Patent ID: 8579617
Filing Date: 2013-11-12
Classification: F04C

Abstract:
1. An oil pump rotor for use in an oil pump including an inner rotor having n external teeth, wherein n is a natural number, an outer rotor having n+1 internal teeth meshing with the external teeth, and a casing forming a suction port for drawing a fluid and a discharge port for discharging the fluid, such that in association with meshing and co-rotation of the inner and outer rotors, the fluid is drawn/discharged to be conveyed according to volume changes of cells formed between teeth faces of the two rotors; wherein, for a tooth profile formed of a mathematical curve and having a tooth addendum circle A a tooth profile of the external teeth of the inner rotor comprises at least either one of a modification, in a radially outer direction, of said tooth profile, on the outer side of said circle D wherein said mathematical curve comprises an envelope of a family of arcs having centers on a trochoid curve defined by Formulas 21 through 26, and relative to said addendum circle A where, X axis: the straight line extending through the center of the inner rotor, Y axis: the straight line perpendicular to the X axis and extending through the center of the inner rotor, (X R R e θ θ (X R where, R θ (X β where, R θ (X β