holder, bearing, reducer

Abstract

The present application provides a retainer, bearing, speed reducer. The retainer of the present application is a retainer (1) of a bearing (1A) that holds a plurality of rolling bodies (2) about a center axis (F3), wherein the retainer is provided with: a side peripheral portion (1a) that houses a plurality of rolling bodies along the periphery of the center axis; a circular ring plate-shaped end face portion (1b, 1c) that is disposed from an end portion (1a1, 1a2) of the side peripheral portion in the direction of the center axis toward the radial direction based on the center axis; and a reinforcing portion (1d, 1e) disposed at the end face portion.

Description

Technical Field

[0001] This invention relates to retainers, bearings, and speed reducers.

[0002] This application claims priority based on Japanese Patent Application No. 2020-084679, filed on May 13, 2020, which is incorporated herein by reference. Background Technology

[0003] For industrial robots, machine tools, and similar applications, reducers equipped with needle roller bearings are sometimes used. In a needle roller bearing, numerous rolling elements (needles) held in a cage pocket (opening) are sandwiched between an inner and outer ring to form the bearing. Multiple pockets (openings) are arranged circumferentially relative to the bearing's central axis. The cage has column portions formed between adjacent pockets (openings).

[0004] In reducers with an RV rating, the needle roller filler ratio of the needle roller bearings used in the crankshaft section tends to increase with increasing output density. This tendency is particularly pronounced in eccentric oscillating reducers.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent No. 2628674 Summary of the Invention

[0008] The problem the invention aims to solve

[0009] However, if the needle roller fill rate increases, the number of pockets (openings) for the needle rollers to insert into the retainer increases. Therefore, in the circumferential direction relative to the central axis, the distance between adjacent pockets (openings) decreases, and the circumferential dimension of the column becomes smaller. Consequently, the strength of the retainer decreases.

[0010] In speed reducers used in robots, a skew force is generated in the needle rollers of the needle roller bearing. This skew force can cause the needle rollers to tilt.

[0011] When the needle rollers of a needle roller bearing are tilted, they collide with the contour of the retainer's pocket (opening) in an tilted state. Consequently, the needle rollers collide with the end face side along the central axis and the cylindrical side circumferentially along the central axis at the contour of the pocket (opening). This results in stress concentration at the angled root portion (R) of the cylindrical portion of the retainer's pocket (opening) contour.

[0012] In particular, for retainers with reduced strength, there is sometimes a problem where the area near the retainer's pocket breaks due to stress concentration.

[0013] The present invention aims to achieve the following objectives: to provide a structure that can improve the strength of the retainer for needle roller bearings; and to provide a retainer, bearing, and reducer that can prevent damage caused by oblique forces with a simple structure.

[0014] Solution for solving the problem

[0015] The retainer of one technical solution of the present invention solves the above problems in the following way:

[0016] This retainer is a retainer for bearings that holds multiple rolling elements around a central axis, wherein...

[0017] The retainer has:

[0018] The side periphery houses a plurality of the rolling elements around the central axis;

[0019] The annular plate-shaped end portion, with its ends on the lateral periphery arranged radially relative to the central axis; and

[0020] A reinforcing part is disposed on the end face.

[0021] According to a technical solution of the present invention, when the rolling element tilts relative to the central axis due to the oblique force and abuts against the side peripheral portion, the strength of the side peripheral portion is increased by the reinforcing portion, thereby preventing the retainer from breaking.

[0022] The retainer of one technical solution of the present invention can be configured as follows:

[0023] In the aforementioned retainer,

[0024] The reinforcing part is formed in a circular shape.

[0025] The retainer of one technical solution of the present invention can be configured as follows:

[0026] In the aforementioned retainer,

[0027] The reinforcing part is a thick-walled part that is integrally formed with the end face and has a thickness greater than that of the end face in the direction along the central axis.

[0028] The retainer of one technical solution of the present invention can be configured as follows:

[0029] In the aforementioned retainer,

[0030] The ends of the reinforcing part and the rolling element are able to contact each other in the direction along the central axis.

[0031] The retainer of one technical solution of the present invention can be configured as follows:

[0032] In the aforementioned retainer,

[0033] The peripheral portion has end faces at both ends along the central axis.

[0034] The retainer of one technical solution of the present invention can be configured as follows:

[0035] In the aforementioned retainer,

[0036] The reinforcing portion is formed on the opposing surfaces between the end faces.

[0037] The retainer of one technical solution of the present invention can be configured as follows:

[0038] In the aforementioned retainer,

[0039] The end face and the reinforcing part are integrally formed by stamping.

[0040] The retainer of one technical solution of the present invention solves the above problems in the following way:

[0041] This retainer is a retainer for bearings that holds multiple rolling elements around a central axis, wherein...

[0042] The retainer has:

[0043] The side portion has a rectangular opening space around the central axis for receiving a plurality of the rolling elements;

[0044] An annular plate-shaped end portion, which is arranged radially from the end of the side periphery in a direction along the central axis, relative to the central axis; and

[0045] A limiting portion protrudes at the peripheral portion towards the end face that forms the contour of the opening space, closer to the rolling element.

[0046] According to a technical solution of the present invention, when the rolling element tilts relative to the central axis due to an oblique force, it abuts against the limiting portion instead of directly abutting against the opening space. Therefore, stress does not concentrate at the corner portion of the opening space profile on the side periphery. Consequently, damage to the retainer can be prevented.

[0047] The retainer of one technical solution of the present invention can be configured as follows:

[0048] In the aforementioned retainer,

[0049] The limiting part and the end face are integrated.

[0050] The limiting portion is positioned close to the rolling element from the inner periphery of the end face along the central axis.

[0051] The retainer of one technical solution of the present invention can be configured as follows:

[0052] In the aforementioned retainer,

[0053] The end face and the limiting part are integrally formed by stamping.

[0054] The retainer of one technical solution of the present invention can be configured as follows:

[0055] In the aforementioned retainer,

[0056] The end of the opening space, which is radially observed relative to the central axis, is separated from the end of the rolling element visible from the opening space along the central axis.

[0057] The retainer of one technical solution of the present invention can be configured as follows:

[0058] In the aforementioned retainer,

[0059] The lateral portion has end faces at both ends in the direction of the central axis.

[0060] The retainer of one technical solution of the present invention can be configured as follows:

[0061] In the aforementioned retainer,

[0062] The limiting portion is formed on the opposing surfaces between the end faces.

[0063] Another technical solution of the present invention provides a bearing that can have:

[0064] The outer ring is formed in a circular shape and has an outer rolling surface facing the radially inward side;

[0065] An inner ring, coaxially arranged with the outer ring, has an inner rolling surface facing outwards in the radial direction; a plurality of rolling elements that roll on the inner rolling surface and the outer rolling surface; and

[0066] The retainer described in any of the preceding claims holds a plurality of the rolling elements.

