JP2019052726A - Planetary gear device - Google Patents

Abstract

To provide a planetary gear device capable of making loads that multiple planetary gears receive when meshing with the other gear, equal while attaining a reduction in backlash.SOLUTION: A planetary gear device 1 comprises: an internal gear 30 which is an inner gear; a sun gear 20 which is an outer gear disposed coaxially with the internal gear 30; multiple planetary gears 50 which are outer gears revolved around the sun gear 20 while being meshed to the internal gear 30 and the sun gear 20; an output gear 40 which is an inner gear or an outer gear for which the number of teeth is different from the internal gear 30 and the sun gear 20, meshed to the multiple planetary gears 50 and disposed coaxially with the internal gear 30 and the sun gear 20 and in a relatively rotatable manner with respect to the internal gear 30 and the sun gear 20; multiple support members 60 which support each of the multiple planetary gears 50 in a rotatable manner; and an energizing member 100 which couples the multiple support members 60 with each other and energizes each of the multiple planetary gears 50 in a radial direction.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a planetary gear device.

  Patent Document 1 discloses a technique for removing and reducing backlash between gears by urging a planetary gear in the radial direction and pressing it against another gear.

JP 2010-151269 A

  In the technique described in Patent Document 1 described above, a biasing portion that biases a plurality of planetary gears in the radial direction is provided for each planetary gear. In this case, it is difficult to set the urging force of the urging unit so that the force pressing each planetary gear against the other gear is equal. If there is a difference in the urging force applied to each planetary gear, the load applied to one planetary gear becomes larger than that of the other planetary gear, and a problem such that only one planetary gear wears out easily is likely to occur.

  An object of the present invention is to provide a planetary gear device that can equalize the load received when a plurality of planetary gears mesh with other gears while reducing backlash.

  The planetary gear device of the present invention includes an internal gear as an internal gear, a sun gear as an external gear arranged coaxially with the internal gear, and the sun gear while meshing with the internal gear and the sun gear. A plurality of planetary gears that are external gears revolving around the inner gear, and the internal gear and the sun gear are internal gears or external gears having different numbers of teeth, meshing with the plurality of planetary gears, and An output gear arranged coaxially with the gear and the sun gear and relatively rotatable with respect to the internal gear and the sun gear, and a plurality of support members for rotatably supporting each of the plurality of planetary gears And a biasing member that couples the plurality of support members and biases each of the plurality of support members in the radial direction.

  According to the planetary gear device of the present invention, each of the plurality of planetary gears is urged in the radial direction by the urging member. Thereby, the planetary gear apparatus can maintain the state pressed against the other gear with which each planetary gear meshes. Therefore, the planetary gear device can reduce backlash that occurs between the planetary gear and another gear. In the planetary gear device, since a plurality of support members are connected by an urging member, if there is a dimensional error in the planetary gear or another gear meshing with the planetary gear, only one planetary gear is used. Even if a large load is applied, the load received by one planetary gear can be distributed to other planetary gears. As a result, the planetary gear device can equalize the load received when each planetary gear meshes with another gear.

It is an axial sectional view of the planetary gear device in the first embodiment of the present invention, and shows a cross section taken along line II of FIG. It is sectional drawing of the planetary gear apparatus in the II-II line | wire of FIG. It is an axial direction sectional view of the planetary gear device in the second embodiment, and shows a section taken along line III-III in FIG. It is sectional drawing of the planetary gear apparatus in the IV-IV line | wire of FIG.

<1. First embodiment>
(1-1: Schematic configuration of planetary gear device 1)
Hereinafter, an embodiment to which a planetary gear device according to the present invention is applied will be described with reference to the drawings. First, with reference to FIG.1 and FIG.2, the structure of the planetary gear apparatus 1 in 1st embodiment of this invention is demonstrated.

  As shown in FIGS. 1 and 2, the planetary gear device 1 includes a housing 10, a sun gear 20, an internal gear 30, an output gear 40, three planetary gears 50, and three support members 60. Is mainly provided. The housing 10 has a cylindrical shape formed by connecting three housing members (referred to as a first housing member 11, a second housing member 12, and a third housing member 13 in order from the left side shown in FIG. 1) with bolts. It is a member. In addition, illustration of the housing 10 is abbreviate | omitted in FIG.

