JP2019039472A - Driving device - Google Patents

Abstract

To provide a technology for preventing a motor output shaft and a drive output shaft from being positionally displaced.SOLUTION: A driving device comprises: a motor including a motor output shaft including a sub gear; multiple planetary gears which are meshed with the sun gear; a carrier which is attached to the multiple planetary gears and disposed in a rotatable manner with respect to the motor; and a drive output shaft which is fixed to the carrier and extends to an opposite side of the motor. The motor output shaft extends through the carrier to the drive output shaft. The carrier includes a support part which is fixed to the carrier and supports the motor output shaft in a rotatable manner. One output shaft of the drive output shaft and the motor output shaft may also be inserted into a recess which is disposed in the other output shaft of the drive output shaft and the motor output shaft, in a rotatable manner with respect to the one output shaft.SELECTED DRAWING: Figure 1

Description

  The technology disclosed in this specification relates to a driving device including a motor.

  Patent Document 1 discloses a drive device including a motor and a speed reducer. The motor is accommodated in the electric motor case. The reduction gear is accommodated in the reduction gear case. The motor output shaft is supported at the upper end by a bearing provided in the carrier of the speed reducer, and is supported at the lower end by a bearing provided in the motor case.

JP 2017-82871 A

  In the above technique, the motor output shaft is positioned with respect to the carrier via the bearing. For this reason, if the positions of the carrier and the drive output shaft connected to the carrier are shifted, the positions of the motor output shaft and the drive output shaft are shifted. In the present specification, a technique for preventing displacement between the motor output shaft and the drive output shaft is provided.

  The technology disclosed in this specification relates to a drive device. The drive device is attached to a motor including a motor output shaft having a sun gear, a plurality of planetary gears meshing with the sun gear, and the plurality of planetary gears, and is arranged to be rotatable with respect to the motor. A carrier and a drive output shaft fixed to the carrier and extending on the opposite side of the motor, the motor output shaft passing through the carrier and extending to the drive output shaft, and the drive One output shaft of the output shaft and the motor output shaft is rotatable with respect to the one output shaft in a recess disposed on the other output shaft of the drive output shaft and the motor output shaft. May be inserted.

  According to this configuration, one output shaft of the drive output shaft and the motor output shaft is inserted into the recess of the other output shaft, thereby preventing mutual displacement.

  The other output shaft may include a first bearing disposed in the recess, and the one output shaft may be inserted into the first bearing. According to this configuration, one of the drive output shaft and the motor output shaft can smoothly rotate within the recess of the other output shaft.

  The drive device further includes a casing fixed to the motor and rotatably supporting the carrier, and one or two second bearings fixed to the casing. The second bearing Each of these may support either the said drive output shaft or the said motor output shaft rotatably with respect to the said casing. In the above configuration, the drive output shaft and the motor output shaft are mutually supported by inserting one of the drive output shaft and the motor output shaft into the other recess. Thereby, the bearing installed in a casing can be decreased.

  Each of the second bearings may be fixed to the casing on the opposite side of the carrier to the motor, and may support the drive output shaft so as to be rotatable with respect to the casing. According to this configuration, the second bearing can be disposed close to a position that receives a force from the outside of the drive output shaft. Thereby, the force added to a bearing can be reduced.

  The end of the motor output shaft facing the casing on the side opposite to the drive output shaft, or the portion of the casing facing the drive output shaft and the end opposite to the end of the motor output shaft, A rotation inhibition suppressing unit that inhibits rotation inhibition of the motor output shaft may be arranged. According to this configuration, the rotation of the motor output shaft with respect to the casing is hindered without arranging a bearing between the casing and the end portion facing the casing on the side opposite to the drive output shaft of the motor output shaft. Can be suppressed.

  The drive device may further include a heat radiating portion that radiates heat generated from the coil of the motor to the outside. According to this configuration, the heat of the motor can be radiated efficiently.

The carrier may be fixed to the carrier, and may include a support portion that rotatably supports the motor output shaft. According to this configuration, the motor output shaft can be appropriately positioned with respect to the carrier.

  The support portion may include a third bearing that rotatably supports the motor output shaft with respect to the carrier. According to this configuration, the motor output shaft can be smoothly supported at the support portion.

The longitudinal cross-sectional view of the drive device of 1st Example is shown. The longitudinal cross-sectional view of the drive device of 2nd Example is shown. The longitudinal cross-sectional view of the drive device of a modification is shown.

