WO2019039045A1

WO2019039045A1 - Driving device

Info

Publication number: WO2019039045A1
Application number: PCT/JP2018/022081
Authority: WO
Inventors: 洋一川北; 安奈菊地; 杉本　篤
Original assignee: 愛三工業株式会社
Priority date: 2017-08-23
Filing date: 2018-06-08
Publication date: 2019-02-28
Also published as: JP2019039472A

Abstract

This driving device is provided with: a motor provided with a motor output shaft having a sun gear; a plurality of planetary gears engaging with the sun gear; a carrier attached to the plurality of planetary gears and rotatably arranged with respect to the motor; and a driving output shaft fixed to the carrier and extending toward the side opposite to the motor, wherein: the motor output shaft passes through the carrier and extends up to the driving output shaft; the carrier is provided with a support section which is fixed to the carrier and rotatably supports the motor output shaft; and one output shaft among the driving output shaft and the motor output shaft may be inserted in a recess section, disposed on the other output shaft among the driving output shaft and the motor output shaft, so as to be rotatable with respect to the one output shaft.

Description

Drive unit

The technology disclosed herein relates to a drive including a motor.

JP-A-2017-82871 discloses a drive device including a motor and a reduction gear. The motor is housed in a motor case. The reduction gear is accommodated in a reduction gear case. The motor output shaft is supported at its upper end by a bearing provided on the carrier of the reduction gear, and at its lower end by a bearing provided on the motor case.

In the above technique, the motor output shaft is positioned relative to the carrier via a 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 will be shifted. The present specification provides a technique for preventing misalignment between the motor output shaft and the drive output shaft.

The technology disclosed herein relates to a drive. The drive device is attached to a motor having a motor output shaft having a sun gear, a plurality of planet gears meshing with the sun gear, and the plurality of planet gears, and is rotatably disposed relative to the motor A carrier, and a drive output shaft fixed to the carrier and extending opposite to the motor, the motor output shaft passing through the carrier and extending to the drive output shaft, the drive One output shaft of the output shaft and the motor output shaft can be rotated 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, mutual displacement can be prevented by inserting one of the drive output shaft and the motor output shaft into the recess of the other output shaft.

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 be smoothly rotated in 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 the above may rotatably support either the drive output shaft or the motor output shaft with respect to the 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 bearings installed in the casing can be reduced.

Each of the second bearings may be fixed to the casing on the side of the carrier opposite to the motor, and may rotatably support the drive output shaft with respect to the casing. According to this configuration, the second bearing can be disposed close to the position receiving the force from the outside of the drive output shaft. Thereby, the force applied to the bearing can be reduced.

The end of the motor output shaft opposite to the drive output shaft opposite to the casing, or the part of the casing opposite to the end opposite to the drive output shaft of the motor output shaft, A rotation inhibition suppressing unit may be disposed to suppress the inhibition of the rotation of the motor output shaft. According to this configuration, the rotation of the motor output shaft with respect to the casing is inhibited even if the bearing is not disposed between the end facing the casing and the end on the opposite side of the drive output shaft of the motor output shaft and the casing. Can be suppressed.

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

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

The support portion may include a third bearing rotatably supporting the motor output shaft with respect to the carrier. According to this configuration, the motor output shaft can be smoothly supported by 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)
The drive device 10 of this embodiment will be described with reference to FIG. The drive device 10 includes a motor unit 20, a gear unit 50, and a casing 80. The drive device 10 is used, for example, as a drive source of an electric motorcycle.

The casing 80 comprises a side wall 82 and

end walls

84, 86. The side wall 82 has a cylindrical shape. The

end walls

84 and 86 are respectively disposed at the opening of the end of the side wall 82 and close 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 section)
In the following embodiment, the upper and lower sides are defined in the state of FIG. 1 regardless of the actual use 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 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. Core 30 includes cylindrical stator yoke 40 disposed along the inner surface of side wall 82 at the outermost periphery of stator 26 and a plurality of teeth 42 extending from the inner circumferential surface of 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 widens outward in the radial direction of the stator yoke 40.

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

The coil 34 is made of a conductive material. The external dimensions of the coil 34 are gradually increased outward in the radial direction of the stator yoke 40 in accordance with the distance between the teeth 42 adjacent to each other.

The rotor 24 is disposed on the inner circumferential side of the plurality of teeth 42. The rotor 24 has a cylindrical shape facing the inner circumferential surface of the teeth 42. The rotor 24 is opposed to the inner circumferential surface of the teeth 42 with a slight gap. On the surface of the rotor 24 facing the teeth 42, a plurality of permanent magnets are arranged so that their magnetism differs alternately 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 steel such as stainless steel. The motor output shaft 22 linearly extends upward from the end wall 86 and extends over the upper end of the stator 26 to the gear portion 50. The lower end of the motor output shaft 22 has a planar shape and is in point contact with the upper end of a spherical body 88 rotatably supported on the end wall 86. Thereby, when the motor output shaft 22 rotates in a state in which the motor output shaft 22 is in contact with the ball 88, the rotation of the motor output shaft 22 can be inhibited from being inhibited by the contact between the motor output shaft 22 and the ball 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 on 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 planet gears 52, a carrier 54, an internal gear 56, and a drive output shaft 58.

