Abstract: A combined dedicated braking and EEVO lost motion valve actuation systems for internal combustion engines provide subsystems for braking events and EEVO events on one or more cylinders. Various control strategies may utilize braking and EEVO capabilities to module one or more engine parameters, including aftertreatment temperature and engine load.

Abstract: Systems and methods for internal exhaust gas recirculation (iEGR) in internal combustion engines may utilize secondary intake valve lift events during an exhaust valve main event in lost motion valve actuation systems. The secondary intake valve lift event may occur at the beginning or end of the exhaust valve main event. Favorable intake valve lift profiles are obtained with the use of a reset component, which may perform a hydraulic reset on the lost motion component in order to ensure that the intake valve secondary lift event occurs optimally near the beginning of an exhaust valve main event. The reset component may be triggered using motion from an exhaust valvetrain, for example, by a triggering component such as a reset pad, on an exhaust rocker. The reset component may also be triggered on the basis of the intake rocker arm position, in which case a reset pad that is fixed to the engine head or fixed relative to the intake rocker motion may be used.

Abstract: A valve actuation system comprises a first motion transfer mechanism operatively connected to a first valve actuation motion source and to the at least one engine valve, a second motion transfer mechanism operatively connected to a second valve actuation motion source; and a selectable coupling mechanism between the first and second motion transfer mechanisms. The coupling mechanism is operable in a first state where first valve actuation motions are conveyed to the at least one engine valve via the first motion transfer mechanism, and a second state where second valve actuation motions are additionally conveyed to the at least one engine valve via the second motion transfer mechanism, the coupling mechanism and the first motion transfer mechanism. During a handoff between the first and second valve actuation motions or vice versa, a difference in valve actuation velocities of the first and second valve actuation motions does not exceed a threshold.

Abstract: A switching finger follower for an engine valve train utilizes an adjustable support assembly that eliminates potential for partial engagement during operation. A lever engagement member or latch is disposed for movement on the follower body and interacts with a lever to provide a constant contact geometry. The finger follower may be configured as a lost motion device and may include a biasing assembly and a travel limiter. The latch may support the lever in at least one precise position and may support the lever in a second position for partial lost motion, or permit the lever to pivot free of the latch for complete lost motion, as in cylinder deactivation applications.

Abstract: A valve bridge system comprises a valve bridge configured to extend between at least two engine valves of an internal combustion engine. In one embodiment, a valve bridge guide is operatively connected to the valve bridge and configured to extend between at least two valve springs respectively corresponding to the at least two engine valves, the valve bridge guide defining a surface conforming to a valve spring of the at least two valve springs. In another embodiment, the valve bridge guide may comprise at least a first member maintained in a first fixed position relative to and at a predetermined distance from the valve bridge. In both embodiments, the valve bridge guide is configured to avoid contact with the valve bridge in a controlled state, but to permit contact with valve bridge to resist uncontrolled movement of the valve bridge.

Abstract: A valve bridge system comprises a valve bridge configured to extend between at least two engine valves of an internal combustion engine. In one embodiment, a valve bridge guide is operatively connected to the valve bridge and configured to extend between at least two valve springs respectively corresponding to the at least two engine valves, the valve bridge guide defining a surface conforming to a valve spring of the at least two valve springs. In another embodiment, the valve bridge guide may comprise at least a first member maintained in a first fixed position relative to and at a predetermined distance from the valve bridge. In both embodiments, the valve bridge guide is configured to avoid contact with the valve bridge in a controlled state, but to permit contact with valve bridge to resist uncontrolled movement of the valve bridge.

Abstract: Systems for valve actuation in internal combustion engines provide configurations for collapsing valve train components, particularly collapsing valve bridges. Various configurations for locking a bridge piston to a bridge housing include substantially cylindrical locking pins that may be housed within a substantially cylindrical receptacles defined by a transverse bore in the bridge piston and actuated hydraulically and may include an actuating pin that interacts with the locking pins to synchronize motion and provide positive positioning within an annular recess in the bridge housing to lock or unlock the bridge piston for movement relative to the bridge housing. Various geometries for locking pins and actuating pins provide benefits of manufacturing, ease of assembly, alignment and reduced wear.

