specifically, the ball passage forming portions 321, 321 and the ball return passage forming portions 323 are divided, in their central portion, into the two respective half-parts, and each of the two thus divided half-parts is integrally formed with the change-of-direction inner guide forming portions 322, 322, thereby forming two resin formed frames 320C, and 320D having substantially the same shape.

Cavity portions 338 and the engaging projections 337 to be inserted therein are formed on the split ends of the ball passage forming portions 321, 321, in the split ends of the central connecting plate portion 326 and in the split ends of the resin 323.

[Third modification]

Figure 35 demonstrates the third modification of the formed resin body 320 to form a ball circulation passage, which is described in the third embodiment.

In the third embodiment, the resin tube 323 is not employed as the return passage forming portion described in the first embodiment and a resin formed frame 320E is obtained by integral forming of the ball passage forming portions, plate portions of connection 326 with the thin plate portions 329, 329, each having a pair of the inner guide forming portions of the change of direction passage 322, 322. The ball return passageway 309 is composed of a through hole formed on the main body 313.

In this case, an engaging projection 339a which is engageable with a tapered portion 315 formed on the opening end of the ball return passage 309 may be formed in the opening end of the ball hole 339 of the thin plate portion 329. Such a structure allows for proper connection of the end of the ball return passage 309 and the inner guide forming portion of the change of direction passage 322.

In the illustrated example, an arcuate engaging projection 348 is additionally formed on the connecting portion of the outer guide groove 310b formed on the side cover plate 340 with the ball return passage 309. The engaging projection 48 can be engaged with the thin plate portion 329.

[Fourth modification]

Figure 36 shows the fourth modification of the formed body of resin 320 to form the ball circulation passage, which is described in the third embodiment.

In the fourth modification, the resin tube 323 described in the third modification is not employed, a frame formed of resin 320F is obtained by integrally forming the ball passage forming portions 321 with the inner guide forming portions of the change passages. direction 322 for one side, the other formed frame of resin 320G equipped with inner guide forming portions of change of direction 322 for the other side is separately formed from the aforementioned formed frame of resin 320F, and the frames formed of resin 320F, 320G are connected to each other by the engagement of the projection 335 with the cavity 336. The structure other than the aforementioned construction, is the same as that of the third modification.

In the third embodiment described above, three sets of resin formed bodies are employed to form the ball circulation passage, each of which is divided into two parts. Six sets of resin formed bodies may, however, be employed for the respective circulation passages. The single set of resin formed body may also be employed. In this case, the method of dividing the formed body of resin should be based on the first, second and fourth modifications described above, taking into account the difficulty of inserting the formed body of resin into the main body of the outer tube.

[Modifications of the train of balls]

In the third embodiment and in the first to fourth modification thereof, the ball groove unit has the ball train of the angular contact type. The present invention can also be applied to the ball spline unit having the radial contact type ball train, as shown in Figure 37. In such a radial contact type ball train, the spline shaft has no protrusion. on the outer periphery so as to manifest a circular cross section and the outer tube has no cavity in the inner periphery so as to manifest the hollow cylindrical shape. The ball train of the radial contact type has the smallest contact angle a that the ball train of the angular contact type. With respect to the division method of the resin formed body 320 to form the ball circulation passage, all of the models described in the third embodiment and in the first to fourth modification thereof are employed.

In the example illustrated in Figure 37, six bodies formed of resin 320 to form the ball circulation passage are procured separately from each other for the six respective ball trains. The two sets of resin formed bodies 320 mentioned above can be integrally formed with each other to prepare three sets of resin formed bodies 320 having the six ball circulation passages. The single resin formed body having the six ball circulation passages may also be employed.

[FOURTH REALIZATION]

Figures 38 and 39 illustrate the fourth embodiment of the present invention. In the fourth embodiment, the present invention is applied to a roller groove unit, the rollers of which are used as rolling elements.

The roller spline unit 401 as shown in Figure 38 is composed of a spline shaft 402 as a linearly extending guide member and an outer tube 404 arranged to be movable along the spline shaft 402 through the rollers 403 as rolling elements.

The spline shaft 402 is formed in a long bar shape having a modified cross section. The spline shaft 402 has on its outer periphery three protrusions 406. The roller running surfaces 405, 405 are formed on the two sides of each of the protrusions 406, so as to provide the total number of running surfaces of six.

The outer tube 404 has on its inner periphery three recesses 407 corresponding to the projections 406 of the spline shaft 402, respectively. Roller running counter surfaces 408, 408 are formed on the two corners of each of the cavities 407 so as to correspond to the aforementioned roller running surfaces 405, 405.

In addition, the outer tube 404 has six passages 409, 409; 409, 409; 409, 409, for the return of the rollers, which are parallel with the six counter surfaces 408, 408; 408, 408; 408, 408, roll drop and six change-of-direction passes 410, 410; 410, 410; 410, 410 formed in a U-shaped tube, connecting the ends of the aforementioned counter surfaces 408, 408; 408, 408; 408, 408 of stroke of the rollers with the ends of the aforementioned passage 409, 409; 409, 409; 409, 409 return of the rollers. Outer tube 404 has six circulation passages like this.