  The sun gear 20 is an external gear integrally formed with the input shaft member 2 having the input / output axis A as the rotation center. The internal gear 30 is an internal gear arranged coaxially with the sun gear 20 and is fixed to the housing 10. Specifically, the internal gear 30 is fixed to the first housing member 11 and the first lid portion 31 formed in an annular shape with bolts. The output gear 40 is an internal gear having a different number of teeth from the sun gear 20 and the internal gear 30, is coaxial with the sun gear 20 and the internal gear 30, and is relative to the sun gear 20 and the internal gear 30. Arranged to be rotatable. The output gear 40 is fixed to the second lid portion 41 formed in an annular shape with a bolt.

  The planetary gear 50 is an external gear that meshes with the sun gear 20, the internal gear 30, and the output gear 40. Each of the plurality of support members 60 includes a planetary shaft member 61 inserted into the planetary gear 50 and a pair of collars 62 fixed to the planetary shaft member 61 on both sides in the axial direction across the planetary gear 50. A plurality of first needle bearings 71 are rotatably arranged between the outer peripheral surface of the planetary shaft member 61 and the inner peripheral surface of the planetary gear 50, and each support member 60 can rotate the planetary gear 50. To support.

  A first deep groove ball bearing 81 and a second deep groove ball bearing 82 are provided on both sides in the axial direction of the input shaft member 2 across the sun gear 20. The first deep groove ball bearing 81 is provided between the outer peripheral surface of the input shaft member 2 and the inner peripheral surface of the first lid portion 31, and the sun gear 20 is first through the first deep groove ball bearing 81. The lid 31 is rotatably supported.

  The inner ring 81a of the first deep groove ball bearing 81 is externally fitted to the input shaft member 2 on one side (left side in FIG. 1) of the input / output axis A with respect to the sun gear 20, and is close to the sun gear 20 ( The movement to the right side in FIG. On the other hand, the outer ring 81b of the first deep groove ball bearing 81 has a surface that faces one side in the axial direction of the outer ring 81b locked to the first lid portion 31, and moves to the side away from the sun gear 20 (left side in FIG. 1). It is regulated by the first lid part 31. Thus, in the relationship between the sun gear 20, the housing 10, and the internal gear 30, the sun gear 20 is axial with respect to the housing 10 and the internal gear 30 via the first deep groove ball bearing 81 and the first lid portion 31. Displacement to one side (left side in FIG. 1) is restricted.

  The second deep groove ball bearing 82 is provided between the outer peripheral surface of the input shaft member 2 and the inner peripheral surface of the second lid portion 41, and the sun gear 20 is second through the second deep groove ball bearing 82. The lid 41 is rotatably supported. The inner ring 82a of the second deep groove ball bearing 82 is externally fitted to the input shaft member 2 on the other side in the axial direction of the input / output axis A (right side in FIG. 1) than the sun gear 20, and is close to the sun gear 20 ( Movement to the left in FIG. 1 is regulated by the sun gear 20. On the other hand, the outer ring 82b of the second deep groove ball bearing 82 has a surface facing the other side in the axial direction of the outer ring 82b engaged with the second lid portion 41, and the outer ring 82b moves to the side away from the sun gear 20 (right side in FIG. 1). It is regulated by the second lid part 41. Thus, in the relationship between the sun gear 20 and the output gear 40, the sun gear 20 moves to the other side in the axial direction with respect to the output gear 40 (the right side in FIG. 1) via the second deep groove ball bearing 82 and the second lid portion 41. Displacement is regulated.

  A third deep groove ball bearing 83 is provided between the outer peripheral surface of the output gear 40 and the inner peripheral surface of the third housing member 13, and the output gear 40 is provided with respect to the housing 10 with respect to the third deep groove ball bearing 83. It is supported rotatably through the.

  Here, the portion of the output gear 40 where the internal teeth 40a are formed has a larger radial thickness dimension (the vertical dimension in FIG. 1) than the portion where the internal teeth 40a are not formed. Further, the outer diameter of the portion where the inner teeth 40 a are formed is larger than the outer diameter of the portion where the inner teeth 40 a are not formed, and a stepped portion 40 b is formed on the outer peripheral surface of the output gear 40. And the step part 40b latches the surface which faces the axial direction one side of the inner ring | wheel 83a of the 3rd deep groove ball bearing 83. FIG. Further, the outer diameter of the second lid portion 41 is larger than the outer diameter of the portion where the inner teeth 40 a are not formed, and the inner ring 83 a is locked to the second lid portion 41 on the surface facing the other side in the axial direction. . As described above, the inner ring 83a is restricted from being displaced in the axial direction on both sides with respect to the output gear 40.

