Retainer, rolling bearing, and rotating device

Abstract

The invention provides a cage, a rolling bearing, and a rotating device. A retainer (34) according to one embodiment of the present invention is provided with: an annular small-diameter ring (35); an annular large-diameter ring (36) disposed apart from the small-diameter ring (35) in the axial direction; and a plurality of column sections (37) which extend in the radial direction so as to connect the small-diameter ring (35) and the large-diameter ring (36), and which are arranged between the rolling elements adjacent in the circumferential direction. When the outer diameter of the small-diameter ring (35) is phi so and the inner diameter of the large-diameter ring (36) is phi bi, the outer diameter phi so and the inner diameter phi bi satisfy phi so < = phi bi.

Description

Technical Field

[0001] The present invention relates to a cage, a rolling bearing and a rotating device. Background Art

[0002] Rotating devices such as speed reducers are equipped with multiple rolling bearings. Cylindrical roller bearings are examples of rolling bearings. These bearings include an inner ring; an outer ring positioned radially outward of the inner ring; a plurality of cylindrical rollers, rolling elements, positioned circumferentially between the inner and outer rings; and a retainer that holds the cylindrical rollers. The retainer includes a pair of annular plates positioned axially on either side of each cylindrical roller; and a plurality of columns connecting the pair of annular plates. The columns are arranged at equal intervals in the circumferential direction. Cylindrical rollers are positioned in each of the plurality of grooves defined by the pair of annular plates and the columns. These retainers are sometimes molded using resin injection molding. This configuration improves retainer productivity.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2021-139455 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] However, in the above-mentioned prior art, a pair of annular plates are arranged axially, with a groove formed between them. Therefore, the mold cannot be released in a simple, axial direction of the retainer. To form the groove, a sliding core is required that slides radially during demolding. This complicates the mold structure, making it difficult to manufacture the retainer.

[0008] The present invention provides a cage, a rolling bearing, and a rotating device that can be easily manufactured.

[0009] Solutions for solving problems

[0010] A retainer according to one form of the present invention is a retainer for retaining the rolling elements of a rolling bearing having a plurality of rolling elements arranged in a circumferential direction, and comprises: an annular small-diameter ring; an annular large-diameter ring, which is arranged separately from the small-diameter ring in the axial direction; and a plurality of column portions, which extend radially in a manner connecting the small-diameter ring and the large-diameter ring, and the plurality of column portions are arranged between the rolling elements adjacent to each other in the circumferential direction, and when the outer diameter of the small-diameter ring is set to Φso and the inner diameter of the large-diameter ring is set to Φbi, the outer diameter Φso and the inner diameter Φbi satisfy Φso≤Φbi.

[0011] This structure allows the formation of a groove defined by the large-diameter ring, the small-diameter ring, and the column portion during injection molding of the retainer, even when the mold is released only in the retainer's axial direction. This simplifies the mold structure and facilitates retainer manufacture.

[0012] In the above structure, a small diameter side inclined portion may be formed at a corner located on the small diameter ring side of the column portion and radially outward of the small diameter ring, and the small diameter side inclined portion may be inclined in a manner gradually toward the radial inside as it moves axially toward the small diameter ring.

[0013] In the above structure, a large diameter side inclined portion may be formed at a corner located on the large diameter ring side of the column portion and radially inward of the large diameter ring, and the large diameter side inclined portion may be inclined gradually toward the radial outside as it moves axially toward the large diameter ring.

[0014] In the above structure, at least one of a small diameter side inclined portion and a large diameter side inclined portion may be formed on the column portion, and the small diameter side inclined portion is arranged at a corner portion located on the small diameter ring side and radially outward of the small diameter ring, and is inclined in a manner gradually toward the radial inside as it moves axially toward the small diameter ring, and the large diameter side inclined portion is arranged at a corner portion located on the large diameter ring side and radially inward of the large diameter ring, and is inclined in a manner gradually toward the radial outside as it moves axially toward the large diameter ring.

[0015] In the above structure, it may also be that an inclined convex portion is formed in at least either the small diameter side inclined portion or the large diameter side inclined portion, and the circumferential width of the inclined convex portion is smaller than the circumferential width of the small diameter side inclined portion or the large diameter side inclined portion on which the inclined convex portion is formed.

[0016] In the above configuration, the inclined projection may extend in the radial direction when viewed from the axial direction.

[0017] In the above configuration, the inclined projection may extend in a direction intersecting the radial direction when viewed from the axial direction.

[0018] In the above configuration, an end face convex portion may be formed on an outer end face in the radial direction of the column portion.

[0019] In the above configuration, the end surface convex portion may be formed such that a circumferential width thereof decreases from the small-diameter ring toward the large-diameter ring.

[0020] In the above configuration, a recessed portion may be formed on an axial end surface of at least one of the large-diameter ring and the small-diameter ring and between two of the columnar portions adjacent to each other in the circumferential direction.

[0021] In the above configuration, the recess may be formed over the entire radial direction of at least one of the large-diameter ring and the small-diameter ring.

[0022] In the above configuration, the column portion may be integrally formed with an outer column portion disposed radially outward and an inner column portion disposed radially inward, and the outer column portion and the inner column portion may be formed so as to contact the rolling element.

[0023] In the above configuration, the outer column portion and the inner column portion may be formed so that a load pressing the outer column portion by the rolling element and a load pressing the inner column portion by the rolling element are different.

[0024] In the above structure, it may also be that the outer column portion extends from the surface of the large diameter ring opposite to the small diameter ring to the small diameter ring, and the inner column portion extends from the surface of the small diameter ring opposite to the large diameter ring to the large diameter ring, and the load applied to the outer column portion or the inner column portion engaged with the one of the large diameter ring and the small diameter ring with a larger radial width is greater than the load applied to the outer column portion or the inner column portion engaged with the one of the large diameter ring and the small diameter ring with a smaller radial width.

[0025] In the above structure, the two circumferential side surfaces of the outer column portion may be formed inclinedly in such a manner that the plate thickness of the outer column portion gradually becomes thicker toward the radial outer side, and the two circumferential side surfaces of the inner column portion may be formed inclinedly in such a manner that the plate thickness of the inner column portion gradually becomes thicker toward the radial inner side.

[0026] In the above structure, it may also be that, when the rolling body is in contact with the column portion without load, a straight line passing through the center of an angle between the outer side surface of one of the two side surfaces of the outer column portion and the inner side surface of the two side surfaces of the inner column portion that is located on the same plane as the outer side surface deviates from the center axis of the rolling body.

[0027] In the above configuration, the column portion may be formed so as to contact the rolling element between the outer peripheral surface of the small-diameter ring and the inner peripheral surface of the large-diameter ring when viewed in the axial direction.

[0028] Another form of a rolling bearing of the present invention comprises: an inner ring; an outer ring, which is arranged on the radial outside of the inner ring; a plurality of rolling elements, which are arranged between the inner ring and the outer ring and arranged in the circumferential direction; and a retainer, which retains the plurality of rolling elements, the retainer comprising: an annular small-diameter ring; an annular large-diameter ring, which is arranged axially separately from the small-diameter ring; and a plurality of column portions, which extend radially in a manner connecting the small-diameter ring and the large-diameter ring and are arranged between the rolling elements adjacent to each other along the circumferential direction, and when the outer diameter of the small-diameter ring is set to Φso and the inner diameter of the large-diameter ring is set to Φbi, the outer diameter Φso and the inner diameter Φbi satisfy Φso≤Φbi.

[0029] This structure allows the formation of a groove defined by the large-diameter ring, the small-diameter ring, and the post during injection molding of the retainer, even when the mold release direction is set solely in the retainer's axial direction. This simplifies the mold structure, facilitating retainer manufacturing and, consequently, rolling bearing manufacturing.

[0030] Another embodiment of the rotating device of the present invention comprises: a housing having an internal gear; a gear frame rotatably supported by the housing; at least one crankshaft having a shaft body rotatably supported by the gear frame by means of a first rolling bearing; and an external gear meshing with the internal gear, the crankshaft having an eccentric portion eccentric with respect to the axis of rotation of the shaft body, the external gear rotatably supported by the eccentric portion by means of a second rolling bearing, the second rolling bearing comprising: an inner ring; an outer ring disposed radially outward of the inner ring ; a plurality of rolling elements arranged between the inner ring and the outer ring and arranged in the circumferential direction; and a retainer that retains the plurality of rolling elements, the retainer comprising: an annular small-diameter ring; an annular large-diameter ring arranged separately from the small-diameter ring in the axial direction; and a plurality of column portions extending in the radial direction so as to connect the small-diameter ring and the large-diameter ring, and arranged between the circumferentially adjacent rolling elements, wherein when the outer diameter of the small-diameter ring is set to Φso and the inner diameter of the large-diameter ring is set to Φbi, the outer diameter Φso and the inner diameter Φbi satisfy Φso≤Φbi.

[0031] This structure allows the formation of a groove defined by the large-diameter ring, the small-diameter ring, and the post during injection molding of the retainer, even when the mold release direction is limited to the retainer's axial direction. This simplifies the mold structure, facilitating retainer manufacture. Furthermore, the manufacturing of the rotating device is facilitated.

[0032] Effects of the Invention

[0033] The above-mentioned cage, rolling bearing, and rotating device can be easily manufactured. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a cross-sectional view of a reduction gear transmission in an embodiment of the present invention.

[0035] Figure 2 This is a perspective view of the rolling elements and the cage according to the embodiment of the present invention as viewed from the outside in the axial direction.

[0036] Figure 3 This is a perspective view of the rolling elements and the cage according to the embodiment of the present invention as viewed from the center side in the axial direction.

[0037] Figure 4 It is a cross-sectional view along the axial direction of the cage in the embodiment of the present invention.

[0038] Figure 5 This is an enlarged cross-sectional view of a column portion of an eccentric bearing in an embodiment of the present invention in a radial direction.

[0039] Figure 6 It is an explanatory diagram showing the behavior of the column part in the embodiment of the present invention.

[0040] Figure 7 It is an explanatory diagram of a method for manufacturing a cage in an embodiment of the present invention.

