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 rocker assembly for a type III center pivot valvetrain comprises a rocker arm having a cam end, a center pivot bore, and a valve end which includes a first actuator bore and a second actuator bore. The rocker assembly further comprises a a cylinder deactivation actuator arranged in the first actuator bore. The cylinder deactivation actuator comprises a hydraulically actuated latch assembly configured to selectively switch between a latched configuration and an unlatched configuration and a a mechanical lash-setting sleeve distanced from a travel stop defined within the first actuator bore. The cylinder deactivation actuator further comprises a lash step disposed below the mechanical lash-setting sleeve and extending into the first actuator bore. The hydraulically actuated latch assembly is configured to selectively travel between the travel stop and the lash step when the hydraulically actuated latch assembly is in the latched configuration.

A compression-release engine brake system operating an exhaust valve of an engine during a compression-release engine braking operation. The compression-release brake system comprises an exhaust rocker arm and a brake reset device disposed in a reset bore formed in the exhaust rocker arm. The brake reset device comprises a reset check valve, a slider-piston slidably disposed in the reset bore and an external slider bias spring biasing the piston foot away from the brake reset device. The external slider bias spring is disposed outside the reset bore and around the piston-slider. The brake reset device permits pressurized hydraulic fluid to flow from a supply conduit to a reset conduit to supply a brake actuation piston when the reset check valve is open. The actuation piston extends and engages the exhaust valve toward the end of a compression stroke of the internal combustion engine, and the brake reset device resets.

A valve actuation system comprises a valve actuation motion source configured to provide main and auxiliary valve actuation motions for actuating at least one engine valve via a valve actuation load path. A lost motion subtracting mechanism is arranged in a valve bridge and configured, in a first default operating state, to convey at least the main valve actuation motion and configured, in a first activated state, to lose the main valve actuation motion and the auxiliary valve actuation motion. Additionally, a lost motion adding mechanism is arranged in a rocker arm and configured, in a second default operating state, to lose the auxiliary valve actuation motion and configured, in a second activated state, to convey the auxiliary valve actuation motion, wherein the lost motion adding mechanism is parallel with the lost motion subtracting mechanism in the valve actuation load path at least during the second activated state.

A type II valve train assembly that selectively opens first and second intake valves and first and second exhaust valves is provided. The valve train assembly includes an intake rocker arm assembly and an exhaust rocker arm assembly. The valve train assembly is configurable for operation in any combination of activated and deactivated states of engine braking and cylinder deactivation. The exhaust rocker arm assembly includes a first exhaust rocker arm, a second exhaust rocker arm and an engine brake exhaust rocker arm. A first exhaust HLA is associated with the first exhaust rocker arm. A second exhaust HLA is associated with the second exhaust valve. An exhaust actuation assembly selectively actuates to alter travel of the first and second exhaust HLAs to change a state of cylinder deactivation between activated and deactivated.

An engine brake rocker arm assembly is operable in an engine drive mode and an engine braking mode and selectively opens first and second exhaust valves. The engine brake rocker arm assembly includes an exhaust rocker arm configured to rotate about a rocker shaft, an engine brake capsule assembly movable between (i) a locked position configured to perform an engine braking operation, and (ii) an unlocked position that does not perform the engine braking operation, and a hydraulically controlled actuator assembly configured to selectively move the engine brake capsule assembly between the first and second positions.

Systems for valve actuation in internal combustion engines provide rocker control components in the form of biasing mechanisms for biasing the valve side of a lost motion rocker toward the engine valves. This may prevent gaps in the valvetrain, particularly when used with cams having sub-base circle auxiliary motion event profiles. Valvetrain components, such as an e-foot engaging a valve bridge, may be provided with a biasing mechanism and stroke limiting and retaining components to maintain engagement between the e-foot and valve bridge, to control stability of the valve bridge, and to make assembly/disassembly easier.

A valve actuation system comprises a valve actuation motion source configured to provide a main valve actuation motion and an auxiliary valve actuation motion for actuating at least one engine valve via a valve actuation load path. A lost motion subtracting mechanism is arranged in a pre-rocker arm valve train component and configured, in a first default operating state, to convey at least the main valve actuation motion and configured, in a first activated state, to lose the main valve actuation motion and the auxiliary valve actuation motion. Additionally, a lost motion adding mechanism is arranged in a valve bridge and configured, in a second default operating state, to lose the auxiliary valve actuation motion and configured, in a second activated state, to convey the auxiliary valve actuation motion, wherein the lost motion adding mechanism is in series with the lost motion subtracting mechanism in the valve actuation load path.

A valve mechanism includes a valve, a camshaft, an intermediate swing arm located between a cam and the valve, a lift regulating mechanism and a roller assembly. The cam drives the valve to move by means of the intermediate swing arm. The roller assembly is supported by the cam, an eccentric wheel of the lift regulating mechanism and an intermediate swing arm roller. A peripheral surface of the eccentric wheel includes a lift regulating section having a start point and an end point, a maximum lift point of the lift regulating section is located between the start point and the end point, and the lift regulating section is divided into a first section which is convex and a second section having at least a part thereof concave.

A valve train assembly includes at least a number of exhaust valves; at least one camshaft with at least a pair of a primary lift cam and an engine brake lift cam. A number of rocker arms each include a cam follower for following one of the primary lift cam and the engine brake lift cam. One rocker arm includes a cam follower following an engine brake lift cam. The rocker arm is provided with an engine brake capsule. Various biasing assemblies are disclosed that cooperate with one of the rocker arms of which the cam follower follows an engine brake lift cam to accommodate mechanical lash.