rotor 3 the length of the segments 10 exceeds the greatest width of the rotor 3 by more than the stroke length of the camshaft 4 in order to guarantee the same free space necessary for axial actuation the extended segments 10 serve the rotor 3 during axial displacement as guide rods on which this glides with the small radial play of the segments 10 in their hydraulic chambers 15 in order to avoid a redundant determination of the mounting of the drive wheel 9 the radial play between the drive wheel 9 and the seal ring carrier 14 as well as between the cylindrical housing 2 and the rotor must be greater than the radial play between segments 10 and the curved walls 16 16 u2032 of the hydraulic chambers 15 radial forces of the drive wheel 9 are consequently not directly transmitted over the segments 10 and the rotor 3 to the sealing ring bearer 14 on the periphery of the rotor 3 for bridging the radial play in relation to the cylindrical housing 2 a sealing ring 21 is arranged through which the same is subdivided into a first and second operating chamber 22 23 for damping the striking noise of the rotor 3 on the bottom 5 an elastic buffer 33 is arranged on the latter the pressurized oil supply to the operating chambers 22 23 takes place through a first 4 3 way proportional valve 24 this takes place through a from connection with a first and a fourth radial groove 25 26 of the sealing ring carrier 14 the first radial groove 25 is connected via four axial.