Abstract: A valve train system for an internal combustion engine includes an exhaust valve moveable between an exhaust closed position and an exhaust open position. A camshaft includes a main exhaust lobe for moving the exhaust valve between the exhaust closed position and the exhaust open position for expelling exhaust constituents from the combustion chamber and an exhaust rebreath lobe for moving the exhaust valve between the exhaust closed position and the exhaust open position for allowing exhaust constituents into the combustion chamber. A two-step device is provided for transmitting motion from the camshaft to the exhaust valve and is switchable between a motion transmitting position and a motion preventing position such that the motion transmitting position allows motion to be transmitted from the exhaust rebreath lobe to the exhaust valve and the motion preventing position prevents motion from being transmitted from the exhaust rebreath lobe to the exhaust valve.

Abstract: A mechanism for compensating systematic uni-directional torque bias imposed on a bi-directional drive actuator shaft, comprising a pallet disposed on an arm for rotation with the actuator shaft. A bucket tappet is engaged by the pallet and contains a helical compression spring. As the actuator shaft rotates and compresses the spring, the load on the pallet increases linearly but the length of the lever arm changes non-linearly at a rate different from the force applied to the pallet. This results in a non-linear torque about the actuator shaft. The torque can be the same at the compression spring preload state as it is at the full load state or it can be biased to be unsymmetrical based on the layout and size of the components and the stroke of the actuator shaft.

Abstract: A valve train system for an internal combustion engine includes an exhaust valve moveable between an exhaust closed position and an exhaust open position. A camshaft includes a main exhaust lobe for moving the exhaust valve between the exhaust closed position and the exhaust open position for expelling exhaust constituents from the combustion chamber and an exhaust rebreath lobe for moving the exhaust valve between the exhaust closed position and the exhaust open position for allowing exhaust constituents into the combustion chamber. A two-step device is provided for transmitting motion from the camshaft to the exhaust valve and is switchable between a motion transmitting position and a motion preventing position such that the motion transmitting position allows motion to be transmitted from the exhaust rebreath lobe to the exhaust valve and the motion preventing position prevents motion from being transmitted from the exhaust rebreath lobe to the exhaust valve.

Abstract: A mechanism for compensating systematic uni-directional torque bias imposed on a bi-directional drive actuator shaft, comprising a pallet disposed on an arm for rotation with the actuator shaft. A bucket tappet is engaged by the pallet and contains a helical compression spring. As the actuator shaft rotates and compresses the spring, the load on the pallet increases linearly but the length of the lever arm changes non-linearly at a rate different from the force applied to the pallet. This results in a non-linear torque about the actuator shaft. The torque can be the same at the compression spring preload state as it is at the full load state or it can be biased to be unsymmetrical based on the layout and size of the components and the stroke of the actuator shaft.

Abstract: A continuously variable valve duration system including a rocker assembly acted upon by two off-spaced camshafts for selectively varying the closing point of a valve in an internal combustion engine. An opening camshaft is rotatably driven by the engine crankshaft and controls at least the opening and point of the valve through a rocker assembly disposed on a fixed pivot shaft. A closing camshaft, rotatably connected to the opening intake camshaft through a cam phaser, is poised to take over control of the valve closing event through the same rocker assembly. By changing the rotational phase of the closing camshaft relative to the opening camshaft via the cam phaser, the valve closing event can be either retarded or advanced so as to override the opening camshaft and thus selectively vary the valve event duration.

Abstract: A variable valve actuation system having a crank-based eccentric transmission driven by an electric motor to control valve lift, duration, and phasing in the cylinder head of an internal combustion engine. A rocker sub-assembly for each valve is pivotably disposed on a pivot shaft between the camshaft and the roller finger follower roller. A primary control crankshaft includes the pivot shaft and is itself rotated about its axis by a connecting rod driven by a motorized secondary crank mechanism to displace the rocker sub-assembly pivot shaft along an arcuate path to change the angular relationship of the rocker sub-assembly to the camshaft, thus changing the valve opening and closing timing and valve lift.

Abstract: A continuously variable valve duration system including a rocker assembly acted upon by two off-spaced camshafts for selectively varying the closing point of a valve in an internal combustion engine. An opening camshaft is rotatably driven by the engine crankshaft and controls at least the opening and point of the valve through a rocker assembly disposed on a fixed pivot shaft. A closing camshaft, rotatably connected to the opening intake camshaft through a cam phaser, is poised to take over control of the valve closing event through the same rocker assembly. By changing the rotational phase of the closing camshaft relative to the opening camshaft via the cam phaser, the valve closing event can be either retarded or advanced so as to override the opening camshaft and thus selectively vary the valve event duration.

Abstract: A system for continuously varying actuation of a valve in an internal combustion engine including a first cam for opening the valve, a second cam for closing the valve, and an oscillating rocker arm continuously engaging each of the first cam, the second cam, and the valvetrain, with the aid of a lost motion spring. The cams are disposed on first and second camshafts that are geared together. The first camshaft gear is driven by the engine crankshaft and thus is phase-invariant. The second camshaft gear is rotationally mounted on the second camshaft and supports the stator of a camshaft phaser. The phaser rotor is mounted to the second camshaft. Varying the rotor position varies the phase of the second cam and thus varies lift and closing timing of the valve. The system is useful in improving the performance of both spark-ignited and compression-ignited engines.