Retainer, rolling bearing, and rotating device

Abstract

To provide a retainer, a rolling bearing, and a rotating device which can be easily manufactured.SOLUTION: A retainer 34 according to an embodiment includes an annular small-diameter ring 35, an annular large-diameter ring 36 separated from the small-diameter ring 35 in an axial direction, and a plurality of pillars 37 extending in a radial direction to connect the small-diameter ring 35 and the large-diameter ring 36 and arranged between rolling elements adjacent to each other in a circumferential direction. A relation Φso≤Φbi is satisfied when an outside diameter of the small-diameter ring 35 is Φso and an inside diameter of the large-diameter ring 36 is Φbi.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] Rotating devices such as reducers are equipped with multiple rolling bearings. One example of such rolling bearings is a cylindrical roller bearing. A cylindrical roller bearing includes an inner ring, an outer ring positioned radially outward of the inner ring, multiple cylindrical rollers as rolling elements positioned between the inner ring and the outer ring and aligned circumferentially, and a cage that holds the cylindrical rollers. The cage includes a pair of annular plates positioned on both axial sides of each cylindrical roller and multiple pillars connecting the pair of annular plates. The pillars are arranged at equal intervals circumferentially. Cylindrical rollers are positioned in multiple pockets defined by the pair of annular plates and the pillars. Such cages are sometimes injection molded from resin. This configuration improves cage productivity. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-139455 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned conventional technology, a pair of annular plates are aligned in the axial direction, and a pocket portion is formed between the pair of annular plates. Therefore, the mold release direction cannot be simply in the axial direction of the cage. To form the pocket portion, a slide core that slides radially during mold release is required. This makes the mold structure complicated, which has led to the issue of cages being difficult to manufacture.

[0005] The present invention provides a cage, a rolling bearing, and a rotating device that can be easily manufactured. [Means for solving the problem]

[0006] A cage according to one embodiment of the present invention is a cage that holds rolling elements of a rolling bearing having a plurality of rolling elements arranged circumferentially, and comprises: an annular small diameter ring; an annular large diameter ring arranged axially apart from the small diameter ring; and a plurality of pillar portions that extend radially to connect the small diameter ring and the large diameter ring and are arranged between adjacent rolling elements in the circumferential direction, wherein 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.

[0007] With this configuration, when injection molding the cage, even if the mold is released only in the axial direction of the cage, a pocket defined by the large-diameter ring, small-diameter ring, and column portion can be formed. This simplifies the mold structure and makes it easy to manufacture the cage.

[0008] In the above configuration, a small diameter side inclined portion is formed at a corner portion located on the small diameter ring side of the column portion and radially outward from the small diameter ring, and the small diameter side inclined portion may be inclined so as to gradually move radially inward as it approaches the small diameter ring in the axial direction.

[0009] In the above configuration, a large diameter side inclined portion is formed at a corner portion located on the large diameter ring side of the column portion and radially inward from the large diameter ring, and the large diameter side inclined portion may be inclined so as to gradually move radially outward as it approaches the large diameter ring in the axial direction.

[0010] In the above configuration, the column portion may have at least one of a small diameter side inclined portion and a large diameter side inclined portion formed thereon, the small diameter side inclined portion being located at a corner portion on the small diameter ring side and radially outward from the small diameter ring, and inclining gradually radially inward as it approaches the small diameter ring in the axial direction, and the large diameter side inclined portion being located at a corner portion on the large diameter ring side and radially inward from the large diameter ring, and inclining gradually radially outward as it approaches the large diameter ring in the axial direction.

[0011] In the above configuration, an inclined convex portion is formed on at least one of the small diameter side inclined portion and the large diameter side inclined portion, and the circumferential width of the inclined convex portion may be 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.

[0012] In the above configuration, the inclined convex portion may extend along a radial direction when viewed from the axial direction.

[0013] In the above configuration, the inclined convex portion may extend in a direction intersecting with the radial direction when viewed from the axial direction.

[0014] In the above configuration, an end surface convex portion may be formed on a radially outer end surface of the column portion.

[0015] In the above configuration, the end surface convex portion may be formed so that its circumferential width decreases from the small diameter ring toward the large diameter ring.

[0016] In the above configuration, a recess may be formed on an end surface in the axial direction of at least one of the large diameter ring and the small diameter ring, and between two of the pillar portions adjacent in the circumferential direction.

[0017] 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.

[0018] In the above configuration, the column portion may be integrally formed with an outer column portion arranged radially outward and an inner column portion arranged radially inward, and the outer column portion and the inner column portion may each be formed to come into contact with the rolling element.

[0019] In the above configuration, the outer column portion and the inner column portion may be formed so that the load with which the rolling elements press the outer column portion is different from the load with which the rolling elements press the inner column portion.

[0020] In the above configuration, the outer column extends from the surface of the large diameter ring facing the small diameter ring to the small diameter ring, and the inner column extends from the surface of the small diameter ring facing the large diameter ring to the large diameter ring, and the load applied to the outer column or the inner column joined to the large diameter ring or the small diameter ring that has a larger radial width may be greater than the load applied to the outer column or the inner column joined to the small diameter ring that has a smaller radial width.

[0021] In the above configuration, both circumferential side surfaces of the outer pillar portion may be formed with an inclination such that the thickness of the outer pillar portion gradually increases as the pillar portion moves radially outward, and both circumferential side surfaces of the inner pillar portion may be formed with an inclination such that the thickness of the inner pillar portion gradually increases as the pillar portion moves radially inward.

[0022] In the above configuration, when the rolling element is in contact with the column portion without load, a straight line passing through the center of the angle between one of the outer side surfaces of the outer column portion and one of the inner side surfaces of the inner column portion that is on the same plane as the outer side surface may be deviated from the central axis of the rolling element.

[0023] In the above configuration, the pillar portion may be formed so as to come into contact with the rolling elements 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.

[0024] A rolling bearing according to another aspect of the present invention comprises an inner ring, an outer ring arranged radially outward of the inner ring, a plurality of rolling elements arranged between the inner ring and the outer ring and aligned circumferentially, and a cage for holding the plurality of rolling elements, wherein the cage comprises an annular small diameter ring, an annular large diameter ring arranged axially apart from the small diameter ring, and a plurality of pillar portions extending radially to connect the small diameter ring and the large diameter ring and arranged between circumferentially adjacent rolling elements, wherein 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.

[0025] With this configuration, when the cage is injection molded, even if the mold is released only in the axial direction of the cage, pockets defined by the large-diameter ring, small-diameter ring, and column portions can be formed. This simplifies the mold structure, facilitating the manufacture of cages and, ultimately, rolling bearings.

[0026] A rotation device according to another aspect of the present invention includes a case having an internal gear, a carrier rotatably supported by the case, a shaft body rotatably supported by the carrier via a first rolling bearing, and at least one crankshaft provided on the shaft body and having an eccentric portion eccentric with respect to the rotation axis of the shaft body, and an oscillating external gear rotatably supported by the eccentric portion via a second rolling bearing and meshing with the internal gear, wherein the second rolling bearing is provided on an inner ring and a second rolling bearing disposed radially outward of the inner ring. the outer ring and the outer ring are arranged in a circumferential direction, a plurality of rolling elements arranged between the inner ring and the outer ring and lined up in a circumferential direction, and a cage that holds the plurality of rolling elements, wherein the cage comprises an annular small diameter ring, an annular large diameter ring arranged axially apart from the small diameter ring, and a plurality of pillar portions that extend radially to connect the small diameter ring and the large diameter ring and are arranged between the rolling elements that are adjacent in the circumferential direction, wherein 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.

[0027] With this configuration, when the cage is injection molded, even if the mold is released only in the axial direction of the cage, a pocket defined by the large-diameter ring, the small-diameter ring, and the column portion can be formed. This simplifies the mold structure, facilitating the manufacture of the cage and, ultimately, the manufacture of the rotating device. [Effects of the Invention]

[0028] The above-described cage, rolling bearing, and rotating device can be easily manufactured. [Brief explanation of the drawings]

