Abstract: A variable phase drive coupling is described for providing drive from an engine crankshaft to two sets of cams. The drive coupling comprising a drive member 12 connectable for rotation with the engine crankshaft and two driven members 18, 20 each connectable with a respective one of the two sets of cams. In the invention, the angular relationship of each of the driven members 18, 20 is independently variable relative to the drive member 12 under the action of camshaft torque reversals.

Abstract: In the case of a valve, in particular a gas exchange valve of an internal combustion engine, valve lifting movements with valve displacement curves should be possible with a control unit in a mechanically simple manner, these curves being composed of a main valve displacement curve, the execution of which may be designed to be variable and at least one variable additional valve displacement curve. The phase relation between the main valve displacement curve and the additional valve displacement curve may also be variable.

Abstract: An engine is described having a camshaft 10 formed of an inner shaft 12 and an outer tube 14 both of which rotate with respective groups of cams 18 and 16. A drive train driving both the inner shaft 12 and the outer tube from the engine crankshaft includes a phaser 30 for enabling the phase of at least one of the groups of cams 16 and 18 to be varied dynamically relative to the phase of the crankshaft. The phaser is secured to the front end of the outer tube 14 and the inner shaft 12 of the camshaft 10 is connected to the front side 36 of the phaser 30 by way of a driving member 46 that encloses the component 40 securing the phaser to the outer tube 14 of the camshaft 10.

Abstract: A camshaft assembly 10 is disclosed which comprises an inner shaft 12, an outer tube 14 surrounding and rotatable relative to the inner shaft 12, and two groups of cam lobes 16 and 18 mounted on the outer tube 14. The first group of cam lobes 16 is fast in rotation with the outer tube 14 and the second group 18 is rotatably mounted on the outer tube 14 land connected for rotation with the inner shaft 12 by means of pins 20 that pass with clearance through slots in the outer tube 14. A spring 138 is incorporated in the camshaft assembly 10 to bias the inner shaft 12 relative to the outer tube 14 towards one extreme of its angular range.

Abstract: A valve operating mechanism is described for an internal combustion engine in which at least one valve (14) of an engine cylinder is operated by two cams (10,12). The cams (10,12) have respective cam followers (38,36) which are resiliently biased to remain in contact with the cams (10,12) at all times and which act on the valve (14) by way of a summation linkage (20,24) in such a manner that the displacement of the valve (14) at any instant is determined by a combination of the displacements of the two cam followers (38,36). In the invention, movement of each of the two cam followers (38,36) is transmitted to the summation linkage (20,24) by way of a respective one of two pushrods (28,30).

Abstract: An engine is described having two camshafts 14, 16 each of which carries two groups of cams and comprises an inner shaft coupled for rotation with a first group of cams and an outer tube rotatably supported by the inner shaft and coupled for rotation with the second group of cams. A phaser 12 is provided to enable the phase of at least one of the two groups of cams on one of the SCP camshafts 14, 16 to be varied with reference to the phase of the engine crankshaft. Drive links in the form of meshing gearwheels, drive chains or belts, couple the two corresponding groups of cams on the respective camshafts for rotation in unison with one another.

Abstract: A twin vane-type phaser is described which is provided with a locking mechanism for locking the drive member to the driven members when the pressure in the working chambers is a below is predetermined value. The locking mechanism comprises two coaxial locking pins 114, 118 mounted in a common bore 110 in the centrally located member 32. The locking pins are resiliently urged apart by a spring 120 into bores in the two outer members 38, 40 and are retracted by pistons 112, 116 when the hydraulic pressure in the working chambers attains the predetermined value.

Abstract: A hydraulic phase shifting mechanism is described for an engine camshaft subjected to torque fluctuations during operation. The mechanism employs a magnetorheological fluid as a hydraulic pressure medium and is controlled by selective application of a magnetic field to vary the flow properties of the magnetorheological fluid.