(First embodiment)
With reference to FIG. 1, the drive apparatus 10 of a present Example is demonstrated. The driving device 10 includes a motor unit 20, a gear unit 50, and a casing 80. The drive device 10 is used as a drive source for an electric motorcycle, for example.

  The casing 80 includes a side wall 82 and end walls 84 and 86. The side wall 82 has a cylindrical shape. Each of the end walls 84 and 86 is disposed in the opening at the end of the side wall 82 and closes the side wall 82. The side wall 82 and the end walls 84 and 86 are each made of a steel material such as stainless steel.

(Configuration of motor unit)
In the following embodiment, the upper and lower sides are defined in the state of FIG. 1 regardless of the actual usage posture. For this reason, in the drive device 10, the gear unit 50 is disposed above the motor unit 20.

  The casing 80 accommodates the motor unit 20 and the gear unit 50. The motor unit 20 includes a motor output shaft 22, a rotor 24, and a stator 26. The motor unit 20 is a brushless motor. The stator 26 is fixed to the upper surface of the end wall 86. The stator 26 has a cylindrical shape that is disposed along the inner surface of the side wall 82. The stator 26 includes a core 30, a bobbin 32, and a plurality of coils 34.

  The core 30 is made of a magnetic material. The core 30 includes a cylindrical stator yoke 40 disposed along the inner surface of the side wall 82 on the outermost periphery of the stator 26, and a plurality of teeth 42 extending from the inner peripheral surface of the stator yoke 40 toward the center. . Each of the plurality of teeth 42 has the same rectangular parallelepiped shape. The plurality of teeth 42 are arranged at equal intervals in the circumferential direction of the stator yoke 40. For this reason, the interval between the teeth 42 adjacent to each other gradually increases toward the outside in the radial direction of the stator yoke 40.

  The core 30 is covered with a resin bobbin 32. The bobbin 32 covers the upper and lower ends of the stator yoke 40 and the surfaces of the plurality of teeth 42. A bobbin 32 that covers the lower end of the stator yoke 40 is disposed in contact with the upper surface of the end wall 86. The bobbin 32 covering the surface of the teeth 42 extending in the radial direction of the stator yoke 40 has a uniform thickness. A coil 34 is wound around a bobbin 32 that covers each tooth 42.

  The coil 34 is made of a conductive material. The outer dimension of the coil 34 gradually increases toward the outer side in the radial direction of the stator yoke 40 in accordance with the interval between adjacent teeth 42.

  The rotor 24 is disposed on the inner peripheral side of the plurality of teeth 42. The rotor 24 has a cylindrical shape facing the inner peripheral surface of the teeth 42. The rotor 24 is opposed to the inner peripheral surface of the tooth 42 with a slight gap. A plurality of permanent magnets are arranged on the surface of the rotor 24 facing the teeth 42 so that the magnetism is alternately different in the circumferential direction. A motor output shaft 22 is fixed at the center of the rotor 24.

  The motor output shaft 22 is made of a steel material such as stainless steel. The motor output shaft 22 extends linearly upward from the end wall 86 and extends to the gear portion 50 beyond the upper end of the stator 26. The lower end of the motor output shaft 22 has a planar shape and is in point contact with the upper end of a sphere 88 that is rotatably supported by the end wall 86. Thereby, when the motor output shaft 22 rotates while being in contact with the sphere 88, it is possible to suppress the rotation of the motor output shaft 22 from being inhibited by the contact between the motor output shaft 22 and the sphere 88. .

  The motor output shaft 22 is fixed to the rotor 24. A sun gear 28 is disposed in a portion of the motor output shaft 22 located in the gear portion 50. In the sun gear 28, a plurality of teeth are arranged at equal intervals on the outer peripheral surface of the motor output shaft 22. The sun gear 28 rotates around the center of the motor output shaft 22 as the motor output shaft 22 rotates. The motor output shaft 22 extends further upward from the upper end of the sun gear 28.

(Configuration of gear section)
The sun gear 28 is located in the gear unit 50. The gear unit 50 includes a plurality of planetary gears 52, a carrier 54, an internal gear 56, and a drive output shaft 58.

  A plurality (three in this embodiment) of planetary gears 52 are arranged around the sun gear 28 at equal intervals. In each planetary gear 52, a plurality of teeth are arranged on the outer peripheral surface at equal intervals. Each planetary gear 52 meshes with the sun gear 28. An internal gear 56 is disposed on the opposite side of the planetary gear 52 from the sun gear 28. The internal gear 56 is fixed to the side wall 82. The internal gear 56 has a cylindrical shape. The plurality of planetary gears 52 are arranged on the inner peripheral side of the internal gear 56. The internal gear 56 includes teeth that mesh with each of the plurality of planetary gears 52 on the inner peripheral surface thereof.