[0067] Another technical solution of the present invention provides a speed reducer that can include:

[0068] The outer cylinder has internal teeth arranged circumferentially on its inner circumferential surface;

[0069] An eccentric oscillating gear having external teeth that mesh with the internal teeth of the outer cylinder;

[0070] A crankshaft, connected to a drive source, for oscillating the eccentric oscillating gear; and

[0071] A gear carrier that supports the crankshaft and rotates relative to the outer cylinder.

[0072] The crankshaft is supported on the gear carrier by the aforementioned bearings.

[0073] The effects of the invention

[0074] According to the present invention, the following effects can be achieved: a structure that can improve the strength of the retainer for needle roller bearings can be provided; a retainer, bearing, and reducer that can prevent breakage caused by oblique forces with a simple structure can be provided. Attached Figure Description

[0075] Figure 1 This is a front view obtained by partial cross-section along the central axis direction, showing the first embodiment of the retainer and bearing of the present invention.

[0076] Figure 2 This is a cross-sectional view along the central axis of the first embodiment of the retainer of the present invention.

[0077] Figure 3 This is a side view obtained by viewing the first embodiment of the retainer of the present invention in a direction orthogonal to the central axis.

[0078] Figure 4 This is a schematic enlarged view showing the elements in a cross section in the direction aligned with the central axis in the first embodiment of the retainer of the present invention.

[0079] Figure 5 This is a cross-sectional view along the central axis of the second embodiment of the retainer, bearing, and reducer of the present invention.

[0080] Figure 6 This is a cross-sectional view along the central axis of the third embodiment of the retainer of the present invention.

[0081] Explanation of reference numerals in the attached figures

[0082] 1. Retainer; 1A. Bearing; 1a. Side peripheral part; 1a1, 1a2. End; 1b, 1c. End face; 1d, 1e. Protrusion (reinforcing part, restricting part); 1p. Opening space; 1p1. End face; F3. Central axis; F4. Axis; 2. Needle roller (rolling element). Detailed Implementation

[0083] Hereinafter, a first embodiment of the retainer, bearing, and reducer of the present invention will be described based on the accompanying drawings.

[0084] Figure 1This is a front view obtained by partially sectionally viewing the retainer and bearing in the direction of the central axis in this embodiment. Figure 2 This is a side sectional view along the central axis of the retainer in this embodiment. Figure 3 This is a side view of the retainer in this embodiment, taken from the outside in a direction orthogonal to the central axis. Figure 4 This is a schematic diagram along the central axis showing the dimensions of the retainer in this embodiment. In the figure, reference numeral 1 indicates the retainer.

[0085] like Figures 1-3 As shown, the retainer 1 in this embodiment is used to hold a bearing with multiple rolling elements (needle rollers) 2 around the central axis F3.

[0086] like Figures 1-3 As shown, the retainer 1 of this embodiment includes: a peripheral portion 1a having an opening space 1p that serves as a pocket for receiving a plurality of rolling elements (needle rollers) 2 around a central axis F3; annular plate-shaped end portions 1b and 1c arranged radially from the two ends 1a1 and 1a2 of the peripheral portion 1a in the direction of the central axis F3 toward the central axis F3; and reinforcing portions 1d and 1e disposed on the end portions 1b and 1c.

[0087] In other words, the retainer 1 has: a peripheral portion 1a, which has a diameter that is approximately cylindrical and larger than the pitch circle diameter of the needle roller arrangement; flange-shaped end portions 1b and 1c, which protrude from the two ends 1a1 and 1a2 of the annular peripheral portion 1a toward the radially inward side relative to the central axis F3; an opening space 1p, which is a plurality of recesses arranged circumferentially on the cylindrical surface of the peripheral portion 1a, with column portions formed between them, for inserting the needle rollers 2 respectively; and protrusions (ribs) 1d and 1e, which serve as limiting portions (reinforcing portions) for positioning the needle rollers 2 at their end faces in the direction of the central axis F3.

[0088] like Figures 1-3 As shown, the rolling element (needle roller) 2 has a generally cylindrical shape. The rolling element (needle roller) 2 has an axis F4 parallel to the central axis F3. Multiple rolling elements (needle rollers) 2 are arranged about the central axis F3 with their axes F4 parallel to each other. The multiple rolling elements (needle rollers) 2 are arranged at equal distances from each other in the circumferential direction relative to the central axis F3. The retainer 1 holds the multiple rolling elements (needle rollers) 2 in this state so that they can rotate while moving circumferentially relative to the central axis F3.

[0089] The side circumference 1a forms a generally cylindrical surface around the central axis F3. The side circumference 1a is defined as having a width dimension T1a along the direction of the central axis F3 (see reference). Figure 4The thickness of the lateral portion 1a is approximately the same around the central axis F3. The thickness Ta along the direction of the central axis F3 is defined as (see reference). Figure 4 The same applies over a full circumference around the central axis F3.

[0090] The lateral portion 1a is set to the separation distance between itself and the central axis F3, that is, the radial dimension is approximately equal along the entire length of the direction along the central axis F3.

[0091] Furthermore, the shape of the side peripheral portion 1a is not limited to the shape described above, and can be deformed according to the shape of the bearing to be housed.

[0092] Multiple opening spaces 1p are formed circumferentially in the side peripheral portion 1a. Multiple opening spaces 1p are provided circumferentially in the side peripheral portion 1a. The opening spaces 1p are located in the storage position of the needle roller (rolling element) 2.

[0093] like Figures 1-3 As shown, the opening space 1p has a roughly rectangular outline shape when viewed from the radially outer side of the side circumference 1a.

[0094] The dimension Tp of the open space 1p along the central axis F3 (refer to) Figure 4 The length T2 of the needle roller (rolling element) 2 along the central axis F3 is formed (refer to...). Figure 4 )big.

[0095] The circumferential dimension of the opening space 1p relative to the central axis F3 is larger than the length dimension of the needle roller (rolling element) 2 in the direction orthogonal to the central axis F3.

[0096] In the peripheral portion 1a, the end portion 1a1 in the direction of the central axis F3 is provided with a flange-shaped end portion 1b that protrudes radially inward with respect to the central axis F3. In addition, in the peripheral portion 1a, the end portion 1a2 in the direction of the central axis F3 is provided with a flange-shaped end portion 1c that protrudes radially inward with respect to the central axis F3.

[0097] like Figures 1-3 As shown, end faces 1b and 1c are designed as annular plates (annular plate shape) extending in a direction orthogonal to the central axis F3. End faces 1b and 1c have approximately the same profile shape when viewed along the central axis F3. End faces 1b and 1c are formed orthogonal to the side periphery 1a. End faces 1b and 1c have approximately equal outer diameter dimensions over the entire circumference of the central axis F3. End faces 1b and 1c have approximately equal inner diameter dimensions over the entire circumference of the central axis F3.

[0098] End faces 1b and 1c have approximately equal radial dimensions over the entire circumference of the central axis F3. The radial dimensions of end faces 1b and 1c relative to the central axis F3 are set to be larger than the radius of the needle roller (rolling element) 2 about the axis F4. The radial dimensions of end faces 1b and 1c relative to the central axis F3 may also be smaller than the radius of the needle roller (rolling element) 2 about the axis F4.

