Development of Magnetic Bearing Wheel (MBW) with Inclined Magnetic Poles

2nd Report, Analysis of Disturbance Factors and Motion of MBW

Abstract

A Magnetic Bearing Wheel (MBW) with inclined magnetic poles is under development. This paper deals with the analysis of disturbance factors and motion of MBW. In general, disturbance factors of a magnetic bearing is limited to rotor imbalance, and motion of the magnetic bearing is discussed under the action of synchronous disturbance force/moment caused by the imbalance. This imbalance is defined by the radial shift (static imbalance) and tilt (dynamic imbalance) of sensor detection surface against the principal inertial axis of rotor. However, besides the imbalance, there are actually other disturbance factors such as the radial shift and tilt of rotor core surface similar to sensor detection surface, and the distortion of those surfaces so that MBW generates synchronous and harmonic disturbances. In this paper, all disturbance factors of MBW is formulated, and the relation between each factor and disturbance force/moment is clarified. Moreover, it is clarified that there are forward and backward components to the direction of rotor spin in radial harmonic disturbances.