A fuel pump includes a mechanical regulating valve arranged in a pump body which modulates the pressure in a high pressure space so that the pressure matches the engine demand. Modulation by the regulating valve requires adjustment of the inlet fuel quantity, adjustment of the volume of the high pressure space, and control of a return fluid communication enabling fuel to exit the high pressure reservoir.

A liquid pump applicable in a fuel system such as a common rail fuel system includes a valve assembly having a valve stack with axially aligned components, dead volume, and vapor-distributing flow channels, for cavitation mitigation. An inlet valve meters a flow of liquid into the pump for pressurization by a plurality of reciprocating plungers operated by way of a rotating camshaft.

A fuel system is disclosed for use with an engine, including a fuel injector assembly fluidly coupled with a low-pressure fuel conduit, an accumulator, and a cap within an opening in the accumulator. The fuel injector assembly may be structured to draw in low-pressure fuel, pressurize the fuel, and store the pressurized fuel in the accumulator for injection to a combustion chamber. The cap has a pressure sensor and a pressure relief valve therein, and drains fuel leaked past fluid seals between the cap and each of the pressure sensor, the pressure relief valve, and the accumulator by way of a common drain line.

In a hybrid fuel supply system for the same high pressure supply pump used for gasoline direct injection (DI) is also used to supply the port injection (PI) system. For a given pumping stroke, fuel can be delivered only to the DI system, only to the PI system, or a first portion can be delivered to the DI system and a second portion delivered to the PI system. The pumping chamber always fills to maximum volume. Fuel metering for DI is by a control valve, which when closed delivers fuel into the DI system and when opened spills pumped fuel into the PI system. Any spill at high pressure opens a pressure regulating valve in the PI system that dumps fuel at excess pressure to a low pressure region to maintain the PI system at a constant target pressure.

A fuel pump includes a mechanical regulating valve arranged in a pump body which modulates the pressure in a high pressure space so that the pressure matches the engine demand. Modulation by the regulating valve requires adjustment of the inlet fuel quantity, adjustment of the volume of the high pressure space, and control of a return fluid communication enabling fuel to exit the high pressure reservoir.

In a hybrid fuel supply system for the same high pressure supply pump used for gasoline direct injection (DI) is also used to supply the port injection (PI) system. For a given pumping stroke, fuel can be delivered only to the DI system, only to the PI system, or a first portion can be delivered to the DI system and a second portion delivered to the PI system. The pumping chamber always fills to maximum volume. Fuel metering for DI is by a control valve, which when closed delivers fuel into the DI system and when opened spills pumped fuel into the PI system. Any spill at high pressure opens a pressure regulating valve in the PI system that dumps fuel at excess pressure to a low pressure region to maintain the PI system at a constant target pressure.

A fuel pump for conveying fuel includes a conveying unit having a cylinder, a plunger received in the cylinder, a pump spring received in the cylinder, an inner sleeve connected to the plunger, an outer sleeve in contact with the pump spring and in contact with a roller of a cam mechanism, and a locking bolt configured to detachably connect the inner and outer sleeves.

A fuel pump includes a pump head defining a barrel in which a plunger is slidable to pressurise fuel in a pumping chamber, and a fluid-inlet path through which fuel flows in to the pumping chamber under control of an inlet valve during a plunger return stroke. The plunger causes pressurisation of the fuel in the fluid-inlet path. The fuel pump may also include a fluid-outlet path through which fuel flows out of the pumping chamber, preferably under control of an outlet valve, during a plunger pumping stroke.

A method and to a device for operating a pressure reservoir, where during a compression phase in a pump chamber, a pump periodically increases the pressure of a fluid located therein, and by means of a discharge valve controlled by differential pressure fluid under high pressure is allowed to be introduced from the pump chamber into the pressure reservoir. During a decompression phase following a compression phase, fluid from a fluid reservoir is introduced into the pump chamber by means of a controllable intake valve. In order to be able also to operate the pressure reservoir without a high pressure measurement directly in the pressure reservoir, the fluid pressure in the pressure reservoir is ascertained by means of a pressure determination in the pump chamber. The pressure determination takes place indirectly, monitoring of the intake valve in the decompression phase.

A liquid pump applicable in a fuel system such as a common rail fuel system includes a valve assembly having a valve stack with axially aligned components, dead volume, and vapor-distributing flow channels, for cavitation mitigation. An inlet valve meters a flow of liquid into the pump for pressurization by a plurality of reciprocating plungers operated by way of a rotating camshaft.