JP2011084179A - Wheel motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wheel motor for incorporating both an electric motor and a brake device, and restraining heat transfer between the electric motor and the brake device. <P>SOLUTION: The wheel motor 1 includes: the electric motor 2 having a stator 21, and a rotor 22 disposed to the stator 21 to rotate freely and provided with a motor shaft 26; a reduction gear 3 provided with an output shaft 34 to which wheels provided at a vehicle are linked for decelerating rotation of the motor shaft 26 and outputting decelerated rotation from the output shaft; and a brake device 4 applying brake force to rotation of the wheels. The reduction gear 3 is disposed between the electric motor 2 and the brake device 4. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a wheel motor.

  In general, a vehicle is provided with a power device for applying driving force to wheels provided in the vehicle to drive the vehicle, and a brake device for applying braking force to the wheels to brake or stop the vehicle. As this brake device, a disc brake or a drum brake is used, and is arranged close to the wheel. And when a vehicle is an electric vehicle etc., many wheel motors which are equipped with an electric motor as a power source and are arrange | positioned in the vicinity of a wheel with a brake device are employ | adopted.

  As described above, when a wheel motor is used as a power device for a vehicle, since the brake device and the electric motor are arranged close to each other, the influence of heat generated from each of the brake device and the electric motor on the other party becomes a problem. .

  For example, when braking the vehicle, the brake device generates heat due to friction and becomes high temperature. When the electric motor becomes hot due to this heat, the performance of the magnet and the coil provided in the electric motor is lowered, and the output performance of the electric motor may be lowered. Further, when the electric motor is operated for a long time, the electric motor generates heat due to copper loss or iron loss and becomes high temperature. If the brake device becomes hot due to this heat, the friction performance of the friction material provided in the brake device may be reduced, and the braking performance of the brake device may be reduced.

  As described above, there has been proposed a vehicle in which the electric motor and the brake device are arranged with the wheel of the wheel interposed between the electric motor and the brake device, which are close to each other, in order to suppress the movement of heat transmitted to each other. (For example, Patent Document 1). In this vehicle, the movement of heat is suppressed between the electric motor and the brake device by arranging the wheel of the wheel between the electric motor and the brake device.

JP 2006-151359 A

  In the design of a vehicle such as an electric vehicle, there is a demand for integration of a plurality of components for ease of assembly and reduction in size and weight. In a wheel motor, an electric motor (including a reduction gear) and a brake device are integrated. That is, there is a need for a wheel motor incorporating both an electric motor and a brake device. However, in the above prior art, although the movement of heat between the electric motor and the brake device is suppressed, the electric motor and the brake device are disposed with the wheel of the wheel interposed therebetween. It cannot be a wheel motor incorporating both devices.

  Accordingly, the present invention has been made in view of the above-described circumstances, and provides a wheel motor that incorporates both an electric motor and a brake device and suppresses heat transfer between the electric motor and the brake device. is there.

  In order to solve the above-described problem, a wheel motor according to claim 1 is provided in a vehicle, and an electric motor having a stator, a rotor that is rotatably arranged with respect to the stator and provided with a motor shaft. A wheel motor comprising: an output shaft to which a wheel is linked; and a reduction device that decelerates rotation of the motor shaft and outputs rotation decelerated from the output shaft, wherein the wheel motor rotates the wheel A brake device that applies a braking force to the motor is provided, and the speed reducer is disposed between the electric motor and the brake device.

  The wheel motor according to claim 2 is the wheel motor according to claim 1, wherein the wheel motor includes shielding means for shielding between the speed reduction device and the electric motor and includes the speed reduction device in an airtight manner. The speed reducer case is configured such that an appropriate amount of oil is sealed in the speed reducer case.

  The wheel motor according to claim 3 is the wheel motor according to claim 2, wherein the brake device includes a brake drum to which a wheel provided in the wheel is coupled, and a brake shoe disposed in the brake drum. It is a drum brake provided, The drum brake is arranged inside the wheel.

    The wheel motor according to claim 4 is the wheel motor according to claim 3, wherein the reduction gear includes a sun gear integrally attached to the motor shaft of the electric motor, and an inner wall of the reduction gear case. An internal gear integrally attached to the sun gear, the sun gear and the internal gear, and at least one or more meshed with both the sun gear and the internal gear and linked with the output shaft A planetary gear device including a planetary gear.

  The wheel motor according to a fifth aspect is the wheel motor according to the fourth aspect, wherein the motor shaft and the output shaft of the electric motor are arranged coaxially.

