JP2018011393A - Geared motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a geared motor capable of obtaining a large speed reduction ratio and of being miniaturized in an axial direction.SOLUTION: A geared motor 1 comprises: a motor part 9 that comprises a stator 6 and a rotor 5 arranged at an inner peripheral side of the stator 6; a speed reduction mechanism part 8 that receives rotation of the motor part 9; and an output axis 3 to which the rotation of the motor part 9 is communicated via the speed reduction mechanism part 8. The motor part 9 comprises a magical planetary gear mechanism 7 arranged at an inner peripheral side of the rotor 5. The speed reduction mechanism part 8 comprises planetary gear mechanisms of two stages (a first planetary gear mechanism 40 and a second planetary gear mechanism 50).SELECTED DRAWING: Figure 2

Description

  The present invention relates to a geared motor incorporating a reduction mechanism that transmits rotation of a rotor to an output shaft.

  As an actuator for driving a driven member, a geared motor incorporating a speed reduction mechanism between a rotor and an output shaft is used. When the rotor diameter cannot be increased, a reduction mechanism having a large reduction ratio such as a planetary gear mechanism can be used to obtain a geared motor having a large torque. Patent Document 1 discloses a planetary gear device that decelerates the rotation of a motor and transmits it to an output shaft using a multi-stage planetary gear mechanism.

Japanese Patent No. 2014-173708

  The planetary gear device of Patent Document 1 obtains a necessary reduction ratio by overlapping a plurality of planetary gear mechanisms in the axial direction of the motor. Therefore, when the reduction ratio is increased, the axial dimension of the geared motor increases. Therefore, it is difficult to achieve both a large reduction ratio and a reduction in size of the geared motor in the axial direction.

  In view of the above problems, an object of the present invention is to propose a geared motor that can obtain a large reduction ratio and can be reduced in the axial direction.

  In order to solve the above-described problems, a geared motor according to the present invention includes a motor unit including a stator and a rotor disposed on an inner peripheral side of the stator, and a speed reduction mechanism unit to which rotation of the motor unit is input. An output shaft through which the rotation of the motor unit is transmitted via the reduction mechanism unit, and the motor unit includes a mysterious planetary gear mechanism disposed on the inner peripheral side of the rotor, and the reduction mechanism The section includes at least one planetary gear mechanism.

  According to the present invention, the mysterious planetary gear mechanism having a larger reduction ratio than the planetary gear mechanism is provided in the preceding stage of the speed reduction mechanism unit using the planetary gear mechanism, and this mysterious planetary gear mechanism is incorporated on the inner peripheral side of the rotor. . Therefore, a large reduction ratio can be obtained without increasing the axial dimension of the geared motor.

  In the present invention, it is preferable that the motor unit, the speed reduction mechanism unit, and the output shaft are arranged coaxially. In this way, the rotor, stator, and mysterious planetary gear mechanism can be dropped coaxially into the case, and then the geared motor can be assembled by dropping the parts of the reduction mechanism and the output shaft coaxially with the motor portion. Therefore, the assembly work of the geared motor is easy.

In the present invention, the motor section, the speed reduction mechanism section, and a shaft body that passes through the center of the output shaft are provided, and the rotor, the speed reduction mechanism section, and the output shaft rotate on the outer peripheral surface of the shaft body. Is desirable. If it does in this way, since it becomes a structure which assembles each part of a geared motor on the basis of the same shaft object, transmission of rotation from a motor part to an output shaft can be performed efficiently.

  In the present invention, the motor unit includes an output member that rotates integrally with an output element of the mysterious planetary gear mechanism, and the speed reduction mechanism unit includes a sun gear that is an input element of the planetary gear mechanism, and the output member The sun gear preferably uses the outer peripheral surface of the shaft body as a reference for rotation. If it does in this way, since it becomes the structure which assembles | attaches the output member of a motor part, and the sun gear of a reduction mechanism part on the basis of the same shaft body, the shift | offset | difference of the center of an output member and a sun gear can be suppressed. Therefore, it is possible to efficiently transmit rotation from the motor unit to the speed reduction mechanism unit.

  In the present invention, the sun gear preferably rotates integrally with the output member. If it does in this way, since the output stage of a motor part and the input stage of a speed-reduction mechanism part are comprised by the member which rotates integrally, the transmission of rotation from a motor part to the speed-reduction mechanism part can be performed efficiently.

  In the present invention, it is preferable that the planetary gear mechanism includes a planetary carrier, and the planetary carrier is positioned in the axial direction of the output shaft via a rib formed on the planetary carrier. If it does in this way, the assembly accuracy of a speed-reduction mechanism part can be raised.

  In the present invention, it is desirable that the speed reduction mechanism unit includes a torque limiter. If it does in this way, transmission of the unintended external force input from an output shaft can be interrupted | blocked by the deceleration mechanism part. Therefore, damage to the geared motor can be avoided.

  In the present invention, it is desirable that the speed reduction mechanism section includes a planetary gear mechanism that overlaps a plurality of stages between the motor section and the output shaft. If it does in this way, it can avoid that the size of a geared motor increases in the direction which intersects the direction of an axis of a motor part and an output shaft.

  In the present invention, it is desirable that the torque limiter is provided in an input stage planetary gear mechanism in the reduction mechanism. In this way, since the torque limiter is provided at the position where the torque is the smallest in the speed reduction mechanism, the limit torque value of the torque limiter can be set small. Therefore, the torque limiter can be reduced in size, and the geared motor can be reduced in the radial direction.

  In the present invention, it is desirable that the torque limiter is provided in a last stage planetary gear mechanism in the speed reduction mechanism section. In this case, since the torque limiter is provided at a position close to the output shaft in the speed reduction mechanism portion, there are few parts interposed between the output shaft and the torque limiter. Therefore, there are few operational variations and malfunctions due to component dimensional errors.

  In the present invention, the friction mechanism includes a case in which the motor unit and the speed reduction mechanism unit are accommodated, and the torque limiter generates a preset frictional force between the fixed element of the planetary gear mechanism and the case. It is desirable that Since such a friction mechanism has a simple structure, it can be made compact. Therefore, an increase in the size of the geared motor due to the incorporation of the torque limiter can be suppressed.

