TECHNICAL FIELD

The present disclosure relates to a vehicle drive device that includes an input member drivingly coupled to an internal combustion engine, an output member drivingly coupled to wheels, a transmission provided in a first power transfer path that connects between the input member and the output member, a rotary electric machine that can transfer a drive force to the first power transfer path via a second power transfer path, and a speed reducer provided in the second power transfer path.

BACKGROUND ART

It is conceivable to configure the vehicle drive device described above to be able to transfer the drive force of the rotary electric machine via the second power transfer path to a portion of the first power transfer path on the side of the output member with respect to the transmission, and dispose the speed reducer between the transmission and the rotary electric machine in the axial direction. An example of the thus configured vehicle drive device is illustrated in FIG. 7 of European Patent No. 2542435 (Patent Document 1).

RELATED-ART DOCUMENTS

Patent Documents

Patent Document 1: European Patent No. 2542435

SUMMARY OF THE DISCLOSURE

Problem to be Solved by the Disclosure

In the vehicle drive device described above, it is necessary to support each of the transmission, the speed reducer, and the rotary electric machine, and it is desirable that the rotary electric machine should be supported on both sides in the axial direction, in order to enhance the precision in supporting the rotary electric machine. In consideration of the mountability of the vehicle drive device on a vehicle etc., it is desirable that the axial dimension of the vehicle drive device should be suppressed to be small, even in the case where the transmission, the speed reducer, and the rotary electric machine are arranged side by side in the axial direction, by disposing the speed reducer between the transmission and the rotary electric machine in the axial direction as described above. However, Patent Document 1 does not describe such issues.

Thus, it is desirable to achieve a technique that enables a reduction in the axial dimension of a vehicle drive device while appropriately supporting each rotary member in the case where a speed reducer is disposed between a transmission and a rotary electric machine in the axial direction.

Means for Solving the Problem

The present disclosure provides a vehicle drive device including: an input member drivingly coupled to an internal combustion engine; an output member drivingly coupled to wheels; a transmission provided in a first power transfer path that connects between the input member and the output member to transfer rotation transferred from a side of the input member to a transmission output member with a speed of the rotation varied; a rotary electric machine capable of transferring a drive force via a second power transfer path to a portion of the first power transfer path on a side of the output member with respect to the transmission output member; a speed reducer provided in the second power transfer path to transfer rotation transferred from a side of the rotary electric machine to the side of the output member with a speed of the rotation reduced; and a case, in which: the rotary electric machine and the speed reducer are disposed coaxially with the transmission output member on a first axial side, which is one side in an axial direction, with respect to the transmission; the case includes a first case portion that supports the transmission and the transmission output member, and a second case portion that supports the rotary electric machine; the first case portion includes an end wall portion disposed on the first axial side with respect to the transmission; the second case portion includes a first support portion disposed on the first axial side with respect to a rotor of the rotary electric machine to support a rotor shaft that rotates together with the rotor, and a second support portion disposed on a second axial side, which is opposite to the first axial side in the axial direction, with respect to the rotor to support the rotor shaft; the second support portion includes a bearing attachment portion to which a rotor bearing for supporting the rotor shaft is attached, and a radially extending portion that extends from the bearing attachment portion toward an outer side in a radial direction; and the speed reducer is disposed between the radially extending portion and the end wall portion in the axial direction to face the radially extending portion and the end wall portion in the axial direction.

With this configuration, output torque of the rotary electric machine can be transferred to the output member via the speed reducer. Hence, it is easy to secure a necessary drive force by driving the wheels by transferring, to the output member, rotation of the rotary electric machine after the speed reducer reduces the speed of the rotation, in addition to rotation of the internal combustion engine after the transmission varies the speed of the rotation.

With the configuration described above, the transmission and the transmission output member can be supported by the first case portion, and the rotary electric machine can be supported on both sides in the axial direction by the first support portion and the second support portion of the second case portion. In the configuration described above, the speed reducer is disposed between the radially extending portion of the second case portion and the end wall portion of the first case portion in the axial direction to face the radially extending portion and the end wall portion in the axial direction. Therefore, the speed reducer can be supported using at least one of the second case portion which includes the radially extending portion and the first case portion which includes the end wall portion, even if no wall portion is provided to support the speed reducer, separately from the radially extending portion and the end wall portion. That is, a dedicated support wall for supporting the speed reducer can be removed by causing the radially extending portion or the end wall portion to also serve as a support wall that supports the speed reducer, and it is possible to reduce the axial dimension of the vehicle drive device compared to the case where such a dedicated support wall is provided.

With the configuration described above, it is advantageously easy to reduce the span of support for the rotor shaft by the first support portion and the second support portion, and easy to enhance the precision in supporting the rotor shaft, compared to the case where the speed reducer is disposed between the rotary electric machine and the radially extending portion in the axial direction.

With the configuration described above, as described above, it is possible to reduce the axial dimension of the vehicle drive device while appropriately supporting each rotary member.

Further characteristics and advantages of the vehicle drive device will become clear from the following description of embodiments made with reference to the drawings.

