Patent ID: 6837675
Filing Date: 2005-01-04
Classification: F04D

Abstract:
1. A fuel pump comprising: an impeller having an approximately disk-shaped configuration with a plurality of blade grooves formed serially in a region extending along outer peripheries of obverse and reverse sides of the impeller, wherein an outer peripheral surface of said impeller is a circumferential surface, said impeller being rotated by driving means; and a pump casing having a circumferentially extending recess for forming a circumferentially extending flow passage groove between the same and the blade grooves of said impeller, said pump casing further having a suction opening communicating with an upstream end of said recess and a discharge opening communicating with a downstream end of said recess, said pump casing further having a circumferential wall forming an inner peripheral surface facing the outer peripheral surface of said impeller; wherein a clearance between the outer peripheral surface of said impeller and the inner peripheral surface of said pump casing is relatively small in a region where a flow passage groove pressure is high, said clearance is relatively large in a region where the flow passage groove pressure is low, and a rotation center of said impeller is offset from a center of the inner peripheral surface of said pump casing.