The compressor has a rotor (2) which is rotatably locate in a stroke ring (1). A second side part (20) of the compressor is attached on a rear side of the stroke ring, while a high pressure chamber (10) is located in a first side part (25). High pressure zones (30a) to (30h) are locate in the stroke ring which open to area side of the ring so that the regions are in direct connection with the high pressure chamber. The first side part has a side block (3) enclosed by a head piece (5). The high pressure chamber is built in the head piece so that it opens in the direction of the stroke ring and forms an opening (39) on the ring side of the head piece.
