Optimal sizing and comparison of permanent magnet thrust bearings

The aim of this paper is to study different permanent magnet bearings geometries based on permanent magnet rings with a minimum volume of permanent magnet for a given load. Simple and general scaling laws are proposed for each bearing geometry to predict its behavior. These scaling laws allow a fast sizing of those geometries, as a function of the number of permanent magnet rings, the load reference, the air gap and the remanent flux density. Those scaling laws are derived for optimized topologies without any constraint on the geometrical parameters, as well as for optimized geometries with a constraint on the permanent magnet dimensions. For both cases, scaling laws for the thrust bearing stiffness are also proposed