JP2017214947A - Gear reducer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrict the flexure due to an angular moment applied to a carrier pin while stably supporting the carrier pin in an eccentric oscillation type gear reducer.SOLUTION: A gear reducer 1 comprises: an input shaft 11 rotating about a rotation axis 90 at an input rotational speed; an output part rotating at an output rotational speed slower than the input rotational speed; an eccentric body 13 fixed to the periphery of the input shaft; a plurality of external tooth gears 20 having a plurality of external teeth in the periphery; a plurality of eccentric body bearings 30 for rotatably supporting the external tooth with respect to the input shaft; an internal gear 40 having a plurality of internal teeth meshing with the external teeth; a plurality of carrier pins 50 extending in an axial direction; a carrier 60 disposed between the plurality of external tooth gears in the axial direction; a carrier bearing 33 disposed between the carrier and the input shaft in the radial direction for rotatably supporting the carrier to the input shaft; and a flange 70 rotating together with the output part. The plurality of carrier pins are fixed to the carrier and the flange or to the external tooth gear.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a gear reducer.

  Conventionally, an eccentric oscillating gear reducer using a planetary gear mechanism is known. In such a gear reducer, the external gear is inscribed in mesh with the internal gear, and the external gear is swung by an input shaft which is an eccentric body rotatably supported by the external gear. Thus, the external gear rotates while revolving around the input shaft. Then, the rotation of the external gear is transmitted to the output shaft, whereby the rotation of the input shaft is decelerated and output to the output shaft.

  A conventional gear reducer is described in, for example, Japanese Patent Publication No. 5-26053. The gear reducer described in the document includes an input shaft provided with an eccentric body, an external gear that is oscillated and rotated by the eccentric body, and an internal gear in which a meshing portion of the external gear is configured by an external pin. ing. The eccentric body is fitted to the external gear through a bearing. An inner pin is loosely fitted in the inner pin hole of the external gear. One side of the inner pin in the axial direction is supported by a flange formed integrally with the output shaft. The other side of the inner pin in the axial direction is supported by a support ring. The number of external teeth of the external gear is smaller than the number of external pins that are internal teeth of the internal gear.

  In the gear reducer described in the document, the input shaft is supported by two bearings. Among these, the input side bearing is supported by a cover. Moreover, the cover is being fixed to the main body of the internal gear which comprises the casing of a gear reducer. Thus, it is described that the rotation of the input shaft can be decelerated and output to the output shaft as the rotation component of the external gear that oscillates and rotates.

Japanese Patent Publication No. 5-26053

  However, in the gear reducer described in this document, one end of the inner pin, which is a carrier pin, is fixed to the flange on the output side, and the other end is fixed to a support ring arranged on the input side. Yes. For this reason, when the two external gears are separated in the axial direction and oscillated in opposite phases to each other, a rotation moment in a direction perpendicular to the rotation axis is generated in the carrier pin that supports the external gear. When the rotational moment is generated, the carrier pin is bent. As a result, there is a possibility that the reduction of the efficiency of the gear reducer, rattling during operation, wear of the carrier pin, and the like may occur.

  In particular, in consideration of the reduction in size and weight of the gear reducer, it is assumed that the inner pin is made thinner and that resin or the like is used as the material for the carrier pin. Then, there is a concern that the influence of the bending of the carrier pin due to the rotational moment becomes larger due to the decrease in the rigidity of the carrier pin.

  An object of the present invention is to provide a technique capable of stably supporting a carrier pin and suppressing bending due to a rotational moment acting on the carrier pin in an eccentric rocking type gear reducer.

