Abstract: Systems and methods for providing partial bleeder braking engine valve actuation are disclosed. In an embodiment of the present invention, a cam may be provided with a main exhaust lobe, a partial bleeder lobe and an inner base circle portion between the two lobes. A rocker arm including an internal rocker passage may be operatively connected to the cam. The rocker arm may contact a valve bridge at a central portion. The valve bridge may be operatively connected to first and second engine valves at its first and second ends, respectively. A slave piston incorporated into the first end of the valve bridge and a master piston may be incorporated into the central portion of the valve bridge. A hydraulic circuit may be provided between the master and slave pistons. A bleed hole may be provided above the slave piston.

Abstract: Apparatus and methods for hydraulic valve actuation of engine valves are disclosed. An exemplary embodiment of the present invention may include a plurality of slave piston assemblies that impart motion to the engine valves, wherein the motion is operable to open and close the engine valves. A dual diameter master piston assembly may be used to drive the plurality of slave pistons. The dual diameter master piston assembly may be divided into two or more elements with, for example, a spring bias or a button and T-slot assembly to hold the two elements together.

Abstract: An engine valve actuation system for an internal combustion engine is disclosed. The valve actuation system may include a longitudinally extending link member pivotally attached to an engine member. A longitudinally extending finger follower may be pivotally attached to the link member. The finger follower may include first and second contact surfaces spaced longitudinally from each other. A lost motion piston may contact the first contact surface of the finger follower and an engine valve assembly may contact the second contact surface of the finger follower. A means for receiving valve actuation motion, such as a cam follower, may be incorporated into the finger follower. A valve seating device may contact a third contact surface located on the link member, and a biasing spring may contact a fourth contact surface on the finger follower.

Abstract: A control method for transitioning from positive power to engine braking (and vice-versa) is disclosed. This transition may be made using variable valve actuation and two-stroke braking. The process may involve three engine operation modes: positive power (i.e., firing or non-braking), engine braking, and transition between engine braking and positive power. The intake and exhaust valve actuations provided for each of the different modes of operation may be different from each other.

Abstract: Systems and methods of actuating engine valves using a hydraulic valve actuation system are disclosed. The valve actuation system includes a master piston and two slave pistons slidably disposed in bores provided in a housing. The master piston and two slave pistons are connected together by a hydraulic circuit. Linear motion imparted to the master piston is transferred to the two slave pistons via the hydraulic circuit. In turn, the two slave pistons may actuate one or more engine valves directly or through an intermediate valve bridge. A valve seating device may be provided to assist in seating the engine valves in embodiments where the valve actuation system is adapted to provide variable valve actuation.

Abstract: Systems and methods for hydraulic and/or variable valve actuation of engine valves are disclosed. An embodiment of the present invention may include a hydraulic valve actuation system operatively connected to an engine valve. First and second control valves may be operatively connected to the hydraulic valve actuation system and adapted to selectively release hydraulic fluid from the hydraulic valve actuation system independent of one another. The first control valve is preferably a solenoid actuated trigger valve and the second control valve is preferably a mechanically or hydraulically actuated valve.

Abstract: Systems and methods of actuating two engine valves associated with a common engine cylinder using one or more lost motion systems and one or more control valves are disclosed. The control valves are capable of selectively trapping hydraulic fluid in the lost motion systems for auxiliary engine valve actuations and selectively releasing the hydraulic fluid to default to cam controlled valve seating of the engine valves. The systems may provide a combination of main exhaust, compression release, exhaust gas recirculation and early exhaust valve opening in preferred embodiments.

Abstract: A system and method for actuating one or more engine valves is provided. In particular, systems and methods for providing variable valve actuation to improve engine performance are provided. Embodiments of the present invention may be used in conjunction with positive power, engine braking, and/or exhaust gas recirculation operation of an internal combustion engine. In one embodiment, the system comprises: a valve train element; a housing disposed intermediate the valve train element and the engine valve; an outer piston slidably disposed in a bore formed in the housing, the outer piston having a cavity formed therein; an inner piston slidably disposed in the outer piston cavity; and a valve in communication with the outer piston cavity, the valve having more than one position, wherein the position of the valve determines the timing of the engine valve event.

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: An apparatus and method of controlling exhaust pressure in an internal combustion engine are disclosed. In one embodiment the apparatus may comprise: a housing; a valve disposed in the housing; an orifice formed in the valve, wherein the orifice defines a gas flowpath through the valve; and a shaft slidably disposed in a bore formed in the valve, the shaft movable between a first position, in which gas is substantially prevented from flowing through said orifice, and a second position in which gas is permitted to flow through said orifice. The position of the shaft may be selectively varied in response to an actuating force.

