Eco-friendly air-oil lubricated angular contact ball bearings. Shows the structure of an eco-conscious type bearing that was developed for further energy conservation. It was found that the lubricant adhesion and flow using sample inner rings of diameter 100mm ID and diameter 70mm ID and different swash angles. Lubricant readily adheres and flows if the swash angle is large and the rotating speed is fast. These results indicate that a larger swash angle produces a larger component force of centrifugal force, making lubricant more readily adhere and flow and that faster rotating speeds cause swirling of air around the rotating shaft, preventing air-oil from adhering. In order to minimize the oil supply rate to air-oil lubricated rolling bearings that support the machine tool main spindles, this report concludes that the oil supply swash angle of the inner ring is determined by the d m n value and that minimizing oil wettability of tubes is effective to reduce the fluctuation of oil delivery into bearings at the oil nozzle. 

Eco-friendly air-oil lubricated angular contact ball bearings works as a safe, economic and pollution free lubrication. With a lubricating hole (groove and hole in the outer ring) the amount of lubricant can be controlled and is released precisely into the bearing, even under high speed. This reduces the number of parts in the bearing and simplifies the overall possible construction of the spindle.