Abstract: Through summarizing the characteristic of axial displacement fault about centrifugal compressor and analyzing the mechanical performance of tilting-pad thrust bearing, a method of on-line axial displacement fault prognosis and diagnosis is presented, and axial fault displacement self-recovering is realized by experimental study. This type of fault has little indication before coming and the fracture of oil film between thrust disk and tilting pad mainly contributes to this breakdown. Usually the fracture is caused by the contamination of oil or decrease of oil supply pressure which result in losing of load bearing capacity of oil film. Also the increase of axial force caused by fluctuation of operation condition can result in the oil film fracture. Either of the causes can lead to tilting pad abrasion and emergency shutdown of machine. The method monitors the stiffness of oil film and identifies the cause of axial displacement increasing. By introducing the mechanism of axial displacement fault self-recovering and taking the axial displacement as the control parameter, the axial forces on rotor is controlled on-line and the minimum oil film thickness is ensured in real time. Experimental study indicates that the mechanism can realize axial fault self-recovering effectively.

Key words: Axial displacement, Centrifugal compressor, Fault self-recovery, Thrust bearing