A compression release type engine brake includes a first opening unit and a second opening unit each including an exhaust rocker arm, an adjusting screw provided at an end portion of the exhaust rocker arm, a brake module in which brake oil is selectively and a brake piston mount portion is formed therein, a brake piston which is selectively protruded according to the oil supply inside the brake module, a reset member selectively exhausting the oil in the brake module, and a valve bridge connected to the brake piston and provided with an exhaust valve, and wherein a rocker arm protrusion is formed in the exhaust rocker arm of at least one of the first opening unit and the second opening unit, and the shaft spring presses the rocker arm protrusion and adjusts a distance between the first opening unit and the second opening unit.

Hydraulic systems in an engine valvetrain having lost motion and/or braking hydraulic circuits are provided with a conditioning circuit that may include a supplemental supply passage, which provides continuous and supplemental supply of hydraulic fluid from a supply source to the braking and lost motion circuits, as well as a venting of the circuits to ambient, such that the hydraulic fluid in these circuits is kept in a refreshed and conditioned state without air contamination. A vented three-way solenoid valve may be utilized. The supplemental supply passage may be provided at various locations in the valvetrain and in the engine head environment. The supplemental supply passage may include flow and pressure control devices to control the flow of the supplemental supply of hydraulic fluid.

An engine valve actuating apparatus includes a housing that contains an activation piston bore and an actuation piston bore. The activation piston is disposed in the activation piston bore and configured to actuate an engine valve. The actuation piston includes at least one side surface that is in sliding contact with the inner surface of the actuation piston bore so that the actuation piston can slide within the actuation piston bore. The actuation piston also has a guide mechanism, which guides the first and second links to move in a plane between the first position and the second position. At least a part of the guide mechanism is below at least a part of the at least one side surface of the actuation piston.

An engine valve actuating apparatus includes a housing that contains an activation piston bore and an actuation piston bore. The activation piston is disposed in the activation piston bore and configured to actuate an engine valve. The actuation piston includes at least one side surface that is in sliding contact with the inner surface of the actuation piston bore so that the actuation piston can slide within the actuation piston bore. The actuation piston also has a guide mechanism, which guides the first and second links to move in a plane between the first position and the second position. At least a part of the guide mechanism is below at least a part of the at least one side surface of the actuation piston.

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.

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.

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 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 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.