Rotor System Oscillations under the Rotor Rotation Inside Floating Elements

Abstract

Rotor system oscillations are considered for the rotation of the rotor inside lightweight moving elements (for example, inside floating seal rings, and hydrostatic bearings). In this case, the ring runs around the rotor in a direct precession mode (hula-hoop type of oscillations). The oscillations of the rotor-floating ring system are studied taking into account hydrodynamic forces in the gap and contact forces of dry friction. A solution is obtained in analytical form. It is shown that the ring precession speed under the running-around is close to its own frequency at a given rotation speed. Trajectories are plotted for the motion of the ring.