Rotary device

Abstract

To provide a rotary device capable of regulating a position of a rolling element with a simple structure.SOLUTION: A speed reduction device 1 comprises an eccentric bearing 19, and a crankshaft 13 and oscillating external gears 15, 16 into which the eccentric bearing 19 is fitted. The eccentric bearing 19 comprises an inner ring 31, an outer ring 32 that is arranged radially outward of the inner ring 31, a plurality of rolling elements 33 that are arranged between the inner ring 31 and the outer ring 32, and a holder 34 that holds the plurality of rolling elements 33. The holder 34 has an inward flange part 38 and an outward flange part 39 that protrude axially outward beyond axial end parts of at least one of the inner ring 31 and the outer ring 32. The inward flange part 38 and the outward flange part 39 overlap with the inner ring 31 and the outer ring 32 when viewed from an axial direction .SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] Among rotating devices, there is a reduction gear that receives rotation from, for example, an electric motor and outputs the rotation by slowing or accelerating it. Among reduction gears, there is, for example, an eccentric oscillating reduction gear that has high rotational position accuracy and load resistance. This type of reduction gear includes, for example, a case with an internal gear formed on its inner circumferential surface, an oscillating external gear (planetary gear) that meshes with the internal gear and rotates in an oscillating manner, a crankshaft (eccentric shaft) that has an eccentric part that rotatably supports the oscillating external gear and transmits rotational force to the oscillating external gear, and a carrier (carrier flange, output flange) that rotatably supports the crankshaft and transmits the rotational force of the oscillating external gear.

[0003] The crankshaft is provided with main bearings (first bearing, second bearing) axially outward of the eccentric portion for rotatably supporting the carrier. The eccentric portion is provided with an eccentric portion bearing (eccentric body bearing) for rotatably supporting the oscillating external gear. These bearings include an inner ring, an outer ring disposed radially outward of the inner ring, multiple rolling elements disposed between the inner ring and the outer ring, and a cage that holds the rolling elements. Some eccentric portion bearings have the inner ring and eccentric portion molded as a single unit to simplify the structure (see, for example, Patent Document 1). This type of bearing includes a spacer provided between the main bearing and the eccentric bearing. The spacer functions as a retainer for the eccentric bearing, thereby restricting the position of the rolling elements held by the retainer. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2023-55060 Summary of the Invention [Problem to be solved by the invention]

[0005] When spacers are used to regulate the positions of the rolling elements as in the above-mentioned prior art, there is a problem that the number of parts increases and the structure becomes complicated.

[0006] The present invention provides a rotating device that can regulate the position of a rolling element with a simple structure. [Means for solving the problem]

[0007] A rotating device according to one aspect of the present invention comprises a bearing and a rotating body into which the bearing is fitted, the bearing comprising 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 a retainer that holds the plurality of rolling elements, the retainer having a convex portion formed to protrude axially outward beyond the axial ends of at least one of the inner ring and the outer ring, the convex portion overlapping with at least one of the inner ring and the outer ring when viewed in the axial direction.

[0008] With this configuration, the position of the cage relative to the inner ring and outer ring can be regulated by the protrusions, which in turn regulates the position of the rolling elements. Since there is no need to provide components other than the bearing, such as spacers, to regulate the position of the rolling elements, the structure of the rotating device can be simplified.

[0009] In the above configuration, the retainer comprises an annular small diameter ring, an annular large diameter ring arranged radially outside the small diameter ring, and a column portion extending radially to connect the small diameter ring and the large diameter ring, and the convex portion includes an inner flange portion that protrudes radially inward from the small diameter ring, and the inner diameter of the inner flange portion may be smaller than the outer diameter of the inner ring.

[0010] In the above configuration, the retainer comprises an annular small diameter ring, an annular large diameter ring arranged radially outside the small diameter ring, and a column portion extending radially to connect the small diameter ring and the large diameter ring, and the convex portion includes an outer flange portion that protrudes radially outward from the large diameter ring, and the outer diameter of the outer flange portion may be larger than the inner diameter of the outer ring.

[0011] In the above configuration, the device comprises a case having an internal gear, a carrier rotatably supported by the case, a shaft body rotatably supported by the carrier via another 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 the bearing and meshing with the internal gear, wherein the inner ring is integrated with the eccentric portion, and the convex portion may overlap the inner ring when viewed in the axial direction.

