Linear motion guide device

Abstract

A linear motion guide device includes a guide rail, a sliding member guided by the guide rail in a first axial direction, and a rolling body that can roll in a circulation passage including a rolling passage defined between the guide rail and the sliding member, a return passage provided inside the sliding member, and a direction conversion passage connecting the rolling passage and the return passage. The return passage has a through hole extending in the first axial direction inside the sliding member and a return guide member disposed in the through hole. The return guide member includes a circular-arc-shaped outer surface opposite a portion of an inner peripheral surface of the through hole in a prescribed surface orthogonal to a central axis of the through hole, an inner surface of which at least a portion is in contact with the rolling body, a first end surface connecting one end portion of the central axis of the outer surface in a peripheral direction and the inner surface, and a second end surface connecting another end portion of the central axis of the outer surface in the peripheral direction and the inner surface, and separated from the first end surface.

Description

Technical Field

[0001] This disclosure relates to a linear motion guide device provided in a guide section of a machine tool, manufacturing apparatus, measuring device, etc., and used to linearly move a moving component such as a worktable. Background Technology

[0002] The linear motion guiding device consists of a guide rail, a slider, and multiple balls. The guide rail extends axially and has ball rolling grooves formed on both sides. The slider is configured across the guide rail and includes: a ball rolling groove located opposite to the ball rolling groove of the guide rail; two ends of a ball return path formed parallel to the ball rolling path; and a ball direction conversion path connecting the two ends of the ball rolling path and the ball return path. The multiple balls are arranged in a ball circulation path formed by the ball rolling groove of the guide rail, the ball rolling groove of the slider, the ball return path, and the direction conversion path.

[0003] The slider consists of a slider body and end caps. The slider body has a ball rolling groove and a ball return path, and the end caps have a direction conversion path and are fixed to both axial end faces of the slider body. In the field of linear motion guiding devices, linear motion guiding devices with a slider body having a return path for rolling elements, as disclosed in Patent Document 1, are known. In Patent Document 1, the return path has a through hole provided inside the slider body and a return guide member disposed in the through hole. Even if the inner diameter of the through hole is large, small-diameter rolling elements can roll in the return path by disposing the return guide member in the through hole. Since it is not necessary to reduce the inner diameter of the through hole, the reduction in machinability when forming the through hole is suppressed.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2008-175263 Summary of the Invention

[0007] The problem the invention aims to solve

[0008] Although it is not necessary to reduce the inner diameter of the through-hole by configuring the return guide member in the through-hole, a small inner diameter of the through-hole is preferred when miniaturization of the linear motion guide device is required. A technology is desired that allows the return guide member to be smoothly configured in the through-hole even with a reduced inner diameter.

[0009] The purpose of this disclosure is to provide a linear motion guide device that suppresses the reduction of workability and the increase of size when a return guide member is configured in a through hole.

[0010] Solution for solving the problem

[0011] A linear motion guiding device according to the present disclosure comprises: a guide rail; a slider guided by the guide rail along a first axis direction; and a rolling element capable of rolling in a circulation path, the circulation path including a rolling path defined between the guide rail and the slider, a return path disposed inside the slider, and a direction conversion path connecting the rolling path and the return path, the return path having a through hole extending inside the slider along the first axis direction and a return guiding member disposed in the through hole, the return guiding member comprising: an arc-shaped outer surface opposite a portion of the inner circumferential surface of the through hole in a defined plane orthogonal to the central axis of the through hole; an inner surface at least a portion of which contacts the rolling element; a first end face connecting one circumferential end of the central axis of the outer surface to the inner surface; and a second end face connecting the other circumferential end of the central axis of the outer surface to the inner surface and separated from the first end face.

[0012] Based on the above, by forming the return guide member with a first end face and a second end face separate from the first end face, the return guide member can be elastically deformed by reducing the outer diameter of the return member. Therefore, even if the inner diameter of the through hole is small, the return guide member can be elastically deformed while being inserted into the through hole. As a result, the decrease in workability when the return guide member is placed in the through hole is suppressed. Furthermore, since the inner diameter of the through hole can be made small, for example, even when multiple return paths are arranged adjacent to each other in a specified surface, the enlargement of the linear motion guide device can be suppressed.

[0013] As a desired technical solution for the linear motion guiding device disclosed herein, the inner surface may include an arcuate region, a first straight region, and a second straight region in the specified surface. The first straight region is connected to one end of the central axis of the arcuate region in the circumferential direction and extends along the tangential direction of the rolling element. The second straight region is connected to the other end of the central axis of the arcuate region in the circumferential direction and extends along the tangential direction of the rolling element.

