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 improvement is disclosed for an engine valve system with variable lift and duration of the type that includes two cams mounted coaxially, a summation rocker coupled to cam followers in contact with both cams and movable in proportion to the instantaneous sum of the lifts of the respective cams, and a valve actuating rocker pivotably coupled to the summation rocker and serving to open an engine valve in dependence upon the movement of the summation rocker. In the invention, at least one of the couplings of the summation rocker with the cam followers and with the valve actuating rocker incorporates an adjustable eccentric which is rotatable to enable the clearance within the valve system to be set.

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 assembly is disclosed which comprises an SCP camshaft 130 and a phaser mounted at one end of the SCP camshaft. The phaser has a stator 112 driven by an engine crankshaft and two output members 114, 116 each fast in rotation with a respective one of the inner shaft 140 and the outer tube 126 of the SCP camshaft 130. Two timing features 160, 172 are provided for enabling respective sensors to determine the angular positions of the inner shaft and the outer tube of the SCP camshaft. In the invention, both timing features 160, 172 are located on the side of the stator 112 remote from the camshaft 130.

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 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: An engine cylinder head 10 is disclosed having a first camshaft 14 driven by the engine crankshaft via a phasing system 12 mounted to the camshaft 14. A second camshaft 22 is driven via the phasing system 12 mounted to the first camshaft, and two oil control valves 46, 48 are connected to the phasing system for enabling the phasing system to vary the timing of each camshaft independently with respect to the engine crankshaft in response to oil pressure signals from a respective one of the control valves. In the invention, oil feeds from each control valve 46, 48 enter the camshaft 14 via an oil feed journal 34, 36, and connect to the phaser 12 via axially extending channels within the camshaft 14.

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.

Abstract: An improvement is disclosed for an engine valve system with variable lift and duration of the type that includes two cams mounted coaxially, a summation rocker coupled to cam followers in contact with both cams and movable in proportion to the instantaneous sum of the lifts of the respective cams, and a valve actuating rocker pivotably coupled to the summation rocker and serving to open an engine valve in dependence upon the movement of the summation rocker. In the invention, at least one of the couplings of the summation rocker with the cam followers and with the valve actuating rocker incorporates an adjustable eccentric which is rotatable to enable the clearance within the valve system to be set.

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: An internal combustion engine is described having a valve mechanism that comprises two cams (120,122) mounted coaxially and a summation lever (124) having cam followers (126, 127) in contact with both cams so as to move in proportion to the instantaneous sum of the lifts of the respective cams. A control spring (128) is provided to maintain contact between one cam profile and its respective follower(s), and a valve actuator (114) opens the engine valve (110) in dependence upon the movement of the summation lever, thereby enabling so as to enable the valve timing, valve lift and valve event duration to be adjusted by varying the phases of the two cams. In the invention, the summation lever is constructed in two parts (124a, 124b) that can be selectively locked and unlocked to allow the valve lift to be deactivated and the motion of both parts is controlled by the control spring (128) when the two parts of the summation lever are unlocked from one another.

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.

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: 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: An engine cylinder head 10 is disclosed having a first camshaft 14 driven by the engine crankshaft via a phasing system 12 mounted to the camshaft 14. A second camshaft 22 is driven via the phasing system 12 mounted to the first camshaft, and two oil control valves 46, 48 are connected to the phasing system for enabling the phasing system to vary the timing of each camshaft independently with respect to the engine crankshaft in response to oil pressure signals from a respective one of the control valves. In the invention, oil feeds from each control valve 46, 48 enter the camshaft 14 via an oil feed journal 34, 36, and connect to the phaser 12 via axially extending channels within the camshaft 14.