Reduction of Stator Vibration Acceleration Using One-Axis Actively Positioned Single-Drive Bearingless Motor

Bearingless motors have several advantages, and their designs and characteristics have been studied. However, stator vibration acceleration has not yet been reported experimentally. This study investigated stator vibration reduction using a small permanent magnet (PM) bearingless motor with repulsive passive magnetic bearings. The dynamic modeling of motors with ball bearings and repulsive passive magnetic bearings was introduced to examine the difference in the vibrations via MATLAB/Simulink simulation. Two test machines were used as part of the experimental setup: (a) bearingless motors with repulsive passive magnetic bearings, and (b) a motor with ball bearings. The experimental results confirmed that the stator vibration acceleration levels of the bearingless motor were significantly reduced, by up to 98.7%, compared with those of the motor with ball bearings.