[0014] Based on the above, when the return guide member is positioned in the through hole, even if the return guide member elastically deforms with its first and second end faces approaching each other, excessive contact between the rolling element and the inner surface of the return guide member can be suppressed. Therefore, the rolling element can roll smoothly inside the return guide member. Furthermore, by providing the first and second straight-line regions, the return guide member can be smoothly extracted from the mold when it is formed using a mold.

[0015] As a desired technical solution for the linear motion guiding device of this disclosure, it is also possible that the curvature of the arc region in the specified surface is smaller than the curvature of the rolling element.

[0016] Based on the above, excessive contact between the rolling element and the inner surface of the return guide member is suppressed. Therefore, the rolling element can roll smoothly inside the return guide member.

[0017] As a desired technical solution for the linear motion guiding device of this disclosure, the contact point between the rolling element and the inner surface may also be defined as at least one of the intersection of the arcuate region and the first linear region, and the intersection of the arcuate region and the second linear region.

[0018] Based on the above, the rolling element can be supported by a portion of the inner surface of the return guide member while rolling smoothly inside the return guide member.

[0019] As a desired technical solution for the linear motion guiding device of this disclosure, it is also possible that the first linear region and the second linear region are parallel in the specified surface.

[0020] Based on the above, when the return guide member is positioned in the through hole, even if the return guide member elastically deforms with its first and second end faces approaching each other, excessive contact between the rolling element and the inner surface of the return guide member can be suppressed. Therefore, the rolling element can roll smoothly inside the return guide member. Furthermore, by setting the first and second straight regions to be parallel, the return guide member can be smoothly pulled out of the mold when it is formed using a mold.

[0021] As a desired technical solution for the linear motion guiding device of this disclosure, the rolling element may also contact the inner circumferential surface between the first end face and the second end face.

[0022] Based on the above, the rolling element can be supported by the inner surface of the return guide member and the inner circumferential surface of the through hole, respectively, while rolling smoothly in the return path.

[0023] As a desired technical solution for the linear motion guiding device of this disclosure, the outer surface may be opposite to a support region that is defined as at least half of the inner circumferential surface in the circumferential direction of the central axis.

[0024] Based on the above, the outer surface of the return guide member is supported by more than half of the support area of ​​the inner circumferential surface of the through hole. Therefore, after the return guide member is positioned in the through hole, movement of the return guide member inside the through hole is suppressed. Thus, the rolling element can roll smoothly inside the return guide member.

[0025] As a desired technical solution for the linear motion guiding device of this disclosure, the return path may be positioned on the second axis direction orthogonal to the first axis direction on the specified surface, relative to the center of the slider, at a position outside the rolling path, and the opening between the first end face and the second end face may be positioned on the second axis direction at a position outside the central axis.

[0026] Based on the above, the situation where the turning radius of the rolling element decreases when rolling in the direction-changing path between the return path and the rolling path is suppressed. Therefore, the rolling element can roll smoothly in the direction-changing path.

[0027] As a desired technical solution for the linear motion guiding device of this disclosure, the return guiding member may also include a first return guiding member and a second return guiding member connected to the end of the first return guiding member in the first axial direction.

[0028] Based on the above, even if the through hole is long in the first axial direction, the return guide member can be smoothly positioned in the through hole by inserting the first return guide member from one end of the through hole and the second return guide member from the other end of the through hole.

[0029] As a desired technical solution for the linear motion guiding device of this disclosure, the slider may also include: a slider body having the through hole; an end cap connected to the end of the slider body in the first axial direction; and a return guide disposed between the slider body and the end cap in a manner opposite to the end cap, the direction conversion passage being defined between the end cap and the return guide, the return guide being integral with at least one of the return guide and the end cap.

[0030] Based on the above, since the return guide component is integrated with at least one of the return guide and the end cap, the number of components in the linear motion guide device can be reduced.

[0031] The effects of the invention

[0032] According to this disclosure, a linear motion guide device is provided that suppresses the reduction of workability and the increase of size when the return guide member is configured in the through hole. Attached Figure Description

[0033] Figure 1 This is a perspective view showing the linear motion guide device of the first embodiment.

[0034] Figure 2This is a front view showing a section of the linear motion guide device of the first embodiment.

[0035] Figure 3 This is a cross-sectional view showing a portion of the linear motion guide device according to the first embodiment.

[0036] Figure 4 This is a perspective view schematically showing the return path of the first embodiment.

[0037] Figure 5 This is a cross-sectional view showing the return path of the first embodiment.

[0038] Figure 6 This is a cross-sectional view showing the return path of the second embodiment.

[0039] Figure 7 This is a cross-sectional view showing the return path of the third embodiment.

[0040] Figure 8 This is a perspective view schematically showing the return path of the fourth embodiment.

