Cage, rolling bearing, and method for assembling rolling bearing

Abstract

A cage 14 comprises: a first wall facing a first end surface 26 of a roller 13 of a rolling bearing 10; a second wall facing a second end surface 27 of the roller 13; and a plurality of bars connecting the first wall to the second wall. A space between the first wall and the second wall and between a pair of the bars serves as a pocket 29 for accommodating the roller 13. The bars have, on at least one of a first side and a second side in a radial direction, a fall-off prevention portion for preventing the roller 13 accommodated in the pocket 29 from falling off. A connecting portion between the first wall and each of the bars has a first recessed surface 44 located on the first side in the radial direction, and a second recessed surface 43 located on the second side in the radial direction, the first recessed surface 44 being recessed more than the second recessed surface 43.

Description

Cage, rolling bearing, and method of assembling rolling bearing

[0001] The present invention relates to a cage, a rolling bearing, and a method for assembling a rolling bearing.

[0002] The rolling bearing has an inner ring, an outer ring, multiple rolling elements, and a cage that holds the multiple rolling elements. The cage has multiple pockets that accommodate the rolling elements. The cage disclosed in Patent Document 1 has a first annular body facing first end faces of the rollers, which are the rolling elements, a second annular body facing second end faces of the rollers, and multiple pillars connecting the first annular body and the second annular body. The space between the first annular body and the second annular body and between a pair of pillars forms the pocket that accommodates the rollers.

[0003] Japanese Patent Application Laid-Open No. 2021-143765

[0004] Figure 21 is a perspective view showing a portion of a conventional cage. Figure 22 is a view of pockets in the conventional cage, viewed along the axial direction of the rollers. Cage 90 has protrusions 92 as anti-fall-out portions that prevent rollers 99 housed in pockets 91 from falling out. Two protrusions 92 are located in one pocket 91. The dimension B between the two protrusions 92 is smaller than the diameter D of the rollers 99. Therefore, when the rollers 99 are fitted into the pockets 91, the rollers 99 press against the protrusions 92, causing elastic deformation of the pillars 93 of the cage 90. This causes stress concentration at the connection 95 between the pillars 93 and the annular body 94.

[0005] To alleviate the stress concentration, a recessed surface 96 is provided at a connection 95 between the pillar 93 and the annular body 94. The recessed surface 96 is formed over the entire length of the retainer 90, from the outer peripheral surface 97 to the inner peripheral surface 98. Because the recessed surface 96 is formed over a wide area, the thickness of the connection 95 becomes small, which may result in insufficient strength of the retainer 90.

[0006] Furthermore, recess surface 96 reduces the contact area between roller 99 and annular body 94. For manufacturing purposes, roller 99 has a recess 100 on the radially inner side of end face 99 a. End face 99 a of roller 99 contacts annular body 94, but if recess 100 is large and recess surface 96 is formed wide in the radial direction, the contact area between roller 99 and annular body 94 will be narrow. For this reason, particularly when cage 90 is made of resin, contact of end face 99 a of roller 99 is likely to cause wear to part of annular body 94.

[0007] Therefore, the present disclosure makes it possible to alleviate stress concentration that occurs when rollers are fitted into pockets in a cage of a rolling bearing, thereby making it possible to suppress wear due to contact with the rollers.

[0008] A retainer according to an embodiment of the present invention comprises a first wall facing a first end face of a roller of a rolling bearing, a second wall facing a second end face of the roller, and a plurality of pillars connecting the first wall and the second wall, wherein the space between the first wall and the second wall and between the pair of pillars forms a pocket for accommodating the roller, and the pillars have a fall prevention portion on at least one of a first radial side and a second radial side that prevents the rollers accommodated in the pocket from falling out, and the connection portion between the first wall and the pillars has a first concave surface located on the first radial side and a second concave surface located on the second radial side, and the first concave surface is more recessed than the second concave surface.

[0009] The cage of the present invention can reduce the stress concentration that occurs when the rollers are fitted into the pockets of the cage, and can suppress wear of the cage due to contact with the rollers.

