Rotating device

Abstract

The invention relates to a rotating device. A reduction gear (1) according to one embodiment of the present invention is provided with an eccentric bearing (19), a crankshaft (13) into which the eccentric bearing (19) is fitted, and oscillating gears (15, 16). An eccentric bearing (19) is provided with: an inner ring (31); an outer ring (32) disposed on the outside in the radial direction of the inner ring (31); a plurality of rolling bodies (33) disposed between the inner ring (31) and the outer ring (32); and a holder (34) that holds the plurality of rolling bodies (33). The cage (34) has an inner flange section (38) and an outer flange section (39) formed so as to protrude further outward in the axial direction than the axial end of at least one of the inner ring (31) and the outer ring (32). The inner flange section (38) and the outer flange section (39) overlap with the inner ring (31) and the outer ring (32) as viewed in the axial direction.

Description

Technical Field

[0001] The present invention relates to a rotating device. Background Art

[0002] Among rotating devices, there are, for example, reduction gears that receive rotation from an electric motor or the like and decelerate or accelerate the rotation to output it. Among reduction gears, there are, for example, eccentric oscillating reduction gears that have high rotational position accuracy and load resistance. Such reduction gears include, for example: a housing having an internal gear formed on its inner circumference; an oscillating gear (planetary gear) that meshes with the internal gear and oscillates; a crankshaft (eccentric shaft) having an eccentric portion that supports the oscillating gear so that it can rotate freely and transmits rotational force to the oscillating gear; and a gear frame (gear frame flange, output flange) that supports the crankshaft so that it can rotate freely and transmits the rotational force of the oscillating gear.

[0003] The crankshaft has main bearings (first and second bearings) axially outward from the eccentric portion, which are rotatably supported on the gear carrier. The eccentric portion is provided with an eccentric bearing (eccentric bearing) to rotatably support the swing gear. These bearings include an inner ring; an outer ring positioned radially outward of the inner ring; multiple rolling elements positioned between the inner and outer rings; and a retainer to retain the rolling elements. Some eccentric bearings have an inner ring and eccentric portion integrally formed for structural simplicity (see, for example, Patent Document 1).

[0004] This eccentric bearing includes a spacer disposed between the main bearing and the eccentric bearing. The spacer functions as a pressure member for the retainer in the eccentric bearing. As a result, the position of the rolling elements retained in the retainer is restricted (see, for example, Patent Document 1).

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2023-55060 Summary of the Invention

[0008] Problems to be solved by the invention

[0009] When spacers are used to restrict the positions of rolling elements as in the above-mentioned conventional technology, there is a problem that the number of components increases and the structure becomes complicated.

[0010] The present invention provides a rotation device capable of regulating the position of a rolling element with a simple structure.

[0011] Solutions for solving problems

[0012] A rotating device according to one technical solution of the present invention comprises: a bearing; and a rotating body in which the bearing is fitted, the bearing comprising: an inner ring; an outer ring arranged radially outside the inner ring; a plurality of rolling elements arranged between the inner ring and the outer ring; and a retainer which retains the plurality of rolling elements, the retainer having a convex portion protruding axially outward from an axial end portion of at least either one of the inner ring and the outer ring, the convex portion overlapping with at least either one of the inner ring and the outer ring when viewed axially.

[0013] This configuration allows the convex portion to restrict the position of the retainer relative to the inner and outer rings. Consequently, the position of the rolling elements can be restricted. This eliminates the need for spacers or other components other than bearings to restrict the position of the rolling elements, simplifying the structure of the rotating device.

[0014] In the above structure, the retainer may also include: an annular small-diameter ring; an annular large-diameter ring, which is arranged on the radially outer side of the small-diameter ring; and a column portion, which extends radially in a manner connecting the small-diameter ring and the large-diameter ring, and the convex portion includes an inner flange portion protruding radially inward from the small-diameter ring, and the inner diameter of the inner flange portion is smaller than the outer diameter of the inner ring.

[0015] In the above structure, the retainer may also include: an annular small-diameter ring; an annular large-diameter ring, which is arranged radially outward of the small-diameter ring; a column portion, which extends radially in a manner connecting the small-diameter ring and the large-diameter ring, and the convex portion includes an outer flange portion protruding radially outward from the large-diameter ring, and the outer diameter of the outer flange portion is larger than the inner diameter of the outer ring.