[0041] Figure 8 This is a side view of a column portion according to a first modified example of the embodiment of the present invention, as viewed from the axial direction.

[0042] Figure 9 This is a side view of a column portion according to a second modified example of the embodiment of the present invention, as viewed from the axial direction.

[0043] Figure 10 This is a perspective view of a portion of the cage according to the third modified example as viewed from the small-diameter ring side.

[0044] Figure 11 This is a perspective view of a portion of the cage in the third modified example as viewed from the large-diameter ring side.

[0045] Figure 12 This is a perspective view of a portion of the cage according to the fourth modified example as viewed from the small-diameter ring side.

[0046] Figure 13 This is a perspective view of a portion of the cage in the fourth modified example as viewed from the large-diameter ring side.

[0047] Figure 14 This is a perspective view of a portion of the cage according to the fifth modification as viewed from the small-diameter ring side.

[0048] Figure 15 This is a perspective view of a portion of the cage in the sixth modified example as viewed from the small-diameter ring side.

[0049] Figure 16 This is a perspective view of a portion of the cage according to the seventh modification as viewed from the small-diameter ring side.

[0050] Figure 17 This is a perspective view of a portion of the cage according to the eighth modified example as viewed from the small-diameter ring side.

[0051] Figure 18 This is a perspective view of a portion of the cage according to the ninth modification as viewed from the small-diameter ring side.

[0052] Figure 19 This is a perspective view of a portion of the cage according to the ninth modification as viewed from the large-diameter ring side.

[0053] Figure 20 This is a perspective view of the crankshaft and the eccentric bearing in the tenth modified example as viewed from the base plate side.

[0054] Figure 21 It is a partially enlarged view of a cross-sectional view along the axial direction of the large-diameter ring in the 11th modification.

[0055] Figure 22 It is a partially enlarged view of a cross-sectional view along the axial direction of the large-diameter ring in the 12th modification.

[0056] Figure 23 It is a partially enlarged view of a cross-sectional view of the cage according to the thirteenth modification along the axial direction.

[0057] Figure 24 This is a perspective view of a portion of the cage according to the fourteenth modified example as viewed from the small-diameter ring side.

[0058] Figure 25 This is a perspective view of a portion of the cage according to the fourteenth modified example as viewed from the large-diameter ring side.

[0059] Figure 26 This is a perspective view of a portion of the cage according to the fifteenth modified example as viewed from the small-diameter ring side.

[0060] Figure 27 This is a perspective view of a portion of the cage according to the fifteenth modified example as viewed from the large-diameter ring side.

[0061] Description of Reference Numerals

[0062] 1. Speed ​​reducer (rotating device); 2. Housing; 3. Gear carrier; 5. Internal gear pin (internal gear); 6. Main bearing (first rolling bearing); 13. Crankshaft (rotating body); 13a. First eccentric portion (eccentric portion); 13b. Second eccentric portion (eccentric portion); 13c. Shaft body; 15. First external gear (external gear); 16. Second external gear (external gear); 19. Eccentric portion bearing (rolling bearing, second rolling bearing); 31. Inner ring; 32. Outer ring; 33. Rolling element; 34. Cage; 35. Small diameter ring; 35a. Opposing surface (surface of the small diameter ring facing the large diameter ring); 35b. Outer peripheral surface; 36. Large diameter ring; 3 6a, opposite surface (the surface of the large-diameter ring opposite to the small-diameter ring); 36c, inner circumferential surface; 37, column portion; 44, outer column portion; 44c, side surface (outer side surface); 45, inner column portion; 45c, side surface (inner side surface); 46, inclined portion on the small-diameter side; 47, inclined portion on the large-diameter side; 51, inclined convex portion on the small-diameter side (inclined convex portion); 52, inclined convex portion on the large-diameter side (inclined convex portion); 53, end face convex portion; 53b, 53c, 54, inclined side surface; 55, inner small-diameter concave portion (concave portion); 56, inner large-diameter concave portion (concave portion); 57, outer small-diameter concave portion (concave portion); 58, outer large-diameter concave portion (concave portion); C, center axis; L, straight line. DETAILED DESCRIPTION

[0063] Next, embodiments of the present invention will be described with reference to the drawings.

[0064] <Reduction gear>

[0065] Figure 1 It is a cross-sectional view of the reduction gear 1 as a rotating device.

[0066] like Figure 1 As shown, the reduction gear 1 decelerates the rotation of, for example, an electric motor (not shown) and outputs the decelerated output. The reduction gear 1 is a so-called eccentric oscillating type reduction gear. The reduction gear 1 comprises: a cylindrical housing 2; a gear carrier 3 rotatably disposed radially inward of the housing 2; and a reduction mechanism 4 coupled to the gear carrier 3. The central axis of the housing 2 coincides with the rotational axis of the gear carrier 3.

[0067] In the following description, these center axes and rotational axes are collectively referred to as the first rotational axis A1. The direction parallel to the first rotational axis A1 is referred to as the axial direction. The direction of rotation of the gear carrier 3 is referred to as the circumferential direction. The radial direction of the housing 2, which is orthogonal to the axial and circumferential directions, is referred to simply as the radial direction.

[0068] <Housing>

[0069] An outer flange portion 2a extending radially outward is integrally formed on the outer peripheral surface of the housing 2. Multiple bolt holes 2b for inserting bolts (not shown) are formed in the outer flange portion 2a. The bolt holes 2b are arranged at equal intervals in the circumferential direction. Bolts (not shown) are inserted into the bolt holes 2b and tightened to, for example, the arm of an industrial robot, thereby securing the reduction gear 1.

[0070] The inner circumferential surface of the housing 2 is formed with a plurality of pin grooves 2c extending axially. The pin grooves 2c are arranged at equal intervals in the circumferential direction. Internally toothed pins 5 are fitted into each of the pin grooves 2c. The internally toothed pins 5 function as internal teeth that mesh with externally toothed gears 15 and 16 of the reduction gear mechanism 4, which will be discussed later.

[0071] Main bearings 6 are provided on both sides in the axial direction of the inner peripheral surface of the housing 2. The carrier 3 is rotatably supported by the housing 2 via the main bearings 6. The main bearings 6 are, for example, angular contact ball bearings.

[0072] <Gear rack>

[0073] The carrier 3 includes a disc-shaped base plate portion 7 and an end plate portion 8 that are disposed opposite to each other in the axial direction, and three column portions 9 that are formed to protrude from the base plate portion 7 toward the end plate portion 8 .

[0074] The pillars 9 are arranged at equal intervals in the circumferential direction. An end plate 8 is arranged at the top end 9a of the pillar 9. The end plate 8 is fixed to the pillar 9 by bolts 10. In this state, a space having a certain width in the axial direction is formed between the base plate 7 and the end plate 8.

[0075] A pin hole 12a is formed in the portion of the column 9 radially inward of the bolt 10. A pin 11 is inserted or press-fitted into the pin hole 12a. The pin 11 positions the end plate 8 relative to the base plate 7. The pin 11 is also inserted or press-fitted into a pin hole 12b provided in the end plate 8.

[0076] The outer peripheral surface of the base plate portion 7 and the outer peripheral surface of the end plate portion 8 are supported on the housing 2 in a rotatable manner by means of corresponding main bearings 6. Shaft insertion holes 7a and 8a are formed in the radial center of the base plate portion 7 and the radial center of the end plate portion 8, respectively. The two shaft insertion holes 7a and 8a are arranged on the same axis. In the base plate portion 7 and the end plate portion 8, three crankshaft insertion holes 7b and 8b are formed between the circumferentially adjacent column portions 9, respectively. The crankshaft insertion holes 7b and 8b are arranged on the same axis. That is, the center axis A2 of the crankshaft insertion holes 7b and 8b that are opposite to each other in the axial direction is parallel to the first rotation axis A1. A crankshaft bearing 18 is provided in each crankshaft insertion hole 7b and 8b. The crankshaft bearing 18 is, for example, a tapered roller bearing.

[0077] <Reduction Mechanism>

[0078] The reduction mechanism 4 rotates the gear carrier 3 at a speed that is reduced by a certain ratio relative to the speed of the motor shaft of an electric motor (not shown). The reduction mechanism 4 includes: three crankshafts 13 inserted into the crankshaft insertion holes 7b and 8b; a transmission spur gear 14 provided at the axial end of each crankshaft 13; and two external gears 15 and 16 (a first external gear 15 and a second external gear 16) provided between the base plate 7 and the end plate 8.

[0079] The transmission spur gear 14 meshes with a motor shaft (not shown), so that the rotation of the electric motor is transmitted to the transmission spur gear 14, causing the transmission spur gear 14 to rotate.

[0080] Each crankshaft 13 is rotatably supported on the gear carrier 3 (base plate 7 and end plate 8) by a respective crankshaft bearing 18. The crankshaft 13 includes a shaft body 13c that rotates about the central axis A2, and a first eccentric portion 13a and a second eccentric portion 13b formed in the axial center of the shaft body 13c. The shaft body 13c is rotatably supported on both sides of the axial direction by the gear carrier 3 (base plate 7 and end plate 8) by crankshaft bearings 18.

[0081] In the following description, both axial sides of the shaft body 13c are referred to as axial outer sides, and the axial center side of the shaft body 13c where the eccentric portions 13a and 13b are arranged is simply referred to as the axial center side.

[0082] The shaft body 13c is coaxially arranged and integrated with the transmission spur gear 14. That is, the crankshaft 13 and the transmission spur gear 14 rotate integrally about the central axis A2. Hereinafter, the central axis A2 will be referred to as the second rotation axis A2 of the crankshaft 13.

[0083] The first eccentric portion 13a and the second eccentric portion 13b are eccentric relative to the second rotation axis A2. The first eccentric portion 13a and the second eccentric portion 13b are arranged axially adjacent to each other between the two crankshaft bearings 18. In other words, the first eccentric portion 13a and the second eccentric portion 13b are arranged axially adjacent to each other between the base plate portion 7 and the end plate portion 8. The first eccentric portion 13a and the second eccentric portion 13b are arranged so that the phase angle is offset by 180 degrees.