  In the present invention, each of the plurality of stages of planetary gear mechanisms preferably includes separate fixing members, the fixing members include internal gears, and are assembled to the inner peripheral side of the case. In this way, when the torque limiter is incorporated in the speed reduction mechanism, the friction mechanism can be provided at a desired position from the input stage to the final stage.

In the present invention, the friction mechanism includes a wire spring disposed between an outer cylindrical portion constituting an outer peripheral surface of the fixing member and an inner cylindrical portion on which the internal gear is formed, and the wire spring is It is desirable to urge the outer cylindrical portion toward the outer peripheral side. Such a friction mechanism is small and easy to assemble.

  In the present invention, it is preferable that the outer cylindrical portion includes at least one slit that divides the outer cylindrical portion in the circumferential direction. If it does in this way, an outer cylindrical part can be expanded in diameter with the urging | biasing force of a wire spring, and a frictional force can be generated.

  In the present invention, it is preferable that the fixing member includes an annular plate portion connected to an end portion in the axial direction of the outer cylindrical portion, and the slit extends to an outer peripheral edge of the annular plate portion. If it does in this way, since the urging | biasing force of the wire spring for expanding an outer cylindrical part diameter can be made small, a wire spring can be reduced in size.

  In the present invention, it is desirable that the outer cylindrical portion includes a claw portion protruding toward the inner peripheral side. If it does in this way, since a wire spring can be hold | maintained between a nail | claw part and an annular plate part, it can prevent that a wire spring remove | deviates from a fixing member.

  The case includes a first case disposed on one side in the axial direction of the output shaft and a second case disposed on the other side, and the first case is an end that rotatably supports the output shaft. A plate portion and a cylindrical portion extending from the end plate portion to the second case side, wherein the speed reduction mechanism portion and the motor portion are relative to the first case with respect to an inner peripheral surface of the cylindrical portion. It is desirable to be positioned. If it does in this way, a motor part and a speed-reduction mechanism part can be assembled | attached coaxially on the basis of the internal peripheral surface of a 1st case, Furthermore, an output shaft supported rotatably by a 1st case is a motor part and a speed-reduction mechanism part. And can be assembled coaxially.

  According to the present invention, the mysterious planetary gear mechanism having a larger reduction ratio than the planetary gear mechanism is provided in the preceding stage of the speed reduction mechanism unit using the planetary gear mechanism, and this mysterious planetary gear mechanism is incorporated on the inner peripheral side of the rotor. . Therefore, a large reduction ratio can be obtained without increasing the axial dimension of the geared motor.

It is a disassembled perspective view of the geared motor to which this invention is applied. It is sectional drawing of the geared motor to which this invention is applied. It is the disassembled perspective view which looked at the speed-reduction mechanism part and the mysterious planetary gear mechanism from the output-shaft side. It is the disassembled perspective view which looked at the speed-reduction mechanism part and the mysterious planetary gear mechanism from the motor part side.

  Embodiments of a geared motor to which the present invention is applied will be described below with reference to the drawings.

(overall structure)
FIG. 1 is a perspective view of a geared motor 1 to which the present invention is applied, and FIG. 2 is a sectional view of the geared motor 1 to which the present invention is applied. The geared motor 1 includes a substantially cylindrical case 2 as a whole and an output shaft 3 protruding from the center of one end face of the case 2. The output shaft 3 is arranged coaxially with the case 2. In the present specification, of one side and the other side of the output shaft 3 in the axial direction L, a direction in which the output shaft 3 protrudes from the case 2 is defined as a first direction L1, and a direction opposite to the first direction L1 is defined as a second direction. Let L2.

  The case 2 includes a first case 21 from which the output shaft 3 protrudes, and a second case 22 positioned on the second direction L2 side with respect to the first case 21. The first case 21 includes a circular end plate portion 211 and a cylindrical portion 212 connected to the outer peripheral edge of the end plate portion 211. The cylindrical portion 212 extends from the end plate portion 211 in the second direction L2. A circular opening 213 is formed in the center of the end plate portion 211. The second case 22 includes an end plate portion 221 that faces the end plate portion 211 of the first case 21 in the axial direction L, and a cylindrical portion 222 that is connected to the outer peripheral edge of the end plate portion 221. The cylindrical portion 222 extends from the end plate portion 221 in the first direction L1. As shown in FIG. 2, the first case 21 and the second case 22 are assembled coaxially. When the first case 21 and the second case 22 are assembled, the tip end portion of the cylindrical portion 222 of the second case 22 is fitted to the inner peripheral side of the cylindrical portion 212 of the first case 21.

  The geared motor 1 includes a shaft body 4 disposed coaxially with the output shaft 3 in the case 2, a rotor 5 disposed coaxially with the shaft body 4, and the shaft body 4 and the rotor 5 coaxially on the outer peripheral side of the rotor 5. , The strange planetary gear mechanism 7 arranged on the inner peripheral side of the rotor 5, and the speed reduction mechanism located on the first direction L1 side with respect to the rotor 5, the stator 6, and the strange planetary gear mechanism 7. Part 8 is provided. The mysterious planetary gear mechanism 7 and the speed reduction mechanism unit 8 are configured coaxially with the shaft body 4 as a whole.

  The rotor 5, the stator 6, and the mysterious planetary gear mechanism 7 constitute a motor unit 9 in which the mysterious planetary gear mechanism 7 is incorporated on the inner peripheral side of the rotor 5. The motor unit 9, the speed reduction mechanism unit 8, and the output shaft 3 are arranged so as to overlap with the axial direction L in this order. In the geared motor 1, a shaft body 4 is disposed so as to pass through the center of the motor section 9, the speed reduction mechanism section 8, and the output shaft 3, and the outer peripheral surface of the shaft body 4 is the rotor 5, the speed reduction mechanism section 8, and the output shaft. 3 is a reference for rotation.

  The motor unit 9 decelerates and outputs the rotation of the rotor 5 by the mysterious planetary gear mechanism 7. The output rotation of the motor unit 9 is input to the speed reduction mechanism unit 8. A planetary carrier 53 that is an output member of the speed reduction mechanism portion 8 is provided at an end portion of the speed reduction mechanism portion 8 in the first direction L1. The output shaft 3 rotates integrally with the planet carrier 53. In this embodiment, the output shaft 3 is formed integrally with the planet carrier 53, but a structure in which the output shaft 3, which is separate from the planet carrier 53, is fixed to the planet carrier 53 may be used. The deceleration mechanism unit 8 decelerates the rotation of the motor unit 9 and transmits it to the output shaft 3.