  An exemplary first invention of the present application is an eccentric oscillating gear speed reducer, which is disposed behind an input shaft that rotates at an input rotational speed around a rotating shaft extending in the front-rear direction. An output section that rotates at an output rotational speed that is lower than the input rotational speed around the rotational axis, an eccentric body that is fixed to an outer peripheral portion of the input shaft, and a radially outer side of the input shaft. A plurality of external gears arranged and having a plurality of external teeth on the outer periphery, and a plurality of eccentric body bearings fixed to the outer periphery of the eccentric body and rotatably supporting the external gear with respect to the input shaft An internal gear having a plurality of internal teeth meshing with the external teeth, a plurality of carrier pins extending in the axial direction, a carrier disposed between the plurality of external gears in the axial direction, the carrier and the input Arranged between the shaft and the radial direction Is has a carrier bearing for rotatably supporting the carrier with respect to said input shaft, and a flange that rotates together with the output portion, a plurality of the carrier pins are fixed to the carrier and the flange.

  According to the first exemplary invention of the present application, the plurality of carrier pins are supported by carriers arranged between adjacent external gears. For this reason, the moment which acts on a carrier pin with the rotational movement of an external gear becomes small. As a result, the swinging motion of the external gear can be stabilized.

FIG. 1 is a longitudinal sectional view of a gear reducer according to the first embodiment. FIG. 2 is a cross-sectional view of the gear reducer according to the first embodiment. FIG. 3 is a cross-sectional view of the gear reducer according to the first embodiment. FIG. 4 is a cross-sectional view of the gear reducer according to the first embodiment. FIG. 5 is a longitudinal sectional view of a gear reducer according to a modification. FIG. 6 is a cross-sectional view of a gear reducer according to a modification. FIG. 7 is a longitudinal sectional view of a gear reducer according to a modification.

  Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. In the present application, a direction parallel to the rotation axis is referred to as an “axial direction”, a direction orthogonal to the rotation axis is referred to as a “radial direction”, and a direction along an arc centered on the rotation axis is referred to as a “circumferential direction”. However, the above “parallel direction” includes a substantially parallel direction. In addition, the above-mentioned “orthogonal direction” includes a substantially orthogonal direction. Hereinafter, the input shaft side in FIG. 1 is referred to as “axially forward”, and the output shaft side in FIG. 1 is referred to as “axially rearward”. However, these directions are not intended to limit the direction of use of the gear reducer according to the present invention.

<1. First Embodiment>
FIG. 1 is a longitudinal sectional view of the gear reducer 1 according to the first embodiment of the present invention cut along a plane including a rotating shaft 90. 2 and 3 are cross-sectional views of the gear reducer 1 viewed from the position AA in FIG. FIG. 4 is a cross-sectional view of the gear reducer 1 viewed from the BB position in FIG.

  The gear speed reducer 1 is an inscribed planetary speed reducer, and the rotational motion of the first rotational speed (input rotational speed) is the rotational motion of the second rotational speed (output rotational speed) lower than the first rotational speed. This is an eccentric oscillating gear speed reducer. The gear reducer 1 is used by being incorporated in a drive mechanism such as a robot, a machine tool, an XY table, a material cutting device, a conveyor line, a turntable, a rolling roller, or the like. However, the speed reducer of the present invention may be used for other purposes.

  As shown in FIG. 1, the gear reducer 1 of this embodiment includes an input shaft 11, an output shaft 12, an eccentric body 13, a plurality of external gears 20, a plurality of eccentric body bearings 30, an internal gear 40, and a plurality of gears. A carrier pin 50, a carrier 60, a carrier bearing 33, and a flange 70 are provided.

  The input shaft 11 is a cylindrical member that rotates at a first rotation speed that is a rotation speed input from the outside. The input shaft 11 is disposed along the rotation axis 90. The axially forward end of the input shaft 11 is connected to a motor, which is a drive source, directly or via another power transmission mechanism. When the motor is driven, the input shaft 11 rotates at the first rotation speed around the rotation shaft 90.