[0012] In the aforementioned configuration, the protrusion may be disposed between the other bearing and the eccentric portion.

[0013] In the above configuration, the crankshaft may have a recess formed on its outer peripheral surface, and the protrusion may be disposed in the recess.

[0014] In the above configuration, the device comprises a case having an internal gear, a carrier rotatably supported on the case, a shaft body rotatably supported on the carrier via another bearing, 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 on the eccentric portion via the bearing and meshing with the internal gear, wherein the outer ring is integrated with the oscillating external gear, and the convex portion overlaps with the outer ring when viewed from the axial direction.

[0015] In the above configuration, a plurality of the oscillating external gears may be provided, and the protrusions may be disposed between the oscillating external gears adjacent to each other in the axial direction.

[0016] In the above configuration, the cage may be made of resin.

[0017] 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, and at least one crankshaft having an eccentric portion provided on the shaft body and eccentric with respect to the rotation axis of the shaft body, and an oscillating external gear rotatably supported via a bearing on the eccentric portion and meshing with the internal gear, the bearing including an inner ring, an outer ring disposed radially outward of the inner ring, and a plurality of bearings disposed between the inner ring and the outer ring. and a retainer that holds the plurality of rolling elements, wherein the retainer comprises an annular small-diameter ring, an annular large-diameter ring arranged radially outside the small-diameter ring, pillar portions extending radially to connect the small-diameter ring and the large-diameter ring, and protrusions formed on at least one of the small-diameter ring and the large-diameter ring so as to protrude axially outward beyond the axial ends of at least one of the inner ring and the outer ring, and the protrusions overlap with at least one of the inner ring and the outer ring when viewed in the axial direction.

[0018] By configuring in this way, the position of the rolling element can be regulated with a simple structure in an eccentric oscillating type reducer. [Effects of the Invention]

[0019] The above-described rotating device can regulate the position of the rolling elements with a simple structure. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a cross-sectional view of a reduction gear transmission according to an embodiment of the present invention. [Figure 2] FIG. 2 is an enlarged view of part II in FIG. [Figure 3] 1 is a perspective view of a cross section along an axial direction of a cage according to an embodiment of the present invention. [Figure 4]FIG. 10 is a perspective view of a cross section along the axial direction of a cage in a first modified example of the embodiment of the present invention. [Figure 5] FIG. 10 is a perspective view of a cross section along the axial direction of a cage in a second modified example of the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0021] Next, an embodiment of the present invention will be described with reference to the drawings.

[0022] <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.

[0023] <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.

[0024] 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.

[0025] <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.

[0026] 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.

[0027] <Deceleration mechanism> The reduction gear mechanism 4 rotates the carrier 3 at a rotation speed that is reduced by a fixed ratio relative to the rotation speed of the input shaft 101. The reduction gear mechanism 4 includes three crankshafts 13 that are inserted into the crank insertion holes 7b, 8b and rotatably supported on the carrier 3 (base plate portion 7 and end plate portion 8) via crank bearings 18, 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) that are provided between the base plate portion 7 and the end plate portion 8 and that oscillate and rotate in conjunction with the rotation of the crankshafts 13.

[0028] The transmission spur gear 14 is meshed with, for example, the motor shaft of an electric motor (not shown), so that the rotation of the electric motor (not shown) is transmitted to the transmission spur gear 14, causing the transmission spur gear 14 to rotate.

[0029] The crankshaft 13 has a shaft body 13c that rotates around a 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 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.

[0030] 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.

[0031] 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 difference of 180°. Recesses 21a and 21b are formed around the entire periphery on the outer side of each eccentric portion 13a and 13b in the axial direction. The recesses 21a and 21b are used to regulate the position of an eccentric portion bearing 19, which will be described later.

[0032] Each of the eccentric portions 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 oscillating external gear 15 and the second oscillating external gear 16 are rotatably supported on each crankshaft 13 via the eccentric portion bearing 19.

[0033] 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 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.

[0034] 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.

[0035] <Eccentric bearing> FIG. 2 is an enlarged view of part II in FIG. As shown in Figures 1 and 2, 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.