[0099] End face 1b is defined as the thickness dimension Tb along the direction of the central axis F3 (refer to...). Figure 4 The thickness of the end face 1b is approximately the same around the central axis F3. The thickness Tb of the end face 1b is defined as the thickness along the direction of the central axis F3 (refer to...). Figure 4 The thickness is approximately the same along the entire length radially relative to the central axis F3. The end portion 1c is defined as the thickness dimension Tc in the direction along the central axis F3 (refer to...). Figure 4 The thickness is approximately the same around the central axis F3. The end face 1c is defined as the thickness Tc along the direction of the central axis F3 (refer to...). Figure 4 It is roughly the same along the entire radial length based on the central axis F3.

[0100] The thickness dimension Tb of end face 1b (refer to) Figure 4 ) and the thickness dimension Tc of the end face 1c (refer to Figure 4 All are formed equally. The thickness Tb of the end face 1b (refer to...) Figure 4 ) and the thickness dimension Tc of the end face 1c (refer to Figure 4 All are set to the same thickness dimension Ta as the side peripheral portion 1a (refer to...). Figure 4 )equal.

[0101] like Figures 1-3 As shown, on end face 1b, a protrusion (spur) 1d, serving as a limiting part or reinforcement, is formed at the radially inner end relative to the central axis F3 and at a position opposite to end face 1c. On end face 1c, a protrusion (spur) 1e, also serving as a limiting part or reinforcement, is formed corresponding to the protrusion (spur) 1d at the radially inner end relative to the central axis F3 and at a position opposite to end face 1b. Protrusions (spurs) 1d and 1e are formed on the opposing surfaces of end face 1b and end face 1c.

[0102] The protrusions (spurs) 1d and 1e, which serve as limiting or reinforcing parts, are formed continuously in a circular shape around the entire circumference of the central axis F3. The protrusions (spurs) 1d and 1e are formed as thick-walled parts that are thicker than the end faces 1b and 1c in the direction along the central axis F3, thus serving as limiting or reinforcing parts.

[0103] The protrusion (spur) 1d, which serves as a limiting or reinforcing part, is integrally formed with the end face 1b. The protrusion (spur) 1e, which serves as a limiting or reinforcing part, is integrally formed with the end face 1c.

[0104] The protrusion (rib) 1d, which serves as a limiting or reinforcing part, is defined as having a radial width dimension Td along the central axis F3 (see reference). Figure 4 The ridges are approximately the same around the central axis F3. The protrusion (rib) 1e, which serves as a limiting or reinforcing part, is defined as having a radial width Te along the central axis F3 (see reference). Figure 4 The same applies over a full circumference around the central axis F3.

[0105] The width dimension Td of the protrusion (spur) 1d that serves as a limiting or reinforcing part (refer to) Figure 4 The width Te of the protrusion (rib) 1e, which serves as a limiting or reinforcing part, is (see reference). Figure 4 All are formed equally.

[0106] The width dimension Td of the protrusion (spur) 1d that serves as a limiting or reinforcing part (refer to) Figure 4 The width Te of the protrusion (rib) 1e, which serves as a limiting or reinforcing part, is (see reference). Figure 4 All of these are related to the thickness dimension Ta of the side peripheral portion 1a (refer to...). Figure 4 They are formed in equal proportions.

[0107] The protrusion (spur) 1d, which serves as a limiting part or a reinforcing part, is visible from the opening space 1p when viewed radially outward from the central axis F3. That is, the protrusion (spur) 1d, which serves as a limiting part or a reinforcing part, protrudes towards the center of the opening space 1p relative to the end face 1p1 of the outline of the opening space 1p in the direction along the central axis F3.

[0108] The protrusion (spur) 1e, which serves as a limiting part or a reinforcing part, is visible from the opening space 1p when viewed radially outward from the central axis F3. That is, the protrusion (spur) 1e, which serves as a limiting part or a reinforcing part, protrudes towards the center of the opening space 1p relative to the contour of the opening space 1p in the direction along the central axis F3.

[0109] Along the central axis F3, the distance Tde between protrusion (rib) 1d and protrusion (rib) 1e (refer to...) Figure 4 The distance Tp between a pair of parallel sides in the outline of the open space 1p along the direction of the central axis F3 (refer to...) Figure 4 Small. Similarly, in the direction along the central axis F3, the distance Tde between the protrusion (rib) 1d and the protrusion (rib) 1e (refer to) Figure 4 The length T2 of the rolling element (needle roller) 2 along the direction of the central axis F3 is set (refer to...). Figure 4 Approximately equal to, or set to be greater than, the length T2 of the rolling element (needle roller) 2 along the direction of the central axis F3 (refer to) Figure 4 Slightly larger.

[0110] Distance Tde (reference) Figure 4 ) and distance Tp (refer to Figure 4 The difference is set to be equal along the entire length of one side extending circumferentially based on the central axis F3 in the open space 1p, which is a rectangular outline.

[0111] Distance Tde (reference) Figure 4 ) and length T2 (refer to Figure 4 The difference is set to be equal along the entire length of one side of the opening space 1p, which is a rectangular outline, in the circumferential direction based on the central axis F3.

[0112] The opposing end faces of protrusions (ribs) 1d and 1e are parallel in a direction orthogonal to the central axis F3. Surface treatments such as smoothing and deburring are performed on the opposing end faces of protrusions (ribs) 1d and 1e.

[0113] The end face of the protrusion (rib) 1d and the end face of the protrusion (rib) 1e maintain the same distance Tde in the radial direction based on the central axis F3 (refer to...). Figure 4 In other words, the end face of the protrusion (rib) 1d and the end face of the protrusion (rib) 1e maintain the same distance Tde in their thickness direction (refer to...). Figure 4 ).

[0114] The end face of the protrusion (rib) 1d and the end face of the protrusion (rib) 1e maintain the same distance Tde in the circumferential direction based on the central axis F3 (refer to...). Figure 4 ).

[0115] The end faces of the protrusion (rib) 1d and the protrusion (rib) 1e can be positioned radially relative to the central axis F3, close to the central axis F4. Alternatively, the end faces of the protrusion (rib) 1d and the protrusion (rib) 1e can be positioned radially relative to the central axis F3, encompassing the axis F4.

[0116] The retainer 1 in this embodiment includes: a circumferential portion 1a along the central axis F3; an opening space 1p having multiple openings in the circumferential direction of the circumferential portion 1a, serving as a storage location for the needle rollers (rolling elements) 2; flange-shaped end portions 1b and 1c extending radially inward from the ends 1a1 and 1a2 of the circumferential portion 1a along the central axis F3; and protrusions (reinforcing portions, limiting portions) 1d and 1e protruding radially from the inner circumferential ends of the end portions 1b and 1c along the central axis F3 toward the center of the outline of the opening space 1p. The protrusions (reinforcing portions, limiting portions) 1d and 1e protrude toward the center of the outline of the opening space 1p relative to the edge 1p1 of the rectangular outline of the opening space 1p along the central axis F3.

