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 engine braking assembly and method for producing a bleeder braking event in an engine having at least one engine valve, at least one engine cylinder, and intake and exhaust manifolds. The engine braking assembly comprises an engine housing, having a hydraulic circuit formed therein; a high-pressure fluid source adapted to store high-pressure fluid therein; a valve for controlling the flow of the high-pressure fluid, in communication with the high-pressure fluid source through the hydraulic circuit; a control device for selectively controlling the valve; and a valve actuation assembly in communication with the valve through the hydraulic circuit, wherein the valve actuation assembly receives the high-pressure fluid through the valve and wherein the hydraulic force created by the high-pressure fluid actuates and holds open the at least one engine valve to produce the bleeder braking event.

Abstract: The present invention is a valve opening mechanism which has been designed so as to be able to open an actuator pin (30), on which a stop (31) is provided that is through-mounted to slide freely facing in a vertical direction in relation to the top of a rocker arm (7) and which is restrained by the bottom of the rocker arm (7) tip at a specified uppermost position, and the engine valves (4), by pushing downward during the exhaust stroke of a rocker arm (7).

Abstract: The present invention is directed to an improved assembly for operating at least one exhaust valve and at least one intake valve in a cylinder in an engine. The assembly includes a rocker shaft, an intake rocker arm pivotally mounted on the rocker shaft for operating at least one intake valve of the engine cylinder, an exhaust rocker arm pivotally mounted on the rocker shaft for operating at least one exhaust valve of the engine cylinder. The improved assembly includes a lash adjusting assembly for adjusting a lash between at least one of the intake rocker arm and the at least one intake valve, and the exhaust rocker arm and the at least one exhaust valve. The improvement further includes a fluid supply assembly for supplying fluid to the lash adjusting assembly to operate the lash adjusting assembly. The improved assembly further includes a control assembly for controlling the operation of the supply assembly in response to predetermined engine operating conditions.

Abstract: The present invention relates generally to a system and method for actuating one or more valves in an internal combustion engine. In particular, the present invention relates to a system and method that may provide lost motion valve actuation of intake, exhaust, and auxiliary valves in an internal combustion engine.

Abstract: A method and rocker arm assembly for actuating an engine valve are disclosed. The rocker arm may include an integrated hydraulic circuit used to control a lost motion piston. A reset piston may be included in the rocker arm to selectively reset the position of the lost motion piston. A control piston may also be included in the rocker arm to selectively lock the reset piston into a reset position. The rocker arm assembly may be used to achieve compression-release or bleeder braking, main intake, main exhaust, brake gas recirculation, and/or exhaust gas recirculation valve events.

Abstract: The present invention relates to methods of improving engine braking of a reciprocating piston internal combustion engine by variable valve actuation. One embodiment of the present invention enables independent two-valve actuation for each cylinder, and engine braking horsepower can be optimized using two-valve braking at high engine speeds and one-valve braking at low speeds. Another embodiment of the present invention enables better a sequential valve actuation to reduce engine braking load and compliance. Another embodiment of the present invention enables better engine starting and warming up by controlling timing and lift of each valve.

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: The present invention is directed to a system and method for controlling an engine braking system having an engine with at least one intake and exhaust valve, intake and exhaust manifolds, a turbocharger connected to the intake and exhaust manifolds, and at least one pressure regulation valve. The method may comprise the steps of measuring a value of an engine parameter; adjusting the pressure of the exhaust manifold responsive to the measured engine parameter value; actuating the at least one exhaust valve; and adjusting a pressure gradient across the turbocharger.

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: The present invention provides a hydraulic actuator for operating an engine valve, which includes a means for controlling the seating velocity of the valve. The design allows for free, unrestricted movement of the actuator piston during opening of the engine valve, and an unrestricted return of the piston and valve until the valve is within a predetermined distance of the valve seat. Once within this predetermined range, the return velocity of the actuator piston and engine valve are limited by the rate at which a fluid may escape through a restriction. The restriction is calibrated to provide the desired maximum valve seating velocity. The invention also provides for automatic lash adjustment.

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: A system for controlling the seating of an engine valve is disclosed. The system is designed to bring a hydraulically actuated engine valve to a soft landing on its valve seat. The velocity of the engine valve is reduced as it approaches its seat by progressively throttling the escape of hydraulic fluid from a chamber. The chamber is pressurized as a result of the valve approaching its seat. Accordingly, as the valve approaches its seat, the pressure in the chamber increases, causing the force that opposes the closing motion of the engine valve to increase.

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 a system for operating at least one exhaust valve of an engine. The engine has at least two engine operating conditions. The system in accordance with the present invention includes an energy supply assembly for supplying energy to operate the at least one exhaust valve during one of the at least two engine operating conditions. The system may further include an energy transfer assembly for transferring the energy from the energy supply assembly to operate the at least one exhaust valve. A valve actuating assembly is also included for actuating the at least one exhaust valve in response to operation of the energy transfer assembly.

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: The present invention provides a hydraulic actuator for operating an engine valve, which includes a means for controlling the seating velocity of the valve. The design allows for free, unrestricted movement of the actuator piston during opening of the engine valve, and an unrestricted return of the piston and valve until the valve is within a predetermined distance of the valve seat. Once within this predetermined range, the return velocity of the actuator piston and engine valve are limited by the rate at which a fluid may escape through a restriction. The restriction is calibrated to provide the desired maximum valve seating velocity. The invention also provides for automatic lash adjustment.

Abstract: The present invention is directed to an actuator piston assembly for use in a rocker arm system. The actuator piston assembly is capable of actuating at least one engine valve during for example engine braking. The actuator piston assembly includes a piston body having a hollow interior, a screw assembly received within the hollow interior of the screw assembly, a biasing assembly for biasing the piston body with respect to the screw assembly, a cap assembly located within the hollow interior, wherein the biasing assembly interacts with the cap assembly and the screw assembly, and a securing assembly for movably securing the piston body to the screw assembly.

Abstract: The present invention is directed to an apparatus for operating at least one intake valve and at least one exhaust valve in an engine cylinder. The apparatus includes an exhaust valve operating assembly for operating the at least one exhaust valve of the engine cylinder, wherein the exhaust valve operating assembly is capable of producing an exhaust gas recirculation event. The apparatus also includes an intake valve operating assembly for operating the at least one intake valve of the engine cylinder. The apparatus further includes an exhaust modifying assembly for modifying the operation of the exhaust valve operating assembly during a predetermined engine operating condition and an intake modifying assembly for modifying the operation of the intake valve operating assembly during a predetermined engine operating condition.

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.