CAVITATION NOISE REDUCTION TYPE POSITIVE DISPLACEMENT FUEL PUMP

PROBLEM TO BE SOLVED: To effectively reduce cavitation noise by providing a fuel pump having gear rotors with a plurality of outlet ports spaced apart from each other, a valve on each outlet port, and preventing contraflow of fuel on a downstream side of the outlet port to a low pressure part. SOLUTION: A positive displacement fuel pump assembly 12 adopting a motor as a driving source has an inlet port plate 40 formed with an inlet port 62 and a center penetration bore 64 for housing a mounting shaft, and a cam ring 42 fixed to the inlet port plate 40. The pump is also provided with an external gear rotor 44 rotating inside a bore 68 of the cam ring 42, an internal gear rotor 46 meshed with the rotor 44 and eccentrically rotated and an outlet port plate 48 having a plurality of outlet ports 14 spaced apart from each other. Each outlet port 14 is provided with a valve having a seal ring 50 and a seal support plate 52, to prevent fuel of outlet pressure on a downstream side of the outlet port 14 from returning to a low pressure part.