An apparatus (201) and method for controlling intake valves (23) in an internal combustion engine (5), as well as an internal combustion engine and a vehicle comprising the apparatus, and an electronic processor for performing the method is disclosed. The apparatus comprises a hydraulic system (3) configured to hydraulically actuate a first intake valve (23a) and a second intake valve (23b) of a first combustion chamber (25) of an internal combustion engine (5). The apparatus also includes a controller (9) configured to control the hydraulic system (3) in at least a first mode of operation and a second mode of operation. In the first mode of operation, the controller (9) is configured to control the hydraulic system (3) to cause lifting of the first and second intake valves (23a, 23b) of the first combustion chamber (25) during each intake stroke of a respective cylinder piston (27). In the second mode of operation, the controller (9) is configured to control the hydraulic system (3) to cause lifting of the first intake valve (23a) of the first combustion chamber (25) during an intake stroke of the respective cylinder piston (27) and disable actuation of the second intake valve (23b) of the first combustion chamber (25) during that intake stroke.

A variable valve train with at least two functionally identical gas-exchange valves per cylinder, having primary cam and a secondary cam generated valve strokes that are transmitted by a switchable cam follower selectively to the gas-exchange valves. The respective cam follower has a primary lever in tapping contact with the primary cam and in switching contact with the gas-exchange valve and a secondary lever that is in tapping contact with the secondary cam and is coupleable with the primary lever by a control pin. The respective control pins are connected by connecting elements to respective first and second elongated switching elements, which are arranged above the cam followers parallel to the camshaft and are displaceable longitudinally by a linear actuator from a home into a switched position. The control pins of the cam follower of functionally identical gas-exchange valves are in switching connection with a respective one of the first and second elongated switching elements for common movement.

Methods and systems are provided for extending a duration of engine idle-stop while reducing a frequency of engine restart from idle-stop. In one example, in response to engine restart conditions where combustion torque is not necessary, an engine can be rotated electrically, without fuel delivery, via an electric motor. The unfueled engine spinning via the motor drives an FEAD which in turns drives an actuator coupled to the FEAD, such as an AC compressor or an automatic transmission oil pump.

An exhaust valve rocker arm assembly operable in a combustion engine mode and an engine braking mode, the exhaust valve rocker arm assembly selectively opening first and second exhaust valves and including a rocker shaft, exhaust valve rocker arm assembly and a ball engine brake mechanism. The exhaust valve rocker arm assembly has an exhaust rocker arm that receives the rocker shaft and is configured to rotate around the rocker shaft. The ball engine brake mechanism is configured on the exhaust rocker arm and selectively actuates a valve plunger causing an exhaust valve to perform engine braking. The ball engine brake mechanism includes a capsule assembly having a capsule, a biasing member and a ball. The capsule has a cylindrical body that extends between a first end having an actuation face and a second end having a spring return face.

An internal combustion engine defining at least one cylinder, the internal combustion engine including a first camshaft lobe, a second camshaft lobe, a valve in fluid communication with the at least one cylinder, a pivot, and a follower in contact with and operatively engages the pivot, the valve, the first camshaft lobe, and the second camshaft lobe. During use, the follower is operable in a first mode, in which the follower is configured to transmit motion between the first camshaft lobe and the valve, and a second mode, in which the follower is configured to transmit motion between the first camshaft lobe and the valve and the second camshaft lobe and the valve.

An exhaust valve rocker arm for an exhaust valve rocker arm assembly operable in a combustion engine drive mode and an engine braking mode, and configured to selectively open first and second exhaust valves, includes a body defining an aperture to receive a rocker shaft such that the body is rotatable about the rocker shaft, a bore defined in the body, and a rotating stepped engine brake capsule disposed in the bore and having a castellation mechanism. The rotating stepped engine brake capsule is movable between a locked, engine brake active position and an unlocked, engine brake inactive position.

A control system for internal combustion engines having four valves per cylinder. An inlet valve and an exhaust valve are controlled by a basic camshaft. Another inlet valve and another exhaust valve are controlled by a control camshaft. The two camshafts are connected to a crankshaft and engine torque is managed by an electronic control unit. The system comprises a motor/generator unit, connected to the control camshaft; a differential, connected to the crankshaft and to the control camshaft; a control shaft, connected to the differential; an actuator, connected to the control shaft; a one-way restrictor valve connected to a shut-off valve and to the actuator; an oil circuit, connected to the actuator by means of the shut-off valve and a control solenoid that acts on the shut-off valve.

A variable valve train (1) of a combustion engine for applying a load on two equally acting gas exchange valves (2, 3) for each cylinder of the combustion engine is provided, including a switchable valve train element (4, 5) with an outer part and an inner part ((6, 7), (8, 9)) that can move relative to each other allocated to each of the two gas exchange valves (2, 3). The outer and inner parts ((6, 7), (8, 9)) are selectively connectable to each other by an associated coupling slide mechanism (10, 11). The valve train (1) further includes a control shaft (12), on which a control cam (13, 14) is applied for each coupling slide mechanism (10, 11), and the control cams contact an outer end face (15, 16) of the respective coupling slide mechanisms (10, 11) for displacement thereof in one direction, and the two control cams (13, 14) can rotate separately from each other on the common control shaft (12).

Hydraulic systems in an engine valvetrain having lost motion and/or braking hydraulic circuits are provided with a conditioning circuit that may include a supplemental supply passage, which provides continuous and supplemental supply of hydraulic fluid from a supply source to the braking and lost motion circuits, as well as a venting of the circuits to ambient, such that the hydraulic fluid in these circuits is kept in a refreshed and conditioned state without air contamination. A vented three-way solenoid valve may be utilized. The supplemental supply passage may be provided at various locations in the valvetrain and in the engine head environment. The supplemental supply passage may include flow and pressure control devices to control the flow of the supplemental supply of hydraulic fluid.

A valvetrain assembly has valves each having a valve stem; a main camshaft with main cams, a main cam corresponding to each valve; main rocker arms each corresponding to a valve and having a valve stem actuation portion, a pivot axis parallel to the main cam shaft, and a main cam follower for following the corresponding main cam, wherein the valve stem actuation portion, pivot axis, and main cam follower are arranged along the main rocker arm length distanced from each other; an auxiliary cam on the main camshaft; an auxiliary cam follower for each auxiliary cam, following the auxiliary cam, wherein each auxiliary cam follower is movable on one main rocker arm between a first and second position; a latch on respective main rocker arm(s) for locking the auxiliary cam follower in the first position; and an auxiliary camshaft with a selector cam for each latch, controlling the latch.