Steam engines, like traditional internal combustion engines, have a common drawback - the reciprocating movements of the piston must be converted into rotational movements of the wheels. This is the reason for low efficiency, high wear of the main elements.
Many engineers have tried to solve this problem by inventing an engine internal combustion, all the details of which would only rotate. However, a self-taught mechanic who did not graduate from either a higher or even a secondary specialized educational institution was able to invent such a unit.
A bit of history
In 1957, the little-known mechanic-inventor Felix Wankel and NSU lead engineer Walter Frede became the first to decide to install a rotary piston engine in a car. "Experimental" became the NSU Prinz. The original design was far from perfect. For example, candles had to be changed almost after complete disassembly unit. In addition, the reliability of the motor remained in doubt, and one could not mention efficiency.
After many tests, the concern started producing cars with a traditional internal combustion engine. However, the first rotary piston DKM-54 could show great potential.
That's how original type of internal combustion engine got his chance to be introduced into the production of cars. In the future, it was constantly being refined, but the prospects for a rotary piston engine were already obvious then. RPD is included in the classification rotary motors as one of the 5 representatives of the line.
By the 80s of the 20th century, only Japanese by Mazda. VAZ also showed attention to this motor. In the USSR, gasoline was quite cheap, and such a unit had a fairly large capacity. However, by 2004, the production of cars with such an engine had ceased. Japan has become the only country in which the development of a rotary engine continues.
There are many varieties of rotary units. Their only difference is the surface of the body and the number of edges made on the rotor. Various layouts of such motors are used in auto and shipbuilding.
Advantages
The Wankel engine has had many advantageous advantages over piston engines since its inception. The unit has been constantly improved, which made it possible to increase its efficiency and productivity.
Among the advantages of "Wankel" are:
- Small dimensions and weight. "Wankel" is almost 2 times smaller than the piston ICE, which has a positive effect on the controllability of the car, contributes to the optimal installation of the gearbox, and allows you to make the interior much more spacious.
- Compared to two-stroke motor, the Wankel engine has far fewer parts. This is more beneficial in terms of repair.
- doubled big power than standard internal combustion engines.
- Greater smoothness of work - the absence of forward-return movements has a positive effect on ride comfort.
- Possibility of refueling with low-octane gasoline.
All elements of the motor rotate in the same direction. This improves the internal balance of the unit and reduces vibrations. Wankel delivers power evenly and smoothly. During the time that the rotor turns 1 time, the output shaft makes 3 turns. Each combustion is carried out for 90 phases of rotor rotation.
This suggests that with 1 rotor it is capable of delivering power for ¾ of each turn of the output shaft. A 1-cylinder engine can only deliver power for ¼ of each turn of the output shaft.
Flaws
The disadvantages of the engine include unusualness for owners and mechanics. Such an assembly requires changing many habits. For example, it will not work to slow down the RPD, and the assault on “pull-in” climbs is doomed to failure. The compact motor has low inertia, which cannot be said about massive piston internal combustion engines. With frequent startups and shutdowns, candles are “thrown”. Some motorists also refer to the sound of the engine as a disadvantage.
More serious are the organic flaws of the rotary piston unit. First, it has an increased fuel consumption. This is easily explained by the non-optimal shape of the chamber, which loses heat through the walls. In addition, the motor "eats" a lot of oil. The life of the Wankel is lower than that of a standard ICE - the rotor seals wear out regularly.
Rigidity plays a significant role external characteristics rotary piston motor. To control a machine with such an engine, it is necessary to manipulate the gear lever quite often. This is due to the need for a short gear range and an increased number of gears.
The ideal option is to install a variator. However, automatics do not take root on sports cars, and family-type cars require more efficiency.
The disadvantages of RPD are similar to the disadvantages of two-stroke piston units. Interestingly, it can be cured in the same ways. Increased fuel consumption goes astray direct injection, lack of elasticity - by the installation of variable phases. This improves economy and manageability. Also, to increase elasticity, the configuration of pipelines is changed. Such changes were made on the Mazda RX-8 engine.
How does it work
The Wankel engine works according to a principle that is quite simple to explain even to a person ignorant of mechanics. The unit has a minimum of details, which allows you to quickly understand which systems are involved at certain intervals.
The engine piston in the RPD is replaced by a rotor with 3 faces, which transmits the pressure force of the combustible gases to the eccentric shaft.
