ROTARY PISTON PUMP, COMPRESSOR OR VACUUM PUMP

Rotary piston pump, compressor or vacuum pump comprising a housing (1), in which a cylindrical hole (11) for a cylindrical rotor (4) is provided, where the rotor (4) comprises an axial opening (41) for a shaft (7) of the pump, compressor or vacuum pump and at least two angularly offset chambers (42) arranged transversely to the rotor (4) axis, where a reciprocating piston (5) is placed in each chamber (42), which, the piston (5), is provided with an opening (53) for a circular cam (8) on the shaft (7) of the pump, compressor or vacuum pump, the shaft (7) being mounted eccentrically to the rotor (4), the housing (1) being provided with removable heads (2) with bearings (21) for the shaft (7) and for tight closing of the cylindrical hole (11) for the rotor (4), and the housing (1) further comprises at least one inlet opening (12) for supplying a medium to the piston (5) chamber (42) and at least one outlet opening (13) for discharging a medium of the piston (5) chamber (42), where the eccentricity of the axis of rotation of the shaft (7) from the axis of the cylindrical rotor (4) is equal to the eccentricity of the axis of the circular cam (8) from the axis of rotation of the shaft (7), where at least one cam (8) is mounted on the shaft (7) removably fixedly.