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.

Systems for valve actuation in internal combustion engines provide for control of rocker arms and other valvetrain components by utilizing biasing and stroke limited components. Such features may be implemented in any valvetrain component, including e-foot assemblies or pushrod assemblies. The biasing component may bias the cam side of a lost motion rocker toward the cam. The components may be extendable to permit a biasing mechanism to keep the valvetrain components in a controlled position at all times. Stroke limiting features may facilitate the formation of small gaps between valvetrain components during the engine cycle for improved lubrication. Stroke limiting features may also retain valvetrain components in an assembled configuration even when not installed in an engine or valve actuation system.

A cam follower, comprising: a tappet which includes two flanges provided with opposite holes centered on a transverse axis; a pin extending along the transverse axis between two opposite ends received in the opposite holes; and a roller movable in rotation relative to the pin around the transverse axis and adapted to roll on a cam. Each of the opposite holes is provided with: an open portion for mounting the pin by translation in a first direction perpendicular to the transverse axis, a cylindrical portion for supporting the pin along the first direction and a plane portion for retaining the pin along the transverse axis during transport and mounting of the cam follower. A method includes steps for manufacturing such a cam follower.

A cam follower, comprising: a tappet which includes two flanges provided with opposite holes centered on a transverse axis; a pin extending along the transverse axis between two opposite ends received in the opposite holes; and a roller movable in rotation relative to the pin around the transverse axis and adapted to roll on a cam. Each of the opposite holes is provided with: an open portion for mounting the pin by translation in a first direction perpendicular to the transverse axis, a cylindrical portion for supporting the pin along the first direction and a plane portion for retaining the pin along the transverse axis during transport and mounting of the cam follower. A method includes steps for manufacturing such a cam follower.

An engine component, for example a piston ring, including a wear resistant coating applied by physical vapor deposition (PVD) is provided. The coating includes tetrahedral amorphous carbon (ta-C), the carbon of the coating includes sp.sup.3 hybrid orbitals, and the coating includes boron in an amount of 0.1 wt. % to 4.0 wt. %, based on the total weight of the coating. The doped boron makes the coating less sensitive to the ion energy during the physical vapor deposition (PVD) process, improves adhesion of the coating, and expected to reduce compressive stress in the coating. Thus, the boron-doped ta-C coating can be applied to a greater thickness compared to ta-C coatings without the doped boron. In addition, there is a strong indication that the addition of boron will maintain a high level of sp.sup.3 bonded carbon and a high microhardness.

An engine component, for example a piston ring, including a wear resistant coating applied by physical vapor deposition (PVD) is provided. The coating includes tetrahedral amorphous carbon (ta-C), the carbon of the coating includes sp.sup.3 hybrid orbitals, and the coating includes boron in an amount of 0.1 wt. % to 4.0 wt. %, based on the total weight of the coating. The doped boron makes the coating less sensitive to the ion energy during the physical vapor deposition (PVD) process, improves adhesion of the coating, and expected to reduce compressive stress in the coating. Thus, the boron-doped ta-C coating can be applied to a greater thickness compared to ta-C coatings without the doped boron. In addition, there is a strong indication that the addition of boron will maintain a high level of sp.sup.3 bonded carbon and a high microhardness.

The variable valve actuating device (20) comprises a valve lifter (24) interposed between a swing end of a rocker arm 22 and a stem end of an engine valve (17), and a switch pin (53) slidably received in the valve lifter (24) so as to selectively abut the end surface of the valve stem as the valve lifter is actuated by a cam (21a). The swing end of the rocker arm abuts an upper end of a projection (55) projecting from the upper end of the valve lifter via an engagement feature (26b, 55a) that prevents a rotational movement of the valve lifter relative to the swing end around the axial line of the valve stem.

A valve switching apparatus includes a rocker arm coming into contact with a cam to open and close a valve along with a rotation of the cam, and an eccentric generation means provided to the rocker arm so as to allow an eccentric position to be changed by rotation thereof.

A lost motion mechanism can comprise a castellation device, comprising a casing, an upper castellation, and a lower castellation. The casing can comprise a first linear slot and a second linear slot perpendicular to the first linear slot. Upper castellation can comprise an upper body, spaced upper teeth extending from the upper body, the spaced upper teeth forming spaced upper gaps therebetween, and an actuation peg extending from the upper body into the first linear slot. Lower castellation can comprise a lower body, spaced lower teeth extending from the lower body, the spaced lower teeth forming spaced lower gaps therebetween, and an anti-rotation peg extending from the lower body into the second linear slot. An actuator can be configured with the lost motion mechanism so that a movable arm comprises a forked end configured to move on the actuation peg as the movable arm swivels.

An internal combustion engine has a valvetrain that includes a rocker arm assembly on which is mounted an electronic device and at least a part of a generator. The generator converts some of the mechanical energy that is transmitted through the rocker arm assemblies into electricity. That electricity may be used to power an electric latch, a transmitter, or another type of rocker arm assembly-mounted electrical device. Various generator configurations are described. In some configurations, the generator is piezoelectric. In other configurations, the generator is electromagnetic. In some configurations, the generator is driven by force transmitted by the rocker arm assembly from a cam. In some configurations, the generator is driven by vibrations.