Retainer for thrust roller bearing, and thrust roller bearing

Abstract

The retainer for the thrust roller bearing comprises a first surface and a second surface which are respectively positioned in the thickness direction, is composed of a single plate-shaped member, and accommodates and retains the rollers in pockets. A retainer for thrust roller bearings is provided with: a pair of annular parts disposed at a distance from each other in the radial direction; and a plurality of pillar parts connecting the pair of annular parts so as to form a plurality of pockets arranged at intervals in the circumferential direction. The column portion is provided with a recessed portion recessed toward the first surface side in a central region in the rolling axis direction of the rollers accommodated in the pockets. The first surface side of the first side wall surface of the column part provided with the concave part is provided with a first roller anti-falling part, and the first roller anti-falling part protrudes towards the pocket side and prevents the roller from falling off from the first surface side. A second roller retaining portion is provided on a second surface side of a second side wall surface of the pillar portion in an end region in the rolling axis direction at a position away from the recess, and the second roller retaining portion protrudes toward the pocket side to prevent the roller from falling off from the second surface side.

Description

Technical Field

[0001] The present disclosure relates to a thrust roller bearing retainer and a thrust roller bearing. This application claims priority based on Japanese application No. 2022-115248 filed on July 20, 2022, and all the contents described in the above Japanese application are cited by reference. Background Art

[0002] A thrust needle roller bearing including a retainer retaining a needle roller is known (see, for example, Patent Document 1). The retainer included in the thrust needle roller bearing disclosed in Patent Document 1 is provided with a plurality of pockets. Furthermore, the retainer of Patent Document 1 is divided into three regions in the direction along the side surface of the pocket, and adjacent regions are integrally formed in a state of being bent in a manner facing opposite sides in the thickness direction of the retainer body.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2004-84797 Summary of the invention

[0006] Problems to be solved by the invention

[0007] In recent years, thrust roller bearings have been used with extremely small roller diameters in order to achieve a low cross-sectional height. Even in this case, it is required to prevent the strength of the retainer from decreasing and the rollers from falling out of the retainer, that is, a high roller retention force is required.

[0008] Therefore, one of the objects of the present invention is to provide a thrust roller bearing cage which achieves a low cross-sectional height and prevents a decrease in strength, and also improves the holding force of the rollers.

[0009] Technical means of solving problems

[0010] The thrust roller bearing retainer disclosed in the present invention includes a first surface and a second surface respectively located in the thickness direction, and is composed of a plate-like member, which accommodates and retains the roller in the pocket. The thrust roller bearing retainer has: a pair of annular portions, which are arranged at intervals in the radial direction; and a plurality of column portions, which connect the pair of annular portions to form a plurality of pockets arranged at intervals in the circumferential direction. On the column portion, a recessed portion recessed toward the first surface is provided in the central area in the rolling axis direction of the roller accommodated in the pocket. A first roller anti-slip portion is provided on the first surface side of the first side wall surface of the column portion where the recess is provided, and the first roller anti-slip portion protrudes toward the pocket side to prevent the roller from falling off from the first surface side. A second roller anti-slip portion is provided on the second surface side of the second side wall surface of the column portion in a position avoiding the recess and in the end area in the rolling axis direction, and the second roller anti-slip portion protrudes toward the pocket side to prevent the roller from falling off from the second surface side.

[0011] Effects of the Invention

[0012] According to the above-mentioned thrust roller bearing cage, it is possible to achieve a low cross-sectional height and prevent a decrease in strength, and also to improve the holding force of the rollers. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic perspective view showing a thrust roller bearing cage in Embodiment 1 of the present disclosure.

[0014] Figure 2 It means in Figure 1 A schematic perspective view of a thrust roller bearing retainer showing a state where rollers are accommodated in pockets.

[0015] Figure 3 Observed from the thickness direction Figure 1 A schematic plan view of a thrust roller bearing retainer is shown.

[0016] Figure 4 yes Figure 3 An enlarged view of the portion shown in area IV.

