Patent ID: 6135730
Filing Date: 2000-10-24
Classification: F02M,F04D,F05B

Abstract:
An electric fuel pump, comprising:an impeller having a vane groove portion at its outer circumferential portion of a discshape;a motor portion for rotation-driving said impeller;a pump casing disposed in opposition to the opposite side surfaces of said impeller with a small gap therebetween to define a sliding surface supporting said impeller, defining an arcuate belt-shaped pump chamber extending along the outer circumferential portion of said impeller around said sliding surface and having a fuel suction port at one end portion of said arcuate bel-shaped chamber and a pump chamber outlet at the other end portion;an abutment relief portion disposed in said pump casing at the inner circumference side of said pump chamber in the vicinity of the side opposing said pump chamber outlet, said abutment relief portion having a gap larger than said small gap;a dam portion of said pump casing, disposed between said pump chamber outlet and said fuel suction port, wherein said abutment relief portion is not provided for at least some of said dam portion; andmeans for creating hydraulic pressure in a direction perpendicular to a rotational direction of said impeller, thereby preventing said impeller from scraping said dam portion, wherein said means comprises an abrupt side wall defined at an end portion downstream of the side of said abutment relief portion opposing said pump chamber outlet.