A sealing system of rotary piston machines, the rotor excludes rotor discs which are arranged next to one another, and which are seated on the common rotor axle and are pressed apart from one another by acting spring and/or gas forces in the joints between the discs in such a way that the end sides of the discs which point towards the side walls of the housing bear sealingly against the latter and thus prevent the access of the medium to the axles. Assemblies comprising movable shaped lamellae which adapt to the changing joint widths and prevent an inner flow around the rotor are present in the part joints between the discs.