Design and pressure control of high-pressure differential magnetic fluid seals

Magnetic fluid seals have wide applications. The common two poles multistage seals cannot achieve a high seal capacity. Multipole and multistage magnetic fluid seals are an effective way to obtain a rather high seal capacity. In this paper, the design method for multipole and multistage magnetic fluid seals is presented. Methods to fill the magnetic fluid and to apply a pressure differential are investigated. Experimental results show that the designed seal device can bear a pressure differential of 2.7 MPa. By a pressure applying control method, the seal capacity can be further increased.