A follower mechanism movable within a bore, the mechanism including an outer cup with a substantially cylindrical side wall and a first annular lip portion disposed at a first end of the side wall, an inner cup including a side wall portion defining a pair of shaft apertures and a ledge that is transverse to a longitudinal center axis of the follower mechanism, the inner cup being disposed in the outer cup so that the first annular lip portion of the outer cup abuts a top surface of the side wall portion of the inner cup, a pallet having an outer perimeter, at least a portion of the outer perimeter being adjacent the ledge of the inner cup, a shaft having a first end and a second end disposed in the shaft apertures, and a roller follower rotatably received on the shaft.

A fuel pump assembly comprises a plunger arranged to reciprocate within a plunger bore via a drive shaft, to perform a pumping cycle comprising a pumping stroke and a return stroke, the pumping stroke comprising movement of the plunger from a bottom dead centre (BDC) position to a top dead centre (TDC) position, and the return stroke comprising movement of the plunger from the TDC position to the BDC position. The fuel pump assembly comprises a spring assembly including a return spring that is cooperable, at a first end, with a first member coupled to the plunger and movable at a first speed dependent on the speed of rotation of the drive shaft and, at a second end, with a second member which is movable at a damped speed relative to the first speed.

A pumping assembly includes at least one removable unit barrel pumping assembly coupled to a housing of the pumping assembly. The pumping assembly further includes a drive member having a roller configured to engage a portion of the unit barrel pumping assembly during operation of the pumping assembly. The roller is configured to include a plurality of geometric shapes to distribute load forces during operation of the pumping assembly.

A method and a system provide direct injection of an improver enriched fuel into an internal combustion engine of a motor vehicle. The method comprises providing a fuel with a fuel pump under a first pressure at a fuel inlet of an injector nozzle and providing a fuel improver with an improver pump under a second pressure at an inlet bore of the injector nozzle arranged downstream of the fuel inlet with respect to a nozzle outlet of the injector nozzle. The second pressure is higher than the first pressure at least for a limited time interval prior to injection to enrich the fuel with the fuel improver within the injector nozzle. The method also comprises injecting the improver enriched fuel into the internal combustion engine at the nozzle outlet.

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.

A high-pressure fuel pump includes a drive shaft, and a vane pump and a plunger pump which are driven by the drive shaft. The vane pump is configured to supply pre-pressurized fuel to the plunger pump. The drive shaft includes a cam configured to drive a piston rod of the plunger pump such that the plunger pump alternately executes a fuel suction stroke and a fuel discharge stroke. The drive shaft further includes a shaft portion for driving a rotor of the vane pump. The vane pump is configured such that for each fuel suction stroke of the plunger pump the vane pump provides a fuel supply cycle that is advanced by a phase angle relative to the fuel suction stroke.

A cam roller pin is rotationally fixed and defines a pin axis around which a cam roller is configured to rotate and apply a load at a load zone at a radially outer and lower end of the pin. The pin includes a reservoir configured to receive lubricant for lubrication of the cam roller rotating on the pin, a first lubricant path extending radially inward from the reservoir, a second lubricant path extending from the first lubricant path to a second lubricant path outlet, and a third lubricant path extending from the first lubricant path to a third lubricant path outlet.

A cam roller pin is rotationally fixed and defines a pin axis around which a cam roller is configured to rotate and apply a load at a load zone at a radially outer and lower end of the pin. The pin includes a reservoir configured to receive lubricant for lubrication of the cam roller rotating on the pin, a first lubricant path extending radially inward from the reservoir, a second lubricant path extending from the first lubricant path to a second lubricant path outlet, a third lubricant path extending from the first lubricant path to a third lubricant path outlet, and a load zone lubricant path extending from a load zone lubricant path inlet to the first lubricant path, the second lubricant path, and/or the third lubricant path.

A fuel pump includes a plunger that reciprocates, a retainer having a mounting portion attached to a lower end portion of the plunger, and a spring that biases the plunger via the retainer. The mounting portion has an engagement portion that is engaged with a constricted portion formed at the lower end portion of the plunger. A diameter of a circle formed by a corner portion of the engagement portion and an inner peripheral wall of the spring is smaller than a diameter of the lower end portion of the plunger.

The disclosure relates to a roller tappet for a high-pressure fuel pump. The roller tappet includes a housing that accommodates a cam contact roller next to a drive-side annular face of the housing. A bridge piece sits on an inner lateral surface of the housing, after the cam contact roller, as viewed from the drive-side annular face. An outer end face of the bridge piece has a rest for a pump piston. A separate adapter bolt protrudes from the rest beyond the output-side annular face of the housing; an end face of the adapter bolt, remote from the bridge piece, serves as a direct rest for the pump piston. An annular disc sits next to the output-side annular face of the housing, and the bore of said annular disc surrounds and retains the adapter bolt.