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 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.

Several devices are disclosed that can be usable together or used in other valvetrains. Disclosed herein are a rocker arm assembly, compliance capsules for a switchable capsule of the rocker arm, actuators, and support structures for the actuators. The alternative compliance capsules can be electromechanically actuated by the alternative actuators, which are hung over the rocker shaft by the support structure. A cam actuator can be in addition to an overhead cam rail and in addition to the rocker shaft. The cam actuator can be configured with a compliance capsule so that the switching of the switchable capsule is mechanically linked and less reliant on precise electrical signal timing.

A rocker arm assembly can comprise a rocker tube configured to be positioned around a rocker shaft, the rocker tube comprising a retention mechanism. A first rocker arm can be press-fit to the rocker tube. A second rocker arm can be pivotably mounted around the rocker tube and retained on the rocker tube by the retention mechanism. An alternative rocker arm assembly, that can be combined with the first rocker arm assembly, can comprise a first and second rocker am and a plate fixed to the first rocker arm. The plate can comprise an extension extending over the second rocker arm. A lost motion spring can be installed between the second rocker arm and the extension.

A rocker arm assembly can comprise a rocker tube configured to be positioned around a rocker shaft, the rocker tube comprising a retention mechanism. A first rocker arm can be press-fit to the rocker tube. A second rocker arm can be pivotably mounted around the rocker tube and retained on the rocker tube by the retention mechanism. An alternative rocker arm assembly, that can be combined with the first rocker arm assembly, can comprise a first and second rocker am and a plate fixed to the first rocker arm. The plate can comprise an extension extending over the second rocker arm. A lost motion spring can be installed between the second rocker arm and the extension.

A rocker assembly for a type III center pivot valvetrain comprises a rocker arm comprising a cam end, a center pivot bore, and a valve end. The valve end comprises a first actuator bore and a second actuator bore. A cylinder deactivation actuator is in the first actuator bore. An engine brake actuator is in the second actuator bore. The rocker assembly can be part of a valve assembly and can impart an engine braking function, a cylinder deactivation function, and a main lift function to first and second valves. It is also possible to impart an early exhaust valve opening, a main lift function, and a late exhaust valve closing to the engine braking valve.

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.

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.

A novel latch seat for a switching rocker arm assembly used in variable valve actuation (VVA) systems for internal combustion engines. The seat is formed interactively in the assembled switching rocker arm using a novel fixture and press. The press interactively creates a curved dimple of the correct curvature, position and depth while measuring several lash dimensions. Since the latch seat is formed on the assembled rocker arm assembly, the latch seat depth is designed to account for the inaccuracies in the rocker arm assembly parts which create lash. Therefore all of the parts may be made with less precision since the latch seat is sized to compensate for the inaccuracies of all of the parts. The rocker arm assembly parts now may be manufactured to less stringent standards, but result in a rocker arm assembly with same accuracy of rocker arm assemblies manufactured to previous standards.