Rotary internal geared pump or motor - has undercut, cylindrical flank rotor teeth meshing with eccentric axis of rotary internal gear ring

摘要

Rotary pump or motor has rotor (5) carried in the housing (3) and an annular disc (7), whose axis is offset relative to that of the rotor and which surrounds the rotor whilst in engagement therewith so that it rotates in the same direction, with spaces between rotor and element acting as working chambers. The rotor has teeth (5a) with undercut roots and cylindrical flanks (5b) acting as pistons in recesses (9) with parallel walls (10) provided in the disc (7). The disc is rotatably carried in the housing, and a sickel-shaped disc (15) is provided between the rotor and the annular disc to seal the area where these are not in engagement. Inlet (13) and outlet ports (14) are provided in the end covers of the unit.