The rollers 403 inserted into each of the circulation passages are connected to each other by the same roll retainer 412 as the roll retainer 212 shown in Figure 19, so as to form the train of rollers 403 The rollers 403 are guided by the roll retainer 412 and circulated in each of the circulation passages.

The outer tube 404 is composed of a tubular main body 413 having counter-grooves 408, 408; 408, 408; 408, 408 of the stroke of the rollers, three bodies formed of resin 420, 420, 420 to form the passage of circulation of balls, which are to be inserted in the main body 413, and a pair of side cover plates 440, 440 fixed on both ends of the main body 413 after the insertion of the formed bodies of resin 420, 420, 420 into the main body 413.

In the fourth embodiment, the six circulation passages are formed by three formed bodies of resin 420, 420, 420 as in the third embodiment.

Each of the resin formed bodies 420 to form the ball circulation passage has a pair of the roller passage forming portions 421, 421 extending along the longitudinal side edges of the roller running counter groove 408, a pair of roller passage portions 421, 421. internal change-of-direction passage guide formation 422, 422 provided on the two ends of the main body 413, and resin tubes 423 as the return passage formation portion, which are inserted into through holes formed in the main body 413.

The roller passage forming portions 421, 421 are provided with guide grooves for guiding the two side edges of the belt portion 412b of the roller retainer 412 into a loaded area. The guide grooves can prevent the roller retainer 412 from not only swinging during the travel of the rollers, but also from deflecting by engaging the side edges of the belt portion 412b with the guide groove 421a, when the outer tube 404 is removed from spline shaft 402. Rollers 403 are supported by roll retainer 412. More specifically, the roller retainer 412 is supported by a jaw portion of the guide groove 421a, with the result that the rollers 403 are held in their proper position so as not to come off the outer tube 404.

Guide grooves 409c, 410c are also formed in the roll return passage 409 and the direction change passage 410 as unloaded areas, in order to guide the side edges of the belt portion 412b. The guide grooves 409c, 410c are connected to the aforementioned guide groove 421a in the loaded area so as to form an endless groove in the entire periphery.

When the roller retainer 412 is not employed, the guide grooves 421a, 410a, 409a are not needed, and the jaw portions as shown in FIG. 20 (h) for supporting the ends of the roller are formed on the portions 421 of roll passage formation.

In each of the resin formed bodies 420 to form the roll circulation passage, at least one of the four connecting portions of the roller passage forming portions 421, 421 with the pair of the inner guide forming portions of the change passage direction 422, 422, are integrally connected with each other. The resin formed body 420 is divided into the other portions into separate parts so as to be able to be inserted into the main body 413.

The basic embodiment of the resin formed body to form the roll circulation passage which is to be used for the groove unit is described in detail in the third embodiment. The structure of the resin formed body to form the roller circulation passage is described in detail in the second embodiment. Here, only the fundamental split pattern of the resin formed body 420 to form the roll circulation passage will be briefly described below with reference to FIG. 39.

In Fig. 39 (a), the two ends of the four sets of portions 421, 421 forming roller passage are integrally connected with the respective one end of the pair of inner guide forming portions of change of direction 422, 422 for form a single resin frame 424, and the two ends of each of the portions forming the return passage 423 are not connected with the other end of the change-of-direction inner guide forming portion 422, so that these parts they can be assembled in the main body 413.

In Figure 39 (b), the body formed of resin 420 to form the roller circulation passage is composed of a first resin frame 420A, which is obtained by integrally connecting both of the portions 421, 421 for forming the passage of the rollers and the resin tubes 423 as a return passage forming portion at their ends with the change-of-direction internal guide forming portions 422A for one side, and the second resin formed frame 420B, which is provided with forming portions of internal guide of change of direction passage 422B for the other side, and separately formed by the first frame formed of resin 420A.

In Figure 39 (c) the resin formed body 420 to form the roller circulation passage, which was obtained by integrally forming both roller passage forming portions 421, 421 and resin stubs 423 as the formation portion of return passage with a pair of direction change passage inner guide forming portions 422, 422, is divided into the central portion of each of the roll passage forming portions 421, 421 and return passage forming portions 423, in two parts. More specifically, the roller passage portions 421, 421 and the resin tubes 423 are divided in their central portion into the respective two halves, and each of the two thus divided halves is integrally formed with the inner guide forming portions for the passage of change of direction 422, 422, thus forming two formed frames of resin 420C, 420D, having substantially the same shape.

In Figure 39 (d), the resin tube 423 is not employed as shown in Figure 39 (a), and the frame formed of resin 420E is obtained by integrally forming both of the passage forming portions of the rollers and of the plate portion of connection 326 with the thin plate portions 429, 429, each having the pair of inner guide forming portions of the change-of-direction passage 422, 422. The roller return passage 409 is composed of a through hole formed in the main body 413.

In Figure 39 (e) the resin tube 423 is not used as shown in Figure 39 (b), and a frame formed of resin 420F is obtained by integrally forming the roller passage forming portions 421 with the guide forming portions internal change-of-direction passage 422 for one side, the other resin formed frame 420G equipped with the internal guide forming portions of change-of-direction passage 422 for the other side is separately formed from the aforementioned resin formed frame 420F.