[0084] Each eccentric portion 13a, 13b is provided with an eccentric bearing (an example of a bearing in the claims) 19. Details of the eccentric bearing 19 will be discussed below. Axial movement of the eccentric bearing 19 is restricted by a washer 21 provided axially outside each eccentric portion 13a, 13b. The first and second external gears 15, 16 are rotatably supported on the crankshafts 13 via the eccentric bearings 19.

[0085] The first external gear 15 and the second external gear 16 are arranged in the space between the base plate 7 and the end plate 8. The first external gear 15 and the second external gear 16 oscillate and rotate in response to the rotation of the crankshaft 13. Specifically, through-holes 15a and 16a are formed in the first external gear 15 and the second external gear 16, respectively, for receiving the eccentric bearings 19. Therefore, when the first eccentric portion 13a and the second eccentric portion 13b oscillate and rotate due to the rotation of the crankshaft 13, the first external gear 15 and the second external gear 16 oscillate and rotate via the eccentric bearings 19.

[0086] Openings 15b and 16b are formed in the first external gear 15 and the second external gear 16, respectively, to prevent interference with the column portion 9. Shaft insertion holes 15c and 16c are formed in the radial centers of the first external gear 15 and the second external gear 16, respectively. External teeth 15d and 16d are formed on the outer peripheries of the first external gear 15 and the second external gear 16, respectively. The number of teeth on each of the external teeth 15d and 16d is, for example, one less than the number of internal tooth pins 5 of the housing 2.

[0087] <Eccentric bearing>

[0088] The eccentric bearing 19 is a so-called needle roller bearing. It comprises an annular inner ring 31, integrally connected to the eccentric portions 13a and 13b of the crankshaft 13; an annular outer ring 32, integrally connected to the external gears 15 and 16; a plurality of rolling elements 33 disposed between the inner and outer rings 31 and 32; and a retainer 34, which holds the rolling elements 33. The rolling elements 33 are needle rollers arranged parallel to the axial direction. The rolling elements 33 are arranged circumferentially around the inner and outer rings 31 and 32.

[0089] Retainer

[0090] The holder 34 is formed of a resin. As the resin, for example, a nylon resin containing glass can be used. However, the present invention is not limited to this, and various resins can be used.

[0091] Figure 2 This is a perspective view of the rolling elements 33 and the cage 34 of the eccentric bearing 19 as viewed from the outside in the axial direction.

[0092] Figure 3 This is a perspective view of the rolling element 33 and the cage 34 of the eccentric bearing 19 as viewed from the center side in the axial direction.

[0093] Figure 4 It is a cross-sectional view of the retainer 34 along the axial direction.

[0094] like Figures 2 to 4As shown, the retainer 34 is integrally formed with: an annular small-diameter ring 35, which is arranged at an axially outer position than the rolling element 33; a large-diameter ring 36, which is arranged at an axially central position than the rolling element 33; and a plurality of columns 37, which connect the small-diameter ring 35 and the large-diameter ring 36.

[0095] The small-diameter ring 35 is formed along the outer circumferential surface of the inner ring 31. Specifically, the inner diameter φsi of the small-diameter ring 35 is slightly larger than the outer diameter of the inner ring 31. The axially outer outer end surface 35d of the small-diameter ring 35 contacts the washer 21. This restricts axial outward movement of the eccentric bearing 19.

[0096] The large-diameter ring 36 is formed along the inner circumference of the outer ring 32. Specifically, the outer diameter φ of the large-diameter ring 36 is slightly smaller than the inner diameter of the outer ring 32. In two axially aligned eccentric bearings 19, the outer end surfaces 36d of the axially centered sides of the respective large-diameter rings 36 contact each other. This restricts movement of the eccentric bearings 19 toward the axial center.

[0097] The outer diameter Φso of the small diameter ring 35 and the inner diameter Φbi of the large diameter ring 36 satisfy

[0098] Φso≤Φbi···(1).

[0099] The radial width Wo of the large-diameter ring 36 is larger than the radial width Ws of the small-diameter ring 35 .

[0100] Figure 5 It is a cross-sectional view showing an enlarged radial direction of the column portion 37 of the eccentric bearing 19 . Figure 5 The axial center side is viewed from the axial outside. Figure 5 In order to facilitate understanding of the description, the small-diameter ring 35 is shown in a see-through manner.

[0101] like Figures 2 to 5 As shown, the columnar portions 37 extend in the axial direction and are arranged at equal intervals in the circumferential direction. Rolling elements 33 are respectively arranged in the groove portions 41 defined by the columnar portions 37, the small diameter ring 35, and the large diameter ring 36.

[0102] The column portion 37 is integrally formed with an outer column portion 44 arranged on the outer side in the radial direction and an inner column portion 45 arranged on the inner side in the radial direction.

[0103] The outer column portion 44 extends from the surface 36a of the large-diameter ring 36 facing the small-diameter ring 35 to the small-diameter ring 35. The axially outer end portion of the outer column portion 44 (on the small-diameter ring 35 side) is joined to the outer peripheral surface 35b of the small-diameter ring 35.

[0104] The radially inner inner end surface 44a of the outer column portion 44 is located radially inward of the outer peripheral surface 35b of the small-diameter ring 35. The end portion of the outer column portion 44 on the axial center side (the large-diameter ring 36 side) extends so as to engage the inner peripheral surface 36c of the large-diameter ring 36. The radially outer outer end surface 44b of the outer column portion 44 is flush with the outer peripheral surface 36b of the large-diameter ring 36.

[0105] A small-diameter-side inclined portion 46 is formed at a corner located axially outward of the outer column portion 44 and radially outward of the small-diameter ring 35. The small-diameter-side inclined portion 46 is inclined so as to gradually move radially inward as it moves axially outward. The circumferential width of the small-diameter-side inclined portion 46 gradually increases as it moves radially outward.

[0106] The circumferential side surfaces 44c of the outer column portion 44 are inclined so that the circumferential thickness of the outer column portion 44 gradually increases radially outward. In other words, the radially oriented cross-section of the outer column portion 44 is an isosceles trapezoid. The circumferential width of the outer end surface 44b of the outer column portion 44 is greater than the circumferential width of the inner end surface 44a.

[0107] The inner column portion 45 extends from the surface 35a of the small-diameter ring 35 that faces the large-diameter ring 36 to the large-diameter ring 36. The radially outer outer end surface 45b of the inner column portion 45 is joined to the inner end surface 44a of the outer column portion 44. The radially inner inner end surface 45a of the inner column portion 45 is flush with the inner circumferential surface 35c of the small-diameter ring 35.

[0108] A large-diameter-side inclined portion 47 is formed at a corner located on the axial center side of the inner column portion 45 and radially inward of the large-diameter ring 36, and at an end portion on the axial center side of the outer column portion 44 and radially inward of the large-diameter ring 36. The large-diameter-side inclined portion 47 is inclined so as to gradually tilt radially outward as it moves toward the axial center side.

[0109] The two circumferential side surfaces 45c of the inner column portion 45 are inclined so that the circumferential plate thickness of the inner column portion 45 gradually increases as it moves radially inward. In other words, the radially cross-sectional shape of the inner column portion 45 is an isosceles trapezoid. The circumferential width of the inner end surface 45a of the inner column portion 45 is greater than the circumferential width of the outer end surface 45b.

[0110] The column portion 37 thus formed is shaped so that the junction between the outer column portion 44 and the inner column portion 45 (the region between the inner end surface 44a of the outer column portion 44 and the outer end surface 45b of the inner column portion 45) is maximally constricted. In other words, the opening area of ​​the groove portion 41 decreases radially outward and radially inward.

[0111] When the rolling element 33 is in contact with the column portion 37 without load, a straight line L passing through the center of the angle between the side surface 44 c of the outer column portion 44 and the side surface 45 c of the inner column portion 45, which is flush with the side surface 44 c, deviates from the central axis C of the rolling element 33. In other words, the straight line L is a straight line at which the angle θ1 between the straight line L and the side surface 44 c of the outer column portion 44 and the angle θ2 between the straight line L and the side surface 45 c of the inner column portion 45 are equal.

[0112] No load refers to a state in which no force is applied to press the column portion 37 against the rolling element 33. In other words, no load can be said to be a design value.

[0113] Specifically, the deviation between the straight line L and the central axis C means that the straight line L passes radially inward of the central axis C. More specifically, when the rolling element 33 is in contact with the column portion 37 without load, the rolling element 33 is in contact with the side surface 44c of the outer column portion 44 (see Figure 5 When the rolling element 33 is in contact with the column portion 37 without load, a small gap G is formed between the rolling element 33 and the side surface 45c of the inner column portion 45. The size of the small gap G is, for example, approximately 0.1 mm or less.

[0114] <Operation of the reduction gear>

[0115] Next, the operation of the reduction gear 1 will be described.

[0116] The transmission spur gear 14 and the crankshaft 13 are rotated integrally by an electric motor (not shown). Furthermore, the first external gear 15 and the second external gear 16 swing and rotate. As they swing and rotate, a portion of the external teeth 15d and 16d of each external gear 15 and 16 meshes with the internal tooth pin 5 of the housing 2. The number of teeth of each external gear 15d and 16d is, for example, one less than the number of internal tooth pins 5. Therefore, the meshing portion of each external gear 15d and 16d deviates sequentially from the internal tooth pin 5 (housing 2) in the circumferential direction, and each external gear 15 and 16 rotates. The rotation thereof is decelerated relative to the rotation of the crankshaft 13.

[0117] As the external gears 15 and 16 rotate, the crankshafts 13 also rotate around the second rotation axis A2 while revolving around the first rotation axis A1. Each crankshaft 13 is supported on the gear rack 3 (base plate portion 7, end plate portion 8) in a rotatable manner. Therefore, the gear rack 3 rotates as the crankshafts 13 revolve. As a result, the reduction gear 1 reduces the rotation of the electric motor (motor shaft) not shown in the figure and outputs it from the gear rack 3. Assuming that the gear rack 3 is fixed to the arm of an industrial robot, etc., the reduction gear 1 can reduce the rotation of the electric motor and output it from the housing 2.

[0118] Next, the function of the eccentric bearing 19 will be described.

