Electric vehicle

1. An electric vehicle, comprising:

a power unit including a motor and a speed reduction device coupled to a motor output shaft, wherein

the speed reduction device having gear trains of two systems respectively forming a drive-power transmission path to transmit rotation of the motor to an output rotation member, and a regenerative-power transmission path to transmit rotation of the output rotation member to the motor, the speed reduction device including

a drive-side one-way clutch provided in the drive-power transmission path at a portion between a drive-side final-stage gear and the output rotation member, and configured to transmit rotation of the drive-side final-stage gear to the output rotation member; and

a regeneration-side one-way clutch provided in the regenerative-power transmission path at a portion between the output rotation member and a regeneration-side first-stage gear and configured to transmit rotation of the output rotation member to the regeneration-side first-stage gear, wherein

gears among pluralities of gears respectively forming the gear trains of the two systems are disposed on a common shaft in such a way as to rotate together,

wherein the drive-side final-stage gear and the regeneration-side first-stage gear are separate from each other, and

wherein the drive-side final-stage gear and the regeneration-side first-stage gear are configured to operate independently of each other.

2. An electric vehicle, comprising:

a power unit including a motor and a speed reduction device coupled to a motor output shaft, wherein

the speed reduction device having gear trains of two systems respectively forming a drive-power transmission path to transmit rotation of the motor to an output rotation member, and a regenerative-power transmission path to transmit rotation of the output rotation member to the motor, the speed reduction device including

a drive-side one-way clutch provided in the drive-power transmission path at a portion between a drive-side final-stage gear and the output rotation member, and configured to transmit rotation of the drive-side final-stage gear to the output rotation member; and

a regeneration-side one-way clutch provided in the regenerative-power transmission path at a portion between the output rotation member and a regeneration-side first-stage gear and configured to transmit rotation of the output rotation member to the regeneration-side first-stage gear, wherein

gears among pluralities of gears respectively forming the gear trains of the two systems are disposed on a common shaft in such a way as to rotate together,

wherein the power unit is provided in a wheel hub forming the output rotation member,

wherein the gear trains include

a sun gear disposed on the motor output shaft,

a planetary gear including a large-gear portion meshing with the sun gear and a small-gear portion configured to rotate together with the large-gear portion,

a drive-side internal gear forming the drive-side final-stage gear and meshing with the small-gear portion, the gear trains also including

a regeneration-side internal gear forming the regeneration-side first-stage gear and meshing with the large-gear portion, wherein

the drive-side one-way clutch is disposed between the drive-side internal gear and the wheel hub, and wherein

the regeneration-side one-way clutch is disposed between the regeneration-side internal gear and the wheel hub.

3. The electric vehicle according to claim 2 , wherein the drive-side internal gear is smaller in diameter than the regeneration-side internal gear.

4. The electric vehicle according to claim 2 , wherein the planetary gear is supported on a carrier fastened to a stator of the motor.

5. The electric vehicle according to claim 2 , wherein the wheel hub includes a first hub part located on one lateral side of a vehicle body and a second hub part located on another lateral side of the vehicle body and connected to the first hub part.

6. The electric vehicle according to claim 5 , wherein the drive-side internal gear is supported on the second hub part, and the regeneration-side internal gear is supported on the first hub part.

7. The electric vehicle according to claim 6 , further comprising:

a drive-side-internal-gear supporting member supporting an outer periphery of the drive-side internal gear; and

a regeneration-side-internal-gear supporting member supporting an outer periphery of the regeneration-side internal gear,

wherein the drive-side-internal-gear supporting member and the regeneration-side-internal-gear supporting member are fastened to an inner periphery of the wheel hub.

8. The electric vehicle according to claim 7 , wherein

the drive-side-internal-gear supporting member is disposed inside the wheel hub and fastened to the wheel hub with a fastening member inserted to the wheel hub from inside, and

the regeneration-side-internal-gear supporting member is located inside the wheel hub and fastened to the wheel hub with a fastening member inserted to the wheel hub from outside.

