Rotary compressor or expansion engine of hypotrochoidal configuration and angularly displaced gear means

摘要

The rotary compressor or expansion engine of the hypotrochoidal, two-lobe housing cavity type in which a rotor of a triangular profile is supported for planetative rotation within the housing cavity, has the meshing relationship of the timing gears angularly indexed slightly with respect to each other and from the theoretically desired position (where the apex portions of the rotor traces a path parallel to the inner surface of the housing cavity) so that the apex portions trace a path such that the apex portions are in close running-fit with the inner surface of the housing cavity in the area of highest pressure differential across the apex portions of the rotor.