  The wheel motor according to claim 6 is the wheel motor according to claim 5, wherein the wheel motor is integrally provided with the brake drum of the drum brake and to which the wheel of the wheel is attached. A connecting portion having a taper shape is formed at an end of the output shaft, and the plate member is taper-coupled to the connecting portion of the output shaft.

  A wheel motor according to a seventh aspect is the wheel motor according to the sixth aspect, wherein the electric motor is an outer rotor type brushless motor in which the rotor is disposed outside the stator.

  The wheel motor according to claim 8 is the wheel motor according to claim 7, wherein the wheel motor includes a front bracket and an end bracket that include the electric motor and the speed reducer, and the end bracket includes The electric motor is attached, and the front bracket is provided with an attachment portion attached to the vehicle.

  According to the wheel motor of the present invention, the wheel motor 1 is an all-in-one type wheel motor incorporating a brake device in addition to the electric motor and the reduction gear. Therefore, the wheel motor is a small and light wheel motor because it can be easily assembled to a vehicle and can share a housing and the like.

  Further, in the wheel motor, the speed reduction device is disposed between the electric motor and the brake device. Therefore, the heat generated in the electric motor and the brake device is suppressed from moving to the other party, and the output performance of the electric motor and the braking performance of the brake device are not reduced.

It is a front view of the wheel motor in the embodiment of the present invention. It is a longitudinal cross-sectional view of the wheel motor in embodiment of this invention. FIG. 3 is a cross-sectional view of the wheel motor shown in section AA in FIG. 2, and shows a brake device. It is a figure explaining operation | movement of the brake device in embodiment of this invention.

  Next, an embodiment of the present invention will be described based on FIG. 1, FIG. 2, and FIG. FIG. 1 is a front view of a wheel motor according to an embodiment of the present invention. FIG. 2 is a longitudinal sectional view of the wheel motor in the embodiment of the present invention. FIG. 3 is a cross-sectional view of the wheel motor shown in section AA in FIG. 2 and is a view showing a brake device.

  As shown in FIG. 1, the wheel motor 1 is attached to a vehicle frame F of a vehicle such as an electric vehicle or a hybrid vehicle with a mounting bolt B. A wheel 60 having a wheel 61 and a tire 62 attached to the wheel 61 is attached to the wheel motor 1 by a bolt 63. The wheel motor 1 gives driving force and braking force to the wheel 60 to control the traveling of the vehicle.

  As shown in FIG. 2, the wheel motor 1 includes an outer rotor type brushless motor (hereinafter also referred to as “brushless motor”) 2 as an electric motor, a planetary gear device 3 as a reduction gear, a drum brake 4 as a brake device, An end bracket 5, a front bracket 6, a plate member 56, and a speed reducer case 70 are provided. The brushless motor 2 and the planetary gear device 3 are enclosed in the end bracket 5 and the front bracket 6, and the planetary gear device 3 is further hermetically sealed by a reduction gear case 70 partially formed by the front bracket 6. It is described in

  The brushless motor 2 includes a stator 21, a rotor 22 that is rotatably disposed outside the stator 21, and a motor shaft 26 that is integrally attached to the rotor 22. The stator 21 has a stator core 21a formed by laminating a plurality of thin electromagnetic steel plates, and a coil 21c wound around the stator core 21a via an insulator 21b. The stator 21 is attached to the end bracket 5 by a stator bolt 21d.

  The rotor 22 includes a disk portion 22c and a back yoke 22b integrally formed on the outer periphery of the disk portion 22c. The rotor body 22a is formed in a bottomed cylindrical shape, and the inner wall of the back yoke 22b of the rotor body 22a. And a provided magnet 22d. A motor shaft 26 is attached to the inner periphery of the disk portion 22c of the rotor body 22a with screws 27.

Bearings (24, 25) are inserted and fixed to the end bracket 5, and the motor shaft 26 is pivotally supported on the bearings (24, 25), so that the rotor 22 is attached to the end bracket 5 via the motor shaft 26. The stator 21 is fixed so as to be rotatable. Thus, the stator 21 is attached to the end bracket 5 by the stator bolt 21d, and the motor shaft 26 attached to the rotor 22 is pivotally supported by the bearings (24, 25). It is attached to the end bracket 5.

  The brushless motor 2 is provided with a rotation detecting means 23 for detecting the rotational position of the rotor 22. The rotation detecting means 23 is provided with a detection sensor 23b, and a substrate 23a attached to the end bracket 5 and a detection magnet 23c attached to the disk portion 22c of the rotor body 22a at a position facing the detection sensor 23b. And. Note that a Hall IC or the like is used as the detection sensor 23b.