[0016] In the above structure, it can also be that the rotating device includes: a housing having an internal gear; a gear frame supported on the housing in a rotatable manner; a shaft body and at least one crankshaft, the shaft body being supported on the gear frame in a rotatable manner by means of other bearings, and the at least one crankshaft being arranged on the shaft body; and a swinging gear meshing with the internal gear, the crankshaft having an eccentric portion that is eccentric relative to the rotation axis of the shaft body, the swinging gear being supported on the eccentric portion in a rotatable manner by means of the bearing, the inner ring being integrated with the eccentric portion, and the convex portion overlapping with the inner ring when viewed axially.

[0017] In the above configuration, the convex portion may be arranged between the other bearing and the eccentric portion.

[0018] In the above configuration, the rotating device may include a recessed portion formed on an outer peripheral surface of the crankshaft, and the convex portion may be arranged in the recessed portion.

[0019] In the above structure, it can also be that the rotating device includes: a housing having an internal gear; a gear frame supported on the housing in a rotatable manner; a shaft body and at least one crankshaft, the shaft body being supported on the gear frame in a rotatable manner by means of other bearings, and the at least one crankshaft being arranged on the shaft body; and a swinging gear meshing with the internal gear, the crankshaft having an eccentric portion that is eccentric relative to the rotation axis of the shaft body, the swinging gear being supported on the eccentric portion in a rotatable manner by means of the bearing, the outer ring being integrated with the swinging gear, and the convex portion overlapping with the outer ring when viewed axially.

[0020] In the above configuration, the rotating device may include a plurality of the oscillation gears, and the convex portion may be arranged between the oscillation gears adjacent to each other in the axial direction.

[0021] In the above configuration, the holder may be formed of resin.

[0022] The rotating device of another technical solution of the present invention comprises: a housing having an internal gear; a gear frame supported by the housing in a rotatable manner; a shaft body and at least one crankshaft, the shaft body being supported by the gear frame in a rotatable manner, the at least one crankshaft being arranged on the shaft body; and a swinging gear meshing with the internal gear, the crankshaft having an eccentric portion eccentric with respect to the rotation axis of the shaft body, the swinging gear being supported by the eccentric portion in a rotatable manner by means of a bearing, the bearing comprising: an inner ring; an outer ring, which is arranged on the radial outer side of the inner ring side; a plurality of rolling elements, which are arranged between the inner ring and the outer ring; and a retainer, which retains the plurality of rolling elements, the retainer comprising: an annular small-diameter ring; an annular large-diameter ring, which is arranged radially outside the small-diameter ring; a column portion, which extends radially in a manner connecting the small-diameter ring and the large-diameter ring; and a convex portion, which protrudes axially outward from at least any one of the small-diameter ring and the large-diameter ring than the axial end of at least any one of the inner ring and the outer ring, and the convex portion overlaps with at least any one of the inner ring and the outer ring when viewed from the axial direction.

[0023] With this configuration, in the eccentric oscillating speed reducer, the position of the rolling element can be regulated with a simple structure.

[0024] Effects of the Invention

[0025] The above-mentioned rotating device can regulate the position of the rolling element with a simple structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a cross-sectional view of a reduction gear transmission in an embodiment of the present invention.

[0027] Figure 2 yes Figure 1 Enlarged view of Part II.

[0028] Figure 3 It is a perspective view of a cross section of the cage according to the embodiment of the present invention along the axial direction.

[0029] Figure 4 It is a perspective view of a cross section along the axial direction of a cage according to a first modified example of the embodiment of the present invention.

[0030] Figure 5 It is a perspective view of a cross section along the axial direction of a cage according to a second modified example of the embodiment of the present invention.

