Among the main areas of engineering research, such as electric vehicles, hybrid vehicles and hydrogen fueled vehicles. Hydrogen fuel and other, publicly available technologies for obtaining cheap energy, are strictly prohibited by the world's oil and industrial monopolists. However, progress cannot be stopped, and therefore, some enterprises and individual enthusiasts continue to create unique vehicles.
Today's topic of conversation concerns precisely pneumomobiles. The pneumomobile is, as it were, a continuation of the theme steam car, one of the many branches of the use of engines operating due to the difference in gas pressures. By the way, the steam engine was invented long before the first steam engine James Watt, more than 2 thousand years ago, Hero of Alexandria. Heron's idea was developed and embodied in a small cart by the Belgian Ferdinand Verbiest, in 1668
The history of the creation of a car brings us not much information about the successful and unsuccessful attempts of inventors to use a simple and cheap mechanism as an engine. In the beginning, there were attempts to use the force of a large spring and the force of a flywheel. These mechanisms have firmly established their positions in children's toys. But using them as an engine full size car seems unimportant. However, such attempts continue and it seems that in the near future, unusual cars will be able to confidently compete with cars equipped with internal combustion engines.
Despite the apparent futility of this area of work in the field of road transport, the pneumatic car has a lot of advantages. This is the extreme simplicity and reliability of the design, its durability and low cost. Such an engine is silent and does not pollute the air. Apparently, all this attracts numerous supporters of this type of transport.
The idea of using compressed air to drive mechanisms and vehicles arose long ago and was patented in Great Britain, back in 1799. Apparently it arose from the desire to simplify the steam engine as much as possible and make it extremely compact in order to be used on a car. Practical use 
air motor was implemented in America, in 1875. They built mine locomotives that worked on compressed air. The first passenger car with a pneumatic engine was first demonstrated in 1932 in Los Angeles.
With the advent of the steam engine, the inventors tried to install it on the "Self-Running Carriages", but the bulky and heavy steam boiler turned out to be unsuitable for this type of transport.
Attempts have been made to use an electric motor and batteries for self-propelled vehicles, and some progress has been made, but the engine internal combustion was out of competition at that time. As a result of fierce competition between him and steam engine, won after all the internal combustion engine. 
Despite many shortcomings, this engine still dominates today in many areas of human life, including all types of transport. About the shortcomings of the internal combustion engine and the need to find him worthy replacement, are increasingly spoken in scientific circles and written in various popular publications, but all attempts to launch new technologies into mass production are severely blocked.
Engineers and inventors create the most interesting and promising engines that can completely replace internal combustion engines, but the world's oil and industrial monopolists use their leverage to prevent the abandonment of internal combustion engines and the use of new ones. alternative sources energy. 
And yet, attempts to create a production car without an internal combustion engine, or with its partial, secondary use, continue.
The Indian company Tata Motors is preparing to start mass production of a small city car Tata AIRPOD, whose engine runs on compressed air.
Americans are also preparing for mass production six-seater CityCAT car, 
working on compressed air. With a length of 4.1m. and a width of 1.82m., the car weighs 850 kilograms. It can reach speeds of up to 56 km / h and cover a distance of up to 60 kilometers. The indicators are very modest, but quite tolerable for the city, taking into account the numerous advantages of the car and its very low cost. What are these advantages?
Everyone who owns a car, or is related to road transport, they know very well how complex the constructively modern car engine internal combustion. In addition to the fact that the engine itself is structurally quite complex, it requires a fuel dosing and injection system, an ignition system, a starter, a cooling system, a silencer, a clutch mechanism, a gearbox and a complex transmission.
All this makes the engine expensive, unreliable, short-lived and impractical. I'm not talking about the fact that exhaust gases poison the air and the environment. 
A pneumatic engine is the exact opposite of an internal combustion engine. It is extremely simple, compact, silent, reliable and durable. If necessary, it can even be placed in the wheels of a car. A significant disadvantage of this engine, which does not allow it to be freely used on vehicles, is a limited mileage from one refueling.
To increase the range of the pneumatic car, it is necessary to increase the volume of air cylinders and increase the air pressure in the cylinders. Both have severe restrictions on the dimensions, weight and strength of the cylinders. Maybe someday these problems will be solved, but for now, the so-called hybrid schemes of propulsion systems are being used.
In particular, for a pneumomobile it is proposed to use low power motor internal combustion, which constantly pumps air into the working cylinders. The engine runs constantly, pumping air into the cylinders, and turns off only when the pressure in the cylinders reaches the maximum value. This solution can significantly reduce gasoline consumption, carbon monoxide emissions into the atmosphere and increase the range of the pneumomobile. 
