Abstract: A rotary pump apparatus with plural abutting pumping segments has a wafer-like housing with an inner elliptical pumping chamber with intake and discharge ports for a fluid flow. A plurality of identical fluid moving cylindrical segments are movably disposed within the pumping chamber in such a manner that each of the segments abuts at least two other segments within the chamber.The segments rotate in a circular rotary fashion urging the fluid flow between the intake and discharge ports.The apparatus is also provided with a rotor plate rotatably mounted on the housing and a central driven shaft fixedly attached to one surface of the rotor plate. The rotor plate has a series of drive pegs disposed on the surface opposite to that where the shaft is attached.