  An end portion of the shaft body 4 in the second direction L2 is press-fitted into a concave portion 223 formed at the center of the end plate portion 221 of the second case 22. On the other hand, the end of the shaft body 4 in the first direction L <b> 1 is assembled to the planetary carrier 53 that is an output member of the speed reduction mechanism 8 and the shaft hole 31 formed at the center of the output shaft 3. Accordingly, the output shaft 3 rotates with respect to the outer peripheral surface of the shaft body 4.

(Motor part)
The stator 6 includes an A-phase stator set 10 </ b> A and a B-phase stator set 10 </ b> B that are arranged to overlap in the axial direction L. The A-phase stator assembly 10A includes a bobbin 11A, an A-phase coil 12A wound around the bobbin 11A, an outer stator core 13A disposed in the first direction L1 of the bobbin 11A, and a second direction L2 of the bobbin 11A. An inner stator core 14A is provided. The bobbin 11A and the coil 12A are accommodated between the outer stator core 13A and the inner stator core 14A. The B-phase stator assembly 10B has a configuration in which the A-phase stator assembly 10A is reversed in the axial direction L. The bobbin 11B, the B-phase coil 12B wound around the bobbin 11B, and the bobbin 11B An inner stator core 14B disposed in the first direction L1 and an outer stator core 13B disposed in the second direction L2 of the bobbin 11B are provided. The bobbin 11B and the coil 12B are accommodated between the outer stator core 13B and the inner stator core 14B.

The A-phase stator set 10A and the B-phase stator set 10B constitute an integral stator 6 as a whole by joining the inner stator cores 14A and 14B. Bobbin 11A, 1
1B is provided with a terminal block 15, and the outer stator cores 13 </ b> A and 13 </ b> B are provided with a cover 16 that covers the terminal block 15. The terminal block 15 and the cover 16 protrude outside the case 2 from a notch 224 formed in the cylindrical portion 222 of the second case 22.

  The rotor 5 includes a cylindrical portion 17 disposed on the inner peripheral side of the stator 6 and a magnet 18 fixed to the outer peripheral surface of the cylindrical portion 17. The magnet 18 is magnetized so that S poles and N poles are alternately arranged in the circumferential direction. The outer peripheral surface of the magnet 18 faces the pole teeth formed on the inner peripheral surfaces of the A-phase stator assembly 10A and the B-phase stator assembly 10B with a gap therebetween.

(Wonder planetary gear mechanism)
3 is an exploded perspective view of the speed reduction mechanism unit 8 and the strange planetary gear mechanism 7 as viewed from the output shaft 3 side, and FIG. 4 is a view of the speed reduction mechanism unit 8 and the strange planetary gear mechanism 7 from the motor unit 9 side. It is a disassembled perspective view. The strange planetary gear mechanism 7 includes a planetary carrier 71 that rotates integrally with the rotor 5 on the inner peripheral side of the rotor 5, two planetary gears 72 that are rotatably held by the planetary carrier 71, and a second planetary carrier 71. An internal gear 73 that meshes with the two planetary gears 72 on the direction L2 side and an internal gear 74 that meshes with the two planetary gears 72 on the first direction L1 side of the planet carrier 71 are provided. The planet carrier 71, the internal gear 73, and the internal gear 74 are arranged coaxially with the shaft body 4. Further, the two planetary gears 72 are arranged at an angular position that is 180 ° apart from the shaft body 4.

  The planet carrier 71 includes two support shafts 711 passing through the center of the planetary gear 72 and a planetary gear holding portion 712 in which holding holes for holding the planetary gear 72 are formed in two places. Since the outer peripheral portion of the planetary gear holding portion 712 is connected to the inner peripheral surface of the rotor 5, the planet carrier 71 rotates integrally with the rotor 5. The rotor 5 and the planet carrier 71 are rotatably supported by the shaft body 4 assembled at the center of the planetary gear holder 712. Accordingly, the rotor 5 and the planet carrier 71 rotate with reference to the outer peripheral surface of the shaft body 4.

  The internal gear 73 is formed on the inner peripheral surface of the cylindrical portion 225 that protrudes from the end plate portion 221 of the second case 22 in the first direction L1 on the inner peripheral side of the rotor 5. An annular recess 226 is formed on the end plate portion 221 on the outer peripheral side of the cylindrical portion 225. An end of the rotor 5 in the second direction L2 is disposed in the annular recess 226.

  The internal gear 74 is formed on the output member 75 arranged on the planetary carrier 71 on the first direction L1 side. The output member 75 is a cup-shaped member including a cylindrical portion 751 having an internal gear 74 formed on the inner peripheral surface and an end plate portion 752 that closes an end portion of the cylindrical portion 751 in the first direction L1. The output member 75 rotates integrally with the sun gear 41 that is a gear of the input stage of the speed reduction mechanism unit 8. The sun gear 41 is fixed or integrally formed on the surface of the end plate portion 752 in the first direction L1. The output member 75 and the sun gear 41 are rotatably supported by the shaft body 4 assembled at the center of the end plate portion 752 and the sun gear 41. Therefore, the output member 75 and the sun gear 41 rotate with reference to the outer peripheral surface of the shaft body 4.

  The internal gear 73 is a fixed element of the mysterious planetary gear mechanism 7, the planet carrier 71 is an input element of the mysterious planetary gear mechanism 7, and the internal gear 74 is an output element of the mysterious planetary gear mechanism 7. As described above, since the internal gear 74 is formed in the cylindrical portion 751 of the output member 75, the output element of the mysterious planetary gear mechanism 7 rotates integrally with the output member 75 of the motor portion 9. When the rotor 5 rotates, the planet carrier 71 rotates together with the rotor 5, so that the planetary gear 72 meshing with the internal gear 73 revolves around the shaft body 4 while rotating. Since the number of teeth of the internal gear 73 is larger than the number of teeth of the internal gear 74, the output member 75 formed with the internal gear 74 has the number of teeth of the internal gear 73 and the number of teeth of the internal gear 74. It is decelerated at a reduction ratio corresponding to the difference and rotates.

