A high pressure fuel pump includes a pressurizing assembly where a plunger arranged in a bore translates along a main axis. The pump also includes a fuel transfer assembly having an inlet valve assembly and an outlet valve assembly. The pressurizing assembly has a pressurizing body provided with the bore and the fuel transfer assembly has a fuel transfer body within which are arranged the inlet and the outlet valve assemblies. The pressurizing body and the fuel transfer body are distinct parts fixed to each other along a sealing area.

A fluid injection system can include a main flow line, a primary flow line connected to the main flow line, a primary flow valve disposed on the primary flow line and configured to selectively allow injectant flow to the primary flow line, a secondary flow line connected to the main flow line, and a secondary flow valve disposed on the secondary flow line and configured to selectively allow injectant flow to the secondary flow line. The system can include a primary purge branch in fluid communication with the primary flow line and connected to a purge gas line, a primary purge valve disposed in the primary purge branch between the primary flow line and the purge gas line, a secondary purge branch in fluid communication with the secondary flow line, and a secondary purge valve disposed between the purge gas line and both of the primary purge branch and the secondary purge branch.

A solenoid assembly of a fuel pump is disclosed, including a housing having an open end and a partly closed end; a pole piece fixedly disposed within the housing; a bobbin assembly disposed within the housing and including a coil disposed proximal to the pole piece; and a bobbin retainer disposed between the open end of the housing and the bobbin assembly, a radially outer surface of the bobbin retainer contacting the housing. A portion of the housing which is adjacent the bobbin retainer has an outer surface that is recessed and an inner surface that protrudes against the bobbin retainer. The portion is created by deforming the housing to create the protrusion on the inner surface of the housing. The housing inner surface protrusion provides a press fit engagement with the bobbin retainer.

A fluid pump valve assembly includes: a valve body; a fluid inlet and a fluid outlet defined in the valve body; an inlet disk and an outlet disk movably disposed in the valve body; and a valve seat fixed within the valve body and including a disk member including at least one first aperture defined axially through the disk member, and at least one second aperture defined axially through the disk member, the inlet disk and the valve seat forming at least part of an inlet valve and the outlet disk and the valve seat forming at least part of an outlet valve. An inlet chamber is disposed upstream of the inlet valve, a pump chamber is disposed between and in fluid communication with the inlet valve and the outlet valve, and an outlet chamber is disposed downstream of the outlet valve. The inlet chamber surrounds the outlet chamber.

The hydraulic injection system (100) with cam comprises an injection valve (50) housed in a tubular injection nozzle (54), a gap being formed between a valve stem (51) of said valve (50) and the inner surface of the tubular injection nozzle (54) to allow an injectable fluid (58) coming from pressurizing means (10) to flow, while a receiver piston (62) fixed with respect to said valve (50) receives on the one hand the pressure of the injectable fluid (58) to hold said valve (50) closed, and on the other hand, the pressure of a hydraulic fluid (60) to open said valve (50), an injection cam (67) being capable to move said receiver piston (62) via an emitter piston (69) and said hydraulic fluid (60).

To increase a valve-opening pressure at which a pressure relief valve is opened in order to deal with a higher pressure of the fuel, a large pressure relief valve is installed in a high-pressure fuel supply pump. This upsizes the high-pressure fuel supply pump. A pressure relief valve is installed in a discharge joint. This can provide a high-pressure fuel supply pump that is not large too much and sufficiently performs a relief function by efficiently using the excessive space in the pump even when the fuel pressure is increased.

The invention relates to a pump unit for feeding fuel, preferably diesel fuel, to an internal combustion engine, comprising at least one cylinder (14), a piston (15) which is displaceably arranged in the cylinder (14), and a pressure valve (30) for selectively controlling the supply of fuel to the internal combustion engine, wherein the pressure valve (30) has a closure part (38, 46, 51) provided with a cavity (44, 49, 53) that opens to the outside on an end surface (43, 48, 52) facing the piston (15) of the closure part (38, 46, 51).

There is provided a discharge valve mechanism provided at an outlet of a pressurizing chamber of a high-pressure fuel supply pump that aims to reduce a backflow amount of fuel from a discharge valve and to prevent cavitation erosion. There are provided a discharge valve disposed on a discharge side of a pressurizing chamber, a discharge valve seat that closes a discharge side flow passage of the pressurizing chamber by seating the discharge valve, and a discharge valve spring that presses the discharge valve toward the discharge valve seat. It is configured such that, in a case where a minimum seat diameter of a seat portion in which the discharge valve is seated on the discharge valve seat is set to D and a spring force of the discharge valve spring at a time of setting is set to F, a coefficient K obtained by dividing the spring force F by the minimum seat diameter D is set to be 0.2 or more.

A high-pressure fuel pump includes a housing including a chamber, an inlet flow passage to draw fuel into the chamber, and a discharge flow passage to discharge fuel out of the chamber. The high-pressure fuel pump further includes a piston disposed in the housing and configured to compress fuel, a sleeve coupled to the housing and configured to support the piston and form a space for storing fuel, a discharge valve disposed in the discharge flow passage and configured to open when a pressure of fuel stored in the chamber is equal to or greater than a first pressure, and a pressure relief valve disposed in a relief flow passage that communicates with the discharge flow passage and the space. The pressure relief valve is configured to open when a pressure of fuel supplied into the relief flow passage is equal to or greater than a second pressure.

A fuel pump includes a fuel pump housing with a pumping chamber and an outlet valve bore extending along an outlet valve bore axis; a pumping plunger which reciprocates within a plunger bore along a plunger bore axis which is traverse to the outlet valve bore axis; and an outlet valve assembly. The outlet valve assembly includes an outlet valve seat with an outlet flow passage, wherein a first portion of the outlet valve seat is aligned with the pumping plunger in a direction parallel to the plunger bore axis and wherein a second portion of the outlet valve seat is not aligned with the pumping plunger in a direction parallel to the plunger bore axis and an outlet valve member which is moveable between an unseated position which provides fluid communication through the outlet flow passage and a seated position which prevents fluid communication through the outlet flow passage.