Patent ID: 8360220

Claim:
A power transmission device installed in a vehicle, comprising: a clutch that transmits power from a motor to an axle; a first pump that is driven by power from the motor to generate and output fluid pressure; a second pump that receives and is driven by a supply of electric power to generate and output fluid pressure; a pressure regulating valve that functions as a linear solenoid valve and is formed with an input port, an output port that is connected to the clutch, and a drain port; a switching valve that switches between a first connection state, wherein when the first pump is driving, operation fluid output from the first pump is supplied to the input port of the pressure regulating valve and a supply of operation fluid from the second pump to the input port of the pressure regulating valve is cut off, and a second connection state wherein, when the first pump is not driving, the supply of operation fluid from the first pump to the input port of the pressure regulating valve is cut off and operation fluid output from the second pump is supplied to the input port of the pressure regulating valve; and a bypass valve that supplies operation fluid output from the first pump to the input port of the pressure regulating valve without going through the switching valve.