Abstract: A fuel pump includes an impeller and a cover. The impeller includes a ring portion, which is annular and is placed radially outward of blades. The cover has an arcuate pump flow passage. An enlarged space is formed in a cover side slide surface of the cover. The enlarged space is communicated with the pump flow passage and has an axial gap size, which is axially measured between an axial bottom surface of the enlarged space and an axial end surface of the ring portion and is larger than that of an axial slide gap between the slide surface and the axial end surface of the ring portion.

Abstract: A fuel pump includes a pump part, a motor part, a motor casing, a motor cover, a terminal, and an electric connector part. The terminal is electrically connectable to an external connector for electricity supply. The electric connector part is disposed at an end portion of the motor cover located on the opposite side from a fitted end of the motor cover which is fitted with a housing, and includes a side surface which is slidably in contact with the external connector to determine a fitting position of the electric connector part relative to the external connector, a bottom face from which the terminal rises up, and an opening which is formed on the side surface to communicate between inside and outside of the electric connector part. The bottom face is an inclined surface whose height becomes lower in a direction from generally a center of the motor cover toward the opening.

Abstract: A fuel pump includes an impeller and a cover. The impeller includes a ring portion, which is annular and is placed radially outward of blades. The cover has an arcuate pump flow passage. An enlarged space is formed in a cover side slide surface of the cover. The enlarged space is communicated with the pump flow passage and has an axial gap size, which is axially measured between an axial bottom surface of the enlarged space and an axial end surface of the ring portion and is larger than that of an axial slide gap between the slide surface and the axial end surface of the ring portion.

Abstract: A nozzle holder includes a support portion, which supports a downstream end surface of a planar wall of an injection hole plate. The injection hole plate provided with injection holes is welded to one of the valve body and the nozzle holder. The planar wall may be curved and may be thus convex in an upstream direction toward a downstream end opening such that the planar wall is urged against a peripheral edge of the downstream end opening of the valve body. The planar wall may include a reinforcing rib located radially outward of the injection hole.

Abstract: A nozzle holder includes a support portion, which supports a downstream end surface of a planar wall of an injection hole plate. The injection hole plate provided with injection holes is welded to one of the valve body and the nozzle holder. The planar wall may be curved and may be thus convex in an upstream direction toward a downstream end opening such that the planar wall is urged against a peripheral edge of the downstream end opening of the valve body. The planar wall may include a reinforcing rib located radially outward of the injection hole.

Abstract: A simple and compact fuel supply system which prevents generation of fuel vapor in a delivery pipe of an engine includes a check valve is disposed at a down stream portion of a fuel pressure relieving member or a fuel pressure regulator to seal the fuel delivery pipe when the engine stops so that the pressure in the delivery pipe increases as fuel vapor is generated and, consequently, generation of the fuel vapor is automatically suppressed. Transmission of a pressure wave from the delivery pipe caused while injectors are operating is prevented by the check valve so that harsh noise, which is otherwise caused by resonant vibration of fuel supply pipes and related members, is suppressed.