  In the gear unit 50, when the sun gear 28 rotates, each of the plurality of planetary gears 52 meshed with the sun gear 28 and the internal gear 56 revolves around the sun gear 28 while rotating.

  The plurality of planetary gears 52 are supported by a carrier 54 so as to be able to rotate. The carrier 54 has rotating portions 54a and 54b above and below the plurality of planetary gears 52, respectively. Each of the rotating portions 54a and 54b has an annular shape. The carrier 54 sandwiches the plurality of planetary gears 52 from above and below by the rotating portions 54a and 54b. A drive output shaft 58 is fixed at the center position of the rotating portion 54a located above. The drive output shaft 58 extends upward from the rotating portion 54 a, passes through the end wall 84 of the casing 80, and extends upward. A wheel of the two-wheeled vehicle is connected to the tip of the drive output shaft 58.

  The drive output shaft 58 extends on a straight line. At an intermediate position of the drive output shaft 58, the end wall 84 protrudes upward along the drive output shaft 58 and surrounds the drive output shaft 58. Two bearings 72 and 74 are disposed between the end wall 84 and the drive output shaft 58. The bearings 72 and 74 support the drive output shaft 58 so as to be rotatable with respect to the end wall 84.

  A recess 58a is arranged at the base end of the drive output shaft 58, that is, the end on the carrier 54 side. A bearing 58b is disposed in the recess 58a. An upper end portion of the motor output shaft 22 located above the sun gear 28 is inserted inside the bearing 58b. The motor output shaft 22 is inserted into the recess 58 a so as to be rotatable with respect to the drive output shaft 58. According to this configuration, it is possible to prevent the positional deviation between the drive output shaft 58 and the motor output shaft 22. In addition, by arranging the bearing 58b in the recess 58a, the motor output shaft 22 and the drive output shaft 58 can rotate at different rotational speeds.

  The rotating portion 54b located below the carrier 54 protrudes downward along the motor output shaft 22 and surrounds the motor output shaft 22 in the vicinity of the center thereof. The rotating part 54 b protrudes to the vicinity of the upper end of the rotor 24. One bearing 92 is disposed between the rotating portion 54 b and the motor output shaft 22. The bearing 92 supports the motor output shaft 22 so as to be rotatable with respect to the carrier 54.

(Configuration of heat radiation part)
The casing 80 includes a heat radiating portion 94. The heat radiating portion 94 has an annular shape that goes around the inner peripheral surface of the casing 80. The heat radiating portion 94 extends between the stator 26 and the rotating portion 54b. Thereby, the heat radiation part 94 can be arrange | positioned in the vicinity of the coil 34 of a heat-emitting part. In the driving device 10, the motor unit 20 and the gear unit 50 are accommodated in the casing 80. For this reason, in the structure which does not arrange | position the thermal radiation part 94, the thermal resistance from the heat generation source (namely, coil 34) of the motor part 20 to the casing 80 becomes high. By disposing the heat dissipating part 94, an increase in thermal resistance from the coil 34 to the casing 80 can be suppressed.

  The lower surface of the heat radiating portion 94 has a shape along the shape of the upper end of the coil 34. According to this configuration, the area of the heat radiating portion 94 facing the coil 34 can be increased. Thereby, the heat dissipation of the heat generated in the motor unit 20 can be improved. A jetty 96 that protrudes upward is disposed on the upper surface of the heat radiating portion 94. The jetty 96 has an annular shape that goes around the heat radiation part 94. According to this structure, the lubricating oil given to the gear part 50 can be kept on the heat radiating part 94. Thereby, the heat which generate | occur | produces in the motor part 20 can be radiated | emitted via lubricating oil.

(Operation of drive unit)
Next, the operation of the driving device 10 will be described. When three-phase AC power is supplied from an external power source (for example, a battery of a motorcycle) to the stator 26 of the motor unit 20, current flows through the coils 34 in a predetermined order, and the plurality of teeth 42 are magnetized. Thereby, the rotor 24 rotates. When the rotor 24 rotates, the motor output shaft 22 is rotated. As a result, the sun gear 28 rotates. When the sun gear 28 rotates, the plurality of planetary gears 52 revolve while rotating between the sun gear 28 and the internal gear 56. As a result, the rotation of the motor output shaft 22 is decelerated by the gear unit 50, the carrier 54 rotates with respect to the casing 80, and the wheels are driven. That is, the gear part 50 can also be called a reduction gear.

