A valvetrain for an internal combustion engine includes a camshaft, an electromagnetic latch assembly, a rocker shaft, and a rocker arm assembly. The rocker arm assembly may include a cam follower configured to engage a cam mounted on the camshaft as the camshaft rotates and a rocker arm configured to rotate on the rocker shaft. The electromagnetic latch assembly may include a pin translatable between a first position and a second position and an electromagnet that causes the pin to actuate. The movement of the pin may provide mode switching for a switching rocker arm, a cylinder deactivating rocker arm, or an engine brake rocker arm. The electromagnet is powered by a circuit that passes through the rocker shaft. The electromagnet may be mounted to the rocker shaft. Running the circuit through the rocker shaft allows the electromagnet to be powered with wiring that remains stationary.

A lift-valve assembly, comprising a lift valve within a housing that includes a pressure segment, a mounting segment, a port segment, and a seat segment. The lift-valve assembly may receive a lift valve, and the housing including a valve seat and a biasing spring in a selectively replaceable configuration suitable for use in a conventional internal combustion engine in place of the conventional individual components, actuated by a cam actuating system, and controlling fluid communication between a combustion chamber and both intake and exhaust systems.

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.

A system for monitoring operation of an internal combustion engine having a rocker arm assembly for actuating an engine valve is disclosed. The rocker arm assembly includes a first arm with a first end and a second end, at least one slider pad connected to the first arm near the second end of the first arm, a second arm also having a first end pivotally connected near the first end of the first arm along a pivot axle, a latch that when latched secures the first arm relative to the second arm in a latched mode, and when unlatched allows the first arm to move relative to the second arm in an unlatched mode. The system also employs a sensor attached to one of the arms that can detect when the arms are moving relative to each other, and adapted to provide a signal indicating the detected movement.

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 HLA's to change a state of cylinder deactivation between activated and deactivated.

The invention relates to a reciprocating-piston machine, comprising a valve actuation device for at least one gas exchange valve, at least one valve stroke transmission device, which has at least one valve stroke transmission element, which is arranged between the gas exchange valve and the camshaft and which is mounted for movement between a first Position associated with a closed Position of the gas exchange valve and a second Position associated with an open position of the gas exchange valve, at least one halting device having a halting element mounted for movement between an actuation position and a release position in a machine housing or a housing-fixed component parallel to a guiding surface of the first valve stroke transmission element that the halting element at least shows the displacement motion of the first valve stroke transmission element and releases said displacement motion in the release position.

A variable-stroke valve drive includes a double leg spring with a first spring leg and a second spring leg in a cylinder head of an internal combustion engine and a pivot lever. The pivot lever is supported on a guideway track of a guideway by a rolling element having a pivot point and the pivot lever, by way of a control track, is supported so as to be clearance-free on an intermediate element to a charge-cycle valve. The pivot lever is pivotable by a cam of a cam shaft for adjusting a stroke and the pivot point is displaceable parallel to the guideway track by an adjustment installation for adjusting a stroke height. The double leg spring in a central region forms an intermediate leg. A respective end of the first and second spring legs is formed to be largely parallel to a longitudinal axis of the double leg spring.

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.

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.

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.