JP2007159287A - Motor support mechanism of drive unit for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor support mechanism of a drive unit for a vehicle that can make the drive unit compact and that increases the easiness in assembling. <P>SOLUTION: Both ends of a first rotor shaft 42 of a first electric motor 20 are supported rotatably via needle bearings 48, 50 provided on the outside circumferential surface of an input shaft 18 and supported in the direction of axial center with thrust needle bearings 54, 58 arranged at the ends of the direction of the axial center of the first rotor shaft 42. By using the needle bearings to support the first rotor shaft 42, the space for mounting the bearings can be minimized so that the drive unit 10 can be made compact. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a drive device for a vehicle, and more particularly to a motor support mechanism provided in the drive device.

  2. Description of the Related Art A vehicle drive device that includes a power distribution mechanism that distributes the output of a driving force source such as an engine to an electric motor and an output member is known. For example, this is a hybrid vehicle drive device described in Non-Patent Document 1. Non-Patent Document 1 includes two electric motors, a generator mainly functioning for power generation and a motor mainly functioning for driving. In addition, two planetary gear units, which are a planetary gear unit for power distribution that distributes engine power to the generator and the output member, and a planetary gear unit for reduction that decelerates the rotation of the motor, are provided on the same axis. . In such a drive device, it is possible to control the rotation speed of the output member steplessly by controlling the electrical load applied to the electric motor, and the vehicle can be run while maintaining the engine in an optimum state. it can.

New car manual Toyota Harrier Hybrid (issued in March 2005)

  By the way, in the vehicle drive device described in Non-Patent Document 1, the rotor shafts of the generator and the motor are respectively connected at both ends by ball bearings press-fitted into the inner peripheral edge of the case wall extending from the outer periphery of the housing case to the inner peripheral side. It is rotatably supported. That is, the rotor shaft is supported by the housing case via the ball bearing. In such a support mechanism, there are many processes for press-fitting the ball bearing into the case wall, which causes a problem in assembling. In addition, since the ball bearings that support each rotor shaft are fitted on the outer periphery of the rotor shaft, the inner diameter of the ball bearing that supports the rotor shaft becomes larger, so the ball bearing itself is enlarged and mounted. As a result, the vehicle drive device may be increased in size.

  In Non-Patent Document 1, the rotor shaft of the generator is connected to the sun gear of the power distribution mechanism by spline fitting. There is a problem that the shaft length of the vehicle drive device becomes long due to the spline fitting portion. In order to solve this problem, the shaft length can be shortened by integrally forming the rotor shaft of the generator and the sun gear. However, due to the problem of assembly, the inner diameter of the ball bearing is made larger than the outer diameter of the sun gear. Otherwise, since the assembly is impossible, the inner diameter of the ball bearing has to be increased, resulting in an increase in the size of the vehicle drive device, which did not solve the problem.

  The present invention has been made against the background of the above circumstances, and the object of the present invention is to make it possible to make the vehicle drive device compact and to further improve the assembling performance. To provide a mechanism.

  In order to achieve the above object, the gist of the invention according to claim 1 is that: (a) a rotating shaft having one end connected to the engine, and a first shaft disposed sequentially on a coaxial axis of the rotating shaft; A vehicle comprising: an electric motor and a second electric motor; and a power distribution mechanism that is interposed between the first and second electric motors and distributes the driving force of the engine and the first and second electric motors using planetary gears. (B) The rotating shaft is rotatably supported at both ends thereof via a pair of ball bearings fixed to a case wall of a housing case which is a non-rotating member, and (c) the first A rotor shaft that supports at least one rotor of the first and second electric motors is rotatably supported on the rotation shaft via a roller bearing disposed on the outer periphery of the rotation shaft, and the case wall or the rotation Axis and front By intervening been thrust roller bearing between the axial end of the rotor shaft, the rotor shaft, characterized in that it is supported in the axial direction.

  According to a second aspect of the present invention, there is provided a motor support mechanism for a vehicle drive device according to the first aspect, wherein a rotor shaft of the first or second motor is integrated with a sun gear of the power distribution mechanism. It is characterized by being molded.