9. The electric vehicle according to claim 7 , wherein

the first hub part includes a large-diameter portion and a small-diameter portion,

the regeneration-side-internal-gear supporting member is disposed on an inner surface of a wall portion of the wheel hub extending in a radial direction thereof and connecting the large-diameter portion and the small-diameter portion, and wherein

the fastening member penetrates the wall portion from an outer surface thereof and is joined to the regeneration-side-internal-gear supporting member.

10. An electric vehicle having a power unit including a motor and a speed reduction device coupled to a motor output shaft, wherein the speed reduction device has gear trains of two systems are respectively forming a drive-power transmission path to transmit rotation of the motor to an output rotation member, and a regenerative-power transmission path to transmit rotation of the output rotation member to the motor, the speed reduction device comprising:

drive-side clutch means for transmitting rotation of a drive-side final-stage gear to the output rotation member, said drive-side clutch means being disposed in the drive-power transmission path between the drive-side final stage gear and the output rotation member; and

regeneration-side clutch means for transmitting rotation of the output rotation member to a regeneration-side first-stage gear, said regeneration-side clutch means being disposed in the regenerative-power transmission path between the output rotation member and the regeneration-side first-stage gear, wherein

gear means for transmitting rotational power respectively form the gear trains of the two systems, said gear means being disposed on a common shaft so as to rotate together,

wherein the drive-side final-stage gear and the regeneration-side first-stage gear are separate from each other, and

wherein the drive-side final-stage gear and the regeneration-side first-stage gear are configured to operate independently of each other.

11. An electric vehicle having a power unit including a motor and a speed reduction device coupled to a motor output shaft, wherein the speed reduction device has gear trains of two systems are respectively forming a drive-power transmission path to transmit rotation of the motor to an output rotation member, and a regenerative-power transmission path to transmit rotation of the output rotation member to the motor, the speed reduction device comprising:

drive-side clutch means for transmitting rotation of a drive-side final-stage gear to the output rotation member, said drive-side clutch means being disposed in the drive-power transmission path between the drive-side final stage gear and the output rotation member; and

regeneration-side clutch means for transmitting rotation of the output rotation member to a regeneration-side first-stage gear, said regeneration-side clutch means being disposed in the regenerative-power transmission path between the output rotation member and the regeneration-side first-stage gear, wherein

gear means for transmitting rotational power respectively form the gear trains of the two systems, said gear means being disposed on a common shaft so as to rotate together,

wherein the power unit is disposed in a wheel hub forming the output rotation member, and wherein the gear means comprises:

a sun gear disposed on the motor output shaft;

a planetary gear including a large-gear portion meshing with the sun gear and a small-gear portion configured to rotate together with the large-gear portion;

a drive-side internal gear forming the drive-side final stage gear and meshing with the small-gear portion; and

a regeneration-side internal gear forming the regeneration-side first-stage gear and meshing with the large-gear portion, wherein

the drive-side clutch means is disposed between the drive-side internal gear and the wheel hub, and wherein the regeneration-side clutch means is disposed between the regeneration-side internal gear and the wheel hub.

12. The electric vehicle according to claim 11 , wherein the drive-side internal gear is smaller in diameter than the regeneration-side internal gear.

13. The electric vehicle according to claim 11 , wherein the planetary gear is supported on a carrier fastened to a stator of the motor.

14. The electric vehicle according to claim 11 , wherein the wheel hub includes a first hub part disposed on one lateral side of a vehicle body and a second hub part disposed on another lateral side of the vehicle body, and connected to the first hub part.

15. The electric vehicle according to claim 14 , wherein the drive-side internal gear is supported on the second hub part, and the regeneration-side internal gear is supported on the first hub part.

16. The electric vehicle according to claim 15 , further comprising:

drive-side internal-gear supporting means for supporting an outer periphery of the drive-side internal gear; and

regeneration-side-internal-gear supporting means for supporting an outer periphery of the regeneration-side internal gear,

wherein the drive-side-internal-gear supporting means and the regeneration-side internal-gear supporting means are connected to an inner periphery of the wheel hub.