Abstract: A valve actuation system comprises a first arm having a first arm contact surface and operatively connected to a valve actuation motion. A second arm having a second arm contact surface is operatively connected to the at least one engine valve. A discrete lost motion device is provided that is controllable between a first, motion conveying state and a second, motion absorbing state. The discrete lost motion devices comprises a plunger contact surface and a housing contact surface. The housing contact surface is configured to engage one of the first or second arm contact surfaces, and the plunger contact surface is configured to engage another of the first and the second arm contact surfaces. The first and second arm contact surfaces, the housing contact surface and the first plunger contact surface are configured to support the discrete lost motion device between the first arm and the second arm.

Abstract: A discrete lost motion device for use in a valve train of an internal combustion engine comprises a housing having a housing bore extending longitudinally into the housing and a second end having a housing contact surface configured to engage a corresponding contact surface of a first valve train component. A plunger slidably is disposed in the housing bore is controllable between a first state in which the plunger rigidly extends out of the housing bore and a second state in which the plunger is permitted to reciprocate within the housing bore, the plunger further comprising an end having a plunger contact surface configured to engage a corresponding contact surface of a second valve train component. The housing contact surface and the plunger contact surface are configured to support the discrete lost motion device between the first and second valve train components.

Abstract: Valve bridge systems include constraints and guides for managing bridge jump and other uncontrolled valve bridge motion during engine operation. Constraints may include an e-foot collar, an extended portion on the bridge, and a bridge brake pin. Guides may include valve stem tip lead-in chamfers surrounding the valve bridge valve pockets as well as a deflection surface on the bridge extended portion. Methods of configuring valve bridges may include configuring the valve step tip lead-in chamfers based on worst-case positions of the valve bridge defined by one or more or a combination of the constraints provided by the e-foot collar, extended portion and brake pin.

Abstract: A valve actuation system includes a rocker for conveying motion to an engine valve, a motion source arranged to impart motion to the rocker, rocker stop assembly configured to operate in an activated mode, in which the rocker stop assembly maintains the rocker in a position corresponding to partial valve lift, and a deactivated mode, in which the rocker stop assembly allows the rocker to move to a position corresponding to a fully closed valve position, and a rocker stop reset assembly for resetting the rocker stop assembly to the deactivated mode subsequent to a main event peak lift to thereby achieve late valve closing. A damper assembly may interact with the rocker stop assembly to provide a smooth transition of the rocker and valve motion to a late intake valve closing dwell. A valve catch assembly may control the seating velocity of the at least one valve.

Abstract: Valve bridge systems include constraints and guides for managing bridge jump and other uncontrolled valve bridge motion during engine operation. Constraints may include an e-foot collar, an extended portion on the bridge, and a bridge brake pin. Guides may include valve stem tip lead-in chamfers surrounding the valve bridge valve pockets as well as a deflection surface on the bridge extended portion. Methods of configuring valve bridges may include configuring the valve step tip lead-in chamfers based on worst-case positions of the valve bridge defined by one or more or a combination of the constraints provided by the e-foot collar, extended portion and brake pin.

Abstract: A valve actuation system comprises a valve actuation motion source configured to provide a main valve actuation motion and an auxiliary valve actuation motion for actuating at least one engine valve via a valve actuation load path. A lost motion subtracting mechanism is arranged in the valve actuation load path and configured, in a first default operating state, to convey at least the main valve actuation motion and configured, in a first activated state, to lose the main valve actuation motion and the auxiliary valve actuation motion. Additionally, a lost motion adding mechanism configured, in a second default operating state, to lose the auxiliary valve actuation motion and configured, in a second activated state, to convey the auxiliary valve actuation motion, wherein the lost motion adding mechanism is in series with the lost motion subtracting mechanism in the valve actuation load path at least during the second activated state.

Abstract: A system for controlling actuation of an engine valve comprises a pivot and a torsion spring having first and second legs operatively connected to the pivot. A lever arm is adjustably affixed to and extending away from the pivot, and is further rotatable about a pivot axis of the pivot between a retracted position and an extended position and vice versa relative to a motion conveying component. Furthermore, a housing is provided having a pivot bore formed therein with the pivot rotatably disposed in the pivot bore. The housing further comprises a first and second openings intersecting with the pivot bore such that the first and second legs extend out of the first opening and the lever arm extends out of the second opening. When a first force is applied by the motion conveying component to the lever arm, such first force maintains the lever arm in the extended position.

