Structure Design and Optimization of Thrust Magnetic Bearing for the High-speed Motor

Magnetic bearings are oil-free bearings that are widely employed in rotating machineries such as high-speed motors in order to eliminate lubrication systems, reduce wear, increase efficiency and mechanical service life. Based on a high-speed motor with a power of 5 kW and a maximum speed of 60 000 rpm, active thrust magnetic bearings are designed to match with the high-speed motor considering the limited space. On the premise that the maximum thrust is determined, a functional relationship between thrust provided by TMB and the structure parameters of TMB, mainly including magnetic ring area and the cross sectional area of coil cavity, built by magnetic circuit method, combined with the size of the available space in the high-speed motor, we find the suitable structural parameters through a new optimization algorithm. The finite element software, Maxwell is used to verify the feasibility and reliability of the design. It provides a reference for the design of TMB with minimum volume in the high speed motor. This paper provides the design scheme of the minimum volume of TMB as a reference.