[0029] [Figure 1] 1 is a cross-sectional view of a reduction gear transmission according to an embodiment of the present invention. [Figure 2] 1 is a perspective view of a rolling element and a cage according to an embodiment of the present invention, viewed from the outside in the axial direction. [Figure 3] 1 is a perspective view of a rolling element and a cage according to an embodiment of the present invention, viewed from the center side in the axial direction. [Figure 4] 1 is a cross-sectional view taken along the axial direction of a cage according to an embodiment of the present invention. [Figure 5] FIG. 3 is an enlarged radial cross-sectional view of a pillar portion of an eccentric portion bearing according to an embodiment of the present invention. [Figure 6] 10A and 10B are explanatory diagrams showing the behavior of a column portion in an embodiment of the present invention. [Figure 7] 5A to 5C are explanatory views of a method for manufacturing a cage according to an embodiment of the present invention. [Figure 8] FIG. 10 is a side view of a pillar portion in a first modified example of the embodiment of the present invention, as viewed from the axial direction. [Figure 9] FIG. 10 is a side view of a pillar portion in a second modified example of the embodiment of the present invention, as viewed from the axial direction. [Figure 10] FIG. 11 is a perspective view of a part of a cage in a third modified example, as viewed from the small diameter ring side. [Figure 11] FIG. 11 is a perspective view of a part of a cage in a third modified example, viewed from the large diameter ring side. [Figure 12]FIG. 11 is a perspective view of a part of a cage in a fourth modified example, viewed from the small diameter ring side. [Figure 13] FIG. 11 is a perspective view of a part of a cage in a fourth modified example, viewed from the large diameter ring side. [Figure 14] FIG. 13 is a perspective view of a part of a cage in a fifth modified example, viewed from the small diameter ring side. [Figure 15] FIG. 13 is a perspective view of a part of a cage in a sixth modified example, viewed from the small diameter ring side. [Figure 16] FIG. 13 is a perspective view of a part of a cage in a seventh modified example, viewed from the small diameter ring side. [Figure 17] FIG. 13 is a perspective view of a part of a cage in an eighth modified example, viewed from the small diameter ring side. [Figure 18] FIG. 13 is a perspective view of a part of a cage in a ninth modified example, viewed from the small diameter ring side. [Figure 19] FIG. 13 is a perspective view of a part of a cage in a ninth modified example, viewed from the large diameter ring side. [Figure 20] FIG. 23 is a perspective view of a crankshaft and an eccentric bearing in a tenth modified example, viewed from the base plate side. [Figure 21] FIG. 23 is a partially enlarged cross-sectional view taken along the axial direction of a large-diameter ring in an eleventh modified example. [Figure 22] FIG. 23 is a partially enlarged cross-sectional view taken along the axial direction of a large-diameter ring in a twelfth modified example. [Figure 23] FIG. 23 is a partially enlarged view of a cross section taken along the axial direction of a cage in a thirteenth modified example. [Figure 24] FIG. 23 is a perspective view of a part of a cage in a fourteenth modified example, viewed from the small diameter ring side. [Figure 25] FIG. 23 is a perspective view of a part of a cage in a fourteenth modified example, viewed from the large diameter ring side. [Figure 26] FIG. 23 is a perspective view of a part of a cage in a fifteenth modified example, viewed from the small diameter ring side. [Figure 27] FIG. 23 is a perspective view of a part of a cage in a fifteenth modified example, viewed from the large diameter ring side. DETAILED DESCRIPTION OF THE INVENTION

[0030] Next, an embodiment of the present invention will be described with reference to the drawings.

[0031] <Deceleration device> FIG. 1 is a cross-sectional view of a reduction gear transmission 1, which is a rotating device. As shown in Fig. 1, the reduction gear 1 reduces the rotation speed of, for example, an electric motor (not shown) and outputs the reduced speed. The reduction gear 1 is a so-called eccentric oscillating reduction gear. The reduction gear 1 includes a cylindrical case 2, a carrier 3 rotatably provided radially inside the case 2, and a reduction mechanism 4 connected to the carrier 3. The central axis of the case 2 and the rotation axis of the carrier 3 coincide with each other. In the following description, the central axis and the rotation axis will be commonly referred to as the first rotation axis A1. The direction parallel to the first rotation axis A1 will be referred to as the axial direction. The rotation direction of the carrier 3 will be referred to as the circumferential direction. The radial direction of the case 2, which is perpendicular to the axial and circumferential directions, will be simply referred to as the radial direction.

[0032] <Case> An outer flange portion 2a that protrudes radially outward is integrally formed on the outer peripheral surface of the case 2. A plurality of bolt holes 2b into which bolts (not shown) are inserted 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 these bolt holes 2b and tightened to, for example, the arm of an industrial robot to secure the reduction gear device 1.

[0033] A plurality of pin grooves 2c are formed along the axial direction on the inner peripheral surface of the case 2. The pin grooves 2c are arranged at equal intervals in the circumferential direction. An internally toothed pin 5 is fitted into each pin groove 2c. The internally toothed pin 5 functions as an internal tooth that meshes with oscillating external gears 15 and 16 of the reduction mechanism 4, which will be described later. Main bearings 6 are provided on both axial sides of the inner circumferential surface of the case 2. The carrier 3 is rotatably supported by the case 2 via the main bearings 6. The main bearings 6 are, for example, angular contact ball bearings.

[0034] <Career> The carrier 3 includes a disk-shaped base plate portion 7 and an end plate portion 8 that are arranged opposite each other in the axial direction, and three pillar portions 9 that are formed to protrude from the base plate portion 7 toward the end plate portion 8. The pillar portions 9 are arranged at equal intervals in the circumferential direction. End plates 8 are arranged on the tips 9a of the pillar portions 9. The end plates 8 are fixed to the pillar portions 9 with bolts 10. In this state, a space having a constant width in the axial direction is formed between the base plate portion 7 and the end plates 8. A pin hole 12a is formed in the column portion 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 portion 8 relative to the base plate portion 7. The pin 11 is also inserted or press-fitted into a pin hole 12b provided in the end plate portion 8.

[0035] The outer peripheral surfaces of the base plate portion 7 and the end plate portion 8 are rotatably supported by the case 2 via the corresponding main bearings 6. Shaft insertion holes 7a and 8a are formed in the radial center of the base plate portion 7 and the end plate portion 8, respectively. The two shaft insertion holes 7a and 8a are arranged coaxially. Three crank insertion holes 7b and 8b are formed in the base plate portion 7 and the end plate portion 8, respectively, between adjacent column portions 9 in the circumferential direction. Each crank insertion hole 7b and 8b is arranged coaxially. In other words, the central axes A2 of the axially opposing crank insertion holes 7b and 8b are parallel to the first rotation axis A1. A crank bearing 18 is provided in each crank insertion hole 7b and 8b. The crank bearings 18 are, for example, tapered roller bearings.

[0036] <Deceleration mechanism> The reduction mechanism 4 rotates the carrier 3 at a rotation speed that is reduced by a fixed ratio relative to the rotation speed of a motor shaft of an electric motor (not shown), for example. The reduction mechanism 4 includes three crankshafts 13 inserted into the crank insertion holes 7b, 8b, a transmission spur gear 14 provided at the axial end of each crankshaft 13, and two oscillating external gears 15, 16 (a first oscillating external gear 15 and a second oscillating external gear 16) provided between the base plate portion 7 and the end plate portion 8.

[0037] The transmission spur gear 14 is meshed 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.

[0038] Each crankshaft 13 is rotatably supported by the carrier 3 (the base plate portion 7 and the end plate portion 8) via a respective crank bearing 18. The crankshaft 13 has 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. Both axial ends of the shaft body 13c are rotatably supported by the carrier 3 (the base plate portion 7 and the end plate portion 8) via the crank bearings 18. In the following description, both axial sides of the shaft body 13c will be referred to as the axial outer sides, and the axial center side of the shaft body 13c where the eccentric portions 13a and 13b are arranged will be simply referred to as the axial center side.

[0039] The shaft body 13c and the transmission spur gear 14 are coaxially arranged and integrated. That is, the crankshaft 13 and the transmission spur gear 14 rotate integrally about a central axis A2. Hereinafter, the central axis A2 will be referred to as the second rotation axis A2 of the crankshaft 13.

[0040] The first eccentric portion 13a and the second eccentric portion 13b are eccentric from the second rotation axis A2. The first eccentric portion 13a and the second eccentric portion 13b are disposed adjacent to each other in the axial direction between the two crank bearings 18. In other words, the first eccentric portion 13a and the second eccentric portion 13b are disposed adjacent to each other in the axial direction between the base plate portion 7 and the end plate portion 8. The first eccentric portion 13a and the second eccentric portion 13b are disposed with a phase angle shift of 180°.

[0041] Each of the eccentric portions 13a, 13b is provided with an eccentric portion bearing 19 (an example of a bearing in the claims). Details of the eccentric portion bearing 19 will be described later. Axial movement of the eccentric portion bearing 19 is restricted by a washer 21 provided on the axial outside of each of the eccentric portions 13a, 13b. The first oscillating external gear 15 and the second oscillating external gear 16 are rotatably supported on each crankshaft 13 via the eccentric portion bearing 19.

[0042] The first oscillating external gear 15 and the second oscillating external gear 16 are disposed in the space between the base plate portion 7 and the end plate portion 8. The first oscillating external gear 15 and the second oscillating external gear 16 oscillate and rotate in accordance with the rotation of the crankshaft 13. That is, the first oscillating external gear 15 and the second oscillating external gear 16 are formed with through holes 15a, 16a in which an eccentric portion bearing 19 is provided. As a result, 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 oscillating external gear 15 and the second oscillating external gear 16 are oscillated and rotated via the eccentric portion bearing 19.

[0043] The first oscillating external gear 15 and the second oscillating external gear 16 are respectively formed with openings 15b, 16b to avoid interference with the column portion 9. Shaft insertion holes 15c, 16c are formed in the radial centers of the first oscillating external gear 15 and the second oscillating external gear 16. External teeth 15d, 16d are formed on the outer periphery of the first oscillating external gear 15 and the outer periphery of the second oscillating external gear 16, respectively. The number of teeth of each of the external teeth 15d, 16d is, for example, one less than the number of internal tooth pins 5 of the case 2.

[0044] <Eccentric bearing> The eccentric portion bearing 19 is a so-called needle bearing. The eccentric portion bearing 19 includes an annular inner ring 31 integrated with each of the eccentric portions 13a, 13b of the crankshaft 13, an annular outer ring 32 integrated with each of the oscillating external gears 15, 16, a plurality of rolling elements 33 arranged between the inner ring 31 and the outer ring 32, and a cage 34 that holds the rolling elements 33. The rolling elements 33 are needle rollers arranged parallel to the axial direction. The rolling elements 33 are arranged side by side in the circumferential direction of the inner ring 31 and the outer ring 32.