In Figures 39 (a) through 39 (e) the resin formed frames are connected to each other by the conventional joining method, such as a plug joint, which makes use of the engagement of the engaging projection with the cavity.

[FIFTH REALIZATION]

Figures 40 through 44 show linear motion guide apparatus of the fifth embodiment of the present invention.

The linear motion guiding apparatus 501 is provided with a guide rail 502 as a guiding element, which extends linearly, and a movable block 504 as a movable element, which is arranged to be movable along the guide rail 502 through a large number of 503 balls as rolling elements.

Guide rail 502 is formed in a long bar shape having a rectangular cross section. Two ball race grooves 505, 505 as a rolling element raceway are formed on each of the left and right side surfaces of the guide rail 502, so as to provide a total number of grooves 505 of four. The guide rail 502 has on each of its lateral surfaces a protrusion 502a, on the upper and lower positions of which the ball running grooves 505, 505 are arranged.

The movable block 504 is formed as a block body having an inverse U-shaped cross section, with its opening end facing downward. The locking body is provided with a horizontal portion 506 which faces the upper surface of the guide rail 502 and with a pair of wing portions 507, 507, which extend downwards from the right and left ends, of the portion 506 and face the right and left surfaces of the guide rail 502, respectively. Each of the wing portions 507, 507 has on its inner surface two ball race counter-grooves 508, 508 as the running mating track of the rolling element, which correspond to the ball race grooves 505, 505 formed on the right and left side surfaces of the guide rail 502.

Each of the left and right wing portions 507, 507 of the movable block 504 has two ball return passage forming portions 509, 509 formed therein which extend parallel to the ball run counter grooves 508, 508. At both longitudinal ends of each of the wing portions 507, 507, direction change passages 510, 510 are disposed; 510, 510 to connect the ends of the counter grooves 508, 508; 508, 508 of running balls with the ends of the passage 509, 509; 509, 509 ball return. In summary, each of the wing portions 507, 507 of the movable block 504 has two endless circulation passages, in which the balls 503 are circulated, so as to provide the total number of passages of four.

In each of the four endless circulation passages in this embodiment, the balls 503 are held in the form of a train by a ball retainer 512 as a rolling element retainer so that the balls 503 can be circulated while are guided by the ball retainer 512.

As shown in Figures 44 (c) to 44 (e) the ball retaining device 512 comprises a flexible ribbon portion 512b which is provided with ball holes 512a for receiving the balls 503 respectively, and with spacer portions 512c provided between the two adjacent spheres 503, 503. The ribbon portion 512b has a width greater than the diameter of the sphere 503 so that both side edges of the ribbon portion 512d extend outwardly from the sphere 503.

The spacer portion 512c is provided with a spherical bearing cavity 512d corresponding to the spherical surface of the sphere 503. The sphere 503 is supported on its two sides by a pair of spherical bearing cavities 512b so as to prevent the sphere 503 from being away from the tape portion 512b. In this embodiment, the one end of the ribbon portion 512b is not connected to the other end thereof, thus forming a strip-shaped ribbon having the two ends. The one end of the ribbon portion 512b may be connected to the other end thereof to form an endless ribbon.

As shown in Figure 41, the movable block 504 is composed of a block body 513 having counter-grooves 508, 508, 508, 508 for running the balls, by a pair of bodies formed of right and left resin 520, 520 to form passages of circulation of balls, which is inserted in the block body 513, and by a pair of side cover plates 540 (only one side cover plate is shown) fixed to the two end surfaces of the block body 13, in which the formed bodies of resin 520, 520.

Each of the right and left resin bodies 520, 520 formed to form the ball circulation passage forms two endless circulation passages. The right and left resin bodies 520, 520 have the symmetrical shape. One of them will be described below and the description of the other will be left out.

More specifically, the resin body 520 to form the ball circulation passage is composed of a resin frame 524 obtained by integrally forming the ball passage forming portions 521, 521 extending along the two longitudinal sides of the counter groove. 508 of running balls with the pair of inner guide forming portions of change of direction passage 522, 522 (see Figure 42); and a pair of resin tubes 523, 523 as a return passage forming portion, which are to be inserted into through holes 514, 514 formed in the block body 513 (see Figure 43). The ball passage forming portions 521, 521 are integrally formed with the pair of change direction passage inner guide forming portions 522, 522 to form the resin frame 524 as an integral body, and a pair of conducting tubes resin 523, 523. are formed separately from the integral body, so that these parts can be assembled in the block body 513.

As shown in FIG. 42, the ball passage forming portions 521, 521 are provided with guide grooves for guiding the two side edges of the belt portion 512b of the ball retainer 512 into a loaded area. The guide grooves can prevent the ball retainer 512 from not only swinging during the travel of the balls, but also from bending by engagement of the side edges of the belt portion 512b with the guide groove 521a, when the movable block 504 is removed from the guide rail 502. The balls 503 are supported by the ball retainer 512. More specifically, the ball retainer 512 is supported by a jawed portion of the guide groove 521a, with the result that the balls 523 are held in their proper position so as not to come off the movable block 504.

