Modeling and Validation of Diamagnetic Rotor Levitated by Permanent Magnetics

Featured as an innovative powerless and low stiffness suspension approach, diamagnetic levitation technique has trigged intensive interest because of its potential applicability in miniaturized mechanical system. The foundation of diamagnetic levitation system lies in mathematical modeling, which is essential for operating performance optimization and stability predication. However, to date, few literatures concerning the systematic mathematical modeling has been reported. Herein, in this work, a systematic mathematic model for disc-shaped diamagnetically levitated rotor on permanent magnets array is proposed. Based on the proposed model, the magnetic field distribution characteristics, diamagnetic levitation force characteristics (i.e. levitation height and stiffness) expressions and the optimized theorical conditions for realizing stable levitation are achieved. Experiments are also performed to dig out the relationship between levitation height and levitation force. Moreover, the operating stability of rotor under different conditions is evaluated. The experimental results are well in accordance with the theorical predications, confirming the feasibility of this mathematic model.