Study On The Temperature Distribution And Lubrication Performance Of Rolling Bearing

Lubrication and temperature both are the important factors to bearing. A reasonable oilsupply volume can be not only good for lubrication and reduce viscous drag loss, but alsopromote cost savings. Studying on the thermal performance of bearing contributes tounderstanding heat generation mechanisms of bearing, and further avoiding the failure anddamage of bearing caused by heat generation to some extent. Based thermo-electricityanalogy principle, the thermal network models for angular contact ball bearing and doublecolumn tapper roller bearing are established and the thermal behaviors of bearing areexplored. The main research contents and conclusions are as follows:For the ball bearing under the oil-air lubrication condition, the relationship between oillayer thickness on surface and supply time is established through oil layer measurementexperiments by oil-air generator. Then, the effects of oil layer thickness on lubricationperformance are investigated based on point-contact starved lubrication model and filmthickness decay model under different speeds, loads and surface roughnesses. The resultsshow that the time to fully flooded condition is hardly dependent on operating conditionsunder oil-air condition. There exists the optimal oil supply time and oil supply interval forestablishment of effective lubrication.On the basis of generalizing Ohm’s law and quasi-static model of bearing, a thermalnetwork model of high speed angular contact ball bearing with the oil-air lubrication isestablished, considering the various power losses such as the rolling friction and slidingfriction loss between ring and balls, the sliding friction loss between ring and cage, as wellas the drag viscous loss. The heat transfer models between different thermal nodes are built.The effects of lubricant flowrate, speed, the inlet oil temperature and the thrust load onthermal performance of bearing are investigated. The results show that the temperature ofbearing increases with the decrease of the lubricant flowrate, or the increase of speed. Arange of inlet oil temperature between25-40℃is recommended. An increasing thrust loadrestrains the slip of ball and makes the distribution of the temperature and heat generatitonat different ball-inner ring contact regions more uniform.Based on generalizing Ohm’s law, a thermal network model is developed for double-row tapered roller bearing lubricated with grease, using quasi-static model andHerschel-Bulkley model of grease. The model considers the friction losses between rollerand ring, roller large end and flange, the drag viscous loss as well. The temperatures ofbearing nodes and thermal behaviors at different speeds, filling grease ratios and roller largeend radii are investigated. The results show that the temperature of bearing increases withspeed and filling grease ratio. At a low speed, the power loss is mainly from the roller largeend-flange contact; however, in high-speed condition, the viscous drag loss graduallybecomes the main heat source. Besides, the radius of roller large end can be optimized tolower the heat generation at roller large end-flange contacts.