JP2010100215A - Drive unit of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drive unit of a vehicle capable of suppressing the enlargement of a body by suppressing the increase of dimensions in an axial direction. <P>SOLUTION: The drive unit includes a transmitting shaft 6 to which the power of a first motor generator 4 and an internal combustion engine 3 is transmitted through a power distributing mechanism 5, a rotor shaft 23 integrally rotated with a rotor 21 of a second motor generator 9, and a supporting wall 33 extending from a case 17 so as to cover a stator 20 of the second motor generator 9. On the supporting wall 33, a bearing holding portion 34 holding a bearing 31 for supporting the rotor shaft 23, and a bearing holding portion 38 holding a bearing 36 for supporting an end portion of the transmitting shaft 6 are formed. A bearing supporting portion 39 for supporting the end portion of the transmitting shaft 6 is disposed in a space S formed between an inner periphery of a coil end 20a of the stator 20 and an outer periphery of the rotor shaft 23. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle drive apparatus provided with an electric motor.

  As a vehicle drive device, a transmission shaft for transmitting power from a power distribution mechanism to which an internal combustion engine and a first motor / generator are respectively connected, and a rotor shaft of a second motor / generator are arranged separately and in parallel. A rotor shaft and a transmission shaft are connected via a gear train of parallel gears so that the rotation of the second motor / generator is decelerated and transmitted to the transmission shaft (Patent Document 1).

JP 2002-274201 A

  In the drive device of Patent Document 1, since the rotor shaft and the transmission shaft are connected by a gear train of parallel gears, when the end of the transmission shaft on the side where the gear train is provided is supported by a bearing, the bearing is a gear. It must be placed between the row and the second motor generator. Therefore, if these are arranged in the axial direction in the order of the second motor / generator, the bearing, and the gear train, the dimension in the axial direction tends to increase.

  Then, an object of this invention is to provide the drive device of the vehicle which can suppress the increase in a dimension by suppressing the increase in the dimension of an axial direction.

  The drive device of the present invention includes a predetermined drive source, a stator fixed to a case, and a rotor disposed on the inner periphery of the stator, an electric motor provided separately from the drive source, and the drive source. A transmission shaft that transmits the power of the motor, a rotor shaft that is arranged in parallel to and parallel to the transmission shaft, and rotates integrally with the rotor of the motor, and extends from the case so as to cover the stator of the motor. And a support wall that holds a first bearing that supports the rotor shaft and is provided at an edge of the through hole. A bearing holding portion and a second bearing holding portion that holds the second bearing that supports the end of the transmission shaft from a direction opposite to the direction in which the rotor shaft is inserted are formed, respectively. The bearing holder is a coil of the stator. In which is arranged in a space formed between an outer periphery of the inner circumference and the rotor shaft end (claim 1).

  According to this drive device, the first bearing holding portion and the second bearing holding portion provided on the support wall hold the first bearing that supports the rotor shaft and the second bearing that supports the transmission shaft, respectively. The second bearing holding portion is disposed in a space formed between the inner periphery of the stator coil end and the outer periphery of the rotor shaft. Therefore, the second bearing overlaps the coil end of the stator in the axial direction. Accordingly, the axial dimension can be shortened as compared with the case where the second bearing is arranged so as not to overlap the coil end. Therefore, since the increase in the dimension in the axial direction is suppressed, the increase in the physique can be suppressed.

  In one aspect of the drive device of the present invention, a drive gear provided on the rotor shaft, a driven gear provided on the transmission shaft and meshing with the drive gear, and a drive wheel side of the vehicle provided on the transmission shaft. A counter drive gear for transmitting power to the drive gear, wherein each tooth portion of the drive gear and the driven gear is located on an inner peripheral side with respect to a tooth portion of the counter drive gear, and the drive gear and Each tooth portion of the driven gear and the tooth portion of the counter gear may overlap in the axial direction (Claim 2). According to this aspect, each tooth portion of the drive gear and the driven gear is located on the inner peripheral side of the counter drive gear, and these tooth portions and the tooth portion of the counter drive gear overlap in the axial direction. . Therefore, even when the thickness of the tooth portion is increased in consideration of the strength of the tooth portion, the increase in the thickness can be absorbed by the overlap amount, so that the increase in the dimension in the axial direction can be prevented.