Such a hybrid scheme is universal and is successfully used, including on electric vehicles. The only difference is that instead of a compressed air cylinder, electric accumulator, and instead of an air motor - an electric motor. A low power internal combustion engine rotates electric generator, which recharges the batteries, and those, in turn, feed the electric motors.
The essence of any hybrid scheme in replenishing the expended energy with the help of an internal combustion engine. This allows the use of a lower power motor. It works in the most advantageous mode and consumes less fuel, and therefore emits less toxic substances. Pneumomobile, or an electric car get the opportunity to increase the mileage, because the expended energy is partially replenished, directly during the movement. 
During frequent stops at traffic lights, when coasting and descending slopes, the traction motor does not consume energy and the cylinders, or batteries, are cleanly recharged. During long stops, it is better to replenish energy reserves from a standard gas station.
Imagine that you arrived at work, the car is parked, and the engine continues to work, replenishing the energy reserves in the cylinders. Wouldn't this negate all the benefits of a hybrid car? Will it not turn out that the savings in gasoline will not be as significant as we would like?
In the days of my distant youth, I also thought about an air motor for a homemade car. Only the direction of my searches had a chemical character. I wanted to find a substance that would enter into a violent reaction with water, or another substance, while releasing gases. Then I could not find anything suitable and the idea was forever abandoned.
But another idea appeared - why not use a vacuum instead of high air pressure? If the compressed air cylinder is damaged in any way, or the air pressure exceeds the allowable one, then this is fraught with its instant destruction, like an explosion. This does not threaten a vacuum cylinder, it can simply be flattened by atmospheric pressure.
To obtain high pressure in a cylinder, about 300 bar, you need a special compressor. To obtain a vacuum in the cylinder, it is enough to let in a portion of ordinary water vapor. The cooled steam will turn into water, decreasing in volume by 1600 times and ... the goal is achieved, a partial vacuum is obtained. Why partial? Yes, because not every cylinder can withstand a deep vacuum. 
Then everything is simple. In order for the car to travel as far as possible on one cylinder, it is necessary to supply not air, but steam, to the air motor. Having done work, the steam passes through the cooling system, where it cools down and turns into water, enters the vacuum cylinder. That is, if steam is passed through the engine, say at 1600 cm3, then only 1 cm3 of water will enter the cylinder. Thus, only a small amount of water enters the vacuum cylinder and the duration of its operation increases many times over.
Let us return, however, to our pneumomobiles. The Indian company Tata Motors is going to mass-produce a compact city car powered by compressed air. The company claims that their pneumatic car is capable of accelerating up to 70 km / h and covering up to 200 kilometers with one refueling.
In turn, the Americans are also preparing a CityCAT six-seater pneumomobile for serial production. The declared characteristics mean that the car will be able to accelerate up to 80 km / h and the range will be 130 km. Another pneumomobile of the American company MDI, a small three-seater MiniCAT is also planned to be put into series.
Many firms became interested in pneumatic vehicles. Australia, France, Mexico and a number of other countries are also ready to start producing this unusual yet encouraging mode of transport. The internal combustion engine will still have to leave the arena and give way to another engine, simpler and more reliable. It is difficult to say when this will happen, but it will certainly happen. Progress cannot stand still.
First in the world stock car with a compressed air engine Indian company Tata, known throughout the world for the production of cheap vehicles for poor people.
The Tata OneCAT car weighs 350 kg and can travel 130 km on one supply of air compressed to a pressure of 300 atmospheres, while accelerating up to 100 kilometers per hour. But such indicators are possible only with the maximum filled tanks. The lower the air density in them, the lower the maximum speed indicator becomes.
4 cylinders made of carbon fiber with a Kevlar shell, 2 long and a quarter of a meter in diameter each, located under the bottom, contain 400 liters of compressed air at a pressure of 300 bar.
Inside, everything is very simple:
But this is understandable, since the car is positioned mainly for use in a taxi. By the way, the idea is not without interest - unlike electric vehicles with their problematic recyclable batteries and low efficiency of the charge-discharge cycle (from 50% to 70% depending on the level of charge and discharge currents), air compression, its storage in a cylinder and subsequent use are quite economical and environmentally friendly.
If you fill Tata car OneCAT air to the compressor station, it will take three to four minutes. “Pumping” with the help of a mini-compressor built into the machine, powered by an outlet, lasts three to four hours. " air fuel” is relatively cheap: if you translate it into a gasoline equivalent, it turns out that the car consumes about a liter per 100 kilometers.
