A tappet, which may be a fuel pump actuator, includes a body that is a contiguous piece of case-hardened ferrous metal. The body has a cylinder-conforming bore-running surface and an anti-rotation guide feature that has been made by stamping to project outwardly from the bore-running surface. A cam follower is mounted to the body. The body has been case hardened by ferritic nitrocarburizing, but has not been distorted by heat treatment and has a malleable interior. A transverse web for the tappet may be fully hardened. Axle holes for the cam follower may be formed by stamping. The tappet is durable and provides superior alignment of the roller to a cam, which reduces friction and noise.

A pump body of a high-pressure pump includes a pressure chamber formed in a deep portion of a cylinder. A plunger reciprocates within the cylinder to vary a volume of the pressure chamber. A discharge path and a supply path are formed in the pump body and extend in a radial direction of the cylinder from the pressure chamber. A pin provided at an end of the plunger in the pressure chamber protrudes in one radial direction of the plunger to the outside of an inner circumference of the cylinder. In this case, the pin is engaged with a step portion between the cylinder and the pressure chamber in a state before attachment of the high-pressure pump to an internal combustion engine. Accordingly, separation of the plunger from the cylinder is avoidable.

A plunger of a high-pressure pump is provided reciprocatably on an inner side of a cylinder. A holder disposed on an opposite side of the cylinder from a pressurizing chamber includes a large tubular portion that provides a predetermined space between the large tubular portion and an outer wall of the plunger, and a small tubular portion that is disposed on an opposite side of the large tubular portion from the cylinder. A pin inserted into a hole of the plunger at a position corresponding to the large tubular portion protrudes radially outward from the outer wall of the plunger and is accommodated in a space on an inner side of the large tubular portion.

An object of the present invention is to secure a gap between a component on a suction valve side and a component on an anchor side when a valve is closed, regardless of an integration tolerance of a plurality of components, and to be able to reliably close the valve. In an electromagnetic valve mechanism 300 including an anchor assembly 36 and a magnetic core 33 between which a magnetic attraction force acts, and a suction valve 30 configured to be able to come into and out of contact with the anchor assembly 36, the anchor assembly 36 includes a first anchor assembly component 36a having a facing surface 36ab that faces the magnetic core 33, a second anchor assembly component 36b configured integrally with the first anchor assembly component 36a, and a press-fitting portion 36c that fixes the first anchor assembly component 36a and the second anchor assembly component 36b. A press-fitting length L1 of the press-fitting portion 36c is set to a length at which the second anchor assembly component 36b and the suction valve 30 are separated from each other in a state where the suction valve 30 is closed.

A tappet roller assembly in which a roller shoe has a roller bore shaped to receive and retain a roller. The roller is sized and configured to rotate within the roller bore. The roller shoe may have a lubricating passage extending from a peripheral surface of the roller shoe to the roller bore to lubricate the roller.

A high-pressure fuel pump includes a pump housing, a pump piston accommodated in a receiving opening of the pump housing, a high-pressure seal which surrounds the pump piston in a sealing manner and which seals off a high-pressure region from a low-pressure region, and a guide device which comprises at least two guide portions that are axially spaced apart from one another and guide the pump piston with a sliding fit. The at least two guide portions are arranged in the receiving opening of the pump housing. A first guide portion is arranged, as seen in an axial direction, on a side of the high-pressure seal facing toward the delivery space. And a second guide portion is arranged, as seen in the axial direction, on a side of the high-pressure seal facing away from the delivery space.

A cam ring of a supply pump revolves around a camshaft without rotating. A tappet reciprocates in a direction perpendicular to the camshaft in response to revolution of the cam ring such that the tappet slides along a cam ring sliding surface. A plunger reciprocates together with the tappet to pressurize and deliver fuel. The cam ring sliding surface is shaped in a convex form that has a curved contour line which is non-circular. A height of an inside of the cam ring sliding surface is higher than a height of a periphery of the cam ring sliding surface. Specifically, an ellipsoidal surface portion is formed at the cam ring sliding surface, and an axial direction of a major axis of the ellipsoidal surface portion is set to coincide with a direction perpendicular to a sliding direction of the cam ring sliding surface.

In a reciprocating high-pressure fuel pump that operates a plunger while facing a cam ridge of a plunger driving cam provided on a camshaft to which power of a crankshaft of an internal combustion engine is transmitted, the cam ridge includes a cam curved surface including two apexes at a cam angle interval of 180° and two valley bottoms at a cam angle interval of 180° and alternately connecting the apexes and the valley bottoms, and a crossing angle between a first virtual line connecting the two apexes and a second virtual line connecting the two valley bottoms is not a right angle as viewed in a direction of a camshaft axis.

Disclosed herein are devices, systems, and methods relating to high-pressure fuel pump designs and features. A high-pressure fuel pump assembly includes a body, a camshaft, and an embossment. The body has a forward end and a rearward end opposite thereof and configured to couple to a low-pressure fuel pump. The camshaft is received and secured within a central bore of the body so as to be rotationally movable within the central bore. A coupler end of the camshaft is configured to couple to a drive shaft of the low-pressure fuel pump. The embossment includes at least one fastener boss configured to receive a fastener to couple the low-pressure fuel pump to the high-pressure fuel pump assembly. The embossment is formed at the rearward end of the body such that thermal stresses that cause geometrical deformations at the embossment are reduced through a range of engine temperature operating conditions.

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.