초록 ▼

A casing includes a C-shaped casing side pump groove along blades of an impeller. A casing cover also includes a casing cover side pump groove facing the casing side pump groove. The casing side pump groove and the casing cover side pump groove form a pump fluid passage. A gap is provided between an

A casing includes a C-shaped casing side pump groove along blades of an impeller. A casing cover also includes a casing cover side pump groove facing the casing side pump groove. The casing side pump groove and the casing cover side pump groove form a pump fluid passage. A gap is provided between an outer surface of the pump grooves and the impeller. Depth, and outer and inner diameters of a pump groove starts to gradually change from a fuel upstream side of a fuel outlet. The depth of the pump groove gradually decreases, the outer diameter of the pump groove gradually decreases to approach an outer diameter of the impeller, and the inner diameter of the pump groove gradually increases to approach the outer diameter of the impeller. The pump groove ends at a downstream side of the fuel outlet.

대표청구항 ▼

1. A fuel pump comprising:an impeller having a plurality of blades at an outer periphery thereof; and a casing rotatably containing said impeller therein, said casing including a pump groove forming an arc-shaped pump fluid passage along said blades, said casing including a fuel inlet and a fuel out

1. A fuel pump comprising:an impeller having a plurality of blades at an outer periphery thereof; and a casing rotatably containing said impeller therein, said casing including a pump groove forming an arc-shaped pump fluid passage along said blades, said casing including a fuel inlet and a fuel outlet communicating with said pump fluid passage, wherein said impeller rotates to introduce fuel into said pump fluid passage through said fuel inlet and discharge the fuel through the fuel outlet, outer and inner diameters of said pump groove start to gradually change from a fuel upstream side of said fuel outlet, in a rotating direction of said impeller, the gradually changing outer diameter of said pump groove and the gradually changing inner diameter of said pump groove define therebetween a buffer chamber in the pump groove, said pump groove ends at a downstream side of said fuel outlet, and the cross-sectional area of the buffer chamber is gradually decreased from the fuel upstream side of said fuel outlet along the rotating direction of the impeller.