A hydraulic valve actuation system (30) and a method of assembly can include a plurality of hydraulically actuatable valves (34a, 34b, 34c, 34d, 134a, 134b, 134c, 134d) operably associated with an internal combustion engine (86) having a crankshaft (50) rotatable about a longitudinal axis. The actuation system (30) can include at least one cam lobe (52) mounted on or integrally formed with the crankshaft for rotation with the crankshaft (50). At least one fluid piston pump (36, 36a, 36b) connected to the at least one cam lobe (52) for generating a reciprocating fluid flow in response to rotation of the at least one cam lobe (52). At least one hydraulically actuated valve (34a, 34b, 34c, 34d, 134a, 134b, 134c, 134d) in fluid communication with the reciprocal fluid flow generated by the at least one fluid piston pump (36, 36a, 36b) to drive the valve (34a, 34b, 34c, 34d, 134a, 134b, 134c, 134d) to be controlled toward an open position.

Described herein is a system for variable actuation of an engine valve of an internal-combustion engine, where the system is able to actuate the engine valves, selectively, in a four-stroke operating mode and in a two-stroke operating mode, on the basis of the operating conditions of the engine.

Described herein is a system for variable actuation of an engine valve of an internal-combustion engine, where the system is able to actuate the engine valves, selectively, in a four-stroke operating mode and in a two-stroke operating mode, on the basis of the operating conditions of the engine.

A variable valve timing device for an engine utilizing hydraulically actuated valves. A cam follower block, complete with radial bores, and cam followers within these bores, is pivotally mounted about a rotating camshaft. The rotating camshaft displaces the cam followers within the bores, causing the followers to displace hydraulic fluid, forcing movement of either, an intake or exhaust valve, by hydraulic force on a secondary hydraulic cylinder. The cam follower block angular position about the camshaft is mechanically adjustable during operation. Separate cam follower blocks are used for intake and exhaust valve operation such that the valve timing of the intake and exhaust valves can be changed independently.

An electro-hydraulic variable valve lift system includes a medium pressure chamber, a high pressure circuit, a valve, a pump and an actuator. The chamber is formed in a cylinder head assembly and is in fluid communication with a hydraulic fluid source. The high pressure circuit is positioned in the cylinder head assembly and is in selective fluid communication with the chamber. The valve is in fluid communication with the chamber and the high pressure circuit, and the pump is configured to pump hydraulic fluid in the high pressure circuit. The actuator is in fluid communication with the pump, control valve and high pressure circuit, and is in engagement with an intake valve. The chamber and the actuator are each positioned in the cylinder head assembly at a location above the valve such that during an engine shutdown event, hydraulic fluid is retained in the chamber and the valve.

An engine control system coordinates control of a pressure regulating mechanism associated with a turbocharger turbine and control of a variable valve actuating (VVA) mechanism for expanding the range of possible exhaust gas recirculation rates over a large portion of an engine operating map to provide EGR rates which are greater than typical present-day levels while mitigating engine pumping losses by causing the turbocharger to operate with better efficiency in some regions of the map where it otherwise would not. Turbocharger efficiency is improved by controlling the VVA mechanism to set the timing of operation of its respective cylinder valves in accordance with a predetermined correlation of operating efficiencies of a compressor to timing of operation of respective engine cylinder valves, causing the compressor to operate at points of better efficiency than it otherwise would without use of VVA.

A valve actuator system is capable of operating a number of valves with a single cam. The system includes a power shaft, a cam mounted around the power shaft and a gear train to drive the cam when the shaft rotates. Hydraulic actuator assemblies corresponding to the number of valves are radially positioned around the shaft axis for operation by the cam. Hydraulic tubes connect each actuator to a valve follower disposed adjacent to the respective valves. The cam profile pressing each actuator plunger in sequence as the cam rotates causes the hydraulic fluid to flow out of the actuator assembly, through the like-numbered pipe, and into the like-numbered follower assembly, which in turn causes the follower plunger to move the like-numbered valve from an open position or a closed position. This occurs sequentially for each valve.

A valve train component for conveying valve actuation motions within an internal combustion engine is provided, which valve train component comprises a body member having a bore formed therein; a sliding member disposed in the bore; and an overload feature operatively connected to the body member and the sliding member. The overload feature is configured to not yield when a load placed on the overload feature is less than a load threshold, thereby preventing movement of the sliding member into the bore, and to yield when a load placed on the overload feature meets or exceeds the load threshold, thereby permitting movement of the sliding member into the bore such that at least a portion of the valve actuation motions is not conveyed by the valve train component.

A valve train component for conveying valve actuation motions within an internal combustion engine is provided, which valve train component comprises a body member having a bore formed therein; a sliding member disposed in the bore; and an overload feature operatively connected to the body member and the sliding member. The overload feature is configured to not yield when a load placed on the overload feature is less than a load threshold, thereby preventing movement of the sliding member into the bore, and to yield when a load placed on the overload feature meets or exceeds the load threshold, thereby permitting movement of the sliding member into the bore such that at least a portion of the valve actuation motions is not conveyed by the valve train component.