Permanent magnet bearings: Analysis of plane and axisymmetric V-shaped element design

Abstract

Applications of permanent magnets bearings have gained a new interest thanks to the development of rare earth materials, characterised by residual magnetic induction greater than 1 T. The present paper proposes a new geometry for permanent magnets bearings with V-shaped elements, both for a plane slide and for cylindrical bearings. The aim of this geometry is to give new possibilities to the application of these bearing systems, by reducing its inherent instability. A design method, involving Finite Elements and Magnetic Field Integral Equations analyses, is also described for defining the most suitable V-opening angle and the two magnetisation directions. These parameters can be varied in order to reduce the unstable force in the coupling, and to reach the desired force and stiffness in the stable direction. The design is founded on the evaluation of four 'geometric' vectors, that depend on the geometry of the elements. Some results are reported for a reference geometry for both the slide and the cylindrical bearings.