Cam shaft phase setter comprising an annular reflux valve

A phase setter for adjusting a rotational angular position of a cam shaft relative to a crankshaft of an internal combustion engine, the phase setter comprising:

• (a) a stator for rotary-driving the phase setter using the crankshaft;
• (b) a rotor configured to rotate relative to the stator about a rotational axis and coupled to the cam shaft so as to drive the cam shaft, and which together with the stator forms a first pressure chamber and a second pressure chamber configured to be charged with a pressure fluid so as to adjust the rotor relative to the stator about the rotational axis;
• (c) a control valve featuring a pressure port, a first working port and a second working port for the pressure fluid;
• (d) a feed for an inflow of the pressure fluid to the pressure port, a first connecting channel for connecting the first pressure chamber to the first working port, and a second connecting channel for connecting the second pressure chamber to the second working port;
• (e) and a reflux valve device which acts in the feed and comprises a valve structure which extends annularly around the rotational axis and the reflux valve device is a constituent of a rotor unit comprising the rotor, and the valve structure comprises one or more axially movable spring tongues or the valve structure is configured to be axially moved so as to restrict a backflow of the pressure fluid through the feed more than the inflow of pressure fluid to the pressure port,
• (f1) wherein the valve structure is positioned in a space between a cylinder defined by the pressure port and a cylinder defined by the second working port, when the pressure fluid is not flowing through the valve structure.