[0117] Next, the method for forming the retainer in this embodiment will be described.

[0118] In the method of forming the retainer 1 in this embodiment, the sheet metal is integrally formed by stamping. At this time, in the formation of the retainer 1, the side peripheral portion 1a and the end portions 1b and 1c are bent so that the radial cross section with respect to the central axis F3 is approximately U-shaped, and the ends in the circumferential direction with respect to the central axis F3 are connected to form a ring shape.

[0119] Furthermore, at the end faces 1b and 1c, the inner circumferential ends based on the central axis F3 are bent toward each other and approach each other, thereby forming protrusions (reinforcing parts, limiting parts) 1d and 1e.

[0120] Furthermore, surface treatments such as deburring are performed on the end faces of the protrusions (reinforcing parts, restricting parts) 1d and 1e.

[0121] Thus, the radial section based on the central axis F3 is set to a C-shape that is approximately rectangular to form the retainer 1.

[0122] Furthermore, the bending steps, surface treatment steps, etc., can be set appropriately according to the ease of processing, and are not limited to the steps mentioned above.

[0123] The state of the retainer 1 and the needle roller (rolling element) 2 in this embodiment is explained.

[0124] In the case of retainer 1, the axis F4 is tilted and the needle roller (rolling element) 2 is tilted relative to the central axis F3.

[0125] Among them, retainer 1 is used as a bearing. Therefore, as Figure 1 As shown, the outer ring Or is located radially outside the retainer 1 relative to the central axis F3. Additionally, as... Figure 1As shown, the inner ring Ir is located inside the retainer 1 in the radial direction relative to the central axis F3.

[0126] Therefore, we can consider the state of the needle roller (rolling element) 2 being inclined circumferentially along the central axis F3.

[0127] Thus, for the retainer 1 in this embodiment, when the axis F4 is tilted and the needle roller (roller body) 2 is tilted relative to the central axis F3, the protrusions (reinforcing parts, limiting parts) 1d and 1e first contact the end face of the needle roller (roller body) 2. In this state, the needle roller (roller body) 2 does not contact the edge of the rectangular outline of the opening space 1p. Therefore, stress will not be generated in the peripheral portion 1a near the outline of the opening space 1p due to the contact of the needle roller (roller body) 2. In particular, the needle roller (roller body) 2 will not contact the portion of the opening space 1p near the corner of the rectangular outline, and stress concentration will not occur.

[0128] Furthermore, when the needle roller (rolling element) 2 is tilted and first contacts the protrusions (reinforcing parts, limiting parts) 1d and 1e, the end faces 1b and 1c deform in such a way that the protrusions (reinforcing parts, limiting parts) 1d and 1e move away from each other in the direction of the central axis F3. That is, the end faces 1b and 1c deform in such a way that they move away from each other. At this time, each end face 1b and end face 1c deforms in such a way that the inner peripheral side where the protrusions (reinforcing parts, limiting parts) 1d and 1e are formed moves away from each other in the direction along the central axis F3. In contrast, deformation is suppressed on the outer peripheral side of the end faces 1b and 1c that is connected to the side peripheral part 1a.

[0129] This prevents stress concentration at the peripheral portion 1a. Furthermore, by increasing the filler ratio of the needle rollers, even the thinner and weaker peripheral portion 1a can be prevented from breaking. Moreover, it allows for a longer lifespan for the retainer 1.

[0130] In addition, in retainer 1, the following situation is taken into consideration: there is an oblique force acting, the axis F4 is not tilted, but the needle roller (rolling element) 2 moves along the central axis F3.

[0131] Thus, for the retainer 1 of this embodiment, when the axis F4 is not tilted and the needle roller (rolling element) 2 has moved along the central axis F3, the protrusions (reinforcing parts, limiting parts) 1d and 1e first contact the end face of the needle roller (rolling element) 2. In this state, the needle roller (rolling element) 2 does not contact the edge of the rectangular outline of the opening space 1p. Therefore, stress will not be generated in the peripheral portion 1a near the outline of the opening space 1p due to the contact of the needle roller (rolling element) 2.

[0132] Furthermore, when the needle roller 2 moves and first contacts the protrusion (reinforcing part, limiting part) 1d or the protrusion (reinforcing part, limiting part) 1e, the end face 1b or the end face 1c deforms such that the protrusions (reinforcing parts, limiting parts) 1d and 1e move away from each other in the direction of the central axis F3. That is, the end face 1b and the end face 1c deform in a way that moves away from each other. At this time, each end face 1b and the end face 1c deforms such that the inner peripheral side where the protrusions (reinforcing parts, limiting parts) 1d and the protrusions (reinforcing parts, limiting parts) 1e are formed moves away from each other in the direction along the central axis F3. In contrast, deformation is suppressed on the outer peripheral side of the end face 1b and the end face 1c that is connected to the side peripheral part 1a.

[0133] Therefore, the retainer 1 of this embodiment can prevent stress concentration at the peripheral portion 1a, prevent damage, and extend the service life of the retainer 1. Thus, it is not necessary to increase the curvature R of the corner of the contour forming the opening space 1p to maintain strength; therefore, the gap between the retainer 1 and the rolling element 2 can be reduced, enabling miniaturization.

[0134] Furthermore, the retainer 1 of this embodiment utilizes a simple structure that can be integrally formed by bending four strips, thereby reducing the number of forming processes and the number of forming parts, thus enabling low-cost manufacturing.

[0135] For the retainer 1 in this embodiment, it is also possible to... Figure 4 The dimensions shown are set as follows to satisfy the various relationships.

[0136] T2≤Tde

[0137] Tde < Tp

[0138] Tp < Tbc

[0139] Tbc < T1a

[0140] Td = Te = Tb = Tc = Ta

[0141] Next, the bearing in this embodiment will be described.

[0142] like Figure 1 As shown, the bearing 1A in this embodiment has the aforementioned retainer 1 and a plurality of rolling elements (needle rollers) 2, an outer ring Or and an inner ring Ir.

[0143] Bearing 1A rotates around the central axis F3.

[0144] The outer ring Or is formed in a circular shape and has an outer rolling surface that is radially inward relative to the central axis F3.

[0145] The inner ring Ir is coaxially configured with the outer ring Or and has an inner rolling surface that is radially outward relative to the central axis F3.

[0146] In addition, Figure 1 In the diagram, the outer ring Or and the inner ring Ir only indicate the positions of their respective rolling surfaces.

[0147] Multiple rolling elements (needle rollers) 2 roll on the inner and outer rolling surfaces.

[0148] As described above, the bearing 1A in this embodiment can prevent stress concentration in the retainer 1 and thus suppress breakage. Therefore, it is possible to achieve breakage prevention, long service life, and miniaturization as the bearing 1A.

[0149] Hereinafter, a second embodiment of the retainer, bearing, and reducer of the present invention will be described based on the accompanying drawings.

