Poppet valves in an internal combustion engine may be operated intermittently if desired by the selective dynamic locking or unlocking of one or more cam lobes with the shaft that acts as a conventional camshaft when the lobes are locked to it. One or more cam lobes with a small radial clearance ride on a shaft so that an engagement mechanism may be activated as needed to lock the cam lobe to the shaft, thus activating the respective poppet valve. The cam lobe is prevented from moving axially to ensure correct alignment with a follower. A suitable holding device may be used to ensure the non-activated cam lobe(s) is (are) restrained at a suitable orientation relative to the cam follower.

Poppet valves in an internal combustion engine may be operated intermittently if desired by the selective dynamic locking or unlocking of one or more cam lobes with the shaft that acts as a conventional camshaft when the lobes are locked to it. One or more cam lobes with a small radial clearance ride on a shaft so that an engagement mechanism may be activated as needed to lock the cam lobe to the shaft, thus activating the respective poppet valve. The cam lobe is prevented from moving axially to ensure correct alignment with a follower. A suitable holding device may be used to ensure the non-activated cam lobe(s) is (are) restrained at a suitable orientation relative to the cam follower.

A variable valve control system may include a variable valve mechanism having latching pins for performing variable valve lift by a pressure difference of oil, an oil control circuit block having a low-pressure oil line and a high-pressure oil line to control ON/OFF of the latching pins, and a rotation shaft valve having oil passages for switching the low-pressure oil line and the high-pressure oil line.

Systems and methods to extend a life of a component of a cylinder deactivation system are provided. A method includes initiating, by a controller, a CDA mode for an engine; determining, by the controller, a first cycle count for a first oil control solenoid of the CDA system; determining, by the controller, a second cycle count for a second oil control solenoid of the CDA system; comparing, by the controller, the first cycle count and the second cycle count; and modifying, by the controller, operation of the CDA mode for the engine based on the comparison.

A variable valve timing assembly for a combustion engine comprises: a phaser configured to receive therein a camshaft; wherein the phaser includes a phaser exterior body that is cylindrical-shaped, a phaser interior body that is cylindrical-shaped and within the phaser exterior body, a phaser exterior spline on an exterior of the phaser exterior body, and a phaser interior spline on an exterior of the phaser interior body; a phaser inner housing disposed within the phaser and configured to receive therein the camshaft; wherein the phaser inner housing includes an inner housing interior spline that mates with the phaser interior spline; an advancing chamber configured to receive fluid from and discharge fluid to the camshaft; a retarding chamber configured to receive fluid from and discharge fluid to the camshaft; and a main housing that encloses therein the phaser and the phaser inner housing, and is configured to engage a timing chain/belt.

A system for controlling a variable valve apparatus may include a plurality of oil control valves (OCVs) configured to respectively supply oil from an oil pump to a plurality of variable valve apparatuses or block the supply of the oil, and a single relief valve coupled to the plurality of oil control valves, wherein pressure in a plurality of control galleries for providing an oil supply path from the plurality of oil control valves to the plurality of variable valve apparatuses is maintained constant by only the single relief valve.

A hydraulic lash adjuster for an engine valve train has a hydraulic lash adjusting arrangement for automatically compensating for lash in an engine valve train, and a lost motion arrangement for inhibiting motion induced in the valve train in response to a lift profile of a rotating cam from being transferred to an engine valve.

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.

A system for controlling a variable valve apparatus may include a plurality of oil control valves (OCVs) configured to respectively supply oil from an oil pump to a plurality of variable valve apparatuses or block the supply of the oil, and a single relief valve coupled to the plurality of oil control valves, wherein pressure in a plurality of control galleries for providing an oil supply path from the plurality of oil control valves to the plurality of variable valve apparatuses is maintained constant by only the single relief valve.

A variable valve actuation device includes a plurality of valve lifter. Each valve lifter slidable in a lifter support hole between an upper position and a lower position. A valve rest recess communicating with a valve rest chamber opens out at an outer circumferential surface of the valve lifter, and a valve rest supply port of a valve rest passage opens out at an inner circumferential surface of the lifter support hole in such a positional relationship that the valve rest passage and the valve rest chamber communicate with each other when the valve lifter is at the upper position, and continue to communicate with each other until the valve lifter has moved downward to a shut-off position located at a prescribed part of a down stroke from the upper position. The communication between the valve rest passage and the valve rest chamber shut off at the shut-off position.