Retainer and method of manufacturing the same

Abstract

To provide a retainer capable of suppressing breakage.SOLUTION: A retainer includes a first plate member, a second plate member, and a connection member 53. The first plate member includes a plurality of first pocket forming portions, and a first connection portion 512 positioned between a pair of first pocket forming portions adjacent with each other. The second plate member includes a plurality of second pocket forming portions, and a second connection portion 522 positioned between a pair of second pocket forming portions adjacent with each other. A shaft portion 531 of the connection member 53 is press-fitted in a first through hole 51c of the first connection portion 512, and is inserted into a second through hole 52c of the second connection portion 522. A bearing surface of a head portion 532 is brought into contact with a main surface 51a of the first connection portion 512. A space exists between a region of the first connection portion 512 connecting an inner side surface of the first through hole 51 and a main surface 51a and a region of the connection member 53 connecting an outer side surface 53c of the shaft portion 531 and the bearing surface of the head portion 532.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a cage and a method for manufacturing the cage. [Background technology]

[0002] A cage for holding a plurality of rolling elements is known (see, for example, Patent Document 1). The cage described in Patent Document 1 includes a first plate member and a second plate member that are arranged to face each other in the axial direction, thereby forming a plurality of pocket forming portions. The first plate member and the second plate member are connected by a connecting member that includes a shaft portion and a head portion formed on one end of the shaft portion. The shaft portion of the connecting member is inserted into a first through hole formed in the first plate member and a second through hole formed in the second plate member, with the head portion positioned on the opposite side of the first plate member from the second plate member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-173310 Summary of the Invention [Problem to be solved by the invention]

[0004] In the cage described above, the shaft portion of the connecting member may be press-fitted into the first through hole of the first plate member. When the shaft portion of the connecting member is press-fitted into the first through hole, a portion of the inner wall of the first through hole may undergo plastic deformation, resulting in the shaft portion moving from inside the first through hole onto the main surface of the first plate member opposite the second plate member so as to protrude from the main surface. In this case, the protruding portion protruding from the main surface may be compressed by the head of the connecting member, which may cause stress concentration in the protruding portion, and the first plate member may be damaged due to the stress concentration.

[0005] An object of the present invention is to provide a cage that can suppress breakage. [Means for solving the problem]

[0006] The cage of the present invention is [1] "a cage for rollably holding a plurality of rolling elements lined up along a circumferential direction, the cage comprising: a first plate member having an annular shape when viewed in an axial direction; a second plate member having an annular shape when viewed in the axial direction and facing the first plate member in the axial direction; and a connecting member connecting the first plate member and the second plate member, wherein the first plate member includes a plurality of first pocket forming portions lined up along the circumferential direction and a first connecting portion located between a pair of adjacent first pocket forming portions of the plurality of first pocket forming portions; the second plate member includes a plurality of second pocket forming portions lined up along the circumferential direction and facing the plurality of first pocket forming portions in the axial direction; and a second connecting portion located between a pair of adjacent second pocket forming portions of the plurality of second pocket forming portions and facing the first connecting portion in the axial direction; a retainer in which the first through hole and the plurality of second pocket forming portions define a plurality of pockets for holding the plurality of rolling elements, the first connecting portion has a first through hole formed therein, the second connecting portion has a second through hole formed therein, the connecting member includes a shaft portion and a head portion formed at one end of the shaft portion, the shaft portion of the connecting member is press-fitted into the first through hole and inserted into the second through hole with the head portion positioned on the opposite side of the first connecting portion to the second connecting portion, a seating surface of the head portion facing the first connecting portion abuts against a main surface of the first connecting portion on the opposite side to the second connecting portion, and at least one of a first region of the first connecting portion connecting an inner side surface of the first through hole and the main surface and a second region of the connecting member connecting an outer side surface of the shaft portion and the seating surface of the head portion is recessed, and a space exists between the first region and the second region.

[0007] In the cage described in [1] above, the shank of the connecting member is press-fitted into the first through hole and inserted into the second through hole with its head positioned on the opposite side of the first connecting portion from the second connecting portion. This effectively connects the first plate member and the second plate member. Furthermore, at least one of the first region of the first connecting portion and the second region of the connecting member is recessed, and a space exists between the first region and the second region. Even if a portion of the inner wall of the first through hole undergoes plastic deformation and moves toward the main surface of the first connecting portion opposite the second connecting portion due to the press-fitting of the shank of the connecting member into the first through hole, the moved portion remains in the space, preventing the moved portion from being compressed by the connecting member. As a result, damage to the first plate member due to stress concentration is suppressed. Therefore, this cage can suppress damage to the first plate member.

