Utilizing a radial magnetic bearing to stabilize self-excited vibrations in a rotor-oil film bearing system

Oil film bearings have higher load capacity and larger damping than ball bearings. Therefore, the rotors of large turbomachines are usually supported by oil film bearings. However, at high rotational speeds, the swirling flow of the lubricant destabilizes the rotor system and induces self-excited vibrations such as oil whip and oil whirl. Since these vibrations limit the operational speed and reliability, a method for eliminating them and increasing the operational range is necessary. We propose a method for stabilizing these self-excited vibrations by using a radial magnetic bearing (RMB) to cancel the force due to the cross-coupled stiffness described in the Bently-Muszynska model. The purpose of this study is to experimentally examine the relationship between the gain of the controller and the stability.