In-situ electrical impedance observation for lubrication conditions of gears under actual operation

We investigated the effectiveness of the electrical impedance method (EIM) for in-situ monitoring of lubrication conditions in gear systems during operation. A custom-built gear tester equipped with spur gears and an alternating current circuit was used to evaluate lubrication regimes under different conditions. The temporal changes in EI signals were analyzed to estimate the thickness and breakdown ratio of the lubricant film at the gear mesh. The results revealed that the EIM effectively monitors the temporal changes in the lubricated conditions of the gear mesh. The technique also demonstrated the ability to monitor lubrication regimes by evaluating the thickness and breakdown ratio simultaneously. Thus, the EIM presents a promising tool for real-time monitoring of lubricated conditions of gear systems.