JP2002039175A - Spacer for linear movement device and linear movement device using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spacer for a linear movement device being excellent in the ability to retain lubricant, being strong although lightweight, and having reduced areas of contact with rolling elements, and a linear movement device using the spacer. SOLUTION: The spacer 5 for the linear movement device, which is interposed between a plurality of rolling elements 4 and 4 arranged and contained in the endless circulation path of the linear movement device, comprises a shell part 12 arranged so that its axis approximately coincides with a line connecting the centers of the rolling elements 4 and 4, with both axial ends 12a and 12a of the shell part making contact with the rolling elements 4 and 4; and a rib 13 molded integrally with the shell part 12 to divide a space within the shell part 12. The plurality of spaces S axially pass through the shell part 12. A large amount of lubricant such as grease can be retained in the plurality of spaces formed within the shell part, whereby the spacer excellent in the ability to retain the lubricant can be obtained. Because the shell part is reinforced by the rib, the shell part and the rib can be made thinner and the spacer made lightweight as a whole.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spacer for a linear motion device interposed between rolling elements such as balls or rollers arranged and housed in an infinite circulation path of the linear motion device, and a spacer for the linear motion device. Linear motion device.

[0002]

2. Description of the Related Art Spacers are provided between rolling elements such as balls or rollers arranged and housed in an infinite circulation path of a linear rolling guide device, a ball screw, a ball spline and the like (hereinafter, these are collectively referred to as a linear motion device). Intervening has been done for quite some time. By interposing the spacer, the rolling elements do not directly contact each other, the distance between the rolling elements is kept substantially constant, the linear motion device operates smoothly, and noise is prevented from being generated.

A spacer shown in FIG. 17 is known as a spacer for preventing rolling elements from directly contacting each other (see Japanese Patent Application Laid-Open No. 10-281154). FIG.
This shows a state in which balls 91 as rolling elements are fitted into spacers 92. The spacer 92 is formed in a substantially cylindrical shape, and concave portions 92a and 92b into which adjacent balls are fitted are formed at both ends in the axial direction. Recess 9
The balls 2a and 92b are formed so as to conform to the outer periphery of the balls 91 and 91, and guide the rotational movement of the balls 91 and 91. In the deepest portion of the concave portions 92a and 92b, the ball 9
Lubricant reservoirs 93a and 93b are formed slightly deeper so as not to contact the first and the first 91. Lubricant is replenished to the lubricant reservoirs 93a and 93b, and the lubricant 9 is transferred from the lubricant reservoirs 93a and 93b to the balls 91 and 91.
The lubricant is supplied so that 1,91 smoothly rolls. The ball is stably supported by the band-shaped spherical regions 94a and 94b around the deepest portion of the concave portions 92a and 92b.

As another spacer, FIG.
As shown in (a) and (b), there is also known a spacer in which a lubricant reservoir 96 penetrating in the axial direction is formed in the spacer 95 (Japanese Utility Model Laid-Open No. 63-178649).

[0005]

However, in the conventional spacer 92 disclosed in Japanese Patent Application Laid-Open No. 10-281154, the volume of the lubricant reservoirs 93a and 93b cannot be made large, and many lubricants are not provided. Can not hold. In addition, the spacer cannot be made light in weight due to its structure, so that the followability to the movement of the ball is deteriorated, and the ball and the spacer are biased to the outside of the turning path by the centrifugal force when moving on the turning path. Problem arises.

Further, the spacer 95 disclosed in Japanese Utility Model Laid-Open Publication No. Sho 63-178659 can hold a large amount of lubricant, but the strength becomes insufficient due to the increase in the volume of the lubricant reservoir 96, and the spacer 95 There is a problem in that the spacer 95 is easily deformed by an axial compression force or a radial force applied to the spacer 95.

Accordingly, the present invention provides a spacer for a linear motion device which is excellent in holding capacity of a lubricant, is lightweight, has strength, and has a small contact area with a rolling element, and a linear motion device using the spacer. The purpose is to:

[0008]

The present invention will be described below. In addition, in order to facilitate understanding of the present invention, reference numerals in the accompanying drawings are added in parentheses, but the present invention is not limited to the illustrated embodiment.

In order to solve the above problems, a first aspect of the present invention is a spacer for a linear motion device interposed between a plurality of rolling elements (4, 4) arranged and housed in an infinite circulation path of the linear motion device. (5) a shell arranged so that an axis thereof substantially coincides with a line connecting the centers of the rolling elements (4, 4), and both ends (12a, 12a) in the axial direction contacting the rolling elements (4, 4). And a rib (13) integrally formed with the shell (12) so as to separate a space inside the shell (12), and a plurality of the spaces (S) are provided in the shell (12). (12) is penetrated in the axial direction.

