JP2017036788A - Vehicular motor drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular motor drive device A capable of decreasing device size in a diametrical direction and an axial direction, and reducing a cost of a device as compared with a case applying a planetary gear type speed reducer.SOLUTION: A gear speed reducer 2 is disposed close to a wheel, to an electric motor 1. A rotor shaft 8 of the electric motor 1 has a hollow portion 10 opening a gear speed reducer side end surface. An end portion on the electric motor 1 side of an output shaft 12 coaxially provided with the rotor shaft 8 is inserted in the hollow portion 10 of the rotor shaft 8. On an inner peripheral surface of the hollow portion of the rotor shaft 8, the output shaft 12 is rotation-supported to the rotor shaft 8 by at least one bearing 13. The gear speed reducer 2 is rotatably provided with one or more intermediate shaft 17 in parallel with the rotor shaft 8 and the output shaft 12. By engagement between a plurality of gears integrally provided on the intermediate shaft 17, and an input gear 11 and an output gear 15, rotations of the electric motor 1 is decelerated and transmitted to the output shaft 12.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a vehicle motor drive device that is mounted on a spring upper side of a vehicle and individually drives left and right drive wheels.

  As a vehicle motor drive device including an electric motor and a speed reducer that individually drive the left and right drive wheels, there are those disclosed in Patent Document 1 and Patent Document 2.

  Since this type of vehicle motor drive device includes an electric motor for driving independently for each of the left and right drive wheels, like a one-motor vehicle drive device in which the left and right drive wheels are driven by one common electric motor. There is an advantage that a differential gear or the like that distributes the driving force of one electric motor to the left and right is unnecessary.

JP 2010-48379 A JP 05-116539 A

  Incidentally, as shown in FIG. 6, the conventional vehicle motor drive device disclosed in Patent Document 1 decelerates the rotation of the electric motors 101L and 101R and the electric motors 101L and 101R that individually drive the left and right drive wheels. Reducers 102L and 102R are provided.

  As shown in FIG. 6, the speed reducers 102 </ b> L and 102 </ b> R include an input shaft 123 having an input gear to which power is transmitted from the motor shaft 112, and an output shaft 125 that transmits driving force to the driving wheels via the drive shaft 116. Is a parallel shaft gear reducer with a parallel and offset arrangement.

  One or more intermediate shafts 124 (counter shafts) are provided between the input shaft 123 and the output shaft 125 of the speed reducers 102L and 102R.

  As described above, when the motor shaft 112 and the output shaft 125 are arranged in parallel and offset, the speed reducers 102L and 102R are increased in size in the radial direction, which increases the mass of the vehicle motor drive device and deteriorates the vehicle mountability. Invite.

  Further, the vehicle motor drive device of Patent Document 2 uses a planetary gear type reduction gear as a reduction gear. Two electric motors are arranged back to back in the center, and the planetary gear type reduction gear is connected to each wheel. The structure is arranged on the side.

  Although the vehicle motor drive device of Patent Document 2 can eliminate the shaft to be offset by applying a planetary gear type speed reducer as a speed reducer and is advantageous for downsizing the device in the radial direction, There is a problem that the planetary gear type reduction gear is more expensive than the parallel shaft type gear reduction gear.

  Therefore, the present invention can reduce the device size in the radial direction and the axial direction, and can reduce the cost of the device as compared with the case where a planetary gear type reduction gear is applied. It is an object to provide an apparatus.

  In order to solve the above-described problems, a vehicle motor drive device according to the present invention includes two electric motors that respectively drive left and right wheels, and two gear reducers that decelerate the rotation of the respective electric motors. Gear reducers are arranged closer to the respective wheels, and the rotor shaft of the electric motor has a hollow portion opened on the gear reducer side end surface or a through-hole penetrating in the axial direction, and the gear reducer side end of the rotor shaft The input gear is integrally provided on the part, the output gear is integrally provided on the output shaft, the output shaft is provided coaxially with the rotor shaft, and the end of the output shaft on the electric motor side is the rotor. The shaft is inserted into the hollow portion or through hole of the shaft, and the output shaft is rotatably supported by at least one bearing with respect to the rotor shaft at the inner peripheral surface of the hollow portion or through hole of the rotor shaft. The intermediate axis of The rotation of the electric motor is decelerated and transmitted to the output shaft by meshing with the input gear and the output gear, which are provided rotatably in parallel with the input shaft and the output shaft, and are integrally provided with the intermediate shaft. Features.

