North American Philips Corporation

Magnavox Government and Industrial Electronics Company

Other

USA As Represented by Secretary of the Navy

Engineering Research Associates, Inc.

Frederick L Erickson

William E Richeson

Stephen G Putman

Jeffrey L Erickson

Richeson, William E

Design Improvements are disclosed which enhance the migrating combustion chamber engine's ability to achieve improved performance, obtain higher durability and cost less to manufacture. These include strip seals between the combustion chamber member and orbiting piston which are adapted to respond to the pressure of combustion to increase contact pressure and improve retention of the gases in the combustion chambers as well as improved porting located in at least one power block sidewall and cooperating with the migrating combustion chamber to convey hot combustion gasses from a combustion chamber to a corresponding secondary expansion chamber. The combustion chamber member may be formed of two reciprocable piston portions and a pair of separate alloy steel connecting bars coupling the piston portions together. The connecting bars made of a low thermal conductivity material to remain hot and aid in fuel evaporation. A one piece counterweight hub provides all required counterweights. It attaches to the crankshaft by a first clamp which clamps the counterweight hub onto the crankshaft, and second clamp which pulls an inside bore of the hub axially tight against an end of the crankshaft. Improvements in exhaust porting, ignition location, manifold and combustion chamber member designs as well as unique power block housing wear strips and crankshaft counterbalancing techniques are also disclosed.

Migrating combustion chamber engine

Non-symmetrical port timing techniques in combination with the 90 degree phase difference between the pumping and combustion chamber of the two stroke migrating combustion chamber engine variant are disclosed as a special cycle of operation which allows a high degree of self supercharging and attendant performance advantages. Other embodiments include; protected fuel injection provisions, externally located induction rotor valves/counterweights to achieve better volumetric efficiency and complete dynamic balance and a technique to improve engine mechanism durability.

Self supercharged two stroked cycle and engine having migrating

A hydraulic actuator includes a pneumatic piston, a hydraulic piston, and an engine valve on a common shaft. The pneumatic piston is urged between first and second stable positions primarily by a double acting pneumatic spring, with high pressure hydraulic fluid connected to a first hydraulic chamber being used to cock the hydraulic piston in a first stable position (engine valve closed). Hydraulic fluid isolated in a second hydraulic chamber is used to latch the hydraulic piston in a second stable position (engine valve open). Transfer of hydraulic fluid between first and second chambers is effected by a carrier for two check valves, which carrier in a first position disables the second check valve to permit fluid to flow from the second chamber to the first chamber, whereupon the first check valve closes (cocking). In a second position the carrier disables the first check valve to permit fluid to flow from the first chamber to the second chamber, whereupon the second check valve closes (latching). The carrier may be controlled directly by an EM actuator, or by hydraulic fluid channeled from a pilot valve which is EM actuated.

Hydraulically powered actuator with pneumatic spring and hydraulic

A housing has a pilot bore with an electrically controlled pilot valve therein, an intermediate bore with an intermediate valve therein, and an engine bore with a main valve therein, each valve being reciprocable between first and second stable positions. When said pilot valve is switched to its first stable position, high pressure hydraulic fluid drives said intermediate valve to its first stable position and releases said engine valve from its second stable position, whereupon a double acting spring drives the engine valve toward its first stable position. High pressure hydraulic fluid completes this movement then holds the main valve in its first stable position against the force of the double acting spring. Switching the pilot valve to its second stable position effects movement of the other valves back to their second stable positions.

Pilot operated hydraulic valve actuator

A highly efficient all hydraulic poppet valve actuator utilizes fluid spring chambers at each end of travel to store energy. Fluid in a first spring chamber is compressed and the chamber cocked by supplemental hydraulic pressure which also seats a poppet valve. A first activation device cancels this pressure to allow transit of the poppet valve and re-cocking of the second spring chamber. Return activation is caused by cancelling a fluid latch to allow transit back to an initial position which recloses the poppet valve.