  On the other hand, the outer ring 83 b of the third deep groove ball bearing 83 has a surface facing one side in the axial direction locked with the second housing member 12 and a surface facing the other side in the axial direction locked with the third housing member 13. That is, the outer ring 83 b is restricted from being displaced in the axial direction on both sides with respect to the housing 10. As described above, the third deep groove ball bearing 83 is restricted from being displaced in the axial direction on both sides of the housing 10 and the output gear 40, and the output gear 40 is moved on both sides in the axial direction relative to the housing 10 via the third deep groove ball bearing 83. Displacement is regulated. In this way, the planetary gear device 1 regulates relative displacement of the housing 10, the sun gear 20, the internal gear 30 and the output gear 40 in the axial direction.

  Further, the second needle bearing 72 can roll between the outer peripheral surface of the portion of the output gear 40 where the inner teeth 40 a are formed and the inner peripheral surfaces of the first housing member 11 and the second housing member 12. Is provided. The second needle bearing 72 rotatably supports the output gear 40 with respect to the housing 10. Further, the second needle bearing 72 restricts the output gear 40 from being displaced radially outward by the load received by the output gear 40 from the planetary gear 50 when the output gear 40 meshes with the planetary gear 50. Thereby, the planetary gear device 1 can prevent the output gear 40 from being damaged due to the deformation by suppressing the deformation of the output gear 40 by the second needle bearing 72.

  The inner peripheral surface of the planetary gear 50 is formed such that both end portions in the axial direction are larger in diameter than the central portion in the axial direction. The first needle bearing 71 is provided between the outer peripheral surface of the planetary shaft member 61 and the small-diameter inner peripheral surface 51 formed at the axial center portion of the inner peripheral surface of the planetary gear 50. Further, a pair of thrust ball bearings 90 is provided on both axial sides of the first needle bearing 71, and each thrust ball bearing 90 is an axis line of the outer peripheral surface of the planetary shaft member 61 and the inner peripheral surface of the planetary gear 50. It is provided between the large-diameter inner peripheral surfaces 52 formed at both ends in the direction.

  Both end portions in the axial direction of the planetary shaft member 61 are formed to have a smaller diameter than the central portion inserted into the planetary gear 50, and the collar 62 is attached to the small diameter shaft portions 61 a formed at both end portions in the axial direction of the planetary shaft member 61. It is fitted. The length dimension in the axial direction of the collar 62 is set to be the same as the length dimension in the axial direction of the small-diameter shaft portion 61a.

  Further, a pair of rotating plates 63 formed in an annular plate shape are provided on both sides in the axial direction of the three planetary shaft members 61, and the inner peripheral surface or the second lid portion of the rotating plate 63 and the first lid portion 31. A plurality of third needle bearings 73 are provided between the inner peripheral surface of 41. The pair of rotating plates 63 and the three support members 60 are thrust supported by the first lid 31 and the second lid 41 through a plurality of third needle bearings 73 so as to be integrated with the planetary gear 50. Revolve around the input / output axis A.

  As shown in FIG. 2, the planetary gear device 1 further includes six urging members 100. The biasing member 100 is a rod-shaped spring that connects the two support members 60 together. The urging member 100 has three urging members arranged on both sides of the planetary gear 50 and three collars 62 arranged on one side and the other side of the planetary gear 50 in the axial direction. They are connected by a force member 100.

  Specifically, fitting pieces 101 are formed at both end portions of the urging member 100, and two fitting grooves 62 a that fit into the fitting pieces 101 are formed in the collar 62. The planetary gear device 1 then fits the fitting pieces 101 formed at both end portions of the urging member 100 into the fitting grooves 62a formed in each of the two collars 62 adjacent in the circumferential direction. The two support members 60 adjacent to each other in the circumferential direction are connected to each other.

  In a state in which the three support members 60 are connected by the biasing member 100, the biasing member 100 is supported by each of the support members by the bending elastic force (elastic return in the direction in which the curvature decreases) of the biasing member 100 itself. 60 is urged radially outward. Accordingly, the three planetary gears 50 are urged to the urging member 100 via the support member 60. Therefore, the planetary gear device 1 can maintain the state in which each planetary gear 50 is pressed against the internal gear 30 and the output gear 40, and thus is generated between the planetary gear 50, the internal gear 30, and the output gear 40. Backlash can be reduced.

