CA2053771A1 - Gefra adiabatic combustion engine - Google Patents

Abstract

"GEFRA" ADIABATIC COMBUSTION ENGINE

ABSTRACT

All internal combustion engines suffer from poor thermal efficiency.
This invention centres around novel design ideas which prevent thermal losses or recover heat for reuse in the combustion process.
In addition, frictional losses are kept very low by limiting the number of moving parts to the absolute minimum necessary to operate the engine.
Light weight parts and the absence of cooling media with all their mechanical components account for a much improved power to weight ratio.
The invention consists of a modified two cycle internal combustion engine of radial design.
Cylinders are arranged around a central crankshaft on which all the piston-connecting rod units share a common journal.
Dual purpose cylinders, with their respective piston-connecting rod units, are instrumental to recapture waste heat from the combustion process for recycling.
The modular design of the cylinder piston units has the advantage that a standard housing can be fitted with the number of cylinders to meet different power requirements.

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Description

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APPLICATION for LETTERS PA_ENT of INVFNTION
relating to the GEFRA Engine.

COUNTRIES
Austria, Canada, France, GermanY~ Great Britain, Ital~, Japan, United States of America.

Background of Invention:
This invention relates to recovery of thermal energy lost by engines of common design and to simplify the internal layout of the two cycle engine.
Thermal efficiency is estimated to be improved to 70 - 80 X
of available thermal energy of the fuel used.
Thermal losses are recovered mainly through inr,ovative design features which attempt to recapture most of the thermal energy ordinarily lost by matters of cooling, radiation, fuel stratification, frictiQn, poor combustion and exhaust losses.
In order to keep moving parts and thereFore sources of friction losses to the very minimum, an improved TWO CYCLE
system is used for tha engine of radial design, whereby three or more cylinder piston units are connected to the crankpin.

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Cylinders together with piston connscting rod uniks are arranged in a radial fashion around the central crankshaft.
All internal moving parts are contained within the circular housing.
In operation, the cylinders oscillate back and forth, activated by the movement of the one piece piston-connecting rod unit, in unison with the rotating crankshaft.
Power transfer through cylinder and piston-connecting rod is therefore always straight in line with the centre of the crankshaft pin. Pistons are designed for dual purpose, compression and expansion on top, intake and pre-compression below. The piston moving from ~DC to TDC, compresses air or a gas mixture on top, while filling the chamber below through an intake valve situated in the lower cylinder cover. Ignition at the top drives the piston down. Working pressure keeps the cylinder intake valve closed. Downward movement creates compression in the lower "pre-compression" chamber, presswre differential is closing the intake valve for the downstroke. Pressure in the sealed "pre-compression" chamber increases progressively during the downstroke. The pressure controlled lntake valve, located in the p-iston bottom, opens at the moment when the exhaust ports are cleared by the piston top, collapsing the pressure in the working chamber to below the pressure level in the lower chamber.

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Pre-compressed air or gas mixturs rushss into the working chamber, pushing exhaust gases out and filling and scavenging the worl<ing chamber.
As pressure increases on the up stroke, the piston valve is forced closed while at the same time increased suction opens the intake valve to the lower (pre-compression) chamber, pulling air mixture in for compressicn at the down stroke. The housing can be circular designed, with cylinder-piston units arranged at convenient angles. One housing can be fitted with one or more modular cylinder units for a wide range of power requirements. Exhaust gases are ~orced to deliver most of their thermal energy back into the useful cycle through a heat exchanger-turbocharger combination.
Outside air or gas mixture is preheated and comprassed into the crankcase housing, cooling the cylinder heads with a force proportional to the output o~ the turbocharger. At the beginning of the compression stroke, air or gas mixture in the engine housing, under low pressure from the turbocharger, fills the pre-compression chamber below the piston through the valve in the cylinder cover.
Simultaneously with the piston moving up compression takes place in the upper chamber to the poin~ where near TDC
ignition or injec~ion takes place for the following power stroke.

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Combustion pressure drives the piston down, keeping the piston valve closed to the point when the piston clears the exhaust ports. Pressure ~alls to near zero, there~ore openlng oF the piston valve takes place by virtue oF the higher pressure in the pre-compression chamber. Intake air or gas mixture rushes into the working chamber, pushing the waste gases out the exhaust ports and filling the upper 100 chamber with a fresh charge. With the piston moving up again, the compression and the pre-compression stroke is repeated. The inrushing air keeps the internal parts of the engine at a manageable temperature level. Circular firing order, or in the diesel mode - injection - , follows the direction of rotation of the crankshaft, providing a smooth vibration free operation.

DRAWINGS
1) Fig. 1.01. Timing Diagram 2) Fig. 2.01. Pressure Diagram 3) Fig. 3.01. System Layout 4) Fig. 4.01. Cylinder-Piston ~esign GEFRA Engine Inv. G.F.Fratzl Page -6- of eight

Claims

- CLAIM -SUMMARY of this INVENTION

It is the object of this exhibit to disclose the design, unique features, advantages, efficiency aspects, simplified modular construction, drastically reduced number of parts and the method of operation of this invention.

OBJECT of this Invention is:
a) To achieve thermal efficiency in an combustion engine, coupled with substantial fuel saving, multi fuel capacity, significant savings in weight, rugged compact design, fewer components requiring little precision machining.
b) Still another object of this Invention is to provide a system, where a number of cylinder units can be arranged within a standard housing to satisfy different power requirements. Cylinder units complete with a one piece piston-connecting rod, can be installed or removed with little effort, without affecting the overall function of the engine.
c) Still another object of this Invention is to have cylinder-piston units swing back and forth with the movement of the crankshaft, intensifying thermal exchange between parts directly exposed to combustion heat and in GEFRA Engine Inv. G.F.Frakzl Page -7- of eight turn passing thermal energy to the surrounding intake air mixture.
c) Still another object of this Invention is to make the crankshaft journal surface area large enough to assign each connecting rod bearing block one segment of the journal surface, whereby the mating surface could be a friction less bearing common to all piston units.
d) Still another object of this Invention is a double acting cylinder, whereby the space below the piston is sealed around the connecting rod to work as a pre-compression chamber. At the down/or power stroke, the air or gas mixture in the chamber below the piston is pre-compressed and at near BDC charged at high velocity through the piston intake valve into the combustion chamber on top of the piston.
e) Still another object of this invention is to use the exhaust gases to drive a turbine with hollow blades, whereby intake air passes through the hollow blades for the purpose of heat exchange and to load the engine housing to above atmospheric pressure.

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