[0041] Figure 9 This is a top view schematically showing the return path of the fifth embodiment.

[0042] Figure 10 This is a top view schematically showing the return path of the sixth embodiment. Detailed Implementation

[0043] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings, but the present disclosure is not limited thereto. The constituent elements of the embodiments described below can be appropriately combined. In addition, there are cases where some constituent elements are not used.

[0044] In this implementation, an XYZ orthogonal coordinate system is established, and the positional relationships of each part are explained with reference to this system. The direction parallel to the X-axis (first axis) in the horizontal plane is defined as the X-axis direction (first axis direction). The direction orthogonal to the X-axis and parallel to the Y-axis (second axis) in the horizontal plane is defined as the Y-axis direction (second axis direction). The direction orthogonal to the horizontal plane and parallel to the Z-axis (third axis) is defined as the Z-axis direction (third axis direction). The YZ plane is a defined plane containing the Y-axis and Z-axis, and is orthogonal to the X-axis.

[0045] [First Implementation]

[0046] The first embodiment will be described. Figure 1 This is a perspective view showing the linear motion guide device 1 of this embodiment. Figure 2 This is a front view showing a section of the linear motion guide device 1 of this embodiment. Figure 3This is a cross-sectional view showing a portion of the linear motion guide device 1 of this embodiment.

[0047] like Figure 1 and Figure 2 As shown, the linear motion guiding device 1 includes: a guide rail 2; a slider 3 guided by the guide rail 2 along the X-axis direction; and a rolling element 4 capable of rolling in a circulation path 100, the circulation path 100 including a rolling path 5 defined between the guide rail 2 and the slider 3, a return path 6 disposed inside the slider 3, and a direction conversion path 7 connecting the rolling path 5 and the return path 6.

[0048] Guide rail 2 guides slider 3 along the X-axis. Guide rail 2 extends along the X-axis. Guide rail 2 has a rolling groove 8 extending along the X-axis. At least a portion of rolling element 4 is disposed inside the rolling groove 8. The inner surface of the rolling groove 8 includes a rolling surface 9 supporting the rolling element 4. The rolling element 4 rolls while in contact with the rolling surface 9.

[0049] Three rolling grooves 8 are provided on each of the +Y and -Y sides of the guide rail 2. On the +Y side of the guide rail 2, three rolling grooves 8 are arranged in the Z-axis direction. On the -Y side of the guide rail 2, three rolling grooves 8 are arranged in the Z-axis direction.

[0050] The slider 3 is guided by the guide rail 2 while moving relative to the guide rail 2 along the X-axis. At least a portion of the slider 3 is opposite to the guide rail 2 via the rolling element 4.

[0051] The slider 3 includes: a slider body 31 extending along the X-axis; an end cap 33 connected to the end of the slider body 31 in the X-axis direction; and a return guide 32 disposed between the slider body 31 and the end cap 33 opposite to the end cap 33. The slider body 31 is made of metal. The return guide 32 and the end cap 33 are both made of synthetic resin. Alternatively, one or both of the return guide 32 and the end cap 33 may be made of metal. For example, one or both of the return guide 32 and the end cap 33 may be made of iron, steel, stainless steel, or aluminum.

[0052] The slider body 31 is configured across the guide rail 2. The slider body 31 includes: legs 31F, which are respectively configured on the +Y side and -Y side of the guide rail 2; and a body part 31B, which is configured at a position closer to the +Z side than the guide rail 2, connecting the pair of legs 31F.

[0053] The slider body 31 has a rolling groove 10 extending along the X-axis. The rolling groove 10 of the slider body 31 is opposite to the rolling groove 8 of the guide rail 2. The rolling groove 10 is formed on the inner surface of the leg 31F opposite to the guide rail 2. At least a portion of the rolling element 4 is disposed inside the rolling groove 10. The inner surface of the rolling groove 10 includes a rolling surface 11 that supports the rolling element 4. The rolling element 4 rolls while in contact with the rolling surface 11.

[0054] Three rolling grooves 10 are provided on the inner surface of the leg 31F located at a position closer to the +Y side than the guide rail 2, and three are provided on the inner surface of the leg 31F located at a position closer to the -Y side than the guide rail 2. Three rolling grooves 10 are provided on the inner surface of the leg 31F located at a position closer to the +Y side than the guide rail 2 in the Z-axis direction. Three rolling grooves 10 are provided on the inner surface of the leg 31F located at a position closer to the -Y side than the guide rail 2 in the Z-axis direction.

[0055] The rolling element 4 is a metal ball. Multiple rolling elements 4 are provided. The rolling element 4 can roll and pass through the circulation path 100, which includes the rolling path 5, the return path 6, and the direction change path 7.