  According to the motor support mechanism of the vehicle drive device of the first aspect of the present invention, at least one rotor shaft of the first motor and the second motor is a rotary shaft whose both ends are rotatably supported by ball bearings. It is rotatably supported via a roller bearing disposed on the outer peripheral surface, and is supported in the axial direction by a thrust roller bearing disposed at an axial end of the rotor shaft. That is, the rotor shaft is supported by the rotating shaft via the roller bearing, and is supported by the case wall of the housing case or the rotating shaft via the thrust roller bearing. Thus, by changing the support mechanism of the rotor shaft from the conventional ball bearing to the roller bearing, the space for mounting the bearing is reduced as a whole, and as a result, the vehicle drive device can be made compact. Moreover, since the process of press-fitting the ball bearing can be reduced by eliminating the ball bearing, the assemblability can be improved.

  According to the motor support mechanism of the vehicle drive device of the invention according to claim 2, even if the rotor shaft and the sun gear of the power distribution mechanism are integrally formed by supporting the rotor shaft with the roller bearing, There are no restrictions on assembly such as increasing the inner diameter of the roller bearing. As a result, integral molding is possible, and by performing integral molding, the spline fitting portion between the rotor shaft and the sun gear can be eliminated, and the shaft length of the vehicle drive device can be shortened accordingly.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a skeleton diagram illustrating a drive device 10 for a hybrid vehicle according to an embodiment of the present invention. In FIG. 1, the drive device 10 pulsates due to torque fluctuations or the like from the engine 14 in order from the engine 14 side in a housing case 12 (hereinafter referred to as case 12) that is a non-rotating member attached to the vehicle body. Absorbing damper 16, input shaft 18 rotated by engine 14 through damper 16, first electric motor 20, first planetary gear device 22 functioning as a power distribution mechanism, and second planetary gear device functioning as a speed reducer 24 and a second electric motor 26.

  This drive device 10 is suitably used for an FF (front engine / front drive) type vehicle that is placed horizontally in the vehicle, and the output of the engine 14 is a drive wheel via a counter gear and a differential gear device (not shown). Is transmitted to. In addition, since the drive apparatus 10 is comprised substantially symmetrically with respect to the shaft center, the lower half is abbreviate | omitted.

  Both ends of the input shaft 18 are rotatably supported by ball bearings 28 and 30, and one end is connected to the engine 14 via the damper 16 to be driven to rotate. The first planetary gear device 22 functions as a power distribution mechanism, and is a mechanical mechanism that mechanically distributes the output of the engine 14 transmitted to the input shaft 18, and outputs the output of the engine 14 to the first electric motor 20 and the output gear. 32. The first motor 20 and the second motor 26 of this embodiment are so-called motor generators that also have a power generation function, but the first motor 20 has at least a generator (power generation) function for generating reaction force, The electric motor 26 has at least a motor (electric motor) function for outputting a driving force.

  The first planetary gear unit 22 is a single pinion type planetary gear unit that functions as a power distribution mechanism, and supports the first sun gear S1, the first planetary gear P1, and the first planetary gear P1 so as to be capable of rotating and revolving. A first ring gear R1 that meshes with the first sun gear S1 via the one carrier CA1 and the first pinion gear P1 is provided as a rotating element. On the other hand, the second planetary gear unit 24 is a single pinion type planetary gear unit that functions as a speed reducer, and supports the second sun gear S2, the second planetary gear P2, and the second planetary gear P2 so as to be capable of rotating and revolving. A second ring gear R2 that meshes with the second sun gear S2 via the second carrier CA2 and the second pinion gear P2 is provided as a rotating element. The ring gear R1 of the first planetary gear device 22 and the ring gear R2 of the second planetary gear device 24 are integrated compound gears, and an output gear 32 that functions as an output member is provided on the outer periphery thereof. Yes.

  In the first planetary gear device 22, the first carrier CA 1 is connected to the input shaft 18, the first sun gear S 1 is connected to the first electric motor 20, and the first ring gear R 1 is connected to the output gear 32. As a result, the first sun gear S1, the first carrier CA1, and the first ring gear R1 can rotate relative to each other, so that the output of the engine 14 is distributed to the first electric motor 20 and the output gear 32, and the first electric motor. The first electric motor 20 is generated by the output of the engine 14 distributed to 20, and the second electric motor 26 is rotationally driven by the generated electric energy or the stored electric energy. The rotation of the output gear 32 is continuously changed regardless of the predetermined rotation of the engine 14.

