Dynamics of rotors supported by magnetic bearings

Аuthors

Leontiev M. K.^1*, Davydov A. V.^1**, Degtiarev S. A.^2***

1. Moscow Aviation Institute (National Research University), 4, Volokolamskoe shosse, Moscow, А-80, GSP-3, 125993, Russia
2. Scientific and technical centre of rotor dynamic «Alfa-Tranzit», 1, Leningradskaya str., Khimky, Moscow region, 141400, Russia

*e-mail: lemk@alfatran.com
**e-mail: davidovarc@gmail.com
***e-mail: degs@alfatran.com

Abstract

The active magnetic bearings have many advantages compared to traditional bearing designs. However they require auxiliary bearings to prevent damages of AMD when the event power or a control loop failure. The design parameters of such supports have a significant influence on the behaviour of the rotor in dropdown situation. In this paper, common equations of rotor dynamics systems in nonlinear and nonstationary statement are studied. Nonlinear model of AMB, clearance and rolling bearing models are considering. Simulation results of rotor dropdown on auxiliary bearings and subsequent runout are shown with different types of auxiliary bearings. Shown, that in some cases, the rotor can perform dangerous motion for the construction backward whirl and/ or rolling motion.

Keywords:

active magnetic bearings, rotor dynamics, rolling bearing, bushed bearing, clearance, rolling motion, backward whirl.