[0017] Figure 5 Is Figure 4 A schematic cross-sectional view of the state after cutting at the cross section indicated by arrow VV in FIG.

[0018] Figure 6 Yes Figure 1 A schematic perspective view of a thrust roller bearing with a cage shown.

[0019] Figure 7 Yes means Figure 6 A schematic cross-sectional view of a portion of a thrust roller bearing is shown.

[0020] Figure 8This is a schematic plan view of the thrust roller bearing cage according to the second embodiment as viewed from the thickness direction.

[0021] Fig. 9 yes Figure 8 An enlarged view of the portion shown in Area IX.

[0022] Fig.10 Is Fig. 9 A schematic cross-sectional view of the state after cutting along the cross section indicated by arrow XX in FIG. DETAILED DESCRIPTION

[0023] [Overview of Embodiments]

[0024] The thrust roller bearing retainer disclosed in the present invention includes a first surface and a second surface respectively located in the thickness direction, and is composed of a plate-like member, which accommodates and retains the roller in the pocket. The thrust roller bearing retainer has: a pair of annular portions, which are arranged at intervals in the radial direction; and a plurality of column portions, which connect the pair of annular portions to form a plurality of pockets arranged at intervals in the circumferential direction. On the column portion, a recessed portion recessed toward the first surface is provided in the central area in the rolling axis direction of the roller accommodated in the pocket. A first roller anti-slip portion is provided on the first surface side of the first side wall surface of the column portion where the recess is provided, and the first roller anti-slip portion protrudes toward the pocket side to prevent the roller from falling off from the first surface side. A second roller anti-slip portion is provided on the second surface side of the second side wall surface of the column portion in a position avoiding the recess and in the end area in the rolling axis direction, and the second roller anti-slip portion protrudes toward the pocket side to prevent the roller from falling off from the second surface side.

[0025] The inventors of the present invention have recently considered the following regarding thrust bearings used when bearing loads in the thrust direction. When a low cross-sectional height is required, that is, when the thickness dimension in the thrust direction is reduced, sliding bearings without rolling elements have been mostly used so far. However, the focus is on situations where it is impossible to maintain a low cross-sectional height and the rollers need to be used to properly bear the load. In addition, in order to achieve a low cross-sectional height, in-depth research has been conducted on the development of thrust roller bearings with extremely small roller diameters and thrust roller bearing retainers for the thrust roller bearings. Here, for example, in the case of reducing the roller diameter and properly retaining the rollers, it is considered to prepare a plate-shaped retainer, bend the side of the pocket as shown in Patent Document 1, and make the portion function as a roller anti-slip portion to prevent the roller from falling out of the pocket. That is, it is a method of making the surface in the thickness direction of the retainer face the rolling surface side of the roller and function as a roller anti-slip portion. However, when the roller diameter is extremely small, such a method requires that the side of the pocket be bent to a size smaller than the thickness of the retainer to form the roller anti-slipping member, which requires high precision and is extremely difficult to process. In addition, in order to easily form the roller anti-slipping portion by bending, the thickness of the retainer must be reduced, resulting in a decrease in the strength of the retainer.

[0026] In the thrust roller bearing retainer disclosed in the present invention, a recessed portion that is recessed toward the first surface is provided on the column portion in the central region in the rolling axis direction of the roller accommodated in the pocket. A first roller anti-slip portion is provided on the first surface side of the first side wall surface of the column portion provided with the recess, and the first roller anti-slip portion protrudes toward the pocket side to prevent the roller from falling off from the first surface side. A second roller anti-slip portion is provided on the second surface side of the second side wall surface of the column portion at a position avoiding the recess and in the end region in the rolling axis direction, and the second roller anti-slip portion protrudes toward the pocket side to prevent the roller from falling off from the second surface side.

