Research On The Characteristics Of The Rolling Bearings With The Oil-air Lubrication

Rolling bearings are widely used in mechanical equipment, and the working condition of the equipment system depends on the effectiveness of the lubrication states. In recent years, along with the rapid development of the oil-air lubrication, the new type of lubrication technology increasingly being used in the rolling bearings.With the development of the Computational Fluid Dynamics (CFD), the computational fluid dynamics software becomes mature gradually, which provides the way to analyze the multi-physical coupling. The research of thermal-mechanical coupling and thermal-fluid coupling of the rolling bearing are now the hot topics.Based on the application of the oil-air lubrication in the rolling bearings, the cylindrical nozzle’s flow field and the temperature field of the rolling bearings are main research objects in this thesis. The Fluent, a kind of CFD software, is employed in the simulation of the research. The flow field in the nozzle and the thermal field in the bearing under the oil-air lubrication condition are discussed in this thesis. The research results will be provided to support the industrial application of the oil-air lubrication.The research results are shown as follows,(1) The nozzle’s internal flow field and external flow field are relevant to the structure of the nozzle under the state of the annular flow. The falloff angle and the outlet diameter of the nozzle have the great effects on the flow of the oil film.(2) The speed of the rolling bearing and the oil’s viscosity have great effects on the calorific value of the bearing. The bearing heat transfer coefficient has the relevant to the bearing speed and the flux of the compressed air. When the diameter of the nozzle is small, the air velocity in inlet has little effect on the heat transfer coefficient.(3) The heat source and the amount of generation of the deep groove ball bearing are analyzed and calculated in the condition of oil-air lubrication. The Fluent is used to simulate the three-dimensional thermal-fluid coupled model of the bore and the operating temperatures of bearing are obtained under different operating conditions. Comparing with the simulation results of bore under the condition of oil lubrication, the temperature of bearing under the oil-air lubrication is much lower.