According to the present invention, a large amount of lubricant such as grease can be held in a plurality of spaces formed in the shell portion, and a spacer having excellent lubricant holding ability can be obtained.
In addition, the scattering of the lubricant can be prevented by the shell constituting the outer periphery of the spacer, and the lubricant can be retained for a long period of time, so that the capability of retaining the lubricant is improved. Further, since the shell portion is reinforced with the rib, the shell portion and the rib can be made thinner, and the spacer can be made lighter as a whole. Therefore, the followability of the spacer to the rolling elements is improved, and the centrifugal force applied to the spacer in the direction change path is minimized. As a result, a jump (bias) to the outside of the direction change path due to the centrifugal force is suppressed, and the held lubricant does not scatter. Further, since both ends of the shell contact the rolling elements, the contact area between the shell and the rolling elements is small. Therefore, friction is suppressed, wear is reduced, and the rolling elements circulate smoothly.

The reason why the shell and the rib can be made thin will be described. The shell is originally resistant to compressive forces in the axial direction and is reinforced in the radial direction by ribs, so that the shell can be made thin. On the contrary, since the outer periphery of the rib is reinforced by the shell, the rib can be made thin.

Further, according to the invention of claim 2, the rib (1)
Both ends (13b, 13b) in the axial direction of (3) are also in contact with the rolling elements (4, 4).

According to the present invention, not only the shell but also the rib comes into contact with the rolling element, so that the rib can guide the rolling motion of the rolling element. In addition, the rib not only reinforces the spacer in the radial direction, but also applies the axial load applied to the spacer itself, so that the contact pressure between the rolling element and the spacer is reduced, and the friction between the spacer and the rolling element is reduced. Can be reduced.

Further, according to the invention of claim 3, the shell (1)
The contact surface of the rib (13) with the rolling element (4, 4) is formed in a curved surface corresponding to the outer peripheral surface of the rolling element (4, 4).

According to the present invention, the rolling motion of the rolling element can be more reliably guided, the contact area between the rolling element and the spacer can be increased, and the contact surface pressure between the rolling element and the spacer can be reduced. Smaller.

Further, according to the present invention, the rib (13) is
It is characterized by comprising at least three rib components (13a...) Radially arranged at equal intervals from the axis of the shell (12) toward the shell (12).

According to the present invention, the shell can be reinforced substantially uniformly in all directions in the radial direction.

Further, according to the present invention, the shell portion (12) includes:
It is characterized in that it is formed in a cylindrical or square frame shape having a constant cross-sectional area in the axial direction.

According to the present invention, it is possible to obtain a shell having strength against a compressive force in the axial direction.

Further, according to the present invention, the plurality of spaces (S
..) Are formed on the axis of the shell (12).

According to the present invention, by forming a space for storing the lubricant on the axis of the shell, the lubricant can be efficiently supplied to the contact portion of the ball with the rolling groove.

The present invention also provides a rolling element rolling surface (2a, 2a).
b) and the rolling element rolling surface (2)
a slide member (3) having a rolling element circulation path including a load rolling surface (3a, 3b) corresponding to the rolling member (a, 2b) and being mounted on the track shaft (2) so as to be relatively movable; A plurality of rolling elements (4...) Arranged and accommodated in a moving body circulation path and circulating in accordance with the relative movement of the slide member (3) with respect to the orbital axis (2); ), A plurality of linear motion device spacers (5...) Interposed therebetween, wherein each linear motion device spacer (5) has a center of the rolling element (4, 4). The shell (12) is disposed so that the axis thereof substantially coincides with the connecting line, and separates the space inside the shell (12) from the shell (12) whose both ends (12a, 12a) in the axial direction are in contact with the rolling elements (4, 4). And a rib (13) integrally formed with the shell (12) as described above. S) can also be configured as a linear motion and wherein the penetrating the shell portion (12) in the axial direction.

[0023]

1 and 2 show a linear rolling guide device 1 incorporating a linear motion device spacer according to a first embodiment of the present invention. This linear rolling guide device 1 guides a movable body such as a table so as to linearly move on a fixed portion such as a bed or a saddle.
A guide rail 2 (track axis) which is disposed on a fixed portion and has ball rolling grooves 2a and 2b formed in the longitudinal direction.
A ball circulation path including a load rolling groove 3a corresponding to the ball rolling groove 2a of the guide rail 2 is formed, and the moving block 3 (slide member) assembled so as to be relatively movable along the guide rail 2. A plurality of balls (rolling elements) 4 arranged and accommodated in the ball circulation path and circulated in accordance with the relative movement of the moving block 3 with respect to the guide rail 2;
A plurality of spacers 5 interposed between a plurality of balls 4.
And.

The guide rail 2 has a substantially rectangular cross section and is elongated and linearly extended. On the upper surface of the guide rail 2, there is a track 2 on which the ball 4 rolls over the entire length in the longitudinal direction.
A ball rolling groove 2a is formed near the left and right edges of the upper surface of the rail, and a single ball rolling groove 2b is formed on each of the left and right side surfaces of the guide rail 2 to provide a trajectory when the ball 4 rolls.
Is formed on the upper side. The guide rail 2 is provided with a plurality of bolt mounting holes for fixing on the fixing portion in the longitudinal direction. Although the illustrated guide rail 2 is straight, a curved rail may be used. Further, the ball rolling grooves 2a and 2b are provided in total of four on the upper surface and two on the left and right side surfaces, but the number of the balls can be variously changed according to the use of the linear rolling guide device 1. .