[0119] As the crankshaft 13 and the external gears 15 and 16 rotate, the inner ring 31 (the eccentrics 13a and 13b) and outer ring 32 (the external gears 15 and 16) of the eccentric bearing 19 rotate relative to each other, thereby rotating the rolling elements 33 and the cage 34.

[0120] Each rolling element 33 is retained by a retainer 34, so that each rolling element 33 rotates while maintaining a constant spacing in the circumferential direction. The opening area of ​​the groove portion 41 in the retainer 34 decreases radially outward. Therefore, the retainer 34 prevents the rolling elements 33 from falling out of the eccentric bearings 19.

[0121] The column portion 37 is formed with a smaller-diameter inclined portion 46 and a larger-diameter inclined portion 47. This allows the column portion 37 to surround both circumferential sides of the rolling element 33 while allowing the groove portion 41 to be as wide as possible. This improves the flow of lubricating oil from the outside to the inside of the eccentric bearing 19 (hereinafter referred to as oil flow). This improved oil flow allows the rolling elements 33 and the retainer 34 to rotate smoothly between the inner ring 31 and the outer ring 32.

[0122] When the plurality of rolling elements 33 and the retainer 34 rotate, the small-diameter ring 35 contacts the washer 21, generating sliding friction resistance (for example, see Figure 2 、 Figure 3 Since the large diameter rings 36 adjacent to each other in the axial direction contact each other, sliding friction resistance is generated (for example, refer to Figure 2 、 Figure 3 Arrow F2 in the figure).

[0123] On the other hand, the rolling element 33 generates a load that presses the column 37 (hereinafter also referred to as the pressing load of the rolling element 33). This load is in the opposite direction to the direction in which the force of the sliding friction resistance is applied (see, for example, Figure 2 、 Figure 3 Arrow F3).

[0124] The outer diameter Φso of the small diameter ring 35 and the inner diameter Φbi of the large diameter ring 36 of the retainer 34 satisfy the above formula (1). The outer column portion 44 of the column portion 37 is mainly engaged with the opposing surface 36a of the large diameter ring 36. The inner column portion 45 of the column portion 37 mainly extends between the opposing surface 35a of the small diameter ring 35. As a result, a torsional load is generated at the joint between the outer peripheral surface 35b of the small diameter ring 35 and the outer column portion 44 (for example, see Figure 2 A torsional load is generated at the joint between the inner circumferential surface 36c of the large-diameter ring 36 and the outer column portion 44 (for example, see Figure 3 Arrow F5).

[0125] Figure 6 It is an explanatory diagram showing the behavior of the column portion 37 . Figure 6 With the aforementioned Figure 5 Corresponding.

[0126] However, if Figure 5 As shown, in a state where the rolling element 33 is in contact with the column portion 37 without load, the rolling element 33 is in contact with the side surface 44c of the outer column portion 44. Therefore, first, a pressing load of the rolling element 33 is generated on the outer column portion 44 (see Figure 5 Arrow F6).

[0127] So, if Figure 6 As shown, the column portion 37 is slightly elastically deformed, and the rolling element 33 contacts the side surface 44c of the outer column portion 44, and at the same time, the rolling element 33 contacts the side surface 45c of the inner column portion 45 (see Figure 6 Thus, the pressing load of the rolling element 33 is dispersed to the outer column portion 44 and the inner column portion 45 (see Figure 6 Arrow F6' and arrow F7 in FIG.

[0128] In this manner, the column portion 37 is formed so that the rolling elements 33 contact the outer column portion 44 and the inner column portion 45. By distributing the compressive load of the rolling elements 33 to the outer column portion 44 and the inner column portion 45, the respective torsional loads (arrows F4 and F5) are reduced. In other words, the compressive load of the rolling elements 33 that generates the respective torsional loads is reduced.

[0129] Specifically, for example, a load applied to the outer column portion 44 results in a torsional load primarily applied to the joint between the outer circumferential surface 35b of the small-diameter ring 35 and the outer column portion 44. For example, a load applied to the inner column portion 45 results in a torsional load primarily applied to the joint between the inner circumferential surface 36c of the large-diameter ring 36 and the outer column portion 44. This prevents the pressing load of the rolling elements 33 on the column portion 37 from being concentrated in a single location and instead distributes the loads that generate various torsional loads (arrows F4 and F5). Consequently, each torsional load is reduced.

[0130] Furthermore, the pressing load of the rolling element 33 on the outer column portion 44 with which the rolling element 33 first contacts is greater than the pressing load of the rolling element 33 on the inner column portion 45 with which the rolling element 33 contacts after the column portion 37 is elastically deformed.

[0131] <Method for manufacturing a retainer>

[0132] Then, based on Figure 7 A method for manufacturing the retainer 34 will be described.

[0133] Figure 7 It is an explanatory diagram of a method for manufacturing the retainer 34 .

[0134] like Figure 7As shown, retainer 34 is injection molded using mold 90. Mold 90 is composed of a first mold 91 and a second mold 92 that are separated from each other in the axial direction of retainer 34. First mold 91 follows the outer circumferential surface 35b of small-diameter ring 35. Second mold 92 follows the inner circumferential surface 36c of large-diameter ring 36.

[0135] The outer diameter Φso of the small-diameter ring 35 and the inner diameter Φbi of the large-diameter ring 36 satisfy the above-mentioned formula (1). Therefore, even when the mold is released in the axial direction, the first mold 91 and the second mold 92 can be overlapped in the radial direction between the small-diameter ring 35 and the large-diameter ring 36. This allows the groove portion 41 of the retainer 34 to be formed without providing a so-called sliding core. A sliding core is a mold that slides in a direction intersecting the axial direction.

[0136] Therefore, according to the above-described retainer 34 , since the resin is injection-molded, the retainer 34 can be easily formed.

[0137] When the retainer 34 is injection molded, only the mold release along the axial direction can be utilized (see Figure 7 (Indicated by the arrow in the figure) The two molds 91 and 92 are formed with grooves 41. Therefore, the structure of the mold 90 can be simplified, and the retainer 34 can be easily manufactured. In turn, the eccentric bearing 19 can be easily manufactured, and the reduction gear 1 can be easily manufactured.

[0138] The column portion 37 of the retainer 34 is formed with a small-diameter inclined portion 46 and a large-diameter inclined portion 47. Therefore, the small-diameter inclined portion 46 and the large-diameter inclined portion 47 allow the groove portion 41 to be opened as wide as possible. Consequently, even when the column portion 37 surrounds both circumferential sides of the rolling element 33, oil flow can be improved.

[0139] The column portion 37 is integrally formed with an outer column portion 44 and an inner column portion 45. The column portion 37 is formed so that the rolling elements 33 contact the columns 44 and 45 when the reduction gear 1 is driven. Therefore, the overall load applied to the column portion 37 can be distributed between the outer column portion 44 and the inner column portion 45. As a result, the torsional load primarily applied to the joint between the outer circumferential surface 35b of the small-diameter ring 35 and the outer column portion 44, and the torsional load primarily applied to the joint between the inner circumferential surface 36c of the large-diameter ring 36 and the outer column portion 44, can be reduced. Consequently, the rigidity of the retainer 34 can be improved.

[0140] Of the pressing loads on the rolling elements 33, the pressing load applied to the outer column portions 44 is greater than the pressing load applied to the inner column portions 45, with which the rolling elements 33 come into contact after the column portions 37 have elastically deformed. This makes the pressing loads on the rolling elements 33 on the outer column portions 44 and the pressing loads on the inner column portions 45 different. By adjusting the pressing loads on the rolling elements 33 applied to the respective column portions 44 and 45, the rigidity of the retainer 34 can be increased.

[0141] In particular, the radial width Wo of the large-diameter ring 36, to which the outer column portion 44 is joined, is larger than the radial width Ws of the small-diameter ring 35. This also allows the joint between the large-diameter ring 36 and the outer column portion 44 to be as large as possible. This increases the rigidity of the outer column portion 44 relative to the rigidity of the inner column portion 45. The compressive load applied to the rolling elements 33 of the relatively rigid outer column portion 44 can be increased compared to the compressive load applied to the rolling elements 33 of the relatively rigid inner column portion 45. Consequently, the load resistance of the retainer 34 as a whole can be improved. Consequently, the rigidity of the retainer 34 can be further increased.

[0142] To differentiate the pressing loads applied to the rolling elements 33 on the outer column 44 from the pressing loads applied to the inner column 45, the timing of contact between the rolling elements 33 and the outer column 44 is slightly different from the timing of contact between the rolling elements 33 and the inner column 45. To achieve this difference in contact timing, a small gap is formed between the rolling elements 33 and the side surfaces 45c of the inner column 45 when the rolling elements 33 are in unloaded contact with the column 37. To create this small gap, a straight line L passing through the center of the angle between the side surfaces 44c and 45c of the column 37 is offset from the central axis C of the rolling elements 33 when the rolling elements 33 are in unloaded contact with the column 37. This configuration makes it possible to easily and reliably differentiate the pressing loads applied to the rolling elements 33 on the outer column 44 from the pressing loads applied to the inner column 45.

[0143] The circumferential side surfaces 44c of the outer column portion 44 are inclined so that the circumferential thickness of the outer column portion 44 gradually increases as it moves radially outward. The circumferential side surfaces 45c of the inner column portion 45 are inclined so that the circumferential thickness of the inner column portion 45 gradually increases as it moves radially inward. Consequently, the opening area of ​​the groove portion 41 in the retainer 34 can be reduced radially outward and radially inward. Consequently, the rolling elements 33 can be prevented from escaping the retainer 34 with a simple structure.

[0144] In the above embodiment, a case is described in which a small gap is formed between the rolling element 33 and the side surface 45c of the inner column portion 45 when the rolling element 33 is in contact with the column portion 37 of the retainer 34 without load. However, this is not limiting, and the column portion 37 may be formed as follows.

[0145] [First Modification]

[0146] Figure 8 This is a side view of the column portion 37 in the first modification example as viewed from the axial direction. Figure 8 With the aforementioned Figure 5 Corresponding. Figure 8 In order to make the description easier to understand, the small-diameter ring 35 is shown in perspective. Hereinafter, the same reference numerals as those in the above-mentioned embodiment will be given for description. The same also applies to the following second modified example.