In an air car, there is usually no transmission - after all, the air motor produces maximum torque immediately - even when stationary. The air engine also requires virtually no maintenance, standard mileage between two technical inspections is no less than 100 thousand kilometers. And he practically does not need oil - a liter of "grease" is enough for the engine for 50 thousand kilometers (for ordinary car about 30 liters of oil will be required).
The secret of a new car is that it four-cylinder engine with a volume of 700 cubes and a weight of only 35 kilograms, it works on the principle of mixing compressed air with outside, atmospheric air. This power unit is reminiscent of conventional engine internal combustion, but its cylinders have different diameters - two small, drive, and two large, working. When the engine is running outdoor air is sucked into small cylinders, compressed there by pistons and heated. Then it is pushed into two working cylinders and mixed there with cold compressed air coming from the tank. As a result air mixture expands and sets in motion the working pistons, and they - crankshaft engine.
Since no combustion occurs in the engine, its " exhaust gases» will only exhaust clean air.
Developers air engine from MDI calculated the total energy efficiency in the chain "refinery - car" for three types drive - gasoline, electric and air. And it turned out that the efficiency of the air drive is 20 percent, which is two times once again exceeds the efficiency of a standard gasoline engine and one and a half times - the efficiency of the electric drive. In addition, compressed air can be stored directly for future use, using unstable renewable energy sources such as wind turbines - then the efficiency is even higher.
When the temperature drops to -20C, the energy reserve of the pneumatic drive is reduced by 10% without any other harmful effects for its operation, while the energy reserve of electric batteries will decrease by about 2 times.
By the way, the air exhausted in the air motor has low temperature and can be used to cool the car interior in the hot season, that is, you get air conditioning almost for free, without unnecessary energy costs. But the heater, alas, will have to be made autonomous. But this is much better than an electric car - which has to spend energy on both heating and cooling.
By the way, glass-carbon fiber cylinders are quite safe - if damaged, they do not explode, only cracks appear in them through which air escapes.
To what only methods do not resort auto manufacturers in order to attract the attention of consumers. The shopper is bewitched by fashionable futuristic designs, unprecedented security measures, greener engines, and so on and so forth.
Personally, I am not very touched by the latest delights of various design studios - even more: for me, the car has been and will remain an inanimate piece of metal and plastic, and all the attempts of marketers to tell me how high my self-esteem should rush into the sky after buying “our newest model"There is nothing but a concussion of the air. Well, at least for me personally.
More exciting to me, as a car owner, is the issue of economy and survivability. Fuel costs far from three kopecks, besides, in the vastness of the "great and mighty" there are too many followers of Vasily Alibabaevich from "Gentlemen of Fortune". Auto manufacturers have been trying to switch to the use of alternative fuels for a long time. In the US, electric cars have taken a fairly strong position, but not everyone can afford to buy such a machine - it's very expensive. Now, if budget-class cars were made electric ...
We set an interesting goal French manufacturers PSA Peugeot Citroen, they initiated an interesting program to reduce fuel consumption. This group of auto manufacturers is developing a hybrid power plant which could spend only two liters of fuel per hundred kilometers. The company's engineers already have something to show - today's developments make it possible to save up to 45% of fuel compared to an ordinary internal combustion engine: even with such indicators of two liters per hundred, it is not yet possible to fit in, but by 2020 they promise to conquer this milestone.
The statements are quite bold and interesting, but it would be more interesting to take a closer look at this hybrid and no less economical installation. The system is called Hybrid Air and as it becomes clear from its name, in addition to traditional fuel, it uses the energy of air, compressed air.
The Hybrid Air concept is not so complicated and is a hybrid of three cylinder engine internal combustion and hydraulic motor- pump. Two cylinders are installed as alternative fuel tanks in the central part of the car and under the trunk space: the larger one is for low pressure; and the one that is smaller, respectively, for the high. The acceleration of the car will take place on the internal combustion engine, after a speed increase of 70 km / h, the hydraulic engine is turned on. Through this same hydraulic motor and ingenious planetary transmission, the energy of compressed air will be converted into rotational motion of the wheels. In addition, an energy recovery system is also provided on such a car - during braking, the hydraulic motor acts as a pump and pumps air into a low-pressure cylinder - that is, such a desired energy will not be wasted.
According to the company's engineers, a car with hybrid plant Hybrid Air, even despite the greater mass by 100 kg compared to a traditional engine, will have fuel economy indicators of at least 45%, and this despite the fact that the refinements in this field of engine building are far from complete.
Hybrid systems are expected to be the first to be used in Citroen hatchbacks C3 and Peugeot 208, and it will be possible to ride on the “air” already in 2016, and French managers see Russia and China as the main markets for cars with the Hybrid Air hybrid.
