The Influence of Shaft Eccentricity on the Magnetic Fluid Sealing Performance

Abstract

This manuscript delves into the impact of shaft eccentricity and diameter on the pressure resistance and magnetic force of a magnetic fluid seal (MFS), through both magnetic circuit analysis method (MCAM) and finite element method (FEM). The study proposes a systematic approach to enhance the performance of eccentric MFS based on MCAM. The results show a near-linear decrease in the pressure resistance of the MFS with increasing eccentricity, with a maximum decline of 65 %. However, the MFS model with a 100 mm shaft diameter renders more precise results in predicting the sealing performance for larger shaft diameters since the pressure resistance decrease remains below 5 % as shaft diameter is increased. The optimal range of pole tooth structure parameters has also been determined. Remarkably, the proposed method affords a precise analysis of the performance of large-diameter eccentric MFS, which is not feasible using two-dimensional axisymmetric magnetic field models.