Patent ID: 8827062

Claim:
A torque transmission unit having a friction clutch and a hydraulic actuation system, comprising: a stepped piston unit including a stepped piston, the stepped piston having a first piston section having a first hydraulically operative effective area that is movable in a first pressure space, and a second piston section having second and third hydraulically operative effective areas that is movable in a second pressure space, wherein the first effective area is smaller than the second effective area, and the first pressure space and a portion of the second pressure space associated with the second effective area are operable to be brought into fluid communication by an overflow line based on a position of the first piston section; and an actuation piston unit including an actuation piston that cooperates with the friction clutch in order to selectively effect an actuation of the torque transmission unit, the actuation piston being associated with a third pressure space that is in fluid communication with the second pressure space via a pressure line, the third pressure space operable to be brought into fluid communication with the portion of the second pressure space associated with the second effective area based on a position of the second piston section via a bypass line.