[0031] Description of Reference Numerals

[0032] 1. Speed ​​reduction device (rotating device); 2. Housing; 3. Gear rack; 5. Internal tooth pin (internal teeth); 13. Crankshaft (rotating body); 13a. First eccentric portion (eccentric portion); 13b. Second eccentric portion (eccentric portion); 13c. Shaft body; 15. First swing gear (rotating body, swing gear); 16. Second swing gear (rotating body, swing gear); 18. Crankshaft bearing (other bearings); 19. Eccentric portion bearing (bearing); 21a, 21b, recess; 31. Inner ring; 32. Outer ring; 33. Rolling element; 34. Retainer; 35. Small diameter ring; 36. Large diameter ring; 37. Column; 38. Inner flange portion (convex portion); 39. Outer flange portion (convex portion). DETAILED DESCRIPTION

[0033] Next, embodiments of the present invention will be described with reference to the drawings.

[0034] <Reduction gear>

[0035] Figure 1 It is a cross-sectional view of the reduction gear 1 as a rotating device.

[0036] like Figure 1 As shown, the reduction gear 1 reduces the rotation of, for example, an electric motor (not shown) and outputs the reduced speed. The reduction gear 1 is a so-called eccentric oscillating type reduction gear. The reduction gear 1 comprises: a cylindrical housing 2; a gear carrier 3 rotatably disposed radially inward of the housing 2; and a reduction mechanism 4 coupled to the gear carrier 3. The central axis of the housing 2 coincides with the rotation axis of the gear carrier 3.

[0037] In the following description, these center axes and rotational axes are collectively referred to as the first rotational axis A1. The direction parallel to the first rotational axis A1 is referred to as the axial direction. The direction of rotation of the gear carrier 3 is referred to as the circumferential direction. The radial direction of the housing 2, which is orthogonal to the axial and circumferential directions, is referred to simply as the radial direction.

[0038] <Housing>

[0039] An outer flange portion 2a, projecting radially outward, is integrally formed on the outer circumferential surface of the housing 2. Multiple bolt holes 2b, for insertion of bolts (not shown), are formed in the outer flange portion 2a. The bolt holes 2b are arranged at equal intervals in the circumferential direction. Bolts (not shown) are inserted into the bolt holes 2b and tightened to, for example, the arm of an industrial robot, thereby securing the reduction gear 1.

[0040] The inner circumferential surface of the housing 2 is formed with a plurality of pin grooves 2c extending axially. The pin grooves 2c are arranged at equal intervals in the circumferential direction. An internally toothed pin 5 is inserted into each pin groove 2c. The internally toothed pin 5 functions as internal teeth that mesh with the swing gears 15 and 16 of the speed reduction mechanism 4, which will be described later.

[0041] Main bearings 6 are provided on both sides in the axial direction of the inner peripheral surface of the housing 2. The carrier 3 is rotatably supported by the housing 2 via the main bearings 6. The main bearings 6 are, for example, angular contact ball bearings.

[0042] <Gear rack>

[0043] The gear carrier 3 includes a disc-shaped base plate portion 7 and an end plate portion 8 that are disposed opposite to each other in the axial direction, and three column portions 9 that are formed to protrude from the base plate portion 7 toward the end plate portion 8 .

[0044] The pillars 9 are arranged at equal intervals in the circumferential direction. End plates 8 are arranged at the top ends 9a of the pillars 9. End plates 8 are fixed to the pillars 9 by bolts 10. In this state, a space having a constant width in the axial direction is formed between the base plate 7 and the end plates 8.

[0045] 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.

[0046] The outer peripheral surface of the base plate portion 7 and the outer peripheral surface of the end plate portion 8 are supported on the housing 2 in a rotatable manner by means of corresponding main bearings 6. Shaft insertion holes 7a and 8a are formed in the radial center of the base plate portion 7 and the radial center of the end plate portion 8, respectively. The two shaft insertion holes 7a and 8a are arranged on the same axis. In the base plate portion 7 and the end plate portion 8, three crankshaft insertion holes 7b and 8b are respectively formed between the circumferentially adjacent column portions 9. The crankshaft insertion holes 7b and 8b are respectively arranged on the same axis. That is, the center axis A2 of the crankshaft insertion holes 7b and 8b that are opposite in the axial direction is parallel to the first rotation axis A1. A crankshaft bearing 18 is provided in each crankshaft insertion hole 7b and 8b. The crankshaft bearing 18 is, for example, a tapered roller bearing.