[0008] The cage of the present invention may be [2] "the cage according to the above [1], wherein the first region is a chamfer provided on the first through hole." This makes it possible to easily form the space.

[0009] The method of manufacturing a cage of the present invention is [3] "A method of manufacturing a cage for rollably holding a plurality of rolling elements arranged along a circumferential direction, the method comprising: a first plate member having an annular shape including a plurality of first pocket forming portions arranged along the circumferential direction and a first connecting portion located between a pair of adjacent first pocket forming portions of the plurality of first pocket forming portions; a second plate member having an annular shape including a plurality of second pocket forming portions arranged along the circumferential direction and a second connecting portion located between a pair of adjacent second pocket forming portions of the plurality of second pocket forming portions; a first step of preparing a plate member and a connecting member for connecting the first plate member and the second plate member; and a second step of connecting the first plate member and the second plate member by the connecting member, wherein the first connecting portion of the first plate member prepared in the first step has a first through hole formed therein, and the second connecting portion of the second plate member prepared in the first step has a second through hole formed therein, the connecting member prepared in the first step includes a shaft portion and a head portion formed at one end of the shaft portion, and in the second step, the connecting member is The shaft portion is press-fitted into the first through-hole so that, with the head positioned on the opposite side of the second connecting portion to the first connecting portion, a seat surface of the head that faces the first connecting portion abuts on a main surface of the first connecting portion that is on the opposite side of the second connecting portion to the second connecting portion, and thereafter, the plurality of second pocket forming portions and the plurality of first pocket forming portions face each other in the axial direction, the second connecting portion and the first connecting portion face each other in the axial direction, and the plurality of second pocket forming portions and the plurality of first pocket forming portions are disposed between the plurality of second pocket forming portions and the plurality of first pocket forming portions. a method for manufacturing a cage, wherein the first connecting portion of the first plate member prepared in the first step is inserted into the second through hole so as to form a plurality of pockets for holding rolling elements, and a first region connecting the inner surface of the first through hole and the main surface is recessed with respect to a first intersection line between an extension of the inner surface and an extension of the main surface, or a second region of the connecting member prepared in the first step connecting the outer surface of the shaft portion and the seating surface of the head is recessed with respect to a first intersection line between an extension of the outer surface and an extension of the seating surface.

[0010] In the second step of the cage manufacturing method described in [3] above, the shank of the connecting member is press-fitted into the first through hole and inserted into the second through hole with the head positioned on the opposite side of the first connecting portion from the second connecting portion. This effectively connects the first plate member and the second plate member. Furthermore, the first region of the first connecting portion of the first plate member prepared in the first step is recessed relative to the first intersection line, or the second region of the connecting member prepared in the first step is recessed relative to the second intersection line. This prevents the moved portion from being compressed by the connecting member, even if a portion of the inner wall of the first through hole is plastically deformed and moves toward the main surface of the first connecting portion opposite the second connecting portion due to the press-fitting of the shank of the connecting member into the first through hole. As a result, damage to the first plate member due to stress concentration is suppressed. Therefore, this cage manufacturing method can suppress damage to the first plate member.

[0011] The method for manufacturing a cage of the present invention may be [4] "the method for manufacturing a cage according to the above [3], wherein the first region of the first plate member prepared in the first step is a chamfer applied to the first through hole." This makes it possible to easily form the first region.

[0012] The method for manufacturing a cage of the present invention may be [5] "the method for manufacturing a cage according to the above [3] or [4], wherein, in the first plate member prepared in the first step, the volume of a space defined by the extended surface of the inner side surface of the first through hole, the extended surface of the main surface, and the first region is larger than the volume of an inner wall portion of the first plate member overlapping with the shaft portion when viewed from the axial direction of the first through hole in a state in which the axis of the first through hole of the first plate member prepared in the first step and the axis of the shaft portion of the connecting member prepared in the first step are overlapped." In this way, even if a part of the inner wall portion of the first through hole moves toward the main surface of the first connecting portion on the opposite side from the second connecting portion while plastically deforming due to press-fitting of the shaft portion of the connecting member into the first through hole, the moved part remains reliably in the space, and as a result, the moved part is reliably prevented from being compressed by the connecting member. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a cage that can suppress breakage. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a front view of a rolling bearing according to an embodiment. [Figure 2] FIG. 2 is a perspective view of the cage shown in FIG. 1. [Figure 3] FIG. 3 is a partial cross-sectional view of the cage shown in FIG. 2. [Figure 4] FIG. 4 is an enlarged view of a portion IV-IV of FIG. 3. [Figure 5] 3 is a flowchart showing steps of a method for manufacturing the cage shown in FIG. 2. [Figure 6] 10 is a partial cross-sectional view of the first plate member before the connecting member is press-fitted into the first through-hole. FIG. [Figure 7] 10 is a view showing the first plate member and the connecting member before the connecting member is press-fitted into the first through hole. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each drawing, the same or corresponding parts are designated by the same reference numerals, and duplicated explanations will be omitted.

