JP2009127740A - Linear motion guidance device - Google Patents

Abstract

An end portion of a belt portion is prevented from being strongly rubbed against a guide groove formed in a direction change path even when an end separator is used.
A guide groove 50 for guiding a belt portion 42 of a separator 4 includes an arc portion 5 formed in an arcuate direction change path 24 and a linear portion 6 continuous therewith. The center C ₁ of the first arc 51 that forms the outer peripheral surface of the arc portion 5 of the guide groove 50 is arranged closer to the outer peripheral surface side of the direction changing path 24 than the center C ₀ of the reference arc of the direction changing path 24. The width (width along the straight line S passing through the center points C ₀ , C ₁ , C ₂ ) W ₁ at the deepest position (circulation R bottom) of the direction change path 24 of the arc portion 5 of the guide groove 50 is defined as a straight line. It is made wider than the width W _{0 of the} part.
[Selection] Figure 1

Description

  The present invention relates to a linear motion guide device provided with an end separator.

  The linear motion guide device includes a guide rail, a slider, and a plurality of rolling elements, the rolling surfaces of the rolling element are formed on both side surfaces in the width direction of the guide rail, and the sliders are disposed on both sides in the width direction of the guide rail. And a trunk portion that is arranged on one end side in the thickness direction of the guide rail and connects the both leg portions. A rolling surface of the rolling element is formed on the inner side surfaces of the both leg portions so as to face the rolling surface of the guide rail, and the rolling surface and the rolling surface of the guide rail form a rolling path. ing. Further, a return passage for the rolling element is formed in the both leg portions, and further, as a direction changing passage for communicating the return passage and the rolling passage, an outer peripheral surface is formed by an arc-shaped recess, and an inner peripheral surface is formed by an arc. An arc-shaped passage made of a convex portion is formed. The rolling path, the return path, and the direction changing path constitute a circulation path of the rolling element, and the rolling element moves in the circulation path, so that one of the guide rail and the slider is relative to the other. Move directly.

Provided with an end separator having a spacer portion disposed between adjacent rolling elements and a belt portion that is fixed at each position on the opposite side across the spacer portion and connects the spacer portions. As a conventional example of the linear motion guide device, there are those described in Patent Document 1 and Patent Document 2 below.
In Patent Literature 1, an end rolling element chain (an end-shaped chain) in which an interposition part (spacer part) interposed in a rolling element is connected by a flexible resin coupling body (belt part) having both ends. A separator) is incorporated in the endless track (circulation path), and a gap is formed between both ends of the rolling element chain facing each other in the endless track. In FIG. 1 of this example, the guide groove for guiding the belt portion on the direction change path seems to be the same as the locus of the center of the ball (rolling element).

In Patent Document 2, a guide groove for guiding the belt portion is provided so that the trajectory of the belt portion on the direction change path is shifted to the inner peripheral side of the direction change path from the center trajectory of the ball (rolling body). By forming a sufficient gap between the rolling elements that pass through the direction change path and the spacer, the lubricant is efficiently taken in from the direction change path and rolls on the load rolling path (rolling path). It describes smooth lubrication of rolling elements (rolling).
Japanese Patent No. 3243415 FIG. Japanese Patent Laid-Open No. 11-247854

  However, in both cases of Patent Documents 1 and 2, since the rolling elements are present before and after sandwiching the spacer portion at portions other than both ends of the belt portion, the belt portion is easily bent along the direction change path. On the other hand, since there are no rolling elements between the spacers at the end of the belt portion, the end of the belt portion is unlikely to bend along the direction change path. As a result, the end of the belt portion is strongly rubbed against the belt guide groove in the direction change path, and the frictional force may increase.

Since endless separators have rolling elements before and after sandwiching all spacers, the belt part easily bends in the direction change path, and the frictional force increase as described above does not occur. Since connecting work is necessary, there is a problem in productivity.
The present invention has been made paying attention to such problems of the prior art, and the end of the belt portion is rubbed strongly against the guide groove formed in the direction change path even when the end separator is used. The challenge is to avoid it.