(Other effects)
In the drive device 10 described above, the motor output shaft 22 and the drive output shaft 58 can be integrated into one axis by inserting the motor output shaft 22 into the recess 58a of the drive output shaft 58. If one output shaft of the drive output shaft 58 is supported with respect to the casing 80, the other output shaft is also supported with respect to the casing 80. Thereby, the bearing fixed to the casing 80 can be decreased.

  The bearings 72 and 74 are fixed to the casing 80 on the opposite side of the carrier 54 from the motor unit 20. As a result, the drive output shaft 58 is rotatably supported with respect to the casing 80. According to this configuration, the bearings 72 and 74 can be arranged close to a position near the wheel of the drive output shaft 58, that is, a position to receive a force. Thereby, the force applied to the bearings 72 and 74 can be reduced.

  Further, the lower end of the motor output shaft 22 is in point contact with the upper end of the sphere 88. By supporting the motor output shaft 22 and the drive output shaft 58 with the bearings 72 and 74, it is not necessary to arrange a bearing for the casing 80 on the motor output shaft 22. In this configuration, the motor output shaft 22 is rotated in contact with the sphere 88 disposed in the casing 80. Thereby, when the motor output shaft 22 rotates while being in contact with the sphere 88, it is possible to suppress the rotation of the motor output shaft 22 from being inhibited by the contact between the motor output shaft 22 and the sphere 88. . Thereby, it can suppress that the lower end of the motor output shaft 22 is worn by rotation of the motor output shaft 22.

  Furthermore, in the drive device 10 described above, the motor unit 20 and the gear unit 50 are accommodated in one casing 80 and are not separated by a partition wall or the like. According to this configuration, the drive device 10 can be downsized in the vertical direction. In addition, by arranging the bearing 92 on the carrier 54, the motor output shaft 22 can be appropriately positioned with respect to the carrier 54. As a result, it is not necessary to separately provide a member for positioning the motor output shaft 92, and the drive device 0 can be simplified and downsized.

(Correspondence)
The bearing 92 is an example of “support portion” and “third bearing”, the bearing 58b is an example of “first bearing”, and the bearings 72 and 74 are examples of “second bearing”.

(Second embodiment)
With reference to FIG. 2, the driving device 200 according to the present embodiment will be described while referring to differences from the driving device 10 according to the first embodiment. The driving device 200 includes a motor output shaft 222 instead of the motor output shaft 22. Furthermore, the drive device 200 includes a drive output shaft 258 instead of the drive output shaft 58. The motor output shaft 222 includes a recess 222 a above the sun gear 28. The drive output shaft 258 includes a convex portion 258a inserted into a bearing 222b disposed in the concave portion 222a. In the modification, a bearing may be accommodated in the recess 222a. In this case, the convex part 258a may be inserted in the bearing. The drive output shaft 258 is connected to the rotating portion 54a of the carrier 54 at the outer periphery of the recess 222a.

  As mentioned above, although embodiment of this invention was described in detail, these are only illustrations and do not limit a claim. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

(1) In the first embodiment, the bearing 58 b is disposed in the recess 58 a at the base end of the drive output shaft 58. However, the bearing 58b may not be disposed in the recess 58a. In this case, the motor output shaft 22 may be slidably inserted into the recess 58a. Similarly, in the second embodiment, the bearing 222b may not be disposed in the recess 222b of the motor output shaft 222. In this case, for example, a lubricant such as grease or oil may be disposed in the recess 58a or the recess 222b.

(2) In each of the above embodiments, the heat radiation performance is improved by arranging the heat radiation portion 94. However, the configuration for improving the heat dissipation performance is not limited to this, and for example, a member having high heat transfer performance such as cotton-like metal may be disposed between the heat dissipation portion 94 and the stator 26. In this case, the heat radiation part 94 and the cotton-like metal are examples of the “heat radiation part”.

  Alternatively, the gap 300 may be disposed between the rotor 24, the internal gear 56, and the carrier 54 as shown in FIG. The gap 300 may be intermittently arranged in the circumferential direction of the driving apparatus 10 or may be arranged continuously.