[0047] <Reduction Mechanism>

[0048] The reduction mechanism 4 rotates the gear carrier 3 at a speed that is reduced by a certain ratio relative to the speed of the input shaft (not shown). The reduction mechanism 4 includes: three crankshafts 13, which are inserted into the crankshaft insertion holes 7b and 8b, respectively, and are rotatably supported by the gear carrier 3 (the base plate 7 and the end plate 8) via crankshaft bearings 18; a transmission spur gear 14, which is provided at the axial end of each crankshaft 13; and two oscillating gears 15 and 16 (a first oscillating gear 15 and a second oscillating gear 16), which are provided between the base plate 7 and the end plate 8 and oscillate and rotate in response to the rotation of the crankshafts 13.

[0049] The transmission spur gear 14 meshes with, for example, a motor shaft of an electric motor (not shown). Thus, the rotation of the electric motor (not shown) is transmitted to the transmission spur gear 14, causing the transmission spur gear 14 to rotate.

[0050] The crankshaft 13 includes a shaft body 13c that rotates about the central axis A2, and a first eccentric portion 13a and a second eccentric portion 13b formed at the axial center of the shaft body 13c. The shaft body 13c is rotatably supported on both sides of the axial direction by crankshaft bearings 18 on the gear carrier 3 (base plate 7 and end plate 8).

[0051] In the following description, both axial sides of the shaft body 13c are referred to as axial outer sides, and the axial center side of the shaft body 13c where the eccentric portions 13a and 13b are arranged is simply referred to as the axial center side.

[0052] The shaft body 13c and the transmission spur gear 14 are arranged on the same axis and are integrated. That is, the crankshaft 13 and the transmission spur gear 14 rotate integrally around the central axis A2. Hereinafter, the central axis A2 is referred to as the second rotation axis A2 of the crankshaft 13.

[0053] The first eccentric portion 13a and the second eccentric portion 13b are eccentric with respect to the second rotation axis A2. The first eccentric portion 13a and the second eccentric portion 13b are arranged axially adjacent to each other between the two crankshaft bearings 18. In other words, the first eccentric portion 13a and the second eccentric portion 13b are arranged axially adjacent to each other between the base plate portion 7 and the end plate portion 8. The first eccentric portion 13a and the second eccentric portion 13b are arranged in a manner that differs by a phase angle of 180°. Recesses 21a and 21b are formed on the axial outer side of each eccentric portion 13a, 13b over the entire circumference. The recesses 21a and 21b are used to limit the position of the eccentric portion bearing 19 described later.

[0054] Each eccentric portion 13a, 13b is provided with an eccentric portion bearing (an example of a bearing in the claims) 19. Details of the eccentric portion bearing 19 will be described later. The first oscillation gear 15 and the second oscillation gear 16 are rotatably supported on each crankshaft 13 via the eccentric portion bearing 19.

[0055] The first and second oscillating gears 15 and 16 are disposed in the space between the base plate 7 and the end plate 8. Through-holes 15a and 16a are formed in the first and second oscillating gears 15 and 16, respectively, for receiving eccentric bearings 19. Consequently, when the first and second eccentric portions 13a and 13b oscillate due to rotation of the crankshaft 13, the first and second oscillating gears 15 and 16 oscillate via the eccentric bearings 19.

[0056] Openings 15b and 16b are formed in the first and second swing gears 15 and 16, respectively, to prevent interference with the column portion 9. Shaft insertion holes 15c and 16c are formed in the radial centers of the first and second swing gears 15 and 16, respectively. External teeth 15d and 16d are formed on the outer circumferences of the first and second swing gears 15 and 16, respectively. The number of teeth on each of the external teeth 15d and 16d is, for example, one less than the number of internal tooth pins 5 of the housing 2.

[0057] <Eccentric bearing>

[0058] Figure 2 yes Figure 1 Enlarged view of Part II.

[0059] like Figure 1 、 Figure 2 As shown, the eccentric bearing 19 is a so-called needle roller bearing. It comprises an annular inner ring 31, integrally connected to the eccentric portions 13a and 13b of the crankshaft 13; an annular outer ring 32, integrally connected to the oscillating gears 15 and 16; a plurality of rolling elements 33 disposed between the inner and outer rings 31 and 32; and a retainer 34, which holds the rolling elements 33. The rolling elements 33 are needle rollers arranged parallel to the axial direction. The rolling elements 33 are arranged in a circumferential direction around the inner and outer rings 31 and 32.