  An eccentric body 13 is fixed to the outer peripheral portion of the input shaft 11. The eccentric body 13 includes a first eccentric portion 131 and a second eccentric portion 132 positioned rearward in the axial direction from the first eccentric portion 131. The first eccentric portion 131 has a cylindrical outer peripheral surface centering on a first rotation shaft 91 extending parallel to the rotation shaft 90 at a position deviated from the rotation shaft 90. The second eccentric portion 132 also has a cylindrical outer peripheral surface centering on a second rotation shaft 92 extending parallel to the rotation shaft 90 at a position off the rotation shaft 90. The first rotation shaft 91 and the second rotation shaft 92 are located on opposite sides of the rotation shaft 90. That is, the first rotating shaft 91 and the second rotating shaft 92 are positioned so as to be rotationally symmetric about the rotating shaft 90 when viewed from the axial direction. When the input shaft 11 rotates, the positions of the first rotating shaft 91 and the second rotating shaft 92 also rotate around the rotating shaft 90.

  The output shaft 12 is an output unit that rotates at a second rotational speed about the rotation shaft 90. The output shaft 12 is a columnar member that is disposed axially rearward from the input shaft 11 along the rotation axis 90.

  The external gear 20 is disposed on the radially outer side of the input shaft 11. In the present embodiment, the gear reducer 1 has two external gears 20, that is, a first external gear 21 and a second external gear 22.

  The eccentric body bearing 30 is fixed to the outer peripheral portion of the eccentric body 13 and supports the external gear 20 so as to be rotatable with respect to the input shaft 11. The eccentric bearing 30 of the present embodiment uses a ball bearing that rotates the external gear 20 and the eccentric 13 through a sphere.

  The first external gear 21 is attached to the outer peripheral surface of the first eccentric portion 131 via the eccentric body bearing 30. Accordingly, the first external gear 21 is supported rotatably about the first rotation shaft 91 of the first eccentric portion 131. The second external gear 22 is attached to the outer peripheral surface of the second eccentric portion 132 via the eccentric body bearing 30 at the rear of the first external gear 21 in the axial direction. Therefore, the second external gear 22 is supported rotatably about the second rotation shaft 92 of the second eccentric portion 132.

  As shown in an enlarged manner in FIG. 2, the first external gear 21 has a plurality of external teeth 23 protruding outward in the radial direction on the outer peripheral portion thereof. In addition, an inter-external tooth groove 24 that is recessed radially inward is provided between adjacent external teeth 23. The external teeth 23 and the inter-external teeth grooves 24 are alternately arranged in the circumferential direction around the first rotation shaft 91. Similarly to the first external gear 21, the second external gear 22 also has a plurality of external teeth 23 and a plurality of external tooth grooves 24 on the outer peripheral portion.

  As shown in FIGS. 1 and 2, the first external gear 21 has a plurality of (eight in the example of FIG. 2) pin holes 25. The plurality of pin holes 25 are arranged at equal intervals in the circumferential direction around the first rotation shaft 91. Each pin hole 25 penetrates the first external gear 21 in the axial direction on the radially inner side of the external teeth 23 and the inter-external teeth groove 24. The second external gear 22 also has a plurality of pin holes 25, as with the first external gear 21.

  The internal gear 40 is a substantially cylindrical member disposed on the outer side in the radial direction of the external gear 20. As shown in FIG. 1, the gear reducer 1 according to the present embodiment includes a rear lid portion 41 that extends radially inward from the axially rear end portion of the internal gear 40. At least a part of the rear surface in the axial direction of the internal gear 40 is covered by the rear lid portion 41. Further, the gear reducer 1 of the present embodiment has a front lid portion 42 that is fixed to the front end portion in the axial direction of the internal gear 40. At least a part of the front surface in the axial direction of the internal gear 40 is covered by the front lid portion 42. A bearing 31 is interposed between the input shaft 11 and the front lid portion 42. Thereby, the input shaft 11 is rotatably supported with respect to the front lid part 42. In addition, the internal gear 40 and the rear cover part 41 may be comprised by the single member, and another member may be sufficient as it.

  As shown in an enlarged manner in FIG. 2, the internal gear 40 has a plurality of internal teeth 43 that protrude radially inward on the inner peripheral portion thereof. Further, between the adjacent internal teeth 43, an internal inter-tooth groove 44 that is recessed outward in the radial direction is provided. The inner teeth 43 and the inner inter-tooth grooves 44 are alternately arranged in the circumferential direction around the rotation shaft 90.