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

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

The plurality of planet gears 52 are rotatably supported by the carrier 54. The carrier 54 has rotating

portions

54 a and 54 b above and below the plurality of planet 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 in the vertical direction by the rotating

portions

54a and 54b. The drive output shaft 58 is fixed at the central position of the rotating portion 54a located at the upper side. The drive output shaft 58 extends upward from the rotating portion 54a, and extends upward through the end wall 84 of the casing 80. The wheels of the two-wheeled vehicle are connected to the tip of the drive output shaft 58.

The drive output shaft 58 extends in a straight line. In the intermediate position of the drive output shaft 58, the end wall 84 projects upwardly along the drive output shaft 58 to surround the drive output shaft 58. Two

bearings

72, 74 are disposed between the end wall 84 and the drive output shaft 58. The

bearings

72, 74 rotatably support the drive output shaft 58 with respect to the end wall 84.

A recess 58 a is disposed at the proximal 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 rotatably inserted into the recess 58 a with respect to the drive output shaft 58. According to this configuration, mutual displacement between the drive output shaft 58 and the motor output shaft 22 can be prevented. Further, by disposing the bearing 58b in the recess 58a, the motor output shaft 22 and the drive output shaft 58 can be rotated at different rotational speeds.

The rotary portion 54 b located at the lower part of the carrier 54 protrudes downward along the motor output shaft 22 around the center of the carrier 54 to surround the motor output shaft 22. The rotating portion 54 b protrudes up to near 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 rotatably supports the motor output shaft 22 with respect to the carrier 54.

(Structure of heat dissipation unit)
The casing 80 includes a heat dissipation unit 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. Thus, the heat radiating portion 94 can be disposed in the vicinity of the coil 34 of the heat generating portion. In the drive device 10, the motor unit 20 and the gear unit 50 are accommodated in the casing 80. Therefore, in the configuration in which the heat dissipation portion 94 is not disposed, the thermal resistance from the heat generation source (i.e., the coil 34) of the motor portion 20 to the casing 80 is high. By arranging the heat radiating portion 94, it is possible to suppress an increase in thermal resistance from the coil 34 to the casing 80.

The lower surface of the heat radiating portion 94 has a shape that conforms to the shape of the upper end of the coil 34. According to this configuration, it is possible to increase the area facing the coil 34 of the heat radiating portion 94. Thereby, the heat dissipation of the heat generated by the motor unit 20 can be improved. Further, a jetty 96 protruding 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 radiating portion 94. According to this configuration, the lubricating oil applied to the gear portion 50 can be kept on the heat radiating portion 94. Thus, the heat generated by the motor unit 20 can be dissipated through the lubricating oil.

(Operation of drive unit)
Next, the operation of the drive device 10 will be described. When three-phase alternating current power is supplied from an external power source (for example, a battery of a two-wheeled vehicle) to the stator 26 of the motor unit 20, current flows in a plurality of 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 planet 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, and the carrier 54 rotates relative to the casing 80 to drive the wheels. That is, the gear unit 50 can also be referred to as 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 made uniaxial by inserting the motor output shaft 22 into the recess of the drive output shaft 58, and the motor output shaft 22 and If one output shaft of the drive output shaft 58 is supported on the casing 80, the other output shaft is also supported on the casing 80. Thus, the number of bearings fixed to the casing 80 can be reduced.

Further,

bearings

72, 74 are fixed to the casing 80 on the opposite side of the carrier 54 to the motor unit 20. Thus, the drive output shaft 58 rotatably supports the casing 80. According to this configuration, the

bearings

72, 74 can be disposed close to the wheel near the wheel of the drive output shaft 58, that is, the position receiving the 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 ball 88. By supporting the motor output shaft 22 and the drive output shaft 58 by the

bearings

72 and 74, it is not necessary to arrange the 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 ball 88 disposed in the casing 80. Thereby, when the motor output shaft 22 rotates in a state in which the motor output shaft 22 is in contact with the ball 88, the rotation of the motor output shaft 22 can be inhibited from being inhibited by the contact between the motor output shaft 22 and the ball 88 . Thus, the lower end of the motor output shaft 22 can be prevented from being worn by the rotation of the motor output shaft 22.

Furthermore, in the above-described drive device 10, 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 miniaturized in the vertical direction. Further, by disposing the bearing 92 on the carrier 54, the motor output shaft 22 can be properly positioned relative to the carrier 54. As a result, the drive device 0 can be simplified and miniaturized without the need to separately provide a member for positioning the motor output shaft 92.

(Correspondence relationship)
The bearing 92 is an example of the “support portion” and the “third bearing”, the bearing 58 b is an example of the “first bearing”, and the

bearings

72 and 74 are examples of the “second bearing”.

Second Embodiment
With reference to FIG. 2, the differences between the drive device 200 of the present embodiment and the drive device 10 of the first embodiment will be described. The drive 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 protrusion 258a inserted into a bearing 222b disposed in the recess 222a. In the modification, a bearing may be accommodated in the recess 222a. In this case, the convex portion 258a may be inserted into the bearing. The drive output shaft 258 is connected to the rotating portion 54a of the carrier 54 on the outer periphery of the recess 222a.