  In order to solve the above problems, the present invention is composed of a guide rail, a slider, a plurality of rolling elements, and an end separator, and the rolling surfaces of the rolling elements are formed on both sides in the width direction of the guide rail. The slider is composed of leg portions disposed on both sides in the width direction of the guide rail and a body portion that is disposed on one end side in the thickness direction of the guide rail and connects the both leg portions. A rolling surface is provided opposite to the rolling surface of the guide rail, and a rolling path of the rolling element is formed by the rolling surface and the rolling surface of the guide rail, and the return path of the rolling body is formed in the both legs. The leg portions are also arc-shaped with an outer peripheral surface made of an arc-shaped concave portion and an inner peripheral surface made of an arc-shaped convex portion as a direction changing path for communicating the return passage and the rolling passage. The rolling element is formed by the rolling path, the return path, and the direction changing path. A circulation path is configured, and the separator includes a spacer portion disposed between adjacent rolling elements, and a belt portion that is fixed at each position on the opposite side across the spacer portion and connects the spacer portions. A guide groove formed of an arc portion formed in an arc-shaped direction change path that guides the belt portion along the circulation path and a linear portion continuous therewith is formed, and the guide groove is formed along the guide groove. A belt part is guided in the circulation path (that is, the belt part has elasticity capable of bending along an arc-shaped guide groove formed in the direction change path), and a rolling element is moved in the circulation path. In the linear motion guide device in which one of the guide rail and the slider moves linearly relative to the other by moving, the center of the first circular arc that forms the outer peripheral surface of the arc portion is the outer peripheral surface of the direction change path. The outer peripheral surface of the direction change path from the center of the reference arc Are arranged, the width at the deepest position in the direction changing passage of the arc portion of the guide groove (circulation R bottom) provides a linear guide device, characterized in that it is wider than the width of the linear portion.

In the linear guide device, for example, the center C ₁ of the first arc forming the outer peripheral surface of the guide groove formed in the direction change path is more outer than the center C _{0 of the} reference arc of the direction change path. The center C ₂ of the second arc that is arranged on the surface side and forms the inner peripheral surface of the guide groove on the direction change path is the same position as the center C ₀ of the reference arc, or the first arc across the center C _{0 of the} reference arc. Compared to the case where all of the centers are the same (C ₁ = C ₀ = C ₂ ), the outer peripheral surface of the guide groove is on the outside when arranged on the opposite side of the center C ₁ of one arc (FIG. 1). The inner circumferential surface of the guide groove moves the same or inward.

Thereby, the width | variety of the circular arc part formed in the direction change path of a guide groove is formed more widely than the width | variety of the guide groove of the linear part which continues to this. As a result, the guide groove is formed such that the width (W ₁ in FIG. 1 and W 2 in FIG. ₂ ) at the deepest position of the direction change path of the arc portion is wider than the width of the straight portion.
In the case of C ₀ = C ₂ , it is formed so as to swell outward, and in the order of C ₁ , C ₀ , C ₂ from the side close to the outer peripheral surface of the direction change path, it swells outward and also expands inward. Formed as follows. For this reason, when C ₁ = C ₀ = C ₂ and the end closer to the outer peripheral surface of the direction change path, C ₁ = C ₀ , C ₂ , compared with the order of the end separator, the direction change path is The rubbing of the end portion of the belt portion with respect to the guide groove is eased.

  According to the linear motion guide device of the present invention, it is possible to prevent the end portion of the belt portion from being rubbed strongly against the belt guide groove formed in the direction changing path while using the end-like separator.

Hereinafter, embodiments of the present invention will be described.
FIG. 1 is a partial cross-sectional view showing the linear motion guide device of this embodiment. This linear motion guide device includes a guide rail 1, a slider 2, a plurality of balls (rolling elements) 3, and an end separator 4. Rolling grooves (rolling surfaces) 11 for the balls 3 are formed on both side surfaces of the guide rail 1 in the width direction.

  The slider 2 includes a main body 21 and end caps 22 fixed to both ends of the linear movement direction. The slider 2 has a trunk portion (illustrated in the figure) in which leg portions (one leg portion is shown) arranged on both sides in the width direction of the guide rail 1 are arranged on one end side in the thickness direction of the guide rail 1. Not connected). And it has the rolling groove 21A arrange | positioned facing the rolling groove 11 of the guide rail 1 in the inner surface of both the leg parts of the main body 21, and the rolling channel | path of the ball | bowl 3 is formed by both rolling grooves 11 and 21A. ing.

