The Dynamic Modeling And Simulation Of The Helicopter Gearbox Isolation System With Fluide Lastomer Isolator

Rotor is the main vibration source of helicopter, how to reduce the vibration influence onhelicopter caused by rotor has always been an important project in helicopter dynamic researching.This dissertation studied a helicopter gearbox isolation system with fluid elastomer isolator. Bycombining fluid elastomer isolator with6degree of freedom isolation system, a considerable isolatingeffect on the vibration load of the hub was reached.Firstly, analysis on the dynamic feature of mechanical dynamic anti-vibration isolator and fluidelastomer isolator was made, the isolating frequency of the isolator and transfer function was derivedand the equivalent mechanical model for fluid elastomer isolator and mechanical dynamic anti-vibration isolator was established. Referring to6degree of freedom isolating theory of Stewartplatform, a kind of6freedom degree isolating system with fluid elastomer isolator was built.Dynamic equation for the system using Newton Euler method was formulated and the couplingcharacteristic of the system was analyzed. The results indicated that when the parameters of6fluidelastomer isolators are the same, the system’s coupling characteristics depends on its configurationand the dynamic features of fluid elastomer isolator has no influence on system couplingcharacteristics. On this basis, a symmetric6rod vibration isolation platform possessing fluidelastomer isolator with relatively weak coupling was selected to simulate the gearbox system ofhelicopter. Further, the relationship between parameters of this system configuration and stiffnessmatrix has been analyzed and the conclusion acquired would direct stiffness design for the system. Atlast, modal analysis, frequency domain analysis, time domain analysis and parameter sensitivityanalysis was carried out on the helicopter gearbox isolation system. The result made it clear that thisisolation system has same anti-vibration frequency in6directions, which can effectively isolate thevibration load of the rotor hub.