  In particular, the biasing member 100 biases the three planetary gears 50 toward the output gear 40 via the support member 60. Thereby, since the planetary gear apparatus 1 can reduce the backlash generated between the planetary gear 50 and the output gear 40, the generation of noise can be suppressed.

  Further, the three planetary gears 50 are connected to each other via the three support members 60 and the biasing member 100. Thereby, the planetary gear device 1 has a large load only on one planetary gear 50 when there is a dimensional error in the planetary gear 50 or the sun gear 20 that meshes with the planetary gear 50, the internal gear 30, and the output gear 40. Can be applied, the load applied to one planetary gear 50 can be distributed to the other two planetary gears 50. As a result, the planetary gear device 1 can equalize the load that each planetary gear 50 receives when meshing with the internal gear 30 and the output gear 40. As a result, the planetary gear device 1 can avoid early wear of one planetary gear 50 compared to the other two planetary gears 50.

  In the planetary gear device 1, the support member 60 and the biasing member 100 connect the three planetary gears 50 and support the planetary gears 50 so that they can rotate and revolve around the sun gear 20. To serve as a carrier. The biasing member 100 biases the three planetary gears 50 radially outward via the three support members 60 and maintains the relative positional relationship between the three support members 60 and the three planetary gears 50. Thereby, the planetary gear device 1 can prevent rattling of each planetary gear 50 in the revolution direction.

  Further, the support member 60 is urged radially outward by the urging member 100, and the three planetary gears 50 are pressed against the internal gear 30 and the output gear 40, thereby positioning in the radial direction. In this case, the planetary gear device 1 can eliminate the need for a carrier and a bearing for positioning the support member 60 in the radial direction, so that frictional resistance due to the bearing can be eliminated and the planetary gear device 1 Weight reduction can be achieved.

  Here, the assembly procedure of the support member and the 60 biasing member 100 will be described. The operator assembles the three planetary gears 50 to the sun gear 20, the internal gear 30 and the output gear 40 before assembling the support member 60 and the biasing member 100. Then, the operator inserts the planetary shaft member 61 into each of the three planetary gears 50 that have been assembled, and attaches the collar 62 to the small-diameter shaft portion 61a of the planetary shaft member 61 that projects from both sides of the planetary gear 50 in the axial direction. By mounting, the assembly of the support member 60 is completed. Thereafter, the three collars 62 mounted on one side and the other side of the planetary gear 50 in the axial direction are connected to each other by the three biasing members 100, and the assembly of the biasing member 100 is completed. The housing 10 is assembled after the urging member 100 is assembled.

  As described above, the planetary gear device 1 connects the support members 60 to each other on the outer side in the axial direction of the planetary gear 50. Therefore, after the planetary gear 50 is assembled to the sun gear 20, the internal gear 30, and the output gear 40, the support member 60 60 and the biasing member 100 can be assembled. Therefore, the planetary gear device 1 is assembled as compared with the case where the planetary gear 50 is assembled to the sun gear 20, the internal gear 30, and the output gear 40 with the support member 60 and the biasing member 100 assembled to the planetary gear 50. The work efficiency at the time can be improved.

  The support member 60 includes a planetary shaft member 61 and a collar 62. Then, the operator inserts the planetary shaft member 61 into the assembled planetary gear 50 when the planetary gear device 1 is assembled, and both end sides in the axial direction of the planetary shaft member 61 projecting from both sides of the planetary gear 50 in the axial direction. A collar 62 can be attached to the. Therefore, the operator can easily assemble the support member 60. The urging member 100 connects the urging member 100 to the collar 62 by fitting the fitting pieces 101 formed at both ends of the urging member 100 into the fitting grooves 62 a formed in the collar 62. it can. In this case, the planetary gear device 1 can assemble the urging member 100 without using a jig or the like, so that it is possible to improve work efficiency at the time of assembly.

  In the planetary gear device 1, a leaf spring is used as a spring used for the biasing member 100. In this case, the planetary gear device 1 can reduce the space required for the arrangement of the urging member 100, so that the planetary gear device 1 can be reduced in size.