[0010] FIG. 1 is a cross-sectional view showing an embodiment of a rolling bearing of the present invention. FIG. 2 is a perspective view of a cage. FIG. 3 is an explanatory diagram of rollers accommodated in pockets, viewed along the central axes of the rollers. FIG. 4 is a view from which the rollers are removed from the explanatory diagram shown in FIG. 3. FIG. 5 is an enlarged view of a portion of the cage. FIG. 6 is a cross-sectional view of a region of a first connection portion where a concave arc surface is formed, viewed in the radial direction of the cage. FIG. 7 is a cross-sectional view of a region of a first connection portion where a recess surface is formed, viewed in the radial direction of the cage. FIG. 8 is a perspective view showing a modified example of the cage shown in FIG. 5. FIG. 9 is a view for explaining the cage shown in FIG. 8, showing pockets as viewed along the central axes of the rollers. FIG. 10 is a cross-sectional view showing another embodiment of a rolling bearing. FIG. 11 is a perspective view of a cage included in the rolling bearing shown in FIG. 10. FIG. 12 is a perspective view showing a modified example of the cage shown in FIG. 11. FIG. 13 is a cross-sectional view showing another embodiment of a rolling bearing. Fig. 14 is a front view showing a portion of the rolling bearing shown in Fig. 13. Fig. 15 is a perspective view of a cage segment. Fig. 16 is a view showing a modified example of the cage shown in Fig. 8. Fig. 17 is a view showing a modified example of the cage shown in Fig. 9. Fig. 18 is an enlarged sectional view showing a portion of the rolling bearing. Fig. 19 is a view showing yet another modified example of the cage. Fig. 20 is a view showing yet another modified example of the cage shown in Figs. 11 and 12. Fig. 21 is a perspective view showing a portion of a conventional cage. Fig. 22 is a view of pockets that a conventional cage has, viewed along the axial direction of the rollers.

[0011] <Outline of Embodiments of the Present Invention> The following will list and describe outlines of embodiments of the present invention. (1) A cage according to an embodiment of the present invention comprises: a first wall facing first end faces of rollers of a rolling bearing, a second wall facing second end faces of the rollers, and a plurality of pillars connecting the first wall and the second wall, wherein a space between the first wall and the second wall and between the pair of pillars forms a pocket for accommodating the rollers, wherein the pillars have a drop-out prevention portion on at least one of a first side and a second side in the radial direction that prevents the rollers accommodated in the pocket from falling out, and a connection portion between the first wall and the pillars has a first concave surface located on the first side in the radial direction and a second concave surface located on the second side in the radial direction, and the first concave surface is recessed more than the second concave surface.

[0012] With this cage, in order to fit the roller into the pocket, the roller presses the anti-detachment portion, causing the pillar to elastically deform. In this case, the first concave surface can alleviate stress concentration that occurs at the connection portion. The first concave surface is present on the first radial side, but not on the second radial side. This ensures a larger contact area between the first end face of the roller and the first wall than when the first concave surface is present throughout from the first radial side to the second radial side. Wear of the cage caused by the small contact area is suppressed.

[0013] (2) Preferably, the first concave surface has an inclined surface such that the gap formed between the first concave surface and the roller increases with increasing radial distance from the second concave surface. In this case, the cage can enhance its function of ensuring a wide contact area without impairing its function of mitigating stress concentration.

[0014] (3) Preferably, in the cage made of resin, the first wall has a connecting surface connecting the first concave surface on one of the pair of adjacent pillars to the first concave surface on the other of the pair of pillars, and the connecting surface is a surface in which the gap formed between the connecting surface and the rollers gradually increases toward the first side in the radial direction. In this case, when the cage is molded using a mold, the mold can be easily removed toward the first side in the radial direction.

[0015] (4) Preferably, the first wall is a first annular body having an annular shape, and the second wall is a second annular body. In this case, the annular cage has a plurality of pockets, and rollers are housed in each pocket.

[0016] (5) Preferably, the cage is constituted by a plurality of cage segments positioned in an annular space between an inner ring and an outer ring of a rolling bearing, and each of the cage segments has the first wall, the second wall, and two of the pillars. In this case, the cage is constituted by a plurality of cage segments.

[0017] (6) Preferably, the edge of the connecting surface on the second radial side is located on the first radial side of the ends of the first concave surface on the one pillar side and the first concave surface on the other pillar side in the second radial direction. With this configuration, the surface of the first wall with which the rollers can come into contact is widened. This makes it possible to prevent wear of the surface due to sliding contact of the rollers.

[0018] (7) A rolling bearing according to an embodiment of the present invention includes an inner ring, an outer ring, a plurality of rollers positioned between the inner ring and the outer ring, and the cage that holds the rollers. The cage of the rolling bearing reduces stress concentration that occurs when the rollers are fitted into pockets, and makes it possible to suppress wear due to contact with the rollers.

[0019] (8) A method of assembling the rolling bearing according to an embodiment of the present invention includes an integration step of assembling the roller into the pocket from at least one of the first and second radial sides to obtain a unit of the cage and the roller, and in the integration step, the roller is assembled into the pocket while pressing the anti-fall-out portion and elastically deforming the pillar.

[0020] According to the above assembly method, stress concentration that occurs when the rollers are fitted into the pockets is alleviated, and wear of the cage of the assembled rolling bearing due to contact with the rollers is suppressed.

[0021] <Details of the embodiment of the present invention> Hereinafter, an embodiment of the present invention will be described. [First embodiment of rolling bearing] Fig. 1 is a cross-sectional view showing one embodiment of a rolling bearing of the present invention. The rolling bearing 10 shown in Fig. 1 is a cylindrical roller bearing, and includes an inner ring 11, an outer ring 12, a plurality of rollers (cylindrical rollers) 13, and a cage 14 that holds the plurality of rollers 13. The inner ring 11 and the outer ring 12 have an annular shape. The rollers 13 are located between the inner ring 11 and the outer ring 12. The central axis of the inner ring 11 and the central axis of the outer ring coincide, and these central axes form a central axis C of the rolling bearing 10.