  The vehicle motor drive device according to the present invention includes one electric motor and one gear reducer that decelerates the rotation of the electric motor. The gear reducer is disposed closer to the wheel with respect to the electric motor. The rotor shaft has a hollow part with an open end face on the gear reducer side or a through-hole penetrating in the axial direction. An input gear is integrally provided at the gear reducer side end part of the rotor shaft, and an output is provided on the output shaft. The gear is provided integrally, the output shaft is provided coaxially with the rotor shaft, and the end of the output shaft on the electric motor side is inserted into the hollow portion or through hole of the rotor shaft, and the hollow portion of the rotor shaft or On the inner peripheral surface of the through hole, the output shaft is rotatably supported by at least one bearing with respect to the rotor shaft, and the gear reducer is provided with one or more intermediate shafts that are rotatable in parallel with the input shaft and the output shaft. , Provided integrally with the intermediate shaft The rotation of the electric motor is decelerated and transmitted to the output shaft by meshing the plurality of gears with the input gear and the output gear.

  As described above, in the vehicle motor drive device of the present invention, the output shaft of the gear reducer arranged coaxially with the rotor shaft of the electric motor is connected to the hollow portion or the through-hole of the gear reducer side end portion of the rotor shaft. Since the electric motor side end portion of the output shaft is inserted and arranged, the axial length is shortened, and the apparatus length in the axial direction can be reduced. Further, a bearing that rotatably supports the gear reducer side end of the rotor shaft, and a bearing that rotatably supports the electric motor side end of the output shaft with respect to the hollow portion or through-hole of the gear reducer side end of the rotor shaft. By overlapping the positions in the axial direction, the length in the axial direction becomes shorter, so that the apparatus length in the axial direction can be further reduced. Furthermore, the support rigidity of the output shaft is increased, the durability of the speed reducer can be improved, and there is an effect in reducing vibration.

  Further, since all the gears of the gear reducer can be constituted by external gears, the cost of the apparatus can be reduced as compared with the case where a planetary gear type reducer is applied.

It is a cross-sectional top view which shows embodiment of this invention which integrated two electric motors and two gear reducers. It is sectional drawing of the II-II line of FIG. It is a schematic plan view which shows an example of the electric vehicle carrying the vehicle motor drive device of embodiment of FIG. It is a cross-sectional top view which shows embodiment of this invention which integrated one electric motor and one gear reducer. It is a schematic plan view which shows an example of the electric vehicle carrying the vehicle motor drive device of embodiment of FIG. It is a cross-sectional top view which shows the conventional vehicle motor drive device which integrated two electric motors and two gear reducers.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  A vehicle motor drive device A according to the present invention shown in FIG. 1 includes two electric motors 1 that respectively drive left and right wheels, and two gear reducers 2 that decelerate the rotation of each electric motor 1.

  A vehicle motor drive device A according to the present invention shown in FIG. 1 has a motor housing 3 that houses two electric motors 1 that respectively drive left and right wheels in parallel in the left and right sides. A reduction gear housing 4 is provided at the end, and the gear reduction gear 2 is accommodated and integrated in the reduction gear housing 4.

  In the vehicle motor drive device A of the present invention shown in FIG. 1, a motor housing 3 that houses two electric motors 1 is integrally formed, and an electric motor 1 and a gear reducer 2 that respectively drive left and right wheels are integrated. It is configured as one device. Here, integral molding includes integration of individually manufactured housings by screw fastening or the like.

  The motor housing 3 is provided with a partition wall 3 a in the center, the left and right end portions are opened, and the left and right end portions are closed by the speed reducer housing 4.

  The outer periphery of the motor housing 3 constitutes a so-called water jacket provided with a cooling pipe 5 to which a coolant is supplied from a radiator (not shown), thereby effectively cooling the electric motor 1.