[0056] Rolling passage 5 is defined between rolling surface 9 and rolling surface 11. Rolling passage 5 extends along the X-axis between guide rail 2 and slider 3. Rolling element 4 can move along the X-axis while rolling in rolling passage 5. Rolling element 4 rolls in rolling passage 5 under load. Three rolling passages 5 are provided between guide rail 2 and leg 31F located on the +Y side of guide rail 2. Three rolling passages 5 are provided between guide rail 2 and leg 31F located on the -Y side of guide rail 2. Rolling element 4 rolls in rolling passage 5 while contacting rolling surface 9 and rolling surface 11 respectively.

[0057] The return path 6 is disposed inside the slider body 31. The return path 6 extends along the X-axis inside the slider body 31. The rolling element 4 can move along the X-axis while rolling in the return path 6. The rolling element 4 rolls in the return path 6 without load. The return path 6 is disposed in the Y-axis direction at a position outside the rolling path 5 relative to the center of the slider 3. In this embodiment, the return path 6 is disposed inside the leg 31F. One return path 6 is provided relative to one rolling path 5. In this embodiment, six rolling paths 5 are provided. Six return paths 6 are also provided. The rolling paths 5 and the return path 6 are substantially parallel.

[0058] The direction of travel of the rolling element 4 moving in the rolling path 5 is opposite to the direction of travel of the rolling element 4 moving in the return path 6. When the rolling element 4 in the rolling path 5 moves in the +X direction in the rolling path 5, the rolling element 4 in the return path 6 moves in the -X direction in the return path 6. When the rolling element 4 in the rolling path 5 moves in the -X direction in the rolling path 5, the rolling element 4 in the return path 6 moves in the +X direction in the return path 6.

[0059] The direction-changing passage 7 allows the rolling element 4, which rolls from one of the rolling passages 5 to the other, to pass through. The direction-changing passage 7 is defined between the end cap 33 and the return guide 32.

[0060] End caps 33 are connected to the +X side end and the -X side end of the slider body 31, respectively. End caps 33 are fixed to the slider body 31, for example, by bolts 33B. Return guides 32 are connected to the +X side end and the -X side end of the slider body 31, respectively, opposite to the end caps 33.

[0061] The direction conversion path 7 is configured to connect the +X side end of the rolling path 5 and the +X side end of the return path 6. The direction conversion path 7 is configured to connect the -X side end of the rolling path 5 and the -X side end of the return path 6. The direction conversion path 7 is an arc shape connecting the ends of the rolling path 5 and the return path 6.

[0062] For example, a rolling element 4 that moves in the +X direction in rolling path 5 and enters the direction-changing path 7 from the +X side end of rolling path 5 can, after moving in the direction-changing path 7, enter the return path 6 from the +X side end of return path 6. The rolling element 4 that enters the return path 6 from the +X side end of return path 6 moves in the -X direction in return path 6. A rolling element 4 that moves in the +X direction in return path 6 and enters the direction-changing path 7 from the +X side end of return path 6 can, after moving in the direction-changing path 7, enter the rolling path 5 from the +X side end of rolling path 5. The rolling element 4 that enters the rolling path 5 from the +X side end of rolling path 5 moves in the -X direction in rolling path 5.

[0063] The rolling path 5, the return path 6, and the direction conversion path 7 form a circulation path 100 for the rolling element 4. By having the rolling element 4 roll in a cyclic manner within the circulation path 100, the sliding element 3 can move relative to the guide rail 2 in the +X and -X directions, respectively.

[0064] Next, the return path 6 of this embodiment will be described. Figure 4 This is a perspective view schematically showing the return path 6 of this embodiment. Figure 5This is a cross-sectional view showing the return path 6 in this embodiment.

[0065] like Figure 2 , Figure 3 , Figure 4 as well as Figure 5 As shown, in this embodiment, the return passage 6 has a through hole 12 extending along the X-axis direction inside the slider 3 and a return guide member 13 disposed in the through hole 12.

[0066] A through hole 12 is provided inside the slider body 31. The through hole 12 extends along the X-axis inside the slider body 31. The central axis AX of the through hole 12 is parallel to the X-axis. The central axis AX passes through the center of the through hole 12 in the YZ plane. In the YZ plane orthogonal to the central axis AX, the through hole 12 is circular. The through hole 12 has an inner circumferential surface disposed around the central axis AX.

[0067] As described above, the slider body 31 is made of metal. The through hole 12 is formed in the slider body 31 using a tool such as a drill bit.

[0068] The return guide member 13 is disposed in the through hole 12. The return guide member 13 is made of synthetic resin. Alternatively, the return guide member 13 may also be made of rubber. The operator can elastically deform the return guide member 13 by applying force by hand.