[0045] <Cage> The cage 34 is made of resin. For example, nylon resin containing glass can be used as the resin. However, the resin is not limited to this, and various resins can be used.

[0046] Fig. 2 is a perspective view of the rolling elements 33 and the cage 34 of the eccentric bearing 19 as seen from the outside in the axial direction. Fig. 3 is a perspective view of the rolling elements 33 and the cage 34 of the eccentric bearing 19 as seen from the center side in the axial direction. Fig. 4 is a cross-sectional view of the cage 34 along the axial direction. As shown in Figures 2 to 4, the retainer 34 is integrally formed with an annular small-diameter ring 35 that is positioned axially outward from the rolling elements 33, a large-diameter ring 36 that is positioned axially toward the center from the rolling elements 33, and a plurality of pillar portions 37 that connect the small-diameter ring 35 and the large-diameter ring 36.

[0047] The small diameter ring 35 is formed to fit along the outer peripheral surface of the inner ring 31. That is, the inner diameter Φsi of the small diameter ring 35 is slightly larger than the outer diameter of the inner ring 31. An outer end surface 35d of the small diameter ring 35 on the outside in the axial direction comes into contact with the washer 21. This restricts the eccentric portion bearing 19 from moving outward in the axial direction.

[0048] The large diameter ring 36 is formed to fit along the inner peripheral surface of the outer ring 32. In other words, the outer diameter Φbo of the large diameter ring 36 is slightly smaller than the inner diameter of the outer ring 32. In the two eccentric portion bearings 19 aligned in the axial direction, the outer end faces 36d of the large diameter rings 36 on the axially central side are in contact with each other. This restricts the eccentric portion bearings 19 from moving toward the center in the axial direction.

[0049] The outer diameter Φso of the small diameter ring 35 and the inner diameter Φbi of the large diameter ring 36 are Φso≦Φbi (1) Meet the following. The radial width Wo of the large diameter ring 36 is larger than the radial width Ws of the small diameter ring 35 .

[0050] Figure 5 is an enlarged radial cross-sectional view of the column portion 37 of the eccentric portion bearing 19. Figure 5 is a view from the axial outside to the axial center. For ease of understanding, Figure 5 shows the small diameter ring 35 in a see-through manner. 2 to 5, the pillar portions 37 extend along the axial direction and are arranged at equal intervals in the circumferential direction. The rolling elements 33 are arranged in pockets 41 defined by the pillar portions 37, the small diameter ring 35, and the large diameter ring 36.

[0051] The pillar portion 37 is formed integrally with an outer pillar portion 44 disposed on the radially outer side and an inner pillar portion 45 disposed on the radially inner side. The outer pillar portion 44 extends from an opposing surface 36a of the large diameter ring 36 that faces the small diameter ring 35 to the small diameter ring 35. The outer end of the outer pillar portion 44 in the axial direction (on the small diameter ring 35 side) is joined to the outer peripheral surface 35b of the small diameter ring 35.

[0052] The radially inner inner end surface 44a of the outer pillar portion 44 is located radially inward of the outer peripheral surface 35b of the small diameter ring 35. The end portion of the outer pillar portion 44 on the axial center side (the large diameter ring 36 side) extends so as to be joined to the inner peripheral surface 36c of the large diameter ring 36. The radially outer outer end surface 44b of the outer pillar portion 44 is located on the same plane as the outer peripheral surface 36b of the large diameter ring 36.

[0053] A small diameter side inclined portion 46 is formed at a corner located on the axial outer side 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. Both circumferential side surfaces 44c of the outer pillar portion 44 are inclined so that the circumferential thickness of the outer pillar portion 44 gradually increases radially outward. In other words, the cross-sectional shape of the outer pillar portion 44 along the radial direction is an isosceles trapezoid. The circumferential width of the outer end surface 44b of the outer pillar portion 44 is greater than the circumferential width of the inner end surface 44a.

[0054] The inner pillar portion 45 extends from an opposing surface 35a of the small diameter ring 35 that faces the large diameter ring 36 to the large diameter ring 36. A radially outer end surface 45b of the inner pillar portion 45 is joined to an inner end surface 44a of the outer pillar portion 44. A radially inner end surface 45a of the inner pillar portion 45 is located on the same plane as the inner circumferential surface 35c of the small diameter ring 35.

[0055] A large-diameter-side inclined portion 47 is formed at a corner located toward the axial center of the inner pillar portion 45 and radially inward of the large-diameter ring 36, and at an end portion of the outer pillar portion 44 toward the axial center and radially inward of the large-diameter ring 36. The large-diameter-side inclined portion 47 is inclined gradually radially outward as it approaches the axial center.

[0056] Both circumferential side surfaces 45c of the inner pillar portion 45 are inclined so that the circumferential thickness of the inner pillar portion 45 gradually increases radially inward. In other words, the cross-sectional shape of the inner pillar portion 45 along the radial direction is an isosceles trapezoid. The circumferential width of the inner end surface 45a of the inner pillar portion 45 is greater than the circumferential width of the outer end surface 45b. The pillar portion 37 formed in this manner has the narrowest shape at the joint between the outer pillar portion 44 and the inner pillar portion 45 (the inner end surface 44a of the outer pillar portion 44 and the outer end surface 45b of the inner pillar portion 45). In other words, the opening area of ​​the pocket portion 41 becomes smaller toward the radially outward and radially inward.

[0057] When the rolling elements 33 are 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 that is located on the same plane as this side surface 44c is offset from the central axis C of the rolling elements 33. In other words, the straight line L is a straight line such that the angle θ1 between the line L and the side surface 44c of the outer column portion 44 and the angle θ2 between the line L and the side surface 45c of the inner column portion 45 are the same. The no-load state refers to a state in which no force is acting to press the column portion 37 against the rolling element 33. In other words, the no-load state can be said to be a design value.

[0058] Specifically, the deviation between the line L and the central axis C means that the 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 under no load, the rolling element 33 is in contact with the side surface 44c of the outer column portion 44 (see point P1 in FIG. 5). When the rolling element 33 is in contact with the column portion 37 under no load, a minute gap G is formed between the rolling element 33 and the side surface 45c of the inner column portion 45. The size of this minute gap G is, for example, approximately 0.1 mm or less.

[0059] <Operation of the reduction gear> Next, the operation of the reduction gear 1 will be described. The transmission spur gear 14 and the crankshaft 13 are rotated integrally by an electric motor (not shown). Furthermore, the first oscillating external gear 15 and the second oscillating external gear 16 are oscillatingly rotated. As a result of this oscillating rotation, some of the external teeth 15d, 16d of each oscillating external gear 15, 16 mesh with the internal pin 5 of the case 2. The number of teeth of each external tooth 15d, 16d is, for example, one less than the number of internal pins 5. Therefore, each oscillating external gear 15, 16 rotates on its axis such that the meshing points of each external tooth 15d, 16d with respect to the internal pin 5 (case 2) are sequentially shifted in the circumferential direction. This rotation is decelerated relative to the rotation of the crankshaft 13.

[0060] As each of the oscillating external gears 15, 16 rotates, each of the crankshafts 13 also revolves around the first axis of rotation A1 while rotating about the second axis of rotation A2. Each of the crankshafts 13 is rotatably supported by the carrier 3 (base plate portion 7, end plate portion 8). Therefore, the carrier 3 rotates as each of the crankshafts 13 revolves. As a result, the reduction gear 1 reduces the rotation of an electric motor (motor shaft) (not shown) and outputs it from the carrier 3. If the carrier 3 were fixed to the arm of an industrial robot or the like, the reduction gear 1 could reduce the rotation of the electric motor and output it from the case 2.

[0061] Next, the function of the eccentric bearing 19 will be described. As the crankshaft 13 and the oscillating external gears 15, 16 rotate, the inner ring 31 (each of the eccentric parts 13a, 13b) and the outer ring 32 (each of the oscillating external gears 15, 16) of the eccentric part bearing 19 rotate relative to each other. As a result, the multiple rolling elements 33 and the cage 34 rotate. Because each rolling element 33 is held by a cage 34, the rolling elements 33 rotate while maintaining a constant interval in the circumferential direction. The opening area of ​​the pocket portion 41 in the cage 34 becomes smaller toward the outside in the radial direction. Therefore, the cage 34 can prevent the rolling elements 33 from falling off each eccentric portion bearing 19.

[0062] The pillar portion 37 is formed with a small-diameter-side inclined portion 46 and a large-diameter-side inclined portion 47. This allows the pillar portion 37 to surround both circumferential sides of the rolling element 33, while opening the pocket portion 41 as large as possible. This improves the flow of lubricating oil from the outside to the inside of the eccentric portion bearing 19 (hereinafter referred to as oil permeability). By improving oil permeability, the rolling element 33 and the cage 34 can rotate smoothly between the inner ring 31 and the outer ring 32.

