Conceptual Design And Mechanical Analysis On Manipulating Mechanism Of High-Speed Coaxial Helicopter

Helicopter has good flight performance like vertical take-off and landing, hover and flight at low altitude. It is widely used both in military and civilian fields. Compared with fixed-wing air-crafts, helicopter has lower speed, smaller range and larger vibration and noise because of the shock wave and stall of the blade. But the aircraft is likely to be restricted by the landing site, whose characteristic makes the helicopter unable to be replaced by other vehicles. That is the reason why helicopter has been a research object of aircraft enthusiasts; Meanwhile, the helicopters can be equipped with army to increase the defense force; in order to expend the application filed, the helicopter with higher mobility, higher speed and farther range is needed urgently. According to the application demands of high-speed helicopter and the importance and urgency of high-speed helicopter development, a composite type high-speed coaxial helicopter with a propulsion propeller layout is proposed in this thesis.Firstly, the performance indicators of high-speed coaxial helicopter is formulated according to the design objectives and requirements. The conceptual parameters of the high-speed coaxial helicopter is determined through analysis and calculation based on the design theory of helicopter, and the parameters of high-speed helicopter and coaxial helicopter from home and abroad. The engine is selected according to the technical demand and supply market of the high-speed coaxial helicopter engine. The foundation is laid for the further design of helicopter. Secondly, according to the interface of engine and the conceptual parameters of helicopter, the main rotor reducer manipulating mechanism and the motor and reducer of the helicopter propulsion system are designed through the modular design method and mechanical design theory. And the parts of the high-speed coaxial helicopter’s transmission system and manipulating system are designed. Thirdly, based on the above work, the force on the main rotor manipulating mechanism is analyzed discretely in the environment of MATLAB and the key parts of the main rotor’s manipulating mechanism is simulated by ANSYS at the limited position of the swashplate mechanism, which are based on the basic size prototype according to the working principle of the main rotor’s manipulating mechanism. The foundation for the further optimization of helicopter is laid. At the same time, according to the working principle of main rotor’s manipulation and structure mechanism parts as well as the development and application of modern sensor, a series of measurement including the pitch, pitch link stress, rotor speed and azimuth is schemed and the hardware circuit is designed according to the requirement of sensors. Meanwhile, the sensor signal is demodulated into digital signal in accordance with the requirements of the sensor, and the hardware circuit is verified by the experiment according to the present conditions, and the feasibility testing scheme and the correctness of hardware circuit is ensured. In this thesis, the conceptual parameters of the high-speed coaxial helicopter is determined. The main parts of the transmission system and the manipulating system is designed detailed. The main rotor control statics is analyzed and the measurement scheme of the pitch, rotor blade hinge moment, rotor speed and azimuth is designed. However, there is still a lot of work to do on the development of high-speed coaxial helicopter in the future.