High Specific Load Capacity Magnetic Bearings

The term `specific load capacity (SLC)´ is defined as the ratio between the maximum achievable force and the total self-weight of a magnetic bearing. Conventional radial magnetic bearings typically have a specific load capacity in the order of 40:1. In this paper we describe a new class of passive and active magnetic bearings that comprise a large number of parallel airgaps. The motivation of moving towards a radical change of design is to deliver magnetic bearings that have SLC significantly higher than 40:1. The parameters affecting the SLC of both passive and active variants have been investigated across the whole design space by finite element analysis (FEA) and analytical methods respectively. The mechanical stability of the designs is then assessed using a finite element code written in MATLAB.