[0063] When the rolling elements 33 and the cage 34 rotate, the small diameter ring 35 comes into contact with the washer 21, generating sliding friction resistance (see, for example, arrow F1 in FIGS. 2 and 3). The large diameter rings 36 adjacent to each other in the axial direction come into contact with each other, generating sliding friction resistance (see, for example, arrow F2 in FIGS. 2 and 3). On the other hand, a load (hereinafter also referred to as a pressing load of the rolling element 33) is generated by the rolling element 33 pressing the column portion 37. This load is in the opposite direction to the direction in which the sliding friction resistance force is applied (see, for example, arrow F3 in FIGS. 2 and 3).

[0064] Here, the outer diameter Φso of the small diameter ring 35 of the cage 34 and the inner diameter Φbi of the large diameter ring 36 satisfy the above formula (1). Of the pillar portions 37, the outer pillar portions 44 are mainly joined to the opposing surface 36a of the large diameter ring 36. Of the pillar portions 37, the inner pillar portions 45 extend mainly to 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 pillar portion 44 (see, for example, arrow F4 in FIG. 2). A torsional load is generated at the joint between the inner peripheral surface 36c of the large diameter ring 36 and the outer pillar portion 44 (see, for example, arrow F5 in FIG. 3).

[0065] Fig. 6 is an explanatory diagram showing the behavior of the column portion 37. Fig. 6 corresponds to Fig. 5 described above. 5, when the rolling elements 33 are in contact with the column portion 37 under no load, the rolling elements 33 are in contact with the side surface 44c of the outer column portion 44. Therefore, a pressing load of the rolling elements 33 is first generated on the outer column portion 44 (see arrow F6 in FIG. 5). 6, the pillar portion 37 undergoes slight elastic deformation, and the rolling elements 33 come into contact with the side surface 44c of the outer pillar portion 44 and, at the same time, the rolling elements 33 come into contact with the side surface 45c of the inner pillar portion 45 (see points P1 and P2 in FIG. 6). As a result, the pressing load of the rolling elements 33 is distributed between the outer pillar portion 44 and the inner pillar portion 45 (see arrows F6' and F7 in FIG. 6).

[0066] In this way, the pillar portion 37 is formed so that the rolling elements 33 come into contact with the outer pillar portion 44 and the inner pillar portion 45. The pressing load of the rolling elements 33 is distributed to the outer pillar portion 44 and the inner pillar portion 45, thereby reducing each torsional load (arrows F4, F5). In other words, the pressing load of the rolling elements 33 that contributes to each torsional load is reduced.

[0067] That is, for example, the load applied to the outer column portion 44 mainly contributes to the torsional load applied to the joint between the outer peripheral surface 35b of the small-diameter ring 35 and the outer column portion 44. For example, the load applied to the inner column portion 45 mainly contributes to the torsional load applied to the joint between the inner peripheral surface 36c of the large-diameter ring 36 and the outer column portion 44. In this way, the pressing load of the rolling elements 33 against the column portion 37 is not concentrated in one place, but is dispersed into loads that respectively contribute to each torsional load (arrows F4 and F5). As a result, each torsional load is reduced. In addition, the pressing load of the rolling element 33 on the outer column portion 44, which the rolling element 33 first contacts, is greater than the pressing load of the rolling element 33 on the inner column portion 45, which the rolling element 33 contacts after the column portion 37 elastically deforms.

[0068] <Method of manufacturing cage> Next, a method for manufacturing the cage 34 will be described with reference to FIG. FIG. 7 is an explanatory diagram of a manufacturing method of the cage 34. As shown in Fig. 7, the cage 34 is injection molded using a mold 90. The 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 the cage 34. The first mold 91 shapes the outer peripheral surface 35b of the small diameter ring 35. The second mold 92 shapes the inner peripheral surface 36c of the large diameter ring 36.

[0069] Here, the outer diameter Φso of the small diameter ring 35 and the inner diameter Φbi of the large diameter ring 36 satisfy the above formula (1). Therefore, even when demolding is performed 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 makes it possible to form the pocket portion 41 of the cage 34 without providing a so-called slide core. A slide core is a mold that slides in a direction intersecting the axial direction.

[0070] Therefore, according to the above-described retainer 34, since it is injection molded from resin, the retainer 34 can be easily formed. When injection molding the retainer 34, the pocket portion 41 can be formed using only two molds 91, 92 that are separated in the axial direction (see the arrows in FIG. 7). This simplifies the structure of the mold 90 and facilitates the manufacture of the retainer 34. This in turn facilitates the manufacture of the eccentric portion bearing 19 and the reduction gear 1.

[0071] The pillar portions 37 of the cage 34 are formed with small-diameter-side inclined portions 46 and large-diameter-side inclined portions 47. Therefore, the small-diameter-side inclined portions 46 and the large-diameter-side inclined portions 47 can open the pocket portions 41 as large as possible. Therefore, even though both sides in the circumferential direction of the rolling elements 33 are surrounded by the pillar portions 37, oil permeability can be improved.

[0072] The column portion 37 is formed by integrally molding 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 each of the column portions 44, 45 when the reduction gear transmission 1 is in operation. This allows the load acting on the entire column portion 37 to be distributed to the outer column portion 44 and the inner column portion 45. As a result, it is possible to reduce the torsional load acting mainly on the joint between the outer peripheral surface 35b of the small diameter ring 35 and the outer column portion 44, and the torsional load acting mainly on the joint between the inner peripheral surface 36c of the large diameter ring 36 and the outer column portion 44. This allows the rigidity of the cage 34 to be increased.

[0073] Of the pressing loads of the rolling elements 33, the pressing load of the rolling elements 33 acting on the outer column portions 44 is greater than the pressing load of the rolling elements 33 acting on the inner column portions 45 with which the rolling elements 33 come into contact after the column portions 37 elastically deform. In this way, the pressing load of the rolling elements 33 acting on the outer column portions 44 is made different from the pressing load of the rolling elements 33 acting on the inner column portions 45. By adjusting the pressing loads of the rolling elements 33 acting on the column portions 44, 45, the rigidity of the cage 34 can be increased.

[0074] 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. The joining area between the large diameter ring 36 and the outer column portion 44 can also be made as large as possible. This makes it possible to increase the rigidity of the outer column portion 44 more than the rigidity of the inner column portion 45. The pressing load of the rolling elements 33 acting on the outer column portion 44, which has a relatively high rigidity, can be made larger than the pressing load of the rolling elements 33 acting on the inner column portion 45, which has a relatively low rigidity. This increases the load-bearing capacity of the cage 34 as a whole. This further increases the rigidity of the cage 34.

[0075] In order to differentiate the pressing load of the rolling element 33 acting on the outer column portion 44 from the pressing load of the rolling element 33 acting on the inner column portion 45, the timing at which the rolling element 33 contacts the outer column portion 44 and the timing at which the rolling element 33 contacts the inner column portion 45 are made slightly different. In order to differentiate these contact timings, when the rolling element 33 is in contact with the column portion 37 under no load, a minute gap is formed between the rolling element 33 and the side surface 45c of the inner column portion 45. In order to form this minute gap, when the rolling element 33 is in contact with the column portion 37 under no load, the straight line L passing through the center of the angle between the side surfaces 44c, 45c of the column portion 37 is shifted from the central axis C of the rolling element 33. With this configuration, it is possible to easily and reliably differentiate the pressing load of the rolling element 33 acting on the outer column portion 44 from the pressing load of the rolling element 33 acting on the inner column portion 45.

[0076] Both circumferential side surfaces 44c of the outer pillar portion 44 are inclined so that the circumferential thickness of the outer pillar portion 44 gradually increases radially outward. Both circumferential side surfaces 45c of the inner pillar portion 45 are inclined so that the circumferential thickness of the inner pillar portion 45 gradually increases radially inward. This allows the opening area of ​​the pocket portions 41 in the cage 34 to decrease radially outward and radially inward. This makes it possible to prevent the rolling elements 33 from coming out of the cage 34 with a simple structure.

[0077] In the above embodiment, a case has been described in which, when the rolling elements 33 are in contact with the column portions 37 of the cage 34 under no load, a minute gap is formed between the rolling elements 33 and the side surface 45c of the inner column portion 45. However, this is not limiting, and the column portions 37 may be formed as follows.

[0078] [First Modification] Fig. 8 is a side view of the column portion 37 in the first modified example, as viewed from the axial direction. Fig. 8 corresponds to Fig. 5 described above. For ease of understanding, Fig. 8 shows the small diameter ring 35 in a see-through manner. In the following description, the same reference numerals as in the above-described embodiment are used. The same applies to the second modified example described below. As shown in Figure 8, the pillar portion 37 may be formed so that, when the rolling element 33 is in contact with the pillar portion 37 without load, a straight line L passing through the center of the angle between the side surface 44c of the outer pillar portion 44 and the side surface 45c of the inner pillar portion 45 located on the same plane as the side surface 44c passes through the central axis C of the rolling element 33.

[0079] With this configuration, the rolling elements 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 points P1 and P2 in FIG. 8). Therefore, the load applied to the entire column portion 37 can be reliably distributed to the outer column portion 44 and the inner column portion 45. As a result, the torsional load applied mainly to the joint between the outer peripheral surface 35b of the small diameter ring 35 and the outer column portion 44, and the torsional load applied mainly to the joint between the inner peripheral surface 36c of the large diameter ring 36 and the outer column portion 44 can be reliably reduced. Therefore, the rigidity of the cage 34 can be increased.