The distance between the pair of ball passage forming portions 521, 521 arranged parallel to each other on the two longitudinal sides of the ball run counter-groove 508 is slightly smaller than the diameter of the ball 503. In such a structure it is possible preventing the balls 503 from coming off the ball passage forming portions 521, 521 even when the ball retaining device 512 is not used.

Guide grooves 509c, 510c are also formed, as shown in FIGS. 44 (a) and 44 (b) in the ball return passage 509, 509 and the direction change passage 510, 510 as unloaded areas, for the purpose of guide the side edges of the belt portion 512b. The guide grooves 509c, 510c are connected to the aforementioned guide groove 521a in the loaded area, so as to form an endless groove over the entire periphery.

Portions 521, 521; 521, 521 of ball passage formation are composed, as shown in Figure 42 (a), by the first connecting plate portion 525 extending longitudinally along the angle between the horizontal portion 506 and the wing portion 507 of the body of block 513 in the longitudinal direction of the block body 513; by the second connecting plate portion 526 extending longitudinally between the ball run counter-swings 508, 508 on the inner surface of the wing portions 507 of the block body 513, and by a pair of third connecting plate portions 527 extend along the surface of the wing portion 507 of the block body 513 in its longitudinal direction.

The upper edge of the first connecting plate portion 525 and the lower edge of the second connecting plate portion 526, which face each other, are located on the opposite longitudinal sides of the counter-groove 508 of approximately upper spheres provided on the wing portion 507, so as to form the ball passage forming portions 521, 521. The lower edge of the second connecting plate portion 526 and the upper edge of the third connecting plate portion 527, which face each other, are located on the opposite longitudinal edges of the lower ball run counter-groove 508 provided in the wing portion 5076, so as to form the ball passage forming portions 521, 521.

As shown in Figs. 44 (a), 44 (b) and 44 (c) the change-of-direction inner guide forming portions 522 and the ball pass-through forming portions 521, 521 are connected by the a thin sheet 529 through integral forming. The resin tube 523 is inserted into a hole 534 formed on the thin plate portion 529 to provide a plug joint, and is attached to the thin plate portion 529.

The thin plate portion 529 has the change-of-direction inner guide forming portions 522, 522 which are formed to correspondingly protrude the two ball trains 503, 503 on the side surface of the guide rail 502. The two ends of the first, second and third connecting plate portions 525-527 are connected to the thin plate portion 529 to be disposed on the block body end 516 to form a single resin frame 524.

Each of the change-of-direction inner guide forming portions 522 has a semi-cylindrical shape. An inner guide groove 510a having a semicircular cross section is formed on the outer periphery of the inner guide portion of the change of direction passage 522 to form the inner guide portion for the change of direction passage 510. The one end of the inner guide groove 510a is connected to the end of the ball run counter groove 508. Accordingly, the one end of the inner guide groove 510a has the same cross-sectional shape as the ball run counter groove 508 so as to provide an alignment of the one end of the inner guide groove 510a with the end of the counter groove. 508 of running balls. The other end of the inner guide groove 510a of the change of direction passage 510 is connected to the end of the ball return passage 509. Consequently, the other end of the inner guide groove 510a has the same cross-sectional shape as the ball return passage 509, thereby providing an alignment of the other end of the internal guide groove 510a with the end of the passage. 509 ball return.

Cylindrical flange portions 533, 533 are formed on the two ends of the inner guide groove 510a. The distance between the respective outer surfaces of the cylindrical flange portions 533, 533 is greater than the width of the belt portion 512b. The cylindrical flange portions 533, 533 form a retaining device guide groove 510c for the ball retaining device 512 in cooperation with a semicircular cavity portion having cutouts, which is formed on the inner periphery of the cavity of the side cover plate 5040 described below.

Both ends of the inner guide groove 510a for the change of direction passage 510 extend to the contact surface of the thin plate portion 529 with the end surface of the block body 513 so as to be connected to the respective ends of the counter groove 508 of ball race and ball return passage 509. Holes 534, 534 for inserting tubes having a semicircular shape, into which the ends of the resin tubes 523 are to be inserted, are formed on the thin plate portion 529.

As shown in Figure 43, the resin tube 523 is composed of an outer peripheral lateral half tubular element 523b located on the outer peripheral side of the ball circulation passage, which is continuously connected to the outer guide groove 510b for the passage of direction change 510 of the side cover plate 540, and by an inner peripheral side half tubular member 523a located in the inner peripheral side of the ball circulation passage, which is continuously connected to the inner guide groove 510a for the change passage direction indicator 510 of the side cover plate 540.

The inner peripheral side half tubular member 523a has a groove portion 509a having a semicircular cross section, and side edge portions 523c extending longitudinally along the groove portion 509a, as shown in Figures 43 (c) and 43 ( d). The outer peripheral side half tubular element 523b is formed into a linear element having the same circular cross section as the outer guide groove 510b for the change of direction passage, which is formed on the side cover plate 540. The element outer peripheral side half tubular 523b has a groove portion 509b, which is continuously connected with the outer guide groove 510b. The lateral edge portions 523d extending longitudinally along the groove portion 509b, and the lateral edge portions 523d are provided on their outer edges with protrusions 523e, which are to be brought into contact with the outer edges of the lateral edge portions 523c of the inner peripheral side half tubular member 523a to form the retainer guide groove 509c for the ball retainer 512.

