A sliding cam system for an internal combustion engine. The sliding cam system includes a cam shaft and a cam carrier, arranged rotationally fixedly and axially movably on the cam shaft. The cam carrier including a first shifting gate and a second shifting gate. The sliding cam system includes a first actuator with an element able to move along a longitudinal axis of the cam shaft, especially a pin, which can be brought into contact with the first shifting gate for the axial movement of the cam carrier in a first direction. The sliding cam system includes a second actuator with an element able to move along the longitudinal axis of the cam shaft, especially a pin, which can be brought into contact with the second shifting gate for the axial movement of the cam carrier in a second direction which is opposite to the first direction.

An engine variable valve operating apparatus includes a cam switching mechanism having a switching drive shaft. When the switching drive shaft is longitudinally moved, a cam mechanism advances and retracts a switching pin. When the switching pin is advanced to engage in a lead groove formed around a cam carrier and the cam carrier is axially moved while rotating, cam lobes around the cam carrier are switched to act on an engine valve. An actuator for the switching drive shaft includes an actuator drive body which is linearly reciprocally movable and is coupled to a longitudinal end of the switching drive shaft to axially move the same. The above arrangement enables the cam switching mechanism and the actuator mechanism to be simple and compact in structure for preventing the engine from becoming large in size.

A control system for a hydraulic variable valve. The control system may include an OCV configured with a housing, a flow passage defined in the housing, a main port, first and second drain ports, a spool, and a relief valve; a main line connecting the main port and the oil pump to each other; a control line connecting the control port and the lash adjuster to each other; an orifice provided between the main line and the control line; and a controller controlling the OCV to allow at least one combination of the main port and the first drain port, the control port and the second drain port, and the main port and the control port to communicate with each other.

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.

Systems for valve actuation in internal combustion engines provide configurations for hydraulic lash adjusters and valve actuation valvetrain components that are particularly suitable for prevention of HLA jacking in lost motion cam environments and in valve bridge environments. In one implementation, a rocker arm may transmit motion from a lost motion cam having main event and auxiliary event lobes. Main event motion is transmitted to two engine valves through the rocker arm, a lash adjuster, lash adjuster loading component and valve bridge, which define part of a first load path. Braking motion is transmitted to one of the engine valves through an inboard valve actuator and bridge pin, which define part of a second load path. The HLA is thus disposed in a separate load path from the braking valve load and the lash adjuster loading component keeps the lash adjuster under a constant compressive force to prevent jacking.

Methods and systems are provided for removing entrapped air from oil flowing within a valve deactivation hydraulic circuit of an engine. In one example, the system may include a cylinder head cap, a variable displacement engine oil control valve (VDE OCV), a variable control timing oil control valve (VCT OCV), a rocker arm, a switch of the rocker arm, a pressure relief valve and a switch of the pressure relief valve, the cylinder head cap having an inbound interior surface of the cylinder head cap, the valve deactivation hydraulic circuit having a switching gallery and a hydraulic lash adjuster oil gallery. The hydraulic lash adjuster oil gallery may provide oil pressure communication to the switching gallery, the hydraulic lash adjuster oil gallery, the switch of the rocker arm, the switch of the pressure relief valve, the VDE OCV, and the VCT OCV.

A valve drive for an internal combustion engine may include a camshaft, at least one cam follower, and at least one adjusting device. The camshaft may include at least one cam group including a first cam and a second cam. The at least one adjusting device may include a first adjustable engagement element configured to contact a first guide and a second adjustable engagement element configured to contact a second guide of a slotted guide The at least one adjusting device may further include a stop arrangement axially shiftable relative to a rocker lever shaft. The stop arrangement may include a first stop region and a second stop region. At least one of the first engagement element and the second engagement element may be adjustable via the first stop region and the second stop region, respectively, when the stop arrangement is shifted along the rocker lever shaft.

A variable valve operating device for an internal combustion engine includes a cam carrier supported on a camshaft and shifting switching pins that are advanced into and retracted out of shift lead grooves defined in the cam carrier. The shift lead grooves include shift groove side walls having shift groove side wall surfaces from shift starting inflection regions of the cam carrier to shift ending inflection regions thereof. The shift groove side walls include particular shift groove side walls extending from axial positions of the shift starting inflection regions toward shift intermediate regions and also extending from circumferential positions of the shift intermediate regions disposed between the shift starting inflection regions and the shift ending inflection regions toward the shift starting inflection regions. The side walls have slanted outer circumferential surfaces extending from the circumferential positions progressively deeper toward groove bottom surfaces and reaching the shift starting inflection regions.

Methods and systems are provided for an engine oil system of a cylinder head. In one example, an engine oil system may include a first oil gallery and a second oil gallery fluidly coupled to each other via a plurality of oil chambers. Each oil chamber includes a plug, and one or more of the plugs may include a slot shaped to direct a flow of engine oil from a solenoid valve to the second oil gallery.

Systems for valve actuation in internal combustion engines provide configurations for collapsing valve train components, particularly collapsing valve bridges. Various configurations for locking a bridge piston to a bridge housing include substantially cylindrical locking pins that may be housed within a substantially cylindrical receptacles defined by a transverse bore in the bridge piston and actuated hydraulically and may include an actuating pin that interacts with the locking pins to synchronize motion and provide positive positioning within an annular recess in the bridge housing to lock or unlock the bridge piston for movement relative to the bridge housing. Various geometries for locking pins and actuating pins provide benefits of manufacturing, ease of assembly, alignment and reduced wear.