The moving block 3 is schematically constructed by combining a main body 6 and a pair of side covers 7 arranged at both ends thereof with bolts. As shown in FIG. 2, the main body 6 includes a main body block 6a and molded bodies 6b and 6c.
The main body block 6a is a highly rigid structure made of steel or the like so as to withstand the load on the moving block 3,
A screw hole for fixing an object to be guided by the device is formed on the upper surface. The molded bodies 6b and 6c inject molten resin into a mold in which the main body block 6a is installed.
It is formed integrally with the main body block 6a by a so-called insert molding method. Here, the molded bodies 6b and 6c may be die-cast using metal such as aluminum instead of resin. The present invention is not limited to the insert molding, and the main body block 6a and the molded bodies 6b and 6c may be formed separately and assembled later. The body block 6a and the molded bodies 6b and 6c are both MIM
(Metal Injection Mold).

The main body 6 has a horizontal portion 8 facing the upper surface of the guide rail 2 and left and right sleeve portions 9 hanging down from the horizontal portion 8 and facing left and right side surfaces of the guide rail 2. The horizontal portion 8 is formed with two load rolling grooves 3a opposed to the two ball rolling grooves 2a on the upper surface of the guide rail 2, respectively.
, A load rolling groove 3b facing the ball rolling groove 2b on the side surface of the guide rail 2 is formed. This ball rolling groove 2
The load rolling path A is formed by a combination of the load rolling grooves 3a and 3b. Two through holes extending parallel to the load rolling grooves 3a are formed in the horizontal portion 8, and the tubular portions 6c of the molded body are integrally formed in these through holes. A return passage B for returning the balls 4... Is formed inside the tubular portion 6c. Further, two through holes extending in parallel with the load rolling grooves 3b are formed in both sleeve portions 9,
The tubular portion 6c of the molded body is formed integrally with these through holes. A return passage B for returning the ball is formed inside the tubular portion 6c. The molded body 6b is formed integrally with the main block 6a on the lower surface of the horizontal portion 8 of the main block 6a and on the entire inner surface of the left and right sleeves 9. A ball holding portion 10 is formed on the molded body 6b so as to prevent the balls 4 from falling off the load rolling path A when the moving block 3 is removed from the guide rail 2.

As shown in FIG. 3, inner peripheral guides 6d, 6d project from both ends of the main body block 6a in an arch shape to form a direction change path C in the molded body 6c. On the other hand, the side cover 7 is formed with an outer guide 7a that forms a direction change path C together with the inner guide 6d. When the side lid 7 is attached to the main body 6, the inner peripheral guide 6d and the outer peripheral guide 7a
Are combined to form a direction change path C between them. An infinite circulation path is formed by a combination of the load rolling path A, the U-shaped direction change path C, and the return path B.

As shown in FIG. 3, as the moving block 3 moves along the guide rail 2, the balls 4 move the load rolling path A from one end to the other while receiving the load from the moving block 3. And then one turn course C
And is guided to the return path B, and further returned to one end of the load rolling path A via the direction change path C on the opposite side. Here, on the load rolling path A in the load area, the balls 4 roll while receiving a load, and on the direction change path C and the return path B in the no-load area, the balls 4 circulate without receiving a load.

A plurality of spacers for linear motion devices (hereinafter referred to as spacers 5) are interposed between the plurality of balls 4 arranged and accommodated in the infinite circulation path. 4 to 6 show the spacer 5 incorporated in the linear rolling guide device 1. FIG. The spacer 5 is made of synthetic resin or the like, and is formed by injection molding or the like. As shown in FIG. 4, each spacer 5 is interposed between a pair of balls 4.

The spacer 5 is disposed so that the axis thereof substantially coincides with the line connecting the centers P, P of the pair of balls 4, 4, and the shell 12 whose both ends in the axial direction contact the pair of balls, A rib is integrally formed with the shell so as to separate a space formed in the shell into a plurality of spaces.
The shell portion 12 is formed in a substantially cylindrical shape, and a cross section in a direction orthogonal to the axis is formed in a thin annular shape (ring) having a constant cross-sectional area. Contact surfaces 12a, 12a with the balls 4, 4 at both ends of the shell portion 12 are formed into curved surfaces corresponding to the spherical outer peripheral surfaces of the balls 4, 4 so that the balls 4, 4 fit into the spacers. . The contact surfaces 12a, 12a
Supports the rotational movement of the balls 4, 4 so that the balls slide on the contact surfaces 12a, 12a. The diameter of the shell 12 is about 70% of the ball diameter so that the rotational movement of the balls 4 and 4 can be stably supported and the shell 12 does not collide with the wall surface constituting the infinite circulation path in the infinite circulation path. Is set to The length of the shell 12 in the axial direction is set to be thin so that the distance between the pair of balls 4 becomes short.

