Patent ID: 7766634
Filing Date: 2010-08-03
Classification: F04C,Y10T

Abstract:
1. A crescent gear pump, comprising: a housing defining a rotor chamber, the housing including a working fluid inlet and a working fluid outlet, each in fluid communication with a portion of the rotor chamber; a rotor set rotatable within the rotor chamber, the rotor set comprising: an outer rotor having a first number of inwardly extending teeth; an inner rotor having a second number of outwardly extending teeth, the second number being at least two less than the first number, the teeth of the inner rotor having a conjugate composite profile of the teeth of the outer rotor; and a crescent inserted between the inner and outer rotors of the rotor set and providing a sealing surface between the teeth thereof to separate the working fluid inlet and working fluid outlet in the rotor chamber, wherein each of said outer rotor teeth has a composite profile which includes a portion adjacent a root of the tooth formed to conform to a circular arc and a portion adjacent a tip of the tooth to conform to a hypocycloid arc.