[0060] Retainer

[0061] Figure 3 It is a perspective view of a cross section of the retainer 34 along the axial direction.

[0062] The holder 34 is formed of resin. As the resin, for example, nylon resin containing glass can be used. However, the present invention is not limited to this, and various resins can be used.

[0063] like Figure 2 、 Figure 3 As shown, the retainer 34 is integrally formed with: an annular small-diameter ring 35, which is arranged at an axially outer position than the rolling element 33; a large-diameter ring 36, which is arranged at an axially central position than the rolling element 33; and a plurality of columns 37, which connect the small-diameter ring 35 and the large-diameter ring 36.

[0064] The small-diameter ring 35 is formed to follow the outer circumferential surface of the inner ring 31. Specifically, the inner diameter D1 of the small-diameter ring 35 is slightly larger than the outer diameter D2 of the inner ring 31. An annular inner flange 38 is integrally formed at the axially outer end of the small-diameter ring 35, protruding axially outward from the inner ring 31. The inner flange 38 protrudes radially inward from the small-diameter ring 35. The inner diameter D3 of the inner flange 38 is smaller than the outer diameter D2 of the inner ring 31. Therefore, the inner flange 38 partially overlaps with the inner ring 31 when viewed axially.

[0065] A step portion 38 a is formed by the axial inner end surface of the inner flange portion 38 and the inner peripheral surface of the small-diameter ring 35 .

[0066] Each inner flange portion 38 is disposed in the corresponding recessed portion 21a, 21b of the eccentric portion 13a, 13b. The step portion 38a is disposed at a radially outer corner of the recessed portion 21a, 21b.

[0067] Each eccentric portion 13 a , 13 b is disposed between two crankshaft bearings 18 , and therefore the inner flange portion 38 is disposed between the crankshaft bearing 18 and the corresponding eccentric portion 13 a , 13 b .

[0068] The large-diameter ring 36 is formed to follow the inner circumference of the outer ring 32. Specifically, the outer diameter D4 of the large-diameter ring 36 is slightly smaller than the inner diameter D5 of the outer ring 32. An annular outer flange 39, projecting toward the axial center, is integrally formed at the axially center end of the large-diameter ring 36. In other words, the outer flange 39 is positioned between the two oscillation gears 15 and 16. As a result, the two outer flanges 39 are arranged side by side in the axial direction.

[0069] The outer flange portion 39 protrudes radially outward from the large-diameter ring 36. The outer diameter D6 of the outer flange portion 39 is larger than the inner diameter D5 of the outer ring 32. Therefore, the outer flange portion 39 partially overlaps with the outer ring 32 when viewed in the axial direction.

[0070] A step portion 39a is formed by the axially inner end surface of the outer flange portion 39 and the outer peripheral surface of the large-diameter ring 36. The corresponding corners of the oscillating gears 15 and 16 are arranged on the step portion 39a.

[0071] The column portions 37 extend in the axial direction and are arranged at equal intervals in the circumferential direction. The rolling elements 33 are respectively arranged in the pockets 41 defined by the column portions 37 , the small-diameter ring 35 , and the large-diameter ring 36 .

[0072] The column portion 37 is integrally formed with a plate-like portion 42 arranged on the radially inner side and an anti-slip portion 43 arranged on the radially outer side of the plate-like portion 42. The plate-like portion 42 is a plate-shaped member with the thickness direction as the circumferential direction. The plate-like portion 42 extends in the entire axial direction. The anti-slip portion 43 also extends in the entire axial direction. The anti-slip portion 43 is formed in such a manner that the circumferential thickness becomes thicker as it goes radially outward. In other words, the opening area of ​​the pocket 41 becomes smaller as it goes radially outward. The anti-slip portion 43 formed in this way can be used to prevent the rolling element 33 from falling out of the retainer 34 radially outward.

[0073] <Operation of the reduction gear>

[0074] Next, the operation of the reduction gear 1 will be described.