[0022] The cage 14 shown in Figure 1 is annular. For each embodiment of the present invention, a state will be described in which the central axis of the cage 14 coincides with the central axis C of the rolling bearing 10. For the inner ring 11, outer ring 12, and cage 14, the direction parallel to the central axis C is defined as the "axial direction." The direction perpendicular to the central axis C is defined as the "radial direction." The direction along a circle centered on the central axis C is defined as the "circumferential direction."

[0023] The inner ring 11 has an inner ring raceway surface 21 on its outer peripheral surface. The outer ring 12 has an outer ring raceway surface 22 on its inner peripheral surface. The outer ring 12 has flanges 23 on both axial sides of the outer ring raceway surface 22. The rollers 13 are cylindrical and have a first end face 26, a second end face 27, and an outer peripheral surface 28. The rollers 13 are in rolling contact with the inner ring raceway surface 21 and the outer ring raceway surface 22. The inner ring 11, the outer ring 12, and the rollers 13 are made of steel. The cage 14 is made of resin.

[0024] 2 is a perspective view of the cage 14. The cage 14 has a first annular body 31, a second annular body 32, and a plurality of pillars 33. The first annular body 31 is annular and forms a first wall facing the first end face 26 of the roller 13. The second annular body 32 is annular and forms a second wall facing the second end face 27 of the roller 13. The pillars 33 connect the first annular body 31 and the second annular body 32. The pillars 33 face the outer peripheral surface 28 of the roller 13. The space between a pair of pillars 33 adjacent to each other in the circumferential direction between the first annular body 31 and the second annular body 32 forms a pocket 29 that accommodates the roller 13.

[0025] The pillars 33 have inner fall-out prevention portions 34 on the inner peripheral side of the cage 14 that prevent the rollers 13 housed in the pockets 29 from falling out. The fall-out prevention portions 34 are provided partially on the pillars 33 in the axial direction and are constituted by protrusions that protrude from the pillars 33. Figure 3 is an explanatory diagram of the rollers 13 housed in the pockets 29 as viewed along the central axis P of the rollers 13. When the rollers 13 housed in the pockets 29 are displaced radially inward of the cage 14, they come into contact with the fall-out prevention portions 34, preventing the rollers 13 from falling out.

[0026] The pillars 33 have outer fall-out prevention portions 35 on the outer peripheral side of the cage 14 that prevent the rollers 13 housed in the pockets 29 from falling out. The fall-out prevention portions 35 are provided partially on the pillars 33 in the axial direction (see FIG. 2 ) and are constituted by protrusions that protrude from the pillars 33. The outer fall-out prevention portions 35 may be omitted.

[0027] The method of assembling the rolling bearing 10 shown in Figure 1 is as follows. With the cage 14 positioned on the inner periphery of the outer ring 12, the rollers 13 are fitted into the pockets 29 of the cage 14. The rollers 13 are fitted into the pockets 29 from the inner periphery of the cage 14. As shown in Figure 3, when focusing on one pocket 29, the dimension B between the two drop-out prevention portions 34 is smaller than the diameter D of the rollers 13. Therefore, when fitting the rollers 13 into the pockets 29, the rollers 13 press against the drop-out prevention portions 34, causing the posts 33 to elastically deform. The outer ring assembly is the assembly of all the rollers 13 fitted into the pockets 29 of the cage 14 positioned on the outer ring 12. The rolling bearing 10 is formed by combining the outer ring assembly with the inner ring 11.

[0028] 2 , the portion where the first annular body 31 and one of the pillars 33 are connected is a first connection portion 41. The portion where the second annular body 32 and one of the pillars 33 are connected is a second connection portion 42. When focusing on a unit pocket portion 15 that constitutes one pocket 29, two pillars 33 sandwich one roller 13 housed in that pocket 29 in the circumferential direction of the cage 14. For this reason, two first connection portions 41 exist in one pocket portion 15, and two second connection portions 42 exist in one pocket portion 15.

[0029] FIG. 4 is a diagram illustrating the rollers 13 removed from the explanatory diagram shown in FIG. 3 . FIG. 5 is an enlarged view of a portion of the cage 14. The first connecting portion 41 has a concave arc surface (second concave surface) 43 located on the outer periphery and a recess surface (first concave surface) 44 located on the inner periphery. The concave arc surface 43 is a surface shaped like a cylinder with a small radius. The recess surface 44 is a surface that is more recessed than the concave arc surface 43. The concave arc surface 43 and the recess surface 44 are also provided on the second connecting portion 42. That is, the second connecting portion 42 has a concave arc surface 43 located on the outer periphery and a recess surface 44 located on the inner periphery. In this embodiment, the concave arc surface 43 of the first connecting portion 41 and the concave arc surface 43 of the second connecting portion 42 have the same shape, and the recess surface 44 of the first connecting portion 41 and the recess surface 44 of the second connecting portion 42 have the same shape.