Resilient hydraulic actuator

Valve assembly includes a stem having a first section toward the cam and a second section toward the valve face, the first section having a larger diameter than the second section. A housing defines a closed chamber having a first bore which closely receives said first section and a coaxial second bore which closely receives the second section. As the cam rotates to lift the valve face from the valve seat, the first section acts as a piston which increases pressure of hydraulic fluid in the chamber to provide a spring force to return the valve.

Cam actuated valve assembly with hydraulic spring

A two-stroke-cycle spark ignited internal combustion engine operates with an exhaust valve that is controlled independently of crankshaft position and optimally for high power and low pollutant output in combination with a scavenging pump and fuel injector. The volume of combustible mixture is established at the point in the cycle when the exhaust valve is selectably closed with the piston traveling upwardly and decreasing the volume of the cylinder. Throttling losses are eliminated since the piston forces the scavenging air out of the cyclinder through the wide-open exhaust valve rather than the air being drawn into the cylinder against the reduced pressure caused by a conventional partially closed throttle plate. The volume of combustible air in the cylinder is determined by the point in the cycle at which the exhaust valve is closed and a correspondingly appropriate charge of fuel is thereafter injected into the cylinder.

Two-stroke-cycle engine with variable valve timing

A high efficient actuator used to operate an engine's poppet valves is disclosed. Pneumatic pressure is applied to an actuator piston which is locked in either a first or a second position by an interconnected fluid latch. Upon a timed command, the piston latch is released allowing the pre-pressurized piston to rapidly transit from whichever of its two positions it happens to be in to the other. The actuator is configured to compress the air on the advancing side of the piston as the energy of the expanding air is propelling the piston to its other position. The fluid latch is configured to prevent the main piston from reversing direction at the end of its travel, thus trapping all the compressed air to be used to help propel the actuator piston back to its original position. The actuator has a feature for supplying make up air on the opening portion of the cycle in order to compensate for blow down as well as other losses. The actuator also has a feature for increasing the pressure in the latching chamber during the return stroke to assure positive seating of the interconnected poppet valve.

Highly efficient pneumatically powered hydraulically latched actuator

A two position straight line motion actuator utilizes a double ended pneumatic spring to provide most of the energy required to transit back and forth between the two positions. The actuator is held in its initial position against the force of the pneumatic spring by hydraulic pressure applied to a latching piston. Transition from the initial or first position to the second position is initiated by opening a flow path around the latching piston to cancel the effects of the high pressure latch, thus allowing the air spring to power the actuator to its second position. As the actuator moves toward the second position, the second air spring dampens actuator motion converting the kinetic energy of the actuator moving portion into potential energy in the form of highly compressed air, thus cocking the second air spring. Return of the actuator is blocked by the fluid latch. Upon command, a valve opens the flow path around the latch, allowing the latch to release the actuator to return to its initial position. Supplemental hydraulic pressure is valved into the latching chamber during the latter part of travel of the moving portion of the actuator to overcome system friction and to assure that the actuator moves fully to its initial position. Both the speed and the distance traveled by the moving actuator portion may be controlled by pre-pressurization of the air chambers.

Pneumatic preloaded actuator

A two-stroke-cycle spark ignited internal combustion engine operates with an exhaust valve that is controlled independently of crankshaft position and optimally for high power and low pollutant output in combination with a scavenging pump and fuel injector. The volume of combustible mixture is established at the point in the cycle when the exhaust valve is selectably closed with the piston traveling upwardly and decreasing the volume of the cylinder. Throttling losses are eliminated since the piston forces the scavenging air out of the cylinder through the wide-open exhaust valve rather than the air being drawn into the cylinder against the reduced pressure caused by a conventional partially closed throttle plate. The volume of combustible air in the cylinder is determined by the point in the cycle at which the exhaust valve is closed and a correspondingly appropriate charge of fuel is thereafter injected into the cylinder.

An actuator which is used, for example, to operate an internal combustion engine poppet valve is configured to open the poppet valve by means of a high pressure hydraulic fluid. This fluid powers the actuator piston and, at the same time, compresses air to accomplish both damping of the piston and conversion of the kinetic energy of piston translation into potential (pneumatic) energy. The actuator is held or captured in the second or valve-open position by a hydraulic latch and when released, is returned by the stored pneumatic energy to its initial position. Damping of the returning actuator piston is accomplished by a separate adjustable pneumatic orifice arrangement to assure gentle seating of the poppet valve.

