Helicopter History - Early
Since ancient times, people wanted to go up in the air like a bird. Great way to this dream - the myth of Icarus flying to the sun and the fairy tales of the flying carpet to fly supersonic modern airliners and spacecraft. The idea of establishing a helicopter - one of the oldest in the history of flight. This is confirmed by the materials found in the archives of the Library of Milan in the middle of the XIX century. Among them are preserved paintings, made by the hand of the famous Italian scientist and artist Leonardo da Vinci in 1475 in these figures and captions expressed the idea of using the Archimedes screw in the construction of aircraft. Leonardo da Vinci plans to carry out a vertical take-off of its models with a screw rotating in a horizontal plane. But his project was far from practical implementation.
The first experience of construction of a working helicopter model was implemented in 1754, by the great Russian scientist Mikhail Lomonosov. Catching up on the study of the upper atmosphere, the scientist constructed a small aircraft capable of lifting up into the air meteorological instruments. About the design features of this device an idea is gained from the drawing made by MV Lomonosov. In a small lightweight body was placed clock spring which gears the system was connected to two concentric ridges with attachments to them two propellers, one above the other.
The researchers suggest that, working on the creation of this unit, MV Lomonosov took into account the torque caused by the rotation of the bearing system and counterbalanced by its location on the same axis of two screws rotating in opposite directions. This arrangement of screws later became known as coaxial and is widely used in the practice of helicopter industry. In the drawings Lomonosov, built a working model of the machine, which he demonstrated July 1, 1754 the members of the Russian Academy of Sciences. "Right honorable Adviser Lomonosov showed he invented a machine called them aerodynamic (ie vozduhobezhnoy) - was recorded in the minutes. - The aircraft was suspended on the cord, stretched over two blocks, and hold weights balance, suspended from the opposite end. As soon as the mainspring, the aircraft climbed to a height and, therefore, promised to achieve the desired effect. But this action, according to the inventor's judgment, will increase even more if the spring force will be increased, and if you increase the distance between one or the other pair of wings, and the box in which lies the spring, will be made to reduce the weight of the tree. This he (Lomonosov) promised to take care of."
In those years for the screw driving device of vehicles, including vessels, generally was not known or used. Lomonosov was the first who attempted to lift into the air the aircraft, which was at that time a great achievement. Of course, to build a model of a large size due to the lack of a powerful and reliable engine was impossible with insufficient level of technological development in those years. Many inventors and craftsmen in different countries tried to build flying machines with flapping wings - ornithopters, that is, use the solution suggested by the nature itself. However, their attempts were unsuccessful, and still has not built any ptitsekryloy machine that could hold well in the air and had basic flight performance. The technical problem of creating such a machine proved extremely difficult. Numerous failures in this area turned to the idea of the inventors of devices with rotors that are driven by motors.
In the second half of the XIX century, technological progress has created a favorable environment for researchers and inventors, working in the field of aeronautics and aviation. Creating a machine that can take to the air, it became real only after the engine when the technology has reached a relatively high level. In 1869, a well-known Russian electrical engineer AN Lodygin designed the first "elektrolyet", which had two propellers. One - the carrier to create a vertical thrust, the other - for drawing a horizontal thrust. To rotate the screw the designer proposed a special motor capacity of 300 liters. from. But this project was not implemented due to lack of funds. Great contribution to the study of works of propellers for helicopters made an Academician MA Rykachev. Back in the early 1870s he built a special device for the study of traction screws rotating in a horizontal plane. At the end of the XIX century in Russia came the first theoretical work on propellers and aerodynamics. Their authors were well-known Russian scientists SK Drzewiecki, Mendeleev, NE Zhukovsky, Chaplygin, Tsiolkovsky and others. The results of the first works on helicopters in one country are not well known in other countries, and is often the development of new ideas in this area went independently and in parallel.
In the beginning of 1907 Russian military engineer K. Antonov began drafting the helicopter, which was built three years later. Two screw wheels consisted of separate aluminum plates, triangular blade, fastened two large hoops. Screw blades can rotate around their longitudinal axes. By changing the desired angle of attack of the blades was formed a kind of screw wheels parachute. Small propeller helicopter had to create traction, providing horizontal movement. The device was equipped with a horizontal stabilizer and the wheel turning. The gondola is enclosed by a lattice with a handrail. Screw the wheels driven by a petrol engine capacity of 30-35 liters. c., simultaneously transmitting motion by means of special screws and gear shaft. The device was installed on the truck, which had three rotatable wheels. When testing the device due to the low power of the engine could not develop the necessary lift and off the ground.
Built in 1908 by a student of the Kiev Polytechnic Institute, Igor Sikorsky's helicopter had two bladed propeller, fortified on the vertical axis at a distance from one another. Screws driven by three-cylinder petrol engine capacity of 12 liters. Tests have shown that the engine power was not sufficient for lifting the machine. Despite the setback, Sikorsky in the spring 1910 built a second helicopter. He had two screws and was equipped with a more powerful engine of 25 liters. The device weighed 180 kg. But the designer, who had not brought his work to the end of the helicopter, began working in the field of airplanes.
At the beginning of 1909 student of the Moscow Higher Technical School, and an active participant in the aeronautic circle, later academician, honored worker of science and technology BN Yuriev developed a draft of the original helicopter. In the middle part of the fuselage was placed a "Gnome" engine with a capacity of 70 liters for rotation of the two-blade propellers. The top - with a diameter of 9 m and the lower - 3 meters. In addition, the device had a tail rotor with rotating blades. To ensure the manageability and sustainability of a helicopter in flight was provided the so-called machine-skew, which allowed changing the angles of the rotor blades and thereby tilting the device in the desired direction. Helicopter was equipped with a chassis to run and stop the motor parachute in the case. The total weight of the unit is 315 kg.
At the end of 1909 Yuriev developed a second version of his helicopter. But they could not find a suitable motor, as the demand for power take-off was 50 liters. The only engine, which ess located in aeronautic circled at the Moscow Higher Technical School was "Anzani" capacity of 25-30 liters. Yuriev had to again alter the helicopter project, in order to be able to use a single engine. Only in early 1912 the helicopter "St. George" was built. It was a single-engine machine. The diameter of the two-bladed propeller was 8 m. Reactive time rotor designer offered to compensate by using the tail rotor mounted in the tail end of the farm. It was rotated prime mover via a special transfer mechanism. This arrangement entered the history of the modern helicopter industry as a classical scheme of single-rotor helicopter with tail (steering) screw. Due to the low engine power and the need to facilitate as much as possible the weight of the machine Yuriev had to abandon the installation of the machine and rotary-skew propeller blades. Nevertheless unit weighed 202.5 kg. In the spring of 1912 the helicopter was demonstrated at the 2nd International aeronautic exhibition in Moscow, and he was awarded a gold medal.
However, as he wrote to St. George, "I started experiments with this helicopter but had to stop, because there was a breakdown of the main shaft of the extremely uneven stroke three-cylinder four-stroke engines" Anzani ". Money for the continuation of work in the circle was not availible .... " Long before similar inventions abroad, BN Yuriev managed to create a machine-warp, to explore and develop the screws autorotation descent the problem of security apparatus in the event of engine stop. He also solved questions about the forward speed and duty helicopter.
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