[0080] [Second Modification] FIG. 9 is a side view of the pillar portion 37 in the second modified example, as viewed from the axial direction. As shown in Figure 9, the column portion 37 may be formed so that, when no load is applied, the rolling element 33 comes into contact between the outer surface 35b of the small diameter ring 35 and the inner surface 36c of the large diameter ring 36 at the column portion 37 when viewed from the axial direction (see point P3 in Figure 9).

[0081] The torsional load is generated mainly at the joint between the outer peripheral surface 35b of the small diameter ring 35 and the outer column portion 44 (see, for example, arrow F4 in FIG. 2). The torsional load is generated mainly at the joint between the inner peripheral surface 36c of the large diameter ring 36 and the outer column portion 44 (see, for example, arrow F5 in FIG. 3). Therefore, the rolling elements 33 are brought into contact with the column portion 37 between the outer peripheral surface 35b of the small diameter ring 35 and the inner peripheral surface 36c of the large diameter ring 36, as viewed from the axial direction. This minimizes the moment acting on the small diameter ring 35 and the large diameter ring 36 when a load is applied to the outer column portion 44 or the inner column portion 45. This reduces the torsional force, ensuring the rigidity of the cage 34.

[0082] [Third Modification] Fig. 10 is a perspective view of a part of the cage 34 in the third modified example, seen from the small diameter ring 35 side. Fig. 11 is a perspective view of a part of the cage 34 in the third modified example, seen from the large diameter ring 36 side. As shown in Figures 10 and 11, in the third modified example, the column portion 37 has a small diameter side inclined convex portion 51 formed on the small diameter side inclined portion 46 and a large diameter side inclined convex portion 52 formed on the large diameter side inclined portion 47.

[0083] The small diameter side inclined convex portion 51 extends radially over the entire small diameter side inclined portion 46. When viewed in the axial direction, the small diameter side inclined convex portion 51 extends radially. The small diameter side inclined convex portion 51 is formed so that its cross section along the circumferential and axial directions is triangular. In other words, the small diameter side inclined convex portion 51 is formed to taper so that its circumferential width gradually decreases as it extends radially outward.

[0084] The circumferential width W1 at the base of the small diameter side inclined convex portion 51 (hereinafter referred to as the width W1 of the small diameter side inclined convex portion 51) is smaller than the circumferential width W2 of the small diameter side inclined portion 46. This size relationship is the same throughout the radial direction of the small diameter side inclined convex portion 51 and the small diameter side inclined portion 46. The width W1 of the small diameter side inclined convex portion 51 gradually increases radially outward to correspond to the shape of the small diameter side inclined portion 46.

[0085] The large diameter side inclined convex portion 52 extends radially over the entire large diameter side inclined portion 47. When viewed from the axial direction, the large diameter side inclined convex portion 52 extends radially. The basic configuration of the large diameter side inclined convex portion 52 is the same as the basic configuration of the small diameter side inclined convex portion 51. In other words, the large diameter side inclined convex portion 52 is tapered so that its circumferential width gradually decreases as it extends radially outward.

[0086] The circumferential width W3 at the base of the large-diameter-side inclined convex portion 52 (hereinafter referred to as the width W3 of the large-diameter-side inclined convex portion 52) is smaller than the circumferential width W4 of the large-diameter-side inclined portion 47. This size relationship is the same throughout the radial direction of the large-diameter-side inclined convex portion 52 and the large-diameter-side inclined portion 47.

[0087] With this configuration, the lubricating oil that has entered the inside of the eccentric portion bearing 19 can be agitated by the small diameter side inclined convex portion 51 and the large diameter side inclined convex portion 52. More specifically, when the cage 34 is rotated, the lubricating oil inside the eccentric portion bearing 19 is scattered by the small diameter side inclined convex portion 51 and the large diameter side inclined convex portion 52. As the lubricating oil is scattered, new lubricating oil enters the inside of the eccentric portion bearing 19 from the outside.

[0088] Therefore, according to the third modified example described above, the small diameter side inclined convex portion 51 and the large diameter side inclined convex portion 52 can promote the lubrication of the lubricating oil at the eccentric portion bearing 19. Moreover, the width W1 of the small diameter side inclined convex portion 51 is smaller than the circumferential width W2 of the small diameter side inclined portion 46. The width W3 of the large diameter side inclined convex portion 52 is smaller than the circumferential width W4 of the large diameter side inclined convex portion 47. This reduces the flow resistance of the lubricating oil to the small diameter side inclined convex portion 51 and the large diameter side inclined convex portion 52. This makes it easier for the small diameter side inclined convex portion 51 and the large diameter side inclined convex portion 52 to splash the lubricating oil.

[0089] Furthermore, the small diameter side inclined convex portion 51 and the large diameter side inclined convex portion 52 are tapered so that their circumferential widths gradually decrease toward the radially outer side. This makes it possible to minimize the resistance to the separation of the lubricating oil from the small diameter side inclined convex portion 51 or the large diameter side inclined convex portion 52 when the lubricating oil is scattered from the small diameter side inclined convex portion 51 or the large diameter side inclined convex portion 52. As a result, the lubricating oil can be effectively scattered by the small diameter side inclined convex portion 51 or the large diameter side inclined convex portion 52.

[0090] [Fourth Modification] Fig. 12 is a perspective view of a part of the cage 34 in the fourth modified example, seen from the small diameter ring 35 side. Fig. 13 is a perspective view of a part of the cage 34 in the fourth modified example, seen from the large diameter ring 36 side. In the third modified example described above, the small diameter side inclined convex portion 51 extends along the radial direction as viewed from the axial direction. The large diameter side inclined convex portion 52 extends along the radial direction as viewed from the axial direction.

[0091] However, this is not limited to this, and as shown in Figures 12 and 13, the small diameter side inclined convex portion 51 and the large diameter side inclined convex portion 52 may extend in a direction that intersects with the radial direction when viewed from the axial direction. More specifically, small diameter side inclined convex portion 51 extends along a diagonal line of small diameter side inclined portion 46. Large diameter side inclined convex portion 52 extends along a diagonal line of large diameter side inclined portion 47.

[0092] With this configuration, when the cage 34 rotates, a radial component force acts on the lubricating oil pushed out by the small-diameter-side inclined convex portion 51 and the large-diameter-side inclined convex portion 52 (see, for example, arrow F8 in FIG. 12 and arrow F9 in FIG. 13). This causes the lubricating oil to flow in the radial direction. In addition to the same effect as the third modified example, this further promotes the stirring of the lubricating oil by the small-diameter-side inclined convex portion 51 and the large-diameter-side inclined convex portion 52.

[0093] In the third and fourth modified examples described above, the case where the small diameter side inclined convex portion 51 is formed on the small diameter side inclined portion 46 and the large diameter side inclined convex portion 52 is formed on the large diameter side inclined portion 47 has been described. However, this is not limited to this, and it is sufficient that at least one of the small diameter side inclined convex portion 51 or the large diameter side inclined convex portion 52 is formed on the cage 34.

[0094] In the third and fourth modified examples described above, the small diameter side inclined convex portion 51 and the large diameter side inclined convex portion 52 are described as being formed so that their circumferential and axial cross sections are triangular. However, this is not limited to this, and it is sufficient that at least the width W1 of the small diameter side inclined convex portion 51 is smaller than the circumferential width W2 of the small diameter side inclined portion 46. It is sufficient that the width W3 of the large diameter side inclined convex portion 52 is smaller than the circumferential width W4 of the large diameter side inclined portion 47.

[0095] It is desirable that each of the protrusions 51, 52 be tapered so that the circumferential width gradually decreases toward the radially outer side. In this case, the shape of each of the protrusions 51, 52 is not limited to a triangular cross section along the circumferential and axial directions. For example, each of the protrusions 51, 52 may be semicircular.

[0096] In the third and fourth modified examples described above, the protrusions 51, 52 extend over the entire radial extent of the corresponding inclined portions 46, 47. However, this is not limiting, and the protrusions 51, 52 may be formed only on a portion of the entire radial extent of the corresponding inclined portions 46, 47.

[0097] [Fifth Modification] FIG. 14 is a perspective view of a part of the cage 34 in the fifth modified example, seen from the small diameter ring 35 side. As shown in FIG. 14, in the column portion 37 of the fifth modified example, an end surface convex portion 53 is formed on the outer end surface 44b of the outer column portion 44. The end surface protrusion 53 extends over the entire axial direction of the outer end surface 44b. The end surface protrusion 53 is tapered so that its circumferential width decreases from the small diameter ring 35 toward the large diameter ring 36.

[0098] More specifically, the end surface protrusion 53 has a parallel side surface 53a formed on one of the two circumferential side surfaces and aligned along the side surface 44c of the outer pillar portion 44. The end surface protrusion 53 has an inclined side surface 53b formed on the other of the two circumferential side surfaces and inclined relative to the side surface 44c of the outer pillar portion 44. The end surface protrusions 53 are arranged side by side in the circumferential direction such that the circumferential orientations of the parallel side surfaces 53a and the inclined side surfaces 53b alternate.

[0099] With this configuration, the lubricating oil that has entered the inside of the eccentric portion bearing 19 can be agitated by the end surface convex portions 53. More specifically, when the cage 34 is rotated, the end surface convex portions 53 scatter the lubricating oil inside the eccentric portion bearing 19. As the lubricating oil is scattered, new lubricating oil enters the inside of the eccentric portion bearing 19 from the outside. Therefore, the fifth modified example described above has the same effect as the third modified example described above.

