Torque transmission device of a four-wheel drive vehicle.

摘要

A torque transmission device of a four-wheel drive vehicle having a pair of drive shafts (100,200) includes a hydraulic pump (3) for transmitting torque to both drive shafts through a variable oil pressure generated therein according to the difference in rotational speed between both drive shafts, and a multiple disc clutch (4) for transmitting torque to both drive shafts by a frictional coupling power. The hydraulic pump has a casing (30) and a rotor (31) housed therein. The casing is rotated by one of the drive shafts (100). The rotor is rotated by the other drive shaft (200) through a transmitting member (7), a cam mechanism (5) and a rotary sleeve (2). The transmitting member has a clutch operating portion for operating the clutch. When the transmitted torque exceeds a predetermined level, the cam mechanism (5) is adapted to move the transmitting member (7) to operate the multiple disc clutch (4) with no intermediary of the casing (30).