  In the second planetary gear unit 24, the second carrier CA2 is coupled to the case 12 which is a non-rotating member, thereby preventing rotation, the second sun gear S2 is coupled to the second electric motor 26, and the second ring gear R2 is It is connected to the output gear 32. Thereby, for example, when the vehicle starts, the second electric motor 26 is driven to rotate, whereby the second sun gear S2 is rotated, and the second planetary gear device 24 decelerates and transmits the rotation to the output gear 32.

  FIG. 2 is a cross-sectional view for explaining the internal structure of the driving apparatus 10 of FIG. The drive device 10 includes an input shaft 18 in a case 12, and a damper 16 connected to the engine and absorbing pulsation due to torque fluctuations of the engine 14 is spline-fitted on an outer peripheral surface on one end side of the input shaft 18. The output of the engine 14 is transmitted to the input shaft 18 through the damper 16. On the other hand, an oil pump drive rotor 34 is connected to the other end side, and lubricating oil is supplied to the gears of the first planetary gear device 22 and the second planetary gear device 24 when the engine 14 is driven. . A first electric motor 20, a first planetary gear device 22, a second planetary gear device 24, and a second electric motor 26 are arranged on the axis of the input shaft 18 in order from the damper 16 side. Here, the input shaft 18 is interposed between the first electric motor 20 and the damper 16, and a ball bearing 28 press-fitted into the inner peripheral edge of the case wall surface 12 a extending from the outer peripheral side of the case 12 toward the inner peripheral side, and Both ends of the input shaft 18 are rotatably supported by ball bearings 30 that are located on the oil pump drive rotor 34 side end of the input shaft 18 and that are press-fitted into the inner peripheral edge of the case wall surface 12b extending from the outer peripheral side of the case 12 toward the inner peripheral side. These ball bearings 28, 30 are subjected to axial thrust load and radial radial load generated by rotation. The input shaft 18 of the present embodiment corresponds to the rotating shaft of the present invention, and the first planetary gear device 22 corresponds to a power distribution mechanism that distributes the power by the planetary gear, and the ball bearings 28 and 30. Corresponds to a pair of ball bearings.

  The first electric motor 20 is disposed between the damper 16 and the first planetary gear device 22. FIG. 3 is an enlarged partial cross-sectional view of the first motor 20 in order to explain the support structure of the first motor 20. The first electric motor 20 supports a first stator 38 composed of a stator coil 38 a and a core 38 b, a first rotor 40 disposed on the inner peripheral side of the first stator 38, and the first rotor 40. A first rotor shaft 42. In addition, the 1st electric motor 20 of a present Example respond | corresponds to the 1st electric motor of this invention.

  The core 38b of the first stator 38 is fixed to the case 12 by bolts 44, and a stator coil 38a is wound around the core 38b. The first rotor shaft 42 is fitted to the input shaft 18 so as to be relatively rotatable, and a cylindrical tube portion 42a in which the first sun gear S1 of the first planetary gear device 22 is provided on an outer peripheral portion on one end side thereof, and A rotor support portion 42c connected to the cylindrical portion 42a via a connection portion 42b and having an outer peripheral portion extending in parallel with the axis is provided. A first sun gear S1 is integrally provided on the outer peripheral portion of the shaft portion of the cylindrical portion 42a on the first planetary gear device 22 side, and the first rotor 40 of the first electric motor 20 and the first planetary gear device 22 are provided. The sun gear is rotated integrally. Further, a case wall 12 c extending from the outer peripheral side of the case 12 to the inner peripheral side is provided between the first electric motor 20 and the first planetary gear device 22, and the case wall 12 c and the first electric motor 20 are connected to each other. A resolver 43 for detecting the rotational speed of the first rotor shaft 42 is disposed therebetween.

  Here, needle bearings 48 and 50 are arranged in a gap formed by a notch provided annularly at both ends of the inner peripheral wall of the cylindrical portion 42a and the outer periphery of the input shaft 18, and the first rotor shaft 42 The input shaft 18 is rotatably supported by needle bearings 48 and 50. Further, a first case wall 12a extending from the outer peripheral side of the case 12 toward the inner peripheral side is provided on the damper 16 side of the first electric motor 20, and an annular shape is provided on the inner peripheral portion of the first case wall 12a. A wall 52 projects from the first case wall 12a. A ball bearing 28 is press-fitted into the inner peripheral surface of the annular wall 52 and receives loads in the radial direction and the axial direction of the input shaft 18. Further, a flange portion 18 a protruding in the radial direction is provided between the first planetary gear device 22 and the second planetary gear device 24 of the input shaft 18. A stepped portion is formed in the flange portion 18a, and a ball bearing 56 is interposed between the stepped portion and the carrier CA2 of the second planetary gear device 24. Note that the needle bearings 48 and 50 of the present embodiment correspond to a pair of roller bearings of the present invention.

