Motion guide device

Abstract

To avoid interference between a radial retainer and an axial retainer.SOLUTION: A motion guide device 1 comprises a radial retainer 40 that holds a plurality of first rolling elements 31 that receive a radial load among a plurality of rolling elements 30, and an axial retainer 50 that holds a plurality of second rolling elements 32 that receive an axial load, as retainers for holding the plurality of rolling elements 30 interposed between an inner ring 10 and an outer ring 20. A pair of bands 52, 53 of the axial retainer 50 are arranged on both radial sides of a plurality of partition walls 51 of the axial retainer 50, and of the pair of bands 52, 53, one band 53 that is arranged on the radial retainer 40 side has a smaller radial dimension than the other band 52 that is arranged on the opposite side of the radial retainer 40.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a motion guide device. [Background technology]

[0002] Patent Document 1 below discloses a compound roller type slewing bearing that can bear both thrust loads and radial loads. In this compound roller type slewing bearing, cylindrical rollers for bearing thrust loads and cylindrical rollers for bearing radial loads are arranged between an inner ring and an outer ring and are each held by a cage (see Figure 3). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 8-105438 Summary of the Invention [Problem to be solved by the invention]

[0004] In the motion guide device described above, a retainer (cage) is used to prevent contact between the rolling elements (cylindrical rollers) and to control the orientation of the rolling elements. The retainer is curved in the circumferential direction along the orbit of the rolling elements. Therefore, for molding purposes, the pair of bands of the radial retainer are arranged alternately in the radial direction. However, there is a possibility that the band arranged on the axial retainer side of the radial retainer may interfere with the axial retainer.

[0005] The present invention has been made in view of the above-mentioned problems, and has an object to avoid interference between a radial retainer and an axial retainer. [Means for solving the problem]

[0006] In order to solve the above problems, the motion guide device of the present invention comprises an inner ring, an outer ring, a plurality of rolling elements interposed between the inner ring and the outer ring, and a retainer that holds the plurality of rolling elements, wherein the retainer has a plurality of partition walls arranged between the plurality of rolling elements and a pair of bands that connect the plurality of partition walls circumferentially, and the retainer comprises a radial retainer that holds a plurality of first rolling elements that receive radial loads among the plurality of rolling elements, and an axial retainer that holds a plurality of second rolling elements that receive axial loads, wherein the pair of bands of the axial retainer are arranged on both radial sides of the plurality of partition walls of the axial retainer, and one of the pair of bands that is arranged on the radial retainer side has a smaller radial dimension than the other band that is arranged on the opposite side of the radial retainer. [Effects of the Invention]

[0007] According to the present invention, interference between the radial retainer and the axial retainer can be avoided. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view of a motion guide device according to an embodiment. [Figure 2] 1 is an exploded perspective view of a motion guide device according to an embodiment; [Figure 3] 1 is an enlarged cross-sectional view of a main part of a motion guide device according to an embodiment. [Figure 4] FIG. 2 is a plan view of an axial retainer according to one embodiment. [Figure 5] FIG. 5 is a cross-sectional view taken along the line V-V in FIG. [Figure 6] FIG. 2 is a plan view of a radial retainer according to one embodiment. [Figure 7] FIG. 7 is a cross-sectional view taken along the line VII-VII shown in FIG. [Figure 8] 10A and 10B are diagrams illustrating the operation of a motion guide device according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0010] Fig. 1 is a perspective view of a motion guide device 1 according to one embodiment. Fig. 2 is an exploded perspective view of the motion guide device 1 according to one embodiment. As shown in Fig. 1, the motion guide device 1 includes an inner ring 10 and an outer ring 20. The inner ring 10 and the outer ring 20 are formed in an annular shape having a common central axis O, and are combined to be capable of relative rotation.

[0011] In the following description, the direction in which the central axis O extends is referred to as the axial direction. The direction perpendicular to the direction in which the central axis O extends is referred to as the radial direction. The direction going around the central axis O is referred to as the circumferential direction.

