Application of triboelectric charging effect for engine lubricating oil degradation monitoring

Abstract

Lubrication of machine parts is necessary to prevent friction and wear in machine operation. Even the slightest reduction of friction and wear cause a huge positive impact in the economy since almost all machines in our current industry suffer from the energy and material losses caused by these events. Therefore, maintaining good and stabilized lubrication is vital for this purpose. However, oxidation of lubricants upon operation brings about unwanted changes in its chemical and physical properties and causes lubrication performance to deteriorate. Thus, a better understanding of lubricant condition and its variation under different parameters can enable technologists to make informed decisions to ensure lubrication excellence and optimization of the lubricant's renewal time. However, current methods for detection of oil deterioration lack practicality and exibility. In this study, a novel method was put forward to estimate the remaining service life of several types of commercially available engine lubricants using triboelectri fication. A Triboelectric sensor (TES) was developed and this TES was given different open circuit voltage (Voc) values according to the different oxidation time of lubricant oils. These results were then correlated with FTIR-ATR analyses of the oils. Additionally, we reported the dynamic viscosity changes of engine oil samples upon oxidation. We believe the results presented in this thesis convey the basis for establishing a TES for straightforward detection of deterioration of engine oil.