Vehicle drive device, and front-and-rear wheel-driven vehicle formed of the device

1. A vehicle drive device for distributing the drive power from secondary drive means to right and left drive wheels through drive shafts extending in an axial direction from a differential gear, wherein the drive device uses a clutch to make intermittent the drive power transmission from the secondary drive means to the differential gear, wherein the clutch is arranged coaxially of the differential gear and is axially located at one side relative to the differential gear.

2. The vehicle drive device as set forth in claim 1 , wherein the clutch is an electromagnetic clutch of self-locking type and is composed of an annular outer member, an electromagnetic coil contained in a body of the outer member, an armature arranged outside of the outer member and frictionally engageable with the outer side of the outer member by being attracted when electric current is applied to the electromagnetic coil, an inner member located inside of the inner circumference of the outer member coaxially of the same, and a cam mechanism located between the inner member and the armature for coupling these members with each other when operated, wherein the outer member is connected to a transmission member for the drive power output from the electric motor, wherein the inner member is connected to a differential case which is a component of the differential gear, and wherein the cam mechanism makes a first cam member with the armature and a second cam member with a part of the differential case and is constituted by interposing cam followers between the both cam members.

3. The vehicle drive device as set forth in claim 1 , wherein the vehicle drive device constitutes a front-and-rear drive vehicle provided with prime drive means for driving prime drive wheels and the secondary drive means for driving secondary drive wheels and wherein the vehicle drive device is utilized as the prime drive means or the secondary drive means.

4. A vehicle drive device for distributing the drive power from secondary drive means to right and left drive wheels through drive shafts extending in an axial direction from a differential gear, wherein the drive device uses a clutch to make intermittent the drive power transmission from the secondary drive means to the differential gear, wherein the clutch has a self-locking function and is arranged coaxially of the differential gear and is axially located at one side relative to the differential gear.

5. The vehicle drive device as set forth in claim 4 , wherein the clutch is an electromagnetic clutch of self-locking type and is composed of an annular outer member, an electromagnetic coil contained in a body of the outer member, an armature arranged outside of the outer member and frictionally engageable with the outer side of the outer member by being attracted when electric current is applied to the electromagnetic coil, an inner member located inside of the inner circumference of the outer member coaxially of the same, and a cam mechanism located between the inner member and the armature for coupling these members with each other when operated, wherein the outer member is connected to a transmission member for the drive power output from the electric motor, wherein the inner member is connected to a differential case which is a component of the differential gear, and wherein the cam mechanism makes a first cam member with the armature and a second cam member with a part of the differential case and is constituted by interposing cam followers between the both cam members.

6. The vehicle drive device as set forth in claim 4 , wherein the vehicle drive device constitutes a front-and-rear drive vehicle provided with prime drive means for driving prime drive wheels and the secondary drive means for driving secondary drive wheels and wherein the vehicle drive device is utilized as the prime drive means or the secondary drive means.

7. A vehicle drive device for distributing the drive power from secondary drive means to right and left drive wheels through drive shafts extending in an axial direction from a differential gear, wherein the drive device uses a clutch to make intermittent the drive power transmission from the secondary drive means to the differential gear, wherein the clutch is arranged coaxially of the differential gear and is axially located at one side relative to the differential gear and is constituted by a two-way clutch.

8. The vehicle drive device as set forth in claim 7 , wherein the clutch is controlled into the coupling state for the vehicle traveling direction by driving the secondary drive means in the vehicle traveling direction.

9. A vehicle drive device for distributing the drive power from secondary drive means to right and left drive wheels through a differential gear wherein the drive device uses a clutch to make intermittent the drive power transmission from the secondary drive means to the differential gear, wherein the clutch has a self-locking function,

wherein the clutch is an electromagnetic clutch of self-locking type and is composed of an annular outer member, an electromagnetic coil contained in a body of the outer member, an armature arranged outside of the outer member and frictionally engageable with the outer side of the outer member by being attracted when electric current is applied to the electromagnetic coil, an inner member located inside of the inner circumference of the outer member coaxially of the same, and a cam mechanism located between the inner member and the armature for coupling these members with each other when operated, wherein the outer member is connected to a transmission member for the drive power output from the electric motor, wherein the inner member is connected to a differential case which is a component of the differential gear, and wherein the cam mechanism makes a first cam member with the armature and a second cam member with a part of the differential case and is constituted by interposing cam followers between the both cam members.