[0030] The recessed surface 44 is a surface shaped like a cone. The recessed surface 44 has an inclined surface 45 that increases in size as it moves away from the concave arc surface 43 in the radial direction, i.e., toward the inner periphery. The inclined surface 45 causes the gap e1 formed between the recessed surface 44 and the end face 26 (27) of the roller 13 (see FIG. 1) to increase toward the inner periphery.

[0031] FIG. 6 is a cross-sectional view of the region of the first connection portion 41 where the concave arc surface 43 is formed, as viewed in the radial direction of the cage 14. As shown in FIGS. 4 and 6 , the pillar 33 has a side surface 33a facing the outer peripheral surface 28 of the roller 13. The first annular body 31 has a side surface 31a facing the first end surface 26 of the roller 13. The concave arc surface 43 is a surface at the intersection of the first annular body 31 and the pillar 33, and is a surface whose cross section has a concave arc shape when viewed in the radial direction (see FIG. 6 ). In the cross section shown in FIG. 6 , the side surface 33a of the pillar 33 is aligned along a tangent to the first end 43a of the concave arc surface 43. The side surface 31a of the first annular body 31 is aligned along a tangent to the second end 43b of the concave arc surface 43.

[0032] FIG. 7 is a cross-sectional view of the region of the first connection portion 41 where the recess surface 44 is formed, as viewed in the radial direction of the cage 14. As shown in FIGS. 4 and 7 , the recess surface 44 is a surface at the intersection of the first annular body 31 and the pillar 33, and has a cross section that is a concave arc shape when viewed in the radial direction (see FIG. 7 ). In the cross section shown in FIG. 7 , the side surface 33 a of the pillar 33 is aligned along a tangent line at the first end 44 a of the recess surface 44. The side surface 31 a of the first annular body 31 intersects with a tangent line K at the second end 44 b of the recess surface 44. The recess surface 44 is recessed from the side surface 31 a of the first annular body 31 so as to be away from the end face 26 of the roller 13.

[0033] FIG. 8 is a perspective view showing a modified example of the cage 14 shown in FIG. 5 . FIG. 9 is a diagram for explaining the cage 14 shown in FIG. 8 , showing the pocket 29 as viewed along the central axis P of the roller 13. The same components in the cage 14 shown in FIGS. 8 and 9 and the cage 14 shown in FIGS. 2 to 5 are denoted by the same reference numerals. In the cage 14 shown in FIGS. 8 and 9 , as in the cage 14 shown in FIGS. 2 to 5 , the first connection portion 41 has a concave arc surface 43 located on the outer circumferential side and a recess surface 44 located on the inner circumferential side. The recess surface 44 is a surface that is more recessed than the concave arc surface 43. The concave arc surface 43 and the recess surface 44 are also provided in the second connection portion 42.

[0034] The cage 14 shown in FIGS. 8 and 9 differs from the cage 14 shown in FIGS. 2 to 5 in that the first annular body 31 has a connecting surface 46. In the case of the cage 14 shown in FIGS. 8 and 9 , the first annular body 31 has a connecting surface 46 connecting the recess surface 44 on one of a pair of circumferentially adjacent columns 33 to the recess surface 44 on the other of the columns 33. The connecting surface 46 is a surface on which the gap e2 formed between the rollers 13 (first end surfaces 26) gradually increases toward the inner periphery. The connecting surface 46 is a surface that slopes from the side surface 31 a of the first annular body 31. Note that the second annular body 32 may have a connecting surface 46, similar to the first annular body 31. When the cage 14 is molded using a mold (injection molding mold), the connecting surface 46 makes it easy to remove the mold in the radial direction.

[0035] 16 and 17 are diagrams showing modified examples of the cage 14 shown in FIGS. 8 and 9. The configuration shown in FIGS. 16 and 17 differs from the configuration shown in FIGS. 8 and 9 in the coupling surface 46, but the other configurations are the same. The same components are denoted by the same reference numerals, and a description of the same components will be omitted. In the modified example shown in FIGS. 16 and 17, compared to the configuration shown in FIGS. 8 and 9, the radially outer edge 46e of the coupling surface 46 is positioned closer to the radially inner side. The edge 46e is a portion along the line where the coupling surface 46 and the side surface 31a intersect.

[0036] Specifically, the edge 46e of the connecting surface 46 is located radially inward of the radially outer ends 44e of the recessed surface 44 on one pillar 33 side and the recessed surface 44 on the other pillar 33 side. With this configuration, the area of ​​the side surface 31a of the first annular body 31 with which the roller 13 can come into contact is larger than in the configurations shown in Figures 8 and 9. As a result, it is possible to reduce wear on the side surface 31a.

