To reduce flow resistance of fuel, by effectively using vapor by cavitation, when rotating an impeller; and to reduce the flow resistance of the fuel even in a part of not capturing the vapor, by forming a coating film layer having high fuel fluidity.
This fuel pump is constituted so that the impeller is arranged in a casing having a flow passage inlet for introducing the fuel and a flow passage outlet for delivering the fuel, and a pump flow passage forming a substantially C shape corresponding to a blade groove of an outer peripheral part of the impeller, is formed in the casing, and the fuel introduced to the pump flow passage from the flow passage inlet by rotation of the impeller, is delivered from the flow passage outlet after being boosted in a process of flowing in the pump flow passage, and is characterized in that a fine recess-projection capable of capturing the vapor of the cavitation when rotating the impeller, is formed in at least a part of a pump flow passage surface. A surface of the fine recess-projection is coated with the coating film layer having high fuel fluidity of the film thickness for maintaining a recess-projection shape of this surface.
KATO KOJI
HARA HIROYUKI
