Dynamic Analysis For Helicopter Tail Rotor Transmission System

In the transmission system of the helicopter, it is very important to transmit power to the tail rotor. The key technique to improve the helicopter's capability is to accurately predict the dynamic response of the tail rotor. In this paper, a model of the transmission system is made through analyzing the characteristics of the structure. A reduced dynamic system for the power transmission process of the tail rotor can be gained by some assumption. The mechanical vibration theory can be used to derive the differential equation. Dynamic analysis of the tail rotor transmission can be carried out through the Matlab programming which solves the system's natural frequency and model.This paper introduces the transmission system of helicopter's tail rotor. A simulated system of tail transmission and its dynamic model are proposed. For the flexure vibration analysis, the level shafts are treated as a spring, and shafts are connected h each other by couplings. Because the coupling is heavier than the shaft, it is regarded as a mass point. In the same way, the gears of middle reducer and tail reducer are treated as mass points. A reduced dynamic model—mass and spring system is built. For the torsion vibration analysis, level shafts and tail shafts are simplified as springs, and the couplings and the gears as disks. The reduced dynamic model—disk and spring system is built. Therefore, the system's differential equation can be formulated. The transfer matrix method is used for the calculation of the flexure vibration. And Newton method is used to calculate the torsion vibration. The Matlab program is developed for the dynamic analysis of helicopter tail transmission.