  Further, return paths 23 for the balls 3 are formed on both legs, and the outer peripheral surface 24a is formed of an arcuate recess as a direction changing path 24 that connects the return path 23 and the rolling path to both legs. The surface 24b is formed with an arcuate passage formed of an arcuate convex portion. These rolling passages (passage formed by both rolling grooves 11 and 21A), the return passage 23, and the direction changing passage 24 constitute a circulation path of the ball 3.

  The separator 4 includes a spacer portion 41 disposed between adjacent balls 3 and a belt portion 42 that connects the spacer portions 41. The belt portion 42 is on the opposite side across the spacer portion 41. Placed in position. The separator 4 is integrally formed with a spacer portion 41 and a belt portion 42 by injection molding using a synthetic resin. The belt portion 42 has elasticity that can be bent along an arc portion 5 of a guide groove 50 described later. The spacer portions 41 a at both ends have a flat surface that does not hold the ball 3, and the other spacer portions 41 have a spherical surface that can hold the ball 3 on the opposite surface. The spacer 41 has a shape in which the holding amount on the inner peripheral surface side in the circulation path is smaller than the holding amount on the outer peripheral surface side.

A guide groove 50 for guiding the belt portion 42 of the separator 4 is formed in the circulation path. The guide groove 50 includes an arc portion 5 formed in the arc-shaped direction change path 24 and a linear portion 6 continuous therewith. The center C ₁ of the first arc 51 that forms the outer peripheral surface of the arc portion 5 of the guide groove 50 is disposed closer to the outer peripheral surface side of the direction changing path 24 than the center C ₀ of the reference arc of the direction changing path 24. The center C ₂ of the second arc forming the inner peripheral surface 52 of the arc portion 5 is disposed on the opposite side of the center C ₁ of the first arc across the center C _{0 of the} reference arc.

Therefore, as shown in FIG. 2, the center C _{1 of} the first arc 51 a (broken line in FIG. 2) forming the outer peripheral surface of the arc portion 5 of the guide groove 50 is the same as the center C ₀ of the reference arc of the direction change path 24. In comparison with FIG. 2, the outer peripheral surface 51 (solid line in FIG. 2) of the arc portion 5 moves outward, and the arc portion 5 of the guide groove 50 swells outward. As a result, the guide groove 50 has a width (width along the straight line S passing through the center points C ₀ , C ₁ , C ₂ ) W ₁ at the deepest position of the direction change path 24 of the arc portion 5 of the straight portion. It becomes wider than the width W ₀ . Therefore, when the end-like separator 4 is incorporated, the rubbing of the end portion (the portion indicated by a circle in FIG. 2) of the belt portion 42 (the broken belt portion 42a) with respect to the arc portion 5 of the guide groove 50 is alleviated. .

Symbol K ₀ indicates the locus of the center of the ball (rolling element) 3 in the circulation path, and it can be seen that the guide groove 50 of the belt portion 42 is formed at a position shifted to the inner circumference side in the circulation path. Further, in this embodiment, the belt portion 42 is formed in the spacer 41 by the shape of the holding amount on the inner peripheral surface side of the circulation path of the spacer portion 41 being smaller than the holding amount on the outer peripheral surface side. Pulling in the circumferential side is alleviated, and rubbing of the end portion of the belt portion 42 against the guide groove 50 (arc portion 5) in the direction changing path 24 is alleviated.

Further, the arc portion 5A of the guide groove 50A in FIG. 2 is formed by a first arc 51a that forms the outer peripheral surface and a second arc 52 that forms the inner peripheral surface, and the center of the second arc 52 is C ₂ as in FIG. is there. That is, the center C ₂ of the center C ₁ and the second arc 52 of first arc 51a of an arc section 5A of the guide groove 50A of FIG. 2 (dashed line) (solid line), C from the side closer to the outer circumferential surface of the direction changing passage _{Since 1} = C ₀ and C ₂ are arranged in this order, the width of the arc portion 5A of the guide groove 50A is wider than that of C ₁ = C ₀ = C ₂ and the direction change path 24 of the arc portion 5A is the largest. The width at the deep position (the center point C ₀ = the width along the straight line S passing through C ₁ and C ₂ ) W ₂ becomes wider than the width W _{0 of the} straight line portion.

