Performance Study of Thermal Expansion in Magnetic Fluid Seals for Large Centrifuges

During the operation of the magnetic fluid sealing device, a large amount of heat is generated due to the viscous friction of the magnetic fluid, causing the shaft to deform and thus affecting the sealing effect. This paper explores the thermal expansion effect of the magnetohydrodynamic sealing device under the working conditions of an axle diameter of 1030 mm and a maximum rotational speed of 700 r/min. The temperature distribution law under the action of a magnetic field, the influence of thermal deformation caused by temperature on the sealing performance, and the influence of the selection of shaft and pole shoe materials on the magnetic fluid sealing device were studied. Research findings show that in magnetic fluid sealing, an increase in system temperature can enhance the sealing effect, but it will cause thermal expansion of the rotating shaft and change the gap. By adopting a combination of different materials for the rotating shaft and the pole shoe, the sealing performance can be optimized and improved.