[0147] like Figure 8 As shown, the column portion 37 may also be formed in the following manner: when the rolling body 33 is in contact with the column portion 37 without load, a straight line L passing through the center of the angle between the side surface 44c of the outer column portion 44 and the side surface 45c of the inner column portion 45 which is located on the same plane as the side surface 44c passes through the center axis C of the rolling body 33.

[0148] By configuring in this manner, the rolling element 33 can be reliably brought into contact with the side surface 44c of the outer column portion 44 and the side surface 45c of the inner column portion 45 (see FIG. Figure 8 (see points P1 and P2 in the figure). Therefore, the overall load applied to column portion 37 can be reliably distributed to outer column portion 44 and inner column portion 45. As a result, the torsional load primarily applied to the joint between outer circumferential surface 35b of small-diameter ring 35 and outer column portion 44, and the torsional load primarily applied to the joint between inner circumferential surface 36c of large-diameter ring 36 and outer column portion 44, can be reliably reduced. Consequently, the rigidity of retainer 34 can be improved.

[0149] [Second Modification]

[0150] Figure 9 This is a side view of the column portion 37 in the second modified example as viewed from the axial direction.

[0151] like Figure 9 As shown, the column portion 37 is formed as follows (see Figure 9 Point P3 in FIG: When there is no load, the rolling element 33 is in contact with the outer peripheral surface 35b of the small diameter ring 35 of the column portion 37 and the inner peripheral surface 36c of the large diameter ring 36 as viewed from the axial direction.

[0152] The torsional load is mainly generated at the joint between the outer peripheral surface 35b of the small diameter ring 35 and the outer column portion 44 (for example, see Figure 2The torsional load is mainly generated at the joint between the inner circumferential surface 36c of the large diameter ring 36 and the outer column portion 44 (for example, see Figure 3 (see arrow F5 in the figure). Therefore, when viewed axially, rolling elements 33 are in contact between the outer circumferential surface 35b of the small-diameter ring 35 and the inner circumferential surface 36c of the large-diameter ring 36 of column portion 37. Consequently, when a load is applied to outer column portion 44 and inner column portion 45, the torque applied to small-diameter ring 35 and large-diameter ring 36 can be minimized. This reduces the torsional force accordingly, ensuring the rigidity of retainer 34.

[0153] [Third Modification]

[0154] Figure 10 This is a perspective view of a portion of the retainer 34 in the third modified example as viewed from the small-diameter ring 35 side. Figure 11 This is a perspective view of a portion of the cage 34 in the third modified example as viewed from the large-diameter ring 36 side.

[0155] like Figure 10 、 Figure 11 As shown, in the column portion 37 of the third modified example, a small-diameter-side inclined convex portion 51 is formed on the small-diameter-side inclined portion 46 , and a large-diameter-side inclined convex portion 52 is formed on the large-diameter-side inclined portion 47 .

[0156] The small-diameter-side inclined protrusion 51 extends over the entire radial direction of the small-diameter-side inclined portion 46. The small-diameter-side inclined protrusion 51 extends radially when viewed from the axial direction. The small-diameter-side inclined protrusion 51 is formed so that its cross-section along the circumferential and axial directions is triangular. In other words, the small-diameter-side inclined protrusion 51 is formed so that its circumferential width gradually decreases as it moves radially outward.

[0157] The circumferential width W1 of the base of the small-diameter-side inclined protrusion 51 (hereinafter referred to as the width W1 of the small-diameter-side inclined protrusion 51) is smaller than the circumferential width W2 of the small-diameter-side inclined portion 46. This size relationship is the same across the entire radial direction of the small-diameter-side inclined protrusion 51 and the small-diameter-side inclined portion 46. The width W1 of the small-diameter-side inclined protrusion 51 gradually increases toward the radially outer side in a manner corresponding to the shape of the small-diameter-side inclined portion 46.

[0158] The large-diameter-side inclined protrusion 52 extends over the entire radial direction of the large-diameter-side inclined portion 47. The large-diameter-side inclined protrusion 52 extends radially as viewed from the axial direction. The basic structure of the large-diameter-side inclined protrusion 52 is the same as that of the small-diameter-side inclined protrusion 51. Specifically, the large-diameter-side inclined protrusion 52 is formed so that its circumferential width gradually decreases as it moves radially outward.

[0159] The circumferential width W3 of the base of the large-diameter inclined protrusion 52 (hereinafter referred to as the width W3 of the large-diameter inclined protrusion 52) is smaller than the circumferential width W4 of the large-diameter inclined portion 47. This size relationship is the same throughout the radial direction of the large-diameter inclined protrusion 52 and the large-diameter inclined portion 47.

[0160] With this structure, the lubricating oil that has entered the interior of the eccentric bearing 19 can be stirred by the small-diameter inclined protrusions 51 and the large-diameter inclined protrusions 52. More specifically, as the retainer 34 rotates, the lubricating oil inside the eccentric bearing 19 is scattered by the small-diameter inclined protrusions 51 and the large-diameter inclined protrusions 52. As the lubricating oil is scattered, new lubricating oil enters the interior of the eccentric bearing 19 from the outside.

[0161] Therefore, according to the third modified example described above, lubrication of the lubricating oil in the eccentric portion bearing 19 can be promoted by the small-diameter-side inclined convex portion 51 and the large-diameter-side inclined convex portion 52 .

[0162] Furthermore, the width W1 of the small-diameter inclined protrusion 51 is smaller than the circumferential width W2 of the small-diameter inclined portion 46. The width W3 of the large-diameter inclined protrusion 52 is smaller than the circumferential width W4 of the large-diameter inclined portion 47. This reduces the flow resistance of the lubricating oil toward the small-diameter inclined protrusion 51 and the large-diameter inclined protrusion 52. Consequently, the small-diameter inclined protrusion 51 and the large-diameter inclined protrusion 52 facilitate the dispersion of the lubricating oil.

[0163] The smaller and larger diameter convex portions 51, 52 are tapered so that their circumferential width gradually decreases as they move radially outward. Therefore, when lubricating oil is dispersed from the smaller and larger diameter convex portions 51, 52, the resistance to the lubricating oil peeling off the smaller and larger diameter convex portions 51, 52 is minimized. As a result, the smaller and larger diameter convex portions 51, 52 can effectively disperse the lubricating oil.

[0164] [Fourth Modification]

[0165] Figure 12 This is a perspective view of a portion of the retainer 34 in the fourth modified example as viewed from the small-diameter ring 35 side. Figure 13 This is a perspective view of a portion of the retainer 34 in the fourth modified example as viewed from the large-diameter ring 36 side.

[0166] In the third modification described above, the case where the small-diameter-side inclined convex portion 51 extends radially when viewed from the axial direction has been described, and the case where the large-diameter-side inclined convex portion 52 extends radially when viewed from the axial direction has been described.

[0167] However, it is not limited to this. Figure 12 、 Figure 13As shown, the small-diameter-side inclined convex portion 51 and the large-diameter-side inclined convex portion 52 may extend in a direction intersecting the radial direction when viewed from the axial direction.

[0168] More specifically, the small-diameter-side inclined convex portion 51 extends along a diagonal line of the small-diameter-side inclined portion 46 , and the large-diameter-side inclined convex portion 52 extends along a diagonal line of the large-diameter-side inclined portion 47 .

[0169] Based on such a structure, when the retainer 34 rotates, a radial force component acts on the lubricating oil squeezed out by the small-diameter side inclined convex portion 51 and the large-diameter side inclined convex portion 52 (see, for example, Figure 12 Arrow F8, Figure 13 As shown by arrow F9 in FIG. , a radial flow of the lubricating oil is generated. Accordingly, in addition to the same effects as those of the third modification described above, stirring of the lubricating oil by the small-diameter side inclined convex portion 51 and the large-diameter side inclined convex portion 52 can be further promoted.

[0170] In the third and fourth modifications described above, the case where the small-diameter-side inclined protrusion 51 is formed on the small-diameter-side inclined portion 46, and the large-diameter-side inclined protrusion 52 is formed on the large-diameter-side inclined portion 47 is described. However, this is not limiting, and at least one of the small-diameter-side inclined protrusion 51 and the large-diameter-side inclined protrusion 52 may be formed on the retainer 34.

[0171] In the third and fourth modifications described above, the smaller-diameter-side inclined protrusions 51 and the larger-diameter-side inclined protrusions 52 are formed to have triangular cross-sections along the circumferential and axial directions. However, this is not limiting. At least the width W1 of the smaller-diameter-side inclined protrusions 51 may be smaller than the circumferential width W2 of the smaller-diameter-side inclined portion 46. The width W3 of the larger-diameter-side inclined protrusions 52 may be smaller than the circumferential width W4 of the larger-diameter-side inclined portion 47.

[0172] It is desirable that each protrusion 51, 52 be formed so as to taper in a manner that its circumferential width gradually decreases radially outward. In this case, the shape of each protrusion 51, 52 is not limited to a triangular shape in cross-section along the circumferential and axial directions. For example, each protrusion 51, 52 may also be semicircular.

[0173] In the third and fourth modified examples described above, each projection 51, 52 extends over the entire radial direction of the corresponding inclined portion 46, 47. However, the present invention is not limited thereto, and each projection 51, 52 may be formed only over a portion of the entire radial direction of each inclined portion 46, 47.

[0174] [Fifth Modification]

[0175] Figure 14This is a perspective view of a portion of the retainer 34 in the fifth modification example as viewed from the small-diameter ring 35 side.

[0176] like Figure 14 As shown, in the column portion 37 of the fifth modified example, an end surface convex portion 53 is formed on the outer end surface 44 b of the outer column portion 44 .

[0177] The end face convex portion 53 extends over the entire axial direction of the outer end face 44 b and is formed to be tapered so that the circumferential width thereof decreases from the small diameter ring 35 toward the large diameter ring 36 .