[0100] The end surface protrusions 53 have inclined side surfaces 53b that are inclined relative to the side surfaces 44c of the outer pillar portions 44. Therefore, when the cage 34 rotates, a component force acts in the axial direction on the lubricating oil pushed out by the end surface protrusions 53. Therefore, the same effect as in the fourth modified example described above is achieved. Moreover, the end surface protrusions 53 are arranged in a line in the circumferential direction so that the circumferential orientations of the parallel side surfaces 53a and the inclined side surfaces 53b are staggered. Therefore, regardless of the rotation direction of the cage 34, a flow of lubricating oil along the axial direction is generated by one of the inclined side surfaces 53b of any one of the end surface protrusions 53. This reliably promotes agitation of the lubricating oil.

[0101] [Sixth Modification] FIG. 15 is a perspective view of a part of the cage 34 in the sixth modified example, seen from the small diameter ring 35 side. In the fifth modified example described above, the end surface protrusion 53 has been described as having parallel side surfaces 53a and inclined side surfaces 53b. However, this is not limited to this, and the end surface protrusion 53 may be formed in an isosceles triangular shape when viewed from the radial direction, as shown in Fig. 15. That is, the end surface protrusion 53 in the sixth modified example has a pair of inclined side surfaces 53c formed on both circumferential side surfaces and inclined with respect to the side surfaces 44c of the outer pillar portion 44. Therefore, the sixth modification described above provides the same effects as the fifth modification described above.

[0102] [Seventh Modification] FIG. 16 is a perspective view of a part of the cage 34 in the seventh modified example, seen from the small diameter ring 35 side. The seventh modified example differs from the fifth modified example described above in that the shape of the inclined side surface 53b in the fifth modified example is different from the shape of the inclined side surface 54 in the seventh modified example. More specifically, the inclined side surface 54 of the seventh modified example has two inclined side surfaces 54a, 54b (first inclined side surface 54a and second inclined side surface 54b) with different inclination angles. Of the two inclined side surfaces 54a, 54b, the first inclined side surface 54a is disposed on the small-diameter ring 35 side. Of the two inclined side surfaces 54a, 54b, the second inclined side surface 54b is disposed between the first inclined side surface 54a and the end of the outer end surface 44b on the large-diameter ring 36 side.

[0103] The inclination angle θ3 of the first inclined side surface 54a relative to the side surface 44c of the outer pillar 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 pillar portion 44. On the outer end surface 44b, the area where the second inclined side surface 54b is formed is larger than the area where the first inclined side surface 54a is formed.

[0104] Therefore, the seventh modification achieves the same effects as the fifth modification. In addition, the inclined side surface 54 of the seventh modification has two inclined side surfaces 54a and 54b with different inclination angles. This makes it easier for the first inclined side surface 54a to scoop in a larger amount of lubricant. The lubricant scooped in by the first inclined side surface 54a can be made to flow in the axial direction by the second inclined side surface 54b. This allows the lubricant to be stirred more effectively.

[0105] In the fifth to seventh modified examples described above, the end surface protrusions 53 have been described as extending over the entire axial direction of the outer end face 44b. The end surface protrusions 53 have been described as tapering so that their circumferential width decreases from the small-diameter ring 35 to the large-diameter ring 36. However, the shape of the end surface protrusions 53 is not limited to the above. The end surface protrusions 53 may be formed on a portion of the entire axial direction of the outer end face 44b. The end surface protrusions 53 may be formed in a rod shape with a uniform circumferential width when viewed radially. The end surface protrusions 53 may be tapered so that their circumferential width gradually decreases radially outward.

[0106] [Eighth Modification] FIG. 17 is a perspective view of a part of the cage 34 in the eighth modified example, seen from the small diameter ring 35 side. 17, a plurality of inner small diameter recesses 55 are formed on the opposing surface 35a of the small diameter ring 35 in the eighth modified example. A plurality of inner large diameter recesses 56 are formed on the opposing surface 36a of the large diameter ring 36.

[0107] Each recess 55, 56 is disposed in the circumferential center between two circumferentially adjacent pillar portions 37. Therefore, each inner small diameter recess 55 is spaced apart from the connection portion (rounded corner) between the small diameter ring 35 and the pillar portion 37. Each inner large diameter recess 56 is spaced apart from the connection portion (rounded corner) between the large diameter ring 36 and the pillar portion 37.

[0108] Each recess 55, 56 is formed so that its cross section along the circumferential direction is U-shaped. 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.

[0109] Therefore, according to the above-described eighth modified example, the flow of lubricating oil in the pocket portion 41 can be promoted via the recesses 55, 56. Moreover, the recesses 55, 56 are formed over the entire radial length of the corresponding rings 35, 36. This allows the lubricating oil to smoothly flow in and out of the radial length of the rings 35, 36 via the recesses 55, 56. This promotes the lubrication of the lubricating oil in the eccentric portion bearing 19.

[0110] [Ninth Variation] Fig. 18 is a perspective view of a part of the cage 34 in the ninth modified example, seen from the small diameter ring 35 side. Fig. 19 is a perspective view of a part of the cage 34 in the ninth modified example, seen from the large diameter ring 36 side. In the above-described eighth modified example, a case has been described in which a plurality of inner small diameter recesses 55 are formed in the opposing surface 35a of the small diameter ring 35. A case has been described in which a plurality of inner large diameter recesses 56 are formed in the opposing surface 36a of the large diameter ring 36. However, this is not limiting, and in addition to the inner small diameter recesses 55, a plurality of outer small diameter recesses 57 may be formed in the outer end surface 35d of the small diameter ring 35 as shown in FIG. 18. In addition to the inner large diameter recesses 56, a plurality of outer large diameter recesses 58 may be formed in the outer end surface 36d of the large diameter ring 36 as shown in FIG. 19.

[0111] Two outer small diameter recesses 57 are arranged between each pair of circumferentially adjacent pillar portions 37. In other words, the two outer small diameter recesses 57 are arranged between each pair of circumferentially adjacent pillar portions 37, and on both sides of the inner small diameter recess 55 when viewed from the axial direction. In other words, the inner small diameter recesses 55 and the outer small diameter recesses 57 are arranged alternately.

[0112] The outer large diameter recesses 58 are arranged in the same manner as the outer small diameter recesses 57. That is, two outer large diameter recesses 58 are arranged between each pair of circumferentially adjacent pillar portions 37. In other words, the two outer large diameter recesses 58 are arranged between each pair of circumferentially adjacent pillar portions 37, and on both sides of the inner large diameter recess 56 when viewed from the axial direction.

[0113] The outer small diameter recess 57 and the outer large diameter recess 58 are formed so that their circumferential cross sections have a U-shape. The outer small diameter recess 57 and the outer large diameter recess 58 are formed over the entire radial length of the corresponding rings 35, 36. 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.

[0114] Therefore, according to the ninth modification, in addition to the same effects as those of the eighth modification, the lubrication of the lubricating oil at the eccentric portion bearing 19 can be further promoted.

[0115] In the eighth and ninth modified examples described above, the recesses 55-58 are each formed so that their cross-sectional shape along the circumferential direction is U-shaped. However, this is not limited to this, and the recesses 55-58 can be formed in various shapes. For example, the recesses 55-58 may be formed so that their cross-sectional shape along the circumferential direction is V-shaped. However, it is desirable that the recesses 55-58 are formed over the entire radial direction of the corresponding rings 35, 36.

[0116] In the eighth modified example described above, the small diameter ring 35 is formed with the inner small diameter recess 55, and the large diameter ring 36 is formed with the inner large diameter recess 56. In the ninth modified example described above, in addition to the inner small diameter recess 55 and the inner large diameter recess 56, the small diameter ring 35 is formed with the outer small diameter recess 57, and the large diameter ring 36 is formed with the outer large diameter recess 58. However, this is not limited to this, and it is sufficient that at least one of the recesses 55 to 58 is formed in either the small diameter ring 35 or the large diameter ring 36. Even with this configuration, the lubrication of the lubricating oil in the eccentric portion bearing 19 can be promoted.

[0117] [Tenth Modification] Fig. 20 is a perspective view of the crankshaft 13 and the eccentric bearing 19 in the tenth modified example, as viewed from the side of the base plate 7. For ease of understanding, Fig. 20 shows the crank bearing 18 on the side of the base plate 7 removed. As described above, the retainer 34 is injection molded using the mold 90. At this time, an ejector pin (not shown) is used to remove the molded retainer 34 from the mold 90. The ejector pin ejects the retainer 34 in the mold release direction of the mold 90, thereby removing the retainer 34 from the mold 90.

[0118] 20, a plurality of ejector pin marks M are formed on the cage 34 due to protrusion by the ejector pins. The ejector pin marks M are 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 to the opposing surface (outer end surface 36d of the large diameter ring 36) of the axially adjacent cages 34. No ejector pin marks M are formed on the outer end surface 36d of the large diameter ring 36.

[0119] Incidentally, the outer end surfaces 36d of the large diameter rings 36 of the axially adjacent cages 34 rub against each other as the reduction gear device 1 is driven. If ejector pin marks M are formed on such surfaces, there is a possibility that the cages 34 may be damaged by burrs generated in the ejector pin marks M. There is also a possibility that the burrs may break off and become foreign matter and remain inside the reduction gear device 1.