[0027] The first roller anti-slipping part and the second roller anti-slipping part thus provided can form a part of the side wall surface of the pocket by processing such as pressing, and therefore are easier to process than when the roller anti-slipping part is formed by bending. In addition, from the viewpoint of accuracy, it can also be reliably made to protrude toward the pocket side and function as a roller anti-slipping part. That is, in the thrust roller bearing retainer disclosed in the present invention, the surface of the retainer in the thickness direction is not made to face the rolling surface of the roller to function as a roller anti-slipping part, but a part of the side wall surface of the pocket that intersects with the surface of the retainer in the thickness direction, i.e., faces the rolling surface side of the roller, to function as a roller anti-slipping part. In addition, according to such a structure, the amount of depression when forming the recess in the thickness direction of the retainer can be adjusted according to the diameter of the roller and the thickness of the retainer. In this way, the thickness of the retainer can be thickened, and the roller can be prevented from falling off in the thickness direction of the retainer on the side wall surface of the pocket. Therefore, the holding force of the roller can be improved. As described above, according to such a thrust roller bearing cage, it is possible to achieve a low cross-sectional height and prevent a decrease in strength, and also to improve the holding force of the rollers.

[0028] In the above-mentioned thrust roller bearing retainer, a slit penetrating in the thickness direction may be provided next to the concave portion in the rolling axis direction. When such a slit is formed, the central region in the rolling axis direction can be separated from the end region, so that the central region in the rolling axis direction can be easily deformed and the above-mentioned concave portion can be easily formed. Therefore, it is possible to achieve an improvement in productivity.

[0029] In the above-mentioned retainer for thrust roller bearing, a pair of second roller anti-slipping parts may be provided in the two end regions in the rolling axis direction. In this way, the posture of the roller accommodated in the pocket can be stabilized by the first roller anti-slipping part provided in the central region in the rolling axis direction and the pair of second roller anti-slipping parts provided in the two end regions in the rolling axis direction. Therefore, the roller can roll more smoothly.

[0030] In the above-mentioned retainer for thrust roller bearing, at least one of the first side wall surface and the second side wall surface may include an arc-shaped portion along the rolling surface of the roller. In this way, the possibility of the rolling surface of the roller being hooked on the side wall surface of the pocket when the roller rolls is reduced, and the roller can roll more smoothly.

[0031] In the above thrust roller bearing retainer, the thickness of the retainer can be 40% or more relative to the roller diameter, so that the so-called cross-sectional height can be reduced, and the thickness of the retainer can be sufficiently increased, thereby maintaining the high strength of the retainer.

[0032] In the above thrust roller bearing retainer, the thickness of the retainer may be 60% or less relative to the diameter of the roller. This can prevent the retainer provided with the recessed portion from interfering with the raceway located in the thrust direction.

[0033] In the thrust roller bearing retainer, the diameter of the roller accommodated in the pocket may be 0.4 mm or more and 3.0 mm or less. This can make the retaining force of the roller with a very small diameter sufficiently high and reduce the possibility of the strength of the retainer being reduced.

[0034] The thrust roller bearing disclosed in the present invention comprises: the above-mentioned retainer for thrust roller bearing; a plurality of rollers respectively accommodated in a plurality of pockets; and a raceway ring having a raceway surface on which the rollers roll. Such a thrust roller bearing improves the retaining force of the rollers and maintains the strength of the retainer, and can therefore be effectively used in situations where a particularly low cross-sectional height is required and the rollers are required to bear thrust loads.

[0035] [Specific example of embodiment]

[0036] Next, an example of a specific embodiment of the thrust roller bearing retainer disclosed in the present disclosure will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals and their description will not be repeated.

