Numerical and experimental study of the embedded magnetic fluid seal with a small gap

To improve the pressure capability of the ordinary magnetic fluid (MF) seal (MFS) with a small gap, a device of the embedded MFS is designed according to the theory of embedded MFS. The magnetic field distribution in the seal gaps of the embedded MFS was studied by employing the finite-element method, and the theoretical pressure capability of the seal are calculated. A seal experimental platform was designed and built. The effects of MF injection volume, radial seal gap height, axial seal gap width, number of radial pole teeth (PT), number of axial PT, and the ratio of PT length to its width on the pressure capability of embedded MFS device was investigated, and compared to the experimental pressure capability of the ordinary MFS. The results show that the experimental and theoretical pressure capabilities of the embedded MFS are in good agreement. When the MF injection volume is 1.5 ml, the pressure capability has reached the maximum and tends to be stable. The pressure capability of the embedded MFS is better than that of the ordinary MFS. The pressure capability of the embedded MFS is not only related to the size of the seal gap and the number of PT but also related to the ratio of PT length to its width.