Abstract: A vane-type phaser connected to drive an assembled camshaft includes a drive member and a driven member each connected to a respective one of the inner and outer shafts of the camshaft. A first of the members includes a disc with at least one arcuate cavity that is open at both axial ends. The second member includes two closure plates sealing off the axial ends of each cavity of the first member and at least one vane formed separately from the closure plates which is movably received in a respective cavity to divide the cavity into two variable volume working chambers. Each vane is secured at both its axial ends to the two closure plates.

Abstract: A camshaft assembly is disclosed which comprises an inner shaft, an outer tube surrounding and rotatable relative to the inner shaft, and two groups of cam lobes mounted on the outer tube, the first group of cam lobes being fast in rotation with the outer tube, the second group being rotatably mounted on the outer surface of the tube and connected for rotation with the inner shaft. The connection between the second group of cam lobes and the inner shaft is effected by means of driving members whose positions are adjustable in order to compensate for significant manufacturing inaccuracies between the inner shaft and its associated group of cam lobes.

Abstract: A mechanism for actuating a poppet valve (28) of an internal combustion engine, comprises two coaxially mounted cams (12,14), cam followers (18,20) in contact with the respective cams (12,14) mounted on a common summation lever (16) which is movable in proportion to the instantaneous sum of the lifts of the two cams (12,14), and a rocker (24) pivotably connected to the summation lever (16) and serving to open the engine valve (28). The rocker is pivotable about a pivot (126) having a fixed preset position and a control spring (134) is provided between the summation lever (16) and a fixed point on the engine to urge the rocker (24) into contact with the tip of the valve (28) and the pivot (126) while the valve is closed.

Abstract: An assembly is provided comprising an SCP camshaft (130) having an inner shaft (140) and an outer tube (124) and a hydraulically operated twin vane phaser (110) having two output members (114, 116) coupled respectively for rotation with the inner shaft (140) and the outer tube (124) of the SCP camshaft (130). Each of the output members (114, 116) of the twin phaser is axially clamped to a respective one of the inner shaft (140) and the outer tube (124)of the SCP camshaft (130). A support bearing (150) for the twin vane phaser (110), having passageways (142) for supplying pressure medium to working chambers of the twin vane phaser (110), is formed separately from the SCP camshaft (130).

Abstract: Hydraulically operated camshaft phasers are described which comprise a drive member and a driven member having a fixed range of angular adjustment and a means for mechanically locking the position of the driven member relative to the drive member when there is insufficient hydraulic pressure to operate the phaser. In the invention, the lock operates in an intermediate position within the range of adjustment, and a hydraulic circuit is provided for biasing the phaser towards the intermediate position for the lock to engage.

Abstract: A variable phase mechanism is described which comprises a drive member rotatable about an axis, first and second driven members rotatable in synchronism with the drive member, an actuator for rotating the first driven member relative to the drive member to vary the phase of rotation of the first driven member relative to the drive member, and a yoke coupling the second driven member for rotation with one of the drive member and the first driven member and movable transversely relative to the axis of the drive member to vary the phase of rotation of the second driven member relative to the drive member. In the invention, transverse movement of the yoke is effected by means of interaction between the other of the drive member and the first driven member and a radially outwards facing surface defined by the yoke.

Abstract: A vane-type phaser connected to drive an assembled camshaft includes a drive member and a driven member each connected to a respective one of the inner and outer shafts of the camshaft. A first of the members includes a disc with at least one arcuate cavity that is open at both axial ends. The second member includes two closure plates sealing off the axial ends of each cavity of the first member and at least one vane formed separately from the closure plates which is movably received in a respective cavity to divide the cavity into two variable volume working chambers. Each vane is secured at both its axial ends to the two closure plates.

Abstract: An actuating system for a gas exchange valve of an internal combustion engine is described which comprises two cams (12,14) associated with the valve (10), a summation linkage (22,24,30,32) for lifting the valve in dependence upon the sum of the instantaneous lifts of the two cams (12,14). A de-activating mechanism 34 is provided for selectively decoupling the summation linkage from one (12) of the two cams.

Abstract: An internal combustion engine is described having a valve mechanism that comprises an SCP camshaft operating two sets of valves. The first set of valves is operated via a summation rocker system such that the valve lift characteristic results from the combination of two cam profiles. The second set of valves has a valve lift characteristic that is different from that of the first set. In the invention, changing the valve lift characteristic of the first set of valves by varying the phase of the inner shaft of the SCP camshaft relative to the outer tube of the SCP camshaft serves additionally to alter the operation of the second set of valves.