[0069] like Figure 5 As shown, the return guide member 13 includes: an arc-shaped outer surface 14, which faces a portion of the inner circumferential surface of the through hole 12 in the YZ plane orthogonal to the central axis AX; an inner surface 15, at least a portion of which contacts the rolling element 4; a first end face 16, which connects one end of the outer surface 14 in the circumferential direction of the central axis AX to the inner surface 15; and a second end face 17, which connects the other end of the outer surface 14 in the circumferential direction of the central axis AX to the inner surface 15 and is separated from the first end face 16. That is, in this embodiment, the return guide member 13 is C-shaped in the YZ plane. An opening 18 is provided between the first end face 16 and the second end face 17.

[0070] The size and shape of the cross section of the return guide member 13, which is parallel to the YZ plane, are uniform in the X-axis direction.

[0071] The outer surface 14 of the return guide member 13 contacts a portion of the inner circumferential surface of the through hole 12 in the YZ plane. In the following description, the region in the inner circumferential surface of the through hole 12 opposite to the outer surface 14 of the return guide member 13 is appropriately referred to as the support region 12A. Furthermore, in the following description, the region in the inner circumferential surface of the through hole 12 between the first end face 16 and the second end face 17 is appropriately referred to as the exposed region 12B.

[0072] The support region 12A is defined as at least half of the inner circumferential surface of the through hole 12 in the circumferential direction along the central axis AX. The support region 12A occupies more than 51% and less than 99% of the inner circumferential surface of the through hole 12 in the circumferential direction along the central axis AX. Figure 5 In the example shown, the support region 12A occupies approximately 70% of the inner circumferential surface of the through hole 12 in the circumferential direction of the central axis AX.

[0073] The exposed area 12B is a region in the inner circumferential surface of the through hole 12 that differs from the area occupied by the support area 12A. The exposed area 12B is located inside the opening 18. The rolling element 4 contacts at least a portion of the exposed area 12B between the first end face 16 and the second end face 17.

[0074] The outer surface 14 of the return guide member 13 contacts the support area 12A. The return guide member 13 does not contact the exposed area 12B.

[0075] The opening 18 between the first end face 16 and the second end face 17 is positioned outward of the center of the slider 3 in the Y-axis direction relative to the center axis AX. That is, the return guide member 13 is positioned in the through hole 12 with the opening 18 facing outward of the center axis AX. The support region 12A is defined in the Y-axis direction at a position closer to the center of the slider 3 than the opening 18 and the exposed region 12B.

[0076] The inner surface 15 of the return guide member 13 includes an arc region 15A, a first straight region 15B, and a second straight region 15C in the YZ plane. The first straight region 15B is connected to one end of the central axis AX of the arc region 15A in the circumferential direction, and the second straight region 15C is connected to the other end of the central axis AX of the arc region 15A in the circumferential direction.

[0077] The first straight region 15B extends in the YZ plane along the tangent direction of the outer surface of the rolling element 4. The second straight region 15C extends in the YZ plane along the tangent direction of the outer surface of the rolling element 4.

[0078] In the YZ plane, the first straight line region 15B and the second straight line region 15C are substantially parallel.

[0079] In the YZ plane, the curvature of the arc region 15A is smaller than the curvature of the outer surface of the rolling element 4. In the YZ plane, the curvature of the inner circumferential surface of the through hole 12 is smaller than the curvature of the arc region 15A.

[0080] The rolling element 4 contacts the inner surface 15 at a contact point P, which is defined as a portion of the inner surface 15 of the return guide member 13. The rolling element 4 also contacts the inner circumferential surface of the through hole 12 at a contact point P, which is defined as a portion of the inner circumferential surface of the through hole 12. In this embodiment, the contact points P between the rolling element 4 and the inner surface 15 of the return guide member 13 are respectively defined at the intersection of the arcuate region 15A and the first straight region 15B, and at the intersection of the arcuate region 15A and the second straight region 15C. That is, the rolling element 4 rolls while contacting the intersection of the arcuate region 15A and the first straight region 15B, and at the intersection of the arcuate region 15A and the second straight region 15C, respectively. In this embodiment, the rolling element 4 does not contact the arcuate region 15A.

[0081] The contact point P between the rolling element 4 and the inner circumferential surface of the through hole 12 is defined in the exposed area 12B.

[0082] Alternatively, the rolling element 4 may separate from the boundary between the arc region 15A and the second straight region 15C upon contact with the boundary between the arc region 15A and the first straight region 15B. Alternatively, the rolling element 4 may separate from the boundary between the arc region 15A and the first straight region 15B upon contact with the boundary between the arc region 15A and the second straight region 15C. Alternatively, the rolling element 4 may contact a portion of the arc region 15A.

