Patent ID: 7171941

Claim:
A method of conveying fluid through a positive displacement rotary device, comprising: rotating a drive disc on a drive shaft around a drive shaft axis of rotation, the drive disc positioned between coupled first and second chamber halves; rotating at least one drive plate around a drive plate axis of rotation that is ninety degrees and tangent to the drive shaft axis of rotation, the drive plate including at least two drive lobes and the drive plate rotatably engaged to the drive disc with the drive plate axis of rotation located between the drive lobes; sweeping the drive lobes through camming chambers in the first and second chamber halves, each camming chamber in fluid communication with an inlet/outlet port in the chamber half, and the camming chambers shaped to follow the path of the drive lobes as the drive disc rotates on the drive shaft axis of rotation and the at least one drive plate rotates on the drive plate axis of rotation.