Research Of Transmission Mechanism And Swashplate Mechanism For A High-Speed Coaxial Helicopter

Helicopter has been widely used both in military and civilian fields,as their special flightperformance,which can hover and vertical take-off and landing. Helicopter’s speed is lowerand range is smaller, while compared with fixed-wing aircrafts，under the restriction ofadvancing blade shock wave and retreating blade stall.It’s a common dream for helicopterdesigners to design a helicopter which performance better in speed, mobility and range. Thecompound stytle of coaxial rigidity rotor,as which eliminate the retreating blade stall withhigh angle of incidence,has been a new approach to raise the speed of helicopters.In this paper,a high-speed coaxial helicopter has been designed according the requirements and potentialneeds in military and civilian fields.The technical requirements in using coaxial helicopters has been given according to therequirements in military and civilian fields. General parameters has been confirmed bycalculation and analysis under the foundation of consideration of the parameters of coaxialhelicopters’ and high-speed helicopters’ form domestic and overseas. And engine model hasbeen selected according to the performance requirements and supply of the market. Thusmade guide for the design of helicopter.The transmission mechanisms, which was made up by overrunning clutch module, mainrotor transmission mechanisms module and propeller transmission mechanisms modular, hasbeen designed in the CAD environment by modular approach. The swashplate mechanisms ofmain rotors and propeller have been designed. The main components and parts of helicopterhave been designed.Expound the working principle of swashplate mechanisms both main rotor’s andpropeller’s, simplified the mechanisms, and draw the schematic diagram of mechanisms.Calculate the mechanism’s degrees of freedom,according to the Kutzbach-Grüblerformula.Kinematics model of swashplate mechanisms has been established layeredly by theenclosing method,and kinematics model of propeller mechanisms has been established bynumerical method, the forward and inverse kinematics functions for both models has beenderived. It made a theory foundation for the helicopter control.The kinematics model has been setted up in matlab environment, according to thekinematics functions. The motion property of swashplate mechanisms has been discussed, therelationship of the swashplate mechanisms’ motion and helicopter’s control channel has beenreserched. And the collective pitch channel and yaw channel have been decoupled. Got thedata of swashplate mechanisms in different motion, while the static and dynamic experimentequipments for kinematics have been designed. The validity and effectiveness has beenconfirmed by compareation between simulation and experiments.