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: The invention relates to a camshaft assembly comprising an inner shaft, an outer tube rotatable relative to the inner shaft, and two groups of cams mounted on the outer tube, the first group of cams being fast in rotation with the outer tube, and the second group being rotatably mounted on the outer surface of the tube and being connected for rotation with the inner shaft by means of connecting members that pass through circumferentially elongated slots in the outer tube. In the invention, the outer tube surrounds the inner shaft with clearance and the members connecting different ones of the cams of the second group to the inner shaft are inclined relative to one another and act to locate the axis of the inner shaft relative to the outer tube.

Abstract: A valve system is disclosed for an internal combustion engine which allows a secondary valve event, serving for example to provide internal EGR, to be selectively disabled. The system comprises two valve 10 and 22, a first cam 20 acting on the first valve 10 by way of a rocker 12 pivotable about a fixed pivot axis and a second cam 36 having at least two lobes and acting on the second valve 22 by way of a second rocker 24 pivotable about an eccentric 26. The second of the two lobes of the second cam 36 is arranged to open the second valve 22 at a time that the first valve 10 is opened by the first cam 20. A selectively operable latching mechanism 50 latches the eccentric 26 in a fixed position in which each of the cam lobes of the second cam causes the second valve to open.

Abstract: A rotary hydraulic coupling is described for use in an engine having a camshaft, a hydraulic phaser for driving the camshaft, and an oil feed manifold secured to the body of the engine and incorporating oil galleries for supplying oil to the phaser. The rotary coupling, which serves to connect the oil galleries of the oil feed manifold to rotating oil ducts which lead to hydraulic working chambers within the phaser, comprises a cylindrical first element rotatably received within and sealed relative to an annular second element, each of the first and second elements having bores that communicate with annular grooves in a mating surface of at least one of the two elements to establish fluid flow communication between the bores in the two elements, the bores in the first element being connected to axially extending oil passages formed within the first element.

Abstract: A valve train comprises a poppet valve 18 actuated by two rotatable cams 30, 32 which can preferably be phase shifted relative to one another. A first rocker 39 is supported on a fixed rocker 40 shaft by way of an eccentric sleeve 42 that is rotatable relative to the rocker shaft 40. A second rocker 37 directly supported on the rocker shaft 40 acts to rotate the eccentric sleeve 42 about the rocker shaft 40. In this way, the first rocker 39, which is operated by a first cam 30 and acts on the poppet valve 18 has its axis of rotation displaced cyclically towards and away from the valve 18 by the action of the second cam 32 and the second rocker 37.

Abstract: A gas exchange valve of an internal combustion engine, has valve lifting movements with valve displacement curves and a control unit. To this end, a control unit is provided for operation of at least one valve, in particular a gas exchange valve of an internal combustion engine, in which the valvelifting movement of the at least one valve (6) is generated by superimposing two synchronously rotating cam profiles acting mechanically on a lift operating element (4). The two cam profiles (1, 2) have specially shaped areas by means of which, when superimposed to form one of the two cam profiles (1, 2), at least one additional valve displacement (ZV) can be generated on the whole in addition to a main valve displacement movement (HV) over a full revolution of each of these cam profiles (1, 2).

Abstract: A mechanism for actuating an engine poppet valve includes two rotatable cams, a first rocker mounted on a pivot shaft and acting between a first of the two cams and the stem of the valve, and a second rocker mounted for rotation about a fixed axis and acting between the second of the two cams and the pivot shaft of the first rocker to raise and lower the pivot axis of the first rocker cyclically in synchronism with the rotation of the second cam, whereby the valve is operated in dependence upon the instantaneous sum of the lifts of the two cams.

Abstract: A camshaft assembly comprises an inner shaft 12 and an outer tube 14 surrounding and rotatable relative to the inner shaft. Two groups of cam lobes are mounted on the outer tube 14 , the first group of cam lobes 16 being fast in rotation with the outer tube 14 and the second group of lobes 26 being rotatably mounted on the outer surface of the tube 14 and connected for rotation with the inner shaft by means of pins 22 that pass with clearance through slots in the outer tube 14 . A sleeve 20 rotatably mounted on the outer tube 14 is connected to impart drive to the inner shaft 12 by means of a pin 24 passing with clearance through a circumferentially extending slot in the outer tube 14.

Abstract: Hydraulically operated camshaft phasers are described which comprise a drive member and a driven member having a fixed range of angular adjustment and a means for mechanically locking the position of the driven member relative to the drive member when there is insufficient hydraulic pressure to operate the phaser. In the invention, the lock operates in an intermediate position within the range of adjustment, and a hydraulic circuit is provided for biasing the phaser towards the intermediate position for the lock to engage.

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 SAP camshafts 14, 16 to be varied with reference to the phase of the engine crankshaft. Drive links in the form of meshing gear wheels, drive chains or belts, couple the two corresponding groups of cams on the respective camshafts for rotation in unison with one another.

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.