Vibration reduction in a hollow-shaft rotor using flexibly-mounted internal-stator magnetic bearings

Abstract

A topology composed of a hollow-shaft rotor on rolling element bearings coupled with internal-stator magnetic bearings mounted on independently supported flexible shafts is considered for the purposes of vibration reduction. Details of a bespoke test rig constructed to assess this topology are presented. The rig makes use of custom-designed internal-stator magnetic bearings fabricated from Soft Magnetic Composite material. Results from standard numerical analysis of the rig are given to demonstrate the expected behaviour of the system, with a particular focus on its potential to reduce synchronous vibration seen in the rotor while passing critical speeds. These behaviours are then confirmed via a series of experimental tests. These results show that the proposed topology can be used effectively to alter the system vibration behaviour.

Keywords

• magnetic bearings
• rotor dynamics
• control systems
• homopolar
• soft magnetic composite