The rib 13 is formed integrally with the shell 12 so as to separate a plurality of spaces formed in the shell 12. The rib 13 is formed in a cross-shaped cross section, and includes four rib components 13a, 13a, 13a, 13a radially spaced from the axis of the shell 12 by 90 degrees. The ribs 13 extend in the shell 12 in the axial direction and are filled with a plurality of (four) spaces S, S,
S, S are formed. Both ends of the rib 13 in the axial direction also contact the pair of balls 4, 4, and the contact surfaces 13 b, 13 b, 13 b, 13 b of the rib 13 with the ball are also formed into curved surfaces corresponding to the spherical outer peripheral surface of the ball 4. Have been. Rib 1
The thickness of the spacer 3 is such that the spacer
Is set to have sufficient strength and to be able to store a large amount of lubricant inside the spacer 5.

When the spacer 5 is configured as described above, a large amount of lubricant such as grease can be held in a plurality of spaces formed in the shell portion 12, so that a spacer having excellent lubricant holding ability can be obtained. can get. In addition, the shell 12 constituting the outer periphery of the spacer 5 can prevent the lubricant from scattering and can hold the lubricant for a long period of time, so that the ability to hold the lubricant is improved. Furthermore, shell part 1
2 is reinforced with ribs 13 so that the shell 1
The thickness of the spacers 5 can be reduced by making the ribs 2 and the ribs 13 thin. Therefore, the followability of the spacers 5 to the balls 4 can be improved, and the centrifugal force applied to the spacers 5 on the turning path can be minimized. As a result, a jump (bias) to the outside of the direction change path due to the centrifugal force is suppressed, and the held lubricant does not scatter.

The reason why the shell 12 and the rib 13 can be made thin will be described. The shell portion 12 is originally strong against the compressive force in the axial direction, and is reinforced in the radial direction by the rib 13, so that the shell portion can be made thin. On the contrary, since the outer periphery of the rib 13 is reinforced by the shell portion 12,
The rib 13 can be made thin.

In the present embodiment, the relative movement between the moving block 3 and the guide rail 2 is linear, but the present invention is also applicable to a guide device having a relative movement in a curved manner. .

FIG. 7 shows a spacer 15 according to a second embodiment of the present invention. The spacer 15 of this embodiment also
A shell 12 is disposed such that its axis is substantially coincident with a line connecting the centers of the pair of balls 4, 4 and both ends in the axial direction are in contact with the pair of rolling elements, and a space formed in the shell 12. And a rib 16 integrally formed with the shell portion 12 so as to separate the ribs 16 from each other.

Since the structure of the shell 12 is the same as that of the spacer of the first embodiment, the same reference numerals are given and the description is omitted. In this embodiment, the ribs 16 are formed to have a three-pronged cross section, and are arranged at equal intervals of 120 degrees radially from the axis of the shell portion 12.
a, 16a, 16a. The ribs 16 define three spaces S 1, S 2, S 3 extending in the axial direction in the shell 12 and filled with the lubricant. The rib 16
Are also in contact with the balls 4, 4, and the contact surfaces of the ribs 16 with the balls 4, 4 are also formed into curved surfaces corresponding to the spherical outer peripheral surfaces of the balls 4, 4. The thickness of the rib 16 is formed to be slightly thicker than the spacer 5 of the first embodiment. In this manner, at least three rib components 16a, 16a, 16a in which the ribs 16 are radially arranged.
The shell portion 12 can be reinforced in all radial directions.

FIG. 8 shows a spacer 17 according to the third embodiment of the present invention. The spacer 17 of this embodiment also
A shell 12 is disposed such that its axis is substantially coincident with a line connecting the centers of the pair of balls 4, 4 and both ends in the axial direction are in contact with the pair of rolling elements, and a space formed in the shell 12. And a rib 18 integrally formed with the shell portion 12 so as to separate the shell portion into a plurality. Since the configuration of the shell 12 is the same as that of the spacer 5 of the first embodiment, the same reference numerals are given and the description thereof is omitted. In this embodiment, the rib 18
Are composed of six rib components 18a... Arranged at regular intervals of 60 degrees radially from the axis of the shell 12. The ribs 18 form six spaces S extending in the axial direction in the shell portion 12 and filled with a lubricant.
Both ends in the axial direction of the rib 18 are also in contact with the pair of balls 4, 4, and the contact surface with the balls 4, 4 is also formed into a curved surface corresponding to the spherical outer peripheral surface of the balls 4, 4. Rib 18
Of the spacers 5, 5 of the first and second embodiments.
It is formed slightly thinner than 15.

In this embodiment, the spacer 1
A small-diameter cylindrical space (through hole) 19 is formed on the axis (center line) 7. This cylindrical space is also filled with a lubricant. By forming the space 19 for storing the lubricant on the axis of the spacer 17, the lubricant can be efficiently supplied to the contact portions of the balls 4 and 4 with the rolling grooves.

