An actuating system of an engine valve comprises a movable member, for example, in the form of a master piston controlled by a cam of a camshaft. A slave piston is hydraulically controlled by the master piston by means of a volume of pressurized fluid, to open said engine valve against the action of a return spring. The system also comprises an auxiliary device for applying an additional force to the engine valve to keep the engine valve in a closed position. The auxiliary device is configured or controlled in such a way that the total force tending to keep the engine valve in its closed position varies during each rotation cycle of the cam. The total force is higher at least in one part of the rotation cycle of the cam wherein the engine valve must remain in its closed position, and is, instead, reduced at least in one part of the rotation cycle of the cam wherein the engine valve is not in its closed position.

An actuating system of an engine valve comprises a movable member, for example, in the form of a master piston controlled by a cam of a camshaft. A slave piston is hydraulically controlled by the master piston by means of a volume of pressurized fluid, to open said engine valve against the action of a return spring. The system also comprises an auxiliary device for applying an additional force to the engine valve to keep the engine valve in a closed position. The auxiliary device is configured or controlled in such a way that the total force tending to keep the engine valve in its closed position varies during each rotation cycle of the cam. The total force is higher at least in one part of the rotation cycle of the cam wherein the engine valve must remain in its closed position, and is, instead, reduced at least in one part of the rotation cycle of the cam wherein the engine valve is not in its closed position.

A valvetrain for an internal combustion engine includes a camshaft and a rocker arm assembly. The rocker arm assembly includes an electrical device, a rocker arm, and a cam follower. A contact held to the rocker arm abuts a spring attached to a component distinct from the rocker arm assembly to form an interface. The electrical device is powered through the interface. The spring slides over the contact as the rocker arm assembly pivots to actuate a moveable valve. The interface is formed near a pivot axis whereby the motion undergone by the interface is much less than the motion undergone by points on the rocker arm assembly more distal from the axis. Keeping the interface proximate the pivot axis and leaving the spring free to slide over the contact reducing the extent to which the spring undergoes movement and wear during valvetrain operation.

A valvetrain for an internal combustion engine includes a camshaft and a rocker arm assembly. The rocker arm assembly includes an electrical device, a rocker arm, and a cam follower. A contact held to the rocker arm abuts a spring attached to a component distinct from the rocker arm assembly to form an interface. The electrical device is powered through the interface. The spring slides over the contact as the rocker arm assembly pivots to actuate a moveable valve. The interface is formed near a pivot axis whereby the motion undergone by the interface is much less than the motion undergone by points on the rocker arm assembly more distal from the axis. Keeping the interface proximate the pivot axis and leaving the spring free to slide over the contact reducing the extent to which the spring undergoes movement and wear during valvetrain operation.

In a tappet with a built-in lash adjuster, hydraulic oil is prevented from leaking from a low pressure chamber during a long-period stop.

A tappet (10) includes a hydraulic lash adjuster (11) which supports a lower end portion of a push rod (96) and a tappet case (12) to which the lash adjuster (11) is internally fitted and which is reciprocally displaced in a vertical direction according to a rotating cam (85). An inner peripheral surface of the tappet case (12) is provided with an air-vent passage (34) through which air existing between the tappet case (12) and the lash adjuster (11) can be discharged upward when the lash adjuster (11) is being assembled.

In a tappet with a built-in lash adjuster, hydraulic oil is prevented from leaking from a low pressure chamber during a long-period stop.

A tappet (10) includes a hydraulic lash adjuster (11) which supports a lower end portion of a push rod (96) and a tappet case (12) to which the lash adjuster (11) is internally fitted and which is reciprocally displaced in a vertical direction according to a rotating cam (85). An inner peripheral surface of the tappet case (12) is provided with an air-vent passage (34) through which air existing between the tappet case (12) and the lash adjuster (11) can be discharged upward when the lash adjuster (11) is being assembled.

This disclosure relates to a hydraulic support element for a switchable rocker arm of a valve train of an internal combustion engine. The hydraulic support element includes a cup-shaped cylinder, within which a hollow piston is arranged in an axially displaceable manner. The piston includes a filter cartridge which is in the form of a hollow body and can be charged from the outside with pressurized oil and an interior space of which is connected to an outlet opening of the contact head. An interior space of the piston has two pressurized oil chambers, including a first pressurized oil chamber above the piston head and connected to a first pressurized oil feed, and a second pressurized oil chamber formed under the contact head and connected to a second pressurized oil feed. The filter cartridge is tubular and located in the second pressurized oil chamber.

This disclosure relates to a hydraulic support element for a switchable rocker arm of a valve train of an internal combustion engine. The hydraulic support element includes a cup-shaped cylinder, within which a hollow piston is arranged in an axially displaceable manner. The piston includes a filter cartridge which is in the form of a hollow body and can be charged from the outside with pressurized oil and an interior space of which is connected to an outlet opening of the contact head. An interior space of the piston has two pressurized oil chambers, including a first pressurized oil chamber above the piston head and connected to a first pressurized oil feed, and a second pressurized oil chamber formed under the contact head and connected to a second pressurized oil feed. The filter cartridge is tubular and located in the second pressurized oil chamber.

A valve train assembly having a valve train carrier including a body having a cartridge cavity formed in the body, a hydraulic lash adjuster adjustment (HLA) assembly, and a cartridge removably disposed in the cartridge cavity. The cartridge includes a main body defining an inner bore, wherein the HLA assembly is disposed in the inner bore, and the cartridge is sized and shaped for insertion into the cartridge cavity formed in an underside of the valve train carrier. The cartridge is configured to have a valve train lash set prior to insertion into the cartridge cavity. A rocker arm assembly includes a body configured to engage the hydraulic lash adjustment (HLA) assembly, an end having a socket formed therein, and an e-foot extending through the socket and coupled to the end, the e-foot configured to maintain substantially flat contact with a top surface of an engine valve.

A valve train assembly having a valve train carrier including a body having a cartridge cavity formed in the body, a hydraulic lash adjuster adjustment (HLA) assembly, and a cartridge removably disposed in the cartridge cavity. The cartridge includes a main body defining an inner bore, wherein the HLA assembly is disposed in the inner bore, and the cartridge is sized and shaped for insertion into the cartridge cavity formed in an underside of the valve train carrier. The cartridge is configured to have a valve train lash set prior to insertion into the cartridge cavity. A rocker arm assembly includes a body configured to engage the hydraulic lash adjustment (HLA) assembly, an end having a socket formed therein, and an e-foot extending through the socket and coupled to the end, the e-foot configured to maintain substantially flat contact with a top surface of an engine valve.