Abstract: The present invention deals with the analytical definition of a tooth profile for rotors used in gear pumps. The purpose is to obtain a pump characterized by noiseless operation, minimization of vibrations and pressure overoscillations generated in operating conditions at the beginning and end of life, and high specific displacement, in such a way to increase the delivery of the pump in given volume conditions. This profile is characterized by an active profile of the tooth flanks with involute stub-tooth with transverse contact ratio (?t) comprised in the range from 0.4 to 0.45, helical teeth with helical contact ratio (??) comprised in the range from 0.6 to 0.85, circular inactive tooth bottom and top profiles, with center (Of, Ot) and radius (rf, rt) defined by a non-dimensional parameter ? in the range from 1.1 to 1.6.

Abstract: The present invention deals with the analytical definition of a tooth profile for rotors used in gear pumps. The purpose is to obtain a pump characterised by noiseless operation, minimisation of vibrations and pressure overoscillations generated in operating conditions at the beginning and end of life, and high specific displacement, in such a way to increase the delivery of the pump in given volume conditions. This profile is characterised by an active profile of the tooth flanks with involute stub-tooth with transverse contact ratio (?t) comprised in the range from 0.4 to 0.45, helical teeth with helical contact ratio (??) comprised in the range from 0.6 to 0.85, circular inactive tooth bottom and top profiles, with centre (Of, Ot) and radius (rf, rt) defined by a non-dimensional parameter ? in the range from 1.1 to 1.6.