The present disclosure relates to a sliding cam system for an internal combustion engine. The sliding cam system has a camshaft and a plurality of cam carriers with in each case at least two cams, the plurality of cam carriers being arranged fixedly on the camshaft so as to rotate with it and in an axially displaceable manner. The sliding cam system has a plurality of fluid-actuated actuator apparatuses which are configured in each case for axially displacing a cam carrier of the plurality of cam carriers. The sliding cam system has a fluid feed apparatus which is provided for feeding a fluid in a fluidic connection upstream of the plurality of actuator apparatuses for actuating the plurality of actuator apparatuses. At least two actuator apparatuses of the plurality of actuator apparatuses are coupled fluidically for simultaneous actuation.

A device for actuating at least one valve in an internal combustion engine includes a camshaft arrangement including a hollow outer shaft and an inner shaft, which is concentrically mounted inside of the outer shaft to be pivotable relative to the outer shaft. A first cam lobe is mounted on one of the inner shaft and the outer shaft in a rotationally fixed manner and a second cam lobe is mounted on the other of the inner shaft and the outer shaft in a rotationally fixed manner. The device further includes a rocker arm arrangement including a first primary rocker arm, which is arranged to follow the first cam lobe and arranged to actuate a first valve when it follows the first cam lobe. The rocker arm arrangement further includes an auxiliary rocker arm, which is arranged to follow the second cam lobe. The auxiliary rocker arm is adapted to actuate the first primary rocker arm so that an opening tune of the first valve may be extended by the auxiliary rocker arm following the second cam lobe.

A valve train assembly includes a rocker arm, comprising: a first roller, configured to engage a first rotatable cam surface; and a further roller, configured to engage a further rotatable cam surface, wherein at least part of the rocker arm can be pivoted by at least the first rotatable cam surface to move a valve to cause a first valve event, and wherein at least part of the rocker arm can be pivoted by the further rotatable cam surface to move the valve to cause a second valve event.

A variable valve duration apparatus may include a first cam rotating with a camshaft; a second cam rotating with the camshaft; a first operation device that is operated by the first cam to generate a valve lift; a second operation device that is operated by the second cam to generate the valve lift; and a controller controlling the first operation device or the second operation device to generate the valve lift according to an operation state of an engine.

A valve assembly selectively varies the timing of the valves in an internal combustion engine cycle by way of a first and second camshaft. Each valve has a shuttle portion and a valve portion. Upper and lower cam followers on the shuttle portion engage with first and second cams on each of the first and second camshafts to move the valve between an open and closed position with reference to a valve seat on an engine block.

An engine variable valve train includes a cam changeover mechanism for axially shifting a cylindrical cam carrier fitted on and around a camshaft for changing over cam lobes on the cam carrier to cause one of the cam lobes to selectively act on an engine valve for engine operation. The cam changeover mechanism includes changeover pins adapted to be advanced and retracted for engagement with or disengagement from a lead groove formed around the cam carrier, and with a changeover driving shaft constituting a linear motion cam mechanism for causing the changeover pins to selectively advance to engage with the lead groove. The cam carrier, while rotating with the cam shaft, is axially shifted by the action of the lead groove having the changeover pins selectively engaged therewith, so that the cam lobes are changed over and one of the cam lobe is made to act on the engine valve.

The present invention provides a camshaft capable of suppressing an increase in the number of parts and the number of places to be processed, preventing scratching on a sliding surface that is a part of an outer peripheral surface of an outer shaft and on which an inner cam is rotated, and preventing occurrence of deformation in the entire camshaft after final assembly. A camshaft includes an inner cam that is attached from a radial direction of an outer shaft and that is fixed to an inner shaft with a pin inserted into the inner cam from the radial direction of the outer shaft in a cam surface of the inner cam.

Internal combustion engines having a split crankshaft are disclosed. The engines may also have non-circular, preferably rectangular, cross-section pistons and cylinders. The pistons may include a skirt with a field of pockets that provide a ringless, non-lubricated, seal equivalent. The pistons also may have a domed piston head with depressions thereon to facilitate the movement of air/charge in the cylinder. The engines also may use multi-stage poppet valves in lieu of conventional poppet valves. The engines may use the pumping motion of the engine piston to supercharge the cylinder with air/charge. The engines also may operate in an inverted orientation in which the piston is closer to the local gravitationally dominant terrestrial body's center of gravity at top dead center position than at bottom dead center position.

Internal combustion engines that use the pumping motion of the engine pistons to supercharge the cylinder with air/charge are disclosed. The pistons may include a skirt with a field of pockets that provide a ringless, non-lubricated, seal equivalent. The piston heads may be domed with one or more depressions to facilitate the movement of air/charge in the cylinder. The engines also may have non-circular, preferably rectangular, cross-section pistons and cylinders. The engines also may use multi-stage poppet valves in lieu of conventional poppet valves, and may include a split crankshaft. The engines also may operate in an inverted orientation in which the piston is closer to the local gravitationally dominant terrestrial body's center of gravity at top dead center position than at bottom dead center position.

A variable valve actuation mechanism is provided for an internal combustion engine including at least one valve for control of gas admission to a cylinder of the engine and/or gas exhaust from the cylinder. The mechanism includes two concentrically arranged camshafts, a cam set comprising two cams, each fixed to a respective of the camshafts, whereby the camshafts are arranged to be turned in relation to each other, so as to change the combined profile of the cams, and a cam follower adapted to follow the combined profile of the cams and to actuate at least one of the at least one valve in dependence on the combined profile of the cams, wherein the cam follower includes two rollers, each roller being adapted to follow a respective one of the cams.