Patent ID: 8327986

Claim:
A combined power transmission and drive unit ( 1 ) for an application in hybrid systems ( 2 ) between at least a first engine ( 3 ) and an element to be driven, with a power transmission device ( 7 ) featuring or forming a start-up element ( 30 ) and an upstream-disposed, selectable clutch device ( 11 ) for selective disconnection/connection of the power flow between the first engine ( 3 ) and the power transmission device ( 7 ), comprising a first clutch part ( 11 E) connectable with the first engine ( 3 ) and a second clutch part ( 11 A) connected with an input (E) of the power transmission device ( 7 ), which can be actuated at least partially by a servo unit ( 12 ) activated hydraulic medium with at least a piston element ( 13 ) and a piston chamber ( 15 ) associated with the piston element ( 13 ) and that can be pressurized with hydraulic medium, wherein the piston chamber ( 15 ) pressurized with the hydraulic medium is disposed and executed such that the hydraulic medium rotates with the rotation speed of the first clutch part ( 11 E) or of an element connected non-rotatably with the first clutch part and wherein between the piston element ( 13 ) and the first clutch part ( 11 E) or an element connected non-rotatably with the first clutch part, a device ( 33 ) for developing a pre-stressing force is disposed.