(Deceleration mechanism)
The speed reduction mechanism unit 8 includes a first planetary gear mechanism 40 and a second planetary gear mechanism 50. The first planetary gear mechanism 40 and the second planetary gear mechanism 50 are speed reduction mechanisms, and are arranged in this order so as to overlap the first direction L1. The first planetary gear mechanism 40 is a reduction mechanism at the input stage of the reduction mechanism unit 8 and is disposed so as to overlap the first direction L1 side of the motor unit 9. As described above, since the mysterious planetary gear mechanism 7 is incorporated in the central portion of the motor unit 9, when the speed reduction mechanism unit 8 is arranged on the first direction L1 side of the motor unit 9, the mysterious planetary gear mechanism 7, In the order of the first planetary gear mechanism 40 and the second planetary gear mechanism 50, the reduction mechanisms are arranged in three stages. The output rotation of the mysterious planetary gear mechanism 7 is transmitted to the first planetary gear mechanism 40. The second planetary gear mechanism 50 is the final stage reduction mechanism of the reduction mechanism unit 8, and reduces the output rotation of the first planetary gear mechanism 40 and transmits it to the output shaft 3.

(First planetary gear mechanism 40)
The first planetary gear mechanism 40 includes a sun gear 41 that rotates integrally with the output member 75 of the mysterious planetary gear mechanism 7, three metal planetary gears 42 that mesh with the sun gear 41, and three planetary gears 42. A planet carrier 43 to be held and an internal gear 44 that meshes with the three planet gears 42 are provided. The sun gear 41, the planet carrier 43, and the internal gear 44 are arranged coaxially with the shaft body 4. The three planetary gears 42 are arranged at equiangular intervals around the shaft body 4.

  The planetary carrier 43 includes a disc portion 431 disposed coaxially with the output shaft 3, an annular plate portion 432 positioned at a predetermined distance on the second direction L 2 side of the disc portion 431, and a first from the annular plate portion 432. Three support shafts 433 projecting in the direction L1 are provided. The three support shafts 433 are arranged at equiangular intervals in the circumferential direction. The tips of the three support shafts 433 are respectively fitted with three convex portions 434 protruding from the disc portion 431 in the second direction L2. A planetary gear 42 is rotatably attached to each of the three support shafts 433.

  The planet carrier 43 rotates integrally with a sun gear 51 that is an input stage gear of the second planetary gear mechanism 50. The sun gear 51 protrudes from the disc portion 431 in the first direction L1, and is fixed or integrally formed with the disc portion 431. The planetary carrier 43 is formed with a shaft hole 435 that passes through the centers of the sun gear 51 and the disk portion 431. In the shaft hole 435, a circular convex portion 536 provided on the planet carrier 53 which is an output element of the second planetary gear mechanism 50 is disposed. The planetary carrier 43 and the sun gear 51 are supported so as to be rotatable about the shaft body 4 assembled in the shaft hole 31 passing through the center of the planetary carrier 53 via the circular convex portion 536. That is, the planet carrier 43 and the sun gear 51 rotate with respect to the outer peripheral surface of the shaft body 4.

  The first planetary gear mechanism 40 includes a fixing member 45 that surrounds the outer peripheral side of the planet carrier 43 and the second direction L2 side. The fixing member 45 includes an inner cylindrical portion 451 and an outer cylindrical portion 452 that are arranged coaxially with the shaft body 4 on the outer peripheral side of the planetary carrier 43, and end portions in the axial direction L of the inner cylindrical portion 451 and the outer cylindrical portion 452 (that is, , An annular plate portion 453 connected to the end portion in the second direction L2. The internal gear 44 is formed on the inner peripheral surface of the inner cylindrical portion 451.

  The sun gear 41 is an input element of the first planetary gear mechanism 40, the internal gear 44 is a fixed element of the first planetary gear mechanism 40, and the planet carrier 43 is an output element of the first planetary gear mechanism 40. When the output member 75 of the mysterious planetary gear mechanism 7 provided at the front stage of the first planetary gear mechanism 40 rotates, the sun gear 41 rotates integrally with the output member 75. As a result, the planetary gear 42 meshing with the sun gear 41 revolves around the shaft body 4 while rotating. Then, as the planetary gear 42 revolves, the planetary carrier 43 rotates around the shaft body 4. The planet carrier 43 is decelerated at a reduction ratio corresponding to the number of teeth of the sun gear 41 and the number of teeth of the internal gear 44 and rotates.

(Second planetary gear mechanism 50)
The second planetary gear mechanism 50 includes a sun gear 51 that rotates integrally with the planet carrier 43 of the first planetary gear mechanism 40, three metal planetary gears 52 that mesh with the sun gear 51, and three planetary gears 52. And an internal gear 54 that meshes with the three planetary gears 52. The sun gear 51, the planet carrier 53, and the internal gear 54 are arranged coaxially with the shaft body 4. The three planetary gears 52 are arranged at equiangular intervals around the shaft body 4.

  The planetary carrier 53 includes a disc portion 531 arranged coaxially with the shaft body 4, an annular plate portion 532 located at a predetermined distance on the second direction L 2 side of the disc portion 531, and a first from the annular plate portion 532. Three support shafts 533 projecting in the direction L1 are provided. The tips of the three support shafts 533 are fitted with three convex portions 534 that protrude from the disc portion 531 in the second direction L2. The three support shafts 533 are arranged at equiangular intervals in the circumferential direction. A planetary gear 52 is rotatably attached to each of the three support shafts 533.

  As described above, the output shaft 3 is formed integrally with the planetary carrier 53. The planet carrier 53 includes a circular convex portion 535 that protrudes from the center of the disk portion 531 in the first direction L1, and the output shaft 3 protrudes from the center of the circular convex portion 535 in the first direction L1. Further, the planet carrier 53 includes a circular convex portion 536 that protrudes from the center of the disc portion 531 in the second direction L2. As described above, the circular convex portion 536 is assembled to the shaft hole 435 of the planet carrier 43 that is a constituent member of the first planetary gear mechanism 40. The planetary carrier 53 is formed with a circular convex portion 536, a disc portion 531, and a shaft hole 31 passing through the center of the output shaft 3, and an end portion of the shaft body 4 in the first direction L <b> 1 is inserted into the shaft hole 31. .