The stator has an epitrochoidal configuration of internal surfaces. It has a high wear resistance because it has a special coating. There are seals at the tops of the rotor, and recesses on the surface of the stator - they are a kind of chambers in which combustion occurs. The shaft rotates on special bearings. They are placed on the body. The shaft is also equipped with an eccentric - the rotor rotates on it.
The gear is built into the housing. It is engaged with the rotor gear. The mutual action of these gears creates the movement of the rotor. This allows you to form 3 chambers that constantly change their volume.
The ratio of the gears is 2:3, which provides one rotation of the shaft per rotation of the rotor by 120 degrees. When the rotor makes a complete revolution, all chambers perform a four-stroke cycle. Combustible gases act on the shaft eccentric through the rotor - this is how torque occurs.
There are 3 chambers between the rotor and the stator. Intake occurs when one of the tops of the rotor begins to cross the fuel injection inlet. The volume of the chamber increases, which causes the mixture to fill it. The next vertex closes the window. Like a conventional engine piston, the rotor compresses the mixture before it ignites.
It shrinks, with the greatest compression a spark occurs in the chamber. The result is a workflow. After the outlet window under the pressure of the exhaust gases opens, and they leave the chamber.
With one revolution of the rotor, the engine performs 3 cycles - this makes the use of balancing devices unnecessary.
There are weak links in the workflow. The first is an increased load on the seals, and the second is an excess of dynamic phase overlap. The configuration of the combustion chamber is not optimal either. However, there is a positive point - if you increase the speed, the speed of the flame spreading increases faster than the fuel mixture flows.
This allows the use of gasoline with a low octane rating for RPD. The principle of operation of Wankel is quite simple, which at one time attracted the attention of many car manufacturers to the invention.
Not every car enthusiast knows that Wankel is one of the 5 subtypes in the classification of rotary engines.
Compactness, speed, high performance - isn't this what almost all motorcycle manufacturers are striving for? Definitely, it is. However, the rotary motor did not take root in the motor world. All bets are placed on classic piston engines.
However, there have been a few exceptions in the history of motorcycle production. For example, in 1974 Hercules released a mass series of Wankel, which are equipped with a KC-27 engine. These were rotary units, which were equipped air-cooled. The engine had a volume of 294 cu. see. The power of the units was 25hp. To lubricate the unit, the oil had to be poured into the fuel tank on its own.
In the early 1980s, the rotary engine was used to power Norton motorcycles. Despite the fact that prototypes of such engines appeared in the 1970s, Norton engineers successfully introduced RPD into the sport. By the end of the 80s they had no equal.
Today the company produces a 588cc model with two NRV588 rotors. Norton engineers are also developing a 700cc version called the NRV700. She represents powerful sportbike, equipped with an injection 170-horsepower Wankel engine.
As you can see, the era of rotary motors has not yet arrived. Piston systems and remained a leader in the field of auto and motorcycle construction. Owners of bikes with rotary engines can form only a small circle of Wankel fans. Renewed interest in Norton's Wankel signals a rise in developments and advances in this area.
One of the reasons why the engine is not produced to equip cars and motorcycles is the need for precision equipment in its production. The slightest marriage causes engine failure. This does not yet allow the rotary unit to replace the piston engine, even in narrow industries.
Internal combustion engine, a heat engine in which the chemical energy of the fuel burning in the working cavity is converted into mechanical work.
by gender ICE fuel divided into engines:
liquid fuel;
gas.
According to the way the cylinder is filled fresh charge:
four-stroke;
two-stroke.
According to the method of preparing a combustible mixture from fuel and air, engines with:
external mixing;
internal mixing.
Engines with external mixture formation include carburetor, in which combustible mixture from liquid fuel and air is formed in the carburetor, and gas mixing, in which a combustible mixture of gas and air is formed in the mixer.
In an internal combustion engine with external mixture formation, the working mixture in the cylinder is ignited by an electric spark.
In engines with internal mixture formation (diesels), the fuel spontaneously ignites when it is injected into compressed air heated to a high temperature.
Duty cycle 4-stroke carburetor internal combustion engine takes place in 4 strokes of the piston (stroke), i.e., in 2 revolutions of the crankshaft.
At the 1st stroke - intake - the piston moves from top dead center (TDC) to bottom dead center(n. m. t.). Inlet valve at the same time, it is open and the combustible mixture from the carburetor enters the cylinder.
