JP2010078037A - Motion guide device and retainer used therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a retainer having sufficient strength against an alternating load of repeating pulling/relaxation even when forming a connecting part only on one side of spacer parts, and a motion guide device having its retainer. <P>SOLUTION: This motion guide device has a plurality of spacer parts interposed between rolling elements and the retainer having the connecting part for connecting one end of the mutual spacer parts only on one side of the spacer parts. The connecting part has a projection part projecting in the direction for crossing with the extension direction of the connecting part, in an end part on the opposite side of the connecting end with the spacer parts. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a motion guide device in which a guide shaft and a moving member are engaged via a rolling element and a retainer used therefor, and more specifically, an infinite circulation path in which the rolling element performs a three-dimensional motion. Even if formed, the motion guide device does not increase in size, and the invention relates to a motion guide device including a retainer having strength against an alternating load accompanying rolling of a rolling element and a retainer used therefor.

  In a work table of a machine tool and a linear guide portion of various conveying devices, a linear guide device in which a moving member mounted with a movable body such as a table continuously moves along a guide axis is frequently used. In this type of linear guide device, the moving member is assembled to the guide shaft via a plurality of rolling elements, and the rolling element rolls while applying a load between the moving member and the guide shaft, The movable body mounted on the moving member can be moved lightly with a slight resistance along the guide shaft. Further, the moving member is formed with an infinite circulation path of the rolling elements, and the moving member can continuously move along the guide shaft by circulating the rolling elements in the infinite circulation path. ing.

  As such a conventional motion guide device, as described in the following Patent Document 1, the occurrence of foreign matter and abnormal noise due to contact between adjacent rolling elements accompanying the rolling of the rolling elements is prevented. In order to achieve smooth circulation of the rolling elements, a motion guide device provided with a retainer having a spacer part interposed between the rolling elements and connecting parts respectively connecting both sides of the spacer part It has been known.

Japanese Patent Laid-Open No. 9-229064

  However, according to the motion guide device described in Patent Document 1 described above, the retainer used in such a motion guide device is used in a device in which the rolling element moves two-dimensionally, such as a linear guide device. Since the retainer connecting portion only needs to bend in the thickness direction, that is, along the contact angle line of the rolling element, there is no particular problem even with a retainer having a connecting portion connecting both sides of the spacer portion. Since a device that moves three-dimensionally like a device needs to be deformed in a direction that intersects the contact angle line, such as a twisting direction, the connecting portion that connects both sides of the spacer portion. There was a problem that a retainer provided with the inability to apply. Further, in the ball spline device, as described above, it is possible to form an infinite circuit so as not to perform the three-dimensional motion of the rolling elements. Further, since the bending direction of the connecting portion is the radial direction of the outer cylinder constituting the moving member, there is a problem that the outer dimension of the outer cylinder is increased and the ball spline device is enlarged.

  A retainer in which a connecting portion is provided only on one side of a spacer as described in FIG. 8 of Patent Document 1 is also known, but as described in Patent Document 1, a connecting portion is provided. If it is formed only on one side, there is a problem that it is disadvantageous in strength in order to continuously receive an alternating load in which the connecting portion is repeatedly pulled and relaxed as the rolling element rolls.

  The present invention has been made to solve the above-described problems, and can be applied to a ball spline device or the like in which a rolling element performs a three-dimensional motion without enlarging the size of the constituent members. The present invention provides a retainer having sufficient strength against an alternating load in which tension and relaxation are repeated even when the connecting portion is formed only on one side of the spacer portion, and a motion guide device including the retainer.

  The motion guide device according to the present invention that solves the above-described problems includes a guide shaft having a rolling element rolling surface formed along a longitudinal direction, and the load rolling element rolling path together with the rolling element rolling surface. A moving member in which a loaded rolling element rolling surface and an unloaded rolling element rolling path formed so as to face the rolling element rolling surface are formed so as to be relatively movable with the guide shaft, and the loaded rolling element rolling path And a plurality of rolling elements arranged in an infinite circulation path including the unloaded rolling element rolling path and circulated in accordance with relative movement of the guide shaft and the moving member, and between the rolling elements A plurality of spacers interposed between the spacers and a retainer provided on one side of the spacers to connect the ends of the spacers to each other; Intersects the extending direction of the connecting portion at the end opposite to the connecting end of It characterized by having a projection portion projecting that direction.