[0037] (Implementation Method 1)

[0038] First, Embodiment 1 which is an embodiment of the present disclosure will be described. Figure 1 It is a schematic perspective view showing a thrust roller bearing cage (hereinafter, sometimes simply referred to as a “cage”) in Embodiment 1 of the present disclosure. Figure 2 It means in Figure 1 A schematic perspective view of a thrust roller bearing retainer showing a state in which rollers are accommodated in pockets. Figure 3 Observed from the thickness direction Figure 1 A schematic plan view of a thrust roller bearing retainer is shown. Figure 4 yes Figure 3 An enlarged view of the portion shown in area IV. Figure 5 Is Figure 4 A schematic cross-sectional view of the situation after the section indicated by the arrow VV in FIG. Figure 5 The figure shows a roller housed in a pocket. Figure 1 In the following figures, the Z direction indicates the thickness direction of the retainer. The X direction and the Y direction indicate the radial direction from the center of the retainer when viewed from the thickness direction. The X direction is a direction orthogonal to the Y direction on a plane perpendicular to the thickness direction.

[0039] Reference Figure 1 to Figure 5The thrust roller bearing retainer 11a of the first embodiment of the present disclosure is composed of a plate-shaped member. Examples of the material of the retainer 11a include SPCC, SUS301, and SUS304. The retainer 11a accommodates and retains the roller 41a in the pocket 18a.

[0040] The retainer 11a is in the shape of a disk, and has a circular through hole 12a at the center. A shaft (not shown) supported by a thrust roller bearing including the retainer 11a is disposed in the through hole 12a.

[0041] The retainer 11a includes a first surface 13a and a second surface 14a respectively located in the thickness direction. That is, the retainer 11a includes the first surface 13a and the second surface 14a arranged at intervals in the thickness direction. The retainer 11a includes a pair of annular portions 15a, 16a and a plurality of columnar portions 17a connecting the pair of annular portions 15a, 16a. The annular portion 15a is arranged on the inner diameter side, and the annular portion 16a is arranged on the outer diameter side. Figure 3 The double-dotted dashed line in represents the boundary between a pair of annular portions 15a, 16a and the column portion 17a. A plurality of column portions 17a connect a pair of annular portions 15a, 16a to form a plurality of pockets 18a arranged at intervals in the circumferential direction. That is, a plurality of pockets 18a are formed at intervals in the circumferential direction on the retainer 11a. A roller 41a is accommodated in each pocket 18a. In the present embodiment, when viewed from the thickness direction of the retainer 11a, a plurality of pockets 18a are radially arranged from the center 19a of the through hole 12a. That is, the rolling axis direction of the roller 41a extends radially. In addition, each column portion 17a is configured so that the circumferential width increases toward the outer diameter side.

[0042] The roller 41a accommodated in the pocket 18a is, for example, a needle roller. The diameter D1 of the roller 41a, i.e., the diameter of the roller 41a, is 0.4 mm or more and 3.0 mm or less. Specifically, for example, 1 mm is selected as the diameter D1 of the roller 41a. If such a roller 41a is used, the thickness of the retainer 11a in the thickness direction (Z direction) can be reduced, and a low cross-sectional height can be achieved. In addition, as the length of the roller 41a in the rolling axis direction, 5.0 mm is selected, for example.

[0043] The thickness T1 of the retainer 11a, that is, the distance between the first surface 13a and the second surface 14a in the thickness direction of the retainer 11a, is 40% or more of the diameter D1 of the roller 41a. In addition, the thickness T1 of the retainer 11a is 60% or less of the diameter D1 of the roller 41a. In this embodiment, as the thickness T1 of the retainer 11a, for example, 0.4 mm is selected.

[0044] In the retainer 11a, a recessed portion 21a is provided in the column portion 17a, which is recessed in the thickness direction. The recessed portion 21a is formed to be recessed toward the first surface 13a. In this case, for example, the recessed portion 21a is formed by pressing the retainer 11a from the second surface 14a in the direction opposite to the arrow Z using a clamp or the like at a position where the recessed portion 21a is desired to be provided. The recessed portion 21a is provided in the central area of ​​the column portion 17a in the rolling axis direction of the roller 41a. Figure 4 In the embodiment, the rolling axis direction of the roller 41a is the direction indicated by the arrow Y. Regarding the amount of depression of the recessed portion 21a, Figure 5 The length T2 in denoted that, in the present embodiment, 0.3 mm is selected as the length T2. That is, the cross-sectional height T3 of the retainer 11a after adding the thickness T1 of the retainer 11a + the length T2 of the recess amount is 0.7 mm in the present embodiment. In addition, as described above, the recess 21a can be formed by pressing only from the second surface 14a side using a clamp or the like, so it can be easily formed and its recess amount can be easily adjusted. In addition, grease can be accumulated in the space 22a on the second surface 14a constituting the recess 21a. Therefore, grease can be continuously supplied to the rolling surface 42a of the roller 41a for a long time, and the smooth rolling of the roller 41a can be achieved for a long time.