[0075] The transmission spur gear 14 and the crankshaft 13 are rotated integrally by an electric motor (not shown). Furthermore, the first and second oscillating gears 15 and 16 oscillate and rotate. As this oscillating rotation occurs, a portion of the external teeth 15d and 16d of each oscillating gear 15 and 16 meshes with the internal pin 5 of the housing 2. The number of teeth on each external tooth 15d and 16d is, for example, one less than the number of internal pins 5. Consequently, the meshing portion of each external tooth 15d and 16d is sequentially offset in the circumferential direction relative to the internal pin 5 (housing 2), causing each oscillating gear 15 and 16 to rotate. This rotation is reduced in speed relative to the rotation of the crankshaft 13.

[0076] As the swing gears 15 and 16 rotate, the crankshafts 13 also rotate around the first rotation axis A1 while rotating around the second rotation axis A2. Each crankshaft 13 is supported on the gear frame 3 (base plate portion 7, end plate portion 8) in a rotatable manner. Therefore, as the crankshafts 13 revolve, the gear frame 3 rotates. As a result, the reduction gear 1 reduces the rotation of the input shaft (not shown) and outputs it from the gear frame 3. Assuming that the gear frame 3 is fixed to the arm of an industrial robot, etc., the reduction gear 1 can reduce the rotation of the input shaft (not shown) and output it from the housing 2.

[0077] The retainer 34 of the eccentric bearing 19 has an inner flange 38. This inner flange 38 overlaps partially with the inner ring 31 (the corresponding eccentric portions 13a and 13b) when viewed axially. Therefore, if an axially adjacent retainer 34 attempts to move toward the axial center, the inner flange 38 contacts the inner ring 31 (the eccentric portions 13a and 13b). This restricts the retainer 45 from moving toward the axial center.

[0078] The retainer 34 of the eccentric bearing 19 has an outer flange 39. This flange 39 overlaps a portion of the outer ring 32 (the corresponding oscillation gears 15 and 16) when viewed axially. Therefore, if the retainer 34 attempts to move axially outward, the outer flange 39 contacts the outer ring 32 (the oscillation gears 15 and 16). This restricts the retainer 34 from moving axially outward.

[0079] The inner flange portion 38 is disposed between the crankshaft bearing 18 and the corresponding eccentric portions 13a, 13b. Therefore, if the retainer attempts to move axially outward, the inner flange portion 38 contacts the crankshaft bearing 18. In other words, the inner flange portion 38 also restricts the axial outward movement of the retainer 34.

[0080] The outer flange portion 39 is disposed between the two oscillation gears 15 and 16 and arranged side by side in the axial direction. Therefore, when the retainer 34 attempts to move toward the axial center, the two outer flange portions 39 contact each other. In other words, the outer flange portions 39 also restrict the movement of the retainer 34 toward the axial center.

[0081] As described above, the retainer 34 of the eccentric bearing 19 provided in the reduction gear 1 includes an inner flange 38 and an outer flange 39 that overlap with the inner ring 31 and outer ring 32 in the axial direction. Consequently, the inner flange 38 and outer flange 39 regulate the position of the retainer 34 relative to the inner ring 31 (eccentric portions 13a, 13b) and outer ring 32 (oscillation gears 15, 16). Consequently, the position of the rolling elements 33 can be controlled. This eliminates the need for spacers or other components other than the bearing to regulate the position of the rolling elements 33, simplifying the structure of the reduction gear 1.

[0082] To regulate the position of retainer 34, inner flanges 38 and outer flanges 39 are formed around the entire circumference of small-diameter ring 35 and large-diameter ring 36. This improves the rigidity of the areas regulating the position of retainer 34. This simplifies the structure of reduction gear 1 and more reliably regulates the position of retainer 34 (rolling elements 33).

[0083] The inner ring 31 of the eccentric bearing 19 is integrated with the eccentric portions 13a and 13b. In other words, portions of the eccentric portions 13a and 13b function as the inner ring 31. This configuration simplifies the structure of the eccentric bearing 19 itself, and allows the position of the retainer 34 (rolling elements 33) to be controlled with a simpler structure.