[0016] As shown in Figure 1, rolling bearing 1 comprises an inner ring 2, an outer ring 3, multiple rolling elements 4, and a cage 5. Hereinafter, the direction parallel to the center line A of rolling bearing 1 will be referred to as the axial direction, the direction perpendicular to center line A will be referred to as the radial direction, and the direction along the circumference centered on center line A when viewed from a direction parallel to center line A will be referred to as the circumferential direction.

[0017] The inner ring 2 has a raceway surface 2a. The raceway surface 2a faces outward in the radial direction and extends annularly in the circumferential direction. As an example, the inner surface of the inner ring 2 in the radial direction is fitted onto a shaft (not shown).

[0018] The outer ring 3 is disposed radially outward of the inner ring 2. The outer ring 3 has a raceway surface 3a. The raceway surface 3a faces radially inward and extends annularly in the circumferential direction. As an example, the radially outer surface of the outer ring 3 is fitted into a housing (not shown).

[0019] The plurality of rolling elements 4 are arranged in a line along the circumferential direction between the inner ring 2 and the outer ring 3. More specifically, the plurality of rolling elements 4 are arranged between the raceway surface 2a of the inner ring 2 and the raceway surface 3a of the outer ring 3. In this embodiment, each rolling element 4 is a ball (spherical body).

[0020] The cage 5 is used to hold the plurality of rolling elements 4. More specifically, the cage 5 holds the plurality of rolling elements 4 so that each rolling element 4 can roll freely between the raceway surface 2 a of the inner ring 2 and the raceway surface 3 a of the outer ring 3.

[0021] As shown in FIG. 2, the cage 5 is a wave-shaped cage. The cage 5 includes a first plate member 51, a second plate member 52, and a plurality of connecting members 53. The first plate member 51 and the second plate member 52 each have an annular shape when viewed in the axial direction. The first plate member 51 and the second plate member 52 face each other in the axial direction. The center lines of the first plate member 51 and the second plate member 52 overlap with the center line A of the rolling bearing 1 (see FIG. 1). The first plate member 51 and the second plate member 52 define a plurality of pockets 5a between them.

[0022] The first plate member 51 is formed by, for example, press molding. The first plate member 51 includes a plurality of first pocket forming portions 511 and a plurality of first connecting portions 512. The first pocket forming portions 511 and the first connecting portions 512 are each a partial region of the first plate member 51 that is integrally formed from the same material. The plurality of first pocket forming portions 511 are lined up along the circumferential direction. The first pocket forming portions 511 are curved toward one side in the axial direction. The first pocket forming portions 511 include a concave surface that is recessed toward one side in the axial direction.

[0023] The first connecting portion 512 is located between a pair of adjacent first pocket forming portions 511. The first connecting portion 512 is connected to the pair of first pocket forming portions 511. The first connecting portion 512 is formed flat along a plane intersecting the axial direction. The first pocket forming portions 511 are formed so as to be recessed in the axial direction relative to the first connecting portion 512. The first plate member 51 is, for example, a cold-rolled steel plate (SPCC) or the like.

[0024] The second plate member 52 has the same structure as the first plate member 51. The second plate member 52 is formed, for example, by press molding. The second plate member 52 includes a plurality of second pocket forming portions 521 and a plurality of second connecting portions 522. The second pocket forming portions 521 and the second connecting portions 522 are each a partial region of the second plate member 52 integrally formed from the same material. The plurality of second pocket forming portions 521 are lined up along the circumferential direction. The second pocket forming portions 521 are curved toward the other side in the axial direction. The second pocket forming portions 521 include a concave surface that is recessed toward the other side in the axial direction.

