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License Offer -
Information on a new single-stroke engine or radial pulse turbine
To do or not to do something may be a serious, often even national decision.
Because of the ecology being on the brink of disaster worldwide owing to the generation of energy
and traffic, it would be irrepsonsible to further withhold an invention like the single-stroke engine.
This development could be an economic impetus to any national economiy, no matter where it is started.
The offer of an alternative engine concept for the new century sounds bold. It is to be hoped that the
concept of the single-stroke engine will set the development of new engines in train.
The success of this new and extraordinary innvotion will certainly fall to the first enterprise to try out
the prototype of the single-stroke engine.
Preliminary work and testing of this engine concept has been made so that there is nothing to stop
this new development.
Dear Sirs, this offer "still" gives you the opportunity to secure priorities regarding the single-stroke
engine. If you have any patent-related questions or consider any contractual arrangements, please
contact my patent attorneys:
OLBRICHT & BUCHHOLD Am Weinberg 15
DIPLOM PHYSIKER STAATL. GEPR. ÜBERSETZER D - 35096 Niederweimar
EUROPEAN PATENT ATTORNEY
Phone: 49-6421-7 86 27
Fax: 49-6421-71 53
If you are interested, I shall be pleased to send you more detailed information or answer your questions, if possible in writing because of the complexity of this engine.
Point to the changed edition (1)
On these CD a combustion engine is presented, which has to the goal, to improve the efficiency. From the patent writing is not this standard clear and reaching recognizable.
The improvement of the capacities does not lead, like at the Otto carburetor engine for the sinking of the efficiency. The idea have preceded pilot tests, which important new knowledge have yielded, them in addition to the patent writing on these CD are recorded.
The very bad efficiency of the automobile motors is known in expert circles, and is accepted as irrevocably. Has one given up ?.
Around this hopelessness to counteract, may multiplied these CD, at engineers and other interested person at home and abroad gratuitously are transmitted.
It is to be expelled however forbids the pamphlet or the CD, commercial without consent of the inventor. The transmission these CD absolutely forbids, if changes of text and drawing were undertaken without knowledge of the inventor. Against it is assumed constructive criticism and each further inspiration, welcome and becomes gladly and gratefully.
Them in the examples used designations and names are invented freely, as far as other not indicate. similarities with actual other inventions and name or data are by sheer good fortune.
To trick - and circle piston power machines exist countless protection rights. The responsibility for the regard of all counting copyrights lies alone with the user of the pamphlet or these CD. 14 Without explicit written permission of the inventor Walter Müller 35088 Battenberg Akazienstraße 11, may be published no part these manuscript over press television or Internet.17 It is possible, that the inventor owns Walter Müller further rights in announced and also at unannounced ideas, them on the specialized content in these CD - refer. The providing of these standards does not authorize, a claim from it the crown.
Copyrights on other intellectual property, is conceded explicitly in the written license contracts by the inventor and/or his patent attorneys.
Automatic Translation (1) (2) (3) (4)
An engine for the new century . . .
An engine for the new century - that sounds very promising. Such an engine would have to be a better automotive drive than the conventional four-stroke engine in every respect. This would be the only way towards an ecologically cleaner new automotive century. But the acceptance will only be guaranteed if the new engine can be manufactured more compact, more easily, better serviceable and above all more cheaply than all automotive drives that have existed so far. The engine has to be adaptable to all types of applications. It is most important that it has a considerably improved efficiency, i.e. in comparison with the conventional engine the fuel consumption would have to be reduced at least by half with the same performance. A new engine has to be future-oriented: pending ecological problems, especially the worldwide CO2 emission, can only be solved by a new principle of energy saving that will have to be a bench-mark for all further developments.
On April 16, 1997 the inventor Walter Müller was granted the European patent No. 0602272 for an engine that meets the aforementioned requirements of an alternative engine: it is the single-stroke engine (a rotary-piston engine).
This new single-stroke engine is worldwide the first combustion engine that is not cooled like conventional engines but can be operated completely heat-insulated. This is achieved by means of the design using modern technical ceramics.
After more than a century, the operating principle of the internal combustion engine has not changed: it seems to be an unassailable taboo for the automotive industry. It's time to do some rethinking.
The low thermal losses of the single-stroke engine improve combustion and reduce exhaust gases. Thermal losses are between only 7% and 15%. This illustrates the incredibly high efficiency and the big difference in efficiency with regard to conventional engines.
