Phot ogra phs &   Lubric ant S amples  of the Be aring Assy Remo val of  Bearings from  the Be aring Assy Inspec tion of Bearing 2  • Photo Document ation  • Remove Lubrica nt Samples • Clean Parts & Ba g Disasse mbly  of Beari ng 2 Disasse mbly  of Beari ng 1 Bearing 1 & 2 Lubrica nt  Samples,  Weigh t, and  Inspec tion (Photogra ph) Lubric ant Flush & Ball Analyses • Lubricant Sample Anal yses  • Surface Anal ysis of 4 Balls from  Each Bearing  Inspec tion of Bearing 1  • Photo Document ation  • Remove Lubrica nt Samples  • Clean Parts & Ba g Rota te Eac h Bearing   Videotape Motion of  the Ba lls & Toro ids& Bearing P art, Lubrica nt &  Particle A nalyses  • FTIR Anal yses  • ESCA on Balls for TCP & FeF 3 Perform SEM/E DS  Analyses of Bearings   1 & 2 Parts a nd Particles   Bearing /   Lubric ant  Inspec tion  nal Repo Fi rt Bearing Desi gn /  Oper ation  Repor t /  Reco mme ndationGeometry  Measure ments  on Be aring 1 &  2 Parts 

