Affiliations: [a] College of Astronautics, Nanjing University of Aeronautics and Astronautics, Nanjing, China | [b] Aerospace System Engineering Shanghai, Shanghai, China | [c] Guangxi University of Science and Technology, Liuzhou, China
Correspondence:
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Corresponding authors: Chen Fan, College of Astronautics, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China. E-mail: chenfan@nuaa.edu.cn. Zhang Chongfeng, College of Astronautics, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China; and Aerospace System Engineering Shanghai, Shanghai, China. Tel.: +86 15618166526; E-mail: 15618166526@163.com
Abstract: In order to solve the problem of short service life (2 months) and zero leakage of air cylinder in aerospace engineering, this paper innovatively designs a magnetic fluid sealing device of air cylinder in aerospace engineering through magnetic circuit analysis and magnetic fluid sealing theory. The magnetic field finite element method is used to calculate the magnetic field distribution in the sealing gap under different key parameters such as the number of pole teeth, the height of the radial sealing gap, the thickness of the permanent magnet, the slot width, the ratio of pole piece height to shaft. And numerical analysis of the number of pole teeth, the radial sealing gap height, permanent magnet thickness, slot width, the ratio of pole piece height to shaft and other key parameters on the magnetic fluid sealing performance. Finally, the reliability of the reciprocating magnetic fluid sealing withstand voltage is verified by experimental methods. Research indicates. The pressure capabilities of magnetic fluid sealing is increasing with the increase of the number of pole teeth. The pressure capabilities of magnetic fluid sealing is decreasing with the increase of the radial sealing gap. The sealing withstand voltage increases first and then decreases with the increase of the thickness of the permanent magnet, and finally increases, and the value of the withstand voltage is the largest when the thickness of the permanent magnet is 7.8 mm. The sealing pressure capabilities increases as the slot width increases. The sealing withstand voltage increases first and then decreases as the ratio of pole piece height to shaft increases, and when the ratio of pole piece height to shaft is 0.8, the sealing withstand voltage reaches a maximum value. The pressure test finally reaches the pressure value of 6 MPa, which can meet the pressure value demand of medium pressure cylinder, indicating that the magnetic fluid sealing technology can effectively solve the leakage problem existing in the air cylinder technology of Aerospace Engineering, and improve the reliability and service life of the air cylinder.
Keywords: Aerospace engineering, air cylinder, magnetic fluid sealing, numerical analysis, key parameters, experiment