Attainable efficiency with the single-stroke engine (at 10% load !)
made of heat- resistan made of tech.
steel ceramics *
Exhaust gas 15 % 13 %
Cooling water 15 % 7% (if necessary)
Radiation 5% 3%
Mechanical losses 2% 2%
Efficiency 63% 75% (up to 80%)
*Approx. 500°C operating temp. on surfaces of cylinder and rotary piston made of ceramics.
The compression chamber is operated cold - whereas the working chamber is operated hot. Therefore the working chamber should be made of technical high-performance ceramics that can be operated at approx. 500°C surface red heat (or even higher).
Conventional engines are still literal "dirt catapults" - they have only negligibly been improved. The new single-stroke engine claims to cut the fuel consumption by half with the performance remaining unchanged. This inevitably will call sceptics onto the scene. On the other hand, nobody has ever asked why high performance and high efficiency do not add up with the internal combustion engine. Why is the performance of the conventional lifting-piston engine almost indefinitely high and the efficiency low? And vice versa: if the efficiency is high, why is the performance unacceptably low? All attempts made so far to change this have only ended in justifying the poor combustion of the the four-stroke engine. Until today the poor efficiency seems to have been inevitable. This fact can be hushed up or even excused: for example, the efficiency of a formula 1 racing car having an engine power output of 200 kW and a correspondingly high speed of rotation is just 5%. To put it more clearly: 5 litres out of 100 are used for driving - and 95 litres are exhausted, wasted.
This is proved by the latest test values of an engine development institute:
Engine Nominal Max. Usable efficiency
power output efficiency 1 at 10% load 2
Int. comb. engine 65 KW 32 % 17 %
Diesel engine 50 KW 38 % 25 %
Turbine 150 KW 36 % 15 %
Formula 1 200 KW 25 % 5 %
1 Result from rpm and torque in proportion to nominal power output
2 Rpm and torque reduced by load
BASIC CONSTRUCTION OF THE SINGLE-STROKE ENGINE
(1) Working chamber, (2) compressor, (3) sealing rolls, (4) injection nozzles, (5) valve discs, (6) check valve, (7) intermediate reservoir, (8) charging ports, (9) induction port, (10) exhaust port, (11) rotary-piston hub, (12) ignition or glow plugs, (Z) synchronous gears, (A - B) blade rotor (work), (C - D) blade rotor (compression). Please wait !
The frame shows the single-stroke cycle of operations. Please note that all functions listed in the frame take place simultaneously and are also finished within half a rotation. Compression and work take place synchonously. The compression process ends approx. 30° before the turning point - at the same time the charging process starts approx. 30° behind the turning point from the intermediate reservoir and ends 75° behind the turning point. The charging pressure is effective from both sides, the mixture columns meet at supersonic speed, explode immediately (also diesel-air mixture) - the working stroke is approx. 135° until the exhaust stroke. With this technique a costly and complicated injection and ignition control can be saved.
Fresh air from right + left ---------sucked in 1 + fuel injected
Mixture from right + left -------- compressed + stored intermediately
WORKING CHAMBER (hot)
Mixture shot in (charged) ------simultaneously from left and right Ignition left and right --------------- valve closed 4 left + righ
Power stroke2 left and right3 --------exhaust stroke left + right
1 Induction volume is 50% to 100% higher than working chamber volume (stroke volume)
2 Explosion + expansion, 3 means symmetrical piston stroke 4 0.0008 s ignition lag___________________________________________________________________________________
Comparison of maximum pressures and temperatures:
Four-stroke engine 2 shaft rotations 1 stroke
induction compression combustion exhaust
Gas temperature 120°C --- 300 - 600°C 2000° -3000°C 1300° - 1600°C
Gas pressure 0.9 bar 8 - 15 bar 30 - 50 bar 1 - 5 bar
Fuel consumption 250 - 350g/kWh (max. attainable 205 g/kWh)
Fuel dosing = fuel is dosed to air
Efficiency at 10% load 25% - 14% ( with formula1only 5%)
Two-stroke engine 1 shaft rotation 1 stroke
induction overflow compression combustion exhaust
Gas temperature 80 °C 120 °C 200° -400°C 2000° - 2800°C 500° - 1200°C
Gas pressure 0.9 bar 1bar 5 - 8bar 15 - 30 bar 1 - 3bar
Fuel consumption 400 - 600 g/kWh
Efficiency at 10% load 14% - 9 % (racing car engines 2 - 3%)
Fuel dosing = fuel is dosed to air
Single-stroke engine 1 shaft rotation 4 strokes (or 8 strokes possible)
suction compression transition explosion exhaust
in intermed. res. into cylinder + expansion
Gas temperature 20 °C 90°-150°C 100° - 120°C 1800° -2200°C approx.300°C4
Gas pressure 0.9 bar from 3 - 6 bar1 2 - 5 bar 3 15 - 20 bar 2 1 - 2 bar
1 in intermed. res., 2 working pressure before expansion, 3 cylinder charging,
4 depending on expansion possibility
Fuel consumption 120 -150 g/kWh Injection fuel quantity 0,0108g of diesel oil
Fuel dosing = air is dosed to fuel
Efficiency at 10% load 65% (with 500°C hot chamber 75% up to over 80%)
The scepticism about the single-stroke engine results from the fact that the gas exchange is still unknown. There is no gas exchange in the usual sense, therefore the engine is neither a four-stroke nor a two-stroke engine - and no gas turbine eithr. Thus it becomes obvious that it is difficult to explain such a future-oriented idea.