  In one aspect of the drive device of the present invention, the drive gear may be configured by a tooth portion being directly carved on the rotor shaft. In this case, unlike the case where the rotor shaft and the drive gear are configured separately and are spline-fitted, there is no backlash at the spline portion, so that the generation of abnormal noise can be prevented. Further, since a snap ring for fixing the rotor shaft and the drive gear is unnecessary, the number of parts can be reduced.

  An electric motor or an internal combustion engine may be provided as the predetermined drive source. For example, an internal combustion engine and another electric motor different from the electric motor are provided as the predetermined drive source, and an input shaft that receives the power of the internal combustion engine and is arranged coaxially with the transmission shaft, A power distribution mechanism having three elements capable of differential rotation, wherein the input shaft is connected to one of the elements, the other electric motor is connected to the other element, and the transmission shaft is connected to the other elements; , May further be provided (claim 4). Although this aspect is configured as a so-called hybrid vehicle drive device, since the increase in axial dimension is suppressed, the degree of freedom in layout of the electric motor, the internal combustion engine, other electric motors, and the power distribution mechanism is improved, and Mountability increases.

  As described above, according to the drive device of the present invention, the second bearing that supports the transmission shaft overlaps the coil end of the stator in the axial direction, so that the second bearing does not overlap the coil end. The axial dimension can be shortened as compared with the case of the arrangement in FIG. Therefore, since the increase in the dimension in the axial direction is suppressed, the increase in the physique can be suppressed.

  FIG. 1 schematically shows an overall configuration of a vehicle in which a driving apparatus according to an embodiment of the present invention is incorporated, and FIG. 2 shows in detail a main part of the driving apparatus shown in FIG. The vehicle 1 is configured as a so-called hybrid vehicle. As is well known, a hybrid vehicle is a vehicle that includes an internal combustion engine as a driving force source for traveling and also includes an electric motor as another driving force source for traveling. The vehicle 1 is configured as an FF layout vehicle in which drive wheels and an internal combustion engine are located at the front of the vehicle.

  The drive device 2 transmits the power from the internal combustion engine 3, the first motor / generator 4, the power distribution mechanism 5 to which the internal combustion engine 3 and the first motor / generator 4 are connected, and the power distribution mechanism 5. And a transmission shaft 6. The transmission shaft 6 is provided with a counter drive gear 7 for outputting power to the drive wheels 12 of the vehicle 1. Further, the drive device 2 is provided with a second motor / generator 9 connected to the transmission shaft 6 via a reduction gear train 8. The power of the counter drive gear 7 is transmitted to the left and right drive wheels 12 via the speed change mechanism 10 and the differential device 11.

  The internal combustion engine 3 is configured as a spark ignition type multi-cylinder internal combustion engine, and its power is transmitted to the power distribution mechanism 5 via the input shaft 15. The input shaft 15 is disposed coaxially with the transmission shaft 6. That is, the input shaft 15 and the transmission shaft 6 rotate around the common axis Ax1. A damper 16 (FIG. 2) is interposed between the input shaft 15 and the internal combustion engine 3, and torque fluctuations of the internal combustion engine 3 are absorbed by the damper 16.

  The first motor / generator 4 and the second motor / generator 9 have the same configuration, and have both a function as an electric motor and a function as a generator. The first motor / generator 4 includes a stator 18 fixed to a case 17 which is a fixing member, and a rotor 19 arranged coaxially on the inner peripheral side of the stator 18. Similarly, the second motor / generator 9 includes a stator 20 fixed to the case 17 and a rotor 21 disposed coaxially on the inner peripheral side of the stator 20. Coil ends 18a and 20a projecting in the axial direction are provided on both sides of the stators 18 and 20, respectively. The first motor / generator 4 corresponds to another electric motor according to the present invention, and the second motor / generator 9 corresponds to an electric motor according to the present invention.