Sometimes you need to have a low-power engine on hand that converts the energy of burning fuel into mechanical energy. As a right, such engines have a very difficult assembly, and if you buy a ready-made one, then you need to say goodbye to a tidy sum from your wallet. Today we will consider in detail the design and self-assembly one of these engines. But our engine will work a little differently, on compressed air. The scope of its application is very large (models of ships, cars, if supplemented with a current generator, you can assemble a small power plant, etc.).Let's begin to consider each part of such an air engine separately. This engine capable of giving from 500 to 1000 revolutions per minute and, thanks to the use of a flywheel, has decent power. The supply of compressed air in the resonator is enough for 20 minutes continuous work engine, but you can also increase the operating time if you use car wheel. This engine can also be operated with steam. The principle of operation is as follows - a cylinder with a prism soldered to one of its sides has a hole in its upper part, which passes and swings through the prism together with the axis fixed in it in the bearing of the rack.
Two holes are made to the right and left of the bearing, one for air inlet from the tank into the cylinder, the second for exhaust air. The first position of the engine shows the moment of air intake (the hole in the cylinder coincides with the right hole in the rack). The air from the reservoir entering the cylinder cavity presses on the piston and pushes it down. The movement of the piston through the connecting rod is transmitted to the flywheel, which, turning, brings the cylinder out of its extreme right position and continues to rotate. The cylinder assumes a vertical position and at this moment the air inlet stops, since the holes of the cylinder and the rack do not match.
Thanks to the inertia of the flywheel, the movement continues and the cylinder moves to the leftmost position. The hole of the cylinder coincides with the left hole in the rack and through this hole the exhaust air is pushed out. And the cycle repeats over and over again.
Air engine parts
CYLINDER - made of brass, copper or steel tube with a diameter of 10 - 12 mm,. As a cylinder, you can use a brass sleeve of a suitable caliber rifle cartridge. The tube must have smooth inner walls. A prism cut from a piece of iron should be soldered onto the cylinder, in which a screw with a nut (swing axis) is tightly fixed, above the screw, at a distance of 10 mm from its axis, a hole 2 mm in diameter is drilled through the prism into the cylinder for air inlet and outlet.
ROD - cut out of a brass plate 2 mm thick. one end of the connecting rod is an extension in which a hole with a diameter of 3 mm is drilled for the crank pin. The other end of the connecting rod is designed to be soldered into the piston. Connecting rod length 30 mm.
PISTON - cast from lead directly in the cylinder. For this in tin can pour dry river sand. Then we insert the tube prepared for the cylinder into the sand, leaving a protrusion of 12 mm outside. To destroy moisture, a jar of sand and a cylinder must be heated in an oven or on a gas stove. Now you need to melt the lead into the cylinder and immediately you need to immerse the connecting rod there. The connecting rod must be installed exactly in the center of the piston. When the casting has cooled, the cylinder is removed from the can of sand and the finished piston is pushed out of it. We smooth out all irregularities with a small file.
ENGINE RACKS - must be made according to the dimensions indicated in the photo. We make it from 3 mm iron or brass. The height of the main drain is 100 mm. In the upper part of the main rack, a hole with a diameter of 3 mm is drilled along the central center line, which serves as a bearing for the swing axis of the cylinder. The two uppermost holes with a diameter of 2 mm are drilled along a circle with a radius of 10 mm drawn from the center of the swing axis bearing. These holes are located on either side of the rack centerline at a distance of 5 mm from it. Through one of these holes, air enters the cylinder, through the other it is pushed out of the cylinder. The entire structure of the air engine is assembled on the main rack, which is made of wood with a thickness of about 5 cm.
FLYWHEEL - you can pick up ready-made or cast from lead (used to produce cars with inertial engine, there is the flywheel we need). If you still decide to cast it from lead, then do not forget to install a shaft (axle) with a diameter of 5 mm in the center of the mold. The dimensions of the flywheel are also indicated in the figure. There is a thread on one end of the shaft for fastening the crank.
CRANK - cut out of iron or brass with a thickness of 3 mm according to the drawing. The crank pin can be made of steel wire with a diameter of 3 mm and soldered into the crank hole.
CYLINDER CAP - we manufacture 2 mm brass and after casting the piston is soldered to the top of the cylinder. After assembling all the parts of the engine, we assemble it. When soldering brass and steel, you should use a powerful Soviet soldering iron and saline acid for strong soldering. The tank in my design is used from paint, rubber tubes. My engine is assembled a little differently, I changed the dimensions, but the principle of operation is the same. The engine used to work for me for hours, it was connected to homemade generator alternating current. Such an engine may be of particular interest to modellers. Use the engine where you see fit and that's it for today. Good luck with the build - AKA
Discuss the article AIR ENGINE
These vehicles have no fuel tanks, no batteries, no solar panels. These machines do not need either hydrogen, or diesel fuel, or gasoline. Reliability? Yes, there is almost nothing to break. But who today believes in an ideal solution?
