Patent ID: 8733305
Filing Date: 2014-05-27
Classification: F01L

Abstract:
1. 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 element arranged in the pressure chamber, wherein the adjusting element divides the pressure chamber into a first chamber part A and a second chamber part B, wherein pressure medium can be supplied to the first chamber part A and the second chamber part B and pressure medium can be discharged from the first chamber part A and second chamber part B, such that the adjusting element is movable by a pressure difference between the first chamber part A and second chamber part B, resulting in a rotation of the camshaft, wherein, when a relatively high pressure prevails in the first chamber part A, the camshaft is rotated in the direction of advanced cylinder valve opening times, and when a relatively high pressure prevails in the second chamber part B, the camshaft is rotated in the direction of retarded cylinder valve opening times, and wherein the supply and discharge of pressure medium is controlled by a control device, the control device includes a control valve which is positioned centrally in the camshaft and has a valve piston that is guidable in a valve housing, the valve housing has an inner sleeve and an outer sleeve which is radially outside and surrounds the inner sleeve, and the inner sleeve is fixed against rotational movement by a rotation prevention element, while the outer sleeve is rotatable, a torque mode or a pump mode is selectively settable by the control device, wherein in the torque mode, predominantly camshaft torques are utilized to build up pressure in the first chamber part A or in the second chamber part B, whereas in the pump mode, the pressure build-up in the first chamber part A or in the second chamber part B is realized predominantly by pressure medium provided by a pressure medium pump P.