Abstract: This invention is an exhaust gas recirculation apparatus such that exhaust gas recirculation master piston (12) is activated and acts to open exhaust valve (4) on the same cylinder (1) by driving a slave piston (14), thus recirculating exhaust gas into combustion chamber (2) from exhaust port (5) as a result of the pressure difference, thereby lowering the combustion temperature within combustion chamber (2) on the next power stroke and working to reduce NOx. Moreover, by selectively maintaining and releasing oil pressure in two types of passages (13) and (31), it can also be used as a compression pressure-release engine brake.

Abstract: A lost motion valve actuation system for an internal combustion engine is disclosed. The system includes a motion feedback system (100) for detecting the motion and timing of a valve actuator (130) and an engine valve (140). By providing information on the condition of the engine during operation, the motion feedback system (100) permits adjustment of the valve actuation system that can optimize operation or prevent engine damage. The motion feedback system may be used in a common rail or a lost motion valve actuation system. In alternate embodiments, the valve actuation system includes an accumulator (300) with an accumulator piston (310) whose motion is limited by an accumulator stop (330) or a control valve (200). The limited accumulator (300) controls the amount of lost motion in the valve actuation system to provide fail-safe operation in the event of electrical failure.

Abstract: A system for decelerating a linearly displaceable valve undergoing a closing motion is disclosed. The system includes a housing, a first hydraulic fluid chamber provided in said housing, and a slave piston for displacing the valve in response to the supply of hydraulic fluid to the first hydraulic fluid chamber. Deceleration of the valve may be accomplished by selectively throttling the release of hydraulic fluid in the first chamber to a second chamber. The hydraulic pressure in the second chamber opposes the closing motion of the valve, thereby slowing it gently for a valve seating event. Progressive throttling is used to maintain nearly constant hydraulic pressure in the second chamber during the seating event. The progressive throttling may be accomplished by selection of an appropriate throttling orifice size and shape, as well as an appropriate throttling profile for the orifice.

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, pivoting bridge, an adjustable tappet, and a valve stem. The pivoting bridge may include a first end for contacting the adjustable tappet, a second end for contacting the valve stem and a pivot point between the first and second ends for contacting the valve train element. The amount of lost motion provided by the system may be selected by varying the position of the adjustable tappet relative to the pivoting bridge. Variation of the adjustable tappet position may be carried out by placing the adjustable tappet in hydraulic communication with a control trigger valve. Actuation of the trigger valve releases hydraulic fluid allowing for adjustment of the adjustable tappet position.

Abstract: An apparatus for limiting the travel of a slave piston (110) in a slave piston cylinder (100) in a compression release engine brake is disclosed. The apparatus provides stroke-limiting means and independent lash adjustment means which may be installed in a common rail, variable valve actuation system. The independent lash adjustment means comprises a sleeve (300) around the slave piston (110), threadably mounted in the brake housing (40). The stroke-limiting means comprises a slave piston (110) in a slave piston cylinder (100), a trigger valve (90) and a hydraulic circuit connected thereto. The slave piston stroke is limited when a lower flow port (130) in the slave piston cylinder (100) is opened to drain (81) slightly before high-pressure flow is cut off through an upper flow port (120) in the slave piston cylinder (100).

Abstract: A valve actuation system for an internal combustion engine is disclosed. The system includes two hydraulic plungers (master pistons) that are selectively hydraulically coupled to a slave piston. The hydraulic motion from one of the hydraulic plungers may provide a valve opening motion to the slave piston and the hydraulic motion from the other hydraulic plunger may provide a valve closing motion. The net hydraulic motion of both hydraulic plungers may be zero, so that when both plungers have hydraulic communication with the slave piston, no slave piston motion occurs. The system may provide full authority over all engine valve actuations, such as main intake, main exhaust, compression release, and exhaust gas recirculation.

