In an internal combustion engine, a linkage is provided between an auxiliary motion source and a main motion load path, such that motions received by the linkage from the auxiliary motion source result in provision of a first force to at least one engine valve and a second force to the main motion load path in a direction toward a main motion source. Where an automatic lash adjuster is associated with the main motion load path, the second force may be selected to aid in the control of lash adjustments made by the automatic lash adjuster. In various embodiments, the linkage may be embodied in an mechanical linkage, whereas in other embodiments, an hydraulic linkage may be employed. The linkage may be incorporated into, or otherwise cooperate, a valve bridge or a rocker arm.

A compact, modular, lost motion variable valve actuation assembly includes a dry start hydraulic circuit to enable quick priming of a lost motion master-slave circuit from a dry start reservoir to the master piston chamber during engine start. Motion of the master piston on engine startup may draw in fluid from the dry start hydraulic circuit. The dry start components may be integrated into a compact modular rocker shaft pedestal package suitable for retrofit on existing engine head assemblies. The master piston may include a push tube interface that includes a deep push tube cavity and lubrication capabilities in the master piston that provides for improved wear, stability, easy installation and alignment. The slave piston may be provided with a valve catch to reduce valve closing velocity during cycles involving lost-motion.

A compact, modular, lost motion variable valve actuation assembly includes a dry start hydraulic circuit to enable quick priming of a lost motion master-slave circuit from a dry start reservoir to the master piston chamber during engine start. Motion of the master piston on engine startup may draw in fluid from the dry start hydraulic circuit. The dry start components may be integrated into a compact modular rocker shaft pedestal package suitable for retrofit on existing engine head assemblies. The master piston may include a push tube interface that includes a deep push tube cavity and lubrication capabilities in the master piston that provides for improved wear, stability, easy installation and alignment. The slave piston may be provided with a valve catch to reduce valve closing velocity during cycles involving lost-motion.

A compression release engine in-cylinder braking system, comprising a valve mechanism, an oil cylinder device, an oil pump device, and an oil supply device. The oil cylinder device and the oil pump device of each air cylinder communicate with each other through a pressure transmission oil circuit, which communicates with the oil supply device through a low-pressure relief valve. An air release valve is arranged at the high end of an oil circuit system. During in-cylinder braking, the air release valve is closed, an electromagnetic reversing valve is energized, engine oil having a pressure of P1 is supplied to the pressure transmission oil circuit, and a cam abuts against and pushes the oil pump device to pump high-pressure oil to the oil cylinder device, so as to push a rocker arm to open a valve, thereby achieving in-cylinder braking.

A compression release engine in-cylinder braking system, comprising a valve mechanism, an oil cylinder device, an oil pump device, and an oil supply device. The oil cylinder device and the oil pump device of each air cylinder communicate with each other through a pressure transmission oil circuit, which communicates with the oil supply device through a low-pressure relief valve. An air release valve is arranged at the high end of an oil circuit system. During in-cylinder braking, the air release valve is closed, an electromagnetic reversing valve is energized, engine oil having a pressure of P1 is supplied to the pressure transmission oil circuit, and a cam abuts against and pushes the oil pump device to pump high-pressure oil to the oil cylinder device, so as to push a rocker arm to open a valve, thereby achieving in-cylinder braking.

The disclosure relates 10 a device which is used to adjust the valve stroke of internal combustion engines and has an actuation element for the valve stem. The actuation element is actuated by the camshaft and has a receiving space for a pressure medium. The receiving space is fluidically connected to a reservoir space of an adjustment reservoir. The volume of the reservoir space can be adjusted by means of a reservoir piston. The reservoir piston is loaded toward the reservoir space with a force that is greater than the force applied by the pressure medium and that is less than the restoring force acting on the piston.

An engine valve lifter assembly comprises a lifter body, a plunger assembly, and a spring. The lifter body comprises an oil control portion comprising an exterior surface, oil ports, and an interior oil chamber. A plunger interface end comprises an interior plunger chamber and a second spring seat. Selectively reciprocating plunger assembly comprises a piston end coupled to reciprocate in the oil chamber and a cam input end comprising a spring seat. A spring is biased between the spring seat and the second spring seat. The spring is configured to push the cam input end away from the plunger chamber. A sleeve is coupled around the oil control portion of the lifter body, and the sleeve is slidable between a lower position and an upper position to selectively block and unblock the oil ports.

A hydraulically variable gas exchange valve train for an internal combustion engine is proposed that includes a hydraulic housing with a pressure chamber, a pressure relief chamber, and a vent duct. The vent duct is connected hydraulically on a housing inner side via a restriction to the pressure relief chamber, and opens on the housing outer side below the pressure relief chamber with regard to a direction of gravity. The vent duct opens into a hydraulic reservoir, wherein the vent duct opening lies below a normal level of the hydraulic reservoir with regard to the direction of gravity.

A four-stroke internal combustion engine is disclosed. A camshaft and a crankshaft if the engine are synchronized to rotate at a same rotational speed. A first linkage arrangement is configured to change the motion of an exhaust valve head. A second linkage arrangement is configured to change the motion of the intake valve head. A control unit is configured for controlling the first linkage arrangement to selectively prevent the motion of the exhaust valve head and for controlling the second linkage arrangement to selectively prevent the motion of the intake valve head.

A four-stroke internal combustion engine is disclosed. A camshaft and a crankshaft if the engine are synchronised to rotate at a same rotational speed. A first linkage arrangement is configured to change the motion of an exhaust valve head. A second linkage arrangement is configured to change the motion of the intake valve head. A control unit is configured for controlling the first linkage arrangement to selectively prevent or reduce the motion of the exhaust valve head and for controlling the second linkage arrangement to selectively prevent or reduce the motion of the intake valve head.