  In the motion guide device according to the present invention, the protrusion may protrude symmetrically with respect to the connecting portion.

  In the motion guide device according to the present invention, the protrusion may be engaged with a retainer holding groove formed along at least the load rolling element rolling surface.

  Moreover, the retainer which concerns on this invention equips only one side of the said spacer part with the connection part which connects the some spacer part interposed between rolling elements, and the one end of the said spacer parts, The said connection part Has a protruding portion that protrudes in a direction intersecting the extending direction of the connecting portion at the end opposite to the connecting end with the spacer portion.

  According to the present invention, since the protruding portion is formed in the connecting portion of the retainer, the protruding portion serves as a reinforcement and can be applied to a ball spline device or the like in which the rolling element moves three-dimensionally. In the case where the connecting portion is formed at one end of one side of the spacer portion, it is possible to have sufficient strength against an alternating load in which tension and relaxation are repeated.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments for carrying out the invention will be described with reference to the drawings. The following embodiments do not limit the invention according to each claim, and all combinations of features described in each embodiment are essential to the solution means of the invention. Not exclusively. In the following embodiments, a ball spline will be described as an example of a motion guide device. However, the motion guide device is not limited to a ball spline, and can be applied to a linear guide or the like. It is clear from the description of the range.

[First Embodiment]
FIG. 1 is an external perspective view of the motion guide apparatus according to the first embodiment. Furthermore, FIG. 2 is sectional drawing for demonstrating the load rolling path and unloaded rolling path of the exercise | movement guide apparatus which concern on 1st Embodiment. FIG. 3 is a partial cross-sectional view for explaining the internal structure of the motion guide apparatus according to the first embodiment. FIG. 4 is an exploded view for explaining the internal structure of the motion guide apparatus according to the first embodiment. Furthermore, FIG. 5 is a figure which shows the rolling element and retainer of the exercise | movement guide apparatus which concern on 1st Embodiment.

  The motion guide device according to the first embodiment described in FIG. 1 is configured as a ball spline device 1. The ball spline device 1 according to the first embodiment includes a guide shaft 2 having a rolling element rolling surface 21 formed on the outer peripheral surface along the longitudinal direction, and the guide shaft via a plurality of rolling elements 4. 2 and a moving member 3 that linearly moves around the guide shaft 2 along the rolling element rolling surface 21.

  As shown in FIG. 1, the guide shaft 2 is a member in which four rolling element rolling surfaces 21 extending in the longitudinal direction are formed on the surface, and the rolling element rolling surface 21 includes a moving member 3 described later. It is possible to receive a load from the spherical rolling elements 4 disposed between the two. Moreover, this rolling element rolling surface 21 is formed in the circular arc shape with the precision which can implement | achieve smooth rolling of the rolling element 4. FIG.

  A cylindrical moving member 3 that moves linearly around the guide shaft 2 is assembled to the guide shaft 2.

  As shown in FIG. 2, a load rolling element rolling surface 31 is formed on the moving member 3 at a position facing the rolling element rolling surface 21 formed on the guide shaft 2. The rolling element rolling surface 21 and the loaded rolling element rolling surface 31 form a loaded rolling element rolling path 34. In addition, an unloaded rolling element rolling path 32 is formed in the moving member 3 along the longitudinal direction of the moving member 3.

  The curvatures of the arc shape of the rolling element rolling surface 21 formed on the guide shaft 2 and the arc shape of the loaded rolling element rolling surface 31 formed on the moving member 3 are substantially the same, and the rolling element It is formed larger than the curvature of 4.

  Further, as shown in FIG. 3, an end plate 6 is attached to the end of the moving member 3, and a load rolling element rolling path 34 and a no-load are provided on the surface of the end plate 6 facing the moving member 3. A circulation path 61 that communicates with the rolling element rolling path 32 is formed.

