Measurement of EHLfilm thickness in Rolling Element with micro-textured surfaces

Abstract

This study presented a measurement error for determining the thickness of thin film lubrication based on optical interference methods. The measurement error is caused by the reflective index distribution on the surrrface, which is characterized by the profile of the surface. In order to demonstrate the measurement error，two types of simplified optical models were proposed． Adding to this, we made specimens with the reflectance distribution and measured the oil film thickness. As a result, it was found that the reflective index distribution sometimes acts to underestimate the measurement values of the thickness. The founding of this study provided a new insight for improving the measurement accuracy of thin film measurement using optical interference methods.