Dynamic Prediction Of Friction Torque And Analysis Of Thermal Characteristics In Grease Lubricated Angular Contact Ball Bearings

Due to its high limit speed, low friction torque and high precision, angular contact ball bearing has become the main support of high speed motorized spindle. However, the frictional heat and temperature rise are still the main factors that affect the improvement of speed and life of the angular contact ball bearings. Therefore, the analysis of friction torque and heat have important theoretical significance and practical application value. Thus, this paper studies the friction torque and thermal characteristics of the angular contact ball bearings.Based on the grey system theory, the dynamic prediction model of angular contact ball bearing friction torque is established considering the influence of temperature, rotational speed and drag coefficient of the B7009C/P4 bearing. In order to verify the accuracy of the prediction model, on-line and off-line methods are used to predict the friction torque. The results show that, for the on-line prediction method, prediction value has the same trend with experimental value, the maximum and mean error between prediction value and experimental value are 10.2% and 3.6%, above 90% of the friction torque can be predicted correctly; for the off-line prediction method, the maximum and mean error are 11.9% and 5.1%, above 85% of the friction torque can be predicted. In summary, the grey prediction model has a high accuracy and stability in predicting the friction torque, which provides a theoretical reference in analyzing friction torque of angular contact ball bearings.Based on the analysis of the heat transfer of angular contact ball bearings, the thermal analysis model of the experimental bearing is established. The mesh and thermal loading of testing bearings are studied to solve the steady-state temperature field, and the steady-state temperature distribution is obtained; the transient thermal analysis is performed on the basis of steady-state thermal analysis. Finally, the simulation value of inner ring temperature is obtained, and the validity of thermal analysis model is verified by the experimental results. The study provides a theoretical reference for the optimal design of grease lubricated angular contact ball bearing structure.