[0083] Alternatively, gaps may be provided between the rolling element 4 and the inner surface 15 of the return guide member 13, and between the rolling element 4 and the inner circumferential surface of the through hole 12. That is, in Figure 5 In the example shown, there are three contact points P around the rolling element 4, but there could also be only one contact point P. Alternatively, a small gap could be provided between the rolling element 4 and the return path 6, so that the rolling element 4 rolls in the return path 6 without contacting either the boundary between the arc region 15A and the first straight region 15B, or the boundary between the arc region 15A and the second straight region 15C.

[0084] The distance between the contact point P at the intersection of the arc region 15A and the first straight region 15B, and the contact point P at the intersection of the arc region 15A and the second straight region 15C, is the same as or slightly larger than the diameter of the rolling element 4. The rolling element 4 is able to roll inside the return guide member 13 in an unloaded state.

[0085] Next, the assembly method of the slider 3 according to this embodiment will be described. A through hole 12 is formed in the slider body 31 using a tool such as a drill bit. The return guide member 13 is manufactured, for example, by injection molding. The operator inserts the return guide member 13 into the through hole 12. The return guide member 13 has a first end face 16 and a second end face 17. The operator applies force to the return guide member 13 by hand, thereby enabling the return guide member 13 to elastically deform in such a way that the first end face 16 and the second end face 17 are brought closer together and the outer diameter of the return guide member 13 decreases. The operator can smoothly insert the return guide member 13 into the through hole 12 in a state of elastic deformation.

[0086] After inserting the return guide member 13 into the through hole 12, the operator connects the return guide member 32 and the end cap 33 at the end of the slider body 31 in the X-axis direction. Thus, a direction conversion passage 7 is formed in the slider 3.

[0087] As explained above, according to this embodiment, by forming the return guide member 13 with a first end face 16 and a second end face 17 separated from the first end face 16, the return guide member 13 can be elastically deformed in such a way that its outer diameter decreases. Therefore, even if the inner diameter of the through hole 12 is small, the operator can insert the return guide member 13 into the through hole 12 while elastically deforming it. As a result, the decrease in workability when the return guide member 13 is placed in the through hole 12 is suppressed. Furthermore, since the inner diameter of the through hole 12 can be made smaller, even when multiple return passages 6 are arranged adjacent to each other in the YZ plane, the enlargement of the linear motion guide device 1 can be suppressed.

[0088] The inner surface 15 of the return guide member 13 includes an arcuate region 15A, a first straight region 15B, and a second straight region 15C in the YZ plane. The first straight region 15B is connected to one end of the central axis AX of the arcuate region 15A in the circumferential direction and extends along the tangential direction of the rolling element 4. The second straight region 15C is connected to the other end of the central axis AX of the arcuate region 15A in the circumferential direction and extends along the tangential direction of the rolling element 4. Therefore, when the return guide member 13 is positioned in the through hole 12, even if the return guide member 13 elastically deforms with the first end face 16 and the second end face 17 approaching each other, contact between the first straight region 15B and the rolling element 4, and contact between the second straight region 15C and the rolling element 4, are suppressed. Thus, excessive contact between the rolling element 4 and the inner surface 15 of the return guide member 13 is prevented. Consequently, the rolling element 4 can roll smoothly inside the return guide member 13. Furthermore, when the return guide member 13 is formed by injection molding, by providing the first straight region 15B and the second straight region 15C, the return guide member 13 can be smoothly pulled out of the mold.

[0089] In the YZ plane, the curvature of the arc region 15A is smaller than that of the rolling element 4. This prevents excessive contact between the rolling element 4 and the inner surface 15 of the return guide member 13. Consequently, the rolling element 4 can roll smoothly inside the return guide member 13.

[0090] The contact point P between the rolling element 4 and the inner surface 15 of the return guide member 13 is defined at least one of the intersection of the arc region 15A and the first straight region 15B, and the intersection of the arc region 15A and the second straight region 15C. Thus, the rolling element 4 can smoothly roll inside the return guide member 13 while being supported by a portion of the inner surface 15 of the return guide member 13.

[0091] In the YZ plane, the first straight region 15B and the second straight region 15C are parallel. Therefore, when the return guide member 13 is positioned in the through hole 12, even if the return guide member 13 elastically deforms with its first end face 16 and second end face 17 approaching each other, contact between the first straight region 15B and the rolling element 4, and contact between the second straight region 15C and the rolling element 4, are suppressed. Thus, excessive contact between the rolling element 4 and the inner surface 15 of the return guide member 13 is prevented. Consequently, the rolling element 4 can roll smoothly inside the return guide member 13. Furthermore, when the return guide member 13 is formed by injection molding, by setting the first straight region 15B and the second straight region 15C to be parallel, the return guide member 13 can be smoothly pulled out of the mold.