Abstract: A lost motion variable valve actuation system utilizing a single solenoid valve or trigger valve to vary the timing of the intake and exhaust valves for a cylinder of an internal combustion engine. The solenoid controls the oil supply to the tappets, which in turn, determine valve motion in response to a camshaft lobe The system allows independent control of each valve and provides for advanced features such as enhanced intake air swirl, two-valve or four-valve operation and staggered valve opening. The invention provides for valve operation even in the event of a total loss of system hydraulic pressure. The invention provides the practical benefits of a fully-variable system while preserving the security and reliability of a mechanical, cam-driven valve train. The invention provides for filling the exhaust and intake tappets independently without connecting their respective hydraulic circuits.

Abstract: An internal combustion engine has electrically controlled hydraulic linkages between engine cams and engine cylinder valves. If it is desired to skip a cam lobe or to modify the response of an engine cylinder valve to a cam lobe, hydraulic fluid is selectively released from the associated hydraulic linkage to permit lost motion between the cam and the engine cylinder valve. Electrically controlled hydraulic fluid valves are used to produce the selective release of hydraulic fluid from the hydraulic linkages. The mode of operation of the engine can be changed (e.g., from positive power mode to compression release engine braking mode or vice versa), or more subtle changes can be made to modify the timing and/or extent of engine cylinder valve openings to optimize engine performance for various engine or vehicle operating conditions (e.g., different engine or vehicle speeds). The valves can be controlled to produce an exhaust gas recirculation event during various operating modes of the engine.

Abstract: A valve actuating assembly for actuating at least one valve is disclosed. The valve actuating assembly includes a housing assembly, an actuating assembly for actuating at least one valve during a first valve operating event and a second valve operating event, and an assembly for modifying valve motion travel of the at least one valve during at least one of the first valve operating event and the second valve operating event. A system for providing exhaust gas recirculation and compression release braking in an engine is also disclosed.

Abstract: An internal combustion engine valve actuation system is disclosed. The present invention provides a hydraulic actuator for operating an engine valve, which includes a control element for controlling the seating velocity of the valve. The present invention provides for free, unrestricted movement of the valve during opening, and an unrestricted return of the valve until the valve is within a predetermined distance of the valve seat. Once within this predetermined range, the return velocity of the engine valve is limited by the rate at which a fluid may escape through a flow restriction. The restriction is calibrated to provide the desired maximum valve seating velocity.

Abstract: An engine valve actuation system is disclosed, which is capable providing compression release engine braking in combination with exhaust gas recirculation while maintaining main exhaust and main intake valve events of constant magnitude during both positive power and engine braking. The system is also capable of providing a constant level of desired overlap between main exhaust and main intake valve events during both positive power and engine braking. The system may provide the foregoing functions by using first and second valve actuation subsystems to provide the full spectrum of exhaust valve motions. Both the first and second subsystems may receive an input motion from a valve train element. The first subsystem operates only when the engine braking system is enabled. The second subsystem operates both during positive power and during engine braking.

Abstract: An exhaust brake for an internal combustion engine is disclosed. The exhaust brake includes a main valve and a bypass valve for restricting the flow of exhaust gas. The main valve may be selectively closed, while the bypass valve is biased into a closed position with a selective biasing force. Closing the main valve may cause exhaust back pressure to build against the bypass valve until the biasing force is overcome. When the biasing force is surpassed by the exhaust back pressure, the bypass valve opens to relieve the back pressure. The bypass valve closes when back pressure falls below the biasing force. The biasing force may be varied to operate the exhaust brake at a maximum back pressure for a given engine speed and/or engine condition. A method of operating the exhaust brake is also disclosed.

Abstract: In an internal combustion engine braking system which may provide compression release braking and/or exhaust braking, methods and systems are disclosed of controlling the overlap between an exhaust gas recirculation event and an intake valve event to optimize engine braking at various engine operating speeds. Optimization may be achieved by selectively advancing and retarding the opening and closing of an exhaust valve for exhaust gas recirculation. The opening and closing of the exhaust valve may be carried out responsive to the monitored levels of such engine parameters as: exhaust manifold pressure, exhaust manifold temperature, cylinder pressure, and/or cylinder temperature. Various engine parameters may be monitored. Control of exhaust gas recirculation may be responsive thereto, such that a monitored parameter does not exceed a predetermined level.