[0036] <Cage> FIG. 3 is a perspective view of a cross section of the cage 34 taken along the axial direction. 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. As shown in Figures 2 and 3, 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.

[0037] The small diameter ring 35 is formed to fit along the outer peripheral surface of the inner ring 31. In other words, 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 portion 38 that protrudes axially outward beyond the inner ring 31 is integrally formed at the outer axial end of the small diameter ring 35. The inner flange portion 38 protrudes radially inward from the small diameter ring 35. The inner diameter D3 of the inner flange portion 38 is smaller than the outer diameter D2 of the inner ring 31. Therefore, the inner flange portion 38 overlaps a portion of the inner ring 31 when viewed axially.

[0038] The axially inner end face of the inner flange portion 38 and the inner peripheral surface of the small diameter ring 35 form a step portion 38a. Each inner flange portion 38 is disposed in the recessed portion 21a, 21b of the corresponding eccentric portion 13a, 13b. A step portion 38a is disposed at the radially outer corner of each of the recessed portions 21a, 21b. Since each eccentric portion 13a, 13b is disposed between two crank bearings 18, the inner flange portion 38 is disposed between the crank bearing 18 and the corresponding eccentric portion 13a, 13b.

[0039] 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 D4 of the large diameter ring 36 is slightly smaller than the inner diameter D5 of the outer ring 32. An annular outer flange portion 39 that protrudes toward the center in the axial direction is integrally formed at the end of the large diameter ring 36 toward the center in the axial direction. In other words, the outer flange portion 39 is disposed between the two oscillating external gears 15, 16. As a result, the two outer flange portions 39 are disposed side by side in the axial direction.

[0040] 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 overlaps with a portion of the outer ring 32 when viewed in the axial direction. A step portion 39a is formed by the axially inner end face of the outer flange portion 39 and the outer peripheral surface of the large diameter ring 36. Corners of the corresponding oscillating external gears 15, 16 are arranged in the step portion 39a.

[0041] The pillars 37 extend along the axial direction and are arranged at equal intervals in the circumferential direction. The pillars 37, the small diameter ring 35, and the large diameter ring 36 define pockets 41, in which the rolling elements 33 are arranged.

[0042] The column portion 37 is integrally formed with a plate-shaped portion 42 disposed radially inward and a drop-out prevention portion 43 disposed radially outward of the plate-shaped portion 42. The plate-shaped portion 42 is a plate-shaped member whose thickness direction is the circumferential direction. The plate-shaped portion 42 extends over the entire axial direction. The drop-out prevention portion 43 also extends over the entire axial direction. The drop-out prevention portion 43 is formed so that its circumferential thickness gradually increases toward the radially outward direction. In other words, the opening area of ​​the pocket 41 decreases toward the radially outward direction. The drop-out prevention portion 43 formed in this manner can prevent the rolling elements 33 from dropping out radially outward from the cage 34.

[0043] <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.

[0044] As each of the oscillating external gears 15, 16 rotates, each of the crankshafts 13 also revolves around the first rotation axis A1 while rotating about the second rotation axis 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 the input shaft 101 and outputs it from the carrier 3. If the carrier 3 is fixed to the arm of an industrial robot or the like, the reduction gear 1 can reduce the rotation of the input shaft 101 and output it from the case 2.

[0045] Here, the cage 34 of the eccentric portion bearing 19 has an inner flange portion 38. The inner flange portion 38 overlaps a part of the inner ring 31 (the corresponding eccentric portion 13a, 13b) when viewed in the axial direction. Therefore, when adjacent cages 34 in the axial direction attempt to move toward the center in the axial direction, the inner flange portion 38 comes into contact with the inner ring 31 (the eccentric portion 13a, 13b). This restricts the movement of the cage 45 toward the center in the axial direction.

[0046] The cage 34 of the eccentric portion bearing 19 has an outer flange portion 39. The outer flange portion 39 overlaps a part of the outer ring 32 (the corresponding oscillating external gears 15, 16) when viewed in the axial direction. Therefore, when the cage 34 attempts to move outward in the axial direction, the outer flange portion 39 comes into contact with the outer ring 32 (the oscillating external gears 15, 16). This restricts the cage 45 from moving outward in the axial direction.

