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

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ORIGINAL PAPER

Analysis and Experiment of Vibration Isolation Performance of a Magnetic Levitation Vibration Isolator with Rectangular Permanent Magnets Qiang Li1 · Shan Li1 · Fengxu Li1 · Dengfeng Xu2 · Zhaoyun He1 Received: 17 August 2019 / Revised: 25 October 2019 / Accepted: 27 October 2019 © Krishtel eMaging Solutions Private Limited 2019

Abstract 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. Keywords  Rectangular permanent magnets · Magnetic levitation vibration isolator · Vibration isolation performance · Analysis and experiment

Introduction With the continuous increase in the precision of the scientific experiments, more advanced and precise instruments have entered the laboratories. For instance, balances, as the most important measuring instruments, are commonly put to use in some physical and chemical experiments. With the incensement of the measurement accuracy, micro-balances are used more and more broad, especially for those with high accuracy, reach microgram level and they will probably * Dengfeng Xu [email protected] 1



Artificial Intelligence School, Wuchang University of Technology, Wuhan 430023, China



Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China

2

become even higher and higher. However, the external disturbances may influence their measurement result and accuracy frequently, which probably come from the pedestrians, moving vehicles, floor vibration, the flowing air, etc. To reduce outer disturbances transmitted to the instruments, vibration isolation is an effective method. Many kinds of vibration isolators are applied in the field of the ultra-precision instruments