JP2007320382A - Driving device for hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress vibrations and noise of a first motor generator in a driving device for a hybrid vehicle. <P>SOLUTION: A rotor core 20 of the first motor generator (a first MG) 12 is shifts in an opposite direction to thrust of a hollow shaft 19 in regard to a stator core 21. When the first MG 12 functions as a generator, electromagnetic suction force is generated in the rotor core 20. The electromagnetic suction force generates in an opposite direction to the shifting direction of the rotor core 20 to the stator core 21, namely the same direction as the thrust. The hollow shaft 19 is pressed against a bearing 23 by the thrust and the electromagnetic suction force. Therefore, the hollow 19 is stable in an axial direction, and the vibrations and noise of the first MG 12 can be suppressed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a drive device for a hybrid vehicle, and more particularly to a structure of a motor generator.

  A hybrid vehicle is a vehicle that is equipped with a drive device having a prime mover with different power sources, such as an engine and an electric motor, and travels by the output of these prime movers.

  Conventionally, various hybrid vehicle drive devices have been proposed. The following Patent Document 1 describes an example of a driving device including an engine, first and second motor generators, and a power distribution and integration device to which these prime movers are connected. The first motor generator mainly functions as a generator and also functions as an engine starter motor. The second motor generator mainly functions as an electric motor, and also functions as a generator when the vehicle is decelerated. The power distribution and integration device includes a planetary gear mechanism, and distributes and integrates power between the engine and the first and second motor generators.

  The engine and the first and second motor generators are connected to three elements of the planetary gear mechanism, that is, the planetary carrier, the sun gear, and the ring gear, and the second motor generator is connected to the drive wheels via the speed reduction mechanism. . By controlling the three prime movers, the drive unit is driven by the first motor generator in a mode in which the second motor generator travels alone, a mode in which the engine and the second motor generator travel in cooperation, or a part of the engine power. It travels in various modes, such as a mode for generating electricity.

  Patent Document 2 below describes that a helical gear is used as a planetary gear used in a drive device for a hybrid vehicle.

JP 2005-212494 A International Publication No. 00/32433 Pamphlet

  Since the planetary gear of the power distribution and integration device uses a helical gear, thrust is generated on the shaft of the first motor generator connected to the power distribution and integration device. For this reason, the drive device has a bearing that can support the shaft in the direction in which the thrust acts.

  However, the thrust fluctuates due to engine rotation fluctuations. Accordingly, the shaft and the rotor core fixed to the shaft fluctuate in the axial direction, and vibration and noise are generated from the first motor generator.

  An object of the present invention is to provide a drive device for a hybrid vehicle that suppresses vibration and noise of a motor generator, particularly a first motor generator that mainly functions as a generator, with a simple structure.

  In order to solve the above-mentioned problems, a drive device for a hybrid vehicle according to the present invention includes a power distribution integration in which an engine, first and second motor generators, and these prime movers are connected to distribute and integrate power among the prime movers. The first motor generator has a rotor core fixed to a shaft connected to the power distribution and integration device, a rotor core facing the rotor core at a predetermined interval, and an exciting coil. The rotor core and the stator core are displaced in the axial direction of the shaft, and an electromagnetic attractive force is generated in the same direction as the thrust force generated on the shaft.

  In the hybrid vehicle drive device, it is preferable that the first motor generator includes an adjustment member that adjusts an axial position of the shaft in order to shift the rotor core in the axial direction with respect to the stator core. is there.

  Further, in the hybrid vehicle drive device, the length of the rotor core in the axial direction is different from the length of the stator core, and the midpoint of the rotor core and the midpoint of the stator core in the axial direction are It is preferable that they are displaced in the axial direction.

  According to the hybrid vehicle drive device of the present invention, it is possible to suppress the noise and vibration of the motor generator, particularly the first motor generator mainly functioning as a generator, with a simple structure.

  Hereinafter, an embodiment of a hybrid vehicle drive device according to the present invention will be described with reference to FIG.