  The internal gear 54 is formed on the inner peripheral surface of a cylindrical member 55 disposed on the outer peripheral side of the planet carrier 53. The sun gear 51 is an input element of the second planetary gear mechanism 50, the internal gear 54 is a fixed element of the second planetary gear mechanism 50, and the planet carrier 53 is an output element of the second planetary gear mechanism 50. When the planet carrier 43 that is the output element of the first planetary gear mechanism 40 provided at the front stage of the second planetary gear mechanism 50 rotates, the sun gear 51 rotates together with the planet carrier 43. As a result, the planetary gear 52 that meshes with the sun gear 51 revolves around the shaft body 4 while rotating. As the planetary gear 52 revolves, the planetary carrier 53 rotates about the shaft body 4. The planetary carrier 53 rotates at a reduced speed corresponding to the number of teeth of the sun gear 51 and the number of teeth of the internal gear 54. The output shaft 3 rotates integrally with the planet carrier 53.

(Positioning of deceleration mechanism 8 in the axial direction L)
The fixing member 45 that is a fixing element of the first planetary gear mechanism 40 is assembled such that the annular plate portion 453 contacts the stator 6 in the second direction L2. The planet carrier 43 holding the planetary gear 42 is assembled so that the annular plate portion 432 contacts the annular plate portion 453 of the fixing member 45.

  The cylindrical member 55 that is a fixing element of the second planetary gear mechanism 50 is assembled so as to contact the fixing member 45 of the first planetary gear mechanism 40 in the second direction L2. Further, the annular plate portion 532 of the planet carrier 53 holding the planetary gear 52 abuts on the disc portion 431 of the planet carrier 43 in the second direction L2. That is, the first planetary gear mechanism 40 is positioned in the axial direction L when the fixing member 45 contacts the stator 6 in the axial direction L. Further, the planet carrier 43 is positioned in the axial direction L by being sandwiched between the fixing member 45 and the planet carrier 53 in the axial direction L.

  The planet carrier 43 is formed with a rib 437 extending in an annular shape around the shaft body 4 on the surface of the disc portion 431 in the first direction L1. The rib 437 has a curved cross-sectional shape when cut in the radial direction. The disk part 531 of the planet carrier 53 abuts on the disk part 431 of the planet carrier 43 at the apex of the rib 437. That is, the position of the planet carrier 43 in the axial direction L is determined by the rib 437 and the disk portion 531 coming into contact with each other.

  The speed reduction mechanism unit 8 is disposed in a space between the motor unit 9 accommodated in the second case 22 and the first case 21. When the first case 21 is put on the speed reduction mechanism portion 8, the circular convex portion 535 of the planetary carrier 53 is fitted into the circular opening 213 formed in the end plate portion 211. Then, the end plate portion 211 of the first case 21 contacts the cylindrical member 55 of the second planetary gear mechanism 50, and the end plate portion 211 contacts the disc portion 531 of the planet carrier 53. That is, the second planetary gear mechanism 50 is positioned in the axial direction L when the cylindrical member 55 is sandwiched in the axial direction L by the end plate portion 211 of the first case 21 and the fixing member 45 of the first planetary gear mechanism 40. . Further, the planet carrier 53 is positioned in the axial direction L by being sandwiched between the end plate portion 211 of the first case 21 and the planet carrier 43 in the axial direction L. In this way, the speed reduction mechanism unit 8 is sandwiched between the motor unit 9 and the end plate portion 211 of the first case 21 and positioned in the axial direction L. Further, the outer peripheral side of the speed reduction mechanism unit 8 is covered by the cylindrical portion 212 of the first case 21.

  The planetary carrier 53 is formed with a rib 537 extending in an annular shape around the shaft body 4 on the surface of the disc portion 531 in the first direction L1. The rib 537 has a curved cross-sectional shape when cut in the radial direction. The disc portion 531 comes into contact with the end plate portion 211 at the apex of the rib 537. That is, the position of the planet carrier 53 in the axial direction L is determined by the rib 537 and the end plate portion 211 coming into contact with each other. By positioning in the axial direction L using the annular rib, the planetary carriers 43 and 53 are suppressed from being inclined with respect to the axial direction L.

(Torque limiter)
A torque limiter 60 is incorporated in the first planetary gear mechanism 40 which is the planetary gear mechanism at the input stage of the speed reduction mechanism unit 8. In this embodiment, a friction mechanism 60 </ b> A is used as the torque limiter 60. The speed reduction mechanism unit 8 of this embodiment includes a fixing member 45 including an internal gear 44 that is a fixing element of the first planetary gear mechanism 40 and a cylindrical member including an internal gear 54 that is a fixing element of the second planetary gear mechanism 50. 55 are constituted by separate members. These members are separated from the first case 21 and assembled to the inner peripheral side of the first case 21. With this configuration, a friction mechanism can be provided between the first case 21 and the first planetary gear mechanism 40 or between the first case 21 and the second planetary gear mechanism 50.

  The friction mechanism 60 </ b> A includes an outer cylindrical portion 452 of the fixing member 45 and a wire spring 47 disposed in an annular groove portion 46 provided between the outer cylindrical portion 452 and the inner cylindrical portion 451. In the outer cylindrical portion 452, slits 48 are formed at four positions at equal angular intervals in the circumferential direction. The outer cylindrical portion 452 is divided into four in the circumferential direction by these slits 48. The slit 48 extends from the edge of the outer cylindrical portion 452 in the first direction L1 to the outer peripheral edge of the annular plate portion 453.

  On the inner peripheral surface of the end edge of the outer cylindrical portion 452 in the first direction L1, a claw portion 49 protruding to the inner peripheral side is formed. The opening of the groove portion 46 faces the first direction L1, and the claw portion 49 closes the outer peripheral portion of the opening. Further, the inner peripheral side portion of the opening of the groove portion 46 is closed by a cylindrical member 55 that contacts the end surface of the inner cylindrical portion 451 on the first direction L1 side. The claw portion 49 and the cylindrical member 55 function as a retaining member that prevents the wire spring 47 from coming off from the groove portion 46 in the first direction L1. The wire spring 47 is held between the claw portion 49 and the fixing member 45 and the annular plate portion 453. In this embodiment, the claw portion 49 is formed over the entire circumference, but the claw portion 49 may be provided only in a part of the circumferential direction.