Australia's first compressed air vehicle to enter the real world commercial exploitation, recently took up his duties in Melbourne.
The device was built by the Australian company Engineair engineer Angelo Di Pietro (Angelo Di Pietro).
The main problem that the inventor thought about was to reduce the mass of the engine while maintaining high power and completeness of use of energy of compressed air.
There are no cylinders and pistons here, and there is no triangular rotor, like the Wankel engine, or turbine wheel with spatulas.
Instead, a ring rotates in the motor housing. From the inside, it rests on two rollers eccentrically mounted on a shaft.
Sectional view of the engine of the Australian Italian Di Pietro (photo from gizmo.com.au).
6 separate variable volumes in this expansion machine cut off the movable semi-circular petals installed in the sections of the body.
There is also an air distribution system in the chambers. That's almost all.
By the way, the Di Pietro engine produces maximum torque immediately - even when stationary and spins up to quite decent revolutions, so a special transmission with variable gear ratio he doesn't need to.
So you can arrange the drive of a car according to the Di Pietro system. Two rotary air motors, one per wheel. And no transmission (illustration from gizmo.com.au).
Well, the simplicity of design, small size and low weight are another plus in the treasury of the whole idea.
What is the result? Here, for example, is a pneumatic car from Engineair, which is being tested in the warehouse of one of the grocery stores in the Australian capital.
The carrying capacity of this trolley is 500 kilograms. The volume of air cylinders is 105 liters. Mileage on one gas station - 16 kilometers. In this case, refueling takes a few minutes. While charging a similar electric car from the network would take hours.
The strange connection between the piston and the crankshaft in the French air motor allows the piston to stop at dead center while maintaining uniform rotation of the motor output shaft (illustration from mdi.lu).
It is logical to imagine how similar installation more power can be mounted on a small passenger car intended for movement mainly within the city.
It needs to be mentioned here important advantage pneumatic cars before electric cars, which are also tipped to be a promising means of transportation in a city that cares about clean air.
Batteries, even simple lead-acid ones, are more expensive than cylinders and are pollutants environment after resource depletion. Batteries are heavy, and so are electric motors. Which increases the energy consumption of the machine.
True, when air is compressed in the compressors of the “pneumatic filling station”, it heats up, and this heat heats up the atmosphere to no avail. This is a minus in terms of overall costs and energy consumption (for the same fossil fuel) for refueling such machines.
But still, in many situations (for metropolitan centers) it is better to come to terms with this, getting a zero-emission car in return at a reasonable price.
Pneumatic CityCATs Taxi and MiniCATs from Motor Development International (photo from mdi.lu).
Therefore, Di Pietro has reason to believe that it is he who will be able to bring air-powered cars into a “large orbit”.
Recall that the idea of using compressed air as an energy carrier for vehicle- very old.
One such patent was issued in Great Britain in 1799. And, as A.V. Moravsky reports in the book “History of the Car”, at the end of the 19th century, with the creation of reliable cylinders designed for high pressure, such cars gained some distribution in Europe and the USA - as intra-factory technological transport and even as urban trucks.
However, the energy intensity of compressed air, even if the pressure was brought up to 300 atmospheres, was low. Gasoline looked better in every possible way, and hardly anyone thought about air pollution then.
It took another hundred plus years for a new generation of inventors to bring pneumatic vehicles back to the road.
In this new "air" wave, the Australian engineer was not the first. For example, we have already talked about the Frenchman Guy Negre.
His company - Motor Development International, engaged in the development and promotion of the original Negre air motor and cars based on it - is still full of bright hopes, but about serial production so far nothing has been heard, although a lot of prototypes have been made.
The design of its engine (and, in fact, it is piston motor), we note, is constantly undergoing changes. In particular, it should be noted an interesting mechanism for connecting the piston and the crankshaft, which allows the piston to stop for a while at a dead center and then break down with acceleration - with uniform rotation of the output shaft.
power unit CATs machines (illustration from mdi.lu).
This “stammer” is needed in order to have time to supply more air to the cylinder and then make fuller use of its expansion.
By the way, another sensible idea was proposed by the French.
Negre's cars can be refueled not only directly from the compressor station, but also from the outlet - like electric cars.
In this case, the generator mounted on the air motor turns into an electric motor, and the air motor itself into a compressor.