(1-2: Operation of the planetary gear unit 1)
Next, the operation of the planetary gear device 1 will be described. As shown in FIGS. 1 and 2, the planetary gear device 1 is a reduction device that decelerates the rotation input to the input shaft member 2 and outputs it from the output gear 40.

  Specifically, when rotation is input to the input shaft member 2, the sun gear 20 integrally formed with the input shaft member 2 rotates about the input / output axis A. Each planetary gear 50 meshing with the sun gear 20 revolves around the sun gear 20 while rotating. The output gear 40 rotates around the input / output axis A while meshing with the three planetary gears. Then, the planetary gear device 1 outputs the rotation component of the output gear 40.

  Here, each planetary gear 50 is rotatably supported by the planetary shaft member 61 via the first needle bearing 71. Therefore, when each planetary gear 50 revolves around the sun gear 20 while rotating, the support member 60 and the biasing member 100 revolve around the sun gear 20 as the three planetary gears 50 revolve. At this time, the pair of rotating plates 63 rotate integrally with the support member 60 and the biasing member 100. Since the pair of rotating plates 63 is thrust-supported with respect to the first lid portion 31 and the second lid portion 41 via the third needle bearing 73, the planetary gear device 1 includes the planetary gear 50, the support The member 60 and the biasing member 100 can be smoothly rotated.

  Further, the biasing member 100 is connected to the planetary gear 50 to which the last power is transmitted in the power transmission path of the planetary gear device 1 in which the rotation input to the input shaft member 2 is decelerated and output from the output gear 40. Backlash generated between the gear 40 and the gear 40 is reduced. As a result, the planetary gear device 1 can increase the positioning accuracy of the output gear 40 in the rotation direction and can suppress the generation of noise. In addition to this, the planetary gear device 1 is a reduction device that uses the output gear 40 as an internal gear, and the biasing member 100 biases the planetary gear 50 toward the output gear 40 via the support member 60. Generation of noise can be effectively suppressed.

<2. Second embodiment>
Next, a second embodiment will be described. In the first embodiment, the case where the biasing member 100 is three springs that connect the three collars 62 has been described. On the other hand, the biasing member 300 in the second embodiment is one spring formed in an endless shape. In addition, the same code | symbol is attached | subjected to the components same as above-mentioned 1st embodiment, and the description is abbreviate | omitted.

(2-1: Schematic configuration of planetary gear device 201)
First, the configuration of the planetary gear device 201 will be described with reference to FIG. As shown in FIG. 3, the planetary gear device 201 in the second embodiment has a configuration equivalent to that of the planetary gear device 1 in the first embodiment, except for the support member 260 and the biasing member 300. The support member 260 is formed in a cylindrical shape having the same outer diameter over the entire axial direction.

(2-2: Energizing member 300)
Next, the urging member 300 will be described with reference to FIG. In addition, illustration of the housing is abbreviate | omitted in FIG. As shown in FIG. 4, the biasing member 300 is a ring-shaped endless spring. The urging member 300 includes an arc-shaped grip portion 301 formed following the outer peripheral surface shape of the support member 260 and a connecting portion 302 that connects two grip portions 301 adjacent in the circumferential direction. Three are provided at intervals. Each grip portion 301 grips the outer peripheral surface of both side portions in the axial direction of the support member 260 from the radially inner side as viewed from the input / output axis A, and the bending elastic force (curvature becomes small) of each connecting portion 302. The elastic members are biased outward in the radial direction of each support member 260 by elastic return in the direction).

  Thus, each of the three planetary gears 50 is urged outward in the radial direction by urging each of the three support members 260 held by the holding portion 301 in the radial direction. Is done. Therefore, the planetary gear device 201 can maintain the state in which each planetary gear 50 is pressed against the internal gear 30 and the output gear 40, and thus is generated between the planetary gear 50 and the internal gear 30 and the output gear 40. Backlash can be reduced. As a result, the planetary gear device 201 can improve the positioning accuracy of the output gear 40 in the rotation direction.

  Further, the three support members 260 are connected by the biasing member 300. Therefore, the planetary gear unit 201 has a large load only on one planetary gear 50 when there is a dimensional error in the planetary gear 50 or the sun gear 20 that meshes with the planetary gear 50, the internal gear 30, and the output gear 40. Even if added, the load applied to one planetary gear 50 can be distributed to the other two planetary gears 50. As a result, the planetary gear device 201 can equalize the load that each planetary gear 50 receives when meshing with the internal gear 30 and the output gear 40.

