Gear rotor oil pump - has recess in end cover to reduce cavitation and noise

摘要

The hydraulic pump comprises two intermeshing spur gears (1,2) contained in a housing comprising a cylindrical case and two closely fitting end plates. At least one of the end plates has a machined recess bounded by two zones. The gear tip diameters (16,16a) and two lines (13,15) normal to the contact surface (12,14) result in a butterfly form. In a variation, the zones are bounded by chords to the tip diameters forming two isosceles triangles.