The effect of oil feed pressure on the friction torque of plain bearings under light, steady loads

Friction losses in plain bearings can be reduced by reducing the pressure of the oil feed. The role of increased film cavitation has been investigated experimentally under light, steady loads for a bearing with a 180° groove, using an SAE 5W-30 oil. Friction torque was reduced by up to 18% by increased cavitation which reduces the film area and the eccentricity ratio. The latter reduces the surface shear stress in the load-bearing region of the film and overall, the circumferential average. As load increases, the reduction in film area accounts for an increasing proportion of the friction torque reduction.