During the 2nd stroke - compression - when the piston moves from n. m. t. to v. m.t., the inlet and outlet valves are closed and the mixture is compressed to a pressure of 0.8-2 MN / m2 (8-20 kgf / cm2). The temperature of the mixture at the end of compression is 200-400°C. At the end of compression, the mixture is ignited by an electrical spark and the fuel is burned. Combustion takes place at a piston position close to c. m. t. At the end of combustion, the pressure in the cylinder is 3-6 MN / m2 (30-60 kgf / 1 cm2), and the temperature is 1600-2200 ° C.
The 3rd cycle of the cycle - expansion - is called the working stroke; during this cycle, the heat received from the combustion of the fuel is converted into mechanical work.
The 4th stroke - release - occurs when the piston moves from n. m. t. to v. m. t. with the exhaust valve open. The exhaust gases are displaced by the piston.
The working cycle of a 2-stroke carburetor internal combustion engine is carried out in 2 strokes of the piston or in 1 revolution of the crankshaft. The processes of compression, combustion and expansion are almost identical to the corresponding processes of a 4-stroke internal combustion engine. Ceteris paribus, a 2-stroke engine should be 2 times more powerful than a 4-stroke engine, since the power stroke in a 2-stroke engine occurs 2 times more often, however, in practice, the power of a 2-stroke carbureted internal combustion engine is often not only does not exceed the power of a 4-stroke with the same cylinder diameter and piston stroke, but it turns out to be even lower.
This is due to the fact that the piston makes a significant part of the stroke (20-35%) with open windows, when the pressure in the cylinder is low and the engine practically does not work; purging the cylinder requires power to compress the air in the purge pump; cleaning the cylinder space from the products of gas combustion and filling it with a fresh charge is much worse than in a 4-stroke internal combustion engine.
The working cycle of a carburetor internal combustion engine can be carried out at a very high shaft speed (3000-7000 rpm). Engines racing cars and motorcycles can develop 15,000 rpm or more.
A normal combustible mixture is about 15 parts air (by mass) and 1 part gasoline vapor. The engine can run lean (18:1) or rich (12:1). Too rich or too lean mixture causes a strong decrease in the combustion rate and cannot ensure the normal course of the combustion process.
The power regulation of the carburetor internal combustion engine is carried out by changing the amount of the mixture supplied to the cylinder (quantitative regulation). High speed and favorable ratios of fuel and air in the mixture provide obtaining high power per unit volume of the cylinder of a carburetor engine, therefore, these engines have relatively small dimensions and weight [1-4 kg / kW (0.75-3 kg / hp)].
The use of low compression ratios causes moderate pressures at the end of combustion, as a result of which parts can be made less massive than, for example, in diesel engines.
With an increase in the diameter of the cylinder of a carburetor internal combustion engine, the tendency of the engine to detonate increases,
As you know, the principle of operation of a rotary engine is based on high revs and the absence of movements that distinguish ICE. This is what distinguishes the unit from. RPD is also called the Wankel engine, and today we will consider its operation and obvious advantages.
The video shows the device and principle of operation of the Zheltyshev rotary engine:
Surprisingly, they tried to put RPD into operation in our country as well. Such an engine was designed to be installed on the VAZ 21079, designed as vehicle for special services. But the project, unfortunately, did not take root. As always, there was not enough state budget money, which is miraculously pumped out of the treasury.
But the Japanese managed to do it. And they do not want to stop at the achieved result. According to the latest data, the manufacturer Mazda will improve the engine and will soon come out with a completely different unit.
Let's look inside the RPD
The scheme of operation of a rotary engine is something completely different than a conventional internal combustion engine. First, we should leave the design of the internal combustion engine as we know it in the past. And secondly, try to absorb new knowledge and concepts.
RPD is named so because of the rotor, that is, which moves. This movement transfers power to the clutch and gearbox. Essentially, the rotor pushes energy from the fuel, which is then transferred to the wheels through the transmission. The rotor itself is necessarily made of alloy steel and has, as mentioned above, the shape of a triangle.
The video shows the principle of operation of the Zuev rotary piston engine:
The capsule where the rotor is located is a kind of matrix, the center of the universe, where all processes take place. In other words, it is in this oval case that:
- mixture compression;
- fuel injection;
- supply of oxygen;
- mixture ignition;
- return of burnt elements to the outlet.
In a word, six in one, if you will.
