Influence of High Electrical Currents on WEC Formation in Rolling Bearings

Premature bearing failures due to white etching cracks (WECs) occur when the rolling contact is subjected to a so-called additional load such as an electrical current flow through the bearing in addition to the pure rolling load. Tests with oil-lubricated roller bearings and greased ball bearings showed that high electrical currents are a very critical WEC trigger. The influence of current intensity, electrical polarity, and load type (stationary ring load or rotating ring load) on WEC formation was proven by the performed bearing tests, whereas the influence of lubricant was relatively low. Based on the findings, the failure hypothesis "energetic WEC fatigue" was extended for high electrical currents.