[0120] On the other hand, the outer end surface 35d of the small diameter ring 35 only comes into contact with 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 rings 36. Therefore, according to the above-described tenth modification, in addition to achieving the same effects as the above-described embodiment, damage to the cage 34 can be prevented and foreign matter can be prevented from entering the reduction gear transmission 1.

[0121] In the above-described tenth modified example, the case where the ejector pin marks M are formed on the outer end surface 35d of the small diameter ring 35 has been described. However, this is not limited to this, and the location where the ejector pin marks M are formed may be changed depending on the mounting orientation of the cage 34. In other words, the ejector pin marks M are formed on the opposite side of the surfaces of the axially adjacent cages 34 that face each other. More specifically, when the axially adjacent cages 34 are mounted such that the small diameter ring 35 sides face each other, the cages 34 are injection molded so that the ejector pin marks M are formed on the outer end surface 36d of the large diameter ring 36.

[0122] [Eleventh Modification] 21 is a partially enlarged view of a cross section taken along the axial direction of the large diameter ring 36 in the eleventh modified example. Fig. 21 corresponds to the enlarged view of part XXI in Fig. 1. As shown in FIG. 21, the large diameter ring 36 of the cage 34 has rounded chamfered portions 36e formed on the outer peripheral edge and inner peripheral edge of the outer end face 36d.

[0123] As described above, the outer end faces 36d of the large diameter rings 36 of the axially adjacent cages 34 rub against each other as the reduction gear transmission 1 is driven. At this time, if the outer and inner peripheral edges of the outer end faces 36d are sharp, the peripheral edges of the large diameter rings 36 may get caught on each other, potentially damaging the cages 34. However, by forming rounded chamfered portions 36e on the outer and inner peripheral edges of the outer end face 36d, the peripheral edges of the large diameter rings 36 can be brought into smooth contact with each other, preventing the retainers 34 from damaging each other.

[0124] [12th Modification] 22 is a partially enlarged cross-sectional view taken along the axial direction of the large diameter ring 36 in the twelfth modified example. FIG. 22 corresponds to the above-mentioned FIG. In the eleventh modified example described above, the rounded chamfered portions 36e are formed on the outer and inner peripheral edges of the outer end surface 36d of the large diameter ring 36. However, this is not limited to this, and as shown in Fig. 22, the outer end surface 36d may be entirely curved so as to be convex toward each of the large diameter rings 36. Even in such a configuration, the same effects as those of the eleventh modified example described above can be achieved.

[0125] In the above-described eleventh modified example, the rounded chamfered portions 36e are formed on the outer peripheral edge and the inner peripheral edge of the outer end surface 36d of the large diameter ring 36. In the above-described twelfth modified example, the entire outer end surface 36d of the large diameter ring 36 is curved. However, this is not limiting, and the locations where the rounded chamfered portions 36e are formed and the locations where the curves are formed may be changed depending on the mounting orientation of the cage 34.

[0126] In other words, the surfaces of the axially adjacent cages 34 facing each other may be curved or rounded and chamfered. More specifically, when the axially adjacent cages 34 are attached so that the small diameter rings 35 thereof face each other, rounded and chamfered portions may be formed on the outer and inner peripheral edges 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 curved.

[0127] [13th Modification] 23 is a partially enlarged axial cross-sectional view of the cage 34 in the thirteenth modified example, which corresponds to the enlarged view of part XXIII in FIG. 23, the axial thickness T1 of the large diameter ring 36 (hereinafter simply referred to as thickness T1) is greater than the axial thickness T2 of the small diameter ring 35 (hereinafter simply referred to as thickness T2). Therefore, the rigidity of the large diameter ring 36 can be increased relative to the small diameter ring 35 without changing the axial length of the cage 34.

[0128] As described above, the outer end surfaces 36d of the large diameter rings 36 of the axially adjacent cages 34 rub against each other as the reduction gear transmission 1 is driven. This places a load on the large diameter rings 36, which could result in deformation or damage to the large diameter rings 36. By increasing the rigidity of the large diameter rings 36 that rub against each other compared to the small diameter rings 35, deformation and damage to the large diameter rings 36 can be suppressed.

[0129] In the above-described thirteenth modified example, the case where the thickness T1 of the large diameter ring 36 is formed to be thicker than the thickness T2 of the small diameter ring 35 has been described. However, this is not limited to this, 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 cage 34. For example, when adjacent cages 34 in the axial direction are mounted so that the small diameter rings 35 face each other, the thickness T2 of the small diameter ring 35 may be formed to be thicker than the thickness T1 of the large diameter ring 36. The specific difference between the thicknesses T1 and T2 may be determined depending on the load applied to the large diameter ring 36 or the small diameter ring 35 rubbing against each other.

[0130] [14th Modification] Fig. 24 is a perspective view of a portion of the cage 34 in the fourteenth modified example, seen from the small diameter ring 35 side. Fig. 24 corresponds to the enlarged view of part XXIV in Fig. 2 described above. Fig. 25 is a perspective view of a portion of the cage 34 in the fourteenth modified example, seen from the large diameter ring 36 side. Fig. 25 corresponds to the enlarged view of part XXV in Fig. 3 described above. 24, the pillar portions 37 of the cage 34 have small-diameter-side rounded chamfered portions 46a formed at the connection portions with the small-diameter ring 35. More specifically, the pillar portions 37 have small-diameter-side rounded chamfered portions 46a formed at the corners between the small-diameter-side inclined portions 46 and both side surfaces 44c of the outer pillar portions 44.

[0131] As a result, a small diameter side rounded chamfered portion 46a is formed in the column portion 37 at the connection portion with the outer peripheral surface 35b of the small diameter ring 35. The small diameter side rounded chamfered portion 46a is formed in an arc shape. The small diameter side rounded chamfered portion 46a can prevent stress from concentrating at this connection portion compared to when the connection portion between the column portion 37 and the outer peripheral surface 35b of the small diameter ring 35 is angular.

[0132] 25, the pillar portions 37 of the cage 34 have large-diameter-side rounded chamfered portions 47a formed at the connection portions with the large-diameter ring 36. More specifically, the pillar portions 37 have large-diameter-side rounded chamfered portions 47a formed at the corners between the large-diameter-side inclined portions 47 and the side surfaces 44c of the outer pillar portions 44 and the side surfaces 45c of the inner pillar portions 45.

[0133] As a result, a large-diameter-side rounded chamfered portion 47a is formed in the column portion 37 at the connection portion with the inner peripheral surface 36c of the large-diameter ring 36. The large-diameter-side rounded chamfered portion 47a is formed in an arc shape. Compared to when the connection portion between the column portion 37 and the inner peripheral surface 36c of the large-diameter ring 36 is angular, the large-diameter-side rounded chamfered portion 47a can prevent stress from concentrating at this connection portion.

[0134] Therefore, according to the above-described fourteenth modification, stress concentration on the cage can be alleviated by the small diameter side rounded chamfered portion 46a and the large diameter side rounded chamfered portion 47a, and damage to the cage can be prevented.

[0135] [15th Modification] Fig. 26 is a perspective view of a portion of the cage 34 in the fifteenth modified example, seen from the small diameter ring 35 side. Fig. 26 corresponds to the above-mentioned Fig. 24. Fig. 27 is a perspective view of a portion of the cage 34 in the fourteenth modified example, seen from the large diameter ring 36 side. Fig. 27 corresponds to the above-mentioned Fig. 25.

[0136] 26 and 27, the difference between the above-described 14th and 15th modified examples is that in the 14th modified example, a small diameter side rounded chamfered portion 46a and a large diameter side rounded chamfered portion 47a are formed on the base portion 37, whereas in the 15th modified example, a small diameter side flat chamfered portion 46b and a large diameter side flat chamfered portion 47b are formed on the base portion 37 instead of the small diameter side rounded chamfered portion 46a and the large diameter side rounded chamfered portion 47a. Each of the flat chamfered portions 46b, 47b is formed flat. Even in this configuration, the same effects as those of the above-described fourteenth modification example are achieved.

[0137] Furthermore, the present invention is not limited to the above-described embodiments, and includes various modifications to the above-described embodiments without departing from the spirit of the present invention.

[0138] For example, in the above embodiment, an eccentric oscillating type reduction gear 1 has been described as an example of a rotating device, and an eccentric portion bearing 19 has been provided in this reduction gear 1. However, this is not limited to this, and the configuration of the eccentric portion bearing 19 can be adopted for the bearing in various rotating devices that use bearings. It is not necessary for the inner ring 31 to be integrally molded with the eccentric portions 13a, 13b, or for the outer ring 32 to be integrally molded with the oscillating external gears 15, 16. The configuration of the eccentric portion bearing 19 can be adopted as a bearing alone.

[0139] In the above embodiment, the eccentric bearing 19 is a so-called needle bearing. However, this is not limiting, and the configuration of the eccentric bearing 19 can be used in various bearings that have rolling elements. For example, the configuration of the cage 34 can also be used in a deep groove ball bearing.

[0140] In the above embodiment, the reduction gear 1 is an eccentric oscillating reduction gear having a plurality of (for example, three) crankshafts 13. However, this is not limiting, and this type of reduction gear may have only one crankshaft 13. In this case, the crankshaft 13 is disposed coaxially with the first rotation axis A1.