The rotor itself is mounted on a special mechanism and does not rotate around one axis, but rather runs. Thus, they create isolated friend from each other cavities inside the oval body, in each of which one of the processes takes place. Since the rotor is triangular, there are only three cavities.
It all starts like this. In the first cavity formed, suction occurs, that is, the chamber is filled with air, which is mixed here.
After that, the rotor rotates and pushes this mixed mixture into another chamber. Here the mixture is compressed and ignited with two candles.
The mixture then goes into the third cavity, where parts of the used fuel are displaced.
This is the complete cycle RPD work. But not everything is so simple. We have considered the RPD scheme only from one side. And these actions happen all the time. In other words, processes occur immediately from three sides of the rotor. As a result, in just one revolution of the unit, three cycles are repeated.
In addition, it was possible to improve the rotary engine. Today, Mazda rotary engines have not one, but two or even three rotors, which greatly improves performance, especially when compared with conventional engine internal combustion. For comparison: a two-rotor RPD is comparable to a six-cylinder internal combustion engine, and a 3-rotor RPD is comparable to a twelve-cylinder. So it turns out that the Japanese turned out to be so far-sighted and immediately recognized the advantages of a rotary engine.
Again, performance is not the only virtue of RPDs. He has many of them. As mentioned above, a rotary engine is very compact and uses as many as a thousand parts less than in the same internal combustion engine. There are only two main parts in the RPD - a rotor and a stator, but you can’t imagine anything simpler than this.
The principle of operation of a rotary piston engine made at one time many talented engineers raise their eyebrows in surprise. And today, talented engineers deserve all kinds of praise and approval. It's no joke to believe in the performance of a seemingly buried engine and give it a second life, and what a life!
They all put rotary engines under the hood of their cars. And the Japanese still use the rotor to this day - however, already in a modern, improved modification. What is the success of the Wankel rotary engine?
The principle of operation of a rotary piston engine
The rotary performs the same four cycles as its piston counterpart: intake, compression, power stroke, exhaust. But the rotor works differently. A piston engine performs four cycles in one cylinder. And although the rotary performs them in one chamber, each of the measures takes place in its separate part. That is, the cycle seems to be performed in a separate cylinder, and the piston "runs" from one cylinder to another. At the same time, there is no gas distribution mechanism in the rotary motor. Unlike a piston engine, all the work is done by intake and exhaust ports located in the side housings. The rotor rotates and regulates the operation of the windows: opens and closes them.
By the way, about the rotor. Needless to say, it is the main element of the motor, it was the rotor that gave the name to the engine itself. What is this detail? The rotor has a triangular shape, it is immovably fastened to the eccentric shaft and not centered on it. When rotated, the element describes a capsule shape, rather than a circle, due to its location. The rotor transfers power from the motor to the gearbox and clutch, in other words, pushes the burnt fuel out and transfers the rotation to the transmission to the wheels. The cavity in which the rotor rotates is made in the form of a capsule.
The principle of operation of a rotary piston engine is as follows. During rotation, the rotor creates around itself three cavities isolated from each other. This happens due to the capsule shape of the cavity around the rotor and the triangular shape of the rotor itself. The first cavity suction cavity It mixes fuel with oxygen. Further, the mixture is distilled into the second chamber by the movement of the rotor and compressed there. Here it is ignited by two candles, it expands and pushes the piston. Forward motion the rotor scrolls, the next cavity opens, where exhaust gases and fuel residues exit.
Disadvantages and advantages of a rotary engine
Like any other internal combustion engine, a rotary engine has both pros and cons. First, consider its advantages over other engines.
1. The performance of the rotary engine is several times higher than the others. While in conventional internal combustion engines one cycle passes per revolution, then in a rotary motor - three(suction, compression, ignition). Moreover, modern engines are equipped with two or three rotors at once, so a 2-rotor engine can be compared with a 6-cylinder conventional internal combustion engine, and a 3-rotor engine with 12 cylinders.
2. Small number of parts. The simplicity of the motor design (rotor and stator) allows the use of fewer parts. Statistics say that there are 1,000 more parts in an internal combustion engine than in a rotary engine.
3. Low level vibration. The rotor rotates in a circle without reciprocating motion. Accordingly, the vibration is practically not noticeable. In addition, there are usually two rotary engines, so they balance each other's work.
4. High dynamic characteristics . In one revolution, the engine performs three cycles. Therefore, even at low speeds, the engine develops high speed.
5. compactness and small weight. Due to the simplicity of design and the small number of parts, the motor has a small weight and size.
