Rotor-Stator Contact in Polygonal Backup Bearings

(www.u-sim.de)

PHD thesis of Ulrich Simon to become a Dr.-Ing. from Technical University of Braunschweig, Germany, 2001, at the Institute of Engineering Mechanics, Director: Prof. Dr. E. Brommundt.

Abstract

Backup bearings are used to limit the radial displacement of rotors.  These bearings are active at emergency situations only.  Common bearings are round shaped.  In this type friction between the rotor and the bearing can cause servere self exited movements, which are charactericed by high speed counterwirl movements of the rotor center leading to great unbalances.  Using polygonal backup bearings instead the speed and unbalances of the rotor movements can be reduced.

A three sided backup bearing shows advantages vs. a common round shaped bearing.

Keywords: 

Retainer Bearing, Auxiliary Bearing, Emergency Bearing, Backup Bearing, Touchdown Bearing, Rotor-Stator Rub, Backward Whirl, Reverse Whirl, Inverse Precession, Full Reverse Precession Rub, Dry Friction Whip, Dry Friction Counter Whirl.