Patent ID: 8651843

Claim:
A device for pumping a fluid, the device comprising: a body concentric with a first axis, the body defining a pump chamber having a first open end and an inlet that receives the fluid; a first plate sealingly connected to the body disposed over the first open end, the first plate having an outlet that communicates with the pump chamber; a rotor rotatably supported about a second axis within the pump chamber, wherein the second axis is offset from and parallel to the first axis, the rotor having a first open ended cylindrical portion in contact with a second open ended cylindrical portion to define a central chamber, and wherein the rotor includes a plurality of radially and axially extending slots disposed through the first cylindrical portion and the second cylindrical portion; a plurality of vanes radially slidably disposed within the plurality of slots, the plurality of vanes each having an inner end and an outer end; and a ring disposed freely within the central chamber radially inward of the plurality of vanes, wherein the ring is configured to limit the radial inward movement of the plurality of vanes, and whereby the fluid is pumped from the inlet of the body to the outlet of the first plate as the rotor rotates causing the outer ends of a subset of the plurality of vanes to contact the body and the inner ends of the subset of the plurality of vanes to contact the ring.