Dynamic analysis of multi-stage planetary reducer in TBM cutter head driving system

The failure of reducer in tunnel boring machine (TBM) cutter head driving system has not been properly solved owing to the complex influence factors. In this paper, a dynamic model of multi-stage planetary reducer is established and a simulation model of direct torque control (DTC) system is developed to simulate the actual driving torque. By taking account of motor operating characters and nonlinear factors such as time-varying mesh stiffness and transmission error, inherent property and dynamic response of multi-stage planetary reducer are analyzed. Inherent property shows the vibration modes can be classified into the rigid motion mode, rotational vibration mode and planet vibration mode. Dynamic responses show all the vibrations appear in the low frequency domain and approach to the low-order natural frequency. The vibration amplitude of 2th-stage component is the smallest among all the three stages. The modal properties and dynamic response characteristics analyzed in this paper provide effective support for the dynamic design of multi-stage planetary reducer in TBM cutter head driving system.