Abstract
In this paper, a main gearbox using an encased differential gear train to achieve coaxial contra-rotating is considered, and a dynamic modeling method of the rotor-stator coupling system of the gearbox based on box model updating is introduced. The transverse torsional dynamic model of the gear transmission subsystem is established based on the lumped parameter method. The finite element model of the box is updated according to the modal test data, and the reduced dynamic parameters of the box are obtained. According to the displacement coordination condition, the dynamic model of the rotor-stator system of the gearbox is established. The vibration response of the transmission components with or without the coupling box is calculated by numerical integration, and the response of the box caused by the dynamic support reaction force is analyzed by the finite element method. The results show that the vibration peak and fluctuation range of the transmission parts with coupling box are smaller than those without coupling box. The box response at the support of the input bevel gear pair is large, while that at the support of the output shaft is small.