The inner peripheral side half tubular element 523 of the resin tube 523 has the same length as the block body 513. The inner peripheral side half tubular element 523a is positioned to be brought into contact with the rear surface of the portion of formation of internal driving of passage of change of direction 522.

The outer peripheral lateral half tubular element 523b of the resin tube 523 has, on the other hand, a greater length than the block body 513 by an amount corresponding to the thin plate thickness 529. The outer peripheral lateral half tubular elements 523b are inserted into the insertion holes 534. A determination of the longitudinal position of the outer peripheral lateral half tubular element 523b is carried out by bringing the two ends of the outer peripheral lateral half tubular element 523b inserted into the insertion hole 534 into contact with the edge peripheral of the end portion of the outer guide grooves 510b for the change of direction passage, which are formed on the side cover plate 540. The protrusions 523e formed on the two side edges of the outer peripheral side half tubular element 523b contact with the outer edges of the cylindrical flange portions 533 formed on the portion change-of-direction inner guide forming element 522 to form a part of the guide groove 510c, and the outer peripheral side half tubular element 523b and the inner peripheral side half tubular element 523a are limited to turn in the insertion hole 514.

The resin tubes 523 and the change-of-direction inner guide forming portions 522 are precisely positioned through the insertion holes 534 formed on the thin plate portion 529, and proper assembly is made in this manner.

As shown in Figures 44 (f) and 44 (g), the side cover plate 540 is provided with an insertion cavity portion 540a, into which the thin plate portion 529 is inserted, of cavity portions 541 having the grooves direction change outer guide portions 510b, in which portions of the direction change passage inner guide forming portions 522 are adapted, and screw fastening portions for securing the side cover plate 540 to the lock body 513. In the screw fastening portions, the side cover plate 540 is secured to the lock body 513 by inserting bolts (not shown) into holes 543 formed on the side cover plate 540 and engaging the bolts with threaded holes 545 formed on the surface of end of the block body 513. The holes 543 are located in four positions, i.e. the position corresponding to the thin plate portion 529 between the guiding portions. a change of direction passage interior 522, 522 of each of the resin formed bodies 520, 520, and the locations in the vicinity of the thin plate portions 529, 529 on the horizontal portion 506.

As shown in Fig. 44 (g), the outer guide groove 510b for the change of direction passage in the recess portion 541 has on its side edges arcuate recesses 546 of larger diameter, which form the device guide groove 510c retainer in cooperation with the cylindrical flange portions 533 of the change-of-direction inner guide forming portions 522 as shown in Fig. 44 (f), and arcuate recesses 547 of smaller diameter, into which the flange portions are inserted cylindrical 533. The internal guide forming portion of the change of direction passage 522 provided with the internal guide groove 510a for the change of direction passage is adapted in the recess portion 541 of the side cover plate 540 and the thin plate portion 529 is received in the insertion cavity portion 540a of the side cover plate 540. The thin plate portion 529 vi is held between the side cover plate 540 and the end surface of the lock body 313 by a clamping force so as to fix it exactly between them.

The change-of-direction inner guide forming portion 522 and the ball passing forming portion 521 are connected through the thin plate portion 529, thus making it possible to maintain an accurate position relationship of the end of the inner guide groove 510a for the change-of-direction passage formed in the internal guide-forming portion of the change-of-direction passage 522 relative to the ball passage-forming portions 521, 521 as well as an accurate position relationship of the internal guide groove 510a for the direction change passage relative to ball return passage 509.

The thin plate portion 529 located in proximity to the change-of-direction inner guide forming portion 522 is uniformly pushed against the flat end surface of the lock body 513 through a clamping force applied to the side cover plate 540 ( see figure 44). Even when the change-of-direction inner guide forming portion 522 is not located in a correct position, the thin plate portion 529 changes its shape on the end surface of the block body 513, thus allowing correct positioning of the change-of-direction inner guide forming portion 522. The thin sheet portion 529 is firmly clamped and secured by a clamping force which is applied to the cover plate 540 and a frictional force determined by that clamping stage can preventing an unfavorable movement of the inner guide groove 510a for the change of direction passage.

The side cover plate 540 is secured to the lock body 513 so that the change-of-direction inner guide forming portion 522 assembled to the lock body 513 is fitted into the recess portion 541 of the side cover plate 40. This coupling stage allows to perform the precise positioning of the side cover plate 540 relative to the block body 513.

Description will now be made of the assembly steps for the aforementioned resin formed bodies 520 to form the ball circulation passage.

First, the inner peripheral side half tubular element 523a of the resin tube 523 is inserted into the through hole 514 of the wing portion 507 of the block body 513.

Then, the resin frame obtained by integral forming is inserted into the cavity of the block body 513, while it is determined that the thin plate portions 529 at both ends of the resin frame 524 slip on the respective end surfaces of the wing portion 507 of the block body 513. The first connecting plate portion 525 of the resin frame 524 comes into contact with the corner portion between the horizontal portion 506 and the wing portion 507, thus providing a position determination in the vertical direction of the frame of resin 524. The second connecting plate portion 526 and the third connecting plate portion 527 of the resin frame 524 come into contact with the respective outer surfaces of the wing portions 507 of the block body 513, thus providing a determination of position of the ball passage forming portions 521, 521 and of the internal passage guide forming portions d direction change 522, 522. At this point, the insertion holes 534, 534 of the thin plate direction 529 are aligned with the through holes 514, 514 of the block body 513.

