Vibration Analysis and Active Control of Flexible-Shell-Structured Rotor Supported by Magnetic Bearings

Abstract

Modal control of magnetic bearings is applied to a shell-structured rotor to reduce the structural vibration. It is intended that the rotor be light and have a wide supporting region of magnetic flux ; hence it is made of a flexible shell structure. These structures are apt to produce shell vibrations, in addition to bending vibrations of the rotating shaft. To improve the damping property of the structure, a new control scheme for a magnetic bearing is introduced. Each magnet is controlled individually, leading to favorable structural damping, which contrasts with the traditional controller where a pair of magnets is controlled in a push-pull operation. The modal control technique is applied to the proposed magnetic bearings. The results obtained indicate a good damping property.