An Improved Dynamic Modelling for Exploring Ball Bearing Vibrations from Time-varying Oil Film

Abstract

Bearings are key components in rotating machinery, which is widely used in many fields, such as CNC machines, wind turbines and induction machines. The increasingly harsh operation environment can lead to wear and tear on raceways and reduce the precision and reliability of bearing or even machinery. Lubrication could relieve the wear to some degree, which is benefit to prolong the bearing’s life. Thus, investigation on the vibration responses under the influence of oil film is of great significance. However, for mechanism analysis, how to include the oil film into the bearing dynamic model affects the result and efficiency of solution. To address this problem, this study proposed a fast algorithm through load distribution and interpolation when calculating oil film stiffness and thickness during the solution of bearing vibration model. Analysis of oil film on vibration is carried out and a bearing test rig is designed to verify the proposed model. Numerical simulation result shows that rotational speed and load have vital effect on oil film and vibration, and oil film can play a role of shock absorption. The experimental result is consistent with the simulation, which shows that the proposed model has a better performance on modeling bearing vibration and the method of considering oil film is reasonable.