  In this way, the rolling element 4 rolls while receiving a load on the loaded rolling element rolling path 34, and the unloaded rolling element rolling path 32 passes through the circulation path 61 that communicates with one end of the loaded rolling element rolling path 34. An infinite circulation path is formed by rolling and returning to the load rolling element rolling path 34 via the circulation path 61 communicating with the other end of the load rolling element rolling path 34.

  Moreover, as shown in FIG. 1, the some rolling element is hold | maintained in the aligned state by the retainer 5 within the infinite circuit. As shown in FIG. 3, the retainer 5 includes a spacer 51 interposed between the rolling elements 4 and a connecting portion having a rectangular cross section that connects only one side of one end of the spacer 51 with a constant interval. 52. Since the retainer 5 is provided in the ball spline device 1 according to the first embodiment, it is possible to prevent the rolling elements from coming into contact with rolling of the rolling elements 4 and to generate abnormal noise. In addition, it is possible to prevent the rolling element 4 from being damaged and the generation of foreign matter accompanying the contact with the rolling element 4.

  As shown in FIG. 5, the spacer 51 is formed to have an outer diameter smaller than the diameter of the rolling element 4. Further, a protrusion 53 having a rectangular cross section protruding in a direction intersecting with the extending direction of the connecting portion 52 is formed at the end opposite to the connecting end of the connecting portion 52 with the spacer portion 51. In addition, a combined body of the connecting portion 52 and the protruding portion 53 has a substantially T-shaped cross section perpendicular to the traveling direction of the rolling element 4.

  Furthermore, the retainer 5 is formed of resin or the like so that it can be easily bent, and the connecting portion 52 is provided only on one side of the spacer portion 51, so as shown in FIG. The rolling elements 4 can be held flexibly in the circulation path 61.

  As described above, the retainer 5 has a T-shaped cross section perpendicular to the traveling direction of the rolling element 4 in the joined body of the connecting portion 52 and the protruding portion 53. Therefore, the cross-sectional area of the combined body becomes larger than that of the conventional connecting portion provided only on one side of the spacer portion, and the rolling body 4 is repeatedly pulled and relaxed in the traveling direction and further twisted around the traveling direction. It can have sufficient strength against the alternating load.

  In addition, a combined body composed of the protruding portion 53 and the connecting portion 52 is formed in a T-shape that is symmetrical with respect to the extending direction. Therefore, it is possible to make the characteristics in the bending direction uniform without being easily bent in a specific direction or difficult to bend in a specific direction, and to form the retainer 5 having a high degree of freedom capable of bending in any direction. Therefore, the retainer 5 can circulate three-dimensionally with the rolling elements 4.

  Next, the engagement between the retainer holding groove 33 and the retainer 5 will be described.

  As shown in FIG. 2, retainer holding grooves 33 are respectively formed along the loaded rolling element rolling path 34 and the unloaded rolling element rolling path 32. The retainer holding groove 33 is formed in a T shape similarly to the cross-sectional shape of the combined body including the connecting portion 52 and the protruding portion 53 described above. Further, the retainer holding groove 33 formed in the loaded rolling element rolling path 34 is formed in a direction orthogonal to the contact angle line of the rolling element 4.

  The retainer holding groove 33 can be processed at the same time when the load rolling element rolling surface 31 or the no-load rolling element rolling path 32 is formed on the moving member 3 by wire-cut electric discharge machining. Further, the retainer holding groove 33 can be formed by cutting.

  As shown in FIG. 4, the connecting portion 52 and the protruding portion 53 of the retainer 5 are slidably engaged with the retainer holding groove 33 described above. Thus, the retainer 5 aligns the rolling elements 4 and moves while being guided by the retainer holding groove 33.

  Further, as shown in FIG. 3, the circulation path 61 is not provided with a retainer holding groove for guiding the retainer 5. That is, in the circulation path 61, the retainer 5 guides the rolling element 4 by bending between the retainer holding grooves 33 formed along the loaded rolling element rolling path 34 and the unloaded rolling element rolling path 32. Yes. Furthermore, the shape of the circulation path 61 may be set to any shape as long as the movement of the rolling element 4 is not hindered, and the circulation path 61 does not need to be processed with high accuracy.