  FIG. 1 is a diagram showing a schematic configuration of a drive device 10 for a hybrid vehicle according to the present embodiment. The drive device 10 shown in FIG. 1 is an example of a device configured to be applied to an FR vehicle, that is, a vehicle in which an engine is mounted on the front portion of the vehicle and the power of the engine is transmitted to the rear drive wheels. The drive device 10 includes an engine 11 that is a prime mover of different power sources, first and second motor generators 12 and 13 having a power generation function, and a power distribution and integration device 14 including a planetary gear mechanism.

  The engine 11 and the first motor generator (hereinafter referred to as the first MG) 12 are connected to two of the three elements of the planetary gear mechanism of the power distribution and integration device 14. That is, the engine 11 is connected to the planetary carrier 16 of the planetary gear mechanism via the engine output shaft 30, the damper device 31 and the input shaft 32, and the first MG 12 is connected to the sun gear 17 of the planetary gear mechanism via the hollow shaft 19. Yes. A drive wheel 37 is connected to the remaining one element of the planetary gear mechanism. That is, the drive wheel 37 is connected to the ring gear 18 of the planetary gear mechanism via the output shaft 33, the differential mechanism 35, and the drive shaft 36. A second motor generator (hereinafter referred to as second MG) 13 is connected to the output shaft 33 via a speed reduction mechanism 15. As a result, the power of each prime mover is integrated by the output shaft 33 and transmitted to the drive wheels 37.

  The drive device 10 travels in various modes. That is, the driving device 10 is a mode in which the engine 11 or the second MG 13 travels, a mode in which the engine 11 and the second MG 13 travel in cooperation, and a mode in which power is generated by the first MG 12 using a part of the power of the engine 11. And so on. In addition, the drive device 10 generates power by the second MG 13 using the kinetic energy of the vehicle input from the drive wheels 37 during deceleration.

  The drive device 10 has an electronic control device (not shown) that controls the operation of the engine 11, the first MG 12, the second MG 13, the power distribution integration device 14, and the like corresponding to various modes. This electronic control device calculates a driver's request output and a battery (not shown) charge request value based on signals from various sensors (not shown). Based on these calculation results, the electronic control device selects various modes and controls the operations of the engine 11, the first MG 12, the second MG 13, the power distribution and integration device 14, and the like.

  1st MG12 is demonstrated using FIG. 1 and FIG. FIG. 2 is a cross-sectional view showing a part of the hybrid vehicle drive device 10 according to the present embodiment.

  The first MG 12 has a rotor core 20 fixed to the hollow shaft 19 and a stator core 21 fixed to the case 24 of the drive device 10 so as to surround the rotor core 20 and wound with an exciting coil 22. The rotor core 20 is opposed to the stator core 21 with a slight gap, and rotates about the axis of the hollow shaft 19. The first MG 12 is a synchronous motor using a permanent magnet, for example. For this reason, the rotor core 20 is provided with a permanent magnet 25.

  The hollow shaft 19 is rotatably supported by a bearing 23 included in the case 24. An input shaft 32 passes through a hole extending in the axial direction of the hollow shaft 19. The input shaft 32 and the hollow shaft 19 are relatively rotatable. A planetary carrier 16 is connected to the tip of the input shaft 32. The planetary carrier 16 is arranged so as to mesh with a sun gear 17 connected to the tip of the hollow shaft 19. That is, the input shaft 32 is connected to the rotor core 20 via the planetary carrier 16, the sun gear 17, and the hollow shaft 19. Thereby, the power of the engine 11 is transmitted to the rotor core 20 via the input shaft 32, the power distribution and integration device 14, and the hollow shaft 19.

  The first MG 12 functions as a generator. When the power of the engine 11 is transmitted to the hollow shaft 19 via the input shaft 32 and the power distribution and integration device 14, the rotor core 20 rotates in synchronization with the hollow shaft 19. A magnetic field is generated by the permanent magnet 25 of the rotor core 20, and an alternating current is generated in the exciting coil 22. The generated electric power is converted into a direct current by an inverter device (not shown) and stored in a battery (not shown). This power is mainly used as driving power for the first MG 12 and the second MG 13.