[0037] 8 and 9 and the embodiments shown in Figures 16 and 17, when the roller 13 is fitted into the pocket 29, the intersection 25 (see Figure 18) between the end face 26 and the outer circumferential surface 28 of the roller 13 comes into contact with the connecting surface 46. This makes it easy to fit the roller 13 into the pocket 29. The intersection 25 is a convexly curved portion.

[0038] FIG. 19 is a diagram showing yet another modified example of the cage 14. In the configuration shown in FIG. 17 , the edge 46 e of the connecting surface 46 has a linear shape. In contrast, in the configuration shown in FIG. 19 , the edge 46 e of the connecting surface 46 has an arc shape. The arc shape is a shape that follows a circle that is concentric with the arc shape of the inner circumferential surface 31 b of the first annular body 31. The configuration shown in FIG. 17 is more effective in increasing the area of ​​the side surface 31 a. The configuration shown in FIG. 19 is more effective in facilitating the insertion of the rollers 13 into the pockets 29. The arc shape of the edge 46 e may be an arc shape that does not follow a circle that is concentric with the arc shape of the inner circumferential surface 31 b of the first annular body 31.

[0039] 18 , the coupling surface 46 intersects with the inner peripheral surface 31 b of the first annular body 31. The line of intersection is the radially inner edge 46 f of the coupling surface 46. In the embodiment shown in FIG. 18 , the inner edge 46 f of the coupling surface 46 coincides with the radially inner end 44 f of the recess surface 44. However, the inner edge 46 f of the coupling surface 46 may be located closer to the rollers 13 in the axial direction than the inner end 44 f of the recess surface 44. In each of the above embodiments of the cage 14, the second annular body 32 also has a configuration similar to the coupling surface 46 of the first annular body 31.

[0040] [Second embodiment of rolling bearing] Figure 10 is a cross-sectional view showing another embodiment of a rolling bearing. The rolling bearing 10 shown in Figure 10 is a tapered roller bearing, and the rollers 13 provided between the inner ring 11 and the outer ring 12 are tapered rollers. In the rolling bearing 10 shown in Figure 10, the same components as those in the rolling bearing 10 shown in Figure 1 are given the same reference numerals, and a description of these components will be omitted.

[0041] Figure 11 is a perspective view of the cage 14 of the rolling bearing 10 shown in Figure 10. The cage 14 has a large-diameter first annular body 31, a small-diameter second annular body 32, and a plurality of pillars 33. The first annular body 31 is annular and forms a first wall facing the first end face 26 of the roller 13. The second annular body 32 is annular and forms a second wall facing the second end face 27 of the roller 13. The pillars 33 connect the first annular body 31 and the second annular body 32. The pillars 33 face the outer peripheral surface 28 of the roller 13. The space between a pair of pillars 33 adjacent in the circumferential direction between the first annular body 31 and the second annular body 32 forms a pocket 29 that accommodates the roller 13.

[0042] The pillars 33 have inner drop-out prevention portions 34 on the inner peripheral side of the cage 14 that prevent the rollers 13 housed in the pockets 29 from falling out. The drop-out prevention portions 34 are provided partially in the axial direction on the pillars 33 and are constituted by protrusions that protrude from the pillars 33. In the embodiment shown in Figure 11, the drop-out prevention portions 34 are provided in a position closer to the first annular body 31 than to the second annular body 32. When the rollers 13 housed in the pockets 29 are displaced radially inward of the cage 14, they come into contact with the drop-out prevention portions 34, preventing the rollers 13 from falling out.

[0043] The method of assembling the rolling bearing 10 shown in Figure 10 is as follows. With the cage 14 positioned on the inner periphery of the outer ring 12, the rollers 13 are inserted into the pockets 29 of the cage 14. The rollers 13 are inserted into the pockets 29 from the inner periphery of the cage 14. As with the first embodiment (see Figure 3), when focusing on one pocket 29, the dimension between the two drop-out prevention portions 34 is smaller than the diameter of the roller 13 at the position where these drop-out prevention portions 34 are formed. Therefore, when inserting the rollers 13 into the pockets 29, the rollers 13 press against the drop-out prevention portions 34, causing the posts 33 to elastically deform. The outer ring assembly is formed when all of the rollers 13 are inserted into the pockets 29 of the cage 14 positioned on the outer ring 12. The rolling bearing 10 is formed when the outer ring assembly is combined with the inner ring 11. When the rollers 13 are inserted, they can be smoothly inserted into the pockets 29 by using an insertion jig to push the end faces of the rollers 13 along the first concave surfaces 44 .

[0044] 11, the portion where the first annular body 31 and one of the pillars 33 are connected is a first connection portion 41. The portion where the second annular body 32 and one of the pillars 33 are connected is a second connection portion 42. In one pocket portion 15 that constitutes one pocket 29, there are two first connection portions 41 and two second connection portions 42. This is also the same as in the first embodiment (see FIG. 2).