[0025] The second connecting portion 522 is located between a pair of adjacent second pocket forming portions 521. The second connecting portion 522 is connected to the pair of second pocket forming portions 521. The second connecting portion 522 is formed flat along a plane intersecting the axial direction. The second pocket forming portions 521 are formed so as to be recessed in the axial direction relative to the second connecting portion 522. The second plate member 52 is, for example, a cold-rolled steel plate (SPCC) or the like.

[0026] The plurality of first pocket forming portions 511 and the plurality of second pocket forming portions 521 face each other in the axial direction. As a result, the facing first pocket forming portions 511 and second pocket forming portions 521 define pockets 5a in which rolling elements 4 are held. The pockets 5a are formed by the concave surfaces of the first pocket forming portions 511 and the second pocket forming portions 521. The plurality of first connecting portions 512 and the plurality of second connecting portions 522 face each other in the axial direction. The first connecting portions 512 and the second connecting portions 522 are in contact with each other.

[0027] The connecting member 53 connects the first plate member 51 and the second plate member 52. Specifically, the connecting member 53 connects the first connecting portion 512 of the first plate member 51 and the second connecting portion 522 of the second plate member 52. The connecting member 53 is a so-called rivet. The connecting member 53 is less susceptible to plastic deformation than the first plate member 51. The yield point (upper yield point or lower yield point) of the connecting member 53 is higher than the yield point of the first plate member 51. The connecting member 53 is made of a material such as carbon steel (S10C), for example.

[0028] FIG. 3 is a cross-sectional view of the first connecting portion 512 of the first plate member 51, the second connecting portion 522 of the second plate member 52, and the connecting member 53. As shown in FIG. 3, the first connecting portion 512 includes a main surface 51a and a main surface 51b. The main surface 51a and the main surface 51b are each flat surfaces that intersect in the axial direction. The main surface 51a is the surface of the first connecting portion 512 that faces away from the second connecting portion 522. The main surface 51b is the surface of the first connecting portion 512 that faces the second connecting portion 522. In other words, the main surface 51b faces away from the main surface 51a.

[0029] A first through hole 51c is formed in the first connecting portion 512. The first through hole 51c penetrates the first connecting portion 512. The first through hole 51c opens to both the main surface 51a and the main surface 51b. The first through hole 51c has, for example, a circular shape when viewed in the axial direction.

[0030] The second connecting portion 522 includes a principal surface 52a and a principal surface 52b. The principal surface 52a and the principal surface 52b are flat surfaces that intersect in the axial direction. The principal surface 52a is a surface of the second connecting portion 522 that faces away from the first connecting portion 512. The principal surface 52b is a surface of the second connecting portion 522 that faces the first connecting portion 512. In other words, the principal surface 52b faces away from the principal surface 52a. The principal surface 52b faces the principal surface 51b of the first connecting portion 512 and is in contact with the principal surface 51b.

[0031] A second through hole 52c is formed in the second connecting portion 522. The second through hole 52c penetrates the second connecting portion 522. The second through hole 52c opens to both the main surface 52a and the main surface 52b. The second through hole 52c has, for example, a circular shape when viewed in the axial direction. The axis of the second through hole 52c coincides with the axis of the first through hole 51c. The diameter of the second through hole 52c is the same as the diameter of the first through hole 51c.

[0032] The connecting member 53 includes a shaft portion 531, a head portion 532, and a bottom portion 533. The shaft portion 531 has, for example, a cylindrical shape. The shaft portion 531 is located inside the first through hole 51c and the second through hole 52c. The head portion 532 is formed at one end of the shaft portion 531. The head portion 532 is located on the opposite side of the first connecting portion 512 from the second connecting portion 522. When viewed from the axial direction, the outer edge of the head portion 532 is located outside the outer edge of the shaft portion 531. When viewed from the axial direction, the head portion 532 has, for example, a circular shape. The diameter of the head portion 532 is larger than the diameter of the shaft portion 531.

[0033] The bottom portion 533 is formed at the other end of the shaft portion 531. The bottom portion 533 is located on the opposite side of the first connecting portion 512 with respect to the second connecting portion 522. When viewed from the axial direction, the outer edge of the bottom portion 533 is located outward from the outer edge of the shaft portion 531. When viewed from the axial direction, the bottom portion 533 has, for example, a circular shape. The diameter of the bottom portion 533 is larger than the diameter of the shaft portion 531. The bottom portion 533 is formed, for example, by crimping the other end of the shaft portion 531.

