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.