The wire spring 47 is a single annular coil spring and biases the outer cylindrical portion 452 toward the outer peripheral side. The above-described slit 48 is formed in the outer cylindrical portion 452, and the slit 48 has a shape cut into the inner peripheral side at the outer peripheral edge of the annular plate portion 453. By providing such a slit 48, the outer cylindrical portion 45 is urged by the urging force of the wire spring 47.
2 falls to the outer peripheral side, and the end portion in the first direction L1 of the outer cylindrical portion 452 expands to the outer peripheral side. The friction mechanism 60 </ b> A expands the outer cylindrical portion 452 by the urging force of the wire spring 47, and generates a frictional force by pressing the outer peripheral surface of the outer cylindrical portion 452 against the inner peripheral surface of the cylindrical portion 212 of the first case 21. . The urging force of the wire spring 47 is set so as to generate a preset static frictional force between the inner peripheral surface of the cylindrical portion 212 and the outer peripheral surface of the outer cylindrical portion 452.

  That is, in the friction mechanism 60 </ b> A, the internal gear 44 having a torque larger than the static friction force acting between the inner peripheral surface of the cylindrical portion 212 and the outer peripheral surface of the outer cylindrical portion 452 is a fixed element of the first planetary gear mechanism 40. When fixed, the fixing member 45 on which the internal gear 44 is formed is configured to idle with respect to the cylindrical portion 212. The maximum torque at which the fixing member 45 does not idle is the limit torque value of the friction mechanism 60A.

  When an unintended external force is input to the output shaft 3 of the geared motor 1, the torque input from the output shaft 3 to the second planetary gear mechanism 50 at the final stage of the speed reduction mechanism unit 8 causes the planetary carrier 53 and the planetary gear 52 to enter. Is transmitted to the sun gear 51 and the planetary carrier 43 through the first planetary gear mechanism 40, and torque is transmitted to the sun gear 41 or the internal gear 44 through the planetary carrier 43 and the planetary gear 42.

  Here, the sun gear 41 is formed integrally with the output member 75 of the mysterious planetary gear mechanism 7. Since the mysterious planetary gear mechanism 7 cannot be rotated by applying a force to the output element, the sun gear 41 cannot be rotated by the torque transmitted from the output shaft 3 side. Accordingly, torque is transmitted to the fixing member 45 via the internal gear 44. When the torque transmitted from the output shaft 3 side is larger than the limit torque value of the friction mechanism 60 </ b> A, the fixing member 45 idles with respect to the cylindrical portion 212.

(Function and effect)
As described above, the geared motor 1 according to this embodiment includes the motor unit 9 including the stator 6 and the rotor 5 disposed on the inner peripheral side of the stator 6, and the speed reduction mechanism unit to which the rotation of the motor unit 9 is input. 8 and an output shaft 3 to which the rotation of the motor unit 9 is transmitted via the speed reduction mechanism unit 8. The motor unit 9 includes a mysterious planetary gear mechanism 7 disposed on the inner peripheral side of the rotor 5. The speed reduction mechanism unit 8 includes a two-stage planetary gear mechanism (a first planetary gear mechanism 40 and a second planetary gear mechanism 50). As described above, in this embodiment, the mysterious planetary gear mechanism 7 having a larger reduction ratio than the planetary gear mechanism is provided in the preceding stage of the speed reduction mechanism unit 8 using the planetary gear mechanism, and the mysterious planetary gear mechanism 7 is disposed on the inner periphery of the rotor 5. It is built into the side. Therefore, a large reduction ratio can be obtained without increasing the dimension of the geared motor 1 in the axial direction L.

  The speed reduction mechanism unit 8 of this embodiment includes a planetary gear mechanism that is stacked in a plurality of stages between the motor unit 9 and the output shaft 3. In this way, it is possible to avoid an increase in the size of the geared motor 1 in a direction that intersects the axial direction L of the output shaft 3.

  The speed reduction mechanism unit 8 of this embodiment includes a torque limiter 60. Therefore, transmission of an unintended external force input from the output shaft 3 can be blocked by the speed reduction mechanism unit 8. Therefore, damage to the geared motor 1 can be avoided. In the present embodiment, as a torque limiter, a preset friction force is generated between the fixing member 45 that is a fixing element of the first planetary gear mechanism 40 included in the speed reduction mechanism portion 8 and the cylindrical portion 212 of the first case 21. A friction mechanism 60A is used. Since such a friction mechanism 60A has a simple structure, it can be made compact. Therefore, an increase in the size of the geared motor 1 due to the incorporation of the torque limiter 60 can be suppressed.

In this embodiment, the outer cylindrical portion 452 is provided on the outer peripheral side of the internal gear 44 of the first planetary gear mechanism 40, and the friction mechanism is formed by pressing the outer cylindrical portion 452 against the inner peripheral surface of the first case 21 by the wire spring 47. 60A is configured. As described above, the simple structure in which the inner peripheral surface of the first case 21 is used as a friction surface and the outer cylindrical portion 452 and the wire spring 47 are provided on the inner peripheral side of the first case 21 is small and assembled. Is easy. Further, the outer cylindrical portion 452 can be enlarged in diameter by providing the slit 48 in the outer cylindrical portion 452, and in particular, since the slit 48 extends to the outer peripheral edge of the annular plate portion 453, the outer cylindrical portion 452 is small. Easily expands diameter with urging force. Therefore, it is possible to generate a necessary frictional force with the small wire spring 47.

  In this embodiment, the friction mechanism 60 </ b> A as the torque limiter 60 is provided in the input stage planetary gear mechanism (first planetary gear mechanism 40) in the speed reduction mechanism unit 8. By doing so, the rotation speed is increased and the torque is reduced when the speed reduction mechanism 8 is transmitted from the final stage to the input stage, so that the friction mechanism 60A is provided at a position where the torque is the smallest in the speed reduction mechanism 8. It will be. Therefore, the limit torque value of the friction mechanism 60A (torque limiter 60) can be set small. Therefore, the friction mechanism 60A (torque limiter 60) can be reduced in size, and the geared motor 1 can be reduced in the radial direction.