[0034] The shaft portion 531 is press-fitted into the first through hole 51c and inserted into the second through hole 52c to facilitate assembly of the connecting member 53 to the first plate member 51 and the second plate member 52. Specifically, the shaft portion 531 includes a press-fit region 53a and an insertion region 53b. The press-fit region 53a is located on the opposite side of the insertion region 53b from the bottom portion 533. The press-fit region 53a is connected to the head portion 532. The press-fit region 53a has, for example, a cylindrical shape. The press-fit region 53a is press-fitted into the first through hole 51c. An outer surface 53c of the press-fit region 53a contacts the inner surface of the first through hole 51c. The outer diameter of the press-fit region 53a before the press-fit region 53a is press-fitted into the first through-hole 51c is larger than the inner diameter of the first through-hole 51c before the press-fit region 53a is press-fitted into the first through-hole 51c.

[0035] The insertion region 53b is located on the opposite side of the head 532 with respect to the press-fit region 53a. The insertion region 53b is connected to the bottom 533. The insertion region 53b has, for example, a cylindrical shape. The outer diameter of the insertion region 53b is smaller than the outer diameter of the press-fit region 53a. The outer diameter of the insertion region 53b is smaller than the inner diameter of the second through hole 52c. The insertion region 53b is inserted into the second through hole 52c. An outer surface 53d of the insertion region 53b is separated from the inner surface of the second through hole 52c.

[0036] Fig. 4 is an enlarged view of portion IV-IV in Fig. 3. As shown in Fig. 4, the head 532 of the connecting member 53 includes a seat 53e. The seat 53e is a surface of the head 532 that protrudes from the outer surface 53c of the shaft portion 531 and faces the first connecting portion 512. The seat 53e is located outside the shaft portion 531 when viewed in the axial direction. The seat 53e has, for example, an annular shape. The seat 53e contacts the main surface 51a of the first connecting portion 512. In other words, the shaft portion 531 of the connecting member 53 is press-fitted into the first through-hole 51c so that the seat 53e abuts against the main surface 51a.

[0037] The first connecting portion 512 includes a region (first region) 51d connecting the inner surface of the first through hole 51c and the main surface 51a. The region 51d is recessed from the main surface 51a. The region 51d is recessed from the inner surface of the first through hole 51c. The region 51d is recessed with respect to an intersection line (first intersection line) 51g between an extension surface 51f of the inner surface of the first through hole 51c and an extension surface 51e of the main surface 51a. In this embodiment, the region 51d is chamfered on the first through hole 51c. The region 51d is formed at the boundary between the inner surface of the first through hole 51c and the main surface 51a. The region 51d is, for example, a C-chamfer, an R-chamfer, or a CR-chamfer. In this embodiment, the region 51d is a C-chamfer. The region 51d has, for example, a circular ring shape when viewed in the axial direction. The region 51d is inclined toward the main surface 51a as it moves toward the outside of the first through-hole 51c along the radial direction of the first through-hole 51c.

[0038] A space G exists between region 51d and connecting member 53. Specifically, space G exists between region 51d and region (second region) 53f of connecting member 53, which connects outer surface 53c of shaft portion 531 and seating surface 53e of head 532. Region 51d is spaced apart from outer surface 53c of shaft portion 531 and seating surface 53e of head 532. Region 51d is spaced apart from the boundary between outer surface 53c and seating surface 53e. Space G is surrounded by outer surface 53c, seating surface 53e, and region 51d.

[0039] As described above, in the cage 5, the shaft portion 531 of the connecting member 53 is press-fitted into the first through hole 51c and inserted into the second through hole 52c with the head portion 532 positioned on the opposite side of the first connecting portion 512 from the second connecting portion 522. This ensures a favorable connection between the first plate member 51 and the second plate member 52. Furthermore, a space G exists between the connecting member 53 and a region 51d of the first connecting portion 512 that connects the inner surface of the first through hole 51c and the main surface 51a. The region 51d of the first connecting portion 512 is recessed, and a space G exists between the region 51d and the region 53f of the connecting member 53. As a result, even if a part of the inner wall portion 5s (see FIG. 7) of the first through hole 51c moves toward the main surface 51a of the first connecting portion 512 opposite the second connecting portion 522 while undergoing plastic deformation due to the press-fitting of the shaft portion 531 of the connecting member 53 into the first through hole 51c, the moved part remains in the space G, and as a result, the moved part is prevented from being compressed by the seat surface 53e of the connecting member 53. As a result, damage to the first plate member 51 caused by stress concentration is prevented. Therefore, the cage 5 can prevent damage to the first plate member 51.

