A valvetrain for an internal combustion engine has a camshaft rotatable about an axis of rotation, a sliding-block element connected in a rotationally fixed manner to the camshaft and displaceable in the axial direction of the camshaft relative thereto, which sliding-block element has an outer circumferential jacket surface with a shift gate via which a rotational movement of the sliding-block element can be converted into a displacement of the sliding-block element in the axial direction of the camshaft relative thereto, and a shift rod at least partially accommodated in the camshaft and displaceable by the sliding-block element in the axial direction of the camshaft relative thereto and via which shift rod an actuation of a gas exchange valve can be influenced.

A valve train device, in particular for an internal combustion engine, includes a support element secured to a housing, at least one axially moveable cam unit associated with a valve, and at least one switch unit for axially moving at least one part of the cam unit having at least one displacement body which is provided to be introduced for axial movement at least functionally between the support element and the cam unit. The cam unit has at least three cam paths.

A camshaft for an engine and a method of assembling such a camshaft, wherein the camshaft has a base shaft and an external toothing which extends at least in certain portions axially along the base shaft A hub has an internal toothing which correlates with the external toothing of the base shaft such that the hub is connected rotationally conjointly and axially non-displaceably to the base shaft. The external toothing has at least one form-fit subregion, which extends axially at least in certain portions along the base shaft, or one force-fit subregion in order for the hub to be arranged at least in a form-fitting or force-fitting manner, and wherein at least the form-fit subregion or the force-fit subregion is adjoined by at least one alignment region which extends at least in certain portions axially along the base shaft and which serves for the angular alignment of the hub.

Systems, apparatuses and methods are disclosed that include an internal combustion engine including a plurality of cylinders operable by a valve actuation mechanism including a lifting mechanism having a compression brake valve profile configured to selectively lift the exhaust valves on a downstroke of the cylinders in response to a cranking condition of the internal combustion engine, wherein the compression braking valve profile is phased to the upstroke of the pistons.

A variable camshaft timing system including a first camshaft phaser having an input that is configured to receive rotational force from a crankshaft and an output that is configured to link with a first camshaft of a concentric camshaft assembly to change the angular position of the first camshaft relative to a crankshaft; and a second camshaft phaser having an output that is configured to link with a second camshaft of the concentric camshaft assembly to change the angular position of the second camshaft relative to the crankshaft, wherein the first camshaft is concentrically positioned to the first camshaft and the first camshaft phaser is mechanically linked to the second camshaft phaser to communicate rotational force from the crankshaft to the second camshaft phaser through the first camshaft phaser and the mechanical link.

A summation rocker system is disclosed for acting on the end of a stem of a poppet valve (16) in dependence upon the combined lifts of a first and a second cam profile defined by different cam lobes (14, 22) of a concentric camshaft (46). The system comprises a first rocker (12) mounted on a pivot shaft (18) and having a first follower (44) to contact the first cam profile and an end acting on the valve (16) to displace the valve (16) by an amount dependent upon the lift of the first cam profile, a rocker shaft (24) to be fixedly mounted on the engine, and a second rocker (20) pivotable about the rocker shaft (24), the second rocker (20) having a second follower (48) to contact the second cam profile and acting to displace the pivot shaft (18) of the first rocker (12) in dependence of the lift of second cam profile. The rocker shaft (24) intersects a plane containing the axis of the pivot shaft (18) and the end of the first rocker (12) acting on the valve stem, and the first rocker (12) includes a cut-out (26) for receiving the rocker shaft (24), which cut-out (26) is configured and dimensioned to prevent the rocker shaft (24) from interfering with movement of the first rocker (12).

A valve train may include a camshaft, a cam sleeve adjustable in an axial direction between first and second positions and non-rotatably arranged on the camshaft, a first cam and at least one second cam, a pin and at least one cam follower mounted thereon, a guide contour arranged on the cam sleeve and having first and second guide tracks, and a control pin optionally engaging in the first or second guide track to adjust the cam sleeve between the first and second positions. The at least one cam follower in the first and second positions may interact respectively with the first and second cams. On the camshaft or an internal surface of the cam sleeve, first and second snap-in recesses and a third snap-in recess therebetween may be arranged. A snap-in device having a snap-in element preloaded into the snap-in recesses may be provided, the snap-in recess fixing the cam sleeve in the first or second position. The first and second guide tracks may intersect in an intersection region. Between the first and third snap-in recesses and between the second and third snap-in recesses, first and second snap-in humps may respectively be arranged. The snap-in element may engage in the third snap-in recess when the control pin is in the intersection region.

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 camshaft for an engine and a method of assembling such a camshaft, wherein the camshaft has a base shaft and an external toothing which extends at least in certain portions axially along the base shaft A hub has an internal toothing which correlates with the external toothing of the base shaft such that the hub is connected rotationally conjointly and axially non-displaceably to the base shaft. The external toothing has at least one form-fit subregion, which extends axially at least in certain portions along the base shaft, or one force-fit subregion in order for the hub to be arranged at least in a form-fitting or force-fitting manner, and wherein at least the form-fit subregion or the force-fit subregion is adjoined by at least one alignment region which extends at least in certain portions axially along the base shaft and which serves for the angular alignment of the hub.

A method of joining a functional module comprises the steps of providing a frame structure that defines a bearing channel with at least one circumferentially closed bearing seat; providing at least two attachment parts; providing a hollow shaft that comprises at least one support section for the at least two attachment parts, wherein the attachment parts comprise a mounting seat that is adapted to a support section; feeding the attachment parts in the bearing channel in a first feeding direction; feeding the hollow shaft in the bearing channel in a second feeding direction, wherein the hollow shaft is inserted into the respective mounting seat of the at least two attachment parts; and, subsequent to the feeding of the attachment parts and the hollow shaft in the bearing channel, at least sectionally widening the hollow shaft for a torsionally rigid fixation of the at least two attachment parts with their mounting seats at the respective support section of the hollow shaft.