Pure squeeze film behavior of long journal bearings with couple stress fluids under dynamic loading

On the basis of microcontinuum theory, a theoretical analysis of pure squeeze film behavior of journal bearings with couple stress lubricants operating under a dynamic load is presented. To account for the effects of couple stresses arising from the lubricant blended with various additives, the modified Reynolds equation governing the film pressure is obtained from Stokes equations of motion. Various bearing characteristics for long bearings are then calculated. According to the results obtained, the influence of couple stresses on the dynamic squeeze film motion is apparent and not negligible. Comparing with the Newtonian-lubricant case, the effects of coupe stresses provide and enhancement in the film pressure as well as a reduction in the velocity of the journal center; consequently, the maximum eccentricity ratio of the journal center is decreased. On the whole, the bearing lubricated with couple stress fluid signifies and improvement in the dynamic squeeze film performance and results in longer bearing life.