  The speed reducer housing 4 connected to the left and right end portions of the motor housing 3 is provided integrally with the cylindrical portion 4a and the inner end portion of the cylindrical portion 4a, and closes the opening of the outer end portion of the motor housing 3. It consists of an inner wall 4b and an outer wall 4c provided at the outer end of the cylindrical portion 4a.

  As shown in FIG. 1, the electric motor 1 is a radial gap type in which a stator 6 is provided on the inner peripheral surface of the motor housing 3 and a rotor 7 is provided at an interval on the inner periphery of the stator 6. Yes. An axial gap type electric motor other than that shown in the figure may be used.

  A rotor shaft 8 is integrally attached to the center of the rotor 7. Two ends of the rotor shaft 8 are divided into a central partition wall 3a of the motor housing 3 and an inner wall 4b of the speed reducer housing 4 that closes an opening outside the motor housing 3 (on the side of the gear speed reducer 2). The motor housing 3 and the speed reducer housing 4 are rotatably supported by bearings 9a and 9b (same for rolling bearings).

  The outer end of the rotor shaft 8 (the end on the gear reducer 2 side) is inserted into the reducer housing 4, and the outer end of the rotor shaft 8 inserted into the reducer housing 4 is connected to the reducer housing. A hollow portion 10 that opens to the 4th side is provided. An input gear 11 is provided on the outer periphery of the outer end portion of the rotor shaft 8 inserted into the reduction gear housing 4. The input gear 11 may have a structure that is integrally formed with the rotor shaft 8 or a structure that is fitted with a spline or the like. In the embodiment of FIG. 1, the hollow portion 10 that opens to the reduction gear housing 4 side is provided at the outer end portion of the rotor shaft 8, but the hollow portion 10 may be a through hole that penetrates the rotor shaft 8.

  An angle sensor 24 is provided between the inner end of the rotor shaft 8 and the central partition wall 3 a of the motor housing 3.

  An output shaft 12 that is coaxially arranged with the rotor shaft 8 is provided in the speed reducer housing 4.

  The inner end portion (end portion on the electric motor 1 side) of the output shaft 12 is inserted into the hollow portion 10 at the outer end portion of the rotor shaft 8.

  The output shaft 12 inserted into the hollow portion 10 at the outer end of the rotor shaft 8 is rotatably supported with respect to the rotor shaft 8 by at least one bearing 13 (the same applies to rolling bearings). A bearing 13 that rotatably supports the output shaft 12 with respect to the rotor shaft 8 and a bearing 9b that rotatably supports the end of the rotor shaft 8 on the gear reducer 2 side with respect to the reducer housing 4 are positioned in the axial direction. It is arranged at the overlapping position.

  Further, the outer end portion of the output shaft 12 is rotatably supported on the outer wall 4c of the speed reducer housing 4 by a bearing 14 (the same applies to rolling bearings).

  An output gear 15 is integrally provided on the output shaft 12. The outer end portion of the output shaft 12 is pulled out from the outer wall 4 c of the reduction gear housing 4 to the outer wheel side, and a fastening portion for fitting the constant velocity joint 16 is provided.

  The gear reducer 2 is provided with one or more intermediate shafts 17, and the motor rotation speed is reduced and transmitted to the output shaft 12 by meshing with a plurality of gears, and finally, the constant velocity joint 16 and the intermediate shaft 18. Power is transmitted to the wheel 19 through the drive shaft consisting of (Fig. 3).

  Both ends of the intermediate shaft 17 are rotatably supported by the inner wall 4b and the outer wall 4c of the reduction gear housing 4 with respect to the reduction gear housing 4 by bearings 20 and 21 (the same applies to rolling bearings). The intermediate shaft 17 is a stepped gear having a large-diameter gear 17 a that meshes with the input gear 11 and a small-diameter gear 17 b that meshes with the output gear 15 on the outer peripheral surface.

