Abstract: In some special applications, especially in the military industry, a magnetic liquid sealing technique is needed to solve the problem of leakage in the large gap. To improve and verify the pressure capability of magnetic liquid seal with large gaps, a magnetic liquid sealing structure with multiple magnetic sources is designed. The sealing capability and self-healing capability of magnetic liquid seal with multiple magnetic sources with 0.4 mm, 0.5 mm, 0.6 mm and 0.7 mm gaps are investigated by using experimental methods. The relations between the experimental results of magnetic liquid seal with multiple magnetic source and the theoretical results of magnetic liquid seal with single magnetic source are analyzed. The results show that the sealing capability and self-healing capability of magnetic liquid seal with multiple magnetic source decrease with the increase in gap height; the pressure capabilities of magnetic liquid seal with multiple magnetic source are 4.7, 3.8, 2.8 and 2.5 times of that of a magnetic liquid seal with single magnetic source for four different sealing gaps. In addition, the magnetic liquid seals with large gaps and multiple magnetic sources have good self-healing capabilities.

Key words: general engineering technology, large gap, multiple magnetic source, magnetic liquid, seal, self-healing