[0178] More specifically, the end face protrusion 53 has a parallel side surface 53a formed as one of its two circumferential side surfaces and along the side surface 44c of the outer column portion 44. The end face protrusion 53 has an inclined side surface 53b formed as the other of its two circumferential side surfaces and inclined relative to the side surface 44c of the outer column portion 44. The end face protrusions 53 are arranged in the circumferential direction so that the parallel side surface 53a and the inclined side surface 53b have different circumferential orientations.

[0179] With this structure, the lubricating oil that has entered the interior of the eccentric bearing 19 can be stirred by the end face protrusions 53. More specifically, as the retainer 34 rotates, the lubricating oil inside the eccentric bearing 19 is scattered by the end face protrusions 53. As the lubricating oil is scattered, new lubricating oil enters the interior of the eccentric bearing 19 from the outside. Therefore, according to the above-mentioned fifth modified example, the same effect as the effect of the above-mentioned third modified example is achieved.

[0180] The end face projection 53 has an inclined side surface 53b that is inclined relative to the side surface 44c of the outer column portion 44. Therefore, when the retainer 34 rotates, an axial force component acts on the lubricating oil squeezed out by the end face projection 53. This provides the same effects as those of the fourth modified example described above.

[0181] Furthermore, each end face protrusion 53 is arranged circumferentially so that the parallel side surfaces 53a and the inclined side surfaces 53b have different circumferential orientations. Therefore, regardless of the rotational direction of retainer 34, any inclined side surface 53b in any end face protrusion 53 generates an axial flow of lubricating oil. This reliably promotes agitation of the lubricating oil.

[0182] [Sixth Modification]

[0183] Figure 15 It is a perspective view of a portion of the retainer 34 in the sixth modification as viewed from the small-diameter ring 35 side.

[0184] In the fifth modification described above, the case where the end face convex portion 53 has parallel side surfaces 53a and inclined side surfaces 53b is described. However, this is not limited to this. Figure 15As shown, the end face protrusion 53 may also be formed into an isosceles triangle shape when viewed from the radial direction. That is, the end face protrusion 53 in the sixth modification has a pair of inclined side surfaces 53 c formed on both side surfaces in the circumferential direction and inclined relative to the side surface 44 c of the outer column portion 44.

[0185] Therefore, according to the above-mentioned sixth modification, the same effect as the above-mentioned fifth modification is achieved.

[0186] [7th Modification]

[0187] Figure 16 This is a perspective view of a portion of the retainer 34 according to the seventh modification as viewed from the small-diameter ring 35 side.

[0188] The difference between the fifth modification and the seventh modification is that the shape of the inclined side surface 53 b of the fifth modification is different from the shape of the inclined side surface 54 of the seventh modification.

[0189] More specifically, the inclined side surface 54 of the seventh modification has two inclined side surfaces 54a and 54b (a first inclined side surface 54a and a second inclined side surface 54b) having different inclination angles. Of the two inclined side surfaces 54a and 54b, the first inclined side surface 54a is positioned on the side of the small-diameter ring 35. Of the two inclined side surfaces 54a and 54b, the second inclined side surface 54b is positioned between the first inclined side surface 54a and the end of the outer end surface 44b on the side of the large-diameter ring 36.

[0190] The inclination angle θ3 of the first inclined side surface 54a relative to the side surface 44c of the outer column portion 44 is larger than the inclination angle θ4 of the second inclined side surface 54b relative to the side surface 44c of the outer column portion 44. On the outer end surface 44b, the area where the second inclined side surface 54b is formed is wider than the area where the first inclined side surface 54a is formed.

[0191] Therefore, the seventh modification achieves the same effects as the fifth modification. Furthermore, the inclined side surface 54 of the seventh modification includes two inclined side surfaces 54a and 54b with different inclination angles. This facilitates the collection of a larger amount of lubricating oil by the first inclined side surface 54a. The lubricating oil collected by the first inclined side surface 54a can be directed axially by the second inclined side surface 54b. Consequently, the lubricating oil can be more efficiently agitated.

[0192] In the above-mentioned fifth to seventh modified examples, the case where the end face protrusion 53 extends over the entire axial direction of the outer end face 44b is described. The case where the end face protrusion 53 is formed so as to be tapered as the circumferential width decreases from the small-diameter ring 35 toward the large-diameter ring 36 is described. However, the shape of the end face protrusion 53 is not limited to the above-mentioned shape. The end face protrusion 53 may also be formed in a part of the entire axial direction of the outer end face 44b. The end face protrusion 53 may also be formed in a rod-like shape with a uniform circumferential width when viewed from the radial direction. The end face protrusion 53 may also be formed so as to be tapered as the circumferential width gradually decreases as it moves radially outward.

[0193] [Variation 8]

[0194] Figure 17 It is a perspective view of a portion of the retainer 34 in the eighth modification as viewed from the small-diameter ring 35 side.

[0195] like Figure 17 As shown, a plurality of inner small-diameter recesses 55 are formed on the facing surface 35a of the small-diameter ring 35 of the eighth modified example. A plurality of inner large-diameter recesses 56 are formed on the facing surface 36a of the large-diameter ring 36.

[0196] Each recess 55, 56 is disposed at the circumferential center between two circumferentially adjacent pillars 37. Therefore, each inner small-diameter recess 55 is spaced away from the connection (corner R) between the small-diameter ring 35 and the pillar 37. Each inner large-diameter recess 56 is spaced away from the connection (corner R) between the large-diameter ring 36 and the pillar 37.

[0197] Each recess 55, 56 is formed so that its cross-section along the circumferential direction forms a U-shape. Each recess 55, 56 is formed over the entire radial direction of the corresponding ring 35, 36. In other words, the inner small-diameter recess 55 communicates with both radial edges of the small-diameter ring 35. The inner large-diameter recess 56 communicates with both radial edges of the large-diameter ring 36.

[0198] Therefore, according to the eighth modification, the flow of lubricating oil within the groove portion 41 can be promoted by the recesses 55 and 56. Furthermore, the recesses 55 and 56 are formed over the entire radial direction of the corresponding ring 35 and 36. Therefore, the recesses 55 and 56 allow the lubricating oil to flow smoothly inward and outward in the radial direction of each ring 35 and 36. Consequently, lubrication of the lubricating oil at the eccentric bearing 19 can be promoted.

[0199] [9th Modification]

[0200] Figure 18 This is a perspective view of a portion of the retainer 34 according to the ninth modification as viewed from the small-diameter ring 35 side. Figure 19 This is a perspective view of a portion of the cage 34 according to the ninth modification as viewed from the large-diameter ring 36 side.

[0201] In the eighth modification, the case where a plurality of inner small diameter recesses 55 are formed on the facing surface 35a of the small diameter ring 35 has been described. The case where a plurality of inner large diameter recesses 56 are formed on the facing surface 36a of the large diameter ring 36 has been described. However, the present invention is not limited thereto. In addition to the inner small diameter recesses 55, other recesses may be formed. Figure 18 As shown in FIG. 35 , a plurality of outer small diameter recesses 57 are formed on the outer end surface 35d of the small diameter ring 35. In addition to the inner large diameter recess 56, a plurality of outer small diameter recesses 57 may also be formed as shown in FIG. Figure 19 As shown, a plurality of outer large-diameter recesses 58 are formed on the outer end surface 36 d of the large-diameter ring 36 .

[0202] Two outer small-diameter recesses 57 are arranged between each of two circumferentially adjacent pillars 37. In other words, two outer small-diameter recesses 57 are arranged between two circumferentially adjacent pillars 37, and are positioned on both sides of the inner small-diameter recess 55 when viewed in the axial direction. In other words, the inner small-diameter recesses 55 and the outer small-diameter recesses 57 are arranged alternately.

[0203] The outer large-diameter recesses 58 are also arranged in the same manner as the outer small-diameter recesses 57. Specifically, two outer large-diameter recesses 58 are arranged between each of two circumferentially adjacent columnar portions 37. In other words, the two outer large-diameter recesses 58 are arranged between two circumferentially adjacent columnar portions 37 and on both sides of the inner large-diameter recess 56 when viewed in the axial direction.

[0204] The outer small-diameter recess 57 and the outer large-diameter recess 58 are formed so that their cross-sections along the circumferential direction form a U-shape. The outer small-diameter recess 57 and the outer large-diameter recess 58 are formed over the entire radial direction of the corresponding rings 35 and 36, respectively. In other words, the outer small-diameter recess 57 communicates with both radial edges of the small-diameter ring 35. The outer large-diameter recess 58 communicates with both radial edges of the large-diameter ring 36.

[0205] Therefore, according to the above-mentioned ninth modification, in addition to the effects similar to those of the above-mentioned eighth modification, lubrication of the lubricating oil in the eccentric portion bearing 19 can be further promoted.

[0206] In the eighth and ninth modifications described above, each recessed portion 55-58 is described as being formed so that its cross-section along the circumferential direction is U-shaped. However, this is not limiting, and each recessed portion 55-58 can be formed in a variety of shapes. For example, each recessed portion 55-58 can be formed so that its cross-section along the circumferential direction is V-shaped. However, it is desirable that each recessed portion 55-58 be formed over the entire radial direction of the corresponding ring 35, 36.

[0207] In the eighth modification described above, an inner small-diameter recess 55 is formed in the small-diameter ring 35, and an inner large-diameter recess 56 is formed in the large-diameter ring 36. In the ninth modification described above, in addition to the inner small-diameter recess 55 and the inner large-diameter recess 56, an outer small-diameter recess 57 is formed in the small-diameter ring 35, and an outer large-diameter recess 58 is formed in the large-diameter ring 36. However, this is not limiting; at least one of the recesses 55 to 58 may be formed in either the small-diameter ring 35 or the large-diameter ring 36. Even with this configuration, lubrication of the lubricating oil in the eccentric bearing 19 can be promoted.

[0208] [10th Modification]

[0209] Figure 20 This is a perspective view of the crankshaft 13 and the eccentric bearing 19 in the tenth modified example as viewed from the base plate 7 side. Figure 20 In order to facilitate the understanding of the description, the crankshaft bearing 18 on the base plate portion 7 side is removed and shown.

[0210] As described above, retainer 34 is injection molded using mold 90. At this time, an ejector pin (not shown) is used to remove retainer 34 molded from mold 90. Retainer 34 is removed from mold 90 by protruding it in the direction of release from mold 90 using the ejector pin.

