Controllable Misaligned Journal Bearings, Lubricated with Smart Fluids

The controllable rheological behaviour of Electro-Rheological Fluids (ERF) is useful in engineering systems where variable performance is required. In particular the ERF have properties which are changed by an imposed electric field. In this paper a generalised Reynolds equation is solved using finite element techniques in order to simulate the behaviour of misaligned journal bearings lubricated with ERF. The Bingham plastic model is used to described the behaviour of the ERF, when the fluid is in flow mode. It is found that the applied electric field has a substantial influence on the load carrying capacity and the misaligned attitude of the journal bearings. It is concluded that the electric field imposed on the electro-rheological lubricant tends to align the journal in the bearing, making thus the misalignment angle smaller. Thus by changing the electric field it is possible to control the dynamic behaviour of rotor-bearing systems.