[0150] Figure 5 This is a cross-sectional view along the axial direction showing the retainer, bearing, and reducer in this embodiment. In the figure, reference numeral 100 indicates the reducer. In this embodiment, the difference from the first embodiment described above is that points related to the reducer are labeled with the same reference numerals as those in the first embodiment described above, and their descriptions are omitted.

[0151] like Figure 5 As shown, the reducer 100 of this embodiment includes a housing 200, a gear section (external gear member) 300, and three crankshaft assemblies 400. The housing 200 houses the gear section 300 and the three crankshaft assemblies 400.

[0152] In this embodiment, the reducer 100 is configured as an eccentric oscillating reducer.

[0153] The housing 200 includes an outer shell (outer cylinder portion) 210, a gear carrier portion (gear carrier) 220, and two main bearings 230. The gear carrier portion 220 is disposed within the outer shell (outer cylinder portion) 210. The two main bearings 230 are disposed between the outer shell (outer cylinder portion) 210 and the gear carrier portion 220. The two main bearings 230 enable relative rotational movement between the outer shell (outer cylinder portion) 210 and the gear carrier portion 220. In this embodiment, the output portion of the reducer 100 is exemplified by either the outer shell (outer cylinder portion) 210 or the gear carrier portion 220.

[0154] exist Figure 5The central axis (main shaft) F0 of the reducer 100 is defined as the rotation center axis of the two main bearings 230. With the outer casing (outer cylinder) 210 fixed, the gear carrier 220 rotates around the main shaft F0. With the gear carrier 220 fixed, the outer casing (outer cylinder) 210 rotates around the main shaft F0. That is, one of the outer casing (outer cylinder) 210 and the gear carrier 220 can rotate relative to the other about the main shaft F0.

[0155] In this embodiment, the direction along the central axis (main shaft) F0 of the reducer 100, which serves as the rotational center axis of the two main bearings 230, is referred to as the axial direction.

[0156] A flange (mounting flange) 215 is provided around the outer periphery of the cylindrical outer casing (outer cylinder portion) 210. A plurality of mounting holes 216 are formed around the periphery of the flange 215 at intervals from each other. The flange 215 is used, for example, to fit the reducer 100 into the insert portion.

[0157] The outer casing (outer cylinder portion) 210 includes an outer cylinder 211 and a plurality of internal toothed pins (internal teeth) 212. The outer cylinder 211 defines a cylindrical internal space for accommodating the gear carrier portion 220, the gear portion 300, and the crankshaft assembly 400. Each internal toothed pin 212 is a cylindrical member extending substantially parallel to the main shaft F0. Each internal toothed pin 212 is embedded in a groove formed in the inner wall of the outer cylinder 211. Thus, each internal toothed pin 212 is properly held by the outer cylinder 211.

[0158] Multiple internal toothed pins 212 are arranged around the main shaft F0 at approximately constant intervals. The semi-circular surface of each internal toothed pin 212 protrudes from the inner wall of the outer cylinder 211 toward the main shaft F0. Thus, the multiple internal toothed pins 212 function as internal teeth that mesh with the gear section 300.

[0159] The gear carrier portion 220 includes a base (first component) 221, an end plate portion (second component) 222, a locating pin 223, and a support bolt (fixing bolt) 224. The gear carrier portion 220 is generally cylindrical in shape. A through hole 229 concentric with the main shaft F0 is formed in the gear carrier portion 220.

[0160] The base (first component) 221 includes a base plate portion 225 and three shaft portions 226. The three shaft portions 226 extend from the base plate portion 225 toward the end plate portion (second component) 222. A threaded hole 227 and a reamer hole 228 are formed on the top surface of each of the three shaft portions 226. A locating pin 223 is inserted into the reamer hole 228. As a result, the end plate portion (second component) 222 is positioned with high precision relative to the base (first component) 221.

[0161] The support bolt 224 is fastened to the threaded hole 227. As a result, the end plate (second component) 222 is properly fixed to the base (first component) 221.

[0162] The fixing between the base (first member) 221 and the end plate (second member) 222, which is secured by the support bolt 224, is set to a predetermined preload.

[0163] The gear portion 300 is disposed between the base plate portion 225 and the end plate portion (second member) 222. Three shaft portions 226 pass through the gear portion 300 and are connected to the end plate portion (second member) 222.

[0164] The gear section 300 includes two gears 310 and 320. Gear 310 is disposed between the base plate section 225 and gear 320. Gear 320 is disposed between the end plate section (second member) 222 and gear 310.

[0165] Gear 310 is approximately the same as gear 320 in shape and size. Gears 310 and 320 rotate within the outer cylinder 211 while meshing with the internal toothed pin 212. Thus, the center of gears 310 and 320 rotates around the main shaft F0.

[0166] The rotation phase of gear 310 deviates approximately 180° from the rotation phase of gear 320. During the period when gear 310 is engaged with half of the plurality of internal toothed pins 212 of the housing (outer cylinder portion) 210, gear 320 is engaged with the remaining half of the plurality of internal toothed pins 212. Therefore, gear portion 300 is capable of rotating housing (outer cylinder portion) 210 or gear carrier portion 220.

[0167] In this embodiment, the gear unit 300 includes two gears 310 and 320. Alternatively, more than two gears may be used as the gear unit. Moreover, as an alternative, a single gear may be used as the gear unit.

[0168] Each of the three crankshaft assemblies 400 includes a crankshaft 410, four bearings 421, 422, 423, and 424, and a transmission gear (external gear) 430. The transmission gear 430 can be a general spur gear. For the reducer 100 of this embodiment, the transmission gear 430 is not limited to a specific type.

[0169] The transmission gear 430 is directly or indirectly subjected to the driving force generated by a drive source (e.g., a motor). The reducer 100 can appropriately set the transmission path of the driving force from the drive source to the transmission gear 430 according to its operating environment and operating conditions. Therefore, this embodiment is not limited to a specific drive transmission path from the drive source to the transmission gear 430.

[0170] exist Figure 5The center represents the crankshaft axis (transmission axis) F2. The transmission axis F2 is approximately parallel to the main shaft F0. The crankshaft 410 rotates about the transmission axis F2.

[0171] The crankshaft 410 includes two journals (crankshaft journals) 411 and 412 and two eccentric portions (eccentric bodies) 413 and 414. Journals 411 and 412 extend along the transmission axis F2. The central axis of journals 411 and 412 coincides with the transmission axis F2. Eccentric portions 413 and 414 are formed between journals 411 and 412. Both eccentric portions 413 and 414 are eccentric relative to the transmission axis F2.

[0172] Journal 411 is inserted into bearing 421. Bearing 421 is disposed between journal 411 and end plate portion (second member) 222. Therefore, journal 411 is supported by end plate portion (second member) 222 and bearing 421. Journal 412 is inserted into bearing 422. Bearing 422 is disposed between journal 412 and base portion (first member) 221. Therefore, journal 412 is supported by base portion (first member) 221 and bearing 422.

