POWER TRANSMISSION DEVICE

PROBLEM TO BE SOLVED: To provide a power transmission device capable of preventing rapid torque generation. SOLUTION: A clutch as the power transmission device is provided with a piston movable in an axial direction for driving a clutch release fork 40, a cylinder 30 having a space for fitting with the piston, a fluid path 120 for feeding oil to the space or discharging the oil 123 from the space and a flow rate adjusting part 60 for reducing the flow rate of the oil in the fluid path 120 when the clutch is connected after a clutch pedal is stepped more than a predetermined amount. The flow rate adjusting part 60 is provided with a pin 23 arranged for either the piston or the cylinder 30 and a groove 33 arranged for the other one with which the pin 23 engages. The groove 33 has a first groove 31 and a second groove 32. In a state that the first groove 31 is engaged with the pin 23, the piston is rotated for a predetermined angle compared with a state that the second groove 32 is engaged with the pin 23 and the rotated piston reduces the flow rate. COPYRIGHT: (C)2009,JPO&INPIT