An Analysis of Vibration Characteristics of a Rotor System with Coupling Faults of Bearing Looseness and Bearing Pedestal Looseness

Abstract

Frequent disassembly of bearings leads to wear of the bearing pedestal hole, and a loose bearing impacts the bearing pedestal, causing it to loosen. To identify this type of malfunction, a dynamic model of the rotor system with the coupling faults of bearing looseness and bearing pedestal looseness was established based on the concentrated mass method of the rotor system. Also, the mapping relationship between the collision force and the vibration peak value was established and the coupling mechanism was described. The results indicate that when the coupling fault existed, the new frequency components were generated in the spectrum, and the frequency amplitude was positively correlated with the amount of looseness. Meanwhile, the increase in looseness would cause an increase in the amplitude of the fault characteristic frequency. Identifying the characteristic frequency and amplitude of looseness faults plays an important role in monitoring faults in rotor systems.