[0173] In this embodiment, bearing 421 is a needle roller bearing, and a plurality of needle rollers 431 are arranged around journal 411. Bearing 422 is a needle roller bearing, and a plurality of needle rollers 432 are arranged around journal 412.

[0174] An eccentric portion 413 is inserted into a bearing 423. The bearing 423 is positioned between the eccentric portion 413 and the gear 310. An eccentric portion 414 is inserted into a bearing 424. The bearing 424 is positioned between the eccentric portion 414 and the gear 320.

[0175] In this embodiment, bearing 423 is a needle roller bearing, and a plurality of needle rollers 433 are arranged around the eccentric portion (eccentric body) 413. Bearing 424 is a needle roller bearing, and a plurality of needle rollers 434 are arranged around the eccentric portion (eccentric body) 414.

[0176] If the driving force is input to the transmission gear 430, the crankshaft 410 rotates about the transmission axis F2. As a result, the eccentric portions 413 and 414 rotate eccentrically about the transmission axis F2. The gears 310 and 320, connected to the eccentric portions 413 and 414 by means of bearings 423 and 424, oscillate within the circular space defined by the housing (outer cylinder) 210. The gears 310 and 320 mesh with the internal toothed pin 212, thus causing relative rotational motion between the housing (outer cylinder) 210 and the gear carrier 220.

[0177] For the reducer 100 of this embodiment, the bearing 421 can be configured to correspond to the bearing 1A in the first embodiment. In this case, the crankshaft axis (transmission axis) F2 corresponds to the center axis F3 in the first embodiment. In addition, the needle roller 431 corresponds to the rolling element (needle roller) 2 in the first embodiment. The journal 411 corresponds to the inner ring Ir in the first embodiment. The end plate portion (second member) 222 corresponds to the outer ring Or in the first embodiment.

[0178] Similarly, for the reducer 100, the bearing 422 can be configured to correspond to the bearing 1A in the first embodiment. In this case, the crankshaft axis (transmission axis) F2 corresponds to the center axis F3 in the first embodiment. Additionally, the needle roller 432 corresponds to the rolling element (needle roller) 2 in the first embodiment. The journal 412 corresponds to the inner ring Ir in the first embodiment. The base (first member) 221 corresponds to the outer ring Or in the first embodiment.

[0179] Similarly, for the reducer 100, the bearing 423 can be configured to correspond to the bearing 1A in the first embodiment. In this case, the needle roller 433 corresponds to the rolling element (needle roller) 2 in the first embodiment. The eccentric portion (eccentric body) 413 corresponds to the inner ring Ir in the first embodiment. The gear 310 corresponds to the outer ring Or in the first embodiment.

[0180] Similarly, for the reducer 100, the bearing 424 can be configured to correspond to the bearing 1A in the first embodiment. In this case, the needle roller 434 corresponds to the rolling element (needle roller) 2 in the first embodiment. The eccentric portion (eccentric body) 414 corresponds to the inner ring Ir in the first embodiment. The gear 320 corresponds to the outer ring Or in the first embodiment.

[0181] Furthermore, in the reducer 100 of this embodiment, the retainer 1 described above is housed in each bearing 421 to 424.

[0182] Therefore, it can achieve the same effect as the above-described implementation method.

[0183] Furthermore, in this embodiment, two main bearings 230 can be configured corresponding to the bearing 1A in the first embodiment.

[0184] The third embodiment of the retainer and bearing of the present invention will be described below based on the accompanying drawings.

[0185] Figure 6 This is a cross-sectional view along the axial direction of the retainer and bearing in this embodiment.

[0186] The difference between this embodiment and the first and second embodiments described above is that, regarding the configuration of the end face, there are instances where the same reference numerals are used for the corresponding constituent elements other than those mentioned above, and their descriptions are omitted.

[0187] For the retainer 1 in this embodiment, the end portions 1b and 1c are both disposed on the outer side of the peripheral portion 1a in the radial direction based on the central axis F3.

[0188] The end portion 1a1 of the peripheral portion 1a in the direction of the central axis F3 has a flange-shaped end portion 1b that protrudes radially outward relative to the central axis F3. In addition, the end portion 1a2 of the peripheral portion 1a in the direction of the central axis F3 has a flange-shaped end portion 1c that protrudes radially outward relative to the central axis F3.

[0189] like Figure 6 As shown, end faces 1b and 1c are designed as annular plates (annular plate shape) extending in a direction orthogonal to the central axis F3. End faces 1b and 1c have approximately the same profile shape when viewed along the central axis F3. Both end faces 1b and 1c are formed orthogonal to the side peripheral portion 1a.

[0190] End portions 1b and 1c have approximately equal outer diameters around the central axis F3. End portions 1b and 1c have approximately equal inner diameters around the central axis F3.

[0191] End faces 1b and 1c have approximately equal radial dimensions over the entire circumference of the central axis F3. The radial dimensions of end faces 1b and 1c relative to the central axis F3 are set to be larger than the radius of the needle roller (rolling element) 2 about the axis F4. The radial dimensions of end faces 1b and 1c relative to the central axis F3 may also be smaller than the radius of the needle roller (rolling element) 2 about the axis F4.

[0192] The thickness Tb of the end face 1b is set to be approximately the same along the entire circumference of the central axis F3. The thickness Tb of the end face 1b is set to be approximately the same along the entire radial length based on the central axis F3.

[0193] The thickness dimension Tc of the end face 1c is defined as being approximately the same along the entire circumference of the central axis F3 in the direction along the central axis F3. The thickness dimension Tc of the end face 1c is defined as being approximately the same along the entire radial length based on the central axis F3 in the direction along the central axis F3.

[0194] The thickness dimensions Tb of end face 1b and Tc of end face 1c are both formed to be equal. The thickness dimensions Tb of end face 1b and Tc of end face 1c are both set to be equal to the thickness dimension Ta of the peripheral portion 1a.

[0195] like Figure 6 As shown, on end face 1b, a protrusion (spur) 1d, serving as a limiting part or reinforcement, is formed at the radially outer end relative to the central axis F3 and at a position opposite to end face 1c. On end face 1c, a protrusion (spur) 1e, also serving as a limiting part or reinforcement, is formed corresponding to the protrusion (spur) 1d at the radially outer end relative to the central axis F3 and at a position opposite to end face 1b. Protrusions (spurs) 1d and 1e are formed on the opposing surfaces of end face 1b and end face 1c.

[0196] The protrusions (spurs) 1d and 1e, which serve as limiting or reinforcing parts, are formed continuously in a circular shape around the entire circumference of the central axis F3. The protrusions (spurs) 1d and 1e are formed at their outer edges as thick-walled parts that are thicker than the end faces 1b and 1c in the direction along the central axis F3, thus serving as limiting or reinforcing parts.

[0197] The protrusion (spur) 1d, which serves as a limiting or reinforcing part, is integrally formed with the end face 1b. The protrusion (spur) 1e, which serves as a limiting or reinforcing part, is integrally formed with the end face 1c.

