Fuel pump

Abstract

A fuel pump improved in pump efficiency is provided. An impeller rotating in a pump casing has an approximately disk-shaped configuration with a group of recesses formed in a region extending along the outer peripheries of the obverse and reverse sides of the impeller. The recesses are repeatedly arranged at a distance between each other in the circumferential direction with a partition provided between each pair of adjacent recesses. The radially inner and outer end portions of the partition are positioned on the same radius, and the radially middle portion of the partition is curved rearward in the direction of rotation of the impeller. With this fuel pump, the incidence of separation or vortex formation in the flow of fuel is minimized, and a high pump efficiency can be obtained. It is preferable that the maximum amount of curvature of the partition should be from 0.1 to 1.0 mm, and the curved configuration of the rotation direction forward side of each partition on the obverse and reverse sides should be a circular arc with a radius of from 2.3 to 4.3 mm, and/or the curved configuration of the rotation direction rearward side of each partition should be a circular arc with a radius of from 3.0 to 5.0 mm.

Dependencies are inferred from the claim text.