Si7 Please wait ! The one - stroke cycles- process in 10 pictures
Compressor > Work rotor < Compressorbild
nozzles ignition nozzles
Picture1 Basic Position
Change point compression (beginning) beginning of the power fuels injection
Please wait !
Compression and suck in - beginning
load channels and setback valves stand firm,
(are as circles hint at).
Please wait !
Compression and suck in + power fuels injection
In the between reservoir
Si9 Please wait !
Compressios half + suck in + power fuel injection
Nopower fuels losses possibly
Position compressors (load point in time) and ignition point in time the work pistons Picture 5 und picture 6
Please wait !
Compressions end - suck in end
Position to thet Load point in time and Ignition point in time
Position compressors (load point in time) and ignition point in time the work pistons
Si 10 Please wait !
Position work pistons to that Load point in time
The Ignition delay extend to the closing
The work pistons has at closet valve
After the explosion,
the first half expansion distance run trough
Please wait !
Work expansion end and exhaust end,
the second third of the expansion distance is run through
(Them load openings circles bevor the turn pistons run with).
Exhaust begining and aut push
Please wait !
Change - point
New beginning for load.and work
C1 = basic position displaced by 25° as against A1
C2 = intake - compression after 30° + start of injection
C3 = intake - compression + end of mixture formation after 120°
+ 30° until turning point
W1 = initial work position
W2 = start of charging at 2 - 6 bar from intermediate reservoir from 25°
W3 = end of charging + iginition after 35°
W4 = valve closed, explosion after 15° ignition lag
W5 = work - expansion until end of stroke at 60°
W6 = exhaust at 45°
Cycle during half a rotation of compressor and explosion chamber
and reference to by-pass for dosing of fresh air to fuel
The by-pass with throttle valve adjusts the fresh air to the quantity of fuel because up to the double quantity of fresh air can be drawn (at least 50% more).
The by-pass relieves the compression when no high performance is necessary, e.g. when driving in the city.
Because of this arrangement a sealing problem similar to the Wankel engine or a high compressor efficiency is no longer relevant.
Recommendation tu the
Prototype Works view
Specific features of the single-stroke engine:
· No dead centers, but turning points: no flywheel - no unbalance, symmetrical moments of forces: 4, or 6,- 8,-16, -18, - up to 24 strokes per revolution, depending on arrangement and number of blades of rotary piston.
· Explosion combustion with expansion and without afterburning.
· No sealing-strip problems: self-sealing velocities of flow are produced in the gaps (fits) (with 32000 strokes/min the sealing problem is far from being comparable with the sealing problems of the Wankel engine).
· Circumferential speed of rotary pistons approx. 6 - 8m/s - the speed of rotation is adapted accordingly.
· Speed optimally 1500 - 2000 rpm, max.3000 rpm, also an acceptable circumferential speed for ceramic rotary pistons.
· Sleeve bearings, synchronous gearing consisting of herringbone gears. No flywheel. Three engine shafts preferably cooled by the fuel.
· The single-stroke operations cannot be described as gas exchange because they take place uninfluenced by each other. Cold compression - hot explosion.
· The ignition point is retarded with the mixture columns colliding at supersonic speed at 5 bar pressure. By means of glow or spark plugs (approx. 15° spark lag) this igni- tion process is also safe for diesel oil mixture with a ten times lower compression.
· The double use of the segment cylinders doubles the usable stroke volume of the engine without increasing the engine. For example, 2x200cm3 become 800 cm3 of useful engine stroke volume. Fuel consumption: 120 - 150 g/kWh.
· The stroke ratio of a Langhuber piston engine having 16 cm2 piston surface =
45 mm diameter ist approx. 1.1:1 whereas the stroke ratio of the single-stroke engine having 16 cm2 piston surface with segment stroke is approx. 1.4 :1. Depending on fuel and explosion behaviour, this stroke ratio can be increased by increasing the radius of turn of the rotary piston. Power per unit of displacement: 225 KW/l. (This value is no typing error since the cylinder is used double!)