[0045] In the retainer 11a, slits 23a and 24a are provided that penetrate in the thickness direction beside the recessed portion 21a in the rolling axis direction of the roller 41a. In the present embodiment, the slits 23a and 24a are provided on both sides of the recessed portion 21a in the Y direction. Each slit 23a and 24a is formed to be long in a direction perpendicular to the rolling axis direction of the roller 41a. In the present embodiment, before the recessed portion 21a is formed, the regions corresponding to the slits 23a and 24a are punched out in the thickness direction to form the slits 23a and 24a.

[0046] Here, a first roller anti-slip portion 32a is provided on the first surface 13a side of the first side wall surface 31a of the column portion 17a provided with the recessed portion 21a, and the first roller anti-slip portion 32a protrudes toward the pocket 18a side to prevent the roller 41a from falling off from the first surface 13a side. The first roller anti-slip portion 32a is provided on two first side wall surfaces 31a located on both sides of the circumferential direction of the pocket 18a. The first side wall surface 31a includes an arc-shaped portion along the rolling surface 42a of the roller 41a. In the arc-shaped portion, the protruding portion located on the first surface 13a side becomes the first roller anti-slip portion 32a. By having such an arc-shaped portion, the possibility of the rolling surface 42a of the roller 41a being hooked with the first side wall surface 31a of the pocket 18a when the roller 41a rolls can be reduced, and the roller 41a can be further made to roll smoothly. Furthermore, when viewed from the thickness direction (Z direction), each of the two first side wall surfaces 31 a has a linear shape along the rolling axis direction of the roller 41 a .

[0047] In addition, at the position avoiding the recessed portion 21a and at the two end regions in the rolling axis direction, the second roller anti-slipping portions 35a and 36a are provided on the second surface 14a side of the second side wall surfaces 33a and 34a of the column portion 17a, and the second roller anti-slipping portions 35a and 36a protrude toward the pocket 18a side to prevent the roller 41a from falling off from the second surface 14a side. That is, a pair of second roller anti-slipping portions 35a and 36a are provided at the two end regions in the rolling axis direction. The second roller anti-slipping portions 35a and 36a are respectively provided on the two second side wall surfaces 33a and 34a located on both sides of the circumferential direction of the pocket 18a. The second side wall surfaces 33a and 34a include an arc-shaped portion along the rolling surface 42a of the roller 41a. In the arc-shaped portion, the protruding portion located on the second surface 14a side becomes the second roller anti-slipping portions 35a and 36a. By having such an arc-shaped portion, the possibility of the rolling surface 42a of the roller 41a and the second side wall surfaces 33a, 34a of the pocket 18a being caught when the roller 41a rolls can be reduced, and the roller 41a can roll more smoothly. In addition, when viewed from the thickness direction (Z direction), the two second side wall surfaces 33a, 34a are straight lines along the rolling axis direction of the roller 41a.