  The reduction gear housing 4 is provided with a lubricating oil reservoir 22 for lubricating the gears in the reduction gear housing 4, and an oil seal 23 is enclosed between the outer wall 4 c of the reduction gear housing 4 and the output shaft 12. It is installed to prevent leakage of the lubricating oil and intrusion of muddy water from the outside. By making all the gears in the gear reducer 2 external gears, the gears lift up the lubricating oil in the lubricating oil reservoir 22 provided in the lower part of the internal space of the gear reducer 2 to perform lubrication.

  In the vehicle motor drive device A of the present invention, as described above, the output shaft 12 coaxially arranged with the rotor shaft 8 is connected to the hollow portion 10 at the outer end portion of the rotor shaft 8 and the inner end portion of the output shaft 12. By inserting and arranging, the axial length is shortened and the apparatus length in the axial direction can be reduced. Further, the bearing 9b for rotating and supporting the outer end of the rotor shaft 8 and the bearing 13 for rotating and supporting the inner end of the output shaft 12 with respect to the hollow portion 10 of the outer end of the rotor shaft 8 are positioned in the axial direction. By overlapping, the length in the axial direction becomes shorter, so that the device length in the axial direction can be further reduced. Furthermore, the support rigidity of the output shaft 12 is increased, the durability of the speed reducer can be improved, and there is an effect in reducing vibration.

  In addition, since the gear reducer 2 is constituted by an input gear 11 and an output gear 15 that are integrally provided on the rotor shaft 8, all the gears can be constituted by external gears. The cost of the apparatus can be reduced as compared with the case of applying.

  A vehicle motor drive device A according to the present invention comprises two electric motors 1 that respectively drive left and right wheels, and two gear reducers 2 that decelerate the rotations of the respective motors. Mounted on the chassis 51 at the center of the wheel 19, the driving force of the vehicle motor drive device A is transmitted to the left and right front wheels 19 via a drive shaft comprising the constant velocity joint 16 and the intermediate shaft 18.

  As a mounting form of the vehicle motor drive device A, any of a rear wheel drive system and a four wheel drive system may be used in addition to the front wheel drive system shown in FIG.

  The vehicle motor drive device A according to the embodiment shown in FIG. 4 includes one electric motor 1 and one gear reducer 2 that decelerates the rotation of the electric motor 1, and the vehicle motor drive according to the embodiment shown in FIG. The apparatus A is divided into two parts by the partition wall 3 a of the central motor housing 3.

  The gear reducer 2 is disposed closer to the wheel 19 with respect to the electric motor 1, and the rotor shaft 8 has a hollow portion 10 having an open end surface on the gear reducer 2 side or a through hole penetrating in the axial direction. An input gear 11 is integrally provided at the end of the electric motor 1 on the gear reducer 2 side of the rotor shaft 8, and an output gear 15 is integrally provided on the output shaft 12.

  The output shaft 12 is provided coaxially with the rotor shaft 8 of the electric motor 1, and the end of the output shaft 12 on the electric motor 1 side is inserted into the hollow portion 10 or the through hole of the rotor shaft 8, so that the rotor shaft 8 On the inner peripheral surface of the hollow portion 10, the output shaft 12 is rotatably supported by at least one bearing 13 with respect to the rotor shaft 8 of the electric motor 1.

  In the gear reducer 2, one or more intermediate shafts 17 are rotatably provided in parallel to the rotor shaft 8 and the output shaft 12, and a plurality of gears and an input gear 11 provided integrally with the intermediate shaft 17. The rotation of the electric motor 1 is decelerated by meshing with the output gear 15 and transmitted to the output shaft 12.

  In the embodiment of FIG. 4 as well, all the gears in the gear reducer 2 are external gears.

  As described above, the rotor shaft 8 is supported by the motor housing 3 by at least one bearing 13 at a position on the gear reducer 2 side with respect to the rotor 7 of the electric motor 1, and the output shaft 12 is hollow in the rotor 7. The bearing 13 that supports the inner peripheral surface of the portion 10 and the bearing 9b that rotatably supports the rotor shaft 8 on the gear reducer 2 side are arranged at positions that overlap in the axial direction.