· If the segment cylinder Is bigger and the charge is smaller, the expansion will be more effective because of the increased stroke ratio and the efficiency will be considerably improved.
· The exhaust gas acceleration during the exhaust stroke will increase the following stroke because of the suction, but there is no scavenging effect as with the two-stroke process!
· The 1-stroke charging process charges, for example, 4x13 cm³ of mixture at a pressure of 5 bar in 0,006s.
Comparatively, the 4-stroke process has to draw in or charge atmospherically in 0,01s a 20 times bigger mixture volume with the same performance.
· No increased NOx because the reaction time is too short. The supersonic turbulence during charging assists the explosion in the sense of rotation without the well-known disadvantages of knocking. The explosion temperatures are advantageously above the ignition temperatures of CH and CO.
· Cylinder greasing: The single-stroke combustion chamber functions without cylinder greasing (non-contact movement).
· The combustion residues are used as self-renewing seal and catalytic support of the explosion. Glowing pockets assist the explosion.
· The ceramic working chamber can also be operated with externally compressed and stored air because no compression takes place in the working cylinder. See also remark on energy storing by the single-stroke engine.
· Wear of friction bearings and synchronous gears is the measure of the engine wear. The changing sealing gap is automatically sealed continuously by the unavoidable combustion residues. Excess material is continuously abraded at the narrows of the rotary body owing to the different peripheral speeds and blown out.
· The cold compression chamber is used for mechanical fuel preparation and is greased by the injected fuel without addition of a lubricant. The fuel balance is obtained after a few rotations.
· The drawing volume of the air for combustion is at least 50% bigger than the volume of the working cylinder (which corresponds to one charge!) The air is proportioned to the fuel stoichiometrically dosed via the by-pass.
Thus slip losses because of non-existant sealing strips are compensated.
· During acceleration the necessary greater quantity of fresh air is admitted to the fuel by closing the by-pass at the compressor. Consequently the amount of exhaust gas is not increased even with enrichment of fuel.
· The combustion quantities per stroke (0,0108g) are very small. Therefore the exhaust gas temperature falls far below the cylinder temperature though the combustion chamber is 500 °C hot.
· Engine cooling at 75% efficiency is restricted to moderate cooling via the three engine shafts.
Apart from these particularities the interaction between speed, compression and charge has a positive effect on the torque.
High compression - small combustion portions (low torque)
Low compression - big combustion portions (high torque)
High speed - small combustion portions (low torque)
Low speed - bigl combustion portions (high torque)*
*Therefore the loss of performance is very small in both cases, even with low speed, and the efficiency is constantly good.
This elasticity requires a simple, possibly only two-stage transmission.
In summary it may be said that the single-stroke engine can be modified in many ways. There is a wide and presently unimaginable range of applications.
· Diesel drive for CAR TRUCK BUS and TRAIN
· Heavy-oil drive for POWER PLANTS and SHIPS through
high-performance three-, four- or six-bladed single-stroke engines
· An alternative for the GAS TURBINE -- because high efficiency is also achieved with a slow-running engine.
· GENERATION OF CURRENT from NATURAL GAS primary energy or economical use of expensive secondary energy, e.g. hydrogen.
· ECOLOGIC DRIVES with bio-oil, biogas, wood gas.
· Application as FAST-RUNNING STIRLING ENGINE for use of external heat sources, e.g. geothermal energy etc
· BUILDING HEATING TECHNOLOGY without heat-transferring agent, with increased efficencies by means of a single-stroke current generator instead of a gas or oil burner. Floor heating. No heat losses in the pipes, no water damage.
· ENERGY STORAGE by means of external air charge compression. The single-stroke engine made of solid ceramics functions without compressor. The
· compressor performance saved is the energy storage performance that is recovered as required via a single-stroke current generator without necessity of compression by the engine.
· Decentralized SMALL POWER STATIONS for saving current transfer losses and achieving higher safety against failures.
· Suitable as economic TURBOPROP DRIVE etc.
During the last few years there have been many publications on the subject of "Man and Automobile". Comments are not very encouraging, but the authors agree in one respect: Locomotion by car and the resulting pollution of the air have become so natural that nothing has changed in spite of all criticism and protest. Essential changes in the new century cannot be seen, except that the power of engines will continue to increase and catalysts and soot filters will be attached to the engine.
