Experimental Study on the Pressure Transfer Mechanism of Embedded Magnetic Fluid Seals

Abstract

Although the sealing mechanism of the embedded magnetic fluid seal is unclear, it is an effective way to improve the performance of the ordinary magnetic fluid seal. Embedded magnetic seals can be divided into diverging and converging embedded magnetic fluid seals, according to the direction of leakage of the sealed medium. This article mainly focuses on presenting a sealing device that can observe the change in the shape of the magnetic fluid film and investigate the mechanism of diverging and converging embedded magnetic fluid seals. The pressure transfer mechanism of the embedded magnetic fluid seal with a large gap was studied through experiments. Numerical analysis of the magnetic field distribution in the seal gap and calculation of the theoretical pressure capacity of the embedded magnetic fluid seal are produced on the basis of embedded magnetic fluid seal theory. The experimental pressure capacity is compared with the theoretical pressure capacity to verify the correctness of the embedded magnetic fluid seal pressure capacity theory. The research has investigated the effect of the number of magnetic fluid film ruptures on the self-restoring capacity of embedded magnetic fluid seals, compared with the self-restoring capacity of diverging and converging embedded magnetic fluid seals, and analyzed the data. The results illustrated that the experimental pressure capacity of the embedded magnetic fluid seal matched well with the theoretical pressure capacity, which verifies the correctness of the embedded magnetic fluid seal theory. The pressure transfers from one chamber to another when the pressure difference between the two sides of the magnetic fluid film under the pole tooth is larger than the pressure capacity of the magnetic fluid seal, and the air will enter from the high-pressure side seal chamber to the low-pressure side seal chamber, in turn. As the inlet pressure increases, the pressure trend in the radial chamber of the embedded magnetic fluid seal differs from that in the axial chamber. When the seal fails, the magnetic fluid shows microleakage and complete leakage. As the number of magnetic fluid film ruptures increases, the self-restoring capacity first decreases and then increases. The self-restoring capacity of the converging embedded magnetic fluid seals is better than that of the diverging embedded magnetic fluid seals.