[0012] The inner ring 10 and the outer ring 20 have a plurality of holes formed in the axial direction, each of which can be attached to an object (not shown). The inner ring 10 is configured to be separable into a first ring member 11 and a second ring member 12 in the axial direction. The first ring member 11 and the second ring member 12 are fastened together by bolts (not shown) inserted through some of the holes.

[0013] 2, the motion guide device 1 includes a plurality of rolling elements 30 interposed between the inner ring 10 and the outer ring 20, and a radial retainer 40 and an axial retainer 50 that hold the plurality of rolling elements 30. The rolling elements 30 are cylindrical rollers, and in this embodiment, are provided in three rows between the inner ring 10 and the outer ring 20.

[0014] FIG. 3 is an enlarged cross-sectional view of a main part of the motion guide device 1 according to one embodiment. 3, a flange 21 that protrudes radially inward (toward the right on the paper surface) is provided on the inner wall surface of the outer ring 20. The flange 21 is formed in an annular shape.

[0015] A rolling surface 21a of the rolling element 30 is formed on the tip surface of the flange 21 facing inward in the radial direction (to the right on the page). A rolling surface 12a is formed on the second ring member 12, facing the rolling surface 21a of the flange 21 across a gap in the radial direction. The rolling surface 12a is formed below the mating surface 13 of the first ring member 11 and the second ring member 12.

[0016] A plurality of first rolling elements 31 that receive a radial load are disposed between the rolling surfaces 21a and 12a. The rotation axis of each first rolling element 31 extends in the axial direction, and the peripheral surface of each first rolling element 31 rolls in the circumferential direction while contacting at least one of the rolling surfaces 21a and 12a.

[0017] The radial retainer 40 has a plurality of partition walls 41 arranged between the plurality of first rolling elements 31, and a pair of bands 42, 43 that connect the plurality of partition walls 41 in the circumferential direction. The radial retainer 40 prevents the first rolling elements 31 from contacting each other and also controls the attitude of the first rolling elements 31.

[0018] Furthermore, rolling surfaces 21b of the rolling elements 30 are formed on the surfaces of flange 21 facing both axial sides (upper and lower sides of the paper). First ring member 11 is formed with a first opposing flange 14 that faces flange 21 across a gap in the axial direction. First opposing flange 14 is formed with a rolling surface 14a that faces rolling surface 21b of flange 21 across a gap in the axial direction.

[0019] A plurality of second rolling elements 32 that receive axial loads are disposed between the rolling surfaces 21b and 14a. The rotation axes of the second rolling elements 32 extend in the radial direction, and the peripheral surfaces of the second rolling elements 32 roll in the circumferential direction while contacting at least one of the rolling surfaces 21b and 14a.

[0020] The axial retainer 50 has a plurality of partition walls 51 arranged between the plurality of second rolling elements 32, and a pair of bands 52, 53 that circumferentially connect the plurality of partition walls 51. The axial retainer 50 prevents the second rolling elements 32 from contacting each other and also controls the attitude of the second rolling elements 32.

[0021] The second ring member 12 is formed with a second opposing flange 15 that faces the flange 21 across a gap in the axial direction. The second opposing flange 15 is formed with a rolling surface 15a that faces the rolling surface 21b of the flange 21 across a gap in the axial direction. Similar to the area between the rolling surfaces 21b and 14a, a plurality of second rolling elements 32 are arranged between the rolling surfaces 21b and 15a, which are held by the axial retainer 50 and receive the load in the axial direction.

[0022] 4 is a plan view of an axial retainer 50 according to one embodiment. FIG. 5 is a cross-sectional view taken along line VV shown in FIG. 4, the axial retainer 50 is formed by connecting arc-shaped retainer members 50a in an annular shape. The retainer members 50a are, for example, resin molded parts.

