JP6560009B2 - Two-motor vehicle drive device - Google Patents

Description

  The present invention relates to a two-motor vehicle drive device including two electric motors and a speed reducer that are mounted on the upper side of a spring of a vehicle and independently drive left and right drive wheels.

  As a two-motor vehicle drive device including two electric motors and a speed reducer for independently driving left and right drive wheels, there is one disclosed in Patent Document 1.

  This type of two-motor vehicle drive device does not require a differential gear or the like that distributes the drive force of one electric motor to the left and right like a one-motor vehicle drive device that drives left and right drive wheels by one electric motor. Has the advantage.

  In addition, since the two-motor vehicle drive device is provided with an electric motor for driving independently for each of the left and right drive wheels, it is easy to vary the drive force of the left and right drive wheels. By generating a large amount of driving force on the wheels on the outside of the turn, it is easy to improve running performance such as turning performance.

Japanese Patent Laid-Open No. 11-243664

  As shown in FIG. 4, the conventional two-motor vehicle drive device includes left and right electric motors 101L and 101R that individually drive the left and right drive wheels, and speed reducers 102L and 102R that decelerate the rotation of the electric motors 101L and 101R. The reduction gears 102L and 102R are arranged in the center of the left and right electric motors 101L and 101R.

  As shown in FIG. 4, the speed reducers 102 </ b> L and 102 </ b> R are connected to drive wheels via an input shaft 123 having an input gear to which power is transmitted from the motor shaft 112, and a drive shaft including a constant velocity joint 126 and an intermediate shaft 127. This is a parallel shaft gear reducer that is arranged parallel to and offset from the output shaft 125 that transmits the driving force.

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

  As shown in FIG. 4, a constant velocity joint 126 is provided at the end of the output shaft 125 on the wheel side, and power is transmitted from the constant velocity joint 126 to the wheels via the intermediate shaft 127.

  The left and right speed reducers 102L and 102R are accommodated in parallel in a speed reducer casing 128.

  The input shaft 123, the intermediate shafts 124a and 124b, and the output shaft 125 of the left and right speed reducers 102L and 102R are arranged in parallel to each other, and the gears of each shaft are helical gears. Both ends of the reduction gear casing 128 are rotatably supported by rolling bearings. Further, the shaft centers of the gear shafts of the left and right speed reducers 102L and 102R are arranged coaxially with each other.

  Such a two-motor vehicle drive device needs to have a size that can be accommodated in the frame of the vehicle body, and downsizing of the entire device is essential.

  The intermediate shafts 124a and 124b are stepped gears each having a large diameter gear 124c and a small diameter gear 124d, and the small diameter gear 124d of the intermediate shaft 124b disposed on the output shaft 125 side is disposed outside in the axial direction. Therefore, since the output gear 125a of the output shaft 125 that meshes with the small-diameter gear 124d of the intermediate shaft 124b is also arranged on the outer side in the axial direction, the reduction gear that accommodates the output gear 125a of the output shaft 125 arranged on the outer side in the axial direction. The axial width of the speed reducer casing 128 increases, and the speed reducer casing 128 increases in size.

  For this reason, when the reduction gear casing 128 is enlarged, the installation space for the mounting bracket for fixing the two-motor vehicle drive device to the frame of the vehicle body also increases.

  In view of this, the present invention provides a two-motor vehicle drive device having a structure in which a reduction gear casing that accommodates two reduction gears in the left-right parallel is provided in the center and motor casings of two electric motors are fixedly arranged on the left and right sides of the reduction gear casing. In this case, the axial width of the reduction gear casing that accommodates the output gear of the output shaft of the reduction gear can be kept to a minimum, and an installation space for the mount bracket is to be secured on the side surface of the reduction gear casing.