Then, the outer peripheral lateral half tubular elements 523b, 523b are inserted into the through holes 514, 514 starting from the insertion holes 534, 534, thus completing the assembly stage of one of the formed bodies of resin 520, 520 to form the passage of circulation of spheres.

The assembly step of the other of the resin formed bodies 520, 520 is carried out in the same way.

Then, the one side cover plate 540 is secured to the one end surface of the lock body 513 by a clamping stage, the ball retainer 512 which holds the balls is inserted, and the other cover plate side 540 is fixed to the other end surface of the block body 513 by means of the same clamping stage, thus completing the assembly stage of the block body 504.

According to the present invention, the resin bodies 520, 520 to form the ball circulation passage are formed separately from the block body 513. Even when the movable block 504 has a larger size, there is no flow restriction of resin melted by the block body 513, unlike the case where the block body 513 is formed integrally with the resin formed bodies 520, 520. An increase in the number of casting attachments formed on the mold can ensure an appropriate course of the cast resin, thus improving formability. Especially the ball passage forming portions 521, 521 located on opposite longitudinal sides of the ball run groove 508 are thin, with the result that the molten resin may not reach each part of the space to form the portions 521, 521 of formation of passage of spheres. It is therefore effective to form the resin formed bodies 520, 520 separately from the block body 513 in accordance with the embodiment of the present invention.

In addition, since the right and left resin formed bodies 520, 520 have formed to form the ball circulation passage, each of which has two endless ball circulation passages, an appropriate course of the molten resin is ensured, also when the movable block 513 has a larger dimension.

The continuous circulation passage is formed by the formed block of resin 520, and it is thus possible to provide a position determination of the inner guide groove 510a for the direction change passage relative to the ball passage forming portions 521, 521, as well as a determination of the position of the inner guide groove 510a for the change of direction passage relative to the ball return passage 509, thus ensuring the continuity of the circulation passage so as to facilitate the circulation of the balls 503.

When the proper position relationship of the inner guide groove 510a for the direction change passage is maintained relative to the ball passage forming portions 521, 521, the ball passage forming portions 521, 521 are located on the two longitudinal sides of the ball run groove 508 so as to be aligned with the ends of the inner guide groove 510a for the change of direction passage.

When the proper position relationship of the internal guide groove 510a for the direction change passage is maintained relative to the ball return passage 509, the internal guide groove 510a for the direction change passage can be aligned with the groove. 523a of the ball return passage 509.

The connecting portion of the ball passageway forming portions 521, 521 and the change of direction internal guide forming portion 522 is obtained by integral forming, thus allowing to leave out an assembly step of the connecting portion. Although the direction of travel of the balls 503 has changed in this connecting portion, the aforementioned integral structure can ensure a continuity of the circulation passage, without being affected by the precision of assembly. It is therefore possible to facilitate the running of the balls 503 from the ball run passage between the ball run groove 505 and the ball run counter-groove 508 to the direction change passage 510, as well as from the direction change passage 510. to ball return passage 509.

According to the present invention as described in detail, since the formed body of resin for the circulation passage of rolling elements is formed separately from the block body, even when the movable block has a larger size, an increase in the number of couplings of casting formats on the mold can ensure an appropriate course of the molten resin, thus improving the formability. It is therefore effective to form the resin formed body separately from the block body in accordance with the present invention, taking into account the fact that the passage forming portions of rolling elements located on opposite longitudinal sides of the raceway of the rolling elements rolling elements are thin, with the result that the molten resin may not reach each part of the space to form the passage forming portions of rolling elements.

The continuous circulation passage is formed by the resin formed body, and it is thus possible to provide a position determination of the inner guide groove for the change of direction passage relative to the passage forming portions of rolling elements, as well as a determining the position of the inner guide groove for the change of direction passage relative to the return passage of rolling elements, thus ensuring a continuity of the circulation passage so as to facilitate circulation of the rolling elements.

When the connecting part of the rolling element passage forming portions and the change direction passage inner guide forming portion or the connecting part of the change direction passage inner guide forming portion is the of formation of the return passage, in which part the direction of travel of the rolling elements is varied, are obtained by integral forming, it is possible to omit an assembly stage of the connection part and ensure the continuity of the circulation passage, without being influenced from the precision of assembly.

The integral forming of the connecting part of the rolling element passage forming portion with the change of direction passage inner guide forming portion can result in smooth running of the rolling elements between the raceway of rolling elements in the The loaded area and the change of direction inner guide forming portion, even when the resin formed back passage forming portion, is not employed.

When the rolling element retainer is employed, it is possible to maintain proper continuity over the entire periphery of the circulation passage in the retainer guide portion for guiding the rolling element retainer.

The thin guide portion of the retaining device is formed without insertion of the body of the movable member into the mold, and the position of the sprues in the mold can be freely determined without being limited by the body of the movable member, with the result that the Molten resin can reach, during the formation of the guide portion, the entire space for it, which is formed in the mold.

