Effects of axial offset and deflection on load-bearing characteristics of the permanent magnet bearing

Abstract

The permanent magnet bearing (PMB) has the advantage of non-contact support, which is used to reduce mechanical friction and wear of journal bearings. The effect of translation or deflection between the magnets on the load-bearing characteristics has been studied separately rather than simultaneously, causing the load-bearing characteristics of the device in use to deviate significantly from those intended. In this study, the magnetic force, magnetic moment and stiffness are used to evaluate the load-bearing characteristics of the PMB. The load-bearing characteristics in service are investigated using numerical simulation, taking into account the coupling of axial offset and deflection. The results showed that the alignment-capable magnetic moment appears only in single-sided axial offsets, and its threshold changed by 0.14 times the deflection angle, both were positively correlated with each other. Under the coupling of axial offset and deflection, there is a significant error of up to 200 % between the actual and design values. In addition, the axial force and axial stiffness were affected significantly by axial offset but were insensitive to the deflection angle. Translation and deflection are critical factors affecting load-bearing characteristics. This study helps to narrow the gap between the design performance and service performance of the PMB, avoid magnets collisions, and reduce the possibility of device failure.