(3) In the above embodiments, the lower ends of the motor output shafts 22 and 222 are in point contact with the sphere 88. In this configuration, the sphere 88 is an example of a “rotation inhibition suppression unit”. However, the lower ends of the motor output shafts 22 and 222 may be in direct contact with the end wall 86. In this case, the lower ends of the motor output shafts 22 and 222 may have a curved shape so as to make point contact with the end wall 86. In this modification, the curved shape at the lower end of the motor output shafts 22 and 222 is an example of a “rotation inhibition suppression unit”. Alternatively, the lower ends of the motor output shafts 22 and 222 may be supported by the end wall 86 via bearings.

(4) In each of the above embodiments, the drive output shaft 58 is rotatably disposed on the casing 80 via the bearings 72 and 74 that are directly supported by the casing 80. However, only one of the bearings 72 and 74 (for example, the bearing 74) may be disposed. In this case, a bearing that rotatably arranges the motor output shafts 22 and 222 in the casing 80 may be disposed. For example, a bearing that is directly supported by the end wall 86 may be disposed between the lower end of the motor output shaft 22 and the end wall 86.

  Or when only one bearing (for example, bearing 74) is arrange | positioned among the bearings 72 and 74, the bearing which arrange | positions the motor output shafts 22 and 222 to the casing 80 rotatably may not be arrange | positioned. .

  Alternatively, both of the bearings 72 and 74 may not be arranged. In this case, one or two bearings that are directly supported by the casing 80 and rotatably support the motor output shaft 22 on the casing 80 may be arranged.

(5) The heat dissipating part 94 may not be disposed, and the jetty 96 may not be provided.

(6) In each of the embodiments described above, the bearing 92 supports the motor output shaft 22 so as to be rotatable with respect to the carrier 54. However, the bearing 92 may not be disposed. For example, the carrier 54 and the motor output shaft 22 may be in direct contact. In this case, a concave groove extending in the rotation direction of the motor output shaft 22 is arranged in one of the carrier 54 and the motor output shaft 22 at the contact portion between the carrier 54 and the motor output shaft 22 and slidable in the other groove. The convex shape (for example, spherical convex shape) arrange | positioned may be arrange | positioned.

(7) The drive device 10 can be used for other devices such as a four-wheeled vehicle in addition to the two-wheeled vehicle.

  The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

DESCRIPTION OF SYMBOLS 10: Drive apparatus 20: Motor part 22: Motor output shaft 28: Sun gear 50: Gear part 52: Planetary gear 54: Carrier 56: Internal gear 58: Drive output shaft 58a: Concave 58b: Bearing 72: Bearing 74: Bearing 80: Casing 92: Bearing 94: Heat radiation part 96: Jetty 200: Drive device 222: Motor output shaft 222a: Concave part 222b: Bearing 258: Drive output shaft 258a: Convex part 300: Gap

Claims (8)

A motor comprising a motor output shaft having a sun gear;
A plurality of planetary gears meshing with the sun gear;
A carrier attached to the plurality of planetary gears and disposed rotatably with respect to the motor;
A drive output shaft fixed to the carrier and extending to the opposite side of the motor,
The motor output shaft passes through the carrier and extends to the drive output shaft;
One output shaft of the drive output shaft and the motor output shaft is in a recess disposed on the other output shaft of the drive output shaft and the motor output shaft, with respect to the one output shaft. A drive device that is rotatably inserted. The drive device according to claim 1,
The other output shaft includes a first bearing disposed in the recess,
The one output shaft is a drive device inserted in the first bearing. The drive device according to claim 1 or 2,
A casing fixed to the motor and rotatably supporting the carrier;
One or two second bearings fixed to the casing, and
Each of the said 2nd bearing is the drive device which supports either the said drive output shaft or the said motor output shaft rotatably with respect to the said casing. The drive device according to claim 3,
Each of the second bearings is fixed to the casing on the opposite side of the carrier to the motor, and supports the drive output shaft so as to be rotatable with respect to the casing. The drive device according to claim 3 or 4,
The end of the motor output shaft facing the casing on the side opposite to the drive output shaft, or the portion of the casing facing the drive output shaft and the end opposite to the end of the motor output shaft, The drive device in which the rotation inhibition suppression part which suppresses inhibition of rotation of the said motor output shaft is arrange | positioned. The drive device according to any one of claims 1 to 5,
The drive device further comprising a heat radiating part that radiates heat generated from the coil of the motor to the outside. It is a drive device as described in any one of Claim 1 to 6, Comprising:
The carrier is fixed to the carrier, and includes a support portion that rotatably supports the motor output shaft. The drive device according to claim 7,
The support unit includes a third bearing that rotatably supports the motor output shaft with respect to the carrier.

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