[0045] The first connecting portion 41 has a concave arc surface 43 located on the outer periphery side and a recessed surface 44 located on the inner periphery side. The concave arc surface 43 is a surface shaped like a cylinder with a small radius. The recessed surface 44 is a surface that is more recessed than the concave arc surface 43. In the embodiment shown in FIG. 11 , the concave arc surface 43 and the recessed surface 44 are not provided in the second connecting portion 42, but they may be provided in the second connecting portion 42.

[0046] The recessed surface 44 is a surface shaped like a cone. The recessed surface 44 has an inclined surface 45 that increases in size as it moves away from the concave arc surface 43 in the radial direction, i.e., toward the inner periphery. The inclined surface 45 causes the gap e1 formed between the recessed surface 44 and the end face 26 of the roller 13 (see FIG. 10) to increase toward the inner periphery. The shapes of the concave arc surface 43 and the recessed surface 44 are the same as those of the first embodiment (FIGS. 6 and 7).

[0047] FIG. 12 is a perspective view showing a modified example of the cage 14 shown in FIG. 11 . The cage 14 shown in FIG. 12 differs from the cage 14 shown in FIG. 11 in that the first annular body 31 has a connecting surface 46. In the case of the cage 14 shown in FIG. 12 , the first annular body 31 has a connecting surface 46 that connects the recess surface 44 on one of a pair of circumferentially adjacent columns 33 to the recess surface 44 on the other column 33. The connecting surface 46 is a surface in which the gap formed between the rollers 13 (first end surfaces 26) gradually increases toward the inner periphery. The connecting surface 46 is a surface that slopes from the side surface 31 a of the first annular body 31. The connecting surface 46 has the same configuration as the connecting surface 46 of the cage 14 shown in FIG. 8 .

[0048] Figure 20 is a diagram showing yet another modified example of the cage 14 shown in Figures 11 and 12. The embodiment shown in Figure 20 differs from the embodiments shown in Figures 11 and 12 in the coupling surface 46, but the other configurations are the same. The same components are given the same reference numerals, and a description of the same components will be omitted. In the modified example shown in Figure 20, compared to the embodiment shown in Figure 12, the radially outer edge 46e of the coupling surface 46 is positioned closer to the radially inner side. The edge 46e is a portion along a line intersecting the coupling surface 46 and the side surface 31a.

[0049] Specifically, the edge 46e of the connecting surface 46 is located radially inward of the radially outer ends 44e of the recessed surface 44 on one pillar 33 side and the recessed surface 44 on the other pillar 33 side. With this configuration, the area of ​​the side surface 31a of the first annular body 31 with which the rollers 13 can come into contact is larger than in the configuration shown in FIG. 12 . As a result, it is possible to reduce wear of the side surface 31a. The edge 46e of the connecting surface 46 may be linear, or may be arc-shaped as described in the configuration shown in FIG. 19 . In each of the above configurations of the cage 14, the second annular body 32 also has a configuration similar to the connecting surface 46 of the first annular body 31.

[0050] [Third embodiment of rolling bearing] Figure 13 is a cross-sectional view showing another embodiment of a rolling bearing. The rolling bearing 10 shown in Figure 13 is a tapered roller bearing, and the rollers 13 provided between the inner ring 11 and the outer ring 12 are tapered rollers. With regard to the rolling bearing 10 shown in Figure 13, the same components as those in the rolling bearing 10 shown in Figure 1 are given the same reference numerals, and description of these same components will be omitted. As shown in Figure 14, the cage 14 of the rolling bearing 10 according to the third embodiment is made up of a plurality of cage segments 17. The plurality of cage segments 17 are located in the annular space S between the inner ring 11 and the outer ring 12. One roller 13 is held in one cage segment 17.

[0051] Figure 15 is a perspective view of the cage segment 17. The cage segment 17 has a first wall 51, a second wall 52, and two pillars 53. The first wall 51 faces the first end face 26 of the roller 13 (see Figure 13). The second wall 52 faces the second end face 27 of the roller 13. The pillars 53 connect the first wall 51 and the second wall 52. The pillars 53 face the outer peripheral surface 28 of the roller 13. The space between the first wall 51 and the second wall 52 and between the pair of pillars 53 forms the pocket 29 that accommodates the roller 13.

[0052] The pillars 53 have outer drop-out prevention portions 35 on the outer peripheral side of the cage segment 17 that prevent the rollers 13 housed in the pockets 29 from falling out. The drop-out prevention portions 35 are configured by protrusions that protrude from the pillars 53. When the rollers 13 housed in the pockets 29 are displaced radially outward of the cage 14, they come into contact with the drop-out prevention portions 35, preventing the rollers 13 from falling out. The pillars 53 have inner drop-out prevention portions 34 on the inner peripheral side of the cage segment 17 that prevent the rollers 13 housed in the pockets 29 from falling out. The drop-out prevention portions 34 are configured by protrusions that protrude from the pillars 53. When the rollers 13 housed in the pockets 29 are displaced radially inward of the cage 14, they come into contact with the drop-out prevention portions 34, preventing the rollers 13 from falling out.