  The plurality of external teeth 23 of the external gears 21 and 22 and the plurality of internal teeth 43 of the internal gear 40 mesh with each other. That is, during the operation of the gear reducer 1, the external teeth 23 of the external gears 21 and 22 are fitted into the internal gear grooves 44 of the internal gear 40, and the internal gear grooves 24 of the external gears 21 and 22 are internally connected. While the internal teeth 43 of the tooth gear 40 are fitted, the external gears 21 and 22 rotate. The internal teeth 43 may be a separate member from the internal gear 40. That is, an internal gear may be comprised by providing the internal teeth of another member in the inner peripheral part of an annular member.

  The first external gear 21 and the second external gear 22 rotate by meshing with the internal teeth 43 of the internal gear 40 while revolving around the rotation shaft 90 by the power of the input shaft 11. Here, the number of internal teeth 43 included in the internal gear 40 is larger than the number of external teeth 23 included in each of the first external gear 21 and the second external gear 22. For this reason, the position of the external tooth 23 which meshes with the internal tooth 43 of the same position of the internal gear 40 shifts for each revolution of the external gears 21 and 22. As a result, the first external gear 21 and the second external gear 22 rotate in the direction opposite to the rotation direction of the input shaft 11 at a second rotation speed lower than the first rotation speed. Therefore, the position of the pin hole 25 of each external gear 21, 22 also rotates at the second rotational speed.

  When the number of external teeth 23 included in each of the first external gear 21 and the second external gear 22 is N and the number of internal teeth 43 included in the internal gear 40 is M, the reduction ratio P of the gear reducer 1 Is P = (first rotational speed) / (second rotational speed) = N / (MN). In the example of FIG. 2, since N = 58 and M = 60, the reduction ratio in this example is P = 29. That is, the second rotation speed is 1/29 of the first rotation speed. However, the reduction ratio of the speed reduction mechanism in the present invention may be another value.

  FIG. 3 is a diagram in which a second external gear 22 is added by a broken line to the transverse cross-sectional view of the gear reducer 1 viewed from the position AA in FIG. 1 for easy understanding. As shown in an enlarged manner in FIG. 3, θ is the straight line connecting the first rotation shaft 91 and the rotation shaft 90, which is the center of the first external gear 21, and the center of the second external gear 22. This is an angle around the rotation axis 90 formed by the straight line connecting the second rotation axis 92 and the rotation axis 90. In the present embodiment, assuming that the number of external gears 20 is N1, the relationship θ = 360 ° / N1 is satisfied. That is, in the present embodiment, since the number of external gears 20 is two, N1 = 2 and θ = 180 °. If the number of external gears 20 is three, for example, N1 = 3 and θ = 120 °.

  The flange 70 is an annular portion disposed perpendicular to the rotation shaft 90. The flange 70 is disposed rearward in the axial direction with respect to the first external gear 21 and the second external gear 22. In the present embodiment, the flange 70 and the output shaft 12 are formed of a single member. For this reason, the flange 70 rotates around the rotation shaft 90 together with the output shaft 12. However, the flange 70 and the output shaft 12 may be separate members fixed to each other.

  Near the center of the flange 70, a recess 71 is provided that is recessed rearward in the axial direction. The axially rear end of the input shaft 11 is disposed in the recess 71. A bearing 32 is interposed between the flange 70 and the input shaft 11. As a result, the flange 70 is rotatably supported relative to the input shaft 11. Further, by supporting the input shaft 11 by the bearing 32, the rotation of the input shaft 11 can be stabilized. As a result, the rotation of the eccentric body 13 and the external gear 20 can be stabilized, and the moment acting on the carrier pin 50 can be reduced.