[0141] In the above embodiment, the reduction gear 1 has been described as having two oscillating external gears 15, 16. However, this is not limited to this, and it is sufficient to have at least one oscillating external gear. It may also be possible to have three or more oscillating external gears. The number of eccentric portions may be changed depending on the number of oscillating external gears. Even with this configuration, it is possible to fulfill the function of an eccentric oscillating type reduction gear.

[0142] In the above-described embodiment, the radial width Wo of the large diameter ring 36 is larger than the radial width Ws of the small diameter ring 35. However, this is not limited to this, and the radial width Wo of the large diameter ring 36 and the radial width Ws of the small diameter ring 35 can be determined arbitrarily. For example, the radial width Ws of the small diameter ring 35 may be larger than the radial width Wo of the large diameter ring 36. In this case, it is desirable to form the column portions 37 so that the pressing load of the rolling elements 33 acting on the inner column portions 45 is larger than the pressing load of the rolling elements 33 acting on the outer column portions 44.

[0143] In the above embodiment, the case where the small diameter side inclined portion 46 and the large diameter side inclined portion 47 are formed on the pillar portion 37 of the cage 34 has been described. However, this is not limited to this, and it is sufficient that at least one of the small diameter side inclined portion 46 and the large diameter side inclined portion 47 is formed on the pillar portion 37. Even in such a case, oil permeability can be improved compared to a case where the inclined portions 46, 47 are not formed.

[0144] In the above embodiment, the case has been described in which both circumferential side surfaces 44c of the outer pillar portion 44 are inclined so that the circumferential thickness of the outer pillar portion 44 gradually increases radially outward. The case has been described in which both circumferential side surfaces 45c of the inner pillar portion 45 are inclined so that the circumferential thickness of the inner pillar portion 45 gradually increases radially inward. However, this is not limited to this, and the shape of the pillar portion 37 can be determined as desired.

[0145] However, when the pillar portion 37 is configured by an outer pillar portion 44 and an inner pillar portion 45, the pillar portion 37 is formed so that the rolling element 33 comes into contact with the outer pillar portion 44 and the inner pillar portion 45 when the reduction gear device 1 is driven.

[0146] The column portion 37 does not have to be composed of the outer column portion 44 and the inner column portion 45. In this case, the column portion 37 may be formed so that, when no load is applied, the rolling elements 33 come into contact between the outer peripheral surface 35b of the small diameter ring 35 and the inner peripheral surface 36c of the large diameter ring 36 at the column portion 37 as viewed from the axial direction. More preferably, the column portion 37 should be formed so that, from the time when no load is applied until the time when the reduction gear device 1 is being driven, the rolling elements 33 always come into contact between the outer peripheral surface 35b of the small diameter ring 35 and the inner peripheral surface 36c of the large diameter ring 36 at the column portion 37 as viewed from the axial direction.

[0147] Among the embodiments disclosed in this specification, those that are comprised of multiple objects may be integrated, and conversely, those that are comprised of a single object may be separated into multiple objects. Regardless of whether they are integrated, it is sufficient that they are configured to achieve the object of the invention. [Explanation of symbols]

[0148] 1...Reduction gear (rotating gear) 2. Case 3. Career 5...Inner tooth pin (inner tooth) 6...Main bearing (first rolling bearing) 13...Crankshaft (rotating body) 13a...First eccentric part (eccentric part) 13b...Second eccentric part (eccentric part) 13c...shaft body 15...First oscillating external gear (oscillating external gear) 16... Second oscillating external gear (oscillating external gear) 19...Eccentric bearing (rolling bearing, second rolling bearing) 31...Inner circle 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 surface 36...Large diameter ring 36a... Opposing surface (surface of the large diameter ring facing the small diameter ring) 36c…Inner peripheral surface 37...Column part 44…Outer column part 44c…Side (outer side) 45...Inner column part 45c…Side (inner side) 46…Small diameter side inclined part 47...Large diameter side inclined section 51...Small diameter side inclined convex portion (inclined convex portion) 52...Large diameter side inclined convex portion (inclined convex portion) 53...Convex end 53b, 53c, 54...Slanted side 55...Inner small diameter recess (recess) 56...Inner large diameter recess (recess) 57...Outer small diameter recess (recess) 58...External large diameter recess (recess) C…Central axis L…straight line

Claims

1. A cage for holding a plurality of rolling elements of a rolling bearing having a plurality of rolling elements arranged in a circumferential direction, an annular small diameter ring; a large diameter ring annularly disposed axially apart from the small diameter ring; a plurality of pillar portions extending in a radial direction so as to connect the small diameter ring and the large diameter ring and disposed between the rolling elements adjacent to each other in the circumferential direction; Equipped with 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 are Φso≦Φbi fulfill, retainer.

2. a small diameter side inclined portion is formed at a corner portion of the column portion on the small diameter ring side and located radially outward from the small diameter ring, The small diameter side inclined portion is inclined so as to gradually move radially inward as it approaches the small diameter ring in the axial direction. The cage of claim 1 .

3. a large-diameter-side inclined portion is formed at a corner of the column portion on the large-diameter ring side and located radially inward of the large-diameter ring, The large-diameter-side inclined portion is inclined so as to gradually move radially outward as it approaches the large-diameter ring in the axial direction. The cage of claim 1 .

4. At least one of a small diameter side inclined portion and a large diameter side inclined portion is formed on the pillar portion, the small-diameter-side inclined portion is disposed at a corner portion located on the small-diameter ring side and radially outward of the small-diameter ring, and is inclined so as to gradually move radially inward as it approaches the small-diameter ring in the axial direction, The large-diameter-side inclined portion is disposed at a corner portion located on the large-diameter ring side and radially inward of the large-diameter ring, and is inclined so as to gradually move radially outward as it approaches the large-diameter ring in the axial direction. The cage of claim 1 .

5. an inclined convex portion is formed on at least one of the small diameter side inclined portion and the large diameter side inclined portion, a circumferential width of the inclined convex portion is smaller than a circumferential width of the small diameter side inclined portion or the large diameter side inclined portion on which the inclined convex portion is formed; The cage according to claim 4.

6. The inclined convex portion extends along the radial direction when viewed from the axial direction. The cage according to claim 5 .

7. The inclined convex portion extends in a direction intersecting with the radial direction when viewed from the axial direction. The cage according to claim 5 .

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

9. The end surface convex portion is formed so that its circumferential width decreases from the small diameter ring toward the large diameter ring. The cage of claim 8.

10. At least one of the large diameter ring and the small diameter ring has a recess formed on an end surface in the axial direction and between two of the column portions adjacent in the circumferential direction. The cage according to claim 4.

11. The recess is formed over the entire radial direction of at least one of the large diameter ring and the small diameter ring. The cage of claim 10.

12. The pillar portion is integrally formed with an outer pillar portion disposed on the radially outer side and an inner pillar portion disposed on the radially inner side, The outer column portion and the inner column portion are each formed to come into contact with the rolling element. The cage of claim 1 .

13. The outer column portion and the inner column portion are formed so that a load pressing the outer column portion by the rolling element is different from a load pressing the inner column portion by the rolling element. The cage of claim 12.

14. the outer column portion extends from a surface of the large diameter ring facing the small diameter ring to the small diameter ring, the inner pillar portion extends from a 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 joined to the ring having a larger radial width out of the large diameter ring or the small diameter ring is greater than the load applied to the outer column portion or the inner column portion joined to the ring having a smaller radial width, The cage of claim 13.

15. Both 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 outside in the radial direction, Both circumferential side surfaces of the inner pillar portion are formed to be inclined so that the plate thickness of the inner pillar portion gradually increases toward the inside in the radial direction. A cage according to any one of claims 12 to 14.

16. When the rolling elements are in contact with the column portions under no load, a straight line passing through the center of an angle between one of the outer side surfaces of the outer column portion and one of the inner side surfaces of the inner column portion that is on the same plane as the outer side surface is deviated from the central axis of the rolling elements. The cage of claim 15.

17. The column portion is formed so as to come into contact with the rolling elements 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. The cage of claim 1 .

18. With inner circle, 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 aligned in a circumferential direction; a cage that holds the plurality of rolling elements; Equipped with The retainer is an annular small diameter ring; a large diameter ring annularly disposed axially apart from the small diameter ring; a plurality of pillar portions extending in a radial direction so as to connect the small diameter ring and the large diameter ring and disposed between the rolling elements adjacent to each other in the circumferential direction; Equipped with 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 are Φso≦Φbi fulfill, Rolling bearing.

19. a case having an internal gear; a carrier rotatably supported by the case; a shaft body rotatably supported by the carrier via a first rolling bearing, and at least one crankshaft provided on the shaft body and having an eccentric portion eccentric with respect to a rotation axis of the shaft body; an oscillating external gear that is rotatably supported by the eccentric portion via a second rolling bearing and that meshes with the internal gear; Equipped with The second rolling bearing comprises: With inner circle, 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 aligned in a circumferential direction; a cage that holds the plurality of rolling elements; Equipped with The retainer is an annular small diameter ring; a large diameter ring annularly disposed axially apart from the small diameter ring; a plurality of pillar portions extending in a radial direction so as to connect the small diameter ring and the large diameter ring and disposed between the rolling elements adjacent to each other in the circumferential direction; Equipped with 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 are Φso≦Φbi fulfill, Rotating device.

Images