[0040] The region 51d of the first connecting portion 512 is a chamfered portion of the first through-hole 51c, which makes it possible to easily form the space G.

[0041] Next, a method for manufacturing the cage 5 will be described. As shown in FIG. 5, first, a first plate member 51, a second plate member 52, and a connecting member 53 are prepared (step S1). In step S1, the connecting member 53 is not press-fit into the first through hole 51c of the first plate member 51. FIG. 6 is a partial cross-sectional view of the first plate member 51 prepared in step S1. As shown in FIG. 6, a region 51d that connects the inner surface of the first through hole 51c and the main surface 51a of the first connecting portion 512 of the first plate member 51 prepared in step S1 is recessed with respect to an intersection line 51g between an extended surface 51f of the inner surface of the first through hole 51c and an extended surface 51e of the main surface 51a. The region 51d is spaced apart from the intersection line 51g. The extended surface 51f, the extended surface 51e, and the region 51d define a space S.

[0042] Region 51d is chamfered on first through hole 51c. Intersection line 51g has, for example, a circular shape when viewed from the axial direction. Intersection line 51g is the intersection line between the inner surface of first through hole 51c and main surface 51a before region 51d (chamfering) is formed on first through hole 51c. Region 51d is chamfered on intersection line 51g.

[0043] 7 is a diagram showing the first plate member 51 and the connecting member 53 prepared in step S1. As shown in FIGS. 6 and 7, the outer diameter of the shaft portion 531 of the connecting member 53 is larger than the inner diameter of the first through hole 51c of the first plate member 51. Specifically, the outer diameter of the press-fit region 53a of the shaft portion 531 is larger than the inner diameter of the first through hole 51c. The outer diameter of the insertion region 53b of the shaft portion 531 is smaller than the inner diameter of the first through hole 51c.

[0044] When viewed from the axial direction (axial direction) of the first through hole 51c in a state in which the axis 51m of the first through hole 51c and the axis 53m of the shaft portion 531 overlap, the press-fit region 53a partially overlaps with the first connecting portion 512. When viewed from the axial direction of the first through hole 51c, the outer surface 53c of the press-fit region 53a is located outward from the inner surface of the first through hole 51c. When viewed from the axial direction of the first through hole 51c, the outer surface 53c of the press-fit region 53a is located between the inner edge and the outer edge of the region 51d of the first plate member 51.

[0045] The first plate member 51 includes an inner wall portion 5s that overlaps with the press-fit region 53a when viewed from the axial direction of the first through hole 51c. The inner wall portion 5s is a region between the outer surface 53c of the press-fit region 53a of the first plate member 51 and the inner surface of the first through hole 51c when viewed from the axial direction of the first through hole 51c. The inner wall portion 5s is an interference between the press-fit region 53a and the first through hole 51c. When the press-fit region 53a is press-fitted into the first through hole 51c, the inner wall portion 5s is crushed by the press-fit region 53a. The volume of the space S (see FIG. 6) is larger than the volume of the inner wall portion 5s. Step S1 corresponds to the first step.

[0046] Next, the connecting member 53 is press-fitted into the first through hole 51c (step S2). In step S2, the shaft portion 531 of the connecting member 53 is press-fitted into the first through hole 51c such that the bearing surface 53e of the head portion 532 abuts against the main surface 51a of the first connecting portion 512, with the head portion 532 positioned on the opposite side of the second connecting portion 522 with respect to the first connecting portion 512. In step S2, at least a portion of the inner wall portion 5s of the first plate member 51 moves toward the space S while undergoing plastic deformation. As described above, because the volume of the space S is larger than the volume of the inner wall portion 5s, the portion of the inner wall portion 5s that moves while undergoing plastic deformation remains within the space S. The portion of the inner wall portion 5s that moves while undergoing plastic deformation does not protrude from the main surface 51a. When the press-fit region 53a is press-fitted into the first through-hole 51c, the insertion region 53b of the shaft portion 531 protrudes from the main surface 51b of the first connecting portion 512.

[0047] Next, the shaft portion 531 of the connecting member 53 is inserted into the second through hole 52c of the second plate member 52 (step S3). In step S3, the insertion region 53b of the shaft portion 531 is inserted into the second through hole 52c. In step S3, the insertion region 53b is inserted into the second through hole 52c so that the second pocket forming portions 521 and the first pocket forming portions 511 face each other in the axial direction, the second connecting portions 522 and the first connecting portions 512 face each other in the axial direction, and a plurality of pockets 5a for holding a plurality of rolling elements 4 are formed between the second pocket forming portions 521 and the first pocket forming portions 511. In step S3, the second plate member 52 is arranged so that the main surface 51b of the first connecting portion 512 and the main surface 52b of the second connecting portion 522 are in contact with each other. When the insertion region 53b is inserted into the second through-hole 52c, the tip of the insertion region 53b protrudes from the main surface 52a of the second connecting portion 522.