  A thrust needle bearing 54 is interposed between the axial end of the annular wall 52 and the connecting portion 42 b of the first rotor shaft 42. Further, a thrust needle bearing 58 is interposed between the flange portion 18a and the cylindrical portion 42a. The first rotor shaft 42 receives a load in the axial direction by the thrust needle bearings 54 and 58. As described above, the first rotor shaft 42 is rotatably supported by the needle bearings 48 and 50 and the thrust needle bearings 54 and 58. The thrust needle bearings 54 and 58 of this embodiment correspond to the thrust roller bearing of the present invention.

  In the first planetary gear device 22, the first sun gear S <b> 1 is connected to the cylindrical portion 42 a of the first rotor shaft 42, and the first carrier CA <b> 1 is connected to the flange portion 18 a of the input shaft 18. Further, as shown in FIG. 2, the first ring gear R1 of the first planetary gear device 22 and the second ring gear R2 of the second planetary gear device 24 are integrally formed, and an output gear 32 is provided on the outer periphery thereof. The composite gear 60 is obtained. The composite gear 60 is rotatably supported by ball bearings 64 and 66 fixed to the case 12, respectively.

  FIG. 4 is a partial cross-sectional view for explaining the second planetary gear unit 24 and the second electric motor 26. The second ring gear R2 of the second planetary gear device 24 is provided in the above-described composite gear 60, and is rotated integrally with the first ring gear R1 of the first planetary gear device 22. The second carrier CA2 is interposed between the second electric motor 26 and the second planetary gear unit 24, and is connected to the case wall 12d extending from the outer peripheral side to the inner peripheral side of the case 12, and the second carrier CA2 Rotation is blocked. The second sun gear S2 is connected to a second rotor shaft 68 of the second electric motor 26, which will be described later, and is rotated integrally with the second rotor shaft 68.

  The second electric motor 26 is disposed between the case wall 12b of the case 12 and the second planetary gear device 24, and includes a second stator 70 including a stator coil 70a and a core 70b, and the second stator 70. And a second rotor shaft 68 that supports the second rotor 72. In addition, the 2nd electric motor 26 of a present Example respond | corresponds to the 2nd electric motor of this invention.

  The core 70b of the second stator 70 is fixed to the case 12 by bolts 74, and a stator coil 70a is wound around the core 70b. The second rotor shaft 68 is fitted to the input shaft 18 so as to be relatively rotatable, and the second sun gear S2 of the second planetary gear device 24 is integrally formed on the outer peripheral portion on one end side thereof. The cylinder part 68a and the rotor support part 68c which is connected with the cylinder part 68a via the connection part 68b and whose outer peripheral part extends in parallel with the shaft center are provided. A resolver 76 for detecting the rotational speed of the second rotor shaft 68 is disposed between the case wall 12 b and the second rotor shaft 68.

  Here, a pair of needle bearings 78 and 80 are disposed in a gap formed by the notch provided annularly at both ends of the inner peripheral wall of the cylindrical portion 68a and the input shaft 18, and the second rotor 68 is disposed in the gap between them. These needle bearings 78 and 80 are rotatably supported by the input shaft 18. The needle bearings 78 and 80 of this embodiment correspond to a pair of roller bearings of the present invention.

  A thrust needle bearing 84 is interposed between the stepped portion 82 provided on the cylindrical portion 68a of the second rotor shaft 68 and the inner peripheral edge portion of the case wall 12d. Further, a thrust needle bearing 88 is interposed between the axial end of the cylindrical portion 68a on the case wall 12b side and the spacer 86 provided on the cylindrical portion 68a side of the ball bearing 30. These thrust needle bearings 84 and 88 receive a load in the axial direction of the second rotor shaft 68. As described above, the second rotor shaft 68 is rotatably supported by the needle bearings 78 and 80 and the thrust needle bearings 84 and 88. The thrust needle bearings 84 and 88 of this embodiment correspond to the thrust roller bearing of the present invention.