Abstract: A system for controlling actuation of an engine valve comprises a pivot and a torsion spring having first and second legs operatively connected to the pivot. A lever arm is adjustably affixed to and extending away from the pivot, and is further rotatable about a pivot axis of the pivot between a retracted position and an extended position and vice versa relative to a motion conveying component. Furthermore, a housing is provided having a pivot bore formed therein with the pivot rotatably disposed in the pivot bore. The housing further comprises a first and second openings intersecting with the pivot bore such that the first and second legs extend out of the first opening and the lever arm extends out of the second opening. When a first force is applied by the motion conveying component to the lever arm, such first force maintains the lever arm in the extended position.

Abstract: A compact, modular, lost motion variable valve actuation assembly includes a dry start hydraulic circuit to enable quick priming of a lost motion master-slave circuit from a dry start reservoir to the master piston chamber during engine start. Motion of the master piston on engine startup may draw in fluid from the dry start hydraulic circuit. The dry start components may be integrated into a compact modular rocker shaft pedestal package suitable for retrofit on existing engine head assemblies. The master piston may include a push tube interface that includes a deep push tube cavity and lubrication capabilities in the master piston that provides for improved wear, stability, easy installation and alignment. The slave piston may be provided with a valve catch to reduce valve closing velocity during cycles involving lost-motion.

Abstract: A valve bridge comprises a central body and at least first and second valve interface portions extending from the central body, each of the at least first and second valve interface portions defining a chamber configured to receive an engine valve and corresponding valve spring and spring retainer. Each chamber comprises a valve bridge control surface configured to selectively contact at least one of the corresponding valve spring and spring retainer, wherein each valve bridge control surface is a concave surface configured to extend downward around the corresponding valve spring.

Abstract: A compact, modular, lost motion variable valve actuation assembly includes a dry start hydraulic circuit to enable quick priming of a lost motion master-slave circuit from a dry start reservoir to the master piston chamber during engine start. Motion of the master piston on engine startup may draw in fluid from the dry start hydraulic circuit. The dry start components may be integrated into a compact modular rocker shaft pedestal package suitable for retrofit on existing engine head assemblies. The master piston may include a push tube interface that includes a deep push tube cavity and lubrication capabilities in the master piston that provides for improved wear, stability, easy installation and alignment. The slave piston may be provided with a valve catch to reduce valve closing velocity during cycles involving lost-motion.

Abstract: A system and associated methods for controlling valve motion in internal combustion engines provide a pulsing component for energizing a solenoid control valve in pulsatile fashion to cause a transient pressure change in a hydraulic network linking the control valve to a common, paired set of intake and exhaust main event deactivation mechanisms, which may be provided in respective valve bridges. The pressure change results in hydraulic deactivation of main event motion of the exhaust valve while avoiding deactivation of main intake event motion and thereby preserving intake main event valve motion, and supporting use of the intake main event motion for additional braking or other operations. The systems and methods are particularly suited for engine environments that employ cylinder deactivation (CDA) combined with high-power density (HPD) engine braking.

Abstract: A valve bridge comprises a central body and at least first and second valve interface portions extending from the central body, each of the at least first and second valve interface portions defining a chamber configured to receive an engine valve and corresponding valve spring and spring retainer. Each chamber comprises a valve bridge control surface configured to selectively contact at least one of the corresponding valve spring and spring retainer, wherein each valve bridge control surface is a concave surface configured to extend downward around the corresponding valve spring.

Abstract: A system and associated methods for controlling valve motion in internal combustion engines provide a pulsing component for energizing a solenoid control valve in pulsatile fashion to cause a transient pressure change in a hydraulic network linking the control valve to a common, paired set of intake and exhaust main event deactivation mechanisms, which may be provided in respective valve bridges. The pressure change results in hydraulic deactivation of main event motion of the exhaust valve while avoiding deactivation of main intake event motion and thereby preserving intake main event valve motion, and supporting use of the intake main event motion for additional braking or other operations. The systems and methods are particularly suited for engine environments that employ cylinder deactivation (CDA) combined with high-power density (HPD) engine braking.

Abstract: A valve actuation system comprises a valve actuation motion source configured to provide a main valve actuation motion and an auxiliary valve actuation motion for actuating at least one engine valve via a valve actuation load path. A lost motion subtracting mechanism is arranged in the valve actuation load path and configured, in a first default operating state, to convey at least the main valve actuation motion and configured, in a first activated state, to lose the main valve actuation motion and the auxiliary valve actuation motion. Additionally, a lost motion adding mechanism configured, in a second default operating state, to lose the auxiliary valve actuation motion and configured, in a second activated state, to convey the auxiliary valve actuation motion, wherein the lost motion adding mechanism is in series with the lost motion subtracting mechanism in the valve actuation load path at least during the second activated state.

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 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: 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.