  The power distribution mechanism 5 is configured as a single pinion type planetary gear mechanism having three elements that can rotate differentially with each other, and is arranged coaxially with the sun gear Su that is an external gear and the sun gear Su. A ring gear Ri that is an internal gear and a carrier Cr that holds the pinion 22 meshing with the gears Su and Ri so as to rotate and revolve freely. In this embodiment, the input shaft 15 is connected to the carrier Cr, the first motor / generator 4 is connected to the sun gear Su, and the transmission shaft 6 is connected to the ring gear Ri. Therefore, in this embodiment, the carrier Cr corresponds to any one element according to the present invention, the sun gear Su corresponds to one other element according to the present invention, and the ring gear Ri corresponds to the remaining elements according to the present invention. .

  The rotor 21 of the second motor / generator 9 is mounted on a rotor shaft 23, and the rotor shaft 23 rotates integrally with the rotor 21. The rotor shaft 23 is arranged separately from and parallel to the transmission shaft 6. That is, the rotor shaft 23 rotates about the axis Ax2 parallel to the axis Ax1 of the transmission shaft 6. As shown in FIG. 2, the rotor shaft 23 is rotatably supported by two bearings 30 and 31. One (left side in FIG. 2) bearing 30 is held by a bearing holding portion 32 formed in the case 17, and the other (right side in FIG. 2) bearing 31 is formed on a support wall 33 extending from the case 17. It is held by the bearing holding part 34.

  FIG. 3 shows a cross section taken along line III-III in FIG. As shown in FIGS. 2 and 3, the support wall 33 extends from the case 17 so as to cover the stator 20 of the second motor / generator 9. The bearing holding portion 34 is provided at an edge portion of the through hole 35 that is formed on the support wall 33 and into which the rotor shaft 23 is inserted. The transmission shaft 6 is rotatably supported by two bearings 36 and 37. The bearings 36 and 37 are held by bearing holding portions 38 and 39, the left bearing holding portion 38 in FIG. 2 is formed on the support wall 33, and the right bearing holding portion 39 in FIG. Is formed. The bearing holding portion 38 is configured to hold the bearing 36 from a direction opposite to the direction in which the rotor shaft 23 is inserted into the through hole 35, and the inner periphery of the coil end 20 a of the stator 20 and the outer periphery of the rotor shaft 23. Are arranged in a space S formed between the two. The bearing 31 that supports the rotor shaft 23 is the first bearing according to the present invention, the bearing 36 that supports the end of the transmission shaft 6 is the second bearing according to the present invention, and the bearing holding portion 34 that holds the bearing 31 is the main bearing. The bearing holding portion 38 for holding the bearing 36 corresponds to the first bearing holding portion according to the present invention and the second bearing holding portion according to the present invention, respectively.

  The reduction gear train 8 includes a drive gear 40 provided on the rotor shaft 23 and a driven gear 41 provided on the transmission shaft 6 and meshed with the drive gear 40. The drive gear 40 is configured by directly engraved teeth on the rotor shaft 23. Therefore, unlike the case where the rotor shaft 23 and the drive gear 40 are configured separately and are spline-fitted, no play is generated at the spline portion, so that the generation of abnormal noise can be prevented. Further, since a snap ring for fixing the rotor shaft 23 and the drive gear 40 is not required, the number of parts can be reduced. The driven gear 41 is disposed between the counter drive gear 7 and the bearing 36 and is splined to the outer periphery of the transmission shaft 6. The respective tooth portions of the drive gear 40 and the driven gear 41 are arranged on the inner peripheral side of the counter drive gear 7, and these tooth portions and the tooth portions of the counter drive gear 7 overlap in the axial direction.

  Although not shown in detail, the speed change mechanism 10 is configured as a mechanism that changes the rotation of the counter drive gear 7 and transmits it to the differential device 11. For example, a spur gear train may be provided as the speed change mechanism 10 and the counter drive gear 7 may be shifted at a single gear ratio and transmitted to the differential device 11. It is also possible to establish a plurality of gear ratios by providing a known planetary gear mechanism as the transmission mechanism 10 and selectively fixing each element of the planetary gear mechanism using a clutch, a brake, or the like.