  In this embodiment, each of the multi-stage planetary gear mechanisms (first planetary gear mechanism 40, second planetary gear mechanism 50) includes fixing members (fixing member 45, cylindrical member 55) that are separate from each other. The member is assembled on the inner peripheral side of the first case 21. Thus, since each of the plurality of stages of planetary gear mechanisms includes a fixing member as an independent member, any one of the plurality of stages is used by utilizing one of these fixing members. It is possible to configure a friction mechanism in the gear mechanism.

  In this embodiment, the motor unit 9, the speed reduction mechanism unit 8, and the output shaft 3 are arranged coaxially. Therefore, the components of the rotor 5, the stator 6, and the strange planetary gear mechanism 7 are dropped coaxially with the shaft body 4 into the first case 21 in which the shaft body 4 is assembled, and then the components of the speed reduction mechanism section 8 and the output shaft 3 Can be assembled coaxially. Therefore, the assembly work of the geared motor 1 is easy.

  In this embodiment, the motor unit 9, the speed reduction mechanism unit 8, and the shaft body 4 that passes through the center of the output shaft 3 are provided. The rotor 5, the speed reduction mechanism unit 8, and the output shaft 3 rotate on the outer peripheral surface of the shaft body 4. The standard. The motor unit 9 includes an output member 75 that rotates integrally with the output element of the mysterious planetary gear mechanism 7, and the speed reduction mechanism unit 8 includes a sun gear 41 that is an input element of the first planetary gear mechanism 40, The member 75 and the sun gear 41 rotate integrally with the outer peripheral surface of the shaft body 4 as a reference for rotation. Thus, since this form is a structure which attaches each part of the geared motor 1 on the basis of the same shaft body 4, and rotates it on the basis of the outer peripheral surface of the same shaft body 4, it can suppress an axial shift, and a motor part Transmission of rotation from 9 to the speed reduction mechanism unit 8 can be performed efficiently.

  In this embodiment, the planetary carriers 43 and 53 are positioned in the axial direction L through the annular ribs 437 and 537 formed on the surfaces of the planetary carriers 43 and 53 facing the first direction L1. Therefore, the assembling accuracy of the speed reduction mechanism 8 is high.

In this embodiment, the case 2 of the geared motor 1 includes a first case 21 disposed on one side in the axial direction L of the output shaft 3 and a second case 22 disposed on the other side. 21 includes an end plate portion 211 formed with an opening 213 from which the output shaft 3 projects, and a cylindrical portion 212 extending from the end plate portion 211 toward the second case 22. The output shaft 3 is fitted in the opening 213 of the end plate portion 211 and positioned in the radial direction. Further, the speed reduction mechanism portion 8 is positioned in the radial direction with the friction mechanism 60 </ b> A contacting the inner peripheral surface of the cylindrical portion 212 as a reference. Further, the second case 22 that accommodates the motor unit 9 has a cylindrical portion 212.
Therefore, the motor unit 9 is positioned in the radial direction via the second case 22 with the inner peripheral surface of the cylindrical portion of the first case 21 as a reference.

  That is, in this embodiment, the output shaft 3, the speed reduction mechanism unit 8, and the motor unit 9 can be assembled coaxially with the inner peripheral side of the first case 21 as a reference. Therefore, the mechanism of the geared motor 1 is assembled by assembling the shaft body 4 and the motor unit 9 to the second case 22, dropping the speed reduction mechanism unit 8 and the output shaft 3 around the shaft body 4, and finally assembling the first case 21. The whole can be assembled coaxially with the inner peripheral surface of the first case 21 and the shaft body 4 as a reference. And the assembly | attachment of the 1st case 21 can also perform positioning of the axial direction L of the whole mechanism. Therefore, the assembling accuracy is high and the assembling work is easy.

  Here, among the constituent members of the motor unit 9, the plurality of planetary gears 72 are held by the planetary carrier 71 in a state of being arranged at equiangular intervals around the shaft body 4. The operation of assembling coaxially with the shaft body 4 is easy. Further, among the constituent members of the speed reduction mechanism unit 8, the plurality of planetary gears 42 and 52 are held by the planetary carriers 43 and 53 in a state of being arranged at equal angular intervals around the shaft body 4, respectively. As in the case of the constituent members, the work of assembling coaxially with the shaft body 4 is easy.

  In this embodiment, since the planetary gears 42 and 52 are made of metal, the first planetary gear mechanism 40 and the second planetary gear mechanism 50 can be thinned, and the reduction mechanism unit 8 can be thinned. . Therefore, the geared motor 1 can be thinned in the axial direction L.

(Modification)
(1) Although the friction mechanism 60 </ b> A as the torque limiter 60 is provided in the input stage planetary gear mechanism (first planetary gear mechanism 40) in the speed reduction mechanism unit 8 in the above embodiment, the final stage planetary in the speed reduction mechanism unit 8. A friction mechanism 60A may be provided in the gear mechanism (second planetary gear mechanism 50). In this way, since the friction mechanism 60A (torque limiter 60) is provided at a location near the output shaft 3 in the speed reduction mechanism section 8, there is no part interposed between the output shaft 3 and the friction mechanism 60A (torque limiter 60). Few. Therefore, there are few operational variations and malfunctions due to component dimensional errors. In addition, since many members are provided on the motor unit 9 side with respect to the friction mechanism 60A (torque limiter 60), many members can be protected from unintended external forces.

(2) In the above embodiment, the speed reduction mechanism unit 8 is constituted by a two-stage planetary gear mechanism. However, the planetary gear mechanism may be constituted by a one-stage or three-stage or more planetary gear mechanism.

(3) In the above embodiment, a frictional force is generated between the inner peripheral surface of the cylindrical portion 212 and the outer peripheral surface of the outer cylindrical portion 452 by the urging force of the wire spring 47 formed of one annular coil spring. The shape, number, and spring force of the biasing member can be changed as appropriate.