The difference between the single-stroke gas exchange and the four-stroke and two-stroke gas exchange is that the first half rotation of the single-stroke engine generates two power strokes, the second half rotatation generates also two power strokes, and so do the third and fourth half rotations. In the case of internal combustion piston engines, it took more than one hundred years until something was done against these "poisoners and sooters". Looking back one can say that each so-called innovation dealt rather with the fuel than with the actual engine design. Then hope was based on the electric and electronic equipment, but little atten- tion has been paid so far to the actual cause of the very bad efficiency.
These omissions could now be made up for by the single-stroke engine. Though the single-stroke engine draws in, compresses, explodes and exhausts as well, the way is different owing to the separation between compression and work.
The function of the single-stroke engine is between the piston engine and the gas turbine (radial pulse turbine). In this case, the complete power acts only on the rotor. It is always a complete and precise cycle of power transmission that
takes place 8000 to 16000 times within a minute. Therefore the very good efficiency is maintained even at low speed with this single-stroke function.
For the time being, the four-stroke internal combustion engine is the absolute vehicle engine without competition. Therefore one cannot avoid to go back to the roots of engine development when presenting the single-stroke engine in order to make a difference between the gas exchange processes already known and the single-stroke gas exchange and make visible the disadvantages of the four-stroke combustion.
In this case, going back to the Lenoir engine (1860) does not mean to be hopelessly behind the times, because especially the later development of Nikolaus Otto, the atmospheric gas engine (1890) that was prompted by the Lenoir engine, shows how the efficiency can be improved after a real explosion by an unrestricted expansion possibility. It is the basic idea of the single-stroke engine to recall to our mind the forgotten expansion possibility without afterburning and use it as Otto did. Under this point of view, these old paths of development are becoming very interesting again.
Since then the performance has been the only interesting aspect of all newly developed engines. However the input used for achieving this performance has only been of marginal interest until today. The proof: Until today, one has been afraid of judging even up-to-date combustion engines by their efficiency.
For example, the development of the full-steam engine into the economical expansion steam engine was of great importance. At that time, the efficiency of steam engines could be essentially improved. But it was not possible to transfer this type of expansion to the four-stroke internal combustion engine.
Remember: With the expansion steam engine only approx. 1/5 of the piston path is charged with hot steam that expands during 4/5 of the piston path before it is exhausted. In comparison, the modern four-stroke automobile engine still functions according to the ancient method of the full-steam engine, i.e. without
expansion. The flame front burns right into the exhaust, pushing the unburnt mixture ahead before it is exhausted. By
means of a turbosupercharger one tries to recover lost energy.
It is to be expected that without genuine expansion precious energy will continue to be wasted as heat.
One is obliged to go back into the historical development of engines if one wishes to recognize that there is indeed a possibility to apply genuine expansion without afterburning also to combustion engines. This realization will help to establish the intellectual connection with the single-stroke function.
Maybe Nikolaus Otto showed us, though unconsciously at that time, the road to improvement of efficiency. Some details about this theory:
In 1860, Lenoir converted the principle of the steam engine into a combustion power engine. His engine was driven by the explosion of illuminating gas and was very rough and loud. The engine consumed approx. 4 m3 of illuminating gas per kW corresponding to a consumption of 8.8 m3/h and yielded max. 2.2 kW .
Otto wanted to eliminate these disadvantages which he managed in 1890 by means of the atmospheric gas machine. In this machine a piston with practically unlimited stroke was catapulted upward. Already then a genuine explosion of small amounts of mixture (in straight stroke direction) took place without preceding compression so that the engine could not be damaged. After the explosion the desired expansion of hot explosion gases (without afterburning) took place, which moved the piston into its final position. The emphasis has to be placed on "without afterburning". This is very important because the process described as expansion at the beginning of the four-stroke combustion was a braked, relatively slow burning-through of a flame front right into the exhaust.
Otto's atmospheric engine did not perform the actual work by explosion, but by the vacuum being created and the own weight of the piston during sinking. Because of the unlimited expansion possibility during lifting of the piston the fuel
consumption was reduced to one third of the consumption of the Lenoir engine, and now the engine consumed only 1.08 m3 of illuminating gas per kWh. As can be seen, the efficiencies of the atmospheric gas engine were quite acceptable already, however the desired higher performance was not achieved.
The atmospheric engine consumed "only" approx. 2.4 m3 of illuminating gas per hour and yielded also max. 2.2 kW. (With an engine height of "only" 2 m, for example, it was mere 0.7 kW). But what was important at that time was the reduction of gas consumption to one third with the same performance and the significantly calmer running.
On the assumption that the illuminating gas of that time had a heating power of approx. 5500 kcal/m3, a surprising conversion result is obtained: 5500 kcal/m3 = 23027400 J/m3 = 6.39 kW/m3, that was a consumption of approx. 15,4 kW per 2,2 kW of engine performance, after all an efficiency of approx. 14 %.