In addition, the formation of the formed bodies of right and left resin to form the circulation passage of rolling elements, each of which has two endless circulation passages can ensure proper course of the molten resin, even when the element body cabinet has a greater width.

The connection of the change direction passage inner guide forming portion with the rolling element passage forming portion through the thin plate portion makes it possible to maintain, through deformation of the thin plate portion, an appropriate relationship of position between the change direction passage inner guide forming portion and the rolling element passage portion or an appropriate position relationship between the change direction passage inner guide forming portion and the forming portion return passage forming portion of rolling elements, thereby providing a precise determination of the position of the end of the inner guide forming portion of the change of direction relative to the return passage forming portion of rolling elements as well as an accurate determination of location of the change of direction inner guide forming portion relative to the rolling element return passage forming portion.

The thin plate portion is pushed against the flat end face of the movable member body by a clamping force, which is applied to the side cover plate. It is thus possible to correct the position of the direction change passage inner guide forming portion through a deformation of the thin plate portion, even when the direction change passage inner guide forming portion is not correctly positioned relative to the end face of the body in the movable member.

In addition, the thin plate portion can be firmly fixed between the side cover plate and the body of the movable member, by the clamping force, which is applied to the side cover plate, and it is therefore possible to prevent the change-of-direction internal guide formation is placed incorrectly.

Claims (18)