FIG. 9 shows a spacer 30 according to a fourth embodiment of the present invention. The spacer 30 of this embodiment also
A shell 12 is formed on the line connecting the centers of the pair of balls 4 and 4 such that their axes are substantially coincident with each other, and both ends in the axial direction are formed in the shell 12 and the shell 12. And a rib 31 integrally formed with the shell 12 so as to separate a plurality of spaces. Since the configuration of the shell 12 is the same as that of the spacer of the first embodiment, the same reference numerals are given and the description is omitted. In this embodiment, the ribs 31 are arranged substantially parallel to the axis of the shell 12 and
A pair of rib constituent members 31a vertically dividing the inside into three parts,
31a. The ribs 31 allow the shell 1
2, three spaces S, S, S which extend in the axial direction and are filled with the lubricant are formed. Both ends of the rib 31 in the axial direction are also in contact with the pair of balls 4, 4.
The contact surface is also formed into a curved surface corresponding to the spherical outer peripheral surface of the balls 4 and 4. As shown in this embodiment, as long as the shell 12 can be reinforced and a plurality of spaces S can be formed in the shell 12, the ribs 31 may not be arranged at equal intervals radially from the axis of the shell 12. .

FIG. 10 shows a linear rolling guide device 21 incorporating spacers 20 according to a fifth embodiment of the present invention. The linear rolling guide device 21 includes a guide rail 22 having a roller rolling surface 22a formed on an upper surface and a ball rolling groove 22b formed on a side surface, and a roller rolling groove 23a corresponding to the roller rolling surface 22a. A roller circulation path is formed,
A ball circulation path including a load rolling groove 23b corresponding to the ball rolling groove 22b is formed, and a moving block 23 assembled relative to the guide rail 22 so as to be relatively movable is arranged and accommodated in the roller circulation path. And a plurality of rollers 24 circulating in accordance with the relative movement of the moving block 23 with respect to the guide rail 22, and arranged and accommodated in a ball circulation path,
It is composed of a plurality of rollers 24 circulating in accordance with the relative movement of the moving block 23 with respect to the guide rail 22, and a plurality of spacers 20 interposed between the rollers 24.

The guide rail 22 has a square cross section, and has a roller rolling surface 22a on the upper surface and two upper and lower ball rolling grooves 22b on the left and right side surfaces. The roller rolling surface 22a is a flat horizontal surface, and the ball rolling groove 22b has an arc-shaped cross section.

The moving block 23 has a horizontal portion 26 facing the upper surface of the guide rail 22 and left and right sleeve portions 27 hanging down from the horizontal portion 26 and facing the left and right side surfaces of the guide rail 22. Two roller rolling grooves 23a facing the roller rolling surface 22a are formed on the lower surface of the horizontal portion 26, and two roller rolling grooves 22b facing the two ball rolling grooves 22b are formed on the inner surface of both sleeves 27. A ball rolling groove 23b is formed. Roller rolling groove 2
3a has a rectangular cross section, and rollers 24... Roll on the upper bottom surface of the roller rolling groove 23a. The left and right inner surfaces of the roller rolling groove 23a are parallel to each other and have a slight gap between the roller rolling groove 23a and the end surface of the roller 24. The roller 24 is guided by the left and right inner surfaces of the roller rolling groove 23a. The depth of the roller rolling groove 23a is smaller than that of the roller 24, for example, about half the radius of the roller 24.

A roller load rolling path A is formed between the roller rolling surface 22a of the guide rail 22 and the roller rolling groove 23a of the moving block 23. The moving block 23 has two roller return paths B extending in parallel with each roller load rolling path A, and a U-shaped direction change connecting each roller return path B and the roller load rolling path A. A road C is provided. Roller load rolling path A and roller return path B
And an infinite circulation path for rollers is formed by a combination of a pair of direction change paths C connecting them. In addition, the sleeve 27 of the moving block 23 is formed with two rows of upper and lower balls infinite circulation paths in accordance with the upper and lower rows of balls 25.

As shown in FIG. 10, as the moving block 23 moves along the guide rail 22,
4 roll on the load rolling path A from one end to the other end while receiving the load from the moving block 23, and then are scooped up on one of the direction changing paths C and guided to the return path B, and further opposite. Is returned to one end of the load rolling path A via the side turning path C. Here, on the load rolling path A in the load area, the rollers 24 roll while receiving a load, and on the direction change path C and the return path B in the no-load area, the rollers 24 circulate without receiving a load. In the linear rolling guide device of the present embodiment, the spacer 45 turns two-dimensionally during the circulation of the roller 24 described above. That is, the linear load rolling path A⇒U
The direction is changed on a U-shaped turning path C → a straight return path B → U-shaped turning path C.

A plurality of spacers 20 are interposed between the plurality of rollers 24 arranged and accommodated in the endless circulation path. FIGS. 11 and 12 show the spacer 20 incorporated in the linear rolling guide device 21. The spacer 20 is made of synthetic resin or the like, and is formed by injection molding or the like. Each spacer 20 is interposed between a pair of rollers 24,24.