Despite the many advantages, the motor also has several disadvantages that do not allow car companies to massively use it on their cars.
1. Tendency to overheat. During burning working mixture radiant energy is produced, which aimlessly leaves the combustion chamber and heats the engine. This is due to the shape of the camera, which resembles a capsule or lens, that is, having a small volume, it has a large working surface. To prevent energy from escaping, the chamber had to be spherical.
2. Regular replacement oils. The rotor is connected to the output shaft by an eccentric mechanism. This method of connection causes additional pressure, which, coupled with high temperature heats up the engine. That is why you need to periodically give the car for overhaul and change the oil. Without an oil change, the engine fails.
3. Regular replacement of seals. On a small area of contact between the rotor and the shaft, high blood pressure. Seals wear out, leaks form in the chambers. As a result, the toxicity of the exhaust and the drop in efficiency increase. By the way, on new models this problem was solved using high-alloy steel.
4.High price. For rotary engines, parts must be produced with high geometric accuracy. Therefore, expensive equipment and expensive materials are used in the production of rotary engines. As a result, the price of a rotary motor is high despite the apparent simplicity of the design.
The use of rotary engines: from invention to the present day
Engineers have been developing a rotary engine for a very long time. Inventor steam engine James Watt laid the foundation for the dream of a rotary engine. In 1846, engineers had already determined the shape of the combustion chamber and the basis for the operation of a rotary internal combustion engine. But the engine remained a dream. But in 1924 young and talented Felix Wankel began a thorough practical work on the creation of a rotary engine. The twenty-two-year-old engineer had just graduated from high school and entered the publishing house of technical literature. It was then that Wankel began to draw the project own engine based on extensive theoretical knowledge from literature. Having created his own laboratory, the engineer began to receive patents for products. In 1934 Wankel applied on the first rotary engine.
But fate decreed otherwise. The talented engineer was noted by the authorities, and he began work on the largest automobile concerns fascist Germany. He had to put his projects on hold. After the war the engineer was in jail, as an accomplice of the Nazi regime, and the French took out his laboratory. And only in 1951, the scientist restored the name by starting to work for a motorcycle company. There he rebuilt his laboratory and brought in another scientist named Walter Freude to the rotary engine project. Together they produced the first rotary engine on February 1, 1957. Initially, it ran on methanol, but by July the engine was switched to gasoline. In the 50s, Germany began to recover from the consequences of the war, respectively, and the car companies got rich.
The company NSU, where Wankel and Freude worked, was preparing to mass-produce cars with a rotary engine. In 1960, the NSU Spider was shown in Munich with a Wankel engine under the hood. And in 1968, the NSU Ro-80 came out, which influenced the further automotive industry. The car accelerated to 180 km / h, from a standstill, the car accelerated to 100 km / h in 12.8 s. The Ro-80 became the car of the year, and many concerns bought the rights to the Wankel engine. But due to shortcomings in the design of the engine and the high cost of production, companies refused to mass-produce machines with a rotary engine. But there were prototypes.
For example, Mercedes-Benz, which released the C111 car in 1970. Stylish orange car with a streamlined reliable body, it accelerated to 100 km / h in 4.8 s. But the gluttony of the car did not allow the company to mass-produce C111.
Interested in the rotor and. Already in 1972, the first Corvette with a two-section rotary engine was presented to the public. Four-section Corvettes appeared in 1973, but in 1974, due to a lack of money, Chevrolet shelved work on rotary engines. Neighboring France also adopted Wankel engines. In 1974 Citroen company released on Citroen market GS Birotor. Under the hood was a two-section Wankel engine. But the car was not popular. In two years, the French company sold only 874 cars. In 1977, Citroen recalled the rotary cars to eliminate them, but it is likely that 200 of them survived.
In the USSR, they also tried to use the Wankel engine. They could not buy a license at the VAZ factories, so they copied a single-section rotary engine from the NSU Ro-80. On its basis, in 1976, the VAZ-311 engine was assembled. Refinement lasted 6 years. First serial VAZ with a rotor under the hood was 21018. But the model failed miserably. All 50 prototypes broke down. In 1983, two-section rotary models. Equipped with such a motor, Zhiguli and Volga easily overtook foreign cars. But then the design bureau was distracted from the automotive industry and unsuccessfully tried to use a rotary engine in aviation. This led to the fact that the developing industry stopped at the VAZ-415 model in 1995.
