Diagnosis of Deterioration of Lithium Greases Used in Rolling-Element Bearings by X-ray Diffractrometry

In the present work, diagnosis of delenoration o f lithium greases The investigatiolls given i n this paper, along wilh the sludy o f used in rolling-element bearings by X-ray diffractornet? (XRD), damagedlcormgated bearing su?faces, have potenlial to diagnose and analysis by X-ray fluorescence spectromet? (XRFS) and atomic lhe cause of bearing failure under the influence of eleclrical fields, absorption speclrophotomet? (AAS) is reported. These techniques and also, to establish the severity of deterioralion of lhe lithium gzve reproducible reliable data to establish the severity of deleriogreases wed i n lhe bearings. ration of greases recovered from the active zone of lhe bearings. X R D appears to be suitable to diagnose quickly the chemical changes IN'rRODUC-rION occurred i n the soap residue of the greases, available even i n small quantity, compared to lhe other analytical and pe?formance evalIt is often necessary to analyse a grease for quality, developmental work, trouble-shooting and machinery-health uution techniques. This paper gzves diagnosis of the fresh lilhium greases, chemical diagnostic studies. The amount and depth of analytical work required will, of course, depend on desired objectives. This compositiolls and formation of new compounds i n the greases after can range from a simple to a great deal of sophisticated, being used in the rolling-element bearings operated under the inexpensive, and time-consuming analysis. There are various fluence of electrical fields, and also under pure rolling friclion analytical techniques available; physical tests, infra-red specwithoul lhe effect of electricalfields on the roller bearing test rig. troscopy, mass spectrometry, emission and atomic absorpThe deteriorated greases rfxovered from various bearings tion spectrophotometry, X-ray fluorescence spectrometry have also been analyzed and results are compared wilh that of the (XRFS), and X-ray diffraction (XRD) and various other pergreases from lhe test bearings. formance evaluation tests (I) . The X-ray diffraction analysis shows that the chemical compoDespite the wide use of lubricating greases, most of the &ion of the soap residue of the fresh lithium grease is lithium studies are concerned with their structure, manufacturing, stearate (Cis H s s Li 02), which does not change in the bearings processing, mechanical testing and evaluation (Z), (3). A few