Transmission decoupling device

摘要

A vehicle transmission, for example a CVT transmission, is provided with a decoupling device between an engine output shaft and a vehicle driveline. The decoupling device in one embodiment includes a clutch assembly which is fixed to a shaft coupled to the transmission output and engageable with a driveline through a piston arrangement. The piston can be urged against the force of a spring by fluid pressure to cause engagement of the clutches of the clutch assembly and thereby to couple engine torque to the vehicle driveline. When fluid pressure is released, the spring urges the piston to a position in which the clutches of the clutch assembly are disengaged, so as to disengage the engine output from the vehicle driveline. In the disengaged state, the vehicle can be towed.