The spacer 20 includes a pair of rollers 24, 24.
A shell 28 arranged so that its axis substantially coincides with a line connecting the centers of the rollers (the center point in the longitudinal direction of the roller axis), and both ends in the axial direction contacting the pair of rollers 24, 24;
A rib is integrally formed with the shell so as to separate a plurality of spaces formed in the shell. Shell 28
Is formed in a substantially rectangular frame shape, and a cross section orthogonal to the axis is formed in a thin rectangular shape having a constant cross-sectional area. The contact surfaces 28a, 28a with the pair of rollers 24, 24 at both ends of the shell 28 are curved surfaces corresponding to the cylindrical outer peripheral surfaces of the rollers 24, 24 so that the rollers 24, 24 fit into the spacers 20. Is formed. As the rollers 24, 24 slide on the contact surfaces 28a, 28a,
a, 28a support the rotational movement of the rollers 24,24.
The length of the shell 28 in the axial direction of the roller 24 is adjusted so that the rotational movement of the roller 24 can be stably supported.
4 is set slightly smaller than the length in the axial direction. The height of the shell 28 is set to a value equal to the roller diameter 7 so that the shell 28 does not collide with the wall surface constituting the infinite circulation path in the infinite circulation path.
It is set to about 0%. The length of the shell 28 in the traveling direction is set to be thin so that the distance between the pair of rollers 24, 24 is shortened.

The rib 29 is formed integrally with the shell 28 so as to separate a plurality of spaces formed in the shell 28. In this embodiment, the rib 29 is formed in a cross shape so as to connect diagonal lines of the shell portion 28, and is composed of four rib components 29a... Arranged radially from the axis of the shell portion 28. The ribs 29 form a plurality (four) of spaces S extending in the axial direction in the shell portion 28 and filled with a lubricant. Both ends of the rib 29 in the axial direction also contact the outer peripheral surfaces of the pair of rollers 24, 24, and the contact surfaces 29b of the rib 29 with the rollers 24 also have curved surfaces corresponding to the outer peripheral surfaces of the cylindrical rollers 24, 24. Is formed. The thickness of the rib 29 is set such that the spacer 20 has sufficient strength against a load applied in the radial direction and that a large amount of lubricant can be stored inside the spacer 20.

When the spacer 20 is configured as described above,
Since a large amount of lubricant such as grease can be held in the plurality of spaces S formed in the shell portion 28, the spacer 20 having excellent lubricant holding ability can be obtained. Further, the scattering of the lubricant can be prevented by the shell portion 28 constituting the outer periphery of the spacer 20, and the lubricant can be held for a long period of time, so that the ability to hold the lubricant is improved. Further, since the shell 28 has a structure reinforced by the rib 29, the shell 28 and the rib 29 are made thinner and the spacer 20 is formed.
Can be made lighter overall. Therefore, the followability of the spacers 20 to the rollers 24 can be improved, and the centrifugal force applied to the spacers 20 in the direction change path can be minimized. As a result, jumping (bias) to the outside of the direction change road due to centrifugal force is suppressed,
The retained lubricant is not scattered.

Although not shown, in order to prevent the spacers 20 from moving in the axial direction of the rollers 24, a projecting plate is provided on the upper surface or the lower surface of the spacers 20, so that the roller endless circulation path is formed. A guide groove into which the projection plate of the spacer 20... May be formed on the inner peripheral side or the outer peripheral side. The spacers 20 have the same effect as the spacers 20 of the third embodiment, and the spacers 20
.. Move along the fixed path defined by the guide groove 43, so that the rollers 24 held by the spacers 20 do not meander in the fixed path for rollers. Circulates orderly. In particular, since the spacers 20 do not meander in the axial direction of the rollers 24, the end faces of the spacers 20 in the axial direction can be prevented from hitting the walls of the roller endless circulation path.

FIGS. 13 and 14 show a spacer 45 according to a sixth embodiment incorporated in the linear rolling guide device. Similarly to the spacer 20 of the fifth embodiment, the axis of the spacer 45 substantially coincides with the line connecting the centers of the pair of rollers 24, 24 (the center point in the longitudinal direction of the axes of the rollers 24, 24). And a shell portion 2 having both ends in the axial direction contacting the pair of rollers 24, 24, and a shell portion 2 formed so as to separate a plurality of spaces formed in the shell portion 28 from each other.
8 and a rib 36 integrally formed. The shell 28 is
Since the configuration is the same as that of the spacer of the fifth embodiment, the same reference numerals are given and the description is omitted.

The rib 36 is formed integrally with the shell so as to separate a plurality of spaces formed in the shell 28. In this embodiment, the rib 36 has two rib components 36 formed so as to be substantially parallel to the side surface 28 b of the shell 28.
a, 36a. The ribs 36 form three spaces S extending in the axial direction and filled with the lubricant in the shell portion 28. Both ends of the rib 36 in the axial direction also contact the outer peripheral surfaces of the pair of rollers 24, 24, and the contact surfaces 36b, 36b with the rollers 24, 24 are also curved surfaces corresponding to the outer peripheral surfaces of the cylindrical rollers 24, 24. Is formed.

