Optimal strength design of a high-speed permanent magnet motor rotor based on multi-dimensional visualization

In a high-speed permanent magnet motor, the permanent magnet is usually not strong enough to bear the centrifugal force caused by high-speed rotation, so, a high strength and non-conductive metal sheath is needed to protect the permanent magnet material. For the structure of a solid cylinder permanent magnet rotor in the high speed permanent magnet motor, the stress condition of the rotor could be simplified as a plane stress state, and the analytical formula for the strength calculation of the cylindrical permanent magnet rotor with a non-magnetic metal sheath was derived by the displacement method in polar coordinate. On this basis, a multi-dimensional visualization algorithm was used to study the influences of sheath thickness, interference fit and rotation speed on rotor strength, and the feasible regions of sheath thickness and interference fit , under both static and high-speed running conditions, were obtained through intersection operation among the multi-dimensional visualization maps, subsequently, the optimal values of design parameters were selected in the feasible region. Finally, the validity of the design scheme was verified by the finite element method. The results show that the lumped solutions of the sheath thickness and interference fit can be obtained by the proposed optimal design method based on multi-dimensional visualization, and it is beneficial to achieve the robust optimization with the advantages of direct viewing and operation convenience. © 2022 Chinese Vibration Engineering Society. All rights reserved.