  In the present embodiment, as described above, the outer rotor type brushless motor 2 in which the rotor 22 is disposed outside the stator 21 is used as the electric motor. In the outer rotor type brushless motor 2, the rotor 22 as a rotor is disposed outside the stator 21, so that the torque radius can be increased and the motor shaft 26 can be rotated with high torque. Further, since the magnet 22d can be arranged on the inner wall of the back yoke 22b of the rotor 22, the magnet 22d is held from the radially outer side by the back yoke 22b, and the magnet 22d can be easily fixed to the back yoke 22b.

  Next, the reduction gear 2 of the present embodiment will be described based on FIG. The planetary gear device 2 as a reduction gear is provided with an output shaft 34 to which a motor shaft 26 is connected and wheels 60 provided in a vehicle are linked. The wheel motor 1 includes a reduction gear case 70 that hermetically encloses the planetary gear device 2. A part of the front bracket 6 and the reduction gear case 70 are sealed as shielding means that are integrally attached to the front bracket 6. A plate 39, an oil seal 40 disposed between the seal plate 39 and the motor shaft 26, and an oil seal 41 disposed between the front bracket 6 and the output shaft 34 are provided.

  The outer periphery of the oil seal 40 is in close contact with the seal plate 39, the inner periphery of the oil seal 40 and the outer periphery of the motor shaft 26 are slidable, and airtightness is maintained between the two. Similarly, the outer periphery of the oil seal 41 is in close contact with the front bracket 6, the inner periphery of the oil seal 41 and the outer periphery of the output shaft 34 are slidable, and the airtightness is maintained between the two. For this reason, the rotation of the motor shaft 26 and the output shaft 34 is not hindered, and the inside of the speed reduction device case 70 is kept airtight by the oil seals (40, 41).

  An appropriate amount of oil 42 is enclosed in the reduction gear case 70, and the planetary gear device 42 is disposed in a reduction gear case 70 in which an appropriate amount of oil 42 is enclosed. In addition, a seal plate 39 as a shielding means constituting the speed reducer case 70 is disposed between the brushless motor 2 and the planetary gear device 3. The oil 42 does not adhere to the brushless motor 2.

  The planetary gear device 3 includes a sun gear 31 that is integrally attached to the motor shaft 26, an internal gear 32 that is integrally attached to the inner wall of the front bracket 6 that forms the speed reducer case 70, and the sun gear 31. And three planetary gears (33, 33, 33) disposed between the internal gear 32 and meshing with both the sun gear 31 and the internal gear 32. The planetary gears (33, 33, 33) are pivotally supported by the connecting portions (35, 35, 35) formed integrally with the output shaft 34 via the bearings (36, 36, 36). . The output shaft 34 is pivotally supported by bearings (37, 38) disposed on the front bracket 6, and the motor shaft 26 and the output shaft 34 are disposed coaxially.

In the present embodiment, as described above, the planetary gear device 3 is used as a reduction gear. In the planetary gear device 3, the sun gear 31, the internal gear 32, and the planetary gears (33, 33, 33) can be arranged on the same plane and can be configured to be flat in the axial direction. Therefore, the axial length of the wheel motor 1 can be shortened. Moreover, since the sun gear 31, the internal gear 32, and the planetary gears (33, 33, 33) can be constituted by spur gears having high power transmission efficiency, the reduction efficiency is high. Further, as described above, the output shaft 34 that is an output can be arranged coaxially with respect to the motor shaft 26 that is an input. Therefore, the reduction gear and the electric motor can be arranged on the same axis, the outer diameter of the wheel motor 1 is reduced, and the layout of the wheel 60 into the wheel 61 is improved.

  In the present embodiment, the planetary gear device 3 is disposed in a reduction gear case 70 in which an appropriate amount of oil 42 is sealed. The planetary gear device 3 is separated between gears (31 and 33, 32 and 33 by oil lubrication). ) Is smooth and transmission efficiency is improved. Further, since the seal plate 39 as a shielding means for forming the speed reducer case 70 is disposed between the planetary gear device 3 and the brushless motor 2, the oil 42 does not adhere to the brushless motor 2. The oil 42 may contain burrs and wear powder generated from the gears (31, 32, 33). However, since the oil 42 does not adhere to the brushless motor 2, the gears (31, 32, 33) There is no possibility that the durability performance and output performance of the brushless motor 2 are deteriorated by burrs and wear powder generated from the above.

  Next, the brake device 4 of the present embodiment will be described based on FIGS. 2 and 3. The drum brake 4 is provided on the output shaft 34 side protruding from the planetary gear device 3, and is disposed on the opposite side of the brushless motor 2 with the planetary gear device 3 interposed therebetween. Accordingly, the planetary gear device 3 is disposed between the brushless motor 2 and the drum brake 4.

