Influence of High Electrical Currents on WEC Formation in Rolling Bearings

A review of advances in tribology in 2020–2021

“…WEC, or white etching areas (WEAs), or white structure flaking (WSF) in other words, is a special type of RCF failure, often found in transmissions of electric motor power trains, especially controlled with a modern converter. WEC failures have a much shorter fatigue life compared with those of non-WEC fatigue failures, and have cross-sectional features which are distinctive from RCF [267].…”

“…Many research results have shown that WEC correlates strongly with the hydrogen generation from the base oils and/or additives involved under frequent discharging. Influence of high electrical currents on WEC failures in a number of oil-lubricated cylindrical roller bearings and grease-lubricated ball bearings was investigated under different external voltage applications on a bearing tester [267]. It is found that current intensity, electrical polarity, and load type have strong influence on WEC formation while the effect of lubricant is relatively weak.…”

“…The authors in Ref. [267] proposed an "energetic WEC fatigue" hypothesis, shown in Fig. 26, to explain their observations.…”

“…Fig 26. Root cause hypothesis for WEC formation due to bearing currents[267]. Reproduced with permission from Ref [267],.…”

“…Root cause hypothesis for WEC formation due to bearing currents[267]. Reproduced with permission from Ref [267],. © Society of Tribologists and Lubrication Engineers, 2021.…”