(4) In the above embodiment, the planetary gears 42 and 52 are made of metal, but either one or both of the planetary gear 42 and the planetary gear 52 may be made of resin.

(5) In the above embodiment, the slits 48 are formed at four equiangular intervals in the outer cylindrical portion 452, but the positions and number of the slits 48 may be different from these. For example, the slit 48 may be one place. Or you may provide the slit 48 in two places 180 degree apart.

DESCRIPTION OF SYMBOLS 1 ... Geared motor, 2 ... Case, 3 ... Output shaft, 4 ... Shaft body, 5 ... Rotor, 6 ... Stator,
7 ... Mysterious planetary gear mechanism, 8 ... Deceleration mechanism unit, 9 ... Motor unit, 10A, 10B ... Stator assembly, 11A, 11B ... Bobbin, 12A, 12B ... Coil, 13A, 13B ... Outer stator core, 14A, 14B ... Inner stator core , 15 ... Terminal block, 16 ... Cover, 17 ... Cylindrical part, 18 ... Magnet, 21 ... First case, 22 ... Second case, 31 ... Shaft hole, 40 ... First planetary gear mechanism, 41 ... Sun gear, 42 ... Planetary gear, 43 ... Planetary carrier, 44 ... Internal gear, 45 ... Fixed member, 46 ... Groove, 47 ... Wire spring, 48 ... Slit, 49 ... Claw part, 50 ... Planetary gear mechanism, 51 ... Sun gear, 52 ... Planetary gear, 53 ... Planetary carrier, 54 ... Internal gear, 55 ... Cylindrical member, 60 ... Torque limiter, 60A ... Friction mechanism, 71 ... Planetary carrier, 72 ... Planetary gear, DESCRIPTION OF SYMBOLS 3 ... Internal gear, 74 ... Internal gear, 75 ... Output member, 211 ... End plate part, 212 ... Cylindrical part, 213 ... Opening, 221 ... End plate part, 222 ... Cylindrical part, 223 ... Recessed part, 224 ... Cutting Notch portion, 225 ... cylindrical portion, 226 ... annular recess, 431 ... disc portion, 432 ... annular plate portion, 433 ... support shaft, 434 ... convex portion, 435 ... shaft hole, 437 ... rib, 451 ... inner cylindrical portion, 452 ... Outer cylindrical portion, 453 ... annular plate portion, 531 ... circular plate portion, 532 ... annular plate portion, 533 ... support shaft, 534 ... convex portion, 535 ... circular convex portion, 536 ... circular convex portion, 537 ... rib, 711 ... support shaft, 712 ... planetary gear holding portion, 751 ... cylindrical portion, 752 ... end plate portion, L ... axial direction, L1 ... first direction, L2 ... second direction

Claims (17)

A motor unit comprising a stator and a rotor disposed on the inner peripheral side of the stator;
A speed reduction mechanism section to which rotation of the motor section is input;
An output shaft to which rotation of the motor unit is transmitted via the speed reduction mechanism unit,
The motor unit includes a mysterious planetary gear mechanism disposed on the inner peripheral side of the rotor,
The gear reduction motor is characterized in that the speed reduction mechanism section includes at least one planetary gear mechanism.   The geared motor according to claim 1, wherein the motor unit, the speed reduction mechanism unit, and the output shaft are arranged coaxially. A shaft body that passes through the center of the motor unit, the speed reduction mechanism unit, and the output shaft,
The geared motor according to claim 2, wherein the rotor, the speed reduction mechanism unit, and the output shaft use an outer peripheral surface of the shaft body as a reference for rotation. The motor unit includes an output member that rotates integrally with an output element of the mysterious planetary gear mechanism,
The speed reduction mechanism includes a sun gear that is an input element of the planetary gear mechanism,
The geared motor according to claim 3, wherein the output member and the sun gear use the outer peripheral surface of the shaft body as a reference for rotation.   The geared motor according to claim 4, wherein the sun gear rotates integrally with the output member. The planetary gear mechanism comprises a planet carrier;
The geared motor according to any one of claims 1 to 5, wherein the planetary carrier is positioned in an axial direction of the output shaft via a rib formed on the planetary carrier.   The geared motor according to any one of claims 1 to 6, wherein the speed reduction mechanism unit includes a torque limiter.   The geared motor according to claim 7, wherein the speed reduction mechanism unit includes a planetary gear mechanism that overlaps a plurality of stages between the motor unit and the output shaft.   9. The geared motor according to claim 8, wherein the torque limiter is provided in an input stage planetary gear mechanism in the speed reduction mechanism unit.   The geared motor according to claim 8, wherein the torque limiter is provided in a planetary gear mechanism at a final stage in the speed reduction mechanism unit. A case in which the motor unit and the speed reduction mechanism unit are accommodated;
11. The geared according to claim 8, wherein the torque limiter is a friction mechanism that generates a preset frictional force between a fixed element of the planetary gear mechanism and the case. motor. Each of the plurality of planetary gear mechanisms includes a separate fixing member,
The geared motor according to claim 11, wherein the fixing member includes an internal gear and is assembled to an inner peripheral side of the case. The friction mechanism includes a wire spring disposed between an outer cylindrical portion constituting an outer peripheral surface of the fixing member and an inner cylindrical portion on which the internal gear is formed,
The geared motor according to claim 12, wherein the wire spring biases the outer cylindrical portion toward an outer peripheral side.   The geared motor according to claim 13, wherein the outer cylindrical portion is provided with at least one slit that divides the outer cylindrical portion in the circumferential direction. The fixing member includes an annular plate portion connected to an end portion in the axial direction of the outer cylindrical portion,
The geared motor according to claim 14, wherein the slit extends to an outer peripheral edge of the annular plate portion.   The geared motor according to any one of claims 13 to 15, wherein the outer cylindrical portion includes a claw portion protruding toward an inner peripheral side. The case includes a first case disposed on one side in the axial direction of the output shaft, and a second case disposed on the other side,
The first case includes an end plate portion from which the output shaft protrudes, and a cylindrical portion extending from the end plate portion to the second case side,
The geared according to any one of claims 11 to 16, wherein the speed reduction mechanism portion and the motor portion are positioned with respect to the first case with reference to an inner peripheral surface of the cylindrical portion. motor.

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