An explosion is a very hot combustion generating the corresponding maximum pressure in a closed compartment. Already with Otto's gas engine the uncompressed explosion with subsequent expansion was the reason for the reduced gas consumption. This process can be equated to an improvement of efficiency. The then achieved relatively high efficiency of 14 % is surprising when comparing it to that of modern engines which, too, reach only a 17% .efficiency with medium speed. This meagre increase within one hundred years of engine development is a shame. Moreover these "modern efficiencies" will drop down to 5% under load and at a correspondingly high speed. As more combustion air can only be drawn in when the speed is increased, the combustion time becomes shorter with increased speed and thus impairs the efficiency (the actual handicap of the four-stroke engine).
However, with Otto's atmospheric gas engine this usual drop of efficiency could not be observed to the same extent because the efficiency remained nearly constant though the engine rotated more slowly under load, for the expansion
could adjust itself variably to the amount of fuel or gas, i.e. lift the piston more or less (variable final piston position).
Logically the performance of Otto's gas engine was too low because the low rate of 150 strokes/min plus the atmospheric suction force that had to do the work alone could not bring a satisfactory result. If Otto had then been able to perform more strokes per minute, e.g. eight thousand strokes per minute as with the single-stroke engine, his engine would certainly have achieved a remarkable performance and a very good efficiency. Therefore Otto's explosion combustion without compression and without space limitation of the subsequent expansion would have been a good start for an improvement of efficiency already then. This idea seems to have been lost or was not recognized and therefore not pursued. Taken up again, the conception of the single-stroke engine based on this principle of explosion plus expansion is now to bring a change. Now eight to sixteen explosion combustion strokes plus expansion are performed within two rotations instead of just a "slow" stroke combustion without expansion as it is the case with the four-stroke engine. This single-stroke cycle makes the exceptional improvement of efficiency and simultaneous increase of performance more comprehensible.
Explosion combustions develop a high temperature and thus a high pressure. Therefore the explosion is a desired effect of the single-stroke combustion. By contrast, an explo- sion is avoided with all technical and chemical tricks with the four-stroke combustion because of the knocking risk.
Considering the parameters mentioned above, it is possible to reach the efficiency mentioned below. It has already been pointed out that the efficiency will change only slightly with changing engine load because the existing expansion possibility has made the engine very elastic. This means that the combustion air is dosed to the fuel, rather than the fuel to a constant volume of air (cylinder capacity) as with the four-stroke combustion.
An uncompressed air volume drawn in atmospherically has always the same oxygen portion of approx. 20% for combustion as an equal compressed volume. The smooth four-stroke combustion aimed at by Otto because of the increase of performance was obtained by compression of a rich mixture or by exhaust-gas recycling. However, both measures have to be judged as a deterioration of efficiency, which helped only to increase the performance. The flame front is cooled from the top to the bottom dead centers to avoid an explosion, but nevertheless it must not go out, which involves enourmous control.
However, the aim of the single-stroke explosion is to complete the combustion in the first quarter or third of the stroke as a real optimum explosion in order to expand subsequently. This can be done under of 2 to 6 bar pressure. In both cases enough time remains for expansion. The extent of compression depends solely on the performance required, which can be adjusted via the compression relief (by-pass).
Certainly Otto could perform faster and more powerful combustions with his four-stroke method, but at the price of high environmental pollution, i.e. very low efficiency. And nothing has changed until today.
This type of combustion by means of a braked flame front has not changed with all high-powered engines. Test-stand measurements of the useful efficiency are camouflaged, and the consumption per one hundred kilometers is preferably indicated instead of the consumption for a performance under 10% load. For it is generally known that with high engine speeds and a ten-percent load the net efficiency may go down to meagre five percent. Therefore one prefererably resorts to the thermal efficiency when specifying combustion engines and is prepared to accept the very bad net efficiency achieved. In plain English this means: since one has not yet been able to extend the time of combustion and to avoid thermal losses, nothing has changed.
Explosion and expansion comes up to a reduction of combustion time. This is made possible by the single-stroke combustion, a combustion with nearly no
thermal loss in the sense of rotation where compression is separated from work and the mixture explodes in a heat-insulated (ceramic) cylinder. Therefore this explosion process can be optimally utilized because the explosion is hot and short, the complete power acts only on the rotor and the expansion can act on the piston for a relatively long time and isobarically (with slightly sinking pressure). At the end of the stroke the pressure is released abruptly. The exhaust is relieved at the exhaust slot almost isochorically.