CLAIMS 1. Linear motion guide apparatus comprising: a guide element provided with a running track of rolling elements, e a movable element arranged so as to be movable along the guide element through a large number of rolling elements, said movable element being provided with (i) a counter-track for running elements of rolling elements corresponding to the running track for rolling elements of said guide element, (ii) of a return passage of rolling elements disposed away from said counter-race of rolling elements by a prescribed distance and parallel to it and (iii) of a pair of change-of-direction passages for connecting the counter-track of rolling elements and the return passage of rolling elements to allow the circulation of the rolling elements, characterized in that: a body formed of resin to form a passage for the circulation of rolling elements comprises a pair of portions for forming the passage of rolling elements which extend along two longitudinal sides of said counter-track for running the rolling elements, a return passage forming portion for forming the rolling element return passage and a pair of change direction passage inner guide forming portions for forming inner peripheral guide portions of said direction change passages, said body formed of resin being formed separately from a body of said movable member; And at least two parts of (a) said pair of rolling element passage forming portions, (b) said return passage forming portion, (c) one of said pair of change passage inner guide forming portions direction and (d) another one of said pair of direction change passage inner guide forming portions are connected to each other through integral forming so that said resin formed body can be incorporated into the body of said movable element. 2. Apparatus as claimed in claim 1, wherein: said resin formed body comprises (i) an integral body of said pair of rolling element passage forming portions and said pair of change direction passage inner guide forming portions, and (ii) said shift portion return passage formation formed separately from said integral body. 3. Apparatus as claimed in claim 1, wherein: said resin formed body comprises (i) an integral body of said pair of rolling element passage forming portions, said return passage forming portion and one of said pair of inner passage guide forming portions change of direction, and (ii) another of said pair of inner guide forming portions of change of direction, formed separately from said integral body. 4. Apparatus as claimed in claim 1, wherein said resin formed body is fabricated by preparing an integral body of said pair of rolling element passage forming portions, said return passage forming portion and said pair of rollers. change of direction inner guide forming portions, and then dividing said pair of rolling element passage forming portions and said return passage forming portion into intermediate longitudinal portions thereof into two respective parts. 5. Linear motion guide apparatus comprising: a guide element provided with a running track of rolling elements, e movable element arranged so as to be movable along the guide element through a large number of rolling elements, said movable element being provided with (i) a counter-track for running elements of rolling elements corresponding to the running track for rolling elements of said guide element, (ii) of a rolling element return passage disposed away from said counter-race of rolling elements by a prescribed distance and parallel with it and (iii) of a pair of change-of-direction passages for connect the counter-track of the rolling elements and the return passage of the rolling elements to allow the circulation of the rolling elements, characterized in that a body formed of resin for forming a rolling element circulation passage comprises a pair of rolling element passage forming portions extending along the two longitudinal sides of said rolling element running counter track and a pair of inner guide forming portions of change of direction passage for forming inner peripheral guide portions of said change of direction passages, said resin formed body being formed separately from a body of said movable member; said return passage of rolling elements is provided by forming a through hole in the body of said movable element, and said pair of passage forming portions of rolling elements and at least one of said pair of internal guide forming portions for passage of direction changes are connected with each other by integral forming. 6. Apparatus as claimed in any of claims 1 to 5, wherein: a rolling element retainer is provided, said rolling element retainer being capable of retaining the rolling elements in a train with a prescribed distance maintained between two of the rolling elements, and said rolling element retainer rolling elements having lateral edge portions projecting from both sides of each of the rolling elements; and guide grooves for guiding the side edge portions of the rolling element retainer are formed over the entire periphery of the rolling element circulation passage. 7. Apparatus as claimed in any of claims 1 to 6, wherein: each of said inner guide forming portions of change of direction has a thin plate portion which is to be brought into contact with an end face of the body of said movable member, and said each of said inner guide forming portions change of direction passageway is connected to the passage forming portions of rolling elements or to the back passage forming portion, by means of said thin plate portion. 8. Apparatus as claimed in any of claims 1 to 7, wherein: said guide element comprises a guide rail; said movable element comprises a movable block, which is provided with a horizontal portion, which faces an upper surface of said guide rail and with a pair of wing portions, between which the guide rail is held on its right side surfaces and left; and two sets of rolling elements are disposed in a gap between the upper surface of the guide rail and a lower surface of the movable block, and a single train of rolling elements is disposed in each of the interspaces between the right and left side surfaces of the guide rail and the two wing portions, so as to provide a total number of trains of 4. 9. Apparatus as claimed in any of claims 1 to 7, wherein: said guide element comprises a guide rail; said movable element comprises a movable block, which is provided with a pair of wing portions, between which the guide rail is held in its right and left side surfaces; And two trains for the rolling elements are arranged in each of the interspaces between the right and left side surfaces of the guide rail and both wing portions, so as to provide a total number of trains of 4. 10. Apparatus as claimed in claim 9, wherein: four change of direction inner guide forming portions are formed correspondingly to the four trains of the rolling elements, respectively, and said four inner guide forming portions of change of direction are integrally connected with each other. other. 11. Apparatus as claimed in claim 9, wherein: two change-of-direction inner guide forming portions located on one side of the right side surface of the guide rail are integrally connected to each other, and the other two inner guide forming portions of change-over passage direction indicators located on one side of the left side surface of the guide rail are integrally connected to each other. 12. Apparatus as claimed in any of claims 1 to 7, wherein: said guide element comprises a guide rail; said movable element is provided with a horizontal portion which faces an upper surface of said guide rail and with a single wing portion which faces a lateral surface of the guide rail; and a single train of rolling elements is disposed in a gap between said one side surface of the guide rail and said single wing portion, and another single train of rolling elements is disposed in a gap between the upper surface of the guide rail. guide and the lower surface of said horizontal portion in proximity to a corner of the guide rail. 13. Apparatus as claimed in any of claims 1 to 7, wherein said guide element comprises a guide rail; said movable element comprises a movable block, which is provided with a pair of wing portions, between which the guide rail is held on its right and left side surfaces; And a single train of the rolling elements is arranged in each of the interspaces between the right and left side surfaces of the guide rail and both wing portions, so as to provide a total number of trains of two. 14. Apparatus as claimed in any of claims 1 to 7, wherein said guide element comprises a guide rail; said movable element comprises a movable block disposed along a lateral surface of the guide rail; And two trains of rolling elements are arranged in an interspace between said one lateral surface of the guide rail and the movable block. 15. Apparatus as claimed in any of claims 1 to 7, wherein: said guide element comprises a splined shaft; And said movable element comprises an outer tube, said outer tube is movably supported on said splined shaft through a plurality of trains of the rolling elements. 16. Linear motion guide apparatus comprising: a guide rail provided with two raceways of rolling elements on each of the right and left side surfaces of the guide rail, so as to provide a total number of raceways of rolling elements of four; And a movable block provided with a pair of wing portions, between which the guide rail is held in its right and left side surfaces, each of said wing portions having on its internal surface two counter-tracks of rolling elements corresponding to said two raceways of rolling elements of the guide rail, so as to provide a total number of counterraces of rolling elements of four, said movable block having four endless circulation passages, which are formed by four passages of return of rolling elements arranged parallel to said four running counter-tracks of rolling elements, respectively, and return passages of rolling elements for connecting the two ends of each of said counter-tracks of rolling elements with the two ends of each of said four return passages of rolling elements, respectively characterized by the fact that: a body formed of resin comprises, for each of said endless circulation passages, a pair of portions for forming the passage of rolling elements which extend along the two longitudinal sides of said counter-track for running the rolling elements, a portion of return passage formation to form the rolling element return passage and a pair of change direction passage inner guide forming portions to form inner peripheral guide portions of said direction change passages, said body formed of resin being formed separately from a body of said movable block; said resin formed body is divided into two body parts, which are arranged on the wing portions of the movable block, respectively, so as to form the two endless circulation passages on an inner side of each of the wing portions; And in each of the two body parts, the rolling element running counter track and the pair of change direction passage inner guide forming portions are formed into an integral body, and the return passage forming portion is formed separately from said integral body. 17. Apparatus as claimed in claim 16, wherein: a rolling element retaining device is provided, said rolling element retaining device being capable of retaining the rolling elements in a train with a prescribed distance maintained between two adjacent rolling elements, and said rolling element retaining device rolling element having lateral edge portions projecting from both sides of each of said rolling elements; And Guide grooves for guiding said side edge portions of the rolling element retainer are formed over the entire periphery of the rolling element circulation passage. 18. Apparatus as claimed in claim 16 or 17, wherein: each of said inner guide forming portions of change of direction has a thin plate portion, which is to be brought into contact with an end face of the body of said movable element and said each of said inner guide forming portions change of direction passage is connected to the passage forming portions of rolling elements or to the back passage forming portion by said thin plate portion.