  Since the vehicle motor drive device A shown in FIG. 4 includes one electric motor 1 and one gear reducer 2 that decelerates the rotation of the electric motor 1, when mounted on a vehicle, as shown in FIG. In addition, one vehicle motor drive device A is disposed on the wheel 19. FIG. 5 shows a front wheel drive vehicle, in which vehicle motor drive devices A are mounted on the chassis 51, one on each of the left and right front wheels, and the driving force of each vehicle motor drive device A is supplied to the constant velocity joint 16 and the intermediate shaft. This is transmitted to the front left and right wheels 19 via a drive shaft 18.

  The present invention is not limited to the above-described embodiments, and can of course be implemented in various forms without departing from the gist of the present invention. The scope of the present invention is claimed. The equivalent meanings recited in the claims, and all modifications within the scope.

DESCRIPTION OF SYMBOLS 1: Electric motor 2: Gear reduction gear 3: Motor housing 3a: Partition wall 4: Reduction gear housing 4a: Cylindrical part 4b: Inner side wall 4c: Outer wall 5: Pipe 6: Stator 7: Rotor 8: Rotor shaft 9a: Bearing 9b: Bearing 10: Hollow portion 11: Input gear 12: Output shaft 13: Bearing 14: Bearing 15: Output gear 16: Constant velocity joint 17: Intermediate shaft 17a: Large diameter gear 17b: Small diameter gear 18: Intermediate shaft 19: Wheel 20: Bearing 21: Bearing 22: Lubricating oil reservoir 23: Oil seal 24: Angle sensor 51: Chassis A: Motor drive device for vehicle

Claims (7)

  It consists of two electric motors that drive the left and right wheels, and two gear reducers that reduce the rotation of the electric motors. The gear reducers are arranged closer to the wheels with respect to the electric motor, and the rotor shaft of the electric motor Has a hollow part with an open end face on the gear reducer side or a through-hole penetrating in the axial direction, and an input gear is integrally provided at the gear reducer side end part of the rotor shaft, and an output gear is provided on the output shaft. The output shaft is provided coaxially with the rotor shaft, and the end of the output shaft on the electric motor side is inserted into the hollow portion or the through hole of the rotor shaft. The output shaft is rotatably supported by at least one bearing with respect to the rotor shaft, and the gear reducer has one or more intermediate shafts rotatably provided in parallel with the input shaft and the output shaft. Provided integrally with the shaft A motor drive apparatus for a vehicle characterized in that the rotation of the electric motor is decelerated by the meshing of the plurality of gears, the input gear and the output gear, and transmitted to the output shaft.   2. The vehicle motor drive device according to claim 1, wherein all gears in the gear reducer are external gears.   The bearing that rotates and supports the output shaft with respect to the rotor shaft and the bearing that rotates and supports the end of the rotor gear reducer side with respect to the reducer housing are arranged at positions where the axial positions overlap. The vehicle motor drive device according to claim 1.   It consists of one electric motor and one gear reducer that decelerates the rotation of the electric motor. The gear reducer is arranged closer to the wheel with respect to the electric motor, and the rotor shaft of the electric motor is hollow with the gear reducer side end face open. Or a through hole penetrating in the axial direction, an input gear is integrally provided at the gear reducer side end of the rotor shaft, an output gear is integrally provided on the output shaft, and the output shaft is a rotor The end of the output shaft on the electric motor side is inserted into the hollow portion or the through hole of the rotor shaft, and the output shaft is formed on the inner peripheral surface of the hollow portion or the through hole of the rotor shaft. A plurality of gears that are rotatably supported by at least one bearing with respect to the rotor shaft, and in which one or more intermediate shafts are rotatably provided in parallel to the input shaft and the output shaft in the gear reducer. And input gear and output gear The motor drive device for a vehicle is characterized in that the rotation of the electric motor is decelerated by the meshing of the motor and transmitted to the output shaft.   5. The vehicle motor drive device according to claim 4, wherein all gears in the gear reducer are external gears.   The bearing that rotates and supports the output shaft with respect to the rotor shaft and the bearing that rotates and supports the end of the rotor gear reducer side with respect to the reducer housing are arranged at positions where the axial positions overlap. The vehicle motor drive device according to claim 4.   A vehicle comprising at least two vehicle motor drive devices according to claim 4.

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