Planetary gear transmission systems or components – Input from independent power sources – Including electric motor input
Reexamination Certificate
1999-09-07
2002-01-22
Marmor, Charles A. (Department: 3681)
Planetary gear transmission systems or components
Input from independent power sources
Including electric motor input
C192S111400, C290S00400D, C180S065230
Reexamination Certificate
active
06340339
ABSTRACT:
INCORPORATION BY REFERENCE
The disclosures of Japanese Patent Application Nos. HEI 10-253120 filed on Sep. 7, 1998, HEI 10-253122 filed on Sep. 7, 1998, HEI 10-263623 filed on Sep. 17, 1998 and HEI 10-265514 filed on Sep. 18, 1998 including the specification, drawings and abstract are incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a vehicle drive device provided with at least a motor as the source of driving force for a running vehicle.
2. Description of the Related Art
Recently, there has been an increasing demand for improving the fuel consumption of a motor vehicle and reducing exhaust gas for environmental protection and effective use of resources. To meet the demand, a conventional internal combustion engine is replaced by or used together with a motor. That is, the former corresponds to an electric automobile and the latter corresponds to a hybrid vehicle. An example of the latter is described in Japanese Patent Application Laid-open No. HEI 08-168104.
The device described in HEI 08-168104 is a hybrid drive device having a motor at an engine output side, a torque converter and a transmission mechanism arranged in this order following the motor. This reference is intended to cancel the pulsation of the engine torque by means of the output torque of the motor. With the above structure in which the motor is associated with the engine and the torque converter, it is possible to regenerate and store energy during deceleration and to start or accelerate the vehicle using the electric power. This improves the fuel consumption and reduces exhaust gas emission.
The above device is achieved by adding a motor to a motor vehicle with an automatic transmission gear using an internal engine as a power source. However, motor vehicles have been subjected to downsizing, reduced weight, and increased cabin space. To meet the aforementioned demands, the capacity of the space accommodating the power unit and its attached equipment is considerably limited. Therefore, if the motor is added and installed linearly between the engine and torque converter as stated above, the overall axial length of the drive device or the size of the drive device is increased, thus deteriorating mountability.
In addition, if a motor is arranged adjacent to the torque converter, the torque converter acts as a coupling means for coupling a power source and a transmission such that the motor is coupled to the torque converter. In this case, the torque converter is expanded and contracted in accordance with a variation in the pressure of internal oil (fluid), which requires a structure for allowing the deformation of the torque converter. Also, the motor is required to accurately set and maintain a gap between a stator and a rotor. As the requirements for mechanisms of the torque converter and the motor are contradicting, it is quite a new technical challenge to provide a small, lightweight vehicle as a whole while satisfying such demands. There has been no conventional techniques to address the aforementioned challenge. Installation of the rotor of the motor generator to the front cover of the torque converter has been proposed for reducing the dimension in the axial direction. In such a case, the front cover may expand or contract resulting from variation of pressure applied to the fluid within the torque converter. As a result, the axial position of the rotor of the motor generator installed to the front cover displaces. This may shift the relative position of the thus displaced rotor with respect to the stator of the motor generator fixed to the transmission cover, thus deteriorating output characteristics. Furthermore, if means such as bolts and splines are employed as means for coupling the torque converter and the motor, there is a possibility of deteriorating the productivity of the overall device by increasing the number of mechanically processed parts and the number of assembly steps.
Moreover, if the fluctuation of the torque output from the engine is suppressed by the output torque of the motor, the output side member of the motor is coupled to the output axis of the engine or the output member thereof. The coupled portion of the means for coupling the engine to the motor and torque converter at the output side of the engine is covered with, for example, a casing. A spline axially slid and engaged is, therefore, normally employed.
In the device above, if the engine output side member is coupled to the motor side member by a spline, the rotor, which is a member at the engine output side, has a large angular moment of inertia. Further, due to the presence of a slight gap of the spline in rotational direction, the fluctuation (or pulsation) of the output torque of the engine causes the engine output side member and the rotor to repeated rotate relatively to each other by the small gap. As a result, the spline teeth repeatedly collide with one another in a rotational direction, thereby possibly causing abnormal sound or noise.
SUMMARY OF THE INVENTION
Under these circumstances, the present invention has been made. It is an object of the present invention to provide a vehicle drive device constituted and arranged to meet the mechanical demands while realizing overall downsizing of a hydraulic transmission and a motor.
To attain the above object, a first embodiment of the present invention provides a vehicle drive device comprising a motor including a rotating shaft, a hydraulic transmission provided adjacent the motor in a direction of a rotational center axis and having a shell housing a fluid, a first rotating member extending axially in one direction to said shell, integrally coupled to the shell and a rotating member of the motor and rotatably supported by a bearing member while a movement of the first rotating member to the axial direction is being stopped, and a second rotating member extending to the shell in the axial direction and in a direction opposite to a direction of the first rotating member, integrally coupled to the shell and rotatably supported by a bearing member while an axial movement of the second rotating member is being stopped.
According to the first embodiment, one of the rotating members, integral with the shell of the hydraulic transmission, and the rotating member of the motor are coupled to each other, whereas the other rotating member is rotatably supported by the bearing while the axial movement of the rotating member is stopped. Therefore, the rotating member of the motor is also prevented from moving in the axial direction. This results in the axial position of the rotor that rotates with the rotating member of the motor being fixed. As the axial movement of the rotor of the motor is arrested in the above way, the relative position between the rotor and stator of the motor can be accurately maintained compared with the conventional art in which the rotor of the motor is installed to the outer shell of the fluid gearing.On the other hand, the other rotating member integral with the shell of the hydraulic transmission is rotatably supported by another bearing while axial movement of the other rotating member is allowed. Therefore, if the shell of the hydraulic transmission is deformed due to the fluctuation of the pressure of the internal fluid, the rotating member supported by the other bearing moves axially. Thus, no excessive stress is generated due to the change of pressure. Also, the change of pressure is absorbed by the axial movement of the other rotating member, so that accuracy for supporting the hydraulic transmission and accuracy for the relative positions of the stator and the rotor of the motor can be maintained in a favorable state.
Next, a second embodiment of the present invention provides a vehicle drive device comprising a first housing having an inner peripheral surface, a barrier plate portion protruding radially inward from said inner peripheral surface of said first housing, a second housing to which said first housing is attached, a motor having a stator fixed ont
Amano Masaya
Ibaraki Ryuji
Nagano Shuji
Nakamura Seiji
Tabata Atsushi
Lewis Tisha D.
Marmor Charles A.
Toyota Jidosha & Kabushiki Kaisha
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