Abstract: A system for actuating one or more engine valves for positive power operation and engine braking operation is disclosed. In a preferred embodiment, an exhaust valve bridge and intake valve bridge each receive valve actuations from two sets of rocker arms. Each valve bridge includes a sliding pin for actuating a single engine valve and an outer plunger disposed in the center of the valve bridge to actuate two engine valves through the bridge. The outer plunger of each valve bridge may be selectively locked to its valve bridge to provide positive power valve actuation. During engine braking, application of hydraulic pressure to the outer plungers may cause the respective valve bridges and outer plungers to unlock so that all engine braking valve actuations are provided from a rocker arm acting on one engine valve through the sliding pin.

Abstract: Variable-length assemblies, including lost motion assemblies eliminate hydraulic or pneumatic working fluids for operation in internal combustion engine valve trains and may be integrated into valve rocker arm pivots. An example piston and actuating plate are provided with working surfaces that interact when the actuating plate is rotated relative to the piston. The working surfaces include ramped transition portions and may include upper and lower flat portions. A shallow ramp angle prevents counter-rotation of the actuating plate under load. Actuating assemblies include an actuating solenoid includes a plunger that engages and pivots the actuating arm to cause rotation of the actuating plate relative to the piston and changes the state of the lost motion assembly from an “off” state, where motion may be absorbed, to an “on” state where the lost motion assembly is rigid and does not absorb motion.

Abstract: Systems and methods for managing excessive intake flow path pressure and counter flow are implemented to support enhanced engine braking applications, such as 2-stroke or 1.5-stroke engine braking implementations where the intake flow path may be exposed to excessive transient pressures in the combustion chamber during activation or deactivation of an engine brake. Intake throttle, exhaust gas recirculation (EGR) valve, intake manifold blow-off valve, compressor bypass valve, exhaust throttle, turbocharger geometry or turbocharger waste gate may be controlled to effectuate counter flow management separately or in combination. Excessive transient conditions may also be prevented or managed by sequential valve motion in which brake motion activation occurs first and then exhaust valve main event deactivation occurs second. Delay between brake activation and main event deactivation may be facilitated using mechanical and/or hydraulic implements as well as electronically.

Abstract: A system for supplying hydraulic fluid in an internal combustion engine comprises a pumping assembly disposed within a housing and a hydraulic circuit, operatively connected to the pumping assembly, also disposed within the housing, which housing may be fixed or dynamic. A source of pumping motions is operatively connected to the pumping assembly, which source of pumping motions may comprise a valve actuation motion source or a component of a valve train between the valve actuation motion source and an engine valve. Pumping motions applied to the pumping assembly by the source of pumping motions causes hydraulic fluid received from a supply pressure hydraulic fluid input of the hydraulic circuit to be transmitted to an increased pressure hydraulic fluid output of the hydraulic circuit.

Abstract: A system for actuating engine valves may include a valve bridge having a main event rocker interface portion, a first valve interface portion and a second valve interface portion extending in generally opposite directions from the main event rocker interface portion. The second valve interface portion may include an open end including a slot for receiving a bridge pin. The slot permits the valve bridge to be removed from the actuation system without removal of the main event rocker or other actuating components, such as an auxiliary rocker. The valve bridge can be removed from the valve train without requiring removal of other actuation system components, such as auxiliary rockers or main event rockers. A single valve bridge configuration can be used with different valve spans, which may occur among different cylinder sizes in a given engine family, or across different engine families.

Abstract: A system for actuating engine valves may include a valve bridge having a main event rocker interface portion, a first valve interface portion and a second valve interface portion extending in generally opposite directions from the main event rocker interface portion. The second valve interface portion may include an open end including a slot for receiving a bridge pin. The slot permits the valve bridge to be removed from the actuation system without removal of the main event rocker or other actuating components, such as an auxiliary rocker. The valve bridge can be removed from the valve train without requiring removal of other actuation system components, such as auxiliary rockers or main event rockers. A single valve bridge configuration can be used with different valve spans, which may occur among different cylinder sizes in a given engine family, or across different engine families.