  The flange 70 is provided with a plurality (eight in this embodiment) of press-fit holes 72 for press-fitting a plurality of carrier pins 50. The plurality of press-fit holes 72 are arranged at equal intervals in the circumferential direction around the rotation shaft 90. Each press-fit hole 72 passes through the flange 70 in the axial direction.

  The carrier 60 is an annular member arranged perpendicular to the rotation shaft 90. The carrier 60 is disposed between the first external gear 21 and the second external gear 22 in the axial direction. A carrier bearing 33 is interposed between the carrier 60 and the input shaft 11 in the radial direction. Thereby, the carrier 60 is supported so as to be relatively rotatable with respect to the input shaft 11.

  As the carrier bearing 33 of the present embodiment, a ball bearing that rotates the external gear 20 and the eccentric body 13 via a sphere is used. In the present embodiment, the inner peripheral surface of the carrier bearing 33 is positioned on the radially outer side than the inner peripheral surface of the eccentric body bearing 30. Thereby, the carrier bearing 33 can be easily assembled from the axial direction. As a result, the gear reducer can be easily assembled.

  As shown in FIGS. 1 and 4, the carrier 60 of the present embodiment is provided with a plurality (eight in this embodiment) of fixing holes 61 for inserting a plurality of carrier pins 50. The plurality of fixing holes 61 are arranged at equal intervals in the circumferential direction around the rotation shaft 90. The fixing hole 61 penetrates the carrier 60 in the axial direction.

  The plurality of carrier pins 50 are cylindrical members that extend in the axial direction through the plurality of pin holes 25 of the first external gear 21 and the second external gear 22. As shown in FIG. 2, a gap 54 is interposed between the surface constituting each pin hole 25 and the outer peripheral surface of the carrier pin 50. When the first external gear 21 and the second external gear 22 rotate at the second rotational speed after deceleration, the power is transmitted to the carrier pins 50 through the gaps 54.

  The axially rear ends of the plurality of carrier pins 50 are inserted into the press-fit holes 72 of the flange 70. The plurality of carrier pins 50 are also fixed to the carrier 60 by being press-fitted into the fixing holes 61 of the carrier 60. For this reason, the plurality of carrier pins 50, the flange 70, the carrier 60, and the output shaft 12 rotate at the second rotation speed around the rotation shaft 90. The carrier 60 and the plurality of carrier pins 50 may be separate members or a single member. If the carrier 60 and the plurality of carrier pins 50 are a single member, the number of parts for constituting the gear reducer can be reduced.

  Thus, the carrier pin 50 of the present embodiment is fixed to the carrier 60 and the flange 70. That is, the plurality of carrier pins 50 are supported by the carrier 60 disposed between the first external gear 21 and the second external gear 22. For this reason, the moment which acts on the carrier pin 50 with the rotational movement of the external gear 20 can be reduced, and the bending of the carrier pin 50 can be suppressed. As a result, the swinging motion of the external gear can be stabilized, and the reduction in efficiency of the gear reducer, rattling during operation, wear of the carrier pin, and the like can be suppressed.

  In particular, considering the weight reduction of the gear reducer 1, when the carrier pin 50 is made of a light material, it is assumed that the rigidity of the carrier pin 50 is reduced. However, in the gear reducer 1 of the present embodiment, the moment acting on the carrier pin 50 can be suppressed by supporting the carrier pin 50 with the carrier 60. As a result, a low-rigidity material such as a resin material can be applied to the carrier pin 50, and the weight reduction of the gear reducer 1 can be realized.

<2. Modification>
As mentioned above, although exemplary embodiment of this invention was described, this invention is not limited to said embodiment. Hereinafter, various modifications will be described focusing on differences from the above-described embodiment.

  FIG. 5 is a longitudinal sectional view of the gear reducer 1A according to the modification, cut along a plane including the rotation shaft 90A. FIG. 6 is a cross-sectional view of the gear reducer 1A viewed from the CC position in FIG. The gear reducer 1A is an eccentric oscillating type that converts the rotational motion of the first rotational speed applied to the input shaft 11A by the driving force of the motor into the rotational motion of the second rotational speed lower than the first rotational speed. Gear reducer. The gear reducer 1A further includes a lid portion 42A and a motor 80A.