[0047] Since the inner flange portion 38 is disposed between the crank bearing 18 and the corresponding eccentric portion 13a, 13b, when the cage attempts to move outward in the axial direction, the inner flange portion 38 comes into contact with the crank bearing 18. In other words, the outward movement of the cage 34 in the axial direction is also restricted by the inner flange portion 38.

[0048] The outer flange portions 39 are disposed between the two oscillating external gears 15, 16 and are disposed side by side in the axial direction, so that when the cage attempts to move toward the center in the axial direction, the two outer flange portions 39 come into contact with each other. In other words, the movement of the cage 34 toward the center in the axial direction is also restricted by the outer flange portions 39.

[0049] As described above, the cage 34 of the eccentric portion bearing 19 provided in the reduction gear device 1 described above has an inner flange portion 38 and an outer flange portion 39 that overlap with the inner ring 31 and the outer ring 32 when viewed in the axial direction. Therefore, the position of the cage 34 relative to the inner ring 31 (eccentric portions 13a, 13b) and the outer ring 32 (oscillating external gears 15, 16) can be regulated by the inner flange portion 38 and the outer flange portion 39. As a result, the position of the rolling elements 33 can be regulated. Since there is no need to prepare parts other than bearings, such as spacers, to regulate the position of the rolling elements 33, the structure of the reduction gear device 1 can be simplified.

[0050] In order to regulate the position of the retainer 34, an inner flange portion 38 and an outer flange portion 39 are formed around the entire circumference of the inner ring 31 and the outer ring 32. This increases the rigidity of the portion that regulates the position of the retainer 34. This simplifies the structure of the reduction gear device 1 while more reliably regulating the position of the retainer 34 (rolling elements 33).

[0051] In the eccentric portion bearing 19, the inner ring 31 is integrated with the eccentric portions 13a and 13b. In other words, a part of the eccentric portions 13a and 13b serves as the inner ring 31. With this configuration, the structure of the eccentric portion bearing 19 itself can be simplified, and the position of the cage 34 (rolling elements 33) can be regulated with an even simpler structure.

[0052] The inner flange portion 38 is disposed between the crank bearing 18 and the corresponding eccentric portion 13a, 13b. Therefore, the inner flange portion 38 alone can restrict the movement of the cage 34 (rolling elements 33) to both sides in the axial direction. Recesses 21a and 21b are formed in the eccentric portions 13a and 13b, respectively. Corresponding inner flange portions 38 are disposed in the recesses 21a and 21b. This allows the positions of the inner flange portions 38 to be regulated without increasing the radial size of the eccentric portions 13a and 13b and without complicating the structure around the eccentric portions 13a and 13b.

[0053] In the eccentric portion bearing 19, the outer ring 32 is integrated with the oscillating external gears 15, 16. In other words, a part of the oscillating external gears 15, 16 serves as the outer ring 32. By configuring it in this way, the structure of the eccentric portion bearing 19 itself can be simplified, and the position of the retainer 34 (rolling elements 33) can be regulated with an even simpler structure. The outer flange portion 39 is disposed between the two oscillating external gears 15, 16 and is disposed side by side in the axial direction. Therefore, the outer flange portion 39 alone can restrict movement of the cage 34 (rolling elements 33) to both sides in the axial direction.

[0054] Since the cage 34 is made of resin, the cage 34 can be easily formed.

[0055] The present invention is not limited to the above-described embodiment, and includes various modifications to the above-described embodiment without departing from the spirit of the present invention.

[0056] 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.

[0057] 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.

[0058] In the above-described embodiment, the cage 34 has been described as having both an inner flange portion 38 and an outer flange portion 39. However, this is not limited to this, and the cage 34 may have only the inner flange portion 38, as in a first modified example of the cage 34 shown in FIG. 4. The cage 34 may have only the outer flange portion 39, as in a second modified example of the cage 34 shown in FIG. 5. FIGS. 4 and 5 each correspond to the above-described FIG. 3. Even in this configuration, the position of the cage 34 (rolling elements 33) can be regulated.