  Further, as shown in FIG. 3 and FIG. 4, the coupling body 52 and the projection holding portion 53 formed on the retainer 5 and the retainer holding groove 33 are formed inside the path through which the rolling element 4 circulates. Yes. Therefore, the combined body of the connecting portion 52 and the protruding portion 53 can be bent, and the retainer 5 and the rolling element 4 can be smoothly guided in the circulation path 61. Thus, if the retainer holding groove 33 is formed inside the path along which the rolling elements 4 circulate, the members constituting the circulation path 61 are arranged inside the circulation path 61, or the load rolling element rolling path 34 and the non-rotating path In order to smoothly circulate the rolling element 4 at the end of the loaded rolling element rolling path 32, it is not necessary to perform chamfering, and the infinite circulation of the rolling element 4 can be realized easily and inexpensively.

  Moreover, as shown in FIG. 2, the retainer holding groove 33 formed along the loaded rolling element rolling path 34 and the retainer holding groove 33 formed along the unloaded rolling element rolling path 32 are orthogonal to the traveling direction. They are not formed parallel to each other in the cross section. Since the rolling element 4 and the retainer 5 are guided along the retainer holding groove 33 formed in this way, the rolling element 4 and the retainer 5 are not only moved in the longitudinal direction of the moving member 3 but also loaded rolling element rolling. When guided from the runway 34 to the no-load rolling element rollway 32, the guide is twisted in the circumferential direction of the moving member 3 to perform a three-dimensional motion.

  As described above, the rolling element 4 and the retainer 5 circulate along the retainer holding groove 33, and the retainer 5 is formed with the protrusion 53 that acts as a reinforcement. The present invention can be applied not only to a linear guide in which the retainer 5 circulates but also to a ball spline device in which the rolling elements 4 and the retainer 5 circulate three-dimensionally.

  Heretofore, the retainer 5 constituting the ball spline device 1 according to the first embodiment has been described. In the retainer 5 constituting the ball spline device 1 according to the first embodiment, the case where the cross section perpendicular to the traveling direction of the rolling element 4 is formed in a T shape has been described. However, the motion guide apparatus according to the present invention is not limited to the retainer having the T-shaped cross section shown in the first embodiment. Then, next, the retainer which has a shape different from 1st Embodiment is demonstrated. Moreover, about the member which is the same as that of 1st Embodiment, or similar, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

[Second Embodiment]
FIG. 6 is a diagram illustrating a rolling element and a retainer of the motion guide device according to the second embodiment.

  As shown in FIG. 6, the protrusion 54 according to the second embodiment has a circular cross section perpendicular to the traveling direction of the rolling element 4 at the end of the connecting portion 52.

  Although not shown, the retainer holding groove 33 formed in the loaded rolling element rolling path 34 and the unloaded rolling element rolling path 32 is also formed in a circular shape in a cross section perpendicular to the traveling direction of the rolling element 4. The portion 54 is slidably engaged with the retainer holding groove 33.

  As described above, the retainer holding groove 33 formed in the protrusion 54 of the retainer 5, the loaded rolling element rolling path 34 and the unloaded rolling element rolling path 32 has a circular cross section perpendicular to the traveling direction of the rolling element 4. Therefore, similar to the retainer 5 according to the first embodiment described above, the characteristics of the bending direction such as being easy to bend in a specific direction or difficult to bend in a specific direction can be made uniform, and any direction It is possible to form a retainer 5 having a high degree of freedom that can be bent and to prevent the retainer 5 from being twisted when the rolling element 4 and the retainer 5 such as a ball spline device circulate three-dimensionally. It can be done.