[0048] If an example of a method for manufacturing such a retainer 11a is briefly described, it is as follows. First, a disc-shaped member having a through hole 12a provided in the center is prepared. Then, the disc-shaped member is punched in the thickness direction in such a manner as to form the pockets 18a and the slits 23a, 24a. Then, the central area of ​​each pocket 18a in the rolling axis direction is pressed from the second surface 14a side to the first surface 13a side to form the recess 21a. Then, the first roller anti-slip portion 32a is formed on the first side wall surface 31a. In this case, a member having a shape along the rolling surface 42a of the roller 41a is pressed against the first side wall surface 31a from the second surface 14a side to plastically deform the first side wall surface 31a, and an arc-shaped portion and the first roller anti-slip portion 32a are formed on the first side wall surface 31a. In addition, the second roller anti-slip portions 35a, 36a are formed on the second side wall surfaces 33a, 34a. In this case, the second side wall surfaces 33a and 34a are respectively pressed from the first surface 13a side with a member having a shape along the rolling surface 42a of the roller 41a to plastically deform the second side wall surfaces 33a and 34a, and arc-shaped portions and second roller disengagement prevention portions 35a and 36a are formed on the second side wall surfaces 33a and 34a. The retainer 11a of the above structure is manufactured in this way. In addition, after that, each of the pockets 18a accommodates one roller 41a and is installed between the raceways arranged in the thickness direction, thereby assembling the thrust roller bearing.

[0049] According to the retainer 11a having such a structure, the first roller anti-slipping portion 32a and the second roller anti-slipping portion 35a, 36a provided can be formed by pressing or other processing to form a part of the first side wall surface 31a and the second side wall surface 33a, 34a of the pocket 18a, so that the processing is easier than forming the roller anti-slipping portion by bending. In addition, from the viewpoint of accuracy, it can also be reliably made to protrude toward the pocket 18a side and function as a roller anti-slipping portion. In addition, according to such a structure, the amount of depression when the recessed portion 21a is formed in the thickness direction of the retainer 11a can be adjusted according to the diameter of the roller 41a and the thickness of the retainer 11a. In this way, the thickness of the retainer 11a can be increased, and the roller 41a can be prevented from falling off in the thickness direction of the retainer 11a on the first side wall surface 31a and the second side wall surface 33a, 34a of the pocket 18a. Therefore, the holding force of the roller 41a can be improved. As described above, according to the thrust roller bearing retainer 11 a , it is possible to achieve a low cross-sectional height and prevent a decrease in strength, and also to improve the retaining force of the rollers 41 a .

[0050] In this embodiment, slits 23a and 24a are provided next to the concave portion 21a in the rolling axis direction. When such slits 23a and 24a are formed, the central area in the rolling axis direction can be separated from the end areas, so that the central area in the rolling axis direction can be easily deformed and the concave portion 21a can be easily formed. Therefore, productivity can be improved.

[0051] In this embodiment, a pair of second roller anti-slip portions 35a and 36a are provided in the two end regions in the rolling axis direction. Therefore, the posture of the roller 41a accommodated in the pocket 18a can be stabilized by the first roller anti-slip portion 32a provided in the central region in the rolling axis direction and the pair of second roller anti-slip portions 35a and 36a provided in the two end regions in the rolling axis direction. Therefore, the roller 41a can be further smoothly rolled.

[0052] In this embodiment, the thickness of the retainer 11a is 40% or more relative to the diameter of the roller 41a. Therefore, the so-called cross-sectional height can be reduced, and the thickness of the retainer 11a can be sufficiently thickened, and the high strength of the retainer 11a can be maintained. In addition, the thickness of the retainer 11a is 60% or less relative to the diameter of the roller 41a. Therefore, the retainer 11a provided with the recessed portion 21a can be prevented from interfering with the raceway located in the thrust direction.

[0053] In this embodiment, the diameter of the roller 41a accommodated in the pocket 18a is 0.4 mm to 3.0 mm. Such a retainer 11a can sufficiently increase the retaining force of the roller 41a having an extremely small diameter and can reduce the possibility of a decrease in the strength of the retainer 11a.

[0054] Next, the structure of the thrust roller bearing including the above-mentioned cage 11 a will be described. Figure 6 Yes Figure 1 FIG. 1 is a schematic perspective view of a thrust roller bearing of a cage 11 a shown. Figure 7 Yes means Figure 6 A schematic cross-sectional view of a portion of a thrust roller bearing is shown.

