Temperature rise of hybrid ceramic and steel ball bearings with oil-mist lubrication

Temperature rise of ball bearings is the limiting factor to increase rotating speeds. Ball bearings with ceramic balls have been gradually used on many high speed rotating systems due to low material density, low thermal expansion, high Youngs modulus and hardness. Because of high cooling efficiency and low equipment cost, oil-mist lubricating systems have been widely used on various ball bearing systems. Oil-mist lubrication can provide ball bearings With steady air flow and continuous lubricating oil. A test rig for high-speed ball bearings with different lubrication systems has been developed. Performance tests of hybrid ceramic and steel ball bearings under different operating conditions including preload, airflow rate, oil quantity, and rotating speed were conducted in this test rig. The authors rest results show that the proper preload of hybrid ceramic ball bearings is lower than that of steel ball bearings. The temperature of ball bearings increase with the rotating speed and the hybrid ceramic ball bearing always has lower temperature rise than the steel ball bearing. When the oil supply rate is larger than the proper range, the temperature rise of hybrid ceramic ball bearing and steel ball bearing gets closer. Increasing the airflow rate is an efficient way to reduce temperature rise of ball bearings.