Abstract: A rotary vane pump having a metallic rotor, rotatably positioned within an ellipsoidal cavity, a pair of stationary wear plates on the sides of the cavity, the rotor having a plurality of radial slots each of which contain a carbon composite vane riding against the ellipsoidal cavity in reciprocal motion to define variable volume pumping chambers and a pair of carbon composite rotor side plates each being positioned between one side of the rotor and the stationary wear plates, each of the rotor side plates having a similar pattern of congruent radial slots to that of the rotor, the vanes having sufficient width to extend into the slots of both side plates to drive the side plates with the rotor during operating.