Observation of the oil flow in a ball bearing with a novel experiment method and simulation

Actual volume of the supplied oil that functions as a lubricant in the contact regions of rolling bearings is intriguing and difficult to determine. In this study, we propose a novel experimental method that combines synchronized dual-camera imaging with laser-induced fluorescence (LIF) using extra illumination to observe the oil flow in a ball bearing. In addition, we perform simulations, which reveal that most of the oil layer adhering to the component surfaces is not directly involved in lubrication of the contact regions. The thickness of the oil layer along the rolling contact trace decreases markedly as the decayed area appears. The oil layer decay severely weakens the oil replenishment, and its degree increases with the capillary number Ca.