A high-pressure pump includes a pressurizing chamber forming portion, a discharge passage forming portion, a discharge seat member, an intermediate member, a relief seat member, a discharge valve, and a relief valve. The intermediate member includes a first passage that passes through the intermediate member between one surface facing a pressurizing chamber and the other surface facing away from the pressurizing chamber. The relief valve seat includes a second passage that passes through the relief seat member between the one surface facing the pressurizing chamber and the other surface facing away from the pressurizing chamber. At least one of the intermediate member and the relief seat member includes an annular recess that fluidly connects the first passage and the second passage. The annular recess is recessed from a surface of the at least one of the intermediate member and the relief seat member facing the other.

The disclosure proposes a tappet with a housing which is composed of a drive-side and an output-side section. The drive-side section, at its outer end, has a roller and the output-side section, at its outer end, has a contact area for a follower part. The separate sections are axially spaced apart from one another and are connected to one another by a central rod piece.

A valve actuation system for an engine includes a rotatable camshaft, an injector actuation linkage, and a valve actuation linkage. The valve actuation linkage includes a valve lifter, a valve pushrod, and a rocker arm. At least one of a rocker arm center plane defined by the valve rocker arm or a lifter roller center plane defined by the valve lifter is spaced an offset distance from a pushrod axis, providing an increased contact width between an injector roller in the injector actuation linkage and one of a plurality of cam lobes of the camshaft. The valve lifter includes a fork defining a center plane spaced an offset distance from a center axis of the valve lifter. A rocker arm includes a screw bore offset relative to a rocker arm center plane.

A fuel pump for an internal combustion engine comprising a barrel having a longitudinal axis that spans between a proximal end and a distal end and a central bore therein. A plunger is disposed at least partially in the central bore and is configured to move along the longitudinal axis. An annular seal assembly is arranged around the circumference of the plunger wherein the annular seal assembly includes a seal retainer housing and a first seal and the seal retainer housing also retains the proximal end of the barrel thereon to form a second seal wherein the first and the second seals reduce the fuel to oil transfer rate and the oil to fuel transfer rate. The plunger and barrel are configured to be removed from and re-assembled with the annular seal assembly to enable service of these parts and the fuel pump.

A cam follower roller device including a tappet body extending along a longitudinal axis and defining a tappet bore, a pin centered on a transverse axis, through holes having mounting ends for supporting the pin on the tappet body, and a roller rotatably mounted on the pin around the transverse axis, the roller having a cylindrical outer surface, a central cylindrical bore and two frontal end faces. Transverse gaps are provided between frontal end faces of the roller and the tappet bore, and the central cylindrical bore of the roller is mounted around an annular rolling surface of transverse convex profile.

A tappet assembly including an outer cup having a substantially cylindrical side wall, an annular lip portion disposed at a first end of the side wall, and an annular ledge disposed on the side wall, the annular ledge being disposed in a plane that is transverse to a longitudinal center axis of the tappet assembly. An inner cup includes an annular lip extending outwardly therefrom and a pair of shaft apertures, and is disposed in the outer cup so that the lip abuts the annular ledge of the outer cup and is non-rotatably fixed thereto by the annular lip of the outer cup which abuts the lip of the inner cup. A shaft is received in the shaft apertures, and a roller tappet is rotatably received on the shaft such that a portion of the roller tappet extends axially outwardly beyond the annular lip portion of the outer cup, and an alignment device formed in the outer cup.

A tappet assembly including an outer cup having a substantially cylindrical side wall, an annular lip portion disposed at a first end of the side wall, and an annular ledge disposed on the side wall, the annular ledge being disposed in a plane that is transverse to a longitudinal center axis of the tappet assembly. An inner cup includes an annular lip extending outwardly therefrom and a pair of shaft apertures, and is disposed in the outer cup so that the lip abuts the annular ledge of the outer cup and is non-rotatably fixed thereto by the annular lip of the outer cup which abuts the lip of the inner cup. A shaft is received in the shaft apertures, and a roller tappet is rotatably received on the shaft such that a portion of the roller tappet extends axially outwardly beyond the annular lip portion of the outer cup, and an anti-rotation feature formed in the outer cup, wherein the outer surface of the outer cup is an unground surface.

A storage device is configured to store a first mapping that receives, as an input, a first input variable including a cam phase variable on present and past phases of a cam, and output a pulsating variable on a pulsating component. The execution device is configured to acquire the first input variable and estimate the pulsating variable by applying the acquired first input variable to the first mapping. Therefore, it is possible to estimate the pulsating variable without providing a low-pressure fuel pressure sensor by estimating a fuel pressure variable by applying the first input variable to the first mapping.

A method for producing a reduced friction sliding surface on a machine element includes applying a coating comprising amorphous carbon to a surface of the machine element and locally heating the coating with a laser. The coating is heated to a temperature below an evaporation temperature of the coating to achieve a local volumetric increase in the coating and a local increase in a layer thickness of the coating. A surface structure of the coating includes a multiplicity of elevations resulting from a local phase transformation of the coating from amorphous carbon into graphite due to the locally heating.

A roller tappet for a high-pressure fuel pump or for a valve drive of an internal combustion engine is provided. The tappet can be guided in a direction of a longitudinal axis thereof in a housing receptacle and can be driven displaceably by a cam shaft of the internal combustion engine. The tappet includes a tappet body which has a guide cylinder, and a cup-shaped sleeve supported axially and radially on the guide cylinder. The sleeve includes a bearing surface for the pump piston or a valve drive element, and the guide cylinder includes a rotatable roller mounted on support flanks, by means of which roller the roller tappet can be supported on the internal combustion engine camshaft. The sleeve has, at its end region facing away from the bearing surface, a ring-shaped shoulder for radial support and an end ring for axial support on the guide cylinder.