Abstract: A system for actuating one or more engine valves for positive power operation and engine braking operation is disclosed. In a preferred embodiment, an exhaust valve bridge and intake valve bridge each receive valve actuations from two sets of rocker arms. Each valve bridge includes a sliding pin for actuating a single engine valve and an outer plunger disposed in the center of the valve bridge to actuate two engine valves through the bridge. The outer plunger of each valve bridge may be selectively locked to its valve bridge to provide positive power valve actuation. During engine braking, application of hydraulic pressure to the outer plungers may cause the respective valve bridges and outer plungers to unlock so that all engine braking valve actuations are provided from a rocker arm acting on one engine valve through the sliding pin.

Abstract: A system for actuating one or more engine valves for positive power operation and engine braking operation is disclosed. In a preferred embodiment, an exhaust valve bridge and intake valve bridge each receive valve actuations from two sets of rocker arms. Each valve bridge includes a sliding pin for actuating a single engine valve and an outer plunger disposed in the center of the valve bridge to actuate two engine valves through the bridge. The outer plunger of each valve bridge may be selectively locked to its valve bridge to provide positive power valve actuation. During engine braking, application of hydraulic pressure to the outer plungers may cause the respective valve bridges and outer plungers to unlock so that all engine braking valve actuations are provided from a rocker arm acting on one engine valve through the sliding pin.

Abstract: Devices and related methods are disclosed that generally involve variable actuation of engine valves. In one embodiment, a valve train for a split-cycle internal combustion engine or an air hybrid split-cycle engine is provided that includes a cam phaser, a dwell cam, an adjustable mechanical element for performing a variable valve actuation function, and/or a valve seating control device. The devices and methods disclosed herein also have application in conventional internal combustion engines and can actuate inwardly-opening and/or outwardly-opening valves.

Abstract: Devices and related methods are disclosed that generally involve the selective deactivation of one or more engine valves. In one embodiment, a split-cycle internal combustion engine is provided in which a high-speed trigger valve is used to fill and drain a hydraulic tappet that forms part of a lost-motion system of an engine valve. A spool valve can be used to selectively disconnect the tappet from the trigger valve, thereby deactivating the associated engine valve (i.e., preventing the engine valve from opening). The devices and methods disclosed herein also have application in conventional internal combustion engines and can be used with inwardly-opening and/or outwardly-opening valves.

Abstract: A system for actuating one or more engine valves for positive power operation and engine braking operation is disclosed. In a preferred embodiment, an exhaust valve bridge and intake valve bridge each receive valve actuations from two sets of rocker arms. Each valve bridge includes a sliding pin for actuating a single engine valve and an outer plunger disposed in the center of the valve bridge to actuate two engine valves through the bridge. The outer plunger of each valve bridge may be selectively locked to its valve bridge to provide positive power valve actuation. During engine braking, application of hydraulic pressure to the outer plungers may cause the respective valve bridges and outer plungers to unlock so that all engine braking valve actuations are provided from a rocker arm acting on one engine valve through the sliding pin.

Abstract: A system for actuating an engine valve to decompress an engine cylinder for engine start up and/or engine braking is disclosed. The system may include a first member, such as an outer piston, disposed above an engine valve, which receives an inner piston extending into a bore provided in the first member. One or more springs may bias the inner piston into a predefined position in the first member. The inner piston may include a lower surface that directly, or through an intervening sliding pin, actuates an engine valve in response to the application of fluid pressure on the inner piston. The inner piston may be used to decompress an engine cylinder for engine start up and/or to provide engine braking.

Abstract: Devices and related methods are disclosed that generally involve variable actuation of engine valves. In one embodiment, a valve train for a split-cycle internal combustion engine or an air hybrid split-cycle engine is provided that includes a cam phaser, a dwell cam, an adjustable mechanical element for performing a variable valve actuation function, and/or a valve seating control device. The devices and methods disclosed herein also have application in conventional internal combustion engines and can actuate inwardly-opening and/or outwardly-opening valves.

Abstract: In controlling valve motions of an internal combustion engine, after determining that engine braking operation has been initiated, a deactivation mechanism disposed within a main valve train is activated thereby disabling conveyance of main valve events from a main valve motion source to a valve via the main valve train. Engine braking valve events are enabled for the valve, which may include two-stroke engine braking. Coupling mechanisms, including one-way coupling mechanisms, between adjacent rocker arms may be used in this manner.