As mentioned above, although embodiment of this invention was described in detail, these are only an illustration and do not limit a claim. The art set forth in the claims includes various variations and modifications of the specific examples illustrated above.

(1) In the first embodiment described above, the bearing 58 b is disposed in the recess 58 a at the proximal 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. Also in the second embodiment described above, the bearing 222 b may not be disposed in the recess 222 b 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 dissipation performance is improved by arranging the heat dissipation portion 94. However, the configuration for improving the heat dissipation performance is not limited to this. For example, a member having a high heat transfer performance, such as a cotton-like metal, may be disposed between the heat dissipation portion 94 and the stator 26. In this case, the heat radiating portion 94 and the cotton-like metal are examples of the “heat radiating portion”.

Alternatively, instead of the heat radiating portion 94, as shown in FIG. 3, a gap 300 may be disposed between the rotor 24 and the internal gear 56 and the carrier 54. The gap 300 may be disposed intermittently in the circumferential direction of the drive device 10, or may be disposed continuously in a circle.

(3) In each of the above embodiments, the lower ends of the

motor output shafts

22 and 222 are in point contact with the ball 88. In this configuration, the sphere 88 is an example of the “rotation inhibition suppressing portion”. However, the lower end of the

motor output shaft

22, 222 may be in direct contact with the end wall 86. In this case, the lower ends of the

motor output shafts

22, 222 may have a curved shape so as to make point contact with the end wall 86. In this modification, the curved shape of the lower ends of the

motor output shafts

22 and 222 is an example of the “rotation inhibition suppressing portion”. Alternatively, the lower end of the

motor output shaft

22, 222 may be supported by the end wall 86 via a bearing.

(4) In each of the above-described embodiments, the drive output shaft 58 is rotatably disposed in the casing 80 via the

bearings

72, 74 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 may be disposed which rotatably arranges the

motor output shafts

22 and 222 in the casing 80. For example, a bearing supported directly on the end wall 86 may be disposed between the lower end of the motor output shaft 22 and the end wall 86.

Alternatively, when only one of the bearings 72 and 74 (for example, the bearing 74) is disposed, the bearing that rotatably disposes the

motor output shaft

22 or 222 on the casing 80 may not be disposed. .

Alternatively, both of the

bearings

72 and 74 may not be disposed. In this case, one or two bearings supported directly on the casing 80 and rotatably supporting the motor output shaft 22 on the casing 80 may be disposed.

(5) The heat dissipation unit 94 may not be disposed, and may not include the jetty 96.

(6) In each of the above embodiments, the bearing 92 rotatably supports the motor output shaft 22 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 with each other. In this case, at a contact portion between the carrier 54 and the motor output shaft 22, a recessed groove extending in the rotational direction of the motor output shaft 22 is disposed on one of the carrier 54 and the motor output shaft 22, and the other can slide in the recessed groove The convex shape (for example, spherical convex shape) arrange | positioned at may be arrange | positioned.

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

The technical elements described in the present specification or the drawings exhibit technical usefulness singly or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the techniques illustrated in the present specification or the drawings simultaneously achieve a plurality of purposes, and achieving one of the purposes itself has technical utility.

Claims

A motor comprising a motor output shaft having a sun gear;
A plurality of planet gears meshing with the sun gear;
A carrier attached to the plurality of planet gears and rotatably disposed relative to the motor;
And a drive output shaft fixed to the carrier and extending opposite to the motor.
The motor output shaft extends through the carrier 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 relative to the one output shaft The drive is rotatably inserted.
The driving device according to claim 1,
The other output shaft comprises a first bearing disposed in the recess,
The drive device, wherein the one output shaft is inserted into the first bearing.
A driving device according to claim 1 or 2, wherein
A casing fixed to the motor and rotatably supporting the carrier;
And one or two second bearings fixed to the casing.
Each of the second bearings rotatably supports one of the drive output shaft and the motor output shaft with respect to the casing.
The driving device according to claim 3,
The second bearing is fixed to the casing on the opposite side of the carrier to the motor, and the second bearing supports the drive output shaft rotatably relative to the casing.
It is a drive device of Claim 3 or 4, Comprising:
The end of the motor output shaft opposite to the drive output shaft opposite to the casing, or the part of the casing opposite to the end opposite to the drive output shaft of the motor output shaft, A driving device, wherein a rotation inhibition suppressing portion is disposed which suppresses inhibition of rotation of the motor output shaft.
The driving device according to any one of claims 1 to 5, wherein
A driving device, further comprising: a heat radiating portion that radiates heat generated from a coil of the motor to the outside.
A driving device according to any one of claims 1 to 6, wherein
The driving device, wherein the carrier is fixed relative to the carrier and includes a support that rotatably supports the motor output shaft.
The driving device according to claim 7, wherein
The drive unit, wherein the support portion includes a third bearing that rotatably supports the motor output shaft with respect to the carrier.