Vibration properties of full ceramic bearing under elastohydrodynamic fluid lubrication based on the energy approach

As an important part of rotating machinery, heat generation due to friction is inevitable during the rotating process of bearings. A large amount of heat causes the temperature of lubricating oil to increase, viscosity of lubricating oil to decrease, and lubricating performance decreases. Addressing the issue of inadequate lubrication between the rolling element and raceway due to increased lubricating oil temperature, this study focuses on full-ceramic ball bearings. It examines the impact of temperature fluctuations on the bearing's lubrication condition and investigates the vibration characteristics of the full-ceramic bearing. The variation in the viscosity of lubricating oil with respect to temperature is measured via a rotary viscometer. A dynamic model of the silicon nitride full-ceramic ball bearing, which considers the effects of elastohydrodynamic lubrication, is established. The impacts of changes in lubricating oil viscosity due to different temperatures on oil film pressure, oil film thickness, and bearing vibration are analyzed and then compared with experimental data. It is observed that under conditions of constant load and speed, the film thickness of the lubricating oil decreases as the viscosity decreases. Additionally, the second peak value of oil film pressure is reduced with the declining viscosity of the lubricating oil. As the viscosity decreases, the vibration of the bearing increases. The amplitude discrepancy between the simulated vibration signal and experimental vibration signal of the full-ceramic bearing is found to be less than 10 %, verifying the validity of the dynamic model. • The research establishes a dynamic model of silicon nitride 6206 full ceramic bearing under elastohydrodynamic lubrication based on energy method. • This article explores the influence of changes in lubricating oil temperature on bearing vibration. • The relationship of oil film pressure, oil film thickness, and bearing vibration. • This research verifies the correctness of the model established in this article through vibration tests on full ceramic bearings. • Under the condition of constant load and speed, the oil film thickness of lubricating oil decreases and the vibration of bearing gradually increases when the viscosity of lubricating oil decreases.