  The drum brake 4 as a brake device is rotatably supported by a front pin 6, a support pin 51 press-fitted and fixed to the front bracket 6, a pair of brake shoes (52, 52) arranged opposite to each other, and the front bracket 6. The brake cam 53, the brake arm 54 integrally attached to the brake cam 53, and the brake drum 55 containing the brake shoes (52, 52) are provided. As shown in FIG. 1, the drum brake 4 is disposed inside the wheel 61 of the wheel 60.

  The brake shoe 52 includes an arc-shaped brake shoe main body 52a and a friction member 52b attached to the outer arc wall of the brake shoe main body 52a. The friction member 52b is disposed at a position facing the inner wall of the brake drum 55. Yes. One end of the pair of brake shoes (52, 52) is rotatably supported by a cylindrical end 51a of the support pin 51, and the other end is a cam end 53a having a two-sided shape of the brake cam 53. The tension springs (57, 58) are attached to the pair of brake shoes (52, 52).

  The pair of brake shoes (52, 52) are attracted to each other by the tension springs (57, 58), with one end pivotally supported by the support pin 51 as a fulcrum and the other end contacting the brake cam 53 as an action point. It has a lever structure. A brake wire W from the vehicle is attached to an end of the brake arm 54 that is integrally attached to the brake cam 53, and the brake cam 53 to which the brake arm 54 is attached by a pulling operation of the wire W is as follows. Rotate.

  As shown in FIG. 4, when the brake cam 53 is rotated by the pulling operation of the wire W, the distance between the other ends of the brake shoes (52, 52) is increased by the cam end portion 53a having a two-sided shape. Thus, the friction members (52b, 52b) of the brake shoes (52, 52) are pressed against the inner wall of the brake drum 55, and a braking force due to friction is generated between the brake drum 55 and the friction members (52b, 52b).

  In the present embodiment, as described above, the drum brake 4 is used as the brake device instead of the disc brake. The disc brake includes a disc-shaped brake disc and a brake caliper having a brake shoe disposed on the outer periphery of the brake disc, and the brake caliper is disposed at a position away from the axle to increase the brake torque. Therefore, the disc brake becomes a brake device having a large radial length.

  On the other hand, the drum brake 4 is a brake device having a short radial length because the brake shoe 52 is disposed inside the cylindrical brake drum 55. For this reason, the drum brake 52 can be easily disposed inside the wheel 61 of the wheel 60, and many parts of the wheel motor 1 can be disposed inside the wheel 61 of the wheel 60. As a result, the overall size of the wheel motor 1 and the wheel 60 to which the wheel motor 1 is attached is reduced, and the layout of the vehicle is improved.

  The drum brake 4 is configured to generate a braking force by pulling the wire W. The tension of the wire W can be kept constant by a ratchet mechanism or the like provided in the vehicle. Therefore, the drum brake 4 can also be used as a so-called side brake used when the vehicle is stopped for a long time.

  Next, the fastening of the plate member 56 and the plate member 56 and the output shaft 34 according to the present embodiment will be described with reference to FIG. The plate member 56 is attached to the output shaft 34, and the wheel 61 of the wheel 60 is attached to the outer peripheral portion of the plate member 56 by bolts 63. A tapered connecting portion 34a is formed at the end of the output shaft 34 to which the plate member 56 is attached. The plate member 56 is inserted into the connecting portion and is tightened by the nut 43. The plate member 56 is connected by taper connection. It is fastened to the output shaft 34. The plate member 56 is integrally formed with a brake drum 55 of the drum brake 4.

  In the present embodiment, as described above, the plate member 56 is fastened to the output shaft 34 by taper coupling, so that the plate member 56 is fastened to the output shaft 34 without being displaced. Therefore, the wheel 60 attached to the output shaft 34 via the plate member 56 has almost no axial deviation with respect to the output shaft 34. Thereby, the wheel 60 can be rotated without shaking with respect to the output shaft 34, and the stable running of the vehicle can be realized.

  Next, attachment of the vehicle frame F of the wheel motor 1 will be described with reference to FIG. A mounting portion 6 a is integrally formed with the front bracket 6. Then, the wheel motor 1 is attached to the vehicle frame F of the vehicle by the bolt B. With such a configuration, the front bracket 6 is attached to the vehicle frame F, and the output shaft 34 to which the wheels 60 are attached to the front bracket 6 is supported. Therefore, the vehicle weight acts on the front bracket 6 and the vehicle weight does not act on the end bracket 5 to which the brushless motor 2 is attached. Therefore, the output performance of the brushless motor 2 does not change due to the vehicle weight.

