Abstract: 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).

Abstract: 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).

Abstract: A pump unit for supplying fuel, preferably diesel oil, to an internal combustion engine has at least two cylinders (10), which are formed in at least one head (9), are slidingly engaged by respective pistons (13), and communicate hydraulically with respective fuel inlets (11) in the cylinders (10) via respective interposed intake valves (15) provided with respective valve bodies (16) incorporated in the head (9); the inlets (11) of all the cylinders (10) being closed by a single cover (33) fixed to the head (9).

Abstract: A pump unit for supplying fuel, preferably diesel oil, to an internal combustion engine has at least two cylinders (10), which are formed in at least one head (9), are slidingly engaged by respective pistons (13), and communicate hydraulically with respective fuel inlets (11) in the cylinders (10) via respective interposed intake valves (15) provided with respective valve bodies (16) incorporated in the head (9); the inlets (11) of all the cylinders (10) being closed by a single cover (33) fixed to the head (9).

Abstract: A high-pressure pump for feeding fuel to an internal combustion engine has a pump housing; a fuel delivery duct; and a check valve, which is arranged along the delivery duct, and comprises a fuel chamber; a valve member mobile within the fuel chamber; and a biasing and guiding assembly, which has a fastening member suitable for being fastened to the pump housing and sealing the fuel chamber in a fluid-tight manner; a helical spring suitable for biasing the valve member; and a bushing arranged about the helical spring in order to prevent bending of the helical spring.

Abstract: The high-pressure pump has at least one pump element with a pump piston driven in a reciprocating motion and guided displaceably in a cylinder bore of a pump housing part which piston defines a pump work chamber that can be filled with fuel from a fuel inlet via a suction valve in the intake stroke. The suction valve has a pistonlike valve member which has a cylindrical shaft and a head of larger cross section at least the shaft is guided displaceably in a guide bore of a valve housing. The head of the valve member is also guided displaceably in a bore of the valve housing, via guide portions embodied on the valve member and spaced apart from one another in the circumferential direction; between the guide portions, flowthrough portions of reduced cross section compared to the guide portions provide for fuel flow out of the fuel inlet into the pump work chamber.

Abstract: A high-pressure pump for feeding fuel to an internal combustion engine has a pump housing; a fuel delivery duct; and a check valve, which is arranged along the delivery duct, and comprises a fuel chamber; a valve member mobile within the fuel chamber; and a biasing and guiding assembly, which has a fastening member suitable for being fastened to the pump housing and sealing the fuel chamber in a fluid-tight manner; a helical spring suitable for biasing the valve member; and a bushing arranged about the helical spring in order to prevent bending of the helical spring.

Abstract: The high-pressure pump has at least one pump element with a pump piston driven in a reciprocating motion and guided displaceably in a cylinder bore of a pump housing part which piston defines a pump work chamber that can be filled with fuel from a fuel inlet via a suction valve in the intake stroke. The suction valve has a pistonlike valve member which has a cylindrical shaft and a head of larger cross section at least the shaft is guided displaceably in a guide bore of a valve housing. The head of the valve member is also guided displaceably in a bore of the valve housing, via guide portions embodied on the valve member and spaced apart from one another in the circumferential direction; between the guide portions, flowthrough portions of reduced cross section compared to the guide portions provide for fuel flow out of the fuel inlet into the pump work chamber.