[0211] like Figure 20 As shown, multiple ejector pin marks M are formed on retainer 34 due to the ejector pins protruding. Each ejector pin mark M is formed at equal intervals in the circumferential direction on the outer end surface 35d of the small-diameter ring 35. In other words, the ejector pin marks M are formed on the surface (outer end surface 35d of the small-diameter ring 35) opposite the axially adjacent surface of retainer 34 (outer end surface 36d of the large-diameter ring 36). No ejector pin marks M are formed on the outer end surface 36d of the large-diameter ring 36.

[0212] However, as the reduction gear 1 is driven, the outer end surfaces 36d of the large-diameter rings 36 of axially adjacent retainers 34 rub against each other. If ejector marks M are formed on these surfaces, there is a possibility that the burrs generated by the ejector marks M will damage the retainers 34. There is also the possibility that the burrs may become foreign matter and remain within the reduction gear 1.

[0213] On the other hand, the outer end surface 35d of the small diameter ring 35 contacts only the washer 21. The friction between the washer 21 and the outer end surface 35d of the small diameter ring 35 is sufficiently smaller than the friction between the outer end surfaces 36d of the large diameter ring 36.

[0214] Therefore, according to the tenth modification, in addition to achieving the same effects as those of the aforementioned embodiment, damage to the retainer 34 can be prevented, and entry of foreign matter into the reduction gear 1 can be prevented.

[0215] In the tenth modified example described above, injection molding is performed so that ejector marks M are formed on the outer end surface 35d of the small-diameter ring 35. However, this is not limiting; the location where ejector marks M are formed may be modified depending on the mounting orientation of the retainer 34. In other words, injection molding is performed so that ejector marks M are formed on the side opposite to the side on which the surfaces of axially adjacent retainers 34 face each other. More specifically, when axially adjacent retainers 34 are mounted with their small-diameter rings 35 facing each other, the retainers 34 are injection molded so that ejector marks M are formed on the outer end surface 36d of the large-diameter ring 36.

[0216] [11th Modification]

[0217] Figure 21 It is a partially enlarged view of a cross-sectional view of the large-diameter ring 36 along the axial direction in the eleventh modified example. Figure 21 and Figure 1 Corresponding to the enlarged view of Part XXI.

[0218] like Figure 21 As shown, in the large-diameter ring 36 of the retainer 34 , rounded chamfered portions 36 e are formed on the outer peripheral edge and the inner peripheral edge of the outer end surface 36 d .

[0219] As previously described, the outer end surfaces 36d of the large-diameter rings 36 of axially adjacent retainers 34 rub against each other as the reduction gear 1 is driven. If the outer and inner circumferences of the outer end surfaces 36d are tapered, there is a risk that the circumferences of the large-diameter rings 36 may become caught, causing damage to the retainers 34.

[0220] However, by forming the rounded chamfered portions 36 e on the outer and inner circumferential edges of the outer end surface 36 d , the circumferential edges of the large-diameter rings 36 can be brought into smooth contact with each other, thereby preventing the retainers 34 from being damaged.

[0221] [12th Modification]

[0222] Figure 22 It is a partially enlarged view of a cross-sectional view of the large-diameter ring 36 along the axial direction in the twelfth modification. Figure 22 With the aforementioned Figure 21 Corresponding.

[0223] In the aforementioned 11th modification, the case where the rounded chamfered portions 36e are formed on the outer periphery and the inner periphery of the outer end surface 36d of the large diameter ring 36 is described. However, this is not limited to this. Figure 22As shown, the entire outer end surface 36d may be curved so as to be convex toward the large-diameter rings 36. Even in such a configuration, the same effects as those of the eleventh modified example described above are achieved.

[0224] In the eleventh modified example described above, rounded chamfered portions 36e are formed on both the outer and inner peripheries of the outer end surface 36d of the large-diameter ring 36. In the twelfth modified example described above, the entire outer end surface 36d of the large-diameter ring 36 is curved. However, this is not limiting; the location where the rounded chamfered portions 36e are formed or where the curve is formed may be modified depending on the mounting orientation of the retainer 34.

[0225] In other words, the surfaces of axially adjacent retainers 34 facing each other may be bent or chamfered. More specifically, when axially adjacent retainers 34 are mounted with the small-diameter ring 35 facing each other, chamfered surfaces may be formed on the outer and inner circumferences of the outer end surface 35d of the small-diameter ring 35. Alternatively, the entire outer end surface 35d of the small-diameter ring 35 may be bent.

[0226] [13th Modification]

[0227] Figure 23 It is a partially enlarged view of a cross-sectional view of the retainer 34 along the axial direction in the thirteenth modification. Figure 23 and Figure 1 Corresponding to the enlarged view of Section XXIII.

[0228] like Figure 23 As shown, the axial thickness T1 of the large-diameter ring 36 (hereinafter referred to as thickness T1) is formed thicker than the axial thickness T2 of the small-diameter ring 35 (hereinafter referred to as thickness T2). Therefore, the rigidity of the large-diameter ring 36 relative to the small-diameter ring 35 can be increased without changing the axial length of the retainer 34.

[0229] However, as previously mentioned, the outer end surfaces 36d of the large-diameter rings 36 of axially adjacent retainers 34 rub against each other as the reduction gear 1 is driven. This applies a load to the large-diameter rings 36, potentially deforming or damaging them. By increasing the rigidity of the large-diameter rings 36, which rub against each other, compared to the small-diameter rings 35, deformation and damage to the large-diameter rings 36 can be suppressed.

[0230] In the thirteenth modified example described above, the thickness T1 of the large-diameter ring 36 is formed thicker than the thickness T2 of the small-diameter ring 35. However, this is not limiting, and the thickness T1 of the large-diameter ring 36 and the thickness T2 of the small-diameter ring 35 may be determined depending on the mounting orientation of the retainer 34. For example, when axially adjacent retainers 34 are mounted with their small-diameter rings 35 facing each other, the thickness T2 of the small-diameter ring 35 may be formed thicker than the thickness T1 of the large-diameter ring 36.

[0231] The specific difference in thickness between the thicknesses T1 and T2 may be determined by the load applied to the large-diameter ring 36 or the small-diameter ring 35 that rub against each other.

[0232] [14th Modification]

[0233] Figure 24 This is a perspective view of a portion of the retainer 34 according to the fourteenth modified example as viewed from the small-diameter ring 35 side. Figure 24 With the aforementioned Figure 2 Corresponding to the enlarged view of Section XXIV. Figure 25 This is a perspective view of a portion of the retainer 34 according to the fourteenth modified example as viewed from the large-diameter ring 36 side. Figure 25 With the aforementioned Figure 3 Corresponding to the enlarged view of part XXV.

[0234] like Figure 24 As shown, the column portion 37 of the retainer 34 has a small-diameter side rounded chamfered portion 46a formed at the connection portion with the small-diameter ring 35. More specifically, the column portion 37 has small-diameter side rounded chamfered portions 46a formed at the corners between the small-diameter side inclined portion 46 and both side surfaces 44c of the outer column portion 44.

[0235] As a result, a small-diameter-side rounded chamfered portion 46a is formed at the connection between the column portion 37 and the outer circumferential surface 35b of the small-diameter ring 35. The small-diameter-side rounded chamfered portion 46a is formed in an arc shape. Compared to a case where the connection between the column portion 37 and the outer circumferential surface 35b of the small-diameter ring 35 is angular, the small-diameter-side rounded chamfered portion 46a can prevent stress concentration at the connection.

[0236] On the other hand, Figure 25 As shown, the column portion 37 of the retainer 34 has a large-diameter rounded chamfered portion 47a formed at the connection portion with the large-diameter ring 36. More specifically, the column portion 37 has a large-diameter rounded chamfered portion 47a formed at the corners between the large-diameter inclined portion 47 and the side surface 44c of the outer column portion 44 and the side surface 45c of the inner column portion 45.

[0237] As a result, a large-diameter-side rounded chamfered portion 47a is formed at the connection between the column portion 37 and the inner circumferential surface 36c of the large-diameter ring 36. The large-diameter-side rounded chamfered portion 47a is formed in an arc shape. Compared to a case where the connection between the column portion 37 and the inner circumferential surface 36c of the large-diameter ring 36 is angular, the large-diameter-side rounded chamfered portion 47a can prevent stress concentration at the connection.

[0238] Therefore, according to the fourteenth modification, stress concentration on the retainer 34 can be alleviated by the small-diameter side round chamfered portion 46 a and the large-diameter side round chamfered portion 47 a , thereby preventing damage to the retainer 34 .

[0239] [15th Modification]

[0240] Figure 26 It is a perspective view of a portion of the retainer 34 according to the fifteenth modified example as viewed from the small-diameter ring 35 side. Figure 26 With the aforementioned Figure 24 Corresponding. Figure 27 This is a perspective view of a portion of the retainer 34 according to the fourteenth modified example as viewed from the large-diameter ring 36 side. Figure 27 With the aforementioned Figure 25 Corresponding.

[0241] like Figure 26 、 Figure 27 As shown, the difference between the fourteenth and fifteenth modified examples is that, whereas in the fourteenth modified example, the small-diameter side circular chamfered portion 46a and the large-diameter side circular chamfered portion 47a are formed on the column portion 37, in the fifteenth modified example, a small-diameter side flat chamfered portion 46b and a large-diameter side flat chamfered portion 47b are formed on the column portion 37 instead of the small-diameter side circular chamfered portion 46a and the large-diameter side circular chamfered portion 47a. Each flat chamfered portion 46b, 47b is formed flat.

[0242] Even in the case of such a configuration, the same effects as those of the above-mentioned 14th variant are achieved.

[0243] In addition, the present invention is not limited to the above-described embodiment, and includes embodiments in which various modifications are added to the above-described embodiment within a scope that does not depart from the gist of the present invention.

[0244] For example, in the above embodiment, an eccentric oscillating speed reducer 1 is described as an example of a rotary device, and an eccentric bearing 19 is provided in this speed reducer 1. However, this is not limiting, and the eccentric bearing 19 can be employed in various rotary devices using bearings. The inner ring 31 may not be integrally formed with the eccentric portions 13a and 13b, nor may the outer ring 32 be integrally formed with the external gears 15 and 16. The eccentric bearing 19 can be employed as a single bearing.

