Abstract: 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.

Abstract: A hybrid dual phaser assembly is disclosed for mounting to an engine camshaft to allow the timing of two sets of cam lobes to be phased independently of one another relative to a crankshaft of the engine. The phaser assembly comprises an electrically operated phaser having intermeshing gears for transmitting torque to the camshaft and a phase control input driven by an electric motor to be mounted coaxially with the camshaft, and a hydraulically operated phaser having vanes movable within arcuate cavities. The cavities of the hydraulically operated phaser are defined in part by an annular member that radially surrounds, and axially overlaps, a gear of the electrically operated phaser, which gear is separate from the annular member and forms radially inner boundary walls of the cavities.

Abstract: A hybrid dual phaser assembly is disclosed for mounting to an engine camshaft to allow the timing of two sets of cam lobes to be phased independently of one another relative to a crankshaft of the engine. The phaser assembly comprises an electrically operated phaser having intermeshing gears for transmitting torque to the camshaft and a phase control input driven by an electric motor to be mounted coaxially with the camshaft, and a hydraulically operated phaser having vanes movable within arcuate cavities. The cavities of the hydraulically operated phaser are defined in part by an annular member that radially surrounds, and axially overlaps, a gear of the electrically operated phaser, which gear is separate from the annular member and forms radially inner boundary walls of the cavities.

Abstract: 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.

Abstract: A valve system for an engine includes two cams each having a follower, a summation lever coupled to the followers, a lash adjuster, a valve actuating rocker pivotably coupled to the summation lever and resting on the lash adjuster, a control spring urging the summation lever to compress the lash adjuster, a stop limiting an expansion of the control spring, a bore, a plunger which moves in the bore, and an abutment surface. The control spring acts on the summation lever via the plunger. A plunger end engages with the summation lever. A point of contact between the plunger and the summation lever is displaced in a direction transverse to a plunger axis during a pivoting movement of the summation lever. A plunger shoulder is arranged a distance from the plunger end to contact the abutment surface to limit a plunger displacement in a direction compressing the lash adjuster.

Abstract: A valve system for an engine includes two cams each having a follower, a summation lever coupled to the followers, a lash adjuster, a valve actuating rocker pivotably coupled to the summation lever and resting on the lash adjuster, a control spring urging the summation lever to compress the lash adjuster, a stop limiting an expansion of the control spring, a bore, a plunger which moves in the bore, and an abutment surface. The control spring acts on the summation lever via the plunger. A plunger end engages with the summation lever. A point of contact between the plunger and the summation lever is displaced in a direction transverse to a plunger axis during a pivoting movement of the summation lever. A plunger shoulder is arranged a distance from the plunger end to contact the abutment surface to limit a plunger displacement in a direction compressing the lash adjuster.

Abstract: A camshaft assembly is disclosed that 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 is fast in rotation with the outer tube and the second group is rotatably mounted on the outer surface of the outer tube and is connected for rotation with the inner shaft. A timing wheel is connected for rotation with the inner shaft to provide position information to a sensor, the timing wheel being formed as a separate part that is assembled to one of the cam lobes in the second group.

Abstract: A variable valve actuating mechanism comprising a camshaft having two concentric cam lobes that may be rotated relative to one another a summation lever engaging with both cam lobes, a valve actuating rocker pivotally connected to the summation lever and engaging with a hydraulic lash adjuster at a first end and with a valve at a second end, and a shim surface movable with the pivot axis connecting the summation lever to the valve actuating rocker for limiting the expansion of the hydraulic lash adjuster to control clearance in the rocker system, wherein, in order to reduce friction, the shim surface abuts with a stationary stop surface that forms part of a camshaft support bearing.

Abstract: A rocker system comprising a summation lever and at least one valve actuating lever for use in a valve train of the type having two cams, a summation lever having followers engaging with both cams and a valve actuating lever pivotally connected to the summation lever for opening and closing an engine valve in dependence upon the sum of the lifts of the two cams, characterised in that the summation lever is assembled from opposed face plates and a separately formed hub.

Abstract: A variable valve actuating mechanism comprising a camshaft having two concentric cam lobes that may be rotated relative to one another a summation lever engaging with both cam lobes, a valve actuating rocker pivotally connected to the summation lever and engaging with a hydraulic lash adjuster at a first end and with a valve at a second end, and a shim surface movable with the pivot axis connecting the summation lever to the valve actuating rocker for limiting the expansion of the hydraulic lash adjuster to control clearance in the rocker system, wherein, in order to reduce friction, the shim surface abuts with a stationary stop surface that forms part of a camshaft support bearing.

Abstract: An engine valve system comprises two cams (10,12) mounted coaxially, a summation rocker (14) coupled to followers (16,18) of both cams and movable in proportion to the instantaneous sum of the lifts of the respective cams, and a valve actuating rocker (20) pivotably coupled to the summation rocker (14) and operative to open an engine valve (22) in dependence upon the movement of the summation rocker (14). In the invention, the actuating rocker (20) rests on a hydraulic lash adjuster (24). A control spring (136) is provided to urge the summation rocker (14) in a direction to compress the hydraulic lash adjuster (24). A stop (138) associated with the control spring (136) limits the movement of the summation rocker (14) towards the lash adjuster (24) so as to set the clearance in the valve system when the valve (22) is closed and the cam followers (16,18) are on the base circles of the two cams (10,12).

Abstract: A camshaft assembly 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 mounted on the outer tube, the first group of cam lobes being fast in rotation with the outer tube, and each cam (10) lobe (18) of the second group being rotatably mounted on the outer surface of the tube (14) and connected for rotation with the inner shaft (12) by means of one or more drive members (50) passing through circumferentially elongated slots in the outer tube. In the invention, each drive member comprises a (15) drive component (50d) engaged with fixed alignment in the cam lobe (18) and a separate fastener (50b) that is rotatable to clamp the drive component against a flat surface on the inner shaft (12), each drive member (50) being constructed such that during the tightening of the fastener (50b) no relative (20) sliding movement is required at the interface between the drive component (50d) and the inner shaft (12).

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: 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: An engine valve system comprises two cams (10,12) mounted coaxially, a summation rocker (14) coupled to followers (16,18) of both cams and movable in proportion to the instantaneous sum of the lifts of the respective cams, and a valve actuating rocker (20) pivotably coupled to the summation rocker (14) and operative to open an engine valve (22) in dependence upon the movement of the summation rocker (14). In the invention, the actuating rocker (20) rests on a hydraulic lash adjuster (24). A control spring (136) is provided to urge the summation rocker (14) in a direction to compress the hydraulic lash adjuster (24). A stop (138) associated with the control spring (136) limits the movement of the summation rocker (14) towards the lash adjuster (24) so as to set the clearance in the valve system when the valve (22) is closed and the cam followers (16,18) are on the base circles of the two cams (10,12).

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 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 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: 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 has intake (20) and exhaust (22) poppet valves, a first and a second set of cam lobes (64) for operating the intake and exhaust poppet valves (20,22) respectively, and a third set of cam lobes (68) for producing an additional selectable valve event in order to allow the engine to operate as a compression brake. The third set of cam lobes (68) and at least one of the first and second set of cam lobes (64) are rotatable relative to one another and form part of an assembled camshaft (60) so as to be rotatable about a common axis. A phasing system (50) acts on the assembled camshaft (60) to allow the phase of the third set of cam lobes (68) to be changed relative to the engine crankshaft.