Until 2012, mass-produced Mazda model RX-8, with an improved Wankel engine. In general, the Japanese are the only ones who have mass-produced rotary machines since 1967. In the 70s Mazda years introduced the RX brand, which stands for the use of rotary motors. The Japanese put the rotor on any car, including pickups and buses. Maybe that's why the RX-8 has excellent technical and environmental performance, which was so unusual for the first cars with the Wankel engine.
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Wankel engines, known as RPD rotary piston engines, were once considered the engines of the future. Let's talk about the advantages of the Wankel engine and analyze the principle of operation of the RPD.
Advantages and disadvantages of RPD
Advantages:- smaller dimensions and weight;
- fewer parts (even in comparison with a two-stroke piston internal combustion engine);
- twice as much power with the same dimensions as traditional internal combustion engines;
- smooth operation as a result of the absence of reciprocating moving parts;
- possibility of consumption of low-octane gasoline.
- inefficient combustion process, which means an increase in fuel consumption and toxicity of exhaust gases;
- lubrication "for burnout", which entails high flow oils;
- the impossibility of production in areas intended for the production of traditional internal combustion engines;
- the transition to the production of RPD requires the replacement of the vast majority of equipment.
The disadvantages include the unusualness of the Wankel engine for both repairmen and owners. This motor requires a change of many habits. So, it is useless to slow down the RPD, even more so to storm the "pull-in" climbs. The compact rotor has low inertia, unlike the massive parts of a traditional internal combustion engine. Frequent starts-offs "throw" the candles. The sound of the motor is also unusual, although many consider this an advantage.
Much more serious are the organic flaws inherent in the RPD. First, this low elasticity characteristics and increased consumption fuel. The latter is explained by high heat losses through the walls of the chamber, which is far from optimal. Secondly, oil consumption is especially high. The resource of such a motor is also lower than that of a traditional one, due to rapid wear rotor seals.
An important role is also played by the rigidity of the external characteristics of the RPD, which requires more frequent manipulations of the gearshift lever - in practice, this is expressed in a "shorter" gear range, which means an increased number of gears. Installing a variator would be ideal, but on sports cars"automatic machines" did not take root, but it is strange to see RPD on a family car - if only because of insufficient efficiency.
Flaws rotary piston engines same as two-stroke piston engines. And many of them are "treated" in the same way. Increased "appetite" - direct fuel injection, lack of elasticity - variable phases and configuration of pipelines.
Principle of operation
The function of the piston in the RPD is performed by a triangular rotor, which converts the gas pressure force into the rotational movement of the eccentric shaft. The movement of the rotor relative to the stator is provided by a pair of gears, one of which is fixed on the rotor, and the second on the side cover of the stator.The configuration of the working surfaces of the rotor and stator is epitrochoidal. Working surface The stator has a wear-resistant coating. At the tops of the rotor, special seals are installed, on the working surfaces there are recesses that act as combustion chambers. The shaft rotates in bearings placed on the body and has a cylindrical eccentric on which the rotor rotates.
The gear is fixedly fixed on the motor housing. The rotor gear is engaged with it. The interaction of these gears ensures the orbital movement of the rotor relative to the body, as a result of which three separated chambers of variable volume are formed. gear ratio gears 2:3, so for one revolution of the eccentric shaft, the rotor rotates 120 degrees. For a full revolution of the rotor in each of the chambers, a full four-stroke cycle is completed. The torque is obtained as a result of the action of gas forces through the rotor on the shaft eccentric.
Three chambers are formed between the stator and the rotor, similar to the over-piston space of the internal combustion engine. The intake process begins when the top of the rotor crosses the edge of the intake window, after which the volume of the chamber increases and the combustible mixture enters there. When the next top of the rotor closes the inlet window, the mixture begins to compress, and at the moment of greatest compression a spark is supplied - the working stroke begins. Then the outlet window opens and the exhaust gases leave the chamber space.
Thus, for one revolution of the rotor, three cycles occur in the engine, which makes the use of balancing devices unnecessary, especially in two-section designs that have become overwhelmingly widespread.
There are two workflows weak links: high load on the seals and excessive amount of dynamic phase overlap. In addition, the configuration of the combustion chamber is far from optimal. But there is a big plus. As the speed increases, the speed of flame propagation increases. faster speed mixture flow. As a result of the requirement of the RPD for octane number fuel is lower than that of piston engines.
