Analysis and Experiment of Vibration Isolation Performance of a Magnetic Levitation Vibration Isolator with Rectangular Permanent Magnets

Purpose: Magnetic levitation vibration isolator (MLVI) is an efficient method to suppress the external oscillations transmitted to some small instruments in the laboratories. Methods: This paper first presents a basic configuration of a kind of MLVI with four sets of the repulsive rectangular permanent magnets. Then, the parametric studies are carried out to discuss how the structure and air gap parameters influence the magnetic force, stiffness, and natural frequency of the MLVI. Moreover, as an MLVI case study, an operating point is set and the size dimensions of the MLVI are determined based on the parametric studies. The transmissibility of the MLVI is calculated by the dynamic equation at the operating point. Results: An experimental table is constructed for the analytical validation. The experimental results proved the validity of the theoretical analysis and showed that there are good consistencies between the experiment results and the theoretical calculation, which obtains that the natural frequency of the MLVI is 4.75 Hz and the initial cut-off frequency of the MLVI is approximately 6 Hz at the operating point. When the frequency of the external oscillations reaches 16 Hz, the attenuation amplitude becomes -?20 dB. Conclusion: All of these show ability of the proposed MLVI to attain low-frequency vibration isolation, and provide a new type of basic passive MLVI to exploit an active MLVI for practical applications.