Note that, as the width of the arc portion 5 of the guide groove 50 increases, the restraining force of the ball (rolling element) 3 on the direction change path 24 becomes weaker, so the center C of the reference arc of the center C ₁ of the first arc 51 ₀ the shift amount L ₂ from the shift amount L ₁ and the center C ₀ of the reference arc the center C ₂ of the second arc 52 from is limited. The maximum allowable values of these shift amounts L ₁ and L ₂ vary depending on the size of the direction change path 24 (the size of the arc that forms the outer peripheral surface and the inner peripheral surface, the width of the direction change path 24), but the guide groove 50 From the viewpoint of suppressing the amount of rubbing of the end portion of the belt portion 42 with respect to the arc portion 5 and ensuring the restraining force of the rolling element, it is preferable that the diameter is 20% or less of the rolling element diameter.

It is a fragmentary sectional view which shows the linear motion guide apparatus of embodiment of this invention. It is a fragmentary sectional view of the linear guide device explaining the effect of the embodiment of the present invention by comparison with the conventional example.

Explanation of symbols

1 Guide rail 11 Rolling groove (rolling surface) of guide rail
2 Slider 21 Slider body 21A Slider rolling groove (rolling surface)
22 End cap of slider 23 Return passage 24 Direction change path 24a Outer peripheral surface of direction change path 24b Inner peripheral surface of direction change path 3 Ball (rolling element)
4 Separator 41 Spacer 41a Spacer on both ends of separator 42 Belt part 42a Belt part 5 Arc part of guide groove 5A Arc part of guide groove 50 Guide groove 50A Guide groove 51 Outer peripheral surface of arc part (first arc)
51a Outer peripheral surface of the arc part (first arc)
52 Inner circumferential surface of arc part (second arc)
Center of reference arc of C ₀ direction change path C ₁ Center of first arc C ₂ Center of second arc W ₀ Width of straight portion of guide groove W ₁ Circulation of guide groove R Width at bottom of bottom W ₂ Circulation of guide groove R bottom width

Claims (1)

Consists of a guide rail, a slider, a plurality of rolling elements and an end separator,
Rolling surfaces of the rolling elements are formed on both sides in the width direction of the guide rail,
The slider is composed of leg portions disposed on both sides in the width direction of the guide rail and a body portion that is disposed on one end side in the thickness direction of the guide rail and connects the both leg portions.
The inner surface of the both legs has a rolling surface disposed opposite to the rolling surface of the guide rail, and the rolling surface of the rolling element is formed by the rolling surface and the rolling surface of the guide rail, Both leg portions are formed with return passages for rolling elements, and both leg portions also have arc-shaped concave portions on the outer peripheral surface as circular turning paths, and the inner peripheral surface is a circular path as a direction changing path for communicating the return passage and the rolling passage. An arc-shaped passage composed of arc-shaped convex portions is formed,
The rolling path, the return path, and the direction changing path constitute a circulation path of the rolling elements,
The separator includes a spacer portion disposed between adjacent rolling elements, and a belt portion that is fixed to each position on the opposite side across the spacer portion and connects the spacer portions,
A guide groove is formed which includes an arc portion formed in an arc-shaped direction changing path that guides the belt portion along the circulation path, and a linear portion continuous therewith,
A linear motion in which one of the guide rail and the slider linearly moves relative to the other when the belt portion is guided in the circulation path along the guide groove and the rolling element moves in the circulation path. In the guidance device,
The center of the first arc that forms the outer peripheral surface of the arc portion is disposed closer to the outer peripheral surface of the direction changing path than the center of the reference arc that forms the outer peripheral surface of the direction changing path, and the direction changing path of the arc portion of the guide groove The linear guide device is characterized in that the width at the deepest position is wider than the width of the straight portion.

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