Friction properties and distribution rule of lubricant film of full ceramic ball bearing under different service condition

Abstract

Full ceramic ball bearings are widely used in extreme and complex conditions, such as ultra-high/low temperature, ultra-high speed, corrosion and insulation, because of their material specificity. In order to reveal the friction and lubrication properties, improve the service performance life of all ceramic ball bearings, a mathematical model of the oil lubrication for full ceramic ball bearings has been established in this paper. The distribution rule of the lubricant film in the contact area under different speeds and loads were analysed. The main factors influencing the peak mutation of the lubricant film pressure are clearly defined. The results are compared and analysed by using a ball-disc rolling lubricant film test machine. The study found that the thickness of the lubricant film of a full ceramic ball bearing is positively correlated with the bearing speed and negatively correlated with the bearing loads. The bearing speed has a relatively large effect on the change in the lubricant film thickness. The pressure of the lubricant film in the contact area is positively correlated with the bearing speed, but it is not affected by the bearing load. Unlike metal ball bearings, the thickness and pressure of the lubricant film have a greater relative rate of change in different positions in the contact area of full ceramic ball bearings. With an increase in the bearing speed, the necking-down effect has a greater influence on the peak mutation of the oil pressure. Only one pressure peak occurs in the oil film in the contact area. The results of this paper play an important role in revealing the friction and lubrication properties of full ceramic ball bearings and improving their service performance and life under oil lubrication conditions.