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.

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.

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.

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.

A method of manufacturing a bearing pin with an external lubrication channel and the bearing pin formed thereby are disclosed. The method includes fixing a rotational orientation of the bearing pin along a pin axis, cutting an outer surface of the bearing pin in a first straight line across a first convex portion thereof to create a first open external groove of the lubrication channel; and cutting an outer surface of the bearing pin in a second straight line across a second convex portion thereof to create a second open external groove of the lubrication channel. The grooves have a concave sectional profile and circumferential open ends disposed intermediate and not intersecting the ends of the bearing pin.

A compression release engine in-cylinder braking system, comprising a valve mechanism (I), an oil cylinder device (III), an oil pump device (II), and an oil supply device (IV). The oil cylinder device (III) and the oil pump device (II) of each air cylinder communicate with each other through a pressure transmission oil circuit (L). The pressure transmission oil circuit (L) communicates with the oil supply device (IV) through a low-pressure relief valve (90). An air release valve (200) is arranged at the high end of an oil circuit system. During in-cylinder braking, the air release valve (200) is closed, an electromagnetic reversing valve (80) is energized, engine oil having a pressure of P1 is supplied to the pressure transmission oil circuit (L), and a cam (16) abuts against and pushes the oil pump device (II) to pump high-pressure oil to the oil cylinder device (III), so as to push a rocker arm (12) to open a valve (10), thereby achieving in-cylinder braking. During non-in-cylinder braking, the air release valve (200) is opened, the electromagnetic reversing valve (80) is de-energized, engine oil having a pressure of P2 is supplied to the pressure transmission oil circuit (L), P1 is greater than P2, the oil cylinder device (III) and the oil pump device (II) return respectively, and the cam (16) is out of contact with the oil pump device (II). The compression release engine in-cylinder braking system works stably and reliably, has a simple oil circuit, and is not restricted by the number of engine cylinders.

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.

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.