Patent ID: 8733308

Claim:
A hydraulically actuated camshaft adjusting device for changing a relative angular position of a camshaft in relation to a crankshaft of an internal combustion engine, the camshaft adjusting device comprising at least first and second hydraulic chambers (A, B), which are arranged between a stator and a rotor and are separated by a vane, and which are supplied with pressurized oil from a pressurized oil source (P) by a hydraulic oil control assembly, the hydraulic oil control assembly includes: a first supply line, which is arranged between the pressurized oil source (P) and the first hydraulic chamber (A), a first check valve is arranged in the first supply line, which permits a flow of hydraulic oil from the pressurized oil source (P) into the first hydraulic chamber (A) and prevents the flow in an opposite direction, wherein the first supply line is free of further switchable valve elements, and the first supply line is the only feed line for hydraulic oil from the pressurized oil source (P) into the first hydraulic chamber (A), a second supply line, which is arranged between the pressurized oil source (P) and the second hydraulic chamber (B), a second check valve is arranged in the second supply line, which permits a flow of hydraulic oil from the pressurized oil source (P) into the second hydraulic chamber (B) and prevents the flow in an opposite direction, the second supply line is free of further switchable valve elements and the second supply line is the only feed line for hydraulic oil from the pressurized oil source (P) into the second hydraulic chamber (B), a valve element, which is arranged to act between the hydraulic chambers (A, B) and a tank (T) and has first, second, and third valve positions (I, II, III), as follows: a) the first valve position (I), in which drainage of hydraulic oil from the first and second hydraulic chambers (A, B) into the tank (T) is interrupted, b) the second valve position (II), in which drainage of hydraulic oil from the first hydraulic chamber (A) to the tank (T) is released and drainage of hydraulic oil from the second hydraulic chamber (B) to the tank (T) is interrupted, and c) the third valve position (III), in which drainage of hydraulic oil from the second hydraulic chamber (B) to the tank (T) is released and drainage of hydraulic oil from the first hydraulic chamber (A) to the tank (T) is interrupted.