[0245] In the above embodiment, the eccentric bearing 19 is described as a so-called needle roller bearing. However, the present invention is not limited to this, and the structure of the eccentric bearing 19 can be adopted in various bearings having rolling elements. For example, the structure of the retainer 34 can also be adopted in a deep groove ball bearing.

[0246] In the above embodiment, the reduction gear 1 is described as an eccentric oscillating reduction gear having multiple (e.g., three) crankshafts 13. However, the present invention is not limited to this, and in this reduction gear, a single crankshaft 13 may be provided. In this case, the crankshaft 13 is coaxial with the first rotation axis A1.

[0247] In the above embodiment, the reduction gear 1 is described as having two external gears 15 and 16. However, this is not limiting; it suffices to have at least one external gear. Alternatively, it may have three or more external gears. The number of eccentric portions can be adjusted to match the number of external gears. Even with this configuration, the reduction gear 1 can still function as an eccentric oscillating reduction gear.

[0248] In the above embodiment, the radial width Wo of the large-diameter ring 36 is described as being greater than the radial width Ws of the small-diameter ring 35. However, this is not limiting; the radial width Wo of the large-diameter ring 36 and the radial width Ws of the small-diameter ring 35 can be arbitrarily determined. For example, the radial width Ws of the small-diameter ring 35 may be greater than the radial width Wo of the large-diameter ring 36. In this case, it is desirable that the column portion 37 be formed so that the pressing load applied to the rolling elements 33 of the inner column portion 45 is greater than the pressing load applied to the rolling elements 33 of the outer column portion 44.

[0249] In the above embodiment, the case where the small-diameter inclined portion 46 and the large-diameter inclined portion 47 are formed on the column portion 37 of the retainer 34 has been described. However, this is not limiting; at least one of the small-diameter inclined portion 46 and the large-diameter inclined portion 47 may be formed on the column portion 37. Even in this case, oil flow can be improved compared to a case where the inclined portions 46 and 47 are not formed.

[0250] In the above embodiment, the side surfaces 44c of the outer column portion 44 are inclined so that the thickness of the outer column portion 44 gradually increases in the radial direction outward. The side surfaces 45c of the inner column portion 45 are inclined so that the thickness of the inner column portion 45 gradually increases in the radial direction inward. However, this is not limiting, and the shape of the column portion 37 can be arbitrarily determined.

[0251] However, when the column portion 37 is configured by the outer column portion 44 and the inner column portion 45 , the column portion 37 is formed so that the rolling elements 33 come into contact with the outer column portion 44 and the inner column portion 45 when the reduction gear 1 is driven.

[0252] The column portion 37 may not be formed using the outer column portion 44 and the inner column portion 45. In this case, the column portion 37 may be formed so that, when unloaded, the rolling elements 33 are in contact with the outer circumferential surface 35b of the small-diameter ring 35 and the inner circumferential surface 36c of the large-diameter ring 36 of the column portion 37, as viewed in the axial direction. More preferably, the column portion 37 may be formed so that, when viewed in the axial direction, the rolling elements 33 are always in contact with the outer circumferential surface 35b of the small-diameter ring 35 and the inner circumferential surface 36c of the large-diameter ring 36 of the column portion 37, from the time when no load is applied to the time when the reduction gear 1 is driven.

[0253] In the embodiments disclosed in this specification, a component composed of multiple objects may be integrated into one piece, or a component composed of one object may be divided into multiple pieces. Regardless of whether or not the components are integrated, they may be configured in a manner that achieves the purpose of the invention.

Claims

1. A retainer for retaining a rolling element of a rolling bearing having a plurality of rolling elements arranged in a circumferential direction, wherein: The retainer has: a circular, small-diameter ring; an annular large-diameter ring, which is arranged axially apart from the small-diameter ring; and A plurality of columnar portions extending in the radial direction so as to connect the small-diameter ring and the large-diameter ring, The plurality of columnar portions are arranged between the rolling elements adjacent to each other in the circumferential direction. When the outer diameter of the small-diameter ring is Φso and the inner diameter of the large-diameter ring is Φbi, The outer diameter Φso and the inner diameter Φbi satisfy Φso≤Φbi.

2. The holder according to claim 1, wherein A small-diameter-side inclined portion is formed at a corner portion of the column portion located on the small-diameter ring side and radially outward of the small-diameter ring. The small-diameter-side inclined portion is inclined so as to gradually move radially inward as it moves axially toward the small-diameter ring.

3. The holder according to claim 1, wherein A large-diameter-side inclined portion is formed at a corner portion of the column portion located on the large-diameter ring side and radially inward of the large-diameter ring. The large-diameter-side inclined portion is inclined so as to gradually be directed radially outward as it moves axially toward the large-diameter ring. The retainer according to claim 1 , wherein: At least one of a small-diameter side inclined portion and a large-diameter side inclined portion is formed on the column portion. The small-diameter side inclined portion is arranged at a corner portion located on the small-diameter ring side and radially outward of the small-diameter ring, and is inclined gradually radially inward as it moves axially toward the small-diameter ring. The large diameter side inclined portion is arranged at a corner portion located on the large diameter ring side and radially inward of the large diameter ring. The large-diameter-side inclined portion is inclined so as to gradually be directed radially outward as it moves axially toward the large-diameter ring.

5. The holder according to claim 4, wherein An inclined convex portion is formed on at least one of the small-diameter side inclined portion and the large-diameter side inclined portion. The circumferential width of the inclined convex portion is smaller than the circumferential width of the small-diameter-side inclined portion or the large-diameter-side inclined portion in which the inclined convex portion is formed. The holder according to claim 5 , wherein: The inclined protrusion extends in the radial direction when viewed from the axial direction.

7. The holder according to claim 5, wherein The inclined protrusion extends in a direction intersecting the radial direction when viewed from the axial direction.

8. The holder according to claim 4, wherein An end surface convex portion is formed on the radially outer end surface of the column portion.

9. The holder according to claim 8, wherein The end surface convex portion is formed such that a circumferential width thereof decreases from the small-diameter ring toward the large-diameter ring.

10. The holder according to claim 4, wherein At least one of the large-diameter ring and the small-diameter ring has a recessed portion formed between two of the columnar portions adjacent to each other in the circumferential direction on an axial end surface.

11. The holder according to claim 10, wherein The recessed portion is formed over the entire radial direction of at least one of the large-diameter ring and the small-diameter ring.

12. The holder according to claim 1, wherein The column portion is integrally formed with an outer column portion arranged on the outer side in the radial direction and an inner column portion arranged on the inner side in the radial direction. The outer column portion and the inner column portion are respectively formed so as to come into contact with the rolling element.

13. The holder according to claim 12, wherein: The outer column portion and the inner column portion are formed so that a load pressing the outer column portion by the rolling element and a load pressing the inner column portion by the rolling element are different.

14. The holder according to claim 13, wherein The outer column portion extends from the surface of the large-diameter ring facing the small-diameter ring to the small-diameter ring. The inner column portion extends from the surface of the small-diameter ring facing the large-diameter ring to the large-diameter ring. The load applied to the outer column portion or the inner column portion that is engaged with the one of the large diameter ring and the small diameter ring with a larger radial width is greater than the load applied to the outer column portion or the inner column portion that is engaged with the one of the large diameter ring and the small diameter ring with a smaller radial width.

15. The retainer according to any one of claims 12 to 14, wherein: The two circumferential side surfaces of the outer column portion are formed to be inclined so that the plate thickness of the outer column portion gradually increases toward the outer side in the radial direction. Both side surfaces in the circumferential direction of the inner column portion are formed to be inclined so that the plate thickness of the inner column portion gradually increases toward the inner side in the radial direction.

16. The holder according to claim 15, wherein When the rolling element is in contact with the column portion without load, a straight line passing through the center of an angle between the outer side surface of one of the two side surfaces of the outer column portion and the inner side surface of the two side surfaces of the inner column portion that is coplanar with the outer side surface deviates from the central axis of the rolling element.

17. The retainer according to claim 1, wherein The column portion is formed so as to contact the rolling element between the outer peripheral surface of the small-diameter ring and the inner peripheral surface of the large-diameter ring when viewed in the axial direction.

18. A rolling bearing comprising: inner circle; an outer ring disposed radially outward of the inner ring; a plurality of rolling elements disposed between the inner ring and the outer ring and arranged in a circumferential direction; and a retainer that retains the plurality of rolling elements, The retainer comprises: a circular, small-diameter ring; an annular large-diameter ring, which is arranged axially apart from the small-diameter ring; and A plurality of columnar portions extending in the radial direction so as to connect the small-diameter ring and the large-diameter ring, and arranged between the rolling elements adjacent to each other in the circumferential direction, When the outer diameter of the small-diameter ring is Φso and the inner diameter of the large-diameter ring is Φbi, The outer diameter Φso and the inner diameter Φbi satisfy Φso≤Φbi.

19. A rotating device comprising: a housing having an internal gear; a gear rack rotatably supported on the housing; at least one crankshaft having a shaft body rotatably supported on the carrier via a first rolling bearing; and an external gear meshing with the internal gear, The crankshaft has an eccentric portion that is eccentric with respect to the rotation axis of the shaft body. The external gear is rotatably supported by the eccentric portion via a second rolling bearing. The second rolling bearing includes: inner circle; an outer ring disposed radially outward of the inner ring; a plurality of rolling elements disposed between the inner ring and the outer ring and arranged in a circumferential direction; and a retainer that retains the plurality of rolling elements, The retainer comprises: a circular, small-diameter ring; an annular large-diameter ring, which is arranged axially apart from the small-diameter ring; and A plurality of columnar portions extending in the radial direction so as to connect the small-diameter ring and the large-diameter ring, and arranged between the rolling elements adjacent to each other in the circumferential direction, When the outer diameter of the small-diameter ring is Φso and the inner diameter of the large-diameter ring is Φbi, The outer diameter Φso and the inner diameter Φbi satisfy Φso≤Φbi.

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