[0023] The bands 52, 53 of the axial retainer 50 are arranged on both radial sides of the multiple partition walls 51. As shown in Fig. 5, the bands 52, 53 are arranged substantially point-symmetrically with respect to the center of the partition wall 51. By arranging the bands 52, 53 in this manner, the molding die (not shown) for the retainer member 50a can be removed in the axial direction (the vertical direction on the paper).

[0024] Of the bands 52, 53, the band 53 arranged on the radial retainer 40 side (right side of the drawing) has a smaller radial dimension than the band 52 arranged on the opposite side (left side of the drawing) from the radial retainer 40. Specifically, the radial dimension L21 of the band 53 is about 1 / 2 to 2 / 3 of the radial dimension L11 of the band 52.

[0025] On the other hand, the axial dimension L22 of band 53 is larger than the axial dimension L12 of band 52. This is to make the cross-sectional area of ​​band 53 approximately equal to the cross-sectional area of ​​band 52. By making the cross-sectional areas of bands 52, 53 approximately equal, the strength of bands 52, 53 is made approximately uniform, eliminating problems such as only one band breaking when subjected to a tensile load. Note that "approximately equal" here means that the difference in the cross-sectional areas of bands 52, 53 is within a range of ±5%, preferably ±3%, and more preferably ±1%.

[0026] A plurality of protrusions 54 are formed on the end faces of both axial sides (upper and lower sides on the page) of the partition wall 51. The protrusions 54 are formed in a hemispherical shape and are provided in pairs spaced apart in the radial direction. The protrusions 54 come into point contact with the rolling surfaces 21b, 14a, and 15a, suppressing heat generation due to wear and friction of the axial retainer 50. Note that if there is only one protrusion 54, the axial retainer 50 may tilt around that protrusion 54, so it is preferable to have two or more protrusions 54.

[0027] Fig. 6 is a plan view of a radial retainer 40 according to one embodiment. Fig. 7 is a cross-sectional view taken along line VII-VII shown in Fig. 6. 6, the radial retainer 40 is formed by connecting arc-shaped retainer members 40a in an annular shape. The retainer members 40a are, for example, resin molded parts.

[0028] 7, the bands 42, 43 of the radial retainer 40 are arranged on both sides of the multiple partition walls 41 in the axial direction (upper and lower sides on the paper). The bands 42, 43 are arranged offset in the radial direction. Specifically, the band 43 is arranged in the center of the partition wall 41 in the radial direction. Furthermore, the band 42 is arranged on the axial retainer 50 side of the partition wall 41 in the radial direction (left side on the paper).

[0029] The radial dimension L3 and cross-sectional area of ​​the bands 42, 43 are equal to each other. This allows the strength of the bands 42, 43 to be uniform. Meanwhile, the bands 42, 43 are offset in the radial direction by a dimension L4 that is larger than the dimension L3. By arranging the bands 42, 43 in this manner, the molding die (not shown) for the retainer member 40a can be removed in the axial direction (up and down on the page).

[0030] FIG. 8 is a diagram illustrating the operation of the motion guide device 1 according to one embodiment. As shown in Fig. 8, for the convenience of molding as described above, the bands 42, 43 of the radial retainer 40 are staggered in the radial direction. Furthermore, when the bands 52, 53 of the axial retainer 50 are arranged point-symmetrically with respect to the center of the partition wall 41 as in this embodiment, if the bands 52, 53 have a symmetrical shape as shown by the two-dot chain line in Fig. 8, there is a possibility that the axial retainer 50 and the radial retainer 40 will interfere with each other. For this reason, in this embodiment, the bands 52, 53 are asymmetrical in shape, so that the band 53 arranged on the radial retainer 40 side has a smaller radial dimension than the band 52 arranged on the opposite side of the radial retainer 40, thereby making it possible to avoid interference between the axial retainer 50 and the radial retainer 40.

