Patent ID: 7357722

Claim:
A variable damper transmitting power between a first rotating shaft and a second rotating shaft, comprising, a first plate connected to the first rotating shaft to rotate together with the first rotating shaft; a second plate connected to the second rotating shaft to rotate together with the second rotating shaft as an integral body; a damper spring transmitting power between the first and second plates by being pressed by relative rotation between the first and second plates; and a friction regulating means for variably regulating a frictional force between the first plate and the second plate, wherein the friction regulating means comprises: a solenoid unit operating as an electromagnet and selectively being in either an “on” or an “off” state; and a friction forming means for forming a frictional force between the first plate and the second plate, said frictional force varying according to the state of the solenoid unit, wherein the friction forming means comprises: a pressure plate having a slanted surface; a friction plate disposed between the pressure plate and the second plate to contact the second plate; a wedge contacting the pressure plate and movable along the slanted surface according to the state of the solenoid unit; and an elastic member elastically supporting the wedge toward the pressure plate and the first plate.