Abstract: A variably timed internal combustion engine valve actuation system and method for opening valves in internal combustion engines. The system functions during both positive power and engine braking, to control the amount of "lost motion" between a valve and a means for opening the valve. In particular, the invention relates to a lost motion engine valve actuation system using a dedicated cam for effecting exhaust valve openings for compression release braking and exhaust gas recirculation ("EGR").

Abstract: An internal combustion engine has electrically controlled hydraulic linkages between engine cams and engine cylinder valves. If it is desired to skip a cam lobe or to modify the response of an engine cylinder valve to a cam lobe, hydraulic fluid is selectively released from the associated hydraulic linkage to permit lost motion between the cam and the engine cylinder valve. Electrically controlled hydraulic fluid valves are used to produce the selective release of hydraulic fluid from the hydraulic linkages. The mode of operation of the engine can be changed (e.g., from positive power mode to compression release engine braking mode or vice versa), or more subtle changes can be made to modify the timing and/or extent of engine cylinder valve openings to optimize engine performance for various engine or vehicle operating conditions (e.g., different engine or vehicle speeds). The valves can be controlled to produce an exhaust gas recirculation event during various operating modes of the engine.

Abstract: The present invention is directed to a start-up system for an engine valve actuation assembly. The start-up system may comprise a removal assembly for removing at least one of air and debris from the engine valve actuation assembly during an engine start up operation. The removal assembly may include a supply assembly for supplying fluid to the engine valve actuation assembly under high pressure to remove at least one of air and debris from the engine valve actuation assembly. The supply assembly may include a storage assembly for storing a supply of hydraulic fluid, and a fluid supply assembly for supplying fluid to the storage assembly. The fluid may be supplied under pressure from the storage assembly to the engine valve actuation assembly. Furthermore, the fluid may be supplied under an influence of gravity from the storage assembly to the engine valve actuation assembly.

Abstract: An exhaust restriction device for an internal combustion engine is disclosed. The exhaust restriction device includes a main valve and a bypass valve for restricting the flow of exhaust gas. The main valve is located in a main passage and may be selectively closed. The bypass valve is located in a bypass passage and is biased into a position closing a port connecting the main passage and the bypass passage. Closing the main valve may cause exhaust back pressure to build against the bypass valve and an actuator therefor until the biasing force is overcome. When the biasing force is surpassed by the exhaust back pressure, the bypass valve opens to relieve the back pressure. The bypass valve closes when back pressure falls below the biasing force. A method of operating the exhaust restriction device is also disclosed.

Abstract: An apparatus for limiting the travel of a slave piston in a slave piston cylinder in a compression release engine retarder is disclosed. The apparatus is connected to a hydraulic circuit and comprises an internal passageway in the slave piston head. The internal passageway comprises a vertical bore, a horizontal bore, and an annular channel which together provide a path for bleeding off the pressure on the top of the slave piston when the annular channel and an aperture in the slave piston cylinder are aligned. The bleeding of the hydraulic pressure on top of the slave piston clips the motion of the slave piston at a desired stroke. The apparatus includes a locking adjustable foot on the slave piston stem which provides a means to adjust the lash.

Abstract: The present invention is directed to a control system for controlling operation of an engine compression release brake for an engine. The control system includes a valve actuation assembly for actuating at least one valve during a predetermined engine operating condition. The control system also includes an energy supply assembly for supplying energy to operate the valve actuation assembly. The control system includes a control assembly for controlling the operation of valve actuation assembly.

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, pivoting bridge, an adjustable tappet, and a valve stem. The pivoting bridge may include a first end for contacting the adjustable tappet, a second end for contacting the valve stem and a pivot point between the first and second ends for contacting the valve train element. The amount of lost motion provided by the system may be selected by varying the position of the adjustable tappet relative to the pivoting bridge. Variation of the adjustable tappet position may be carried out by placing the adjustable tappet in hydraulic communication with a control trigger valve. Actuation of the trigger valve releases hydraulic fluid allowing for adjustment of the adjustable tappet position.