Patent ID: 8454477

Claim:
A power transmission device having an input shaft connected to an output shaft of a motor, and an output shaft connected to an axle side of a vehicle, wherein power input to the input shaft is transmitted to the output shaft connected to the axle side of the vehicle by switching an engagement state of a clutch of a plurality of clutches, the power transmission device comprising: a mechanical pump that uses power from the motor to generate and deliver a fluid pressure to the clutch; an electromagnetic pump that receives a supply of power to drive, and generates and delivers a fluid pressure to the clutch; an accumulator that is connected to an oil passage that connects the clutch and the electromagnetic pump, and accumulates fluid pressure acting on the clutch and the electromagnetic pump; a switching valve that selectively switches between connecting a mechanical pump side and the clutch in a fluid communicating manner and connecting the electromagnetic pump and the clutch in a fluid communicating manner; a valve drive portion that drives the switching valve so as to connect the mechanical pump side and the clutch when the mechanical pump is driving, and drives the switching valve so as to connect the electromagnetic pump and the clutch when the electromagnetic pump is driving in place of the mechanical pump; a regulator valve that regulates the fluid pressure generated by the mechanical pump to generate a line pressure; and a control unit, wherein when a stoppage control to stop the motor is being performed and before the motor stops, controls the regulator valve so as to increase the fluid pressure from the mechanical pump side acting on the clutch.