In at least some implementations, a method of forming a diaphragm for a liquid pump, includes clamping a substantially planar piece of material about a periphery, and plastically deforming the piece of material inboard of the clamped periphery. In at least some implementations, the material is plastically deformed by pressing a forming member against the material, or the material is plastically deformed by applying a fluid under pressure against the material.

In at least some implementations, a method of forming a diaphragm for a liquid pump, includes clamping a substantially planar piece of material about a periphery, and plastically deforming the piece of material inboard of the clamped periphery. In at least some implementations, the material is plastically deformed by pressing a forming member against the material, or the material is plastically deformed by applying a fluid under pressure against the material.

A fuel booster system having a fuel inlet port, a fuel outlet port, and a fuel accumulator fluidically coupled to both ports. The fuel inlet port allows fuel to be delivered to the fuel accumulator and the fuel outlet port is in fluid communication with a combustion engine to deliver fuel from the fuel booster system to the combustion engine. A source of pressurized gas is also fluidically coupled to the fuel accumulator to deliver pressurized gas through a gas port in one end of the fuel accumulator. A piston is located within the fuel accumulator and the source of pressurized gas can be discharged into the fuel accumulator to force accumulated fuel from the fuel accumulator and to the engine when the fuel booster system determines that the engine needs more fuel.

In at least some implementations, a carburetor includes a body, a fuel pump diaphragm and a pressure pulse passage. The fuel pump diaphragm is carried by the body and defines in part a fuel chamber on one side of the fuel pump diaphragm and a pressure pulse chamber on the other side of the fuel pump diaphragm. The pressure pulse passage communicates the pressure pulse chamber with a pressure pulse source to provide pressure pulses in the pressure pulse chamber to actuate the fuel pump diaphragm. The pressure pulse passage includes an inlet communicating with a passage in which pressure pulses are present and the inlet is spaced from a surface defining the passage in which pressure pulses are present.

In at least some implementations, a carburetor includes a body, a fuel pump diaphragm and a pressure pulse passage. The fuel pump diaphragm is carried by the body and defines in part a fuel chamber on one side of the fuel pump diaphragm and a pressure pulse chamber on the other side of the fuel pump diaphragm. The pressure pulse passage communicates the pressure pulse chamber with a pressure pulse source to provide pressure pulses in the pressure pulse chamber to actuate the fuel pump diaphragm. The pressure pulse passage includes an inlet communicating with a passage in which pressure pulses are present and the inlet is spaced from a surface defining the passage in which pressure pulses are present.

A fuel supply device includes a fuel pump, a filter case, a fuel passage, a discharge passage, and a residual pressure holding valve. A communication port opens at a shifted position of the fuel passage that is positionally shifted from the residual pressure holding valve toward the discharge passage. The fuel passage includes an outside passage part through which fuel flows from the communication port toward the discharge passage, and an inside passage part that throttles a flow of fuel flowing from the communication port toward the residual pressure holding valve more than the outside passage part. When a passage cross-sectional area of the inside passage part is converted into a passage cross-sectional area of a circular pipe, D which is a passage diameter of the circular pipe, and L which is a length of the inside passage part satisfy a relational expression of L/D≧3.

A fuel supply device includes a fuel pump, a filter case, a fuel passage, a discharge passage, and a residual pressure holding valve. A communication port opens at a shifted position of the fuel passage that is positionally shifted from the residual pressure holding valve toward the discharge passage. The fuel passage includes an outside passage part through which fuel flows from the communication port toward the discharge passage, and an inside passage part that throttles a flow of fuel flowing from the communication port toward the residual pressure holding valve more than the outside passage part. When a passage cross-sectional area of the inside passage part is converted into a passage cross-sectional area of a circular pipe, D which is a passage diameter of the circular pipe, and L which is a length of the inside passage part satisfy a relational expression of L/D≧3.

A fuel booster system having a fuel inlet port, a fuel outlet port, and a fuel accumulator fluidically coupled to both ports. The fuel inlet port allows fuel to be delivered to the fuel accumulator and the fuel outlet port is in fluid communication with a combustion engine to deliver fuel from the fuel booster system to the combustion engine. A source of pressurized gas is also fluidically coupled to the fuel accumulator to deliver pressurized gas through a gas port in one end of the fuel accumulator. A piston is located within the fuel accumulator and the source of pressurized gas can be discharged into the fuel accumulator to force accumulated fuel from the fuel accumulator and to the engine when the fuel booster system determines that the engine needs more fuel.

In at least some implementations, an assembly includes a reservoir, a primary fuel pump having an inlet in communication with the reservoir's internal volume, an outlet, a motor and a pumping element driven by the motor and a secondary fuel pump with a body having first and second inlets and an outlet. The first inlet receives fuel from the primary fuel pump and a nozzle is communicated with the first inlet and fuel flows out of the nozzle into the body via the first inlet. The second inlet is in communication with the reservoir inlet, and the outlet is in communication with the internal volume. The flow of fuel through the nozzle draws fuel from the fuel source through the second fuel inlet and that fuel is combined with the flow of fuel from the nozzle and discharged into the reservoir.

A pump apparatus includes: a rotational shaft; a hub portion mounted to the rotational shaft; a centrifugal pump vane mounted to a circumferential surface of the hub portion; an annular disc portion mounted to a tip end of the centrifugal pump vane; and an axial turbine blade mounted to an outer circumferential surface of the annular disc portion. A liquid flow passage through which a liquid flowing from a first side toward a second side in an axis direction of the rotational shaft flows into the centrifugal pump vane is formed at a radially inner side of the annular disc portion, and a gas flow passage through which a gas flowing from the second side toward the first side passes through the axial turbine blade is formed at a radially outer side of the annular disc portion.