Electric vehicle driving device

1. An electric vehicle driving device comprising:

a first motor;

a second motor;

a transmission device to which power of at least one of the first motor and the second motor is transmitted, the transmission device being able to change a reduction ratio; and

an output member that rotates with power output from the transmission device, wherein

a rotation axis of the first motor, a rotation axis of the second motor, and a rotation axis of the transmission device are arranged in parallel to a rotation axis of the output member, and

when seen from an axial direction parallel to the rotation axis of the output member, a position of the rotation axis of the first motor, a position of the rotation axis of the second motor, a position of the rotation axis of the transmission device, and a position of the rotation axis of the output member differ from each other, and the rotation axis of the first motor is located on one side of a straight line passing through the rotation axis of the output member and the rotation axis of the transmission device and the rotation axis of the second motor is located on the other side of the straight line.

2. The electric vehicle driving device according to claim 1 , comprising a connector for mounting wiring for supplying electric power to the first motor and the second motor, wherein

when seen from the axial direction, the connector is located in a smaller region of two regions partitioned by a first half line passing through the rotation axis of the first motor with the rotation axis of the output member serving as an end point and a second half line passing through the rotation axis of the second motor with the rotation axis of the output member serving as an end point.

3. The electric vehicle driving device according to claim 1 , comprising:

a first reduction gear that amplifies torque generated in the first motor and transmits the torque to the transmission device; and

a second reduction gear that amplifies torque generated in the second motor and transmits the torque to the transmission device.

4. The electric vehicle driving device according to claim 1 , wherein a distance to the rotation axis of the first motor from the straight line and a distance to the rotation axis of the second motor from the straight line are equal to each other.

5. The electric vehicle driving device according to claim 3 , wherein

the first motor includes a first motor gear, and

the first reduction gear is located between the first motor gear and the transmission device.

6. The electric vehicle driving device according to claim 3 , wherein

the second motor includes a second motor gear, and

the second reduction gear is located between the second motor gear and the transmission device.

7. The electric vehicle driving device according to claim 5 , wherein

the first reduction gear includes:

a first gear of the first reduction gear that is engaged with the first motor gear;

a second gear of the first reduction gear that is engaged with the first gear of the first reduction gear; and

a third gear of the first reduction gear that is a gear coaxial with the second gear of the first reduction gear and rotates together with the second gear of the first reduction gear, and

a rotation axis of the first gear of the first reduction gear is located between the rotation axis of the first motor and the rotation axis of the transmission device and a rotation axis of the second gear of the first reduction gear and the third gear of the first reduction gear is located between the rotation axis of the first gear of the first reduction gear and the rotation axis of the transmission device.

8. The electric vehicle driving device according to claim 6 , wherein

the second reduction gear includes:

a first gear of the second reduction gear that is engaged with the second motor gear;

a second gear of the second reduction gear that is engaged with the first gear of the second reduction gear; and

a third gear of the second reduction gear that is a gear coaxial with the second gear of the second reduction gear and rotates together with the second gear of the second reduction gear, and

a rotation axis of the first gear of the second reduction gear is located between the rotation axis of the second motor and the rotation axis of the transmission device and a rotation axis of the second gear of the second reduction gear and the third gear of the second reduction gear is located between the rotation axis of the first gear of the second reduction gear and the rotation axis of the transmission device.

9. The electric vehicle driving device according to claim 1 , wherein

when the first motor includes a first rotor, a first stator, and a first coil, and a plane passing through a first end portion as a portion located on an endmost side in an axial direction parallel to the rotation axis of the first motor among an end portion of the first rotor in the axial direction, an end portion of the first stator in the axial direction, and an end portion of the first coil in the axial direction and being orthogonal to the rotation axis is assumed to be a first plane, and

the second motor includes a second rotor, a second stator, and a second coil, and a plane passing through a second end portion as a portion located on an endmost side on an opposite side to the first end portion in the axial direction among an end portion of the first rotor in the axial direction, an end portion of the first stator in the axial direction, and an end portion of the first coil in the axial direction and being orthogonal to the rotation axis is assumed to be a second plane,

a length of the transmission device in the axial direction is larger than a distance between the first plane and the second plane.

10. The electric vehicle driving device according to claim 1 , wherein

the transmission device includes:

an input gear that receives power of the first motor;

a sun gear shaft that rotates together with the input gear;

a first sun gear that rotates together with the sun gear shaft;

a first pinion gear that is engaged with the first sun gear;

a first carrier that supports the first pinion gear so as to enable the first pinion gear to rotate and enable the first pinion gear to revolve about the first sun gear;

a clutch that restricts rotation of the first carrier; and

a first ring gear that receives power of the second motor as an external gear and is engaged with the first pinion gear as an internal gear, and

the clutch is a one-way clutch.

11. The electric vehicle driving device according to claim 1 , wherein

when the first motor includes a first rotor, a first stator, and a first coil, and a plane passing through a first end portion as a portion located on an endmost side in an axial direction parallel to the rotation axis of the first motor among an end portion of the first rotor in the axial direction, an end portion of the first stator in the axial direction, and an end portion of the first coil in the axial direction and being orthogonal to the rotation axis is assumed to be a first plane, and

the second motor includes a second rotor, a second stator, and a second coil, and a plane passing through a second end portion as a portion located on an endmost side on an opposite side to the first end portion in the axial direction among an end portion of the first rotor in the axial direction, an end portion of the first stator in the axial direction, and an end portion of the first coil in the axial direction and being orthogonal to the rotation axis is assumed to be a second plane,

at least a part of the transmission device is located between the first plane and the second plane.

12. The electric vehicle driving device according to claim 1 , wherein a distance to the rotation axis of the second motor from the straight line is larger than a distance to the rotation axis of the first motor from the straight line.