Numerical study on key parameters of ferrofluid seal with large gap and two magnetic sources

Abstract

In order to improve the pressure capacity of ferrofluid seal with large gap, ferrofluid sealing structure with two magnetic sources was designed. The magnetic field distributions in its sealing gap were analyzed by finite element method. The effects of sealing gap, ratio of permanent magnet length to its height, slot width and ratio of the pole piece height to the shaft radius on ferrofluid seal have been investigated. The results show that the pressure capacity of ferrofluid seal decreased significantly with the increase of the sealing gap. Its pressure capacity increases initially, then decreases and remains unchanged at last with the increase of the ratio of permanent magnet length to its height. Its pressure capacity decreases firstly and then increases with the increase of the slot width. Its pressure capacity increases firstly and then decreases with the increase of the ratio of the pole piece height to the shaft radius.