Patent ID: 7222597

Claim:
A hydraulic device for adjusting a rotation angle of a camshaft relative to a crankshaft of an internal combustion engine, the device comprising: a rotor having a periphery and blades arranged around the rotor periphery and projecting outwardly, the rotor connectable in a rotationally secure manner to the camshaft; a stator connectable in a rotationally secure manner to a drive wheel driven by the crankshaft, the rotor being relatively rotatable with respect to the stator; and a first pressure chamber and a second pressure chamber provided respectively on both circumferential sides of each blade; a hydraulic fluid system having at least one hydraulic valve and being connected to the first and second pressure chambers which are selectively pressurized or depressurized with hydraulic fluid through hydraulic fluid lines; and a volume accumulator being located in a location selected from the group consisting of the device and between the hydraulic valve and a remainder of the device other than the hydraulic valve and the volume accumulator, the hydraulic fluid system and the volume accumulator being operable such that a volume of hydraulic fluid in the volume accumulator is at all times solely determined by pressure in the hydraulic fluid system.