Control of oil film thickness for hydrostatic journal bearing using PID disturbance rejection controller

The hydrostatic journal bearings are getting popular due to fulfilling the requirements of supporting heavy loads, high stiffness, and precise movement without wear and friction at low speed. The efficiency of hydrostatic bearing to support the load, depends upon the external source of pressure, which is responsible for supplying fluid at a certain pressure. Normally, external source of pressure is a pump, which has low efficiency and poor performance. This paper presents a servo feedback control system to achieve uniform oil film thickness so that shaft eccentricity is zero under different external loading conditions. The Paper presents some control strategies with a servo valve instead of a pump. The number of experiments has been done in Matlab/Simulink which shows that the proposed strategy has better results than PID strategy with respect to different external loading conditions. Furthermore, Proposed Strategy is checked with SAE 30 grade oil against different viscosity conditions (different temperature conditions) as well as different speeds conditions for verifying the hydrodynamic behavior of hydrostatic bearings. All the results of Matlab/Simulink show effectiveness and robustness of proposed strategy.