Structural Design and Lubrication Properties under Different Eccentricity of Magnetic Fluid Bearings

Abstract

As a lubricant, the viscosity of the magnetic fluid changes with the external magnetic field, which improves the bearing capacity of the oil film and hence the lubrication effect, and has a promising application in bearings. Based on the Roelands viscosity theory, the Shliomis model is used to derive the viscous temperature, viscous pressure, and magnetic viscosity characteristics of magnetic fluids under the influence of an applied magnetic field, and further proposes a structural model of magnetic fluid lubricated bearings to investigate the pressure, temperature and magnetic intensity distribution of magnetic fluids under different eccentricity conditions. The results show that the viscosity of the magnetic fluid decreases exponentially with increasing temperature, rises linearly with increasing pressure, and increases and stabilizes with increasing magnetic induction strength. Because the minimum film thickness point is the dividing point between the convergent wedge and the dispersed wedge, the pressure distribution of the lubricant film separates high pressure from low pressure at the minimum film thickness, and the differential pressure increases with the increase in eccentricity. The temperature distribution of the high-temperature zone is mainly distributed in the middle of the film, and the minimum film thickness zone and the maximum temperature increases with the increase in eccentricity. The magnetic intensity distribution of the strong magnetic field is mainly concentrated in the minimum film thickness zone, and the magnetic induction intensity increases with the increase in eccentricity. The results of this study have certain research significance for solving the problem of the poor lubrication effect of bearing lubricant due to high temperature.