  Each gear of the planetary gear mechanism of the power distribution and integration device 14 employs a helical gear. For this reason, a force, that is, a thrust is generated in the axial direction during power transmission in the power distribution and integration device 14. When the first MG 12 functions as a generator, thrust is generated in the hollow shaft 19 connected to the sun gear 17. In order to prevent the hollow shaft 19 from moving in the axial direction due to this thrust, for example, a deep groove ball bearing that allows the generated thrust to be used is adopted as the bearing 23. This deep groove ball bearing can receive axial thrust in both directions. When the first MG 12 functions as a generator, the thrust of the hollow shaft 19 is generated from the first MG 12 toward the power distribution and integration device 14 due to the tooth surface shape of each gear of the planetary gear mechanism of the present embodiment. The hollow shaft 19 pressed against the bearing 23 by this thrust is stabilized in the axial direction.

  The first MG 12 mainly functions as a generator driven by the engine 11. At this time, the rotation of the hollow shaft 19 varies in response to the rotation variation of the engine 11. This rotational fluctuation causes a thrust fluctuation when power is transmitted by the helical gear of the power distribution and integration device 14. The hollow shaft 19 vibrates due to the fluctuation of the thrust. In a normal motor generator, this vibration is transmitted to the rotor core 20 and causes vibration and noise. In particular, when the power transmitted to the hollow shaft 19 is small, the size of the thrust may be small with respect to the variation of the thrust. At this time, the hollow shaft 19 does not have a force pressed against the bearing 23 by the thrust, and is likely to vibrate.

  The first MG 12 of this embodiment employs a structure that suppresses vibration and noise. Hereinafter, a characteristic structure of the first MG 12 will be described. A normal motor generator has a structure in which the length of the rotor core and the length of the stator core are equal in the axial direction, and the rotor core and the stator core are aligned and opposed at both ends. With this structure, the rotating motor generator is electromagnetically balanced in the axial direction. That is, no electromagnetic deviation occurs. However, in the present embodiment, the rotor core 20 is displaced with respect to the stator core 21 in the direction opposite to the thrust of the hollow shaft 19 in the axial direction. When the first MG 12 functions as a generator, the thrust of the hollow shaft 19 is generated from the first MG 12 toward the power distribution and integration device 14 as described above. Therefore, the first MG 12 of the present embodiment employs a structure in which the rotor core 20 is shifted to the engine side with respect to the stator core 21.

  As a simple method for shifting the rotor core 20, there is an adjusting means in the axial direction when the drive device 10 is assembled. That is, when the hollow shaft 19 is supported by the bearing 23 and fixed in the axial direction, the shim 26 is inserted between the case 24 and the bearing 23. Thereby, the bearing 23 moves toward the engine 11 side and is attached by moving in the axial direction. That is, the hollow shaft 19 supported by the bearing 23 and the rotor core 20 fixed to the hollow shaft 19 are attached to the engine 11 while moving in the axial direction toward the engine 11 side.

  By adopting this structure, when the first MG 12 functions as a generator, an electromagnetic deviation in the axial direction occurs. For this reason, electromagnetic attraction force is generated in the rotor core 20 in a direction that eliminates the electromagnetic shift. That is, the electromagnetic attractive force is generated in the same direction as the thrust of the hollow shaft 19. Thereby, even if the thrust fluctuates, the hollow shaft 19 is pressed against the bearing 23 by the electromagnetic attractive force and is stabilized in the axial direction. Therefore, vibration and noise of the first MG 12 can be suppressed. The magnitude of the electromagnetic attractive force depends on the position of the rotor core 20, that is, the distance that the rotor core 20 is displaced from the stator core 21. Therefore, it is possible to measure the electromagnetic attraction force corresponding to this deviation distance in advance and adjust the distance that can suppress the vibration and noise of the first MG 12 with the shim 26.