Abstract: A system for actuating one or more engine valves for positive power operation and engine braking operation is disclosed. In a preferred embodiment, an exhaust valve bridge and intake valve bridge each receive valve actuations from two sets of rocker arms. Each valve bridge includes a sliding pin for actuating a single engine valve and an outer plunger disposed in the center of the valve bridge to actuate two engine valves through the bridge. The outer plunger of each valve bridge may be selectively locked to its valve bridge to provide positive power valve actuation. During engine braking, application of hydraulic pressure to the outer plungers may cause the respective valve bridges and outer plungers to unlock so that all engine braking valve actuations are provided from a rocker arm acting on one engine valve through the sliding pin.

Abstract: Devices and related methods are disclosed that generally involve variable actuation of engine valves. In one embodiment, a valve train for a split-cycle internal combustion engine or an air hybrid split-cycle engine is provided that includes a cam phaser, a dwell cam, an adjustable mechanical element for performing a variable valve actuation function, and/or a valve seating control device. The devices and methods disclosed herein also have application in conventional internal combustion engines and can actuate inwardly-opening and/or outwardly-opening valves.

Abstract: Devices and related methods are disclosed that generally involve the selective deactivation of one or more engine valves. In one embodiment, a split-cycle internal combustion engine is provided in which a high-speed trigger valve is used to fill and drain a hydraulic tappet that forms part of a lost-motion system of an engine valve. A spool valve can be used to selectively disconnect the tappet from the trigger valve, thereby deactivating the associated engine valve (i.e., preventing the engine valve from opening). The devices and methods disclosed herein also have application in conventional internal combustion engines and can be used with inwardly-opening and/or outwardly-opening valves.

Abstract: Devices and related methods are disclosed that generally involve the selective deactivation of one or more engine valves. In one embodiment, a split-cycle internal combustion engine is provided in which a high-speed trigger valve is used to fill and drain a hydraulic tappet that forms part of a lost-motion system of an engine valve. A spool valve can be used to selectively disconnect the tappet from the trigger valve, thereby deactivating the associated engine valve (i.e., preventing the engine valve from opening). The devices and methods disclosed herein also have application in conventional internal combustion engines and can be used with inwardly-opening and/or outwardly-opening valves.

Abstract: A system for actuating an engine valve to decompress an engine cylinder for engine start up and/or engine braking is disclosed. The system may include a first member, such as an outer piston, disposed above an engine valve, which receives an inner piston extending into a bore provided in the first member. One or more springs may bias the inner piston into a predefined position in the first member. The inner piston may include a lower surface that directly, or through an intervening sliding pin, actuates an engine valve in response to the application of fluid pressure on the inner piston. The inner piston may be used to decompress an engine cylinder for engine start up and/or to provide engine braking.

Abstract: Devices and related methods are disclosed that generally involve the selective deactivation of one or more engine valves. In one embodiment, a split-cycle internal combustion engine is provided in which a high-speed trigger valve is used to fill and drain a hydraulic tappet that forms part of a lost-motion system of an engine valve. A spool valve can be used to selectively disconnect the tappet from the trigger valve, thereby deactivating the associated engine valve (i.e., preventing the engine valve from opening). The devices and methods disclosed herein also have application in conventional internal combustion engines and can be used with inwardly-opening and/or outwardly-opening valves.

Abstract: Devices and related methods are disclosed that generally involve variable force valve springs for controlling the motion of an engine valve. The force exerted by the valve spring can be adjusted by altering the pressure at which a fluid is supplied to a fluid chamber thereof, by altering the volume of the fluid chamber, and/or by changing the aggregate surface area over which fluid pressure is coupled to the engine valve. Associated fluid control systems are also disclosed herein, as are various methods for adjusting the force of a valve spring based on a variety of engine parameters, such as engine speed, engine load, and/or a combination thereof.

Abstract: Devices and related methods are disclosed that generally involve variable actuation of engine valves. In one embodiment, a valve train for a split-cycle internal combustion engine or an air hybrid split-cycle engine is provided that includes a cam phaser, a dwell cam, an adjustable mechanical element for performing a variable valve actuation function, and/or a valve seating control device. The devices and methods disclosed herein also have application in conventional internal combustion engines and can actuate inwardly-opening and/or outwardly-opening valves.

Abstract: A system for actuating one or more engine valves for positive power operation and engine braking operation is disclosed. In a preferred embodiment, an exhaust valve bridge and intake valve bridge each receive valve actuations from two sets of rocker arms. Each valve bridge includes a sliding pin for actuating a single engine valve and an outer plunger disposed in the center of the valve bridge to actuate two engine valves through the bridge. The outer plunger of each valve bridge may be selectively locked to its valve bridge to provide positive power valve actuation. During engine braking, application of hydraulic pressure to the outer plungers may cause the respective valve bridges and outer plungers to unlock so that all engine braking valve actuations are provided from a rocker arm acting on one engine valve through the sliding pin.