[0059] In the above embodiment, the cage 34 has been described as including the small diameter ring 35, the large diameter ring 36, the inner flange portion 38, and the outer flange portion 39. However, this is not limited thereto, and the cage 34 may have a convex portion formed to protrude axially outward beyond the axial end of at least one of the inner ring 31 and the outer ring 32. This convex portion may overlap with at least one of the inner ring 31 and the outer ring 32 when viewed from the axial direction. The convex portion does not have to be formed around the entire circumference. Even with this configuration, the position of the cage 34 (rolling elements 33) can be regulated.

[0060] 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.

[0061] 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.

[0062] 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]

[0063] 1...Reduction gear (rotating gear) 2. Case 3. Career 5...Inner tooth pin (inner tooth) 13...Crankshaft (rotating body) 13a...First eccentric part (eccentric part) 13b...Second eccentric part (eccentric part) 13c...shaft body 15...First oscillating external gear (rotating body, oscillating external gear) 16... Second oscillating external gear (rotating body, oscillating external gear) 18...Crank bearing (other bearings) 19...Eccentric bearing (bearing) 21a, 21b...recessed portion 31...Inner circle 32...Outer ring 33...Rolling element 34...Cage 35...Small diameter ring 36...Large diameter ring 37...Column part 38...Inner flange (convex part) 39...Outer flange (convex part)

Claims

1. A bearing, a rotating body into which the bearing is fitted; Equipped with The bearing is With 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; a cage that holds the plurality of rolling elements; Equipped with the cage has a protrusion formed to protrude axially outward beyond an axial end of at least one of the inner ring and the outer ring, the protrusion overlaps with at least one of the inner ring and the outer ring when viewed from the axial direction; Rotating device.

2. The retainer is an annular small diameter ring; a large diameter ring disposed radially outward of the small diameter ring; a column portion extending radially so as to connect the small diameter ring and the large diameter ring; Equipped with the protruding portion includes an inner flange portion that protrudes radially inward from the small diameter ring, The inner diameter of the inner flange portion is smaller than the outer diameter of the inner ring. The rotating device according to claim 1 .

3. The retainer is an annular small diameter ring; a large diameter ring disposed radially outward of the small diameter ring; a column portion extending radially so as to connect the small diameter ring and the large diameter ring; Equipped with the protruding portion includes an outer flange portion that protrudes 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. The rotating device according to claim 1 or 2.

4. a case having an internal gear; a carrier rotatably supported by the case; a shaft body rotatably supported on the carrier via another 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 the bearing and that meshes with the internal gear; Equipped with the inner ring is integrated with the eccentric portion, the protrusion overlaps the inner ring when viewed from the axial direction, The rotating device according to claim 1 .

5. the protrusion is disposed between the other bearing and the eccentric portion. The rotating device according to claim 4.

6. a recess formed on the outer peripheral surface of the crankshaft, The protrusion is disposed in the recess. The rotating device according to claim 5 .

7. a case having an internal gear; a carrier rotatably supported by the case; a shaft body rotatably supported on the carrier via another 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 the bearing and that meshes with the internal gear; Equipped with the outer ring is integrated with the oscillating external gear, the protrusion overlaps the outer ring when viewed in the axial direction, The rotating device according to claim 1 .

8. A plurality of the oscillating external gears is provided, the protrusions are arranged between the oscillating external gears adjacent to each other in the axial direction, The rotating device according to claim 4 or claim 7.

9. The cage is formed of resin. The rotating device according to claim 1 .

10. a case having an internal gear; a carrier rotatably supported by the case; at least one crankshaft having a shaft body rotatably supported by the carrier and an eccentric portion provided on the shaft body and eccentric with respect to a rotation axis of the shaft body; an oscillating external gear that is rotatably supported on the eccentric portion via a bearing and that meshes with the internal gear; Equipped with The bearing is With 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; a cage that holds the plurality of rolling elements; Equipped with The retainer is an annular small diameter ring; a large diameter ring disposed radially outward of the small diameter ring; a column portion extending radially so as to connect the small diameter ring and the large diameter ring; a convex portion formed on at least one of the small diameter ring and the large diameter ring and protruding axially outward beyond an axial end portion of at least one of the inner ring and the outer ring; Equipped with the protrusion overlaps with at least one of the inner ring and the outer ring when viewed from the axial direction; Rotating device.

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