[0053] The method of assembling the rolling bearing 10 shown in Figure 13 is as follows. The rollers 13 are fitted into the pockets 29 of the cage segments 17. The rollers 13 are fitted into the pockets 29 from the outer periphery of the cage segment 17. Focusing on one cage segment 17 (see Figure 15), the dimension between the two outer fall-out prevention portions 35 is smaller than the diameter of the rollers 13 at the positions where these fall-out prevention portions 35 are formed. For this reason, when fitting the rollers 13 into the pockets 29, the rollers 13 press on the outer fall-out prevention portions 35, causing the posts 53 to elastically deform. A roller and cage assembly is formed when all rollers 13 are fitted into the cage segment 17. A combination of a roller and cage assembly with an inner ring 11 and an outer ring 12 constitutes the rolling bearing 10.

[0054] 15 , the portion where the first wall 51 and one of the pillars 53 are connected is the first connection portion 41. The portion where the second wall 52 and one of the pillars 53 are connected is the second connection portion 42. Two first connection portions 41 exist in one cage segment 17, and two second connection portions 42 exist in one cage segment 17.

[0055] The first connecting portion 41 has a concave arc surface 43 located on the inner periphery side and a recessed surface 44 located on the outer periphery side. The concave arc surface 43 is a surface shaped like a cylinder with a small radius. The recessed surface 44 is a surface that is more recessed than the concave arc surface 43. The concave arc surface 43 and the recessed surface 44 are also provided on the second connecting portion 42. That is, the second connecting portion 42 has a concave arc surface 43 located on the inner periphery side and a recessed surface 44 located on the outer periphery side. The concave arc surface 43 of the first connecting portion 41 and the concave arc surface 43 of the second connecting portion 42 have the same shape, and the recessed surface 44 of the first connecting portion 41 and the recessed surface 44 of the second connecting portion 42 have the same shape.

[0056] The recessed surface 44 is a surface shaped like a cone. The recessed surface 44 has an inclined surface 45 that increases in size as it moves away from the concave arc surface 43 in the radial direction, i.e., toward the outer periphery. The inclined surface 45 causes the gap formed between the recessed surface 44 and the end surface 26 (27) of the roller 13 (see FIG. 13) to increase in size as it moves toward the outer periphery. The shapes of the concave arc surface 43 and the recessed surface 44 are the same as those of the first embodiment (FIGS. 6 and 7).

[0057] [Regarding the rolling bearing 10 and cage 14 of each embodiment] As described above, the cage 14 of the rolling bearing 10 of each embodiment has a first annular body 31 (first wall 51) facing the first end face 26 of the roller 13, a second annular body 32 (second wall 52) facing the second end face 27 of the roller 13, and a plurality of pillars 33 (pillars 53) connecting the first annular body 31 (first wall 51) and the second annular body 32 (second wall 52). The space between the first annular body 31 (first wall 51) and the second annular body 32 (second wall 52) and between the pair of pillars 33 (pillars 53) forms the pocket 29 that accommodates the rollers 13.

[0058] The pillars 33 (pillars 53) have anti-fall-out portions on a first radial side that prevent the rollers 13 accommodated in the pockets 29 from falling out. In the case of the cage 14 of the first embodiment (see FIGS. 3 and 4) and the case of the cage 14 of the second embodiment (see FIG. 11), the first radial side is the inner peripheral side of the cage 14, and the second radial side is the outer peripheral side of the cage 14. In the case of the cage 14 (retainer segment 17) of the third embodiment (see FIG. 15), the first radial side is the outer peripheral side of the cage 14 (retainer segment 17), and the second radial side is the inner peripheral side of the cage 14 (retainer segment 17).

[0059] In each of the above-described embodiments of the cage 14, the first connection portion 41 between the first annular body 31 (first wall 51) and the pillar 33 (pillar 53) has a concave arc surface 43 located on the second radial side and a recess surface 44 located on the first radial side. The recess surface 44 is recessed more deeply than the concave arc surface. A method for assembling a rolling bearing 10 having the above-described embodiments of the cage 14 includes an integration step of fitting the rollers 13 into the pockets 29 from the first radial side to obtain a unit consisting of the cage 14 and the rollers 13. In the integration step, the rollers 13 press the anti-detachment portions to elastically deform the pillars 33 (pillars 53), and the rollers 13 are fitted into the pockets 29.

[0060] To fit the rollers 13 into the pockets 29, the pillars 33 (pillars 53) elastically deform. Even in this case, the cage 14 can alleviate stress concentration that occurs at the first connection portion 41 by using the recessed surface 44. The recessed surface 44 exists on the first radial side, but does not exist on the second radial side. This ensures a larger contact area between the first end faces 26 of the rollers 13 and the first annular body 31 (first wall 51) than in the past. The reduction in contact area reduces wear on the cage 14.