  In order to solve the above-described problems, the present invention provides two electric motors for independently driving the left and right drive wheels, and the power of the two electric motors is individually decelerated and transmitted to the left and right drive wheels. The reduction gear includes an input shaft having an input gear to which power is transmitted from the motor shaft, and an output shaft having an output gear for transmitting a driving force to the drive wheels via the drive shaft. And one or more intermediate shafts having intermediate gears provided between the input shaft and the output shaft, with two speed reducer casings that accommodate the two speed reducers arranged in parallel on the left and right sides. In the two-motor vehicle drive device in which the motor casing of the electric motor is fixedly arranged, the intermediate shaft of the two left and right speed reducers has a small-diameter gear meshing with the output gear of the output shaft inside the axial direction and a large-diameter gear shaft Placed outside the direction And features.

  The reduction gear casing has a three-piece structure of a central casing and left and right side casings fixed to both side surfaces of the central casing, and a mounting bracket fixing space can be provided around the output shaft on the outer surface of the left and right side casings. .

  The mounting bracket fixing space is disposed on the side opposite to the intermediate shaft.

  As described above, according to the present invention, the small-diameter gear of the intermediate shaft that meshes with the output gears of the output shafts of the two left and right speed reducers is disposed on the inner side in the axial direction. The output gear of the shaft is arranged inside in the axial direction.

  Therefore, the axial width of the reduction gear casing can be minimized as compared with the case where the output gears of the left and right output shafts are arranged outside in the axial direction.

  When the reduction gear casing has a three-piece structure consisting of a central casing and left and right side casings fixed to both side surfaces of the central casing, a mounting bracket fixing space may be provided around the output shaft on the outer surface of the left and right side casings. it can.

It is a cross-sectional top view which shows embodiment of the 2 motor vehicle drive device which concerns on this invention. It is a schematic plan view which shows an example of the electric vehicle which uses the 2 motor vehicle drive device which concerns on this invention. It is the external view which looked at embodiment of FIG. 1 from back. It is a cross-sectional top view which shows the conventional 2 motor vehicle drive device.

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

  As shown in FIG. 1, the two-motor vehicle drive device A according to the present invention has a reduction gear casing 20 that accommodates two reduction gears 2L and 2R in parallel in the left and right directions. A structure in which motor casings 3L and 3R of the base electric motors 1L and 1R are fixedly arranged is adopted.

  The electric vehicle B shown in FIG. 2 is a front-wheel drive system, and includes a chassis 41, front wheels 42 as drive wheels, rear wheels 43, and a two-motor vehicle drive device A that independently drives left and right drive wheels. In the two-motor vehicle drive device A, a mount bracket (not shown) is fixed on the chassis 41 at the center position of the left and right front wheels 42 as drive wheels, and the drive force of the two-motor vehicle drive device A is a drive shaft. That is, it is transmitted to the left and right front wheels 42 via the constant velocity joint 15, the intermediate shaft 16 and the constant velocity joint 15.

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

  The left and right electric motors 1L, 1R in the two-motor vehicle drive device A according to the present invention are accommodated in motor casings 3L, 3R as shown in FIG.

  The motor casings 3L and 3R include cylindrical motor casing bodies 3aL and 3aR, and outer walls 3bL and 3bR which close the outer surfaces of the motor casing bodies 3aL and 3aR, and the speed reducer 2L on the inner surfaces of the motor casing bodies 3aL and 3aR. 2R and inner side walls 3cL and 3cR. The inner walls 3cL and 3cR of the motor casing bodies 3aL and 3aR are provided with openings for drawing out the motor shaft 12a.

  As shown in FIG. 1, the electric motors 1 </ b> L and 1 </ b> R are of a radial gap type in which a stator 11 is provided on the inner peripheral surface of the motor casing body 3 aL and 3 aR, and a rotor 12 is provided on the inner periphery of the stator 11. I am using something. Note that the electric motor (not shown) may be an axial gap type.

  The rotor 12 has a motor shaft 12a in the center, and the motor shaft 12a is drawn from the openings of the inner side walls 3cL and 3cR of the motor casing bodies 3aL and 3aR to the speed reducers 2L and 2R, respectively. A seal member 13 is provided between the openings of the motor casing bodies 3aL and 3aR and the motor shaft 12a.