  According to the above embodiment, the bearing 31 that supports the rotor shaft 23 and the bearing 36 that supports the transmission shaft 6 are held by the two bearing holding portions 34 and 38 provided on the support wall 33, respectively, and the stator A bearing holding portion 38 is disposed in a space S formed between the inner periphery of the 20 coil ends 20 a and the outer periphery of the rotor shaft 23. Therefore, the bearing 36 that supports the transmission shaft 6 overlaps the coil end 20a in the axial direction (left-right direction in the figure) (see FIG. 2). Therefore, the axial dimension can be shortened compared to the case where the bearing 36 is arranged so as not to overlap the coil end 20a. Therefore, since the increase in the dimension in the axial direction is suppressed, an increase in the physique can be suppressed. As a result, the drive device 2 is improved in the degree of freedom of layout of the internal combustion engine 3, the first motor / generator 4, the power distribution mechanism 5, and the second motor / generator 9, and is more easily mounted on the vehicle 1.

  Further, each tooth portion of the drive gear 40 and the driven gear 41 included in the reduction gear train 8 is located on the inner peripheral side of the counter drive gear 7, and these tooth portions and the tooth portions of the counter drive gear 7 are axial lines. Overlapping in the direction. Therefore, even when the thickness of the tooth portion is increased in consideration of the strength of these gears, the increase in the thickness can be absorbed by the overlap amount, so that the increase in the dimension in the axial direction can be prevented.

  The present invention is not limited to the above embodiment, and can be implemented in various forms within the scope of the gist of the present invention. The drive device of the present invention is not limited to being applied to a hybrid vehicle. For example, it is possible to configure a vehicle as an electric vehicle by mounting a drive device that includes an electric motor as another drive source but does not include an internal combustion engine. Further, the present invention is not limited to the drive device including the two electric motors and the internal combustion engine as described above, and the present invention can be implemented as, for example, a drive device including one electric motor and the internal combustion engine.

The figure which showed roughly the whole structure of the vehicle incorporating the drive device which concerns on one form of this invention. The figure which showed the principal part of the drive device shown by FIG. 1 in detail. Sectional drawing regarding the III-III line of FIG.

Explanation of symbols

1 Vehicle 3 Internal combustion engine (predetermined drive source)
4 First motor / generator (predetermined drive source, other electric motor)
5 Power distribution mechanism 6 Transmission shaft 7 Counter drive gear 9 Second motor / generator (electric motor)
12 Driving wheel 15 Input shaft 17 Case 20 Stator 20a Coil end 21 Rotor 23 Rotor shaft 31 Bearing (first bearing)
33 Support wall 34 Bearing holding portion (first bearing holding portion)
35 Through hole 36 Bearing (second bearing)
40 Drive Gear 41 Driven Gear S Space

Claims (4)

A predetermined drive source, a stator fixed to the case, and a rotor disposed on the inner periphery of the stator, an electric motor provided separately from the drive source, and transmission for transmitting power from the drive source A shaft, a rotor shaft that is arranged in parallel with and parallel to the transmission shaft, and rotates integrally with the rotor of the electric motor, and a support wall that extends from the case so as to cover the stator of the electric motor. Prepared,
The support wall includes a through-hole into which the rotor shaft is inserted, a first bearing holding portion that is provided at an edge of the through-hole and supports the rotor shaft, and a transmission shaft. A second bearing holding portion for holding a second bearing for supporting the end portion from a direction opposite to the direction in which the rotor shaft is inserted, respectively.
The drive device for a vehicle, wherein the second bearing holding portion is disposed in a space formed between an inner periphery of a coil end of the stator and an outer periphery of the rotor shaft. A drive gear provided on the rotor shaft; a driven gear provided on the transmission shaft and meshed with the drive gear; and a counter drive gear provided on the transmission shaft for transmitting power to the drive wheel side of the vehicle; Further comprising
The tooth portions of the drive gear and the driven gear are located on the inner peripheral side of the tooth portion of the counter drive gear, and the tooth portions of the drive gear and the driven gear and the tooth portion of the counter gear, The driving device according to claim 1, wherein the shafts overlap in the axial direction.   The drive device according to claim 1, wherein the drive gear is configured by a tooth portion being directly cut into the rotor shaft. As the predetermined drive source, an internal combustion engine and another electric motor different from the electric motor are provided,
An input shaft that receives the power of the internal combustion engine and is arranged coaxially with the transmission shaft, and three elements that can rotate differentially with respect to each other, and the input shaft serves as one of the other elements The drive device according to any one of claims 1 to 3, wherein the other electric motor further includes a power distribution mechanism in which the transmission shaft is connected to the remaining elements.

Images