The effect which the wheel motor 1 of this invention has is demonstrated based on this Embodiment.
(1) The wheel motor 1 is an all-in-one type wheel motor having a built-in drum brake 4 as a brake device in addition to a brushless motor 2 as an electric motor and a planetary gear device 3 as a reduction gear. Therefore, the wheel motor 1 is a small and light wheel motor that can be easily assembled to a vehicle and can share a housing and the like.
(2) In the wheel motor 1, the speed reduction device 3 is disposed between the electric motor 2 and the brake device 4. Therefore, the heat generated in the electric motor 2 and the brake device 4 is suppressed from moving to the other party, and the output performance of the electric motor 2 and the braking performance of the brake device 4 are not reduced.
(3) The reduction gear 3 disposed between the electric motor 2 and the brake device 4 is enclosed in a gas-tight manner by a reduction gear case 70 in which an appropriate amount of oil 42 is sealed. The reduction gear case 70 in which an appropriate amount of oil 42 is sealed has a large heat capacity and is disposed between the electric motor 2 and the brake device 4 in the same manner as the reduction gear 3. Therefore, it is further suppressed that the heat generated in each of the electric motor 2 and the brake device 4 moves to the other party.
Further, the reduction gear case 70 is provided with a seal plate 39 as a blocking means for blocking between the electric motor 2 and the reduction gear 3, and the oil 42 in the reduction gear case 70 adheres to the electric motor 2. There is nothing. Therefore, burrs, wear powder, etc. of the reduction gear 3 that may be confused with the oil 42 do not adhere to the electric motor 2, and the output performance of the electric motor 2 does not deteriorate due to burrs, wear powder, etc.

1 Wheel motor 2 Electric motor (outer rotor type brushless motor, brushless motor)
3 Reduction gear (planetary gear)
4 Brake device (drum brake)
5 End bracket 6 Front bracket 6a Mounting portion 21 Stator 21a Stator core 21b Insulator 21c Coil 21d Stator bolt 22 Rotor 22a Rotor main body 22b Back yoke 22c Disk portion 22d Magnet 26 Motor shaft 31 First sun gear 32 Second sun gear 33 Planetary gear 34 Output shaft 35 connecting part 39 Seal plate (shielding means)
40 Oil seal 41 Oil seal 42 Oil 51 Support pin 52 Brake shoe 53 Brake cam 54 Brake arm 55 Brake drum 56 Plate member 60 Wheel 61 Wheel 62 Tire 70 Reduction gear case F Vehicle frame

Claims (8)

An electric motor having a stator and a rotor that is rotatably arranged with respect to the stator and provided with a motor shaft;
A wheel motor comprising: an output shaft to which a wheel provided in a vehicle is linked; and a reduction device that decelerates rotation of the motor shaft and outputs rotation decelerated from the output shaft.
The wheel motor includes a brake device that applies a braking force to the rotation of the wheel,
The speed reduction device is disposed between the electric motor and the brake device.   The wheel motor has shielding means that shields between the reduction gear and the electric motor, and has a reduction gear case that hermetically encloses the reduction gear, and an appropriate amount of oil is enclosed in the reduction gear case. The wheel motor according to claim 1, wherein:   The brake device is a drum brake including a brake drum to which a wheel included in the wheel is coupled, and a brake shoe disposed in the brake drum, and the drum brake is disposed inside the wheel. The wheel motor according to claim 2.   The reduction gear includes a sun gear integrally attached to the motor shaft of the electric motor, an internal gear integrally attached to an inner wall of the reduction gear case, the first sun gear, and the inner gear. A planetary gear device comprising at least one or more planetary gears arranged between gears and meshing with both the first sun gear and the internal gear and linked with the output shaft. The wheel motor according to claim 3.   The wheel motor according to claim 4, wherein the motor shaft and the output shaft of the electric motor are arranged coaxially.   The wheel motor includes a plate member on which the brake drum of the drum brake is integrally provided and to which the wheel of the wheel is attached, and a tapered connecting portion is formed at an end of the output shaft. The wheel motor according to claim 5, wherein the plate member is taper-coupled to a connecting portion of the output shaft.   The wheel motor according to claim 6, wherein the electric motor is an outer rotor type brushless motor in which the rotor is disposed outside the stator.   The wheel motor includes a front bracket and an end bracket that contain the electric motor and the speed reducer. The electric motor is attached to the end bracket, and an attachment portion that is attached to the vehicle is attached to the front bracket. The wheel motor according to claim 7, wherein the wheel motor is provided.

Images