FIGS. 15 and 16 show a ball screw 50 incorporating the spacer 5 according to the first embodiment of the present invention. The ball screw 50 includes a screw shaft 51 (orbital axis) having a helical ball rolling groove 51a as a rolling element rolling surface on the outer peripheral surface, and the ball rolling groove 5 on the inner peripheral surface.
A ball circulation path (rolling body circulation path) including a spiral load rolling groove 52a as a load rolling surface corresponding to 1a is formed, and a nut member 52 ( And a plurality of balls 53 as rolling elements that are arranged and housed in the ball circulation path and circulate in accordance with the relative movement (rotation) of the screw shaft 51 and the nut member 52. A ball rolling groove 51a of the screw shaft 51;
The load rolling path of the ball circulation path is formed between the nut member 52 and the load rolling groove 52a.

Ball rolling groove 51 provided on screw shaft 51
“a” has a cross-sectional shape of, for example, an arc, and is formed by grinding or rolling.

As shown in FIG. 15, the main body of the nut member 52 has a substantially cylindrical shape, and has a flange 55 at an end thereof for coupling with a mating component. The main body of the nut member 52 has a flat portion 6 formed by flattening a part of the outer peripheral portion.
0 is formed. In the flat portion 60, four return pipe fitting holes 61 into which both sides of the return pipe 56 are inserted are provided.
Can be opened in places. The return pipe fitting hole 61 extends into the load rolling groove 52a.

The nut member 52 has two return pipes 56. The return pipe 56 forms a no-load return passage connecting one end and the other end of the load rolling path. The return pipe 56 has a circular cross section, and both ends are bent by about 90 ° with respect to the main body. That is, the return pipe 56 is formed in a substantially gate-like shape including a pair of legs 56a and 56b and a horizontal portion 56c (see FIG. 16). Return pipe 56
Are inserted into the load rolling path at intervals of several pitches. Further, the return pipe 56 is fixed to the nut member main body by the pipe retainer 54 (see FIG. 15).

FIG. 16 shows the balls 53 and the spacers 5 to be filled in the load rolling path and the return pipe 56. However, in this drawing, the spacer 5 shows only a portion having a cross section and a part interposed between the balls 53.
Other spacers are omitted. The spacer 5 is a ball 5
3 are arranged every other one, and hold the balls 53.
Here, if the both end surfaces of the spacer 5 are formed such that the spacers 5 and the balls 53 are arranged in a substantially annular shape, no excessive force acts on the spacers 5 and the balls 53 in the ball circulation path.

When the screw shaft 51 is rotated, the ball 53 which rolls in the circumferential direction while receiving a load in the ball rolling groove 51a.
Are scooped up at the tip of the leg 56a. The scooped balls 53 pass through the return pipe 56. Then, the balls 53 are returned to the ball rolling grooves 51a again from the legs 56b separated by several pitches. When the rotation direction of the screw shaft 51 is reversed, the balls 53 circulate along the reverse path. In addition, when the nut member 52 is rotated with the screw shaft 51 as the fixed side, the circulation is similarly performed.

The load rolling path of the ball screw 50 is formed spirally as described above, and the return pipe 56 changes the direction of the scooped ball 53. In the ball screw 50, the ball 53 and the spacer 5 turn three-dimensionally and move in a complicated manner.

In the example of the present ball screw 50, the balls 53, which roll in the ball rolling grooves 51a of the screw shaft 51, are scooped up using the return pipe 56 and returned by several turns.
In addition, there is a configuration in which a deflector for scooping up the balls 53 is provided on the nut member 52. That is, the screw shaft 5
The ball 53 that has rolled on the first ball rolling groove 51a ...
Is separated from the ball rolling groove 51a by the deflector, jumps over the outer diameter portion of the screw shaft 51, and returns to the ball rolling groove 51a one lead before. Although not shown, the nut member 52 is composed of a nut main body having a ball rolling groove 51a formed therein and side covers mounted on both ends of the nut main body. A so-called side cover type ball screw formed with the ball rolling groove 51a and the return passage communicating with each other on both sides of the cover can also be adopted.

Further, the spacer according to the present invention is not limited to a linear rolling guide device and a ball screw, but can also be used for a ball spline device. Here, the ball spline device refers to a device having a spline shaft as a track member and an outer cylinder as a slide member movably attached to the spline shaft via a number of balls.