[0031] As described above, the motion guide device 1 of this embodiment includes the inner ring 10, the outer ring 20, a plurality of rolling elements 30 interposed between the inner ring 10 and the outer ring 20, and a retainer that holds the plurality of rolling elements 30. The retainer has a plurality of partition walls arranged between the plurality of rolling elements 30 and a pair of bands that connect the plurality of partition walls in the circumferential direction. The retainer also includes a radial retainer 40 that holds a plurality of first rolling elements 31 that receive a radial load among the plurality of rolling elements 30. and an axial retainer 50 that holds a plurality of second rolling elements 32 that receive axial loads, and a pair of bands 52, 53 of the axial retainer 50 are arranged on both radial sides of a plurality of partition walls 51 of the axial retainer 50, and of the pair of bands 52, 53, one band 53 arranged on the radial retainer 40 side has a smaller radial dimension than the other band 52 arranged on the opposite side from the radial retainer 40. With this configuration, interference between the radial retainer 40 and the axial retainer 50 can be avoided.

[0032] In this embodiment, the cross-sectional area of ​​one band 53 is approximately equal to the cross-sectional area of ​​the other band 52. This configuration makes the strength of the bands 52 and 53 approximately uniform, eliminating problems such as only one band breaking when subjected to a tensile load, for example.

[0033] In this embodiment, at least one of the plurality of partition walls 51 of the axial retainer 50 has a plurality of protrusions 54 on its axial end surface. With this configuration, the protrusions 54 come into point contact with the rolling surfaces 21b, 14a, and 15a, thereby suppressing heat generation due to wear and friction of the axial retainer 50.

[0034] In addition, in this embodiment, the pair of bands 42, 43 of the radial retainer 40 are disposed on both axial sides of the multiple partition walls 41 of the radial retainer 40 and are disposed with a radial offset. With this configuration, the molding die used to mold the radial retainer 40 can be removed in the axial direction.

[0035] While the preferred embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited to the above-described embodiments. The shapes and combinations of the components shown in the above-described embodiments are merely examples, and various modifications can be made based on design requirements, etc., without departing from the spirit of the present invention. [Explanation of symbols]

[0036] REFERENCE SIGNS LIST 1...motion guide device, 10...inner ring, 11...first ring member, 12...second ring member, 12a...rolling surface, 13...matching surface, 14...first opposing flange, 14a...rolling surface, 15...second opposing flange, 15a...rolling surface, 20...outer ring, 21...flange, 21a...rolling surface, 21b...rolling surface, 30...rolling element, 31...first rolling element, 32...second rolling element , 40...radial retainer, 40a...retainer member, 41...partition wall, 42...band, 43...band, 50...axial retainer, 50a...retainer member, 51...partition wall, 52...band, 53...band, 54...protrusion, L3...dimension, L4...dimension, L11...dimension, L12...dimension, L21...dimension, L22...dimension, O...central axis

Claims

1. The bearing comprises an inner ring, an outer ring, a plurality of rolling elements interposed between the inner ring and the outer ring, and a retainer that holds the plurality of rolling elements, the retainer includes a plurality of partition walls arranged between the plurality of rolling elements, and a pair of bands connecting the plurality of partition walls in a circumferential direction, the retainer includes a radial retainer that holds a plurality of first rolling elements that receive a load in a radial direction among the plurality of rolling elements, and an axial retainer that holds a plurality of second rolling elements that receive a load in an axial direction, the pair of bands of the axial retainer are arranged on both radial sides of the plurality of partition walls of the axial retainer, and one of the pair of bands arranged on the radial retainer side has a smaller radial dimension than the other band arranged on the opposite side of the radial retainer; Motion guidance device.

2. The cross-sectional area of ​​the one band is approximately equal to the cross-sectional area of ​​the other band. The motion guide device according to claim 1 .

3. At least one of the plurality of partition walls of the axial retainer has a plurality of protrusions on an end surface in the axial direction. The motion guide device according to claim 1 or 2.

4. the pair of bands of the radial retainer are arranged on both sides of the plurality of partition walls of the radial retainer in the axial direction and are arranged offset in the radial direction; The motion guide device according to claim 1 or 2.

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