Temperature Influence on the Behavior of a Magnetorheological Fluid Journal Bearing

Abstract

Active control of vibrations is an important capability of bearings using magnetorheological fluids as lubricants. Magnetorheological fluids are a suspension of micron sized iron particles in a carrier fluid, usually a mineral oil. These particles, polarized under the influence of a magnetic field, form chains inside the lubricant volume, they hinder the flow of the fluid, change its apparent viscosity and offer active control on the available damping of the bearing. Magnetorheological fluid's apparent viscosity relies heavily on the viscosity of the base fluid. The base fluid's viscosity depends on temperature. On the other hand the existence of particles is a factor that may influence the lubricant's temperature. In this paper the dynamic characteristics of a journal bearing lubricated with magnetorheological fluids are investigated for a range of temperature and load conditions.