Development of a strain sensor for rolling contact loads

Development of a strain sensor for rolling contact loads. - A strain sensor for high spatial resolution and low response time for rolling contact loads was developed and applied to an axial cylindrical roller bearing. The sensor consists of 100 nm thick titanium and is embedded in an aluminum oxide layer of 500 nm thickness that acts as a wear resistant and insulating layer. For an easy transfer of the process to radial surfaces only one photolithographic step is used. The sensor was characterized and compared to an A.S.T. KAF-S load cell. Due to the small form factor the spatial resolution is in the range of 500 μm. The double basic dynamic load rating per rolling element was tested and good linearity was achieved. Possible application areas are structural health monitoring of large machines such as wind turbines or the verification of simulation results of roller bearings.