Abstract
One of authors developed a complex lubrication system with an oil jet lubrication and an under-race lubrication system for angular contact ball bearings with dmn value < 390 million (dm = ball pitch circle diameter in mm, n = speed in min-1). In order to increase the speed limit of bearings, we have developed a new lubrication system. In this paper, the eco-friendly oil jet lubricated bearings and a lubrication system are introduced. The power loss and the temperature of the eco-friendly oil jet lubricated bearings are almost equal to those of the air-oil lubricated bearings under dmn value 250 million and the eco-friendly oil jet lubricated bearings with 70mm in bore diameter were successfully operated at dmn value 500 million.