Oil Fog Lubrication of High Speed Ball Bearing

Abstract

In pursuit of information concerning performances of the preloaded ball bearing operating under the oil fog lubrication at high speed, the coefficient of friction and the temperature rise have been measured for the angular-contact-type ball bearing. In the practice of the oil fog lubrication, the influences of oil consumption, air consumption, viscosity and additive of oil, preload and rotating speed are investigated and compared with those of the ordinary oil lubrication. It is possible to lessen remarkably the friction of high speed ball bearing by the aid of the oil fog lubrication with less supply of oil. Even in that case, the oil fog lubrication is mostly the hydrodynamical lubrication ; consequently the friction of ball bearing under the fog lubrication depends principally on the viscosity of oil. The cooling effect of air is fairly great, but the effect of air on the bearing temperature rise is less than that of oil under the definite ratio of oil and air. Though the temperature rise and frictional moment increase proportionally to preload, the increase of preload does not influence so much upon the temperature and friction when oil is supplied sufficiently. As the rotating speed increases, the bearing temperature rises very rapidly, on the contrary the coefficient of friction increases gradually.