Fault diagnosis of tilting-pad type fluid film bearings in high-speed rotating machinery

Abstract

Of all fluid film bearing types, tilting pad bearings offer the optimal rotordynamic stability due to their excellent stiffness and damping characteristics. Due to the reduction in cross-coupling stiffness, tilting pad bearings are ideal for use in high-speed and high-load turbomachineryapplications, such as industrial compressors and steam/gas turbines. In this investigation, we propose the method to diagnose the main failure mode of tilting pad journal bearings such as babbitt metal wear and pivot wear in bearing pads. Various experimental cases for bearing wearwere precisely implemented through a high-speed rotating test rig operating at 10,200 rpm. The vibration and temperature data were obtained through a condition monitoring system and various features from shaft vibration, bearing metal and lubrication temperature data were extracted for the fault diagnosis. In this study, we have shown that even defects due to the abrasive wear of fluid film bearings including general rotor faults, such as unbalance, misalignment and rubbing, can be accurately diagnosed.