Hydraulically propelled phneumatically returned valve actuator

An electronically controllable pneumatically powered valve actuating mechanism for use in an internal combustion engine is disclosed. The engine is of the type having engine intake and exhaust valves with elongated valve stems. The actuator has a power piston reciprocable along an axis and adapted to be coupled to an engine valve and a pneumatic arrangement for moving the piston, thereby causing an engine valve to move in the direction of stem elongation between valve-open and valve-closed positions. The pneumatic arrangement includes a pair of control valves which are movable relative to the piston for selectively supplying high pressure air to the piston. Each control valve includes a thin walled portion having an inner cylindrical surface which slidingly engaging a portion of one of the enlarged diameter cylindrical portions of the piston. The inner cylindrical surface includes an end portion of enhanced strength and reduced inner diameter which is too small to receive the enlarged diameter cylindrical portion of the piston. The piston includes enlarged diameter cylindrical portions which cooperate with the motion of the corresponding control valve to stop the supply of high pressure air to the piston. A pneumatic damping arrangement imparts a first decelerating force to the piston when the engine valve reaches a first separation from one of said valve-open and valve-closed positions to begin reducing engine valve velocity as the engine valve approaches said one position, and imparts a second lesser decelerating force to the piston when the engine valve reaches a second lesser separation from that one position. A resilient member cooperates with and is deformed by the air control valve to prevent the application of piston moving air pressure to the piston when the air control valve is in the closed position, and included is an arrangement for adjustably selecting the amount of deformation of the resilient member when the air valve is in the closed position. An initializer to force the piston to one of its extreme positions upon start up, a pressure regulator, and an arrangement for minimizing surface tension induced valve sticking problems are also disclosed.

Pneumatically powered valve actuator

An electronically controlled actuator which compresses a fluid thereby storing potential energy as it transitions from a first to a second position is disclosed. The compressed fluid exerts a high force on the actuator and the potential energy is recovered in returning the actuator to the first position. A latching arrangement automatically locks the actuator shaft as it reaches the second position. The latching arrangement is selectively unlocked at the prescribed time to allow the stored potential energy to return the actuator to the first position.

Actuator with energy recovery return

An electronically controllable pneumatically powered valve actuating mechanism for use in an internal combustion engine is disclosed. The engine is of the type having engine intake and exhaust valves with elongated valve stems. The actuator has a power piston reciprocable along an axis and adapted to be coupled to an engine valve and a pneumatic arrangement for moving the piston. A pneumatic damping arrangement imparts a first decelerating force to the piston when the engine valve reaches a first separation from one of said valve-open and valve-closed positions to begin reducing engine valve velocity as the engine valve approaches said one position, and imparts a second lesser decelerating force to the piston when the engine valve reaches a second lesser separation from that one position. A resilient member cooperates with and is deformed by the air control valve to prevent the application of piston moving air pressure to the piston when the air control valve is in the closed position, and included is an arrangement for adjustably selecting the amount of deformation of the resilient member when the air valve is in the closed position. An initializer to force the piston to one of its extreme positions upon start up, a pressure regulator, and an arrangement for minimizing surface tension induced valve sticking problems are also disclosed.

A pneumatically powered valve actuator is disclosed including a valve actuator housing, a main piston reciprocable within the housing along an axis and a pair of auxiliary pistons fixed to and movable with the main piston. The main piston has a pair of oppositely facing primary working surfaces. A pair of air control valves reciprocable along said axis relative to both the housing and the main piston between open and closed positions control air flow from a pressurized source causing the main piston and the pair of auxiliary pistons to move. Each auxiliary piston forms, in conjunction with a surface of the corresponding air control valve, a variable volume annular chamber. The variable volume chamber function during the early portion of piston movement to apply a reclosing force to the air control valve and during a latter portion of the piston movement to vent air compressed by the piston during damping. This venting of the residual air is in an axial rather than a radial direction.

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Fort Wayne, IN, United States of America

Frederick L Erickson