The disclosure relates to fuel pump housings and fuel pump systems incorporating the same. The fuel pump housing includes at least one tappet housing portion configured to receive at least one tappet assembly and a main bore portion fluidly coupled with the at least one tappet housing portion such that the main bore receives a camshaft. The main bore includes an uncut portion and at least one relief cut portion proximal to the at least one tappet housing portion. The uncut portion defines a first centerline, and the relief cut portion defines a second centerline offset from the first centerline.

A high pressure fuel pump includes: a pump body that forms a suction passage and a pressurizing chamber and slidably supports a plunger; and a control valve that opens a connection between the suction passage and the pressurizing chamber in a suction stroke, during which the plunger is driven toward a suction side for suctioning fuel into the pressurizing chamber, while the control valve controls closing timing, at which the connection between the suction passage and the pressurizing chamber is closed by the control valve in a delivery stroke, during which the plunger is driven toward a delivery side for delivering the fuel out of the pressurizing chamber. The pump body forms a release passage that is communicated with the suction passage. The release passage relieves the fuel, which is pressurized by the plunger, from the pressurizing chamber before the closing timing during the delivery stroke.

A high pressure fuel pump includes: a pump body that forms a suction passage and a pressurizing chamber and slidably supports a plunger; and a control valve that opens a connection between the suction passage and the pressurizing chamber in a suction stroke, during which the plunger is driven toward a suction side for suctioning fuel into the pressurizing chamber, while the control valve controls closing timing, at which the connection between the suction passage and the pressurizing chamber is closed by the control valve in a delivery stroke, during which the plunger is driven toward a delivery side for delivering the fuel out of the pressurizing chamber. The pump body forms a release passage that is communicated with the suction passage. The release passage relieves the fuel, which is pressurized by the plunger, from the pressurizing chamber before the closing timing during the delivery stroke.

A pump unit for feeding fuel, preferably diesel fuel, to an internal combustion engine; the pump unit (1) comprising: a head (4) inside which a cylinder (12) extending along an axis (A1) is formed; a pumping piston (5) extending along the axis (A1) and slidingly coupled with the cylinder (12); a through-hole (13) which extends from the cylinder (12) towards the outside of the pump unit (1); an intake chamber (8) communicating with the cylinder (12) via the hole (13); an intake valve (7) which controls the flow of fuel from the intake chamber (8) to the hole (13); a cap (23; 123; 223) which is connected to the head (4), is arranged on the opposite side to the pumping piston (5) and can be selectively fixed along an outer surface (25) of the head (4) so as to close the intake chamber (8) on one side.

A pump unit for feeding fuel, preferably diesel fuel, to an internal combustion engine; the pump unit (1) comprising: a head (4) inside which a cylinder (12) extending along an axis (A1) is formed; a pumping piston (5) extending along the axis (A1) and slidingly coupled with the cylinder (12); a through-hole (13) which extends from the cylinder (12) towards the outside of the pump unit (1); an intake chamber (8) communicating with the cylinder (12) via the hole (13); an intake valve (7) which controls the flow of fuel from the intake chamber (8) to the hole (13); a cap (23; 123; 223) which is connected to the head (4), is arranged on the opposite side to the pumping piston (5) and can be selectively fixed along an outer surface (25) of the head (4) so as to close the intake chamber (8) on one side.

Pump, in particular a high-pressure fuel pump, having at least one pump element (10) which has a pump piston (12) which is driven in a reciprocating movement by way of a drive shaft (14) with at least one cam (16; 160) and delimits a pump working chamber (24) which can be filled with delivery medium via an inlet valve (26) during the suction stroke of the pump piston (12). The at least one cam (60; 160) of the drive shaft (14) is a multiple cam with a plurality of cam delivery regions (16a, 16b) for the delivery strokes of the pump piston (12), or a plurality of single or multiple cams (160) with in each case at least one cam delivery region (160a, 160b) for the delivery strokes of the pump piston (12) are provided which are arranged next to one another in the direction of the rotational axis (15) of the drive shaft (14). The cam profiles of the cam delivery regions (16a, 16b) of the at least one multiple cam (16) or the cam profiles of the cam delivery regions (160a, 160b) of the single cams (160) are of different configuration.

Pump, in particular a high-pressure fuel pump, having at least one pump element (10) which has a pump piston (12) which is driven in a reciprocating movement by way of a drive shaft (14) with at least one cam (16; 160) and delimits a pump working chamber (24) which can be filled with delivery medium via an inlet valve (26) during the suction stroke of the pump piston (12). The at least one cam (60; 160) of the drive shaft (14) is a multiple cam with a plurality of cam delivery regions (16a, 16b) for the delivery strokes of the pump piston (12), or a plurality of single or multiple cams (160) with in each case at least one cam delivery region (160a, 160b) for the delivery strokes of the pump piston (12) are provided which are arranged next to one another in the direction of the rotational axis (15) of the drive shaft (14). The cam profiles of the cam delivery regions (16a, 16b) of the at least one multiple cam (16) or the cam profiles of the cam delivery regions (160a, 160b) of the single cams (160) are of different configuration.

Fuel pump for a direct injection system provided with a common rail. The fuel pump has a pumping chamber defined in a main body; a piston which is mounted in a sliding manner inside the pumping chamber to cyclically vary the volume of the pumping chamber; an intake channel which originates from a wall of the pumping chamber; an intake valve which is coupled to the intake channel; a delivery channel which originates from a wall of the pumping chamber; a delivery valve which is coupled to the delivery channel; and an actuating spring which has a plurality of turns having a pitch that varies between the turns and that is coupled to the piston so as to push the piston towards a maximum volume or minimum volume position of the pumping chamber.

Fuel pump for a direct injection system provided with a common rail. The fuel pump has a pumping chamber defined in a main body; a piston which is mounted in a sliding manner inside the pumping chamber to cyclically vary the volume of the pumping chamber; an intake channel which originates from a wall of the pumping chamber; an intake valve which is coupled to the intake channel; a delivery channel which originates from a wall of the pumping chamber; a delivery valve which is coupled to the delivery channel; and an actuating spring which has a plurality of turns having a pitch that varies between the turns and that is coupled to the piston so as to push the piston towards a maximum volume or minimum volume position of the pumping chamber.

Disclosed is a pump, in particular a high-pressure fuel pump, comprising at least one pump element (10) that has a roller tappet (20) inside which a roller (42) is rotatably mounted on a bearing bolt (44) by means of a bearing sleeve (46), said roller (42) rolling off a cam (22) of an input shaft (24). The bearing sleeve (46) is made of a plastic material, especially polyether ether ketone (PEEK) or polyphthalamide (PPA).