U1 = 1000 revolutions per min U2 = 1500
U3 = 2000 U4 = 3000
A very simple rough calculation of consumption and efficiency may help to make the function of the single-stroke engine more transparent.
1.) Assuming an explosion stroke volume of approx. 2 x 200 cm3 = 400 cm3, for one rotation a segment piston displacement of 800 cm3, 30 kWh engine power and a consumption between 120 and 140g/kWh.
2.) With 130g/kWh as average consumption of the single-stroke engine, a 30-kWh single-stroke engine will consume 3900g of Diesel oil per hour. According to the specific gravity of 0.83, this value corresponds to 4699 cm3 = approx. 4,7 liters/h (Attention! not per 100 km).
3.) The most efficient single-stroke engine speed is between 1500 and 2000 rpm. For this example this means 90,000 revolutions per hour at an advantageous speed of 1500 rpm.
4.) The single-stroke engine makes 4 strokes per revolution, i.e. 360,000 strokes/h
(With external working chambers 8 strokes per rev., i.e. 720,000 strokes/h)
5.) Hence follows an injection quantity per stroke of 3900g : 360,000 strokes = 0.0108g per stroke - or rounded up approx. 0.012 cm3 of Diesel oil per stroke.
6.) Stoichiometrically 14.7 kg of air are required for combustion of 1 kg of Diesel oil, i.e. for the stroke volume of 0.0108 g/ Diesel x 14,7 = 0.1587 g air
1cm3 air = 0.001293 g > 0.1587g air : 0.001293 g/cm3 = 122.7 cm3 of air
This can be generously rounded up to approx. 124 cm3 , a meagre explosion.
7.) When 124 cm3 of mixture are compressed to 5 bar, this corresponds to approx. 25 cm3 which are charged into the first stroke quarter at 5 bar
(100cm3 : 4 = 25 cm3), explode immediately in the sense of rotation and above all can expand without afterburning.
8.) Calculation of consumption and efficiency: 1kg of Diesel oil = 44,500 kJ = 10,632 kcal/kg = 12,360 W
30 kW at 100 % efficiency correspond to 2.42 kg of Diesel oil = 2.91 liters
30 kW at 65 % efficiency correspond to 3.72 kg of Diesel oil = 4.48 liters
9.) 0.0108 g of Diesel oil correspond to (12360 W x 0.0108g) : 1000 = 0.133 W/stroke
0.133 W per stroke x 360,000 strokes/h = approx. 48,000 W = 48 kWh (theoretically)
of which approx. 31 kW engine power** = 65% effciency* are left.
*This calculation shows that power and efficiency are approaching, i.e. the efficiency will be maintained even at low speed. The speed depends on the average circumferential speed of the rotary piston of approx. 12 m/s and is between 1000 rpm and max. 2000 rpm. This low speed is the best prerequisite for optimum ceramic design of the engine.
** Even by present-day standards an engine power of only 25 kWh and an efficiency of 50% would be a considerable and acceptable result !
If you have any patent-related questions or consider any contractual arrangements, please contact the patent attorney
If you have any patent-related questions or consider any contractual arrangements, please contact the patent attorneys:
OLBRICHT & BUCHHOLD Am Weinberg 15
DIPLOM PHYSIKER STAATL. GEPR. ÜBERSETZER D - 35096 Niederweimar
EUROPEAN PATENT ATTORNEY Phone: 49-6421-7 86 27
Fax: 49-6421-71 53
Patent specification EP 0 602 272 B1
Claims 1 2 3 4 5 6 7
specification English 13 to side 15
Fig. 1 Fig.2 Fig.4
89 99 100 101 102 103
specification French 15 to side 17
Features of the single-stroke engine
1. Within two four-stroke rotations there are eight single-stroke working cycles, each of which has the same duration relative to the rotational speed as the four-stroke cycle.
2. There are no sealing strips at all, therefore no problems with wear. Because of the simple geometry, the engine is extremely suitable for technical ceramics.
3. There are no lubrication problems in the explosion area, the compressor is lubricatedwith the bio-oil fuel or with diesel oil mixtures.
4. Wear and service life correspond to the service life of the synchronizing gears and of the friction bearings.
5. Because of the uniform load on the rotor owing to the symmetrical explosions, it may be taken into account to replace the friction bearings by cheaper ball or roller bearings.
6. The rotating engine parts, rotary piston and sealing rolls, rotate without contacting and without any unbalance.
7. A separate flywheel is not necessary because the driving pulses are performed on the rotor circumference ( 4 to 8 times per rotation).