[0061] The recessed surface 44 is present on the first radial side but not on the second radial side, thereby preventing a decrease in the strength of the cage 14. In each of the above-described embodiments of the cage 14, the recessed surface 44 increases the length of the elastically deforming portion of the pillar 33 (pillar 53), making it easier to fit the rollers 13 into the pockets 29.

[0062] In the first and third embodiments, the second connection portion 42 between the second annular body 32 (second wall 52) and the pillar 33 (pillar 53) has, similar to the first connection portion 41, a concave arc surface 43 located on the second radial side and a recess surface 44 located on the first radial side. The recess surface 44 is recessed more than the concave arc surface 43. Therefore, a larger contact area is ensured between the second end surface 27 of the roller 13 and the second annular body 32 (second wall 52) than in the past.

[0063] In each of the above embodiments, recess surface 44 has an inclined surface 45 that increases the gap formed between recess surface 44 and roller 13 as it moves away from concave arc surface 43 in the radial direction. This inclined surface 45 ensures a wide contact area between first end surface 26 of roller 13 and first annular body 31 (first wall 51) without impairing the stress concentration relief function.

[0064] [Others] In the above embodiments, the recess surface (first concave surface) 44 connected to the concave arc surface (second concave surface) 43 has a conical shape. However, the recess surface 44 may have a shape other than that. Although not shown, the recess surface 44 may have a surface shaped like a cylinder larger than the concave arc surface 43. For example, the recess surface 44 may be composed of a surface shaped like a cylinder larger than the concave arc surface 43 and a surface shaped like a cone.

[0065] In each of the above embodiments, the boundary between the concave arc surface 43 and the recess surface 44 is located at a radially intermediate position of the first connection portion 41 (second connection portion 42). The concave arc surface 43 may be formed over a longer radial range than the recess surface 44, or the recess surface 44 may be formed over a longer radial range than the concave arc surface 43. When the concave arc surface 43 is formed over a longer range, the contact area becomes wider. When the recess surface 44 is formed over a longer range, the stress concentration relief function is enhanced.

[0066] As explained in each of the above embodiments, the shape of the cage may differ depending on the type of rolling bearing, that is, depending on the rolling elements that the rolling bearing has.

[0067] The above-described embodiments are illustrative in all respects and are not limiting. The scope of the present invention is defined by the claims rather than the above-described embodiments, and includes all modifications within the scope equivalent to the configurations described in the claims.

[0068] 10 Rolling bearing 11 Inner ring 12 Outer ring 13 Roller 14 Cage 17 Cage segment 26 First end face 27 Second end face 29 Pocket 31 First annular body (first wall) 32 Second annular body (second wall) 33 Pillar 34 Fall-off prevention portion 35 Fall-off prevention portion 41 First connecting portion (connecting portion) 42 Second connecting portion 43 Concave arc surface (second concave surface) 44 Recess surface (first concave surface) 44e End 45 Inclined surface 46 Connecting surface 46e End edge 51 First wall 52 Second wall 53 Pillar

Claims

1. A cage having a first wall facing a first end face of a roller of a rolling bearing, a second wall facing a second end face of the roller, and a plurality of columns connecting the first wall and the second wall, wherein a space between the first wall and the second wall and between a pair of the columns serves as a pocket for accommodating the roller, wherein at least one of a first side and a second side in the radial direction of the column has a dropout prevention portion for preventing dropout of the roller accommodated in the pocket, a connection portion between the first wall and the column has a first concave surface located on a first side in the radial direction and a second concave surface located on a second side in the radial direction, and the first concave surface is more recessed than the second concave surface, the first concave surface has an inclined surface such that a gap formed between the first concave surface and the roller increases as the first concave surface moves radially away from the second concave surface, the first wall has a connecting surface connecting the first concave surface on one column side and the first concave surface on the other column side among a pair of adjacent columns, the connecting surface is a surface on which a gap formed between the connecting surface and the roller gradually increases toward a first side in the radial direction, and the cage is made of resin.

2. the first wall is a first annular body that is annular, the second wall is a second annular body that is annular, and the cage according to claim 1.

3. A cage constituted by a plurality of cage segments located in an annular space between an inner ring and an outer ring of a rolling bearing, each of the cage segments having the first wall, the second wall, and two of the columns, and the cage according to claim 1.

4. an edge on a second side in the radial direction of the connecting surface is located on a first side in the radial direction rather than an end on a second side in the radial direction of the first concave surface on one column side and the first concave surface on the other column side, and the cage according to claim 1.

5. An inner ring, an outer ring, a plurality of rolling elements positioned between the inner ring and the outer ring, and a cage for holding the rolling elements. The cage is the cage according to any one of claims 1 to 4. Rolling bearing.

6. A method for assembling the rolling bearing according to claim 5, having an integration step of incorporating the rolling element into the pocket from at least one of a first side and a second side in the radial direction to obtain a unit of the cage and the rolling element, In the integration step, the rolling element is incorporated into the pocket while pushing the anti-drop portion and elastically deforming the column. A method for assembling a rolling bearing.