[0092] The rolling element 4 contacts the exposed area 12B of the through hole 12 between the first end face 16 and the second end face 17. Thus, the rolling element 4 can roll smoothly in the return passage 6 while being supported by the inner surface 15 of the return guide member 13 and the inner peripheral surface of the through hole 12.

[0093] The outer surface 14 of the return guide member 13 is opposite to a support region 12A, which is defined as at least half of the inner circumferential surface of the through hole 12 in the circumferential direction along the central axis AX. Thus, the outer surface 14 of the return guide member 13 is supported by the support region 12A, which is more than half of the inner circumferential surface of the through hole 12. Therefore, after the return guide member 13 is positioned in the through hole 12, movement of the return guide member 13 inside the through hole 12 is suppressed. Consequently, the rolling element 4 can roll smoothly inside the return guide member 13.

[0094] The return path 6 is positioned outward of the center of the slider 3 in the Y-axis direction, relative to the outer edge of the rolling path 5. The opening 18 between the first end face 16 and the second end face 17 is positioned outward of the central axis AX in the Y-axis direction. Therefore, the tendency for the turning radius of the rolling element 4 to decrease when rolling in the direction-changing path 7 between the return path 6 and the rolling path 5 is suppressed. Consequently, the rolling element 4 can roll smoothly in the direction-changing path 7.

[0095] [Second Implementation]

[0096] The second embodiment will be described. In the following description, the same reference numerals are used to refer to the same or equivalent components as those in the embodiment described above, and their descriptions are simplified or omitted.

[0097] Figure 6 This is a cross-sectional view showing the return path 6 in this embodiment. For example... Figure 6 As shown, it is also possible that, in the YZ plane, the first straight line region 15B and the second straight line region 15C are inclined outward from the center of the slider 3 in the Y-axis direction in such a way that the distance between the first straight line region 15B and the second straight line region 15C becomes shorter.

[0098] The contact point P between the rolling element 4 and the inner surface 15 of the return guide member 13 is defined at the junction of the arc region 15A and the first straight region 15B, and at the junction of the arc region 15A and the second straight region 15C, respectively.

[0099] In this embodiment, the decrease in workability when the return guide member 13 is arranged in the through hole 12 is also suppressed, and the enlargement of the linear motion guide device 1 is also suppressed.

[0100] [Third Implementation]

[0101] Figure 7 This is a cross-sectional view showing the return path 6 in this embodiment. For example... Figure 7 As shown, it is also possible that, in the YZ plane, the first straight line region 15B and the second straight line region 15C are inclined outward from the center of the slider 3 in the Y-axis direction in such a way that the distance between the first straight line region 15B and the second straight line region 15C increases.

[0102] The contact point P between the rolling element 4 and the inner surface 15 of the return guide member 13 is defined at the junction of the arc region 15A and the first straight region 15B, and at the junction of the arc region 15A and the second straight region 15C, respectively.

[0103] In this embodiment, the decrease in workability when the return guide member 13 is arranged in the through hole 12 is also suppressed, and the enlargement of the linear motion guide device 1 is also suppressed.

[0104] [Fourth Implementation]

[0105] Figure 8 This is a perspective view schematically illustrating the return path 6 of this embodiment. (As shown) Figure 8 As shown, the return guide member 13 may also include a first return guide member 131 and a second return guide member 132 connected to the end of the first return guide member 131 in the X-axis direction. That is, the return guide member 13 may also be formed by combining multiple members.

[0106] According to this embodiment, even if the through hole 12 is long in the X-axis direction, the return guide member 13 can be smoothly arranged in the through hole 12 by inserting the first return guide member 131 from one end of the through hole 12 and the second return guide member 132 from the other end of the through hole 12.

[0107] [Fifth Implementation]

[0108] Figure 9 This is a top view schematically illustrating the return path 6 of this embodiment. (Example) Figure 9 As shown, the return guide member 13 and the return guide element 32 can also be integrated. When both the return guide member 13 and the return guide element 32 are made of synthetic resin, they can be injection molded using a single mold to integrally form the return guide member 13 and the return guide element 32. According to this embodiment, the number of components in the linear motion guide device 1 can be reduced.

[0109] [Sixth Implementation]

[0110] Figure 10 This is a top view schematically illustrating the return path 6 of this embodiment. (Example) Figure 10 As shown, the return guide member 13 and the end cap 33 can also be integrated. When both the return guide member 13 and the end cap 33 are made of synthetic resin, they can also be injection molded using a single mold to integrally form the return guide member 13 and the end cap 33. In this embodiment, the number of components in the linear motion guide device 1 can also be reduced.