[0084] The inner flange portion 38 is disposed between the crankshaft bearing 18 and the corresponding eccentric portions 13a, 13b. Therefore, the inner flange portion 38 alone can restrict the movement of the retainer 34 (rolling elements 33) to both sides in the axial direction.

[0085] Recesses 21a and 21b are formed in each eccentric portion 13a and 13b. Corresponding inner flanges 38 are disposed in each recess 21a and 21b. Therefore, the position of the inner flanges 38 can be controlled without radially enlarging the eccentric portions 13a and 13b or complicating the structure surrounding the eccentric portions 13a and 13b.

[0086] The outer ring 32 of the eccentric bearing 19 is integrated with the oscillating gears 15 and 16. In other words, portions of the oscillating gears 15 and 16 function as the outer ring 32. This configuration simplifies the structure of the eccentric bearing 19 itself, and allows the position of the retainer 34 (rolling elements 33) to be controlled with a simpler structure.

[0087] The outer flange portion 39 is disposed between the two oscillation gears 15 and 16 and arranged side by side in the axial direction. Therefore, the outer flange portion 39 alone can restrict the movement of the cage 34 (rolling elements 33) to both sides in the axial direction.

[0088] The holder 34 is formed of resin, and therefore the holder 34 can be easily formed.

[0089] The present invention is not limited to the above-described embodiment, and includes embodiments in which various modifications are added to the above-described embodiment without departing from the spirit of the present invention.

[0090] For example, in the above embodiment, an eccentric oscillating speed reducer 1 is used as an example of a rotary device, and an eccentric bearing 19 is provided in the speed reducer 1. However, the present invention is not limited to this embodiment, and the eccentric bearing 19 can be used in various rotary devices using bearings. Alternatively, the inner ring 31 may not be integrally formed with the eccentric portions 13a and 13b, or the outer ring 32 may not be integrally formed with the oscillating gears 15 and 16. Alternatively, the eccentric bearing 19 can be used as a single bearing.

[0091] In the above embodiment, the eccentric bearing 19 is described as a so-called needle roller bearing. However, the present invention is not limited to this, and the structure of the eccentric bearing 19 can be adopted in various bearings having rolling elements. For example, the structure of the retainer 34 can also be adopted in a deep groove ball bearing.

[0092] In the above embodiment, the case where the retainer 34 includes both the inner flange portion 38 and the outer flange portion 39 has been described. However, this is not limited to this. Figure 4 As shown in the first modified example of the retainer 34, the retainer 34 may also include only the inner flange portion 38. Figure 5 As in the second modified example of the retainer 34 shown, the retainer 34 may include only the outer flange portion 39 . Figure 4 、 Figure 5Respectively with the aforementioned Figure 3 In the case of such a configuration, the position of the cage 34 (rolling elements 33) can also be restricted.

[0093] In the above embodiment, retainer 34 is described as comprising a small-diameter ring 35, a large-diameter ring 36, an inner flange portion 38, and an outer flange portion 39. However, this is not limiting. Retainer 34 may simply have a protrusion that projects axially outward from the axial end of at least one of the inner ring 31 and the outer ring 32. This protrusion only needs to overlap at least one of the inner ring 31 and the outer ring 32 when viewed axially. The protrusion does not need to be formed along the entire circumference. Even with this configuration, the position of retainer 34 (rolling elements 33) can be controlled.

[0094] In the above embodiment, the reduction gear 1 is described as an eccentric oscillating reduction gear having multiple (e.g., three) crankshafts 13. However, the present invention is not limited to this, and in such a reduction gear, a single crankshaft 13 may be provided. In this case, the crankshaft 13 is arranged coaxially with the first rotation axis A1.

[0095] In the above embodiment, the reduction gear 1 is described as having two oscillating gears 15 and 16. However, this is not limiting; at least one oscillating gear is sufficient. Three or more oscillating gears may also be provided. The number of eccentric portions can be adjusted to match the number of oscillating gears. Even with this configuration, the reduction gear 1 can function as an eccentric oscillating type reduction gear.

[0096] In the embodiments disclosed in this specification, components composed of multiple objects may be integrated, and conversely, components composed of a single object may be divided into multiple objects. Regardless of whether they are integrated or not, they may be configured in a manner that achieves the purpose of the invention.