8. Dead centers are replaced by turning points which are passed without reduction of piston speed.
9. The segment lifting cylinders and the rotary piston wings are used twice within one rotation, which doubles the performance per unit of displacement and reduces the cold surfaces of the cylinder wall by half.
10. The segment lifting cylinders and the rotary piston wings are operated with an incan- descent layer of 500 to 800 °C (metal or ceramic).
11. Piston and sealing rolls rotate without contacting and without sealing strips.
12. Sealing is ensured by the burnt-off material. Any excess is worn off per rotation (different peripheral speeds).
13. Sealing in the cold compressor is effected by the injected fuel forming a constant oil film which builds up an oil sealing bead on the contact surfaces during rotation.
14. Compression is limited to 2 to max. 6 bar. This is also the charging pressure.
15. With low performance the engine is charged with 2 bar only, which saves compression energy.
16. Ignition of diesel oil is also possible at 2 bar, if necessary by means of spark plugs during start. With hot chamber operation, the process takes place continuously.
17. Vegetable oil is the preferred fuel for single-stroke engines; biogas mixtures, waste incineration gases, but also other weak gases can be used as well. Alternatively, heavy oils, diesel oil and natural gas are also suitable.
18. Pure oxyhydrogen as an alternative for the fuel cell can be converted into electricity at a high and better efficiency than that of the fuel cell.
19. Sufficient fresh-air supply is ensured by increasing the compressor volume against the combustion compartment volume (no other supercharger is required).
20. Air is dosed to fuel, not fuel to air.
21. There is no gas change. Each explosion process is a self-contained process.
22. The process of combustion by explosion takes place in the hot cell at a temperature level between 400 °C and 800 °C.
23. But also in this case, compression is cold and combustion by explosion is hot.
24. No lubrication of the rotary piston in the combustion compartment is necessary because the aim is to keep the rotary bodies at red heat only on the surface.
25. Lateral lubrication of the rotating elements can be achieved by the fuel used, with bio fuels being more suitable. The fuels lubricate laterally and are then burnt. A short self-renewal ..
26. The torque is transmitted to the engine shaft symmetrically on both sides and vibrationfree. The operation of the engine can be compared to that of a three-phase motor, for 3000 possible explosion pulses come close to alternating current of 50 cps.
27. The fuels are burnt by explosion according to their natural properties, without disturbing ignition delay and upper temperature limit.
28. The time saved by explosion is used for expansion, which comes up to an extension of the combustion time.
29. It is possible to use spark ignition, also permanent glow plug ignition depending on the fuel or continuous self-ignition in the hot chamber.
30. Mixture concentrations for better ignition quality are unnecessary because the ignition quality is assisted by the overcritical collision of the charges and by the hot cylinder wall.
31. There are no reactions by suction and exhaust vibrations because the working stroke is completed before the exhaust opening and residual gases have been exhausted before.
32. The engine can be operated fully heat-insulated.
33. Recuperative preheating of suction air is possible with the single-stroke engine, which results in faster explosions so that the rotational speed can be increased without the disadvantage of decreasing efficiency.
34. When the suction air is heated, the fuel is adjusted to the reduced oxygen content of the compressed hot air. The reduced performance per stroke is compensated by the higher speed.
35. When the suction air is preheated by the exhaust gases, these can be reduced down to the dew point limit, which has a positive effect on the efficiency.
36. There are no problems with residual gases after the combustion by explosion because all residual CO and HC gases are also burnt owing to the explosion at a high temperature.
37. The relatively long four-stroke flame front combustion is replaced by eight or sixteen - by at least eight to sixteen times shorter - explosions which release the heat content of the small fuel portion in the 500 °C to 800 °C hot explosion chamber very effectively as total quantity of heat.
38. Owing to the ceramic construction, the single-stroke engine can be operated advanta- geously at high temperatures. Cylinder and piston are made of porous silicon carbide or nitride ceramics with poor heat conductivity.
39. Charging within one rotation is made at a charging pressure of 4 bar via 8 lateral ports so that the mixture columns in the middle of the cylinder collide at supersonic speed. Reduction of the charging volume per charging channel by 1/4 furthers the charging process.
40. The unused residual heat is small at an efficiency of 80%. Because of this lower heating inside the engine, the engine need not be cooled, but can be completely insulated (hot- chamber radial pulse turbine).
41. Adjusted torque owing to speed-dependent charging: at high speed the torque is low, at low speed the torque is high. A very good constellation for an engine.
42. Because of the explosion and the very small exploding quantities of mixture, the single-stroke process is so quick that there are hardly any thermal losses.
43. The charging moment is the explosion moment during 1/3 of the stroke, expansion during 2/3 of the stroke and exhaust. Simplification of ignition control.