[0061]

As described above, according to the present invention,
A spacer interposed between the rolling elements is arranged so that an axis thereof substantially coincides with a line connecting the centers of the rolling elements, and a spacer in which both ends in the axial direction contact the rolling elements separates a space in the shell. And a rib integrally formed with the shell portion, and a plurality of spaces extending in the axial direction are formed in the shell portion, so that a lot of lubricant such as grease is held in the plurality of spaces formed in the shell portion. And a spacer having excellent lubricant holding ability can be obtained. Also, the scattering of the lubricant can be prevented by the shell constituting the outer periphery of the spacer,
Since the lubricant can be held for a long period of time, the ability to hold the lubricant is improved in this respect as well. Further, since the shell portion is reinforced with the rib, the shell portion and the rib can be made thinner, and the spacer can be made lighter as a whole. Therefore, the followability of the spacer with respect to the rolling elements can be improved, and the centrifugal force applied to the spacer in the direction change path is minimized. Lubricant does not scatter.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a linear rolling guide device incorporating a spacer according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view in a direction perpendicular to the guide rails of the linear rolling guide device incorporating the spacer according to the first embodiment of the present invention;

FIG. 3 is a cross-sectional view along a rail axis direction showing a ball circulating in a ball circulation path of the linear rolling guide device incorporating the spacer according to the first embodiment of the present invention.

FIG. 4 is a sectional view showing a spacer and a ball according to the first embodiment of the present invention.

FIG. 5 is a side view showing the spacer according to the first embodiment of the present invention.

FIG. 6 is a sectional view showing a spacer according to the first embodiment of the present invention.

FIG. 7 is a sectional view showing a spacer and a ball according to a second embodiment of the present invention.

FIG. 8 is a sectional view showing a spacer and a ball according to a third embodiment of the present invention.

FIG. 9 is a sectional view showing a spacer and a ball according to a fourth embodiment of the present invention.

FIG. 10 is a perspective view showing a linear rolling guide device incorporating a spacer according to a fifth embodiment of the present invention.

FIG. 11 is a perspective view showing a spacer and a ball according to a fifth embodiment of the present invention.

FIG. 12 is a sectional view showing a spacer and a ball according to a fifth embodiment of the present invention.

FIG. 13 is a perspective view showing a spacer and a ball according to a sixth embodiment of the present invention.

FIG. 14 is a sectional view showing a spacer and a ball according to a sixth embodiment of the present invention.

FIG. 15 is a perspective view showing a ball screw incorporating the spacer according to the first embodiment of the present invention.

16 is a side view showing a return pipe, a screw shaft, and a ball, which are main parts of the ball screw shown in FIG.

FIG. 17 is a side view showing a conventional spacer.

FIG. 18 is a side view showing another conventional spacer.

[Explanation of symbols]

2 Guide rail (track axis) 2a, 2b Ball rolling groove (rolling element rolling surface) 3 Slide member 3a, 3b Load rolling groove (load rolling surface) 4 ... Ball (rolling element) 5, 15, 17, 20, 30, 35 Spacer for linear motion device 12, 28 Shell 13, 16, 18, 31, 29, 36 Rib 13a, 16a, 18a, 31a, 29a, 36a Rib component 19, S space

Continued on front page F-term (reference) 3J101 AA02 AA13 AA33 AA44 AA52 AA64 AA65 BA13 CA14 EA63 FA15 FA32 FA51 FA53 3J104 AA03 AA23 AA25 AA36 AA37 AA57 AA63 AA65 AA69 AA74 AA75 AA76 BA80 CA06 DA12

Claims (7)

[Claims] 1. A spacer for a linear motion device interposed between a plurality of rolling elements arranged and housed in an infinite circulation path of the linear motion device, wherein an axis is substantially a line connecting the centers of a pair of rolling elements. A shell portion arranged so as to coincide with each other and both ends in the axial direction contacting the pair of rolling elements; and a rib integrally formed with the shell portion so as to separate a space formed in the shell portion. Wherein the space penetrates the shell in the axial direction. 2. A spacer for a linear motion device, wherein both ends of the rib in the axial direction are also in contact with the pair of rolling elements. 3. A spacer for a linear motion device, wherein a contact surface of the shell and the rib with the pair of rolling elements is formed as a curved surface corresponding to an outer peripheral surface of the pair of rolling elements. . 4. The at least three ribs are radially spaced from the axis of the shell toward the shell.
The linear motion device spacer according to any one of claims 1 to 3, wherein the spacer is constituted by three rib components. 5. The spacer for a linear motion device according to claim 1, wherein the shell portion is formed in a cylindrical or rectangular frame shape having a constant cross-sectional area in the axial direction. 6. The spacer for a linear motion device according to claim 1, wherein one of the plurality of spaces is formed on an axis of the shell. 7. A raceway shaft having a rolling element rolling surface, and a rolling element circulation path including a load rolling surface corresponding to the rolling element rolling surface, and are mounted on the raceway shaft so as to be relatively movable. Slide member, arranged and housed in the rolling element circulation path,
A linear motion device comprising: a plurality of rolling elements circulating in accordance with the relative motion of the slide member with respect to the track axis; and a plurality of linear motion device spacers interposed between the plurality of rolling elements. The spacer is arranged so that an axis thereof substantially coincides with a line connecting the centers of the rolling elements, and is integral with the shell so that both ends in the axial direction are in contact with the rolling elements, and a space in the shell is separated. A linear motion device comprising: a molded rib; and the plurality of spaces penetrate the shell in an axial direction.