  The motor shaft 12a is rotatably supported by the rolling bearings 14a and 14b on the inner side walls 3cL and 3cR and the outer side walls 3bL and 3bR of the motor casing bodies 3aL and 3aR (FIG. 1).

  As shown in FIG. 1, a speed reducer casing 20 that accommodates two speed reducers 2L and 2R provided in parallel in the left and right is a central casing 20a and left and right side casings 20bL fixed to both side surfaces of the central casing 20a. , 20bR three-piece structure.

  By fixing the outboard side (outside) side surfaces of the side casings 20bL and 20bR of the speed reducer casing 20 and the inner side walls 3cL and 3cR of the motor casing bodies 3aL and 3aR of the electric motors 1L and 1R with a plurality of bolts 29. The two electric motors 1L and 1R are fixedly arranged on the left and right sides of the reduction gear casing 20 (FIG. 1).

  As shown in FIG. 1, a partition wall 21 is provided at the center of the center casing 20a. The reduction gear casing 20 is divided into right and left parts by the partition wall 21, and independent left and right accommodation chambers for accommodating the two reduction gears 2L, 2R are provided in parallel.

  As shown in FIG. 1, the speed reducers 2L and 2R are provided symmetrically, and input shafts 23L and 23R each having an input gear 23a to which power is transmitted from the motor shaft 12a, and large diameters engaged with the input gear 23a. Intermediate shafts 24L and 24R having a small-diameter gear 24b meshing with the gear 24a and the output gear 25a, and an output gear 25a, which are pulled out from the speed reducer casing 20 through the constant velocity joint 15 and the intermediate shaft 16 (see FIG. 2). This is a parallel shaft gear reducer provided with output shafts 25L and 25R that transmit driving force to the drive wheels.

  Both ends of the input shafts 23L and 23R of the speed reducers 2L and 2R are provided with rolling bearings 28a and 28b on boss portions 27a formed on both left and right sides of the partition wall 21 of the central casing 20a and boss portions 27b formed on the side casings 20bL and 20bR. It is rotatably supported via.

  The end portions on the outboard side (outside) of the input shafts 23L and 23R are drawn outward from the openings provided in the side casings 20bL and 20bR, and between the openings and the outer ends of the input shafts 23L and 23R. Is provided with a seal member 31 to prevent leakage of lubricating oil sealed in the speed reducers 2L and 2R and intrusion of muddy water from the outside.

  The input shafts 23L and 23R have a hollow structure, and the motor shaft 12a is inserted into the hollow input shafts 23L and 23R. The input shafts 23L, 23R and the motor shaft 12a are coupled to each other by spline (including the serrations).

  The intermediate shafts 24L and 24R are stepped gears having a large-diameter gear 24a meshing with the input gear 23a and a small-diameter gear 24b meshing with the output gear 25a on the outer peripheral surface. The small diameter gear 24b of the intermediate shafts 24L and 24R is disposed on the inboard side (inside), and the large diameter gear 24a is disposed on the outboard side (outside). Both ends of the intermediate shafts 24L and 24R are supported by rolling bosses 34a and 34b on boss portions 32 formed on both surfaces of the partition wall 21 of the central casing 20a and boss portions 33 formed on the side casings 20bL and 20bR. Yes.

  The output shafts 25L and 25R have large-diameter output gears 25a, and rolling bearings 37a and 37b are formed on boss portions 35 formed on both surfaces of the partition wall 21 of the central casing 20a and boss portions 36 formed on the side casings 20bL and 20bR. Is supported by.

  The large-diameter output gears 25a of the output shafts 25L and 25R are arranged on the inboard side (inside) so as to mesh with the small-diameter gears 24b of the intermediate shafts 24L and 24R arranged on the inboard side (inside).

