Patent ID: 8562318

Claim:
A rotary pump comprising: a. a first rotor comprising a back side, and a front side comprising at least one lobe wherein the number of lobes is N; b. a second rotor comprising a back side, and a front side comprising at least two buckets and at least one lobe, and wherein the number lobes is N±1 resulting in the rotational speed of the first rotor being unequal to the rotational speed of the second rotor; c. wherein the front side of the first rotor is in contact with the front side of the second rotor and operatively configure to rotate relative thereto; d. a housing encompassing the first and second rotors; e. a shaft operatively configured to rotate relative to the housing; f. a first port extending from the front side of the second rotor at each bucket to the back side of the second rotor; g. at least two primary channels provided adjacent the back side of the second rotor and in fluid communication with the first port at specific regions as the second rotor rotates relative to the housing; h. an inlet port provided in the housing, in fluid communication with one of the primary channels; and i. an outlet port provided in the housing, in fluid communication with one of the primary channels other than the primary channel in fluid communication with the inlet port.