Investigation of the ball-bearing temperature rise under an oil-air lubrication system

Ball-bearings are widely used on many high-speed rotating systems. However, heat generation and dynamic loading caused by high-speed operation have be en the limiting factors for increasing the speed limit of many high-speed b all-bearing applications. Therefore, providing proper lubrication and prelo ad to reduce heat generation effectively is a major task for high-speed bal l-bearings. Recently, oil-air lubrication has been used on high-speed ball-bearings bec ause of precise oil quantity control and high cooling efficiency. However, the fluctuation in oil supply resulting from the periodic oil feeding is un favourable. In this study, equipment for measuring the fluctuation in the o il supply was established. The operation parameters affecting the stability of the oil supply for an oil-air lubrication system were experimentally st udied. A test rig for high-speed ball-bearings was also developed. Tests we re conducted to study the effects of the preload, oil quantity, air flowrat e and rotating speed on the bearing temperature rise. The operating conditi ons that provide a stable oil supply and low bearing temperature rise were established.