Patent ID: 8584637

Claim:
A camshaft adjuster for a camshaft which serves to actuate cylinder valves of an internal combustion engine, wherein retardation torques in a direction of retarded cylinder valve opening times are imparted back to the camshaft adjuster by the camshaft when cams are running on, and oppositely directed advance torques in a direction of advanced cylinder valve opening times are imparted back to the camshaft adjuster by the camshaft when cams are running off, the camshaft adjuster comprising: a pressure chamber and an adjusting member arranged in the pressure chamber, the adjusting member divides the pressure chamber into a first chamber part and a second chamber part, wherein pressure medium can be supplied to the first chamber part and the second chamber part and pressure medium can be discharged from the first chamber part and the second chamber part, such that the adjusting member is movable by a pressure difference between the first chamber part and the second chamber part, resulting in a rotation of the camshaft, wherein, when a relatively high pressure prevails in the first chamber part, the camshaft is rotated in a direction of the advanced cylinder valve opening times, and when a relatively high pressure prevails in the second chamber part, the camshaft is rotated in a direction of the retarded cylinder valve opening times, and wherein the supply and discharge of pressure medium is controllable by a control device, a torque mode or a pump mode can be selectively set by the control device, wherein in the torque mode, predominantly camshaft torques are utilized to build up pressure in the first chamber part or in the second chamber part, and in the pump mode, the pressure build-up in the first chamber part or in the second chamber part is realized predominantly by pressure medium provided by a pressure medium pump, wherein the control device comprises a control valve and a rotary transmitter arranged on the camshaft, the pressure medium can be conducted to and discharged from the first chamber part through first orifices in the camshaft, and the pressure medium can be conducted to and discharged from the second chamber part through second orifices in the camshaft, by the control valve and the rotary transmitter, and an orifice cover is arranged in the rotary transmitter such that the first orifices and the second orifices are opened up or blocked as a function of the rotary angle of the camshaft.