[0198] The protrusion (spur) 1d, which serves as a limiting part or reinforcement, is provided that its radial width Td, relative to the central axis F3, is approximately the same throughout the entire circumference of the central axis F3. The protrusion (spur) 1e, which serves as a limiting part or reinforcement, is provided that its radial width Te, relative to the central axis F3, is approximately the same throughout the entire circumference of the central axis F3.

[0199] The width dimensions Td of the protrusion (spur) 1d, which serves as a limiting part or a reinforcing part, and the width dimension Te of the protrusion (spur) 1e are both formed to be equal.

[0200] The width dimension Td of the protrusion (spur) 1d, which serves as a limiting part or a reinforcing part, and the width dimension Te of the protrusion (spur) 1e are both formed to be equal to the thickness dimension Ta of the side peripheral part 1a.

[0201] The protrusion (spur) 1d, which serves as a limiting or reinforcing part, is visible from the opening space 1p when viewed radially inward with respect to the central axis F3. In other words, the protrusion (spur) 1d, which serves as a limiting or reinforcing part, protrudes towards the end face 1c of the opening space 1p relative to the end face 1p1 of the profile along the central axis F3. Specifically, the protrusion (spur) 1d protrudes towards the center of the opening space 1p relative to the end face 1p1 of the profile along the central axis F3.

[0202] The protrusion (spur) 1e, which serves as a limiting or reinforcing part, is visible from the opening space 1p when viewed radially inward from the central axis F3. In other words, the protrusion (spur) 1e, which serves as a limiting or reinforcing part, protrudes towards the center of the opening space 1p relative to the end face 1p1 of the opening space 1p, which has a rectangular outline, in the direction along the central axis F3.

[0203] In the direction along the central axis F3, the distance Tde between the protrusions (ribs) 1d and 1e is smaller than the distance Tp between a pair of parallel sides opposite each other in the contour of the opening space 1p in the direction along the central axis F3. Similarly, in the direction along the central axis F3, the distance Tde between the protrusions (ribs) 1d and 1e is set to be approximately equal to, or slightly larger than, the length T2 of the rolling element (needle roller) 2 in the direction along the central axis F3.

[0204] The difference between distance Tde and distance Tp is set to be equal over the entire length of one side extending circumferentially along the central axis F3 within the open space 1p, which is a rectangular outline.

[0205] The difference between distance Tde and length T2 is set to be equal in the circumferential direction based on the central axis F3 over the entire length of the end face 1p1, which is one side of the rectangular outline of the open space 1p.

[0206] The opposing end faces of protrusions 1d and 1e are parallel in a direction orthogonal to the central axis F3. The opposing end faces of protrusions 1d and 1e undergo surface treatments such as smoothing, flattening, and deburring. The smoothing and flattening treatments are more advanced than those applied to the end face 1p1 of the opening space 1p, thereby reducing friction between the end faces of protrusions 1d and 1e and the end faces of the needle roller 2.

[0207] The end face of the protrusion (rib) 1d and the end face of the protrusion (rib) 1e maintain the same distance Tde along the entire radial length based on the central axis F3. That is, the end face of the protrusion (rib) 1d and the end face of the protrusion (rib) 1e maintain the same distance Tde in their thickness direction.

[0208] The end faces of the protrusion (rib) 1d and the end faces of the protrusion (rib) 1e maintain the same distance Tde along the entire circumference of the central axis F3. That is, the end faces of the protrusion (rib) 1d and the end faces of the protrusion (rib) 1e maintain the same distance Tde along the circumference of the central axis F3.

[0209] The end faces of the protrusion (rib) 1d and the protrusion (rib) 1e can be positioned radially away from the central axis F3, relative to the central axis F4. Alternatively, the end faces of the protrusion (rib) 1d and the protrusion (rib) 1e can be positioned radially, relative to the central axis F3, to include the axis F4.

[0210] The retainer 1 in this embodiment includes: a circumferential portion 1a along the central axis F3; an opening space 1p having multiple portions disposed in the circumferential direction of the circumferential portion 1a, serving as a storage location for the needle rollers (rolling elements) 2; flange-shaped end portions 1b and 1c extending radially outward from the ends 1a1 and 1a2 of the circumferential portion 1a along the central axis F3; and protrusions (reinforcing portions, limiting portions) 1d and 1e protruding radially outward from the outer circumferential ends of the end portions 1b and 1c along the central axis F3 toward the center of the outline of the opening space 1p. The protrusions (reinforcing portions, limiting portions) 1d and 1e protrude toward the center of the outline of the rectangular outline of the opening space 1p relative to the edge of the rectangular outline of the opening space 1p along the central axis F3.

[0211] Next, the method for forming the retainer in this embodiment will be described.

[0212] In the method of forming the retainer 1 in this embodiment, the sheet metal is integrally formed by stamping. At this time, in the formation of the retainer 1, the side peripheral portion 1a and the end portions 1b and 1c are bent so that the radial cross section with respect to the central axis F3 is approximately U-shaped, and the ends connected in the circumferential direction with respect to the central axis F3 are formed into an annular shape.

[0213] Furthermore, at the end faces 1b and 1c, the outer peripheral ends, based on the central axis F3, are bent toward each other and approach each other, thereby forming protrusions (reinforcing portions, limiting portions) 1d and 1e.

[0214] Furthermore, the end faces of the protrusions (reinforcing parts, limiting parts) 1d and 1e are subjected to surface treatment such as deburring so as not to hinder the rotation of the needle roller (rolling element) 2 when in contact.

[0215] Thus, the retainer 1 is formed such that its radial cross-section relative to the central axis F3 becomes a C-shape that is approximately rectangular.

[0216] Furthermore, the bending steps, surface treatment steps, etc., can be set appropriately according to the ease of processing, and are not limited to the steps mentioned above.

[0217] The state of the retainer 1 and the needle roller (rolling element) 2 in this embodiment is explained.

[0218] In the case of retainer 1, the axis F4 is tilted and the needle roller (rolling element) 2 is tilted relative to the central axis F3.

[0219] In this embodiment, retainer 1 functions as a bearing. Therefore, as in the first embodiment... Figure 1 As shown, the outer ring Or is located radially outside the retainer 1 with respect to the central axis F3. Similarly, the inner ring Ir is located radially inside the retainer 1 with respect to the central axis F3.

[0220] Therefore, consider the state of the needle roller (rolling element) 2 being inclined circumferentially along the central axis F3.

[0221] In the retainer 1 of this embodiment, when the axis F4 is tilted and the needle roller (rolling element) 2 is tilted relative to the central axis F3, the protrusions (reinforcing parts, limiting parts) 1d and 1e first contact the end face of the needle roller (rolling element) 2. In this state, the needle roller (rolling element) 2 does not contact the edge end face 1p1 of the rectangular outline of the opening space 1p. Therefore, stress is not generated in the peripheral portion 1a near the outline of the opening space 1p due to the contact of the needle roller (rolling element) 2. In particular, the needle roller (rolling element) 2 does not contact the portion of the opening space 1p near the corner of the rectangular outline, and stress concentration is not generated.

