Papers by Keyword: Elastohydrodynamics

Abstract: Based on a theoretical model and an experimental methodology for defining the friction torque in a modified thrust ball bearing having only 3 balls and presented in [2], the authors experimentally investigated the influence of the ball diameter on friction torque when operating in mixed and full film lubrication conditions and maintaining the normal load, the race curvature and oil viscosity constant. The experiments were realized using ball diameters between 7.938 mm and 3 mm corresponding to maximum Hertzian pressure between 0.264 GPa and 1 GPa and a rotational speed between 60 rpm to 240 rpm. The experiments confirmed that the measured friction torque can be explained using hydrodynamic rolling force relationships respecting the transition from IsoViscous Rigid (IVR) to ElastoHydrodynamic Lubrication (EHL) regime presented in [2].

Abstract: This work is an investigation of the performance characteristics of an offset journal bearing lubricated with a fluid with couple stresses taking into consideration the elastic deformation of the liner. The couple stresses might be expected to appear in noticeable magnitudes in liquids containing additives with large molecules. The modified Reynolds equation has been solved using the finite difference method. Load carrying capacity, attitude angle, side leakage and friction coefficients are determined for various values of couple stress parameter of a rigid and deformable bearing. It is found that, the static characteristics of journal bearings lubricated with couple stress fluids are improved compared to journal bearings lubricated with Newtonian fluids. It is concluded that, the elastic deformation of the bearing has significant influence on the bearing characteristics.