shows an embodiment of the rotary piston machine in which a pressure on the wall of the annular conduit 1 is absorbed by a claw shaped clip 12 mounted onto the lever 5 it is thus possible for the wall to be significantly thinner for example than it could be without such a clip or for the rotary piston machine to be designed for significantly higher pressure in the gap region oriented toward the two respective adjacent lever surfaces sealing components 13 in particular sealing rings can be advantageously inserted into the projections 14 on both sides in the gap region which projections are encompassed by the clip 12 a short lever 5 is achieved for example if the shaft 7 and the annular conduit 1 abut each other in the gap region and for example a seal is produced in the manner shown in fig5 in another advantageous provision the annular conduits 1 are assembled of two parts such as in the central movement plane of the piston 2 so that the piston 2 and the seals 13 can be used with no trouble in this instance it is also possible for example for a flange to be formed onto the outside of the annular conduits 1 for the clamping of the two shells of the circular cylinder 1 the above describe base unit of the rotary piston machine can be used for various purposes for example as a centralized or decentralized steering drive unit for wheels as a rotary drive unit for wheels as a hydraulic servomotor or in combination as.