A system for preventing rotation of a tappet includes a tappet having an outer casing and a central axis which is configured to reciprocate linearly along the central axis. The outer casing includes a flat portion having a length along the central axis and having a width. Additionally, the system includes a lock bar fixed in position relative to the linear oscillation of the outer casing. The lock bar is positioned in proximity to the flat portion of the outer casing. Upon rotation of the outer casing about the central axis, the lock bar is configured to come into contact with the cuter casing and inhibit additional rotation of the outer casing.

A high pressure fuel pump has a piston extending outside a pump head toward an end provided with a spring seat cooperating with a cam follower. A pump spring compressed between the pump head and the cam follower maintains the follower in contact with a revolving cam. The pump is further provided with a flexible tubular sealing sleeve engaged around the piston and extending between the pump head and the cam follower so that the internal space of the sleeve is sealingly isolated from the outer space.

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.

The disclosure relates to a tappet for acting on a pump piston of a high-pressure fuel pump of an internal combustion engine. The tappet includes a tubular housing, and at the upper annular end face of the tubular housing, two surfaces which are indented relative to the outer casing of the housing and comprise a pin that supports a cam roller, lie diametrically opposite each other. An upper end face of a transverse beam lies against axial inner end faces of the two surfaces. A transverse beam lower end face, which faces a lower annular end face of the housing, is provided with a pin, which protrudes from the housing and is surrounded by a spring plate supported against the inner casing of the housing. A sleeve-like inner collar of the spring plate guides the unstepped pin.

The purpose of the present invention is to increase the pressure of fuel while reducing an increase in the maximum lift amount of a cam and deterioration of a fuel injection ability. This cam for use in a fuel injection pump that increases the pressure of fuel supplied into a fuel supply chamber by an axial movement of a plunger. The cam includes a first cam surface that causes an increase rate of an axial speed of the plunger when the cam rotates at a constant speed, in a pre-stroke period until the plunger increases the pressure of the fuel in the fuel supply chamber, to be a first increase rate, and a second cam surface that causes the increase rate of the axial speed of the plunger when the cam rotates at the constant speed, in a pressure increasing period that is a period from a start of increasing the pressure of the fuel in the fuel supply chamber by the plunger, to be a second increase rate, wherein the first increase rate is set higher than the second increase rate.

A lubricated high pressure fuel pump assembly is provided, comprising a fuel pump, a sealed enclosure and a pump lubrication circuit. The fuel pump includes a pump drive shaft via which the fuel pump is configured to be mechanically driven. The sealed enclosure is configured to surround a first portion of the pump drive shaft, wherein the first portion is exterior to the fuel pump. The pump lubrication circuit comprises a lubricant reservoir and a lubricant pump configured to pump lubricant from the lubricant reservoir to the pump drive shaft. The sealed enclosure is configured to prevent fluid leakage from the fuel pump via the first portion of the pump drive shaft and the lubricant reservoir is configured to collect the lubricant from the pump drive shaft, such that the lubricant is retained within the lubricated high pressure fuel pump assembly.

A high-pressure fuel pump and a protector are coupled to an outer side of an engine body of an internal combustion engine. A wall plate surrounds the high-pressure fuel pump to protect the high-pressure fuel pump. A cover of the high-pressure fuel pump has a flange. The engine body has a mounting surface. The bottom plate and the flange are fastened to the mounting surface by a bolt with the bottom plate held between the flange and the mounting surface.

A cam follower assembly having a plastic guide body and a cam follower having two opposing roller shaft ends is provided. The single piece guide body includes a pair of grooved members. Each of the grooved members include an interior surface defining an elongated guide groove having a recessed surface. The elongated guide grooves are facing and aligned with each other. The cam follower is disposed between the pair of grooved member such that one of the roller shaft ends is received in one guide groove and the opposite roller shaft end is received in the other of the guide groove. The roller shaft ends are slidable in a reciprocal axial direction within the elongated guide grooves and retained between the recessed surfaces. The plastic guide body may be injection molded from a nylon material having glass fibers.

A diesel engine including: a cam shaft driven by a crankshaft, a fuel injection pump driving cam provided on the cam shaft and configured to drive a fuel injection pump, and an intake cam provided on the cam shaft and configured to drive an intake valve. The fuel injection pump driving cam has a maximum radius portion, a minimum radius portion, an intermediate portion having a radius smaller than that of the maximum radius portion and larger than that of the minimum radius portion, and a slant portion where the intermediate portion shifts to the minimum radius portion in a reverse rotation direction of the driving cam. The position where the intermediate portion shifts to the slant portion begins after the intake valve is opened to an extent corresponding to at least half of a maximum lift of the intake valve.

A roller lifter includes a lifter body having a cylindrical peripheral wall with a sliding surface on an outer periphery thereof and a roller rotatably mounted via a shaft member on the lifter body and brought into contact with a cam. The sliding surface is reciprocally slid in a sliding hole of a lifter guide. The peripheral wall has a thicker part in a part thereof in a circumferential direction. The thicker part is shaped such that a thickening part is annexed to an outer wall part formed continuously with a constant thickness in the circumferential direction. The thicker part is formed with a rotation stopper bulging outward. The rotation stopper enters a guide groove communicating with the sliding hole of the lifter guide.