Abstract: A system for varying actuation of a combustion valve in an internal combustion engine, including a control shaft pivot housing fixedly disposed on the engine, a control shaft pivotably disposed within the control shaft pivot housing and eccentrically fixed to a control shaft disc, an input rocker subassembly pivotably disposed on the control shaft disc and having a contact feature disposable as a follower against a camshaft lobe, an output cam subassembly pivotably disposed on the control shaft and engageable by the input rocker subassembly and including an output cam profile for engaging a finger follower of the engine, and a bias spring to urge the output cam subassembly toward the input rocker subassembly. In one aspect of the invention, high lift events with full duration are produced whenever the control shaft is aligned such that the input rocker pivot center and the output cam pivot center are coincidental.

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 system for varying actuation of a combustion valve in an internal combustion engine, including a control shaft pivot housing fixedly disposed on the engine, a control shaft pivotably disposed within the control shaft pivot housing and eccentrically fixed to a control shaft disc, an input rocker subassembly pivotably disposed on the control shaft disc and having a contact feature disposable as a follower against a camshaft lobe, an output cam subassembly pivotably disposed on the control shaft and engageable by the input rocker subassembly and including an output cam profile for engaging a finger follower of the engine, and a bias spring to urge the output cam subassembly toward the input rocker subassembly. In one aspect of the invention, high lift events with full duration are produced whenever the control shaft is aligned such that the input rocker pivot center and the output cam pivot center are coincidental.

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: An electromechanical VVA system for controlling the poppet valves in the cylinder head of an internal combustion engine. The system varies valve lift, duration, and phasing in a dependent manner for one or more banks of engine valves. A rocker subassembly for each valve is pivotably disposed in roller bearings on a rocker pivot shaft between the camshaft and a roller follower. A control shaft supports the rocker pivot shaft for controlling a plurality of rocker subassemblies mounted in roller bearings for a plurality of engine cylinders. The control shaft rotates about its axis to displace the rocker pivot shaft and change the angular relationship of the rocker subassembly to the camshaft, thus changing the valve opening, closing, lift and duration. An actuator attached to the control shaft includes a worm gear drive for positively rotating the control shaft.

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: An electromechanical VVA system for controlling the poppet valves in the cylinder head of an internal combustion engine. The system varies valve lift, duration, and phasing in a dependent manner for one or more banks of engine valves. A rocker subassembly for each valve or valve pair is pivotably disposed on a control shaft between the camshaft and the roller finger follower. The control shaft may be displaced about a pivot axis outside the control shaft to change the angular relationship of the rocker subassembly to the camshaft, thus changing the valve opening, closing, and lift. A plurality of control shafts for controlling all valvetrains in an engine bank defines a control shaft assembly. The angular positions of the individual control shafts may be tuned to optimize the valve timing of each cylinder. The system is applicable to the intake and exhaust camshafts of diesel and gasoline engines.

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.

Abstract: A variable valve actuation mechanism includes a control shaft assembly and a body. The control shaft assembly is pivotable relative to a pivot axis. The body is pivotally disposed on the control shaft assembly, and includes an input cam follower and at least one output cam surface. The input cam follower engages an input cam lobe, and the output cam surface engages a corresponding output cam follower. A spring engages the body and biases the input cam follower into engagement with the input cam lobe.

Abstract: A variable valve actuation mechanism includes a control shaft assembly and a body. The control shaft assembly is pivotable relative to a pivot axis. The body is pivotally disposed on the control shaft assembly, and includes an input cam follower and at least one output cam surface. The input cam follower engages an input cam lobe, and the output cam surface engages a corresponding output cam follower. A spring engages the body and biases the input cam follower into engagement with the input cam lobe.

Abstract: A variable valve train device for installation in an internal combustion engine to controllably vary the intake valve lift, open duration, and timing. A rotary camshaft has a cam lobe for rotation in timed relationship to the motion of the pistons of the engine. A close-fitting frame is rotationally disposed on the camshaft and is pivotably connected to a control shaft such that the angular orientation of the frame may be controlled with respect to the camshaft. A rocker arm disposed on the frame is provided with an input roller which follows the lobe of the camshaft to oscillate an output roller in response to rotary motion of the cam. The output roller drives an output cam which cooperates with a cam follower to open an engine intake valve conventionally against a valve spring. A curved return spring disposed between the output cam and the frame returns the output cam as the valve closes.

Abstract: A variable valve actuating comprising a spring guide for use with a curved spring includes an elongate, curved guide member having a centerline. The centerline has a centerline curvature that is substantially equal to the radius of curvature of the curved spring. The guide member has a first side having a side curvature. The side curvature is substantially equal to a curvature of the curved inside surfaces of the coils of the curved spring. The guide member is configured for being disposed within the curved spring such that the coils thereof substantially surround a periphery of the guide member.