Rotary machine and thermal cycle

Details Rotary machine and thermal cycle Rotary machine and thermal cycle

2002-09-30

2004-08-31

Denion, Thomas (Department: 3748)

Internal-combustion engines

Rotary

With compression, combustion, and expansion in a single...

C123S200000, C123S246000, C123S249000, C418S227000, C418S166000, C418S165000, C418S191000

Reexamination Certificate

active

06782866

ABSTRACT:

FIELD OF THE INVENTION
This invention relates generally to rotary machines and more specifically to internal and external rotary combustion engines, fluid compressors, vacuum pumps, and drive turbines for expandable gases or pressurized fluid and water.
BACKGROUND OF THE INVENTION
As the human race has evolved throughout the centuries, we, as a people, have used our minds to develop machines and tools to help us achieve higher evolutionary standards. Technological advances include the invention and discovery of the lever and the wheel in early times to more sophisticated communication and computational devices that we now enjoy in our daily lives. Nearly all aspects of technology, from the very rudimentary to the very complex, have made great advances that have made the daily lives of the people and animals on this planet much easier. However, there is one invention that has been with us for a long time that has received little technological advancement despite its extremely important use in our daily lives.
A typical four-cycle internal combustion reciprocating engine powers nearly all vehicles on the face of the planet. Likewise, the same engine is employed to power boats, generators, compressors, pumps, and machines of all type and design. However, despite its widespread use, the internal combustion, or Otto cycle, engine or, in certain instances, a diesel cycle engine, has received very little technological advancement. The changes made to the engine have left the basic thermal cycle of the engine untouched.
The reciprocating motion of common internal combustion engines, Otto and diesel cycle, is an inefficient method of producing rotary power. A typical four-cycle engine requires four reciprocating motions for each unit of power it delivers. Initially, the engine has an intake and compression stroke, followed by combustion, expansion, and exhaust strokes. The reciprocating motion of the four-cylinder engine requires four inertial changes of the rotating mass of the pistons, connecting rods, and assembly—each change in inertia yielding a power loss to the system. Likewise, each complete cycle of the internal combustion engine requires four inertial changes for the associated valves, springs, lifters, rocker arms, and push rods, yielding additional total loss of the engine.
The mechanical complexity of the standard internal combustion engine adds to the design's overall inefficiency. A single cylinder four-cycle engine requires many moving parts, including a piston, piston pin, connecting rod, crank shaft, a plurality of lifters, push rods, rocker arms, valves, valve springs, gears, a timing chain, and a fly wheel. Each one of these parts increases the probability of engine failure due to fatigue or wear. Likewise, this large number of parts increases the amount of inertial mass that must change four times per cycle, reducing power produced by the system. Each moving part is subject to frictional loss between each relative part, adding to power loss. Further, it is expensive to manufacture and maintain equipment requiring such a large number of moving parts.
A typical four-cycle engine is a low torque, high r.p.m. machine. Because the relatively short throw of the crank arm yields a very low tortional moment, the Otto cycle engine requires a higher r.p.m. to achieve higher power ratings. More specifically, both Otto and diesel cycle engines achieve their highest internal pressure at approximately the lowest tortional moment in the piston cycle, top dead center. Thus, the engine cycle does not mate the engine's greatest potential to do work—highest internal pressure—with the engine's best ability to exploit that potential or convert it to power. Further, the torque moment is not constant. Rather, the torque moment is at approximately zero at top dead center, reaches its highest value at mid-stroke, and returns to zero at bottom dead center. By design, the highest internal pressure occurs when the piston is at approximately full stroke or extension. Therefore, a majority of the initial force generated during combustion is transmitted axially down the piston and connecting rod and is not transferred to rotational power. Only subsequently, as the tortional moment enlarges, is a majority of the expansive force converted into rotational power. The resulting structural requirements limit piston assembly design, increasing mass and limiting material choice. Further, transmissions are necessary to amplify the relatively low torque generated by the reciprocating motion, thus adding weight, cost, complexity and additional power requirements to the overall system.
The compression, and thus heating, of the original unit volume of combustion products leads to further power loss. Gas expansion is dependent upon the temperature of the gas prior to ignition—with all other variables held constant, a gas with a cooler ignition temperature will expand more than the same gas at a hotter ignition temperature, given the space to do so. Therefore, the heating of the fuel/air mixture by compression prior to ignition reduces the amount of expansion, and thus work, attainable during the subsequent expansion stroke. Likewise, the reciprocating design limits the combustion product's ability to do useful work because the expansion volume is not equal to the compression volume-combustion heats the gas, thus increasing the expansion volume beyond the initial volume. Thus, relatively high-pressure combustion gases are exhausted without performing any useful work.
The overall design of Otto, diesel, and other rotary engines is limited by cross-leakage at high pressure. More specifically, cross leaking is internal pressure loss due to overflow from the high-pressure side to the low-pressure side of the system while the pistons move throughout their stroke. Leakage generally occurs around the piston and the cylinder walls, exhaust and inlet ports, and between the cylinder head and the block. The excessive number of seals and connecting parts in other internal combustion engines creates cross-leakage liability. Therefore, the operating internal pressure range of the engines is greatly reduced.
Yet another limitation of current rotary engine technology is the internal combustion design of the engines. More specifically, current rotary engines are operable only as internal combustion engines. The current designs fail to allow for use as external combustion or external detonation cycle engines. Thus, the current state of rotary engine technology requires a considerably larger volume for expansion of the gases than is required with an external aspects of this invention.
A further limitation of current engine technology is a lack of design diversity. The extent of diversity for typical internal engines is limited by a need to drive a common crankshaft from a plurality of reciprocating motions. The engine design has developed little from standard in-line and v-type engine configurations. Even other rotary engine designs are singular in their rotary component arrangements. Alternative piston arrangements, such as cross rotation, have not been explored. This limited design diversity prevents possible space-saving designs from being developed.
Another design limitation of the internal combustion engine is the singularity of its use. The internal combustion engine is operable only as an internal combustion engine. It is a power source converting chemical energy into mechanical energy, the mechanical energy being in the form of a rotating shaft. The internal combustion engine itself has no ability to function with detonation chambers other than the internal combustion chamber, such as, for example, a shaped charge or other detonation cycle device, some of which provide external combustion. Furthermore, the internal combustion engine itself is incapable of functioning as an air compressor, a vacuum pump, an external combustion engine, water pump, a drive turbine for expandable gas, or a drive turbine.
SUMMARY OF THE INVENTION
The present invention comprises a rotary machine capable of functioning as a

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