  The lid part 42A has a disc part 421A and an annular part 422A. The disc portion 421A extends radially inward from the vicinity of the end portion on the axially front side of the internal gear 40A. The disc part 421A covers at least a part of the front surface in the axial direction of the carrier pin 50A and the external gear 20A. The annular portion 422A extends in a cylindrical shape centering on the rotation shaft 90 from the outer peripheral portion of the disc portion 421A toward the front in the axial direction.

  The motor 80A has a rotor magnet 81A and an armature 82A. The rotor magnet 81A is arranged in front of the disk portion 421A in the axial direction and on the radially outer side of the input shaft 11A. In this embodiment, the rotor magnet 81A is fixed to the input shaft 11A via a connection portion 811A fixed to the outer peripheral surface of the input shaft 11A. However, the rotor magnet 81A may be directly fixed to the outer peripheral surface of the input shaft 11A. The rotor magnet 81A rotates around the rotation shaft 90A together with the input shaft 11A.

  The armature 82A is fixed to the inner peripheral portion of the annular portion 422A and overlaps the rotor magnet 81A in the radial direction. When the motor 80A is driven, a drive current is supplied to the armature 82A from an external power supply (not shown). As a result, a magnetic flux is generated in the armature 82A. A circumferential torque is generated by the action of the magnetic flux between the armature 82A and the rotor magnet 81A. As a result, the input shaft 11A rotates at the first rotation speed around the rotation shaft 90A. If it does in this way, a motor can be built in a gear reducer and a gear reducer can be reduced in size.

  The motor 80A shown in FIG. 5 is a so-called inner rotor type motor in which the rotor magnet 81A is disposed inside the armature 82A in the radial direction. However, the motor may be a so-called outer rotor side motor in which the rotor magnet is disposed outside the radial direction of the armature. In this case, the armature is fixed to the outer peripheral portion of the annular portion, and the rotor magnet may be disposed so as to face the radially outer surface of the armature via the connection portion.

  Further, as shown in FIGS. 5 and 6, the plurality of carrier pins 50A of the present embodiment are fixed to the pin holes 25A of the external gear 20A. The carrier pin 50A fixed to the first external gear 21A and the carrier pin 50A fixed to the second external gear 22A are separate members. Thereby, the axial length of the carrier pin 50A can be suppressed, and the gear reducer can be reduced in weight. In addition, the several carrier pin and external gear of this embodiment may be comprised by the single member. Thereby, a number of parts can be reduced and a gear reduction gear can be reduced in size and weight.

  Further, as shown in FIG. 5, the plurality of carrier pins 50A are arranged through a gap 54A in a through hole 72A that penetrates the flange 70A in the axial direction and a through hole 61A that penetrates the carrier 60A in the axial direction. The Even with such a structure, a gear reducer can be configured.

  Further, the eccentric body 13A of the present embodiment is composed of a plurality of members. The plurality of eccentric bodies 13A are respectively disposed between the plurality of external gears 20A and the radial direction of the input shaft 11A. In this way, the eccentric body 13A can be disposed only between the input shaft 11A and the external gear 20A. Therefore, the axial width of the eccentric body can be reduced. As a result, the gear reducer can be further reduced in size and weight.

  FIG. 7 is a longitudinal sectional view of a gear reducer 1B according to another modification, cut along a plane including the rotation shaft 90B. The gear reducer 1B is a compound reducer that reduces the rotational motion of the input shaft 11C by the reducer 1C and transmits the reduced speed to the input shaft 11B as the first rotational speed. The gear reducer 1B further includes an input shaft 11C and a reducer 1C.

  The input shaft 11C is a columnar member that is disposed in front of the input shaft 11B and extends along the rotation shaft 90B. An end portion in the axial direction of the input shaft 11C is connected to a motor as a drive source directly or via another power transmission mechanism. When the motor is driven, the input shaft 11C rotates about the rotation shaft 90B.