  In the above-described embodiment, the unloaded rolling element rolling path 32 has an opening in the direction of the guide shaft 2, and the opening width of the loaded rolling element rolling surface 31 is larger than the outer diameter of the rolling element 4. Even when the guide shaft 2 and the moving member 3 are separated, the rolling element 4 and the retainer 5 are held by the edge of the loaded rolling element rolling surface 31, and the rolling element 4 and the retainer 5 may fall off. Although no ball spline device has been described, the unloaded rolling element rolling path 32 is formed by a hole extending in the longitudinal direction of the moving member 3, and the opening width of the loaded rolling element rolling surface 31 is made larger than the outer shape of the rolling element 4. It doesn't matter. Further, in this case, the retainer holding groove 33 is formed at the bottom of the loaded rolling element rolling surface 31 without separately forming a mechanism for preventing the rolling element 4 and the retainer 5 from falling off on the loaded rolling element rolling surface 31. By engaging with the protrusions 53 and 54 of the retainer 5, a mechanism for preventing the rolling element 4 and the retainer 5 from falling off can be formed.

  Furthermore, in this embodiment, although the case where the cross-sectional shape of the coupling part and the combined part of the projecting part was formed in a substantially T shape or a circular shape was described, the cross-sectional shape of the projecting part is not limited to these. The protrusions may be formed in only one direction from the other end of the connecting part, and the cross-sectional shape of the combined body of the connecting part and the protruding part may be formed in an L shape. Absent. Thus, if the protrusion acts as a retainer reinforcement, the shape of the protrusion is not limited to a symmetrical shape with respect to the connecting portion. Furthermore, in the embodiment described above, the case where the guide shaft is formed linearly has been described, but the guide shaft may be formed in a curved shape. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

1 is an external perspective view of a motion guide device according to a first embodiment. It is sectional drawing for demonstrating the load rolling-element rolling path and unloaded rolling-element rolling path of the exercise | movement guide apparatus which concern on 1st Embodiment. It is a partial cross section figure for demonstrating the internal structure of the exercise | movement guide apparatus which concerns on 1st Embodiment. It is an exploded view for demonstrating the internal structure of the exercise | movement guide apparatus which concerns on 1st Embodiment. It is a figure which shows the rolling element and retainer of the exercise | movement guide apparatus which concern on 1st Embodiment. It is a figure which shows the rolling element and retainer of the exercise | movement guide apparatus which concern on 2nd Embodiment.

Explanation of symbols

  1 Ball spline device, 2 Guide shaft, 3 Moving member, 4 Rolling element, 5 Retainer, 6 End plate, 21 Rolling element rolling surface, 31 Loaded rolling element rolling surface, 32 Unloaded rolling element rolling path, 33 Retainer holding Groove, 34 load rolling element rolling path, 51 spacer, 52 connecting part, 53, 54 protrusion, 61 circulation path.

Claims (4)

A guide shaft on which rolling element rolling surfaces are formed along the longitudinal direction;
A loaded rolling element rolling surface and an unloaded rolling element rolling path formed to face the rolling element rolling surface so as to form a loaded rolling element rolling path together with the rolling element rolling surface are formed to form the guide shaft. And a movable member combined in a freely movable relative manner,
A motion guide device comprising a plurality of rolling elements arranged in an infinite circulation path including the loaded rolling element rolling path and the unloaded rolling element rolling path and circulated along with relative movement of the guide shaft and the moving member. And
A plurality of spacers interposed between the rolling elements, and a retainer provided with a connecting part for connecting one end of the spacers only on one side of the spacers,
The connection part has a projection part protruding in a direction intersecting with the extension direction of the connection part at the end opposite to the connection end with the spacer part. The motion guide device according to claim 1,
The movement guide device, wherein the protrusion protrudes symmetrically with respect to the connecting portion. The motion guide apparatus according to claim 1 or 2,
The motion guide apparatus, wherein the protrusion is engaged with a retainer holding groove formed along at least the load rolling element rolling surface. A plurality of spacers interposed between the rolling elements,
Provided only on one side of the spacer portion with a connecting portion that connects one end of the spacer portions,
The said connection part has a projection part which protrudes in the direction which cross | intersects with respect to the extension direction of the said connection part in the edge part on the opposite side to the connection end with the said spacer part, The retainer characterized by the above-mentioned.

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