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: For controlling motion of a movable part, a device comprises a first chamber and a second chamber in fluid communication with each other via a variable orifice that is responsive to pressure within the first chamber. Movement of the movable part is thereby at least partially controlled by flow of a fluid from the first chamber to the second chamber via the variable orifice. An increase in pressure in the first chamber may cause an increase in orifice area, whereas a decrease in pressure may cause a decrease in the orifice area. Pressure-dependent elements that change geometries and/or the pressure-based opening/closing of one or more bypass channels may be used for this purpose. Where bypass channels are used, a valve may be opened/closed based on an operating parameter of a system in which the movable part is a component. Such a system may comprise an internal combustion engine.

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: For controlling motion of a movable part, a device comprises a first chamber and a second chamber in fluid communication with each other via a variable orifice that is responsive to pressure within the first chamber. Movement of the movable part is thereby at least partially controlled by flow of a fluid from the first chamber to the second chamber via the variable orifice. An increase in pressure in the first chamber may cause an increase in orifice area, whereas a decrease in pressure may cause a decrease in the orifice area. Pressure-dependent elements that change geometries and/or the pressure-based opening/closing of one or more bypass channels may be used for this purpose. Where bypass channels are used, a valve may be opened/closed based on an operating parameter of a system in which the movable part is a component. Such a system may comprise an internal combustion engine.

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 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: 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: 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 actuating an engine valve with a cam having a dwell section. These devices and methods have application in split-cycle engines, air hybrid engines, conventional engines, and/or various combinations thereof. Both inwardly- and outwardly-opening valves can be actuated with the devices and methods disclosed herein. Additional valve train elements are disclosed, including rockers, lost-motion systems, and valve seating control devices.

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: 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 having a bore formed therein; an outer piston slidably disposed in the bore, the outer piston having an orifice formed therein; a catch piston slidably disposed in the outer piston; and an cone-shaped extension extending from the inner piston, wherein the cone-shaped extension is adapted to provide a variable flow area through the outer piston orifice to provide improved engine valve seating.