Patent attributes
A power transmission mechanism for a vehicle includes a clutch assembly which includes a two-way clutch and an electromagnetic clutch. The two-way clutch includes three rows of rollers retained by a retainer and disposed between a clutch inner member, which is actually a stem of a constant-velocity joint mounted on the outboard end of a drive axle, and a clutch outer member, which is actually a hub ring of a hub bearing supporting a vehicle wheel. Simply by energizing and deenergizing the electromagnet of the electromagnetic clutch, the two-way clutch can be engaged and disengaged. Since the rollers are arranged in three rows, it is possible to increase the contact area between the rollers and the clutch inner and outer members and thus the maximum torque that can be transmitted through the rollers without the need to increase the number of rollers in each row or their length or diameter.