The rotordynamic analysis of a high speed multistage centrifugal compressor supported on radial magnetic bearings, which has been running successfully in the field for 9000 hours to date, is presented. Iterations required to achieve an acceptable rotor configuration using magnetic bearings are discussed. The results of the rotor-bearing system on standard fluid film five shoe tilting pad journal bearings are compared to the dynamics of the rotor on magnetic bearings.
Correlation of the observed peak responses with those predicted on magnetic bearings is presented. The actual orbit plots and frequency plots during the coastdown of the rotor-bearing system on auxiliary ball bearings are discussed.