  Further, since the planetary gear device 201 is urged radially outward in a state where the three planetary gears 50 are connected by the urging member 300, the planetary gears 50 are not rattled in the revolution direction. Can be prevented.

  Further, the urging member 300 is attached to both end portions of the axis elevation of the support member 260 protruding from both end portions in the axial direction across the planetary gear 50. That is, since the biasing member 300 connects the three support members 260 on the outer side in the axial direction of the planetary gear 50, the planetary gear device 201 assembles the biasing member 300 in a state where the planetary gear 50 is assembled. Therefore, it is possible to improve the work efficiency at the time of assembly. Further, since the urging member 300 is one endless spring, the planetary gear device 201 can easily assemble the urging member 300 and improve work efficiency during the assembly. Can be achieved.

<3. Other>
Although the present invention has been described based on the above embodiments, the present invention is not limited to the above embodiments, and various modifications and improvements can be made without departing from the spirit of the present invention. It can be easily guessed.

  For example, in each of the above embodiments, the case where the output gear 40 is an internal gear has been described, but the output gear may be an external gear. In this case, the length of the sun gear in the axial direction is made shorter than in the above embodiments, and the output gear is arranged side by side with the sun gear. In this case, since the urging member can urge the planetary gear 50 toward the output gear by urging the planetary gear 50 radially inward, it is generated between the planetary gear 50 and the output gear. Can reduce backlash.

  In the first embodiment described above, the case where the support member 60 includes the planetary shaft member 61 and the collar 62 and the planetary gear 50 is rotatably supported with respect to the planetary shaft member 61 has been described. It is not something that can be done. For example, the planetary gear and the planetary shaft member may be integrally formed, and the collar as the support member may be rotatably supported with respect to the planetary gear and the planetary shaft member. As a result, the planetary gear and the planetary shaft member are supported by the collar so as to be able to rotate and revolve around the sun gear 20, and the biasing member 100 connected to the collar and the collar includes the planetary gear and the planetary shaft. Rotates as the member revolves.

  Similarly, in the above-described second embodiment, the case where the planetary gear 50 is rotatably supported with respect to the support member 260 has been described. However, the present invention is not necessarily limited to this, and the planetary gear and the support member are integrated. The biasing member 300 may be formed and slidably support the support member.

  In each of the embodiments described above, the case where the pair of biasing members 100 are provided on both sides in the axial direction across the planetary gear 50 has been described. At least one side). Moreover, although said 1st embodiment demonstrated the case where the urging | biasing member 100 was a leaf | plate spring, you may use a coil spring etc. instead of a leaf | plate spring.

  1, 201: planetary gear device, 20: sun gear, 30: internal gear, 40: output gear, 50: planetary gear, 60, 260: support member, 100, 300: biasing member, 301: gripping part

Claims (7)

An internal gear that is an internal gear;
A sun gear that is an external gear arranged coaxially with the internal gear;
A plurality of planetary gears that are external gears that revolve around the sun gear while meshing with the internal gear and the sun gear;
The internal gear and the sun gear are internal gears or external gears having different numbers of teeth, mesh with the plurality of planetary gears, coaxial with the internal gear and the sun gear, and the internal gear. And an output gear arranged to be rotatable relative to the sun gear;
A biasing member that couples the plurality of support members and biases each of the plurality of support members in a radial direction;
A planetary gear device comprising:   The planetary gear device according to claim 1, wherein the biasing member biases the plurality of planetary gears toward the output gear via the plurality of support members. The planetary gear device is a reduction gear having the output gear as an internal gear,
The planetary gear device according to claim 2, wherein the biasing member biases the support member radially outward.   The planetary gear device according to any one of claims 1 to 3, wherein the urging member connects the plurality of support members on the outer side in the axial direction than the planetary gear.   The planetary gear device according to claim 4, wherein the urging member is provided on both sides in the axial direction of the planetary gear.   The planetary gear device according to any one of claims 1 to 5, wherein the biasing member is a plurality of springs that connect two of the plurality of support members to each other.   The planetary gear device according to any one of claims 1 to 5, wherein the urging member is an endless spring including a plurality of grip portions that grip each of the plurality of support members.

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