Claims

1. A rotating device, wherein: The rotating device has: bearings; and a rotating body in which the bearing is fitted, The bearing has: inner circle; an outer ring disposed radially outward of the inner ring; a plurality of rolling elements disposed between the inner ring and the outer ring; and a retainer that retains the plurality of rolling elements, The retainer includes a protrusion formed to protrude axially outward from an axial end portion of at least one of the inner ring and the outer ring. The convex portion overlaps with at least one of the inner ring and the outer ring when viewed in the axial direction.

2. The rotating device according to claim 1, wherein: The retainer comprises: a circular, small-diameter ring; an annular large-diameter ring disposed radially outward of the small-diameter ring; and a column portion extending in the radial direction so as to connect the small-diameter ring and the large-diameter ring, The convex portion includes an inner flange portion protruding from the inner side of the small-diameter ring in the radial direction, The inner diameter of the inner flange portion is smaller than the outer diameter of the inner ring.

3. The rotating device according to claim 1 or 2, wherein: The retainer comprises: a circular, small-diameter ring; an annular large-diameter ring disposed radially outward of the small-diameter ring; a column portion extending in the radial direction so as to connect the small-diameter ring and the large-diameter ring, The convex portion includes an outer flange portion protruding radially outward from the large-diameter ring. The outer diameter of the outer flange portion is larger than the inner diameter of the outer ring.

4. The rotating device according to claim 1, wherein The rotating device comprises: a housing having an internally toothed gear; a gear rack rotatably supported on the housing; a shaft body and at least one crankshaft, the shaft body being rotatably supported on the gear carrier via other bearings, the at least one crankshaft being provided on the shaft body; and a swing gear meshing with the internal gear, The crankshaft has an eccentric portion that is eccentric with respect to the rotation axis of the shaft body. The swing gear is rotatably supported by the eccentric portion via the bearing. The inner ring is integrated with the eccentric portion, The protrusion overlaps with the inner ring when viewed in the axial direction.

5. The rotating device according to claim 4, wherein: The convex portion is arranged between the other bearing and the eccentric portion.

6. The rotating device according to claim 5, wherein: The rotating device has a recessed portion formed on the outer peripheral surface of the crankshaft. The convex portion is arranged in the concave portion.

7. The rotating device according to claim 1, wherein: The rotating device comprises: a housing having an internally toothed gear; a gear rack rotatably supported on the housing; a shaft body and at least one crankshaft, the shaft body being rotatably supported on the gear carrier via other bearings, the at least one crankshaft being provided on the shaft body; and a swing gear meshing with the internal gear, The crankshaft has an eccentric portion that is eccentric with respect to the rotation axis of the shaft body. The swing gear is rotatably supported by the eccentric portion via the bearing. The outer ring is integrated with the swing gear. The protrusion overlaps with the outer ring when viewed in the axial direction.

8. The rotating device according to claim 4 or 7, wherein: The rotating device includes a plurality of the swing gears. The convex portion is arranged between the oscillation gears adjacent to each other in the axial direction.

9. The rotating device according to claim 1, wherein: The holder is formed of resin.

10. A rotating device, wherein: The rotating device has: a housing having an internally toothed gear; a gear rack rotatably supported on the housing; a shaft body and at least one crankshaft, wherein the shaft body is rotatably supported by the gear carrier, and the at least one crankshaft is provided on the shaft body; and a swing gear meshing with the internal gear, The crankshaft has an eccentric portion that is eccentric with respect to the rotation axis of the shaft body. The swing gear is rotatably supported on the eccentric portion by a bearing. The bearing has: inner circle; an outer ring disposed radially outward of the inner ring; a plurality of rolling elements disposed between the inner ring and the outer ring; and a retainer that retains the plurality of rolling elements, The retainer comprises: a circular, small-diameter ring; an annular large-diameter ring disposed radially outward of the small-diameter ring; a column portion extending in the radial direction so as to connect the small-diameter ring and the large-diameter ring; and a convex portion formed to protrude axially outward from an axial end portion of at least one of the inner ring and the outer ring from at least one of the small-diameter ring and the large-diameter ring; The convex portion overlaps with at least one of the inner ring and the outer ring when viewed in the axial direction.

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