A continuously variable valve duration (CVVD) system includes an electronic control unit (ECU) configured to output a command for adjusting an actuator and a controller configured to determine a operation range of a control shaft of the actuator and adjust the control shaft in the determined operation range based on the command of the ECU. The controller positions the control shaft at a predetermined target phase and determines a control state of each target phase based on a target phase value transmitted from the actuator when the control shaft is positioned at the target phase.

A rocker arm assembly can comprise a main rocker arm and a latch assembly. A latching arm can control the latch assembly and thereby control the extent to which a secondary rocker arm acts on the main rocker arm. The main rocker arm can comprise a main body configured to rotate around a rocker shaft, a valve end extending from the main body, a reaction end extending from the main body, and a latch bore. A bias pin can extend from the main body. The latch assembly can be configured to selectively rotate in the latch bore. The latch assembly can comprise a first latch end comprising a switch plate configured to receive actuation force on a first side and to receive bias force from the bias pin on a second side. A second latch end can comprise a first latch seat and a second latch seat.

An engine valve actuation system includes engine braking rocker arms each having a hydraulically actuated switch, and an electrohydraulic control system including an actuation fluid supply, an electrically actuated valve adjustable to vary a pressure of actuation fluid supplied from the actuation fluid supply to the hydraulically actuated switches, and an engine braking control unit. The engine braking control unit is structured to command adjusting the electrically actuated valve to adjust the hydraulically actuated switch in each of the engine braking rocker arms at a switching window timing that is varied from engine braking cycle to engine braking cycle to distribute hard handoffs among the engine braking rocker arms.

A shift gate for a sliding cam system may include at least two shift grooves for engagement of at least one actuator pin. The two shift grooves run against a direction of rotation and transform from a first inlet portion for the actuator pin into a second outlet portion for the actuator pin. The two shift grooves cross one another in an intersection region between the two portions. In the intersection region, the two shift grooves each have a maximum axial shift stroke that is greater than half a total axial shift stroke, in particular a slide travel, of the shift gate.

A valve train may include a camshaft, a cam follower, and first and second cams mounted axially adjacent in a torque-proof manner on the camshaft. The valve train may also include an adjustment arrangement having adjustable first and second mechanical engagement elements, which may each cooperate with at least one slide guide arranged on the camshaft. The valve train may further include a control shaft or control slide forming a stop for the first and second engagement elements and adjusting the first and second engagement elements into respective switching positions. The cam follower may be drivingly connected with the first and second cams in first and second positions, respectively. The first and second engagement elements may each be adjustable between respective basic positions, in which no contact exists with the associated slide guide, and the respective switching positions, in which the respective engagement element cooperates with the associated slide guide.

An engine includes a block containing multiple valves, and a camshaft defining multiple cams for rotation about a camshaft axis. A valve lift assembly is operatively associated with a respective one of the cams and a respective one of the valves to transfer motion from the cam to the valve by reciprocal motion of the valve lift assembly along a lift axis. The assembly includes a follower and a follower control mechanism. The follower is disposed in contact with the cam at a contact point that defines a contact path extending along a surface of the cam as the cam rotates about the camshaft axis. The follower is moveable through an adjustment range to change the position of the contact point along the contact path at a given angular position of the cam. The follower control mechanism is operable to control the movement of the follower within the adjustment range.

An engine that can implement cylinder deactivation (CDA) includes: a plurality of cylinders; a variable valve duration apparatus that is mounted in at least one of the plurality of cylinders and that performs a long duration mode and a short duration mode of an intake valve of a corresponding cylinder; a CDA apparatus that is mounted in at least another one of the plurality of cylinders and that performs a general operation mode and a CDA mode of an intake valve and an exhaust valve of a corresponding cylinder; and a controller that controls operation of the variable valve duration apparatus and the CDA apparatus according to an operation state of an engine, wherein the controller controls the variable valve duration apparatus to operate in a short duration mode, when the CDA apparatus operates in the CDA mode.

A cam system for operating a first engine valve and a second engine valve includes translatable first and a second sliding lobe packs. The first sliding lobe pack operates the first engine valve with one of a high lift lobe, a low lift lobe, and a zero lift lobe. The second sliding lobe operates the second engine valve with one of a high lift lobe or one of two low lift lobes. A shift barrel has a first groove configured to translate the first and a second sliding lobe packs in a first direction, and a second groove configured to translate the first and a second sliding lobe packs in a second direction, opposite the first. A shift actuator has a first pin, a second pin, and a third pin, each selectively actuatable to engage the first groove or the second groove.

An automobile vehicle overhead camshaft system includes multiple camshafts individually having multiple sliding camshaft barrels. Opposed ends of the camshaft barrels individually have a zero-lift lobe. Multiple intake valves are operated by a first one of the camshafts and multiple exhaust valves are operated by a second one of the camshafts. Multiple actuators operate during a deceleration cylinder cut-off (DCCO) mode to slidably displace the camshaft barrels to position the zero-lift lobe of predetermined ones of the multiple sliding camshaft barrels into contact with at least one of: all of the intake valves; or all of the exhaust valves.

This invention describes a variable valve timing mechanism which may be fitted to an internal combustion engine to provide precise control over timing of the valve opening and closing events of the camshaft relative to the crankshaft. Various methods for its application are described to provide settable valve timing at either predetermined angle selected by the operator, or automatic variable valve timing as governed by parameters of the operating engine. Said mechanism comprised of oppositely located idler rollers, whereas not bound to a single yoke or carrier, are driven by a cam to achieve independent movement of the rollers, which bear against both tension and slack sides of the belt between the crankshaft and camshaft pulleys causing predictable and repeatable variation in valve timing. Thus, this invention, whereby coordinated but non-uniform movements of the idler rollers is achieved by the mechanical appurtenances described herein, including a specially developed cardioid cam to actuate said idler rollers, produces precise changes in camshaft phase angle.