An inlet valve for a fluid pump includes a movably supported tappet for closing a fluid inlet opening and an actuator for moving the tappet, wherein the actuator and the tappet are formed separately from each other and can be coupled to one another by a coupling element for transmitting an actuator driving force to the tappet. An assembly method for such an inlet valve is also disclosed.

A method and apparatus for controlling a solenoid actuated inlet valve to a pump chamber of a piston pump. A control circuit energizes the solenoid to open the inlet valve in synchronism with the reciprocation of the piston and thereafter de-energize the solenoid to initiate closure of the inlet valve. The inlet valve is decelerated following de-energization of the solenoid thus effectively reducing engine noise attributable to the inlet valve.

An inlet valve arrangement for a pump head of a fuel pump for use in a common rail fuel injection system comprises an inlet valve member moveable between open and closed positions to control the flow from a source of low-pressure fuel to a pumping chamber of the fuel pump. The inlet valve member is arranged to open in response to the pressure difference between the fluid pressure of fuel on an inlet side of the inlet valve member and the fluid pressure in the pumping chamber exceeding a threshold value. The inlet valve arrangement comprises means for selectively applying a closing force on the inlet valve member to bias it toward the closed position, such that, in use, the application of the closing force by said means acts to increase the threshold value of the pressure difference at which the inlet valve member opens.

A fuel pump has a low pressure fuel inlet (40) and a single piston pumping chamber (10) for supplying high pressure fuel through a pump outlet to an inlet side of a common rail (16). The fuel pump comprises a primary pressure relief valve (12) having an inlet side in hydraulic communication with the inlet side of the common rail (16) and an outlet side in fluid communication with the pumping chamber (10); and an auxiliary pressure relief valve (19) having an inlet side (35) in hydraulic communication with the pumping chamber (10) and an outlet side in direct fluid communication with a fuel passage (37) at the low pressure of the pump inlet (40).

Methods and systems are provided for a direct injection fuel pump. The methods and system control pressure within a compression chamber so as to improve fuel pump lubrication.

A valve device includes a housing, a flow duct and a valve body. The valve body is arranged in the flow duct and bears with a sealing section against a housing-side sealing seat when the valve device is closed. The valve body is guided along a movement axis by a housing-side guide surface and bears with a stop surface against a housing-side movement limiting surface when the valve device is open to the maximum. The guide surface is provided by a guide element, and the sealing seat and the movement limiting surface are provided separately by the guide element.