Abstract: Apparatus and methods for hydraulic valve actuation of engine valves are disclosed. An exemplary embodiment of the present invention may include a lost motion piston assembly that transfers motion between first and second rocker arms to selectively provide auxiliary engine valve actuation motions to the engine valves for engine operations such as engine braking and exhaust gas recirculation. The lost motion piston assembly may reduce or eliminate transient loads that may otherwise be transmitted to engine valve train elements during the times that lost motions systems are turned on and off for auxiliary valve actuations.

Abstract: Systems and methods for actuating engine valves are disclosed. The systems may include primary and auxiliary rocker arms disposed adjacent to each other on a rocker arm shaft. The primary rocker arm may actuate an engine valve for primary valve actuation motions, such as main exhaust events, in response to an input from a first valve train element, such as a cam. The auxiliary rocker arm may receive one or more auxiliary valve actuation motions, such as for engine braking, exhaust gas recirculation, and/or brake gas recirculation events, from a second valve train element. A hydraulic actuator piston may be disposed between the auxiliary rocker arm and the primary rocker arm. The actuator piston may be selectively locked into an extended position between the primary and auxiliary rocker arms so as to selectively transfer the one or more auxiliary valve actuation motions from the auxiliary rocker arm to the primary rocker arm.

Abstract: A system and method for actuating one or more engine valves to produce an engine valve event is disclosed. The system may comprise: a housing; an accumulator disposed in the housing having a first open end and a second open end; a master piston slidably disposed in a first bore formed in the housing; a valve train element(s) for imparting motion to the master piston; and a slave piston slidably disposed in a second bore formed in the housing, the slave piston in fluid communication with the master piston through a high pressure hydraulic passage, wherein the first open end and the second open end of the accumulator are in communication with the high pressure hydraulic passage to selectively modify the imparted motion.

Abstract: Systems and methods for actuating engine valves are disclosed. The systems may include primary and auxiliary rocker arms disposed adjacent to each other on a rocker arm shaft. The primary rocker arm may actuate an engine valve for primary valve actuation motions, such as main exhaust events, in response to an input from a first valve train element, such as a cam. The auxiliary rocker arm may receive one or more auxiliary valve actuation motions, such as for engine braking, exhaust gas recirculation, and/or brake gas recirculation events, from a second valve train element. A hydraulic actuator piston may be disposed between the auxiliary rocker arm and the primary rocker arm. The actuator piston may be selectively locked into an extended position between the primary and auxiliary rocker arms so as to selectively transfer the one or more auxiliary valve actuation motions from the auxiliary rocker arm to the primary rocker arm.

Abstract: A system and method of actuating one or more engine valves is disclosed. In one embodiment, the system comprises: a valve train element; a rocker arm pivotally mounted on a shaft and adapted to rotate between a first position and a second position, the rocker arm selectively receiving motion from the valve train element; a valve bridge disposed above the one or more engine valves; and a lost motion system disposed in the valve bridge.

Abstract: A system and method for actuating one or more engine valves to produce an engine valve event is disclosed. The system may comprise: a housing; an accumulator disposed in the housing having a first open end and a second open end; a master piston slidably disposed in a first bore formed in the housing; a valve train element(s) for imparting motion to the master piston; and a slave piston slidably disposed in a second bore formed in the housing, the slave piston in fluid communication with the master piston through a high pressure hydraulic passage, wherein the first open end and the second open end of the accumulator are in communication with the high pressure hydraulic passage to selectively modify the imparted motion.

Abstract: A gas recirculation system is disclosed for improving engine braking in an internal combustion engine having an intake valve, an exhaust valve, and a cylinder. The system includes an exhaust manifold operatively connected to the cylinder through the exhaust valve; an intake manifold operatively connected to the cylinder through the intake valve; and a gas recirculation passage adapted to recirculate gas from the exhaust manifold to the intake manifold during an engine braking event.

Abstract: A gas recirculation system is disclosed for improving engine braking in an internal combustion engine having an intake valve, an exhaust valve, and a cylinder. The system includes an exhaust manifold operatively connected to the cylinder through the exhaust valve; an intake manifold operatively connected to the cylinder through the intake valve; and a gas recirculation passage adapted to recirculate gas from the exhaust manifold to the intake manifold during an engine braking event.

Abstract: The present invention is directed to an innovative, economical method or system disclosing a captive volume in a hydraulic circuit which can be selectively hydraulically or pneumatically locked, or vented in order to correspondingly maintain, or increase the total volume of the hydraulic circuit. The structural elements of an embodiment of the present invention may include an accumulator with or without a fixed solid stop, which limits its travel. The accumulator can either be a separate entity, or as an assembly within the master or slave pistons.

Abstract: In an internal combustion engine comprising a gas recirculation passage connecting an exhaust manifold to an intake manifold, a compression release valve, and at least one gas pulse created during a first event, a method for retarding the engine comprising the steps of opening the compression release valve, releasing at least one gas pulse into the gas recirculation passage after a first event, redirecting the at least one gas pulse into the intake manifold, and using the at least one gas pulse to increase air charge in a cylinder.

Abstract: The present invention is directed to an innovative, economical method or system dislosing a captive volume in a hydraulic circuit which can be selectively hydraulically or pneumatically locked, or vented in order to correspondingly maintain, or increase the total volume of the hydraulic circuit. The structural elements of an embodiment of the present invention may include an accumulator with or without a fixed solid stop, which limits its travel. The accumulator can either be a separate entity, or as an assembly within the master or slave pistons.

Abstract: An internal combustion engine may include a hydraulic linkage used to transfer motion from a valve train element, such as a cam, to an engine valve. Method and apparatus for selectively limiting the motion transferred by the hydraulic linkage from the valve train element to the engine valve are disclosed. The motion transferred by the hydraulic linkage may be limited by a means for resetting or clipping that is integrated into the rocker arm/shaft assembly provided in the valve train.

Abstract: The present invention is directed to an innovative, economical method or system disclosing a captive volume in a hydraulic circuit which can be selectively hydraulically or pneumatically locked, or vented in order to correspondingly maintain, or increase the total volume of the hydraulic circuit. The structural elements of an embodiment of the present invention may include an accumulator with or without a fixed solid stop, which limits its travel. The accumulator can either be a separate entity, or as an assembly within the master or slave pistons.

Abstract: In an internal combustion engine comprising a gas recirculation passage connecting a first member to an intake manifold, a compression release means, and at least one gas pulse created during a first event, a method for retarding the engine comprising the steps of opening the compression release means, releasing at least one gas pulse into the gas recirculation passage after a first event, redirecting the at least one gas pulse into the intake manifold, and using the at least one gas pulse to increase air charge in a cylinder.

Abstract: An internal combustion engine may include a hydraulic linkage used to transfer motion from a valve train element, such as a cam, to an engine valve. Method and apparatus for selectively limiting the motion transferred by the hydraulic linkage from the valve train element to the engine valve are disclosed. The motion transferred by the hydraulic linkage may be limited by a means for resetting or clipping that is integrated into the rocker arm/shaft assembly provided in the valve train.