Abstract: Systems for valve actuation in internal combustion engines with a dedicated rocker for actuating the at least one of two or more engine valves in a braking operation may include a biasing component, such as a compression spring, tension spring, spring catch, hydraulic actuator, pneumatic actuator for biasing the dedicated rocker in a biased direction away from the motion source, and a limiting component, such as a physical stop including a set screw or a stop integrated in the biasing component, for limiting the motion of the dedicated rocker in the biased direction. The biasing component and limiting component maintain the dedicated rocker in a controlled state and a positive, neutral position during operation.

Abstract: In an internal combustion engine, a linkage is provided between an auxiliary motion source and a main motion load path, such that motions received by the linkage from the auxiliary motion source result in provision of a first force to at least one engine valve and a second force to the main motion load path in a direction toward a main motion source. Where an automatic lash adjuster is associated with the main motion load path, the second force may be selected to aid in the control of lash adjustments made by the automatic lash adjuster. In various embodiments, the linkage may be embodied in an mechanical linkage, whereas in other embodiments, an hydraulic linkage may be employed. The linkage may be incorporated into, or otherwise cooperate, a valve bridge or a rocker arm.

Abstract: Systems for valve actuation in internal combustion engines provide configurations for hydraulic lash adjusters and valve actuation valvetrain components that are particularly suitable for prevention of HLA jacking in lost motion cam environments and in valve bridge environments. In one implementation, a rocker arm may transmit motion from a lost motion cam having main event and auxiliary event lobes. Main event motion is transmitted to two engine valves through the rocker arm, a lash adjuster, lash adjuster loading component and valve bridge, which define part of a first load path. Braking motion is transmitted to one of the engine valves through an inboard valve actuator and bridge pin, which define part of a second load path. The HLA is thus disposed in a separate load path from the braking valve load and the lash adjuster loading component keeps the lash adjuster under a constant compressive force to prevent jacking.

Abstract: A system for actuating engine valve comprises a main valve actuation motion source configured to supply main valve actuation motions to the at least one engine valve via a main motion load path, and an auxiliary valve actuation motion source separate from the main valve actuation motion source and configured to supply complementary auxiliary valve actuation motions to the at least one engine valve via an auxiliary motion load path. A lost motion component is configured, in one state, to maintain lash between the auxiliary valve actuation motion source and the auxiliary motion load path or within the auxiliary motion load path and, in another state, to take up this lash. The auxiliary valve actuation motion source is further configured to supply at least one lash-prevention valve actuation motion that substantially matches at least one of the main valve actuation motions.

Abstract: A controller of an internal combustion engine receives a request to activate an exhaust brake subsystem and, in response thereto, activates the exhaust braking subsystem. The controller thereafter determines that at least one parameter of the exhaust system, an intake subsystem or both compares unfavorably with at least one threshold. When the at least one parameter compares unfavorably with the at least one threshold, the controller determines that the exhaust braking subsystem has failed. In embodiments, the determination that the at least one parameter compares unfavorably with the at least one threshold comprises a determination that backpressure in the exhaust system is lower than a backpressure threshold and/or a determination that boost pressure in the intake subsystem is higher than a threshold.

Abstract: A system that provides adjustable actuation timing of one or more valve(s) (16) in a piston engine includes a position sensor (12) and a variable valve actuation assembly (10). The valve(s) (16) can be intake and/or exhaust valves in an internal combustion engine of an automobile. The position sensor (12) takes position readings of the valve(s) (16) as the valve(s) (16) actuate in the piston engine. The variable valve actuation assembly (10) controls actuation timing of the valve(s) (16). Actuation timing of the valve(s) (16) is adjustable based, in part or more, upon one or more position reading(s) of the position sensor (12). The variable valve actuation assembly (10) can be a lost motion assembly (10).

Abstract: In an engine comprising a cylinder having first and second engine valves of a same function type, a system for actuating the first and second engine valves comprises a first and second master pistons that receive first and second valve actuation motions from respective ones of a first and second valve actuation motion source, a first slave piston operatively connected to the first engine valve and configured to hydraulically receive the first valve actuation motions from at least the first master piston and a second slave piston operatively connected to the second engine valve and configured to hydraulically receive the second valve actuation motions from the second master piston. The system further comprises an accumulator and a mode selector valve in hydraulic communication with the first master piston, the first slave piston and the accumulator. The mode selector valve may selectively hydraulically connect the first master piston to the accumulator.