Britalus Rotary Engine

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The Britalus rotary engine was invented in 1982 by Kenneth W. Porter, P.E., M.S.A.E, of King County, Washington.

It operates on a modified Brayton thermodynamic cycle, but with continuous pulsed combustion, similar to that of a gas turbine. It can burn most commonly-available hydrocarbon fuels, and features the high compression ratio (14:1) typical of a Diesel cycle.

Most automotive engines are of the four-cycle internal combustion type, using pistons within cylinders, and operating on principles first outlined by Sadi Carnot.

The Carnot cycle consists of induction of an air and fuel mixture, compression of this charge, ignition and burning of the mixture, followed by expansion of the combustion products and expulsion of the spent gases to the atmosphere.This ideal cycle is unattainable in practice, but formed the basis for most real engine cycles typified later by Brayton, Otto and Diesel

Many of the early Otto aircraft engines were classed as rotary engines, meaning that the cylinder block, carrying multiple pistons and cylinders rotated around a stationary crankshaft fixed to the aircraft frame. An aerodynamic propellor was attached to the rotating cylinder block which was usually air-cooled by fins machined on each surface exposed to the airstream.

The vast majority of internal combustion engines used in vehicles are of the in-line cylinder variety where the cylinders are stationary and only the crankshaft rotates, driven by the reciprocating pistons and their connecting rods. It is very difficult to avoid or minimize the out-of-balance forces and the resulting vibrations caused by this.

The main feature of the Britalus engine is an enclosed barrel-shaped cylinder block carrying compressor and expander pistons and rotating within a compact three-lobed stationary housing. The pistons carry rollers that follow an internal cam, causing the reciprocal motion of the pistons for compression and expansion. The rotor is statically and dynamically balanced and thereby operates with minimal vibration. A sleeve pinion gear on the rear of the rotor connects to a layshaft spur gear and provides the output shaft drive to the connected load.

Another distinguishing feature is the stationary slotted sleeve valve enclosing the single combustion chamber, and its co-axial slotted sleeve carried by the rotating cylinder barrel. This feature enables the charging air to enter the combustion chamber and allows evacuation later of the products of combustion to the expander cylinders and pistons.