[0048] Next, the other end of the shaft portion 531 of the connecting member 53 (the end portion of the shaft portion 531 opposite to the head portion 532) is crimped (step S4). In step S4, the bottom portion 533 of the connecting member 53 is formed. As a result, the first plate member 51 and the second plate member 52 are connected by the connecting member 53. Steps S2, S3, and S4 correspond to the second step.

[0049] As described above, in step S2 of the method for manufacturing the cage 5, the shaft portion 531 of the connecting member 53 is press-fitted into the first through hole 51c with the head portion 532 positioned on the opposite side of the first connecting portion 512 from the second connecting portion 522, and in step S3, the shaft portion 531 of the connecting member 53 press-fitted into the first through hole 51c is inserted into the second through hole 52c. This allows the first plate member 51 and the second plate member 52 to be suitably connected. Moreover, in the first connecting portion 512 of the first plate member 51 prepared in step S1, a region 51d connecting the inner surface of the first through hole 51c and the main surface 51a is recessed with respect to an intersection line 51g between an extended surface 51f of the inner surface of the first through hole 51c and an extended surface 51e of the main surface 51a. As a result, even if a part of the inner wall portion 5s of the first through hole 51c moves toward the main surface 51a of the first connecting portion 512 opposite to the second connecting portion 522 while undergoing plastic deformation due to the press-fitting of the shaft portion 531 of the connecting member 53 into the first through hole 51c, the moved part is prevented from being compressed by the connecting member 53. As a result, damage to the first plate member 51 caused by stress concentration is prevented. Therefore, according to this manufacturing method, damage to the first plate member 51 can be prevented.

[0050] The region 51d of the first plate member 51 prepared in step S1 is a chamfer applied to the first through-hole 51c, which makes it possible to easily form the region 51d.

[0051] In the first plate member 51 prepared in step S1, the volume of the space S defined by the extension surface 51f of the inner surface of the first through hole 51c, the extension surface 51e of the main surface 51a, and the region 51d is larger than the volume of the inner wall portion 5s of the first plate member 51 that overlaps with the shaft portion 531 when viewed from the axial direction of the first through hole 51c with the axis 51m of the first through hole 51c of the first plate member 51 prepared in step S1 overlapping with the axis 53m of the shaft portion 531 of the connecting member 53 prepared in step S1. As a result, even if a portion of the inner wall portion 5s of the first through hole 51c undergoes plastic deformation and moves toward the main surface 51a opposite the second connecting portion 522 in the first connecting portion 512 due to the pressing of the shaft portion 531 of the connecting member 53 into the first through hole 51c, the moved portion remains reliably in the space S, and as a result, the moved portion is reliably prevented from being compressed by the connecting member 53.

[0052] The present invention is not limited to the above-described embodiment. In the embodiment, the region 51d of the first plate member 51 prepared in step S1 is recessed relative to the intersection line 51g. However, the region 51d does not have to be recessed relative to the intersection line 51g. In other words, the intersection line 51g does not have to be chamfered. In this case, the region (second region) 53f of the connecting member 53 prepared in step S1, which connects the outer surface 53c of the shaft portion 531 and the seating surface 53e of the head portion 532, may be recessed relative to the intersection line (second intersection line) 53g between the extension of the outer surface 53c and the extension of the seating surface 53e (see FIG. 7). The region 53f may be recessed from the outer surface 53c or from the seating surface 53e. It is sufficient that at least one of the region 51d and the region 53f is recessed. When the connecting member 53 is press-fitted into the first through-hole 51c, a space may be present between the connecting member 53 and a region of the first connecting portion 512 that connects the inner surface of the first through-hole 51c and the main surface 51a. [Explanation of symbols]

[0053] 4...rolling element, 5...retainer, 5a...pocket, 5s...inner wall portion, 51...first plate member, 51a...main surface, 51c...first through hole, 51d...region (first region), 51e...extension surface, 51f...extension surface, 51g...intersection line (first intersection line), 51m...axis, 52...second plate member, 52c...second through hole, 53...connecting member, 53c...outer surface, 53e...seat surface, 53f...region (second region), 53g...intersection line (second intersection line), 53m...axis, 511...first pocket forming portion, 512...first connecting portion, 521...second pocket forming portion, 522...second connecting portion, 531...shaft portion, 532...head portion, G...space, S...space.