  In the present embodiment, the case where the rotor core 20 is shifted with respect to the stator core 21 by the shim 26 when the drive device 10 is assembled has been described, but the present invention is not limited to this configuration. When the first MG 12 functions as a generator, the first MG 12 may have a structure that generates an electromagnetic shift in the axial direction and generates an electromagnetic attractive force in the same direction as the thrust. For this purpose, the symmetry axis of the rotor core 20 perpendicular to the axial direction may be shifted in the opposite direction to the thrust with respect to the symmetry axis of the stator core 21. Thus, when the first MG 12 functions as a generator, the electromagnetic balance is lost in the axial direction, and an electromagnetic attractive force is generated in the same direction as the thrust. In the present embodiment, the symmetry axis of the rotor core 20 passes through the midpoint of the length of the rotor core 20 in the axial direction, and the symmetry axis of the stator core 21 passes through the midpoint of the length of the stator core 21 in the axial direction. That is, the midpoint of the length of the rotor core 20 only needs to be shifted in the direction opposite to the thrust with respect to the midpoint of the length of the stator core 21. Thereby, even if the length of the rotor core 20 and the length of the stator core 21 in the axial direction are different, the electromagnetic attractive force can be generated in the same direction as the thrust.

  For example, the length of the rotor core 20 in the axial direction is made shorter than the length of the stator core 21 and the engine core ends of the rotor core 20 and the stator core 21 are aligned. As a result, the midpoint of the length of the rotor core 20 in the axial direction is shifted in the opposite direction to the thrust with respect to the midpoint of the length of the stator core 21, and an electromagnetic attractive force can be generated in the same direction as the thrust. Further, the length of the rotor core 20 in the axial direction is made longer than the length of the stator core 21 so that the end portions of the rotor core 20 and the stator core 21 on the power distribution integration device 14 side are aligned. Thereby, the midpoint of the length of the rotor core 20 in the axial direction is shifted in the opposite direction to the thrust with respect to the midpoint of the length of the stator core 21, and an electromagnetic attractive force can be generated in the thrust in the same direction. The configuration in which the midpoint of the length of the rotor core 20 is shifted in the direction opposite to the thrust with respect to the midpoint of the length of the stator core 21 is not limited to the configuration in which the end portions of the rotor core 20 and the stator core 21 are aligned. That is, similarly to the present embodiment, the rotor core 20 may be displaced from the stator core 21 in the direction opposite to the thrust in the axial direction. Regardless of the adjustment by the shim 26, the configuration of the first MG 12 can be easily changed by changing the size in the axial direction of the case 24 accommodating the first MG 12, the position of the bearing 23, and the shape of the hollow shaft 19, for example. A suction force can be generated.

1 is a block diagram showing a schematic configuration of a hybrid vehicle drive device according to the present embodiment. It is sectional drawing which shows a part of drive device of the hybrid vehicle which concerns on this embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Drive apparatus, 11 Engine, 12 1st MG, 13 2nd MG, 14 Power distribution integration apparatus, 16 Planetary carrier, 17 Sun gear, 18 Ring gear, 19 Hollow shaft, 20 Rotor core, 21 Stator core, 32 Input shaft, 33 Output shaft.

Claims (3)

Engine,
First and second motor generators;
A power distribution and integration device that connects these motors and distributes and integrates power between the motors;
In the drive device of the hybrid vehicle having
The first motor generator is
A rotor core fixed to a shaft connected to the power distribution and integration device;
A stator core that is opposed to the rotor core at a predetermined interval and wound with an exciting coil;
Have
The rotor core and the stator core are displaced in the axial direction of the shaft, and an electromagnetic attractive force is generated in the same direction as a thrust force generated in the shaft;
A drive device for a hybrid vehicle. In the hybrid vehicle drive device according to claim 1,
The first motor generator has an adjustment member that adjusts an axial position of the shaft in order to shift the rotor core in the axial direction with respect to the stator core.
A drive device for a hybrid vehicle. In the hybrid vehicle drive device according to claim 1,
The length of the rotor core in the axial direction is different from the length of the stator core,
The midpoint of the rotor core and the midpoint of the stator core in the axial direction are shifted in the axial direction,
A drive device for a hybrid vehicle.

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