Accession Number : ADD018012

Title :   External Combustion Engine Having An Asymmetrical Cam and Method of Operation.

Descriptive Note : Patent, Filed 30 Nov 94, patented 12 Mar 96,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Duva, Anthony W

Report Date : 12 Mar 1996

Pagination or Media Count : 9

Abstract : An external combustion engine having an asymmetrical cam. The engine includes a combustion chamber for generating a high-pressure, energized gas from a monopropellant fuel and an even number of cylinders for sequentially receiving the energized gas through a rotary valve, the gas performing work on a piston disposed within each cylinder The pistons transfer energy to a drive shaft through a connection to the asymmetrically shaped cam. The cam is shaped having two identical halves, each half having a power and an exhaust stroke. The identical halves provide that opposing cylinders are in thermodynamic balance, thus reducing rocking vibrations and torque pulsations. Having opposing pistons within the same thermodynamic cycle allows piston stroke to be reduced while maintaining displacement comparable to an engine having individual cycle positions. The reduced stroke diminishes gas flow velocity thus reducing flow induced noise. The power and exhaust strokes within each identical half of the cam are asymmetrical in that the power stroke is of greater duration than the exhaust stroke. The shape and length of the power stroke is optimized for increased efficiency.

Descriptors :   *CAMS, *PATENTS, *EXTERNAL COMBUSTION ENGINES, VELOCITY, PISTONS, VIBRATION, THERMODYNAMICS, SHAPE, HIGH PRESSURE, ENERGY TRANSFER, GASES, REDUCTION, FUELS, FLOW RATE, ASYMMETRY, PULSES, CYLINDRICAL BODIES, BALANCE, OPERATION, COMBUSTION CHAMBERS, THERMODYNAMIC CYCLES, POWER, VALVES, FLOW NOISE, GENERATORS, ROTATION, TORQUE, GAS GENERATING SYSTEMS, GAS FLOW, DRIVE SHAFTS, MONOPROPELLANTS

Subject Categories : Reciprocating and Rotating Engines

Distribution Statement : APPROVED FOR PUBLIC RELEASE