Claims

1. A cage for holding a plurality of rolling elements arranged along a circumferential direction so that they can roll freely, a first plate member having an annular shape when viewed from the axial direction; a second plate member that has an annular shape when viewed in the axial direction and faces the first plate member in the axial direction; a connecting member that connects the first plate member and the second plate member, the first plate member includes a plurality of first pocket forming portions aligned along the circumferential direction, and a first connecting portion located between a pair of adjacent first pocket forming portions among the plurality of first pocket forming portions, the second plate member includes a plurality of second pocket forming portions that are aligned along the circumferential direction and that face the plurality of first pocket forming portions in the axial direction, and a second connecting portion that is located between a pair of adjacent second pocket forming portions among the plurality of second pocket forming portions and that faces the first connecting portion in the axial direction, the plurality of first pocket forming portions and the plurality of second pocket forming portions define a plurality of pockets for holding the plurality of rolling elements; a first through hole is formed in the first connecting portion, a second through hole is formed in the second connecting portion, The connecting member includes a shaft portion and a head portion formed at one end of the shaft portion, the shaft portion of the connecting member is press-fitted into the first through hole and inserted into the second through hole with the head portion positioned on the opposite side of the first connecting portion from the second connecting portion, a seat surface of the head portion facing the first connecting portion abutting against a main surface of the first connecting portion on an opposite side to the second connecting portion, At least one of a first region of the first connecting portion connecting an inner surface of the first through hole and the main surface and a second region of the connecting member connecting an outer surface of the shaft portion and the seat surface of the head is recessed, A space exists between the first region and the second region.

2. The cage according to claim 1 , wherein the first region is a chamfer provided on the first through hole.

3. A method of manufacturing a cage for holding a plurality of rolling elements arranged in a circumferential direction so as to be free to roll, comprising the steps of: a first step of preparing an annular first plate member including a plurality of first pocket forming portions lined up along the circumferential direction and a first connecting portion located between a pair of adjacent first pocket forming portions of the plurality of first pocket forming portions, an annular second plate member including a plurality of second pocket forming portions lined up along the circumferential direction and a second connecting portion located between a pair of adjacent second pocket forming portions of the plurality of second pocket forming portions, and a connecting member for connecting the first plate member and the second plate member; a second step of connecting the first plate member and the second plate member with the connecting member, a first through hole is formed in the first connecting portion of the first plate member prepared in the first step, a second through hole is formed in the second connecting portion of the second plate member prepared in the first step, The connecting member prepared in the first step includes a shaft portion and a head portion formed at one end of the shaft portion, In the second step, the shank of the connecting member is press-fitted into the first through hole such that, with the head positioned on the opposite side of the first connecting portion from the second connecting portion, a seat surface of the head facing the first connecting portion abuts on a main surface of the first connecting portion on the opposite side of the second connecting portion from the second connecting portion, and then the shank is inserted into the second through hole such that the plurality of second pocket forming portions and the plurality of first pocket forming portions face each other in the axial direction, the second connecting portion and the first connecting portion face each other in the axial direction, and a plurality of pockets for holding the plurality of rolling elements are formed between the plurality of second pocket forming portions and the plurality of first pocket forming portions, a first region of the first connecting portion of the first plate member prepared in the first step that connects the inner surface of the first through hole to the main surface is recessed with respect to a first intersection line between an extension surface of the inner surface and an extension surface of the main surface, or a second region of the connecting member prepared in the first step that connects the outer surface of the shaft portion to the seat surface of the head is recessed with respect to a second intersection line between an extension surface of the outer surface and an extension surface of the seat surface.

4. The method for manufacturing a cage according to claim 3 , wherein the first region of the first plate member prepared in the first step is a chamfer formed in the first through hole.

5. 5. A method for manufacturing a retainer as described in claim 3 or 4, wherein the volume of the space defined by the extended surface of the inner surface of the first through hole, the extended surface of the main surface, and the first region of the first plate member prepared in the first step is larger than the volume of the inner wall portion of the first plate member that overlaps with the shaft portion when viewed from the axial direction of the first through hole with the axis of the first through hole of the first plate member prepared in the first step overlapping the axis of the shaft portion of the connecting member prepared in the first step.

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