Analysis on the Performances of Misaligned Journal Bearings using Full-Scale Test Rig and Conjugate Heat Transfer Method

Abstract

Misalignment effects increase the risk of scratch or seizure failure for the journal bearings-rotor system. To investigate the performances of misaligned journal bearings, a full-scale journal bearings-rotor system test rig is designed and journal orbits are tested under different speeds. Then, a THD lubrication model is established to simulate lubrication performances under different misalignment conditions. The results show that for a misaligned journal bearings-rotor system, the center of the orbits of the bearing closing to coupling is fixed around the coupling. The orbits center of the bearing far away coupling is floating gradually with an increasing speed. The vibration amplitude of bearing closing to coupling is larger than that of bearing far away from the coupling. When the minimum oil film thickness is decreasing, the maximum film temperature is increasing except for the bearing closing to coupling. For different misalignment directions, maximum film temperature is determined by the position of the high pressure zone and high temperature zone.