Experimental Research on Divergent Embedded Magnetic Fluid Static and Dynamic Seals with a Large Gap

Abstract

Magnetic fluid sealing (MFS) is one of the most advanced applications of magnetic fluids (MF). To improve the pressure resistance of the traditional MFS with a large gap, this paper proposes a large-gap divergent embedded magnetic fluid seal (DEMFS) structure with radial and axial sealing capabilities. Through the simulation analysis of the radial and axial seal gaps (0.5–0.8 mm) and the number of radial and axial pole teeth (PT), the theoretical pressure resistance was obtained. A large-gap DEMFS test bench was built to experimentally verify the simulation results, and the effects of the MF volume and shaft speed on the pressure resistance of the sealing device were also experimentally investigated and compared with the theoretical pressure resistance of the traditional MFS structure. The numerical simulation and experimental results that the experimental values of the DEMFS are in good agreement with the theoretical values. When the MF injection volume was 2.5 ml, the pressure resistance reached the maximum and tended to be stable. With the change in the size of the seal gap and the number of PT, the variation trend of the pressure resistance of the DEMFS was different from that of the traditional MFS. When the shaft speed was low, the low speed had almost no effect on the pressure resistance of the DEMFS. The axial seal gap and axial PT were beneficial to the sealing effect.