[0111] [Other Implementation Methods]

[0112] In the above embodiment, the return guide member 13 is disposed in the through hole 12 with the opening 18 between the first end face 16 and the second end face 17 facing outward relative to the center of the slider 3. Alternatively, the return guide member 13 may be disposed in the through hole 12 with the opening 18 facing the center of the slider 3. Alternatively, the return guide member 13 may be disposed in the through hole 12 with the opening 18 facing the +Z direction. Alternatively, the return guide member 13 may be disposed in the through hole 12 with the opening 18 facing the -Z direction.

[0113] In the above embodiment, with the return guide member 13 disposed in the through hole 12, an opening 18 is formed between the first end face 16 and the second end face 17. Alternatively, with the return guide member 13 disposed in the through hole 12, the first end face 16 and the second end face 17 may be in contact. That is, the support region 12A may occupy approximately 100% of the inner circumferential surface of the through hole 12 in the circumferential direction of the central axis AX.

[0114] Explanation of reference numerals in the attached figures

[0115] 1. Linear motion guide device; 2. Guide rail; 3. Slider; 4. Rolling element; 5. Rolling path; 6. Return path; 7. Direction conversion path; 8. Rolling groove; 9. Rolling surface; 10. Rolling groove; 11. Rolling surface; 12. Through hole; 12A. Support area; 12B. Exposed area; 13. Return guide member; 14. Outer surface; 15. Inner surface; 15A. Arc area; 15B. First straight area; 15C. Second straight area; 16. First end face; 17. Second end face; 18. Opening; 31. Slider body; 31B. Main body; 31F. Leg; 32. Return guide member; 33. End cap; 33B. Bolt; 100. Circulation path; 131. First return guide member; 132. Second return guide member; AX. Central axis; P. Contact point.

Claims

1. A linear motion guiding device, wherein, The linear motion guiding device has the following features: guide; The sliding member, guided by the guide rail along the first axis direction; and A rolling element capable of rolling in a circulation path, the circulation path including a rolling path defined between the guide rail and the slider, a return path disposed inside the slider, and a direction-changing path connecting the rolling path and the return path. The return path has a through hole extending along the first axis direction inside the slider and a return guide member disposed in the through hole. The return guide member includes: an arc-shaped outer surface that faces a portion of the inner circumferential surface of the through hole in a predetermined plane orthogonal to the central axis of the through hole; an inner surface, at least a portion of which contacts the rolling element; a first end face that connects one circumferential end of the central axis of the outer surface to the inner surface; and a second end face that connects the other circumferential end of the central axis of the outer surface to the inner surface and is separate from the first end face. The inner surface includes an arc region, a first straight region, and a second straight region in the specified surface. The first straight region is connected to one end of the central axis of the arc region in the circumferential direction and extends along the tangential direction of the rolling element. The second straight region is connected to the other end of the central axis of the arc region in the circumferential direction and extends along the tangential direction of the rolling element.

2. The linear motion guiding device according to claim 1, wherein, In the specified surface, the curvature of the arc region is smaller than the curvature of the rolling element.

3. The linear motion guiding device according to claim 2, wherein, The contact point between the rolling element and the inner surface is defined as at least one of the intersection of the arc region and the first straight region, and the intersection of the arc region and the second straight region.

4. The linear motion guiding device according to claim 2, wherein, In the specified surface, the first straight line region and the second straight line region are parallel.

5. The linear motion guiding device according to any one of claims 1 to 4, wherein, The rolling element contacts the inner circumferential surface between the first end face and the second end face.

6. The linear motion guiding device according to any one of claims 1 to 4, wherein, The outer surface is opposite to a support region defined as at least half of the inner circumferential surface in the circumferential direction along the central axis.

7. The linear motion guiding device according to any one of claims 1 to 4, wherein, The return path is positioned outside the rolling path relative to the center of the slider on the second axis direction, which is orthogonal to the first axis direction, on the specified surface. The opening between the first end face and the second end face is positioned on the outer side of the central axis in the second axial direction.

8. The linear motion guiding device according to any one of claims 1 to 4, wherein, The return guide member includes a first return guide member and a second return guide member connected to an end of the first return guide member in the first axial direction.

9. The linear motion guiding device according to any one of claims 1 to 4, wherein, The slider includes: a slider body having the through hole; an end cap connected to an end of the slider body in the first axial direction; and a return guide disposed between the slider body and the end cap in a manner opposite to the end cap. The direction conversion path is defined between the end cap and the return guide. The return guide component is integral with at least one of the return guide and the end cap.

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