Abstract: Methods and apparatus for actuating an engine valve provided between an engine cylinder and an exhaust manifold to provide compression-release engine braking in combination with exhaust gas restriction and brake gas recirculation are disclosed. In a first embodiment of the present invention, the engine valve used to provide brake gas recirculation and compression-release braking may be maintained slightly open between the brake gas recirculation and compression-release events. In another embodiment of the present invention, the cam closing ramp for a main exhaust event may be extended to terminate near the beginning of a brake gas recirculation event to facilitate refilling a hydraulic valve actuation system used to in association with the exhaust valve.

Abstract: An electromagnetic retarder system is disclosed. In one embodiment, the retarder system comprises: a shaft; a coil statically disposed on the shaft and having a hollow cylindrical shape; a yoke statically disposed on the shaft, the yoke having a first cylindrical surface and a second cylindrical surface, the second cylindrical surface disposed coaxial with said coil; at least one claw pole rotor mounted on the shaft, the at least one claw pole rotor formed of magnetic half wheels that taper into claws; and an induction drum disposed coaxial with the shaft and mounted so as to encompass the coil, the yoke and the at least one rotor.

Abstract: A method for actuating one or more exhaust valves in an internal combustion engine during positive power operation is disclosed. The expansion stroke of an engine cylinder is effectively lengthened and the exhaust stroke is effectively shortened by delaying the opening and/or advancing the closing of the exhaust valve relative to conventional exhaust valve timing during the exhaust stroke. Selective variation of the exhaust stroke during positive power operation of the engine may reduce NOx production.

Abstract: Methods and apparatus for providing bleeder-type and compression-release engine braking in an internal combustion engine are disclosed. For bleeder-type engine braking, the exhaust valve is maintained at a small and relatively constant lift throughout all or much of the engine cycle. The engine braking may be combined with exhaust gas recirculation, variable exhaust brake, and/or operation of a variable geometry turbocharger.

Abstract: A variable valve actuation system to actuate and control the seating velocity of an internal combustion engine valve is disclosed. The system comprises: a housing; a lost motion system disposed in the housing; a rocker arm having a first contact surface, a second contact surface, and a third contact surface, the first contact surface operatively contacting the engine valve, and the second contact surface operatively contacting the lost motion system; and a valve seating device disposed in the housing, operatively contacting the third contact surface.

Abstract: A lost motion engine valve actuation system and method of actuating an engine valve are disclosed. The system may comprise a valve train element, a pivoting lever, a control piston, and a hydraulic circuit. The pivoting lever may include a first end for contacting the control piston, a second end for transmitting motion to a valve stem and a means for contacting a valve train element. The amount of lost motion provided by the system may be selected by varying the position of the control piston relative to the pivoting lever. Variation of the control piston position may be carried out by placing the control piston in hydraulic communication with a control trigger valve and one or more accumulators. Actuation of the trigger valve releases hydraulic fluid allowing for adjustment of the control piston position. Means for limiting valve seating velocity, filling the hydraulic circuit upon engine start up, and mechanically locking the control piston/lever for a fixed level of valve actuation are also disclosed.

Abstract: Devices for modifying engine valve lift during an engine valve event are disclosed. In one embodiment, the device comprises: a housing having a hydraulic fluid dump port formed therein; a sleeve slidably disposed in a bore formed in the housing, the sleeve having a cavity formed therein; a piston slidably disposed in the sleeve cavity; and a clip passage formed in the piston, the clip passage in selective communication with the dump port.

Abstract: Lost motion systems and methods for providing engine valves with variable valve actuation for engine valve events are disclosed. The system may include a master piston hydraulically linked to a slave piston, and a dedicated cam operatively connected to the master piston. The slave piston may be disposed substantially perpendicular to the master piston in a common housing. The slave piston is adapted to actuate one or more engine valves. The slave piston may incorporate an optional valve seating assembly into its upper end. A trigger valve may be operatively connected to the master-slave hydraulic circuit to selectively release and add hydraulic fluid to the circuit.

Abstract: A system and method for actuating at least one engine valve in an internal combustion engine to produce an engine valve event is disclosed. The system of the present invention may comprise: means for imparting motion to the at least one engine valve for producing the engine valve event; primary means for transmitting the motion from the motion imparting means to the at least one engine valve; and auxiliary means for transmitting the motion from the motion imparting means to the at least one engine valve. The auxiliary means may actuate the at least one engine valve only when the primary means is shut-off or fails.

Abstract: An apparatus and method for effectuating multi-cycle engine braking is disclosed. The present invention controls the operation of the engine valves to permit more than one compression release event during a single engine operating cycle. The apparatus includes an assembly for operating at least one exhaust valve of an engine cylinder during a positive power operation. The apparatus further includes an assembly for operating at least one intake valve of the engine cylinder. The apparatus further including an assembly for operating the at least one exhaust valve during an engine braking operation.