  The speed reducer 1C is a speed reducer that converts the rotational motion of the input shaft 11C into the rotational motion and the revolving motion of the ball member 15C and transmits the rotational motion to the input shaft 11B. However, the speed reducer 1C may use another system such as an inscribed planetary system. The reduction gear 1C of the present embodiment includes a lid portion 42C, a ball member 15C, a fixed ring 16C, a movable ring 17C, a spring member 18C, and a carrier member 19C.

  The lid portion 42C is a member that extends radially inward from the vicinity of the rear end portion in the axial direction of the annular portion 422B. Each component of the reduction gear 1C and a part of the input shaft 11C are accommodated inside the annular portion 422B and the lid portion 42C. The ball member 15C is a spherical member disposed on the outer peripheral portion of the input shaft 11C. The ball member 15C revolves around the rotation shaft 90B while rotating on the outer periphery of the input shaft 11C.

  The fixed ring 16C and the movable ring 17C are annular members disposed on the inner peripheral portion of the annular portion 422B. The fixing ring 16C is fixed to the inner peripheral portion of the annular portion 422B. The movable ring 17C is disposed in front of the fixed ring 16C in the axial direction. The movable ring 17C is movable in the axial direction.

  The spring member 18C is a member that pressurizes the movable ring 17C rearward in the axial direction. The spring member 18C is an annular member that expands and contracts in the axial direction. The spring member 18C is disposed between the lid portion 42C and the movable ring 17C in a state compressed in the axial direction rather than the natural length. For this reason, the movable ring 17C is pressurized rearward in the axial direction by the repulsive force of the spring member 18C. The fixed ring 16C and the movable ring 17C are in contact with the outer peripheral surface of the ball member 15C. For this reason, when the movable ring 17C is pressurized forward in the axial direction, the ball member 15C receives a pressing force toward the radially inner side.

  The carrier member 19C is fixed to the input shaft 11B, and rotates around the rotation shaft 90B as the ball member 15C revolves. When the ball member 15C revolves at the speed after deceleration, the carrier member 19C also rotates at the speed after deceleration about the rotation shaft 90. When the carrier member 19C rotates, the input shaft 11B fixed to the carrier member 19C also rotates at the rotation speed after deceleration around the rotation shaft 90B. Thereby, the rotational motion of the input shaft 11C is converted into a rotational motion having a rotational speed lower than the rotational speed of the input shaft 11C, and is output to the input shaft 11B as the first rotational speed. In this way, by configuring the compound speed reducer, vibration and noise of the gear speed reducer can be reduced.

  In the above embodiment, the gear reducer has two external gears. However, the number of external gears 20 included in the gear reducer may be three or more. And the number N1 of external gears and the number N2 of carriers should just satisfy | fill the relationship of N2 = N1-1. Thereby, even if there are three or more external gears, the carrier pin can be supported by the carrier disposed between the adjacent external gears. Moreover, the moment which acts on a carrier pin can be made smaller by providing the number of external gears three or more. Even when there are three or more external gears, the centers of the external gears are positioned so as to be rotationally symmetric about the rotation axis when viewed from the axial direction.

  In the above embodiment, ball bearings are used for the respective bearings. However, in place of the ball bearing, other types of bearings such as a slide bearing and a fluid bearing may be used for each bearing.

  Moreover, in said embodiment, the output part was comprised by the output shaft. However, the output unit may be, for example, a disk unit that rotates about the rotation axis, or may be configured by other than the output shaft.

  Moreover, about the detailed shape of a gear reducer, you may differ from the shape shown by each figure of this application. Moreover, you may combine suitably each element which appeared in said embodiment and modification in the range which does not produce inconsistency.

  The present invention can be used for a gear reducer.