[0055] Refer to Figure 6 and Figure 7 , the thrust roller bearing 50a comprises: Figure 1 The retainer 11a shown in the figure; the plurality of rollers 41a respectively accommodated in the plurality of pockets 18a; the first raceway ring 53a having the first raceway surface 51a on which the rollers 41a roll; and the second raceway ring 54a having the second raceway surface 52a on which the rollers 41a roll. The first raceway surface 51a and the second raceway surface 52a are both planes. The first raceway ring 53a and the second raceway ring 54a are both disk-shaped, and through holes 55a and 56a are formed in the center of the radial direction and penetrate in the thickness direction, respectively. A shaft (not shown) supported by a thrust roller bearing is arranged in the through holes 12a, 55a, and 56a. The first raceway ring 53a, the second raceway ring 54a and the retainer 11a are arranged concentrically. The first raceway ring 53a and the second raceway ring 54a are arranged on both sides of the retainer 11a in the thickness direction. The center of the retainer 11a coincides with the center of the first raceway ring 53a and the center of the second raceway ring 54a. The roller 41a revolves around the center 19a as the rotation center while rolling (rotating) on ​​the first and second rolling surfaces 51a and 52a. The cage 11a rotates around the center 19a as the rotation center.

[0056] Such a thrust roller bearing 50a can achieve a low cross-sectional height and improve the holding force of the roller 41a while maintaining the strength of the cage 11a. Therefore, it can be effectively used when a particularly low cross-sectional height is required and the roller 41a is required to bear a thrust load.

[0057] (Implementation Method 2)

[0058] Next, another embodiment, that is, Embodiment 2, will be described. Figure 8 This is a schematic plan view of the thrust roller bearing cage according to the second embodiment as viewed from the thickness direction. Fig. 9 yes Figure 8 An enlarged view of the portion shown in Area IX. Fig.10 Is Fig. 9 A schematic cross-sectional view of the situation after the cross section indicated by the arrow XX in FIG. Fig.10The figure shows the rollers accommodated in the pockets. The thrust roller bearing retainer in the second embodiment basically has the same structure as the first embodiment and has the same effect. However, the structure of the column portion provided in the thrust roller bearing retainer in the second embodiment is different from that in the first embodiment.

[0059] Refer to Figure 8 , Fig. 9 as well as Fig.10 The retainer 11b in the second embodiment includes a first surface 13a and a second surface 14a located in the thickness direction. The retainer 11b includes a pair of annular portions 15a and 16a and a plurality of columnar portions 17b connecting the pair of annular portions 15a and 16a. Figure 8 The two-dot chain line in denoted the boundary between the pair of annular portions 15a, 16a and the column portion 17b. The plurality of column portions 17b connect the pair of annular portions 15a, 16a to form a plurality of pockets 18b arranged at intervals in the circumferential direction.

[0060] In the retainer 11b, a recessed portion 21b recessed in the thickness direction is provided on the column portion 17b. The recessed portion 21b is formed to be recessed on the first surface 13a side. A first roller anti-slip portion 32a is provided on the first surface 13a side of the first side wall surface 31a of the column portion 17b provided with the recessed portion 21b, and the first roller anti-slip portion 32a protrudes toward the pocket 18b side to prevent the roller 41a from falling off from the first surface 13a side. In addition, second roller anti-slip portions 35a and 36a are provided on the second surface 14a side of the second side wall surfaces 33a and 34a of the column portion 17a at a position avoiding the recessed portion 21a and at two end regions in the rolling axis direction, and the second roller anti-slip portions 35a and 36a protrude toward the pocket 18b side to prevent the roller 41a from falling off from the second surface 14a side.

[0061] Here, in the column portion 17b included in the retainer 11b, unlike the case of Embodiment 1, no slit penetrating in the thickness direction is provided next to the recessed portion 21b in the rolling axis direction of the roller 41a. That is, no slit is provided between the central region and the end region in the rolling axis direction of the roller 41a, but the first side wall surface 31a and the second side wall surfaces 33a and 34a are connected.