[0222] Furthermore, when the needle roller (rolling element) 2 is tilted and first contacts the protrusions (reinforcing parts, limiting parts) 1d and 1e, the end faces 1b and 1c deform in such a way that the protrusions (reinforcing parts, limiting parts) 1d and 1e move away from each other in the direction of the central axis F3. That is, the end faces 1b and 1c deform in such a way that they move away from each other. At this time, each end face 1b and end face 1c deforms in such a way that the outer peripheral side where the protrusions (reinforcing parts, limiting parts) 1d and 1e are formed moves away from each other in the direction along the central axis F3. In contrast, deformation is suppressed on the inner peripheral side of the end faces 1b and 1c that is connected to the side peripheral part 1a.

[0223] This allows for the suppression of stress concentration at the peripheral portion 1a. Furthermore, by increasing the filler ratio of the needle rollers, breakage can be prevented even in the thinner and weaker peripheral portion 1a. This further extends the lifespan of the retainer 1.

[0224] In addition, in retainer 1, the following situation is taken into consideration: there is an oblique force acting, the axis F4 is not tilted, but the needle roller (rolling element) 2 moves along the central axis F3.

[0225] Thus, in the retainer 1 of this embodiment, when the axis F4 is not tilted and the needle roller (rolling element) 2 has moved along the central axis F3, the protrusions (reinforcing parts, limiting parts) 1d and 1e first contact the end faces of the needle roller (rolling element) 2. In this state, the needle roller (rolling element) 2 does not contact the end face 1p1 of the rectangular outline edge of the opening space 1p. Therefore, stress will not be generated in the peripheral portion 1a near the outline of the opening space 1p due to the contact of the needle roller (rolling element) 2.

[0226] Furthermore, when the needle roller 2 moves and first contacts the protrusion (reinforcing part, limiting part) 1d or the protrusion (reinforcing part, limiting part) 1e, the end face 1b or the end face 1c deforms such that the protrusions (reinforcing parts, limiting parts) 1d and 1e move away from each other in the direction of the central axis F3. That is, the end face 1b and the end face 1c deform away from each other. At this time, each end face 1b and the end face 1c deforms such that the outer peripheral side where the protrusions (reinforcing parts, limiting parts) 1d and the protrusions (reinforcing parts, limiting parts) 1e are formed moves away from each other in the direction along the central axis F3. In contrast, deformation is suppressed on the inner peripheral side of the end face 1b and the end face 1c that is connected to the side peripheral part 1a.

[0227] Therefore, the retainer 1 of this embodiment can suppress stress concentration at the peripheral portion 1a, prevent damage, and extend its service life. Consequently, the radius of the curve of the corner of the rectangular profile forming the opening space 1p can be reduced, and the gap between the retainer 1 and the rolling element 2 can be reduced, thereby achieving miniaturization.

[0228] Furthermore, the retainer 1 of this embodiment utilizes a simple structure that can be integrally formed by bending four strips, thereby reducing the number of forming processes and reducing the number of forming parts, thus enabling low-cost manufacturing.

[0229] In this embodiment, the same effect as that of the embodiment described above can be achieved.

[0230] Industrial availability

[0231] As a flexible application example of the present invention, a speed reducer or drive device (power transmission device) that uses a needle roller bearing can be cited.

Claims

1. A retainer for holding a plurality of needle roller bearings having cylindrical profiles with axes parallel to said central axis about a central axis, wherein, The retainer has: The side portion has a rectangular opening space around the central axis for receiving a plurality of the roller needles, and forms a cylindrical surface around the central axis. The annular plate-shaped end face is arranged radially from both ends of the side periphery in a direction along the central axis, relative to the central axis. as well as A limiting portion, which is integrally formed with respect to the end face as opposing protrusions around its entire circumference at the radial end of the end face relative to the central axis, and the limiting portion protrudes toward the end face of the needle roller in a direction along the central axis than the contour end face of the side peripheral portion that forms the contour of the opening space. The end faces are all disposed radially outward of the side circumference relative to the central axis, the axis of the needle is located radially outward of the side circumference relative to the central axis, and the limiting portion is located radially outward of the needle's axis relative to the central axis. The plurality of said needle rollers are arranged equidistantly from each other in the circumferential direction relative to the central axis. The distance between adjacent needles in the circumferential direction based on the central axis at a position equal to the pitch circle of the axis containing the needles is smaller than the distance between adjacent opening spaces in the circumferential direction based on the central axis at a position equal to the cylindrical surface of the side circumference at a radial position based on the central axis.

2. A retainer for holding a plurality of needle roller bearings having cylindrical profiles with axes parallel to said central axis about a central axis, wherein, The retainer has: The side portion has a rectangular opening space around the central axis for receiving a plurality of the roller needles, and forms a cylindrical surface around the central axis. The annular plate-shaped end face is arranged radially from both ends of the side periphery in a direction along the central axis, relative to the central axis. as well as A limiting portion, which is integrally formed with respect to the end face as opposing protrusions around its entire circumference at the radial end of the end face relative to the central axis, and the limiting portion protrudes toward the end face of the needle roller in a direction along the central axis than the contour end face of the side peripheral portion that forms the contour of the opening space. The end face protrudes radially inward from both ends of the side circumference in the direction along the central axis, the axis of the needle is located radially inward from the central axis than the side circumference, and the limiting portion is located radially inward from the central axis than the axis of the needle. The diameter of the cylindrical surface formed by the side peripheral portion is larger than the pitch circle diameter of the needle roller arrangement. The plurality of said needle rollers are arranged equidistantly from each other in the circumferential direction relative to the central axis. The distance between adjacent needles in the circumferential direction based on the central axis at a position equal to the pitch circle of the axis containing the needles is smaller than the distance between adjacent opening spaces in the circumferential direction based on the central axis at a position equal to the cylindrical surface of the side circumference at a radial position based on the central axis.

3. The retainer according to claim 1 or 2, wherein, The end face and the limiting part are integrally formed by stamping.

4. The retainer according to claim 1 or 2, wherein, The ends of the opening space, which are radially observed relative to the central axis, are separated from the ends of the needle rollers visible from the opening space along the central axis.

5. A bearing, wherein, This bearing has: The outer ring is formed in a circular shape and has an outer rolling surface facing the radially inward side; An inner ring, coaxially arranged with the outer ring, has an inner rolling surface facing outwards towards the radial direction; a plurality of needle rollers roll on the inner rolling surface and the outer rolling surface; and The retainer of claim 1 or 2, which retains a plurality of the said needle rollers.

6. A speed reducer, wherein, This reducer has the following features: The outer cylinder has internal teeth arranged circumferentially on its inner circumferential surface; An eccentric oscillating gear having external teeth that mesh with the internal teeth of the outer cylinder; A crankshaft, connected to a drive source, for oscillating the eccentric oscillating gear; and A gear carrier that supports the crankshaft and rotates relative to the outer cylinder. The crankshaft is supported on the gear carrier by the bearing as described in claim 5.

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