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 that is configured to be non-rotatably connected to both the inner and outer camshafts, and a second camshaft phaser that is configured to be non-rotatably connected to one of the inner or outer camshafts.

An adjustable camshaft for a valve train of an internal combustion engine may include an inner shaft that is rotatable in an outer shaft, a phase shifter by which the outer shaft and/or the inner shaft are/is adjustable in a phase position formed around an axis of rotation, and a bearing portion for bearing the camshaft, via which the phase shifter can be supplied with a pressurizing medium. The inner shaft may comprise an end on which a screw flange is arranged, and a rotor of the phase shifter may be connected to the screw flange. A free end of the inner shaft comprises a duct that coincides with the axis of rotation for at least partially supplying the phase shifter with a pressurizing medium. The duct may extend at least into the bearing portion.

The disclosure relates to a variable valve drive, in particular with a sliding cam system, for an internal combustion engine. The variable valve drive has a cam carrier which has a first and second cam and a first, second, and third engagement track. A first actuator is designed to engage into the first engagement track in order to displace the cam carrier in a first axial direction. A second actuator is designed to engage into the second engagement track in order to displace the cam carrier in a second axial direction which is opposite to the first axial direction, and to engage into the third engagement track in order to displace the cam carrier in the first axial direction. The variable valve drive can have the advantage that, even in the event of a failure of the first actuator, a displacement of the cam carrier that is normally effected by means of the first actuator is possible by means of the second actuator.

A method concerns producing a cam profile of a cam pack with at least two cam elements that can be adjusted relative to each other. The camshaft may comprise an outer shaft, a rotatable inner shaft, a fixed cam element connected to the outer shaft, and an adjustment cam element connected to the inner shaft. The method may comprise processing an adjustment cam contour by a continuous diameter reduction of a segment of the adjustment cam base circle, wherein the adjustment cam base circle is reduced to a diameter that is smaller than a fixed cam nominal circle diameter minus a doubled adjustment cam base circle tolerance. The method may comprise processing a fixed cam contour by reducing a fixed cam contour protrusion in a region between a transition point and a processing point. Upon reaching the transition point a tapping element for converting a revolving motion of the cam elements into a linear motion of the valves is transferred from the fixed cam element to the adjustment cam element.

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, and a coupling that torsionally connects the first camshaft phaser to the second camshaft phaser. Each of the camshaft phasers is configured to be connected to either the inner or the outer camshaft. The coupling includes at least one flexible connector that provides for radial and axial movement between the first camshaft phaser and the second camshaft phaser.

An internal combustion engine system includes an engine with a plurality of pistons housed in respective ones of a plurality of cylinders, an air intake system to provide air to the plurality of cylinders through respective ones of a plurality of intake valves, an exhaust system to release exhaust gas from the plurality of cylinders through respective one of a plurality of exhaust valves, an aftertreatment system to treat exhaust emission from the engine, and a controller coupled to at least one sensor and configured to control a variable valve actuation mechanism to provide variable engine braking for thermal management.

A camshaft phaser arrangement configured for a concentric camshaft having inner and outer camshafts is provided. The camshaft phaser arrangement includes a first camshaft phaser and a second camshaft phaser. Each of the camshaft phasers is configured to be connected to either the inner or the outer camshaft. One or more couplers are arranged to torsionally couple the first camshaft phaser to the second camshaft phaser. A first end of the coupler is received by a radial slot configured within either the first or second phaser.

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 coupling includes a coupling ring and at least one coupling pin that torsionally connects the first camshaft phaser to the second camshaft phaser. The coupling provides for radial and axial movement between the first camshaft phaser and the second camshaft phaser.

An engine variable camshaft timing phaser (10) includes a sprocket (12) and a planetary gear assembly (14). The sprocket (12) receives rotational drive input from an engine crankshaft. The planetary gear assembly (14) includes two or more ring gears (26, 28), multiple planet gears (24), a sun gear (22), and a wrap spring (76). One of the ring gears (26, 28) receives rotational drive input from the sprocket (12) and one of the ring gears (26, 28) transmits rotational drive output to an engine camshaft. The sun gear (22) engages with the planet gears (24). The wrap spring (76) experiences expansion and contraction exertions to permit advancing and retarding engine valve opening and closing, and to prevent advancing and retarding engine valve opening and closing.

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.