[0062] In such a thrust roller bearing retainer 11b, a low cross-sectional height can be achieved, and a reduction in strength can be prevented, and the retaining force of the roller 41a can be improved. In this case, since no slit is provided, the retaining force of the grease in the space 22b above the recess 21b can be improved.

[0063] (Other embodiments)

[0064] In addition, in the above-mentioned embodiment, the first side wall surface and the second side wall surface include arc-shaped portions, but are not limited thereto. For example, in addition to the portions provided with the first roller anti-slipping portion and the second roller anti-slipping portion, they may also be straight planes in the thickness direction. The first roller anti-slipping portion and the second roller anti-slipping portion may also be configured to have a convex shape protruding from the straight plane in the circumferential direction.

[0065] It should be understood that the embodiments disclosed this time are illustrative in all aspects and are not restrictive in any aspect. The scope of the present invention is defined by the claims, and is intended to include the meaning equivalent to the claims and all modifications within the scope.

[0066] Description of Reference Numerals

[0067] 11a, 11b retainer for thrust roller bearing; 12a, 55a, 56a through hole; 13a first surface; 14a second surface; 15a, 16a annular portion; 17a, 17b column portion; 18a pocket; 19a center; 21a, 21b recessed portion; 22a, 22b space; 23a, 24a slit; 31a first side wall surface; 32a first roller anti-slip portion; 33a, 34a second side wall surface; 35a, 36a second roller anti-slip portion; 41a roller; 42a rolling surface; 50a thrust roller bearing; 51a first raceway surface; 52a second raceway surface; 53a first raceway ring; 54a second raceway ring.

Claims

1. A retainer for a thrust roller bearing, wherein: The thrust roller bearing retainer includes a first surface and a second surface respectively located in the thickness direction, and is composed of a plate-like member, and accommodates and retains the roller in the pocket. The thrust roller bearing retainer has: a pair of annular portions arranged at intervals in the radial direction; and A plurality of column portions connecting the pair of annular portions to form a plurality of the pockets arranged at intervals in the circumferential direction; The column portion is provided with a recessed portion recessed toward the first surface in a central region in a rolling axis direction of the roller accommodated in the pocket. A first roller anti-slip portion is provided on the first surface side of the first side wall surface of the column portion provided with the recessed portion, and the first roller anti-slip portion protrudes toward the pocket side to prevent the roller from falling off from the first surface side. A second roller anti-slip portion is provided on the second surface side of the second side wall surface of the column portion at a position avoiding the recess and in the end area in the direction of the rolling axis, and the second roller anti-slip portion protrudes toward the pocket side to prevent the roller from falling off from the second surface side.

2. The thrust roller bearing retainer according to claim 1, wherein: A slit penetrating in the thickness direction is provided next to the recessed portion in the rolling axis direction.

3. The thrust roller bearing retainer according to claim 1 or 2, wherein: A pair of the second roller anti-slip portions are provided at two end regions in the rolling axis direction.

4. The thrust roller bearing retainer according to claim 1 or 2, wherein: At least one of the first side wall surface and the second side wall surface includes an arc-shaped portion along the rolling surface of the roller.

5. The thrust roller bearing retainer according to claim 1 or 2, wherein: The thickness of the retainer is 40% or more relative to the diameter of the roller.

6. The thrust roller bearing retainer according to claim 1 or 2, wherein: The thickness of the retainer is 60% or less of the diameter of the roller.

7. The thrust roller bearing retainer according to claim 1 or 2, wherein: The diameter of the roller accommodated in the pocket is greater than or equal to 0.4 mm and less than or equal to 3.0 mm.

8. A thrust roller bearing, in, include: The retainer for a thrust roller bearing according to claim 1 or 2; A plurality of rollers are respectively accommodated in the plurality of pockets; and a raceway ring having a raceway surface on which the rollers roll.

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