  The axial width of the speed reducer casing 20 that accommodates the output gear 25a of the output shafts 25L and 25R can be kept to a minimum width because the left and right output gears 25a are respectively arranged on the inboard side (inside). A mounting bracket fixing space 44 shown by cross hatching in FIGS. 1 and 3 can be provided around the output shafts 25L and 25R on the outer surfaces of the side casings 20bL and 20bR. The mount bracket fixing space 44 is disposed on the side opposite to the intermediate shafts 24L and 24R. In other words, the space on the opposite side of the output shafts 25L and 25R of the large diameter gear 24a of the intermediate shafts 24L and 24R can be effectively utilized. The mounting bracket fixing space can be arranged at a position overlapping the large-diameter gear 24a in the axial direction. Further, in this embodiment, since the volume of the speed reducer casing is reduced, the amount of lubricating oil is reduced, and the apparatus can be reduced in weight and ecology.

  Outboard side ends of the output shafts 25L and 25R are drawn out of the reduction gear casing 20 through openings formed in the side casings 20bL and 20bR, and are pulled out to the outboard side ends of the output shafts 25L and 25R. The outer joint member 15a of the constant velocity joint 15 is spline-coupled to the outer peripheral surface.

  The constant velocity joint 15 coupled to the output shafts 25L and 25R is connected to the drive wheels via the intermediate shaft 16 (FIG. 2).

  An oil seal 39 is provided between the end of the output shaft 25L, 25R on the outboard side and the opening formed in the side casings 20bL, 20bR, and leakage of the lubricating oil sealed in the speed reducers 2L, 2R and the outside Intrusion of muddy water from

  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.

1L, 1R: Electric motor 2L, 2R: Reducer 3L, 3R: Motor casing 3aL, 3aR: Motor casing body 3bL, 3bR: Outer wall 3cL, 3cR: Inner wall 11: Stator 12: Rotor 12a: Motor shaft 13: Seal Member 14a, 14b: Rolling bearing 15: Constant velocity joint 15a: Outer joint member 16: Intermediate shaft 20: Reduction gear casing 20a: Central casing 20bL, 20bR: Side casing 21: Partition walls 23L, 23R: Input shaft 23a: Input gear 24L, 24R: Intermediate shaft 24a: Large diameter gear 24b: Small diameter gears 25L, 25R: Output shaft 25a: Output gears 27a, 27b: Boss portions 28a, 28b: Rolling bearings 29: Bolts 31: Seal members 32, 33: Boss portions 34a, 34b: Rolling bearings 35, 36: Scan unit 37a, 37b: a rolling bearing 39: oil seal 41: Chassis 42: front wheel 43: rear wheel 44: Mounting bracket fixing spaces A: 2 Motor vehicle drive system B: electric vehicle

Claims (3)

  Two electric motors for independently driving the left and right drive wheels, and two reduction gears for individually decelerating the power of the two electric motors and transmitting them to the left and right drive wheels, An input shaft having an input gear to which power is transmitted from the motor shaft, an output shaft having an output gear for transmitting driving force to the drive wheels via the drive shaft, a large-diameter gear meshing with the input gear of the input shaft, and an output An intermediate shaft having a small-diameter gear that meshes with the output gear of the shaft, and the motor casings of the two electric motors are fixedly arranged on the left and right sides of the reduction gear casing that accommodates the two reduction gears in parallel on the left and right sides. In the two-motor vehicle drive device, the intermediate shaft of the two left and right speed reducers has a small-diameter gear that meshes with an output gear of the output shaft disposed inside the axial direction and a large-diameter gear disposed outside the axial direction. Two models to do Motor vehicle drive system.   The reducer casing has a three-piece structure consisting of a central casing and left and right side casings fixed to both side surfaces of the central casing, and a mounting bracket fixing space is provided around the output shaft on the outer surface of the left and right side casings. The two-motor vehicle drive device according to claim 1.   The two-motor vehicle drive device according to claim 2, wherein the mounting bracket fixing space is disposed on the opposite side to the intermediate shaft.

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