A continuous variable valve duration apparatus may include a camshaft, a cam unit on which a cam is formed, wherein the camshaft is inserted into the cam unit, a guide bracket having an upper guide boss formed thereon, an internal wheel transmitting rotation of the camshaft to the cam unit, a wheel housing in which the internal wheel is rotatable inserted, wherein the wheel housing includes a guide shaft on which a guide screw thread is formed and the guide shaft is inserted into the upper guide boss to be movable, a worm wheel to which an internal screw thread engaging with the guide screw thread is formed therewithin, and to which an external screw thread is formed thereon, and a control shaft on which a control worm engaging with the external screw thread is formed.

A camshaft phaser assembly, including: an axis of rotation; a first hydraulic camshaft phaser including a first stator arranged to receive rotational torque, a first rotor including a plurality of first through-bores, and a first plurality of phaser chambers circumferentially bounded by the first stator and the first rotor; a second hydraulic camshaft phaser including a second stator non-rotatably connected to the first stator, a second rotor, and a second plurality of phaser chambers circumferentially bounded by the second stator and the second rotor; a first trigger wheel including a plurality of second through-bores connected to the plurality of first through-bores, non-rotatably connected to the first rotor, and arranged to identify a rotational position of the first rotor; and a second trigger wheel non-rotatably connected to the second rotor and arranged to identify a rotational position of the second rotor.

A camshaft phaser arrangement configured for a concentric camshaft assembly having inner and outer camshafts is provided. The camshaft phaser arrangement includes a first camshaft phaser, a second camshaft phaser, a coupling, and at least one timing wheel connected to at least one of the first or second camshaft phaser. Each of the camshaft phasers is configured to be connected to either the inner or the outer camshaft. The at least one timing wheel defines at least one cutout that is configured to receive at least a portion of the coupling.

A camshaft adjusting system (1) is provided for a first camshaft (2) and a second camshaft (3) which are arranged concentrically with respect to one another, the second camshaft (3) being arranged within the first camshaft (2). A vane-cell type hydraulic camshaft adjuster (4) is configured for adjusting the first camshaft (2) and an electric camshaft adjuster (5) is configured for adjusting the second camshaft (3). A front cover (7) which is fastened to a stator (6) of the hydraulic camshaft adjuster (4) and which closes off the camshaft adjuster (4) at a side facing away from the camshaft has an internal toothing (8) for supporting a flex pot (9) which is attached to the second camshaft (3) and which is designed for receiving torque from the electric camshaft adjuster (5). A camshaft adjusting unit having the camshaft adjusting system (1) and two camshafts (2, 3) is also provided.

An engine camshaft has a lubricating oil passage formed along the longitudinal axis of the same, a cam communicating oil hole is radially formed from the lubricating oil passage to an outer peripheral surface of the camshaft at the same axial position as an engine valve. Cam lubrication holes are radially formed from the inside to cam surfaces of cam lobes formed around a cam carrier fitted around the camshaft. One of the cam lubrication holes of the cam lobes shifted to a position for operating the valve communicates with the cam communicating oil hole of the camshaft to supply lubricant oil.

An engine variable valve train is provided with a cylindrical cam carrier fitted on a camshaft in a manner axially slidable to and co-rotatable with the camshaft. The cam carrier has therearound mutually adjoining low-speed and high-speed cam lobes selectively acting on the engine valve and being different in cam profile. The cam carrier has therearound lead grooves to be engaged with or disengaged from changeover pins for axial shift of the cam carrier. The lead grooves include a speed-increasing lead groove for changeover from the low-speed to the high-speed cam lobe and a speed-decreasing lead grooves for changeover from the high-speed to the low-speed cam lobe. The speed-increasing and speed-decreasing lead grooves are different in groove contour. This enables the cam carrier to axially shift smoothly and to improve the durability of the lead grooves.

This disclosure relates to a camshaft adjusting system for a motor vehicle, having an inner camshaft, and an outer camshaft, which is arranged coaxially with and radially outside the inner camshaft. The camshaft adjusting system further includes an input wheel, which is designed to introduce torque into the camshafts, a hydraulic camshaft adjuster, which acts on the outer camshaft to adjust the phase angle of the outer camshaft relative to the input wheel, and an electric camshaft adjuster, which acts on the inner camshaft to adjust the phase angle of the inner camshaft relative to the input wheel. The electric camshaft adjuster engages in the hydraulic camshaft adjuster at least partially in an axial direction.

A valvetrain for an internal combustion engine has a camshaft that can be rotated in a direction of rotation around an axis of rotation, at least two cam pieces arranged on the camshaft which each have at least two cams for actuating a respective gas exchange valve and which are rotationally fixedly connected to the camshaft, and an actuator via which the cam pieces can be shifted in the axial direction of the camshaft. A first of the cam pieces has a first rib protruding outwardly from a first base body of the first cam piece in the radial direction of the camshaft and the second cam piece has a second rib protruding outwardly from a second base body of the second cam piece in the radial direction of the camshaft.

Disclosed is a method and system for intermittently operating poppet valves in an internal combustion engine when desired by the selective locking or unlocking of one or more cam lobes with the camshaft. One or more cam lobes, with a small radial clearance, ride on a camshaft such that an engagement mechanism may be activated as desired to lock the cam lobe to the camshaft, thereby activating the respective poppet valve. The cam lobe is prevented from moving axially to ensure correct alignment with a follower. A suitable holding device may be used to ensure the non-activated cam lobes are restrained at a suitable orientation relative to the cam follower.

A dual cam phaser for an internal combustion engine, the dual cam phaser including a stator which is drivable by a crankshaft; a rotor which rotatable relative to the stator; a first camshaft; a second camshaft; and a mechanical switching element which is connected to the first camshaft and the second camshaft, wherein the first camshaft and the second camshaft are arranged coaxial with one another, wherein the first camshaft or the second camshaft is connected with the rotor to rotate together with the rotor, and wherein a phase difference between the first camshaft and the second is adjustable by the mechanical switching element.