  As described above, according to the above-described embodiment, the rotor shafts (42, 68) of the first electric motor 20 and the second electric motor 26 have the both ends of the input shaft 18 rotatably supported by the ball bearings 28, 30. Thrust needle bearings (54, 54) rotatably supported via needle bearings (48, 50, 78, 80) disposed on the outer peripheral surface and disposed at axial ends of the rotor shafts (42, 68). 58, 84, 88). That is, the rotor shaft (42, 68) is supported by the input shaft 18 via a needle bearing (48, 50, 78, 80), and the case 12 via a thrust needle bearing (54, 58, 84, 88). The case walls (12a, 12b, 12d) or the input shaft 18 are supported. Thus, by changing the support mechanism of the rotor shaft (42, 68) from the conventional ball bearing to the needle bearing, the space for mounting the bearing is reduced as a whole, and as a result, the drive device 10 is made compact. Can do.

  Further, according to the above-described embodiment, the first rotor shaft 42 and the first sun gear S1 of the first planetary gear device 20 are integrated with each other by supporting the first rotor shaft 42 with the needle bearings (48, 50). Even if molded, the problem of assembling property such as increasing the inner diameter of the needle bearing (48, 50) does not occur. Thus, by integrally molding, the spline fitting portion between the first rotor shaft 42 and the first sun gear S1 can be eliminated, and the axial length of the drive device 10 can be shortened. Furthermore, by integrally molding, the number of parts can be reduced, and the assembly process can also be reduced.

  Moreover, according to the above-mentioned present Example, since the number of ball bearings can be reduced, the press-in process of a ball bearing can be skipped and an assembly process can be reduced.

  As mentioned above, although the Example of this invention was described in detail based on drawing, this invention is applied also in another aspect.

  For example, in the driving device 10 of the present embodiment, the case walls 12c and 12d of the case 12 are provided. However, the support mechanism of the rotor shaft (42, 68) is changed from a ball bearing to a needle bearing, so that the ball bearing Since the case walls (12c, 12d) for supporting are not required, these case walls (12c, 12d) can be omitted. Thereby, the space for arranging the case wall becomes unnecessary, and the driving device 10 can be made more compact.

  Further, in the driving device 10 of this embodiment, the first planetary gear device 22 that functions as a power distribution mechanism and the second planetary gear device 24 that functions as a speed reducer between the first motor 20 and the second motor 26. Although two planetary gear devices are arranged, the second planetary gear device 24 may be eliminated and only the first planetary gear device 22 as a power distribution mechanism may be arranged.

  The above description is only an embodiment, and the present invention can be implemented in variously modified and improved forms based on the knowledge of those skilled in the art.

1 is a schematic diagram of a vehicle drive device to which the present invention is applied. It is sectional drawing of the vehicle drive device of FIG. It is a fragmentary sectional view explaining the 1st electric motor of FIG. 2, and a 1st planetary gear apparatus. It is a fragmentary sectional view explaining the 2nd electric motor of FIG. 2, and a 2nd planetary gear apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10: Vehicle drive device 12: Housing case 12a, 12b, 12c, 12d: Case wall 14: Engine 18: Input shaft (rotary shaft) 20: 1st electric motor (1st electric motor) 24: 2nd electric motor (2nd 22): First planetary gear device (power distribution mechanism) 28, 30: Ball bearing 40: First rotor 42: First rotor shaft 48, 50, 78, 80: Needle bearing (roller bearing) 54, 58, 84, 88: Thrust needle bearing (thrust roller bearing) 68: Second rotor shaft 72: Second rotor S1: First sun gear (sun gear of power distribution mechanism)

Claims (2)

A rotating shaft having one end connected to the engine, a first electric motor and a second electric motor sequentially disposed on the coaxial axis of the rotating shaft, and the engine interposed between the first electric motor and the second electric motor A vehicle drive device comprising: a power distribution mechanism that distributes the power of the first and second motors by planetary gears;
The rotating shaft is rotatably supported at both ends via a pair of ball bearings fixed to a case wall of a housing case which is a non-rotating member,
A rotor shaft that supports at least one rotor of the first and second electric motors is rotatably supported on the rotating shaft via a roller bearing disposed on an outer periphery of the rotating shaft, and the case wall or An electric motor support mechanism for a vehicle drive device, wherein the rotor shaft is supported in an axial direction by a thrust roller bearing interposed between the rotary shaft and an axial end portion of the rotor shaft. The motor support mechanism for a vehicle drive device according to claim 1, wherein a rotor shaft of the first or second motor is formed integrally with a sun gear of the power distribution mechanism.

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