The influence of various grease compositions and silver nanoparticle additives on electrically induced rolling-element bearing damage  

作　　者：Samuel BOND Robert L.JACKSON German MILLS 

机构地区：[1]Department of Chemistry and Biochemistry,Auburn University,Auburn 36849-5412,USA [2]Department of Mechanical Engineering,Auburn University,Auburn 36849-5412,USA

出　　处：《Friction》2024年第4期796-811,共16页摩擦（英文版）

摘　　要：Leakage currents accelerate surface degradation of metal contacts via small scale arcing across lubricating films,but recent observations suggest that metallic nanoparticle additives in lubricants may be useful to improve contact performance.These findings prompted a study that examined electrically induced surface pitting of steel contacts in the presence of several lubricating greases including some containing nanometer-sized colloidal silver(Ag)particles.Reciprocating rolling sphere-on-disk experiments were conducted under electro-tribological loads employing polyurea greases derived from mineral and synthetic base oils with and without additives.Friction forces and electrical resistance were monitored continuously during the tests;surface changes were characterized by means of optical spectroscopy,stylus profilometry,and scanning electron microscopy(SEM)including compositional analysis using energy dispersive spectroscopy(EDS).The observations demonstrate that surface pitting induced by arcing occurs mainly at the points were the rolling motion changes direction and that eroded metal is deposited along the wear grove.Micron-sized pits are formed which contain carbon and oxygen indicating that arcing causes decomposition of the hydrocarbon lubricants.Numerous findings indicate a significant inhibition of pitting is induced by the Ag nanoparticles;some greases containing other additives exhibit a similar,although less pronounced,effect.

关 键 词：electric motor bearings wheel bearings electric vehicles ARCING electrically induced bearing damage PITTING leakage current stray current 

分 类 号：TE624.83[石油与天然气工程—油气加工工程]