1, 1A, 1B Gear reducer 1C Reducer 11, 11A, 11B Input shaft 11C Input shaft 12, 12A Output shaft 13, 13A Eccentric body 15C Ball member 16C Fixed ring 17C Movable ring 18C Spring member 19C Carrier member 20, 20A Outside Toothed gears 21, 21A First external gears 22, 22A Second external gears 23 External teeth 24 External gear grooves 25, 25A Pin holes 30 Eccentric body bearings 31, 32 Bearings 33 Carrier bearings 40, 40A Internal gears 41 Rear Lid part 42, 42A, 42C Lid part 421A Disc part 422A, 422B Ring part 43 Inner tooth 44 Internal inter-tooth groove 50, 50A Carrier pin 54, 54A Clearance 60, 60A Carrier 61 Fixing hole 61A Through hole 70, 70A Flange 71 Concave 72 Press-fit hole 72A Through hole 80A Motor 81A Rotor magnet 82A Electric Child 90, 90A, 90B rotary shaft 91 first rotation shaft 92 second rotation shaft 131 first eccentric portion 132 second eccentric portion 811A connecting portion

Claims (11)

An eccentric oscillating gear reducer,
An input shaft that rotates at an input rotational speed around a rotation axis extending in the front-rear direction,
An output unit disposed behind the input shaft and rotating around the rotation axis at an output rotational speed lower than the input rotational speed;
An eccentric body fixed to the outer periphery of the input shaft;
A plurality of external gears arranged on the outside in the radial direction of the input shaft and having a plurality of external teeth on the outer periphery;
A plurality of eccentric body bearings fixed to the outer peripheral portion of the eccentric body and rotatably supporting the external gear with respect to the input shaft;
An internal gear having a plurality of internal teeth meshing with the external teeth;
A plurality of carrier pins extending in the axial direction;
A carrier disposed between the plurality of external gears in the axial direction;
A carrier bearing disposed between the carrier and the input shaft in a radial direction and supporting the carrier rotatably with respect to the input shaft;
A flange that rotates with the output section;
Have
A plurality of the carrier pins are gear reducers fixed to the carrier and the flange or the external gear. The gear reducer according to claim 1,
The external gear has a plurality of pin holes,
The plurality of carrier pins are gear reducers that pass through the pin holes and are fixed to the carrier and the flange. The gear reducer according to claim 1,
The plurality of carrier pins are gear reducers fixed to the external gear. The gear reducer according to any one of claims 1 to 3, wherein
An angle θ about the rotation axis, which is formed by a straight line connecting the centers of the plurality of external gears and the rotation shaft, is θ = 360 ° / N1, where N1 is the number of the external gears. Gear reducer that satisfies the relationship. The gear reducer according to any one of claims 1 to 4, wherein
The number of external gears is three or more,
The number N1 of the external gears and the number N2 of the carriers are gear reducers that satisfy a relationship of N2 = N1-1. A gear reducer according to any one of claims 1 to 5,
An inner peripheral surface of the carrier bearing is a gear reducer located on a radially outer side than an inner peripheral surface of the eccentric body bearing. The gear reducer according to any one of claims 1 to 6,
The rear end portion of the input shaft is a gear reducer connected to the output portion via a bearing. The gear reducer according to any one of claims 1 to 7,
A cover that covers at least part of the front surface of the carrier pin and the external gear;
A rotor magnet that is disposed radially outside the input shaft and rotates with the input shaft;
An armature fixed to the lid and overlapping the rotor magnet in a radial direction;
A gear reducer further comprising: The gear reducer according to any one of claims 1 to 8,
An input shaft disposed in front of the input shaft and rotating about the rotation axis;
A speed reducer that decelerates the rotational speed of the input shaft to the input rotational speed;
A gear reducer further comprising: The gear reducer according to any one of claims 1 to 9,
A gear reducer in which the carrier and the plurality of carrier pins are a single member. The gear reducer according to any one of claims 1 to 10, wherein
The eccentric body is composed of a single member,
A gear reducer in which the eccentric bodies are respectively arranged between the plurality of external gears and the radial direction of the input shaft.

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