A roller tappet for a fuel pump is provided that has a guide housing which includes a drive-side and output-side section of the same external diameter, and a separate support body extending longitudinally through the guide housing. An upper face on the drive-side section carries a pin with a roller thereon. A lower face of the output-side section interacts at least indirectly with an arrangement for a pump piston. The guide housing includes a drive-side section and an output side section that are separate, axially spaced rings connected to one another via the support body. The support body has a first ring area with the upper face and a second ring area with the lower face. The first ring area is connected to an inner jacket of the drive-side section and the second ring area is connected to an inner jacket of the output-side section.

A tappet assembly (100) used in mechanical equipment includes a tappet body (108) having a cylindrical shape and including a lower carrier portion (152) and an upper shell portion (158) having a cavity (150) defined by an inner wall (160) of the upper shell portion (158) and a top surface (154) of the lower carrier portion (152). The lower carrier portion (152) and the upper shell portion (158) are integrally formed as a single-piece unit. A post (162) extends upwardly from the top surface (154) of the lower carrier portion (152) and is configured to reduce a peak contact pressure associated with the tappet body (108).

A tappet assembly (100) used in mechanical equipment includes a tappet body (108) having a cylindrical shape and including a lower carrier portion (152) and an upper shell portion (158) having a cavity (150) defined by an inner wall (160) of the upper shell portion (158) and a top surface (154) of the lower carrier portion (152). The lower carrier portion (152) and the upper shell portion (158) are integrally formed as a single-piece unit. A post (162) extends upwardly from the top surface (154) of the lower carrier portion (152) and is configured to reduce a peak contact pressure associated with the tappet body (108).

An engine valve actuation system includes a camshaft, rotatable in an engine, and a compound collar including a mounting sleeve, a guide sleeve, and a bridge cantilevering the guide sleeve to the mounting sleeve. A first valve lifter is interference-fitted in the mounting sleeve, and a second valve lifter is slip-fitted within the guide sleeve. First and second lifter bores receiving the first and second valve lifters are congruent, and the first and second valve lifters may be substantially identical. The compound collar reciprocates with the interference fitted first valve lifter, slidably receives the slip-fitted second valve lifter, and limits in-service rotation of both.

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 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.

An engine valve actuation system includes a camshaft, rotatable in an engine, and a compound collar including a mounting sleeve, a guide sleeve, and a bridge cantilevering the guide sleeve to the mounting sleeve. A first valve lifter is interference-fitted in the mounting sleeve, and a second valve lifter is slip-fitted within the guide sleeve. First and second lifter bores receiving the first and second valve lifters are congruent, and the first and second valve lifters may be substantially identical. The compound collar reciprocates with the interference fitted first valve lifter, slidably receives the slip-fitted second valve lifter, and limits in-service rotation of both.

An engine valve actuation system includes a rotatable camshaft, a first valve lifter, and a second valve lifter, structured to actuate valves in an engine in response to rotation of cams of the camshaft. The engine valve actuation system includes an anti-rotation device having a collar with a sleeve portion and a boss portion, and a bridge connector structured to couple with one of the valve lifters. Another one of the valve lifters is slidably received in the sleeve portion. The anti-rotation device reciprocates with the one of the valve lifters, and each of the valve lifters is restricted from rotation during service.

A valve actuation system comprising a valve actuation motion source configured to provide a main event valve actuation motion to at least one engine valve via a main motion load path that comprises at least one valve train component. The valve actuation system further includes a lost motion component arranged within a first valve train component in the main motion load path, the lost motion component being controllable to operate in a motion conveying state or a motion absorbing state. The valve actuation system also comprises a high lift transfer component arranged in the main motion load path, with the high lift transfer component being configured to permit the main motion load path to convey at least a high lift portion of the main event valve actuation motion when the lost motion component is in the motion absorbing state.

A valve bridge to operatively interface with a rocker arm and a valve, and systems, assemblies, and methods thereof can comprise: a body, of the valve bridge, having a first side and a second side opposite the first side, a first leg of the valve bridge extending from the first side of the body, a second leg of the valve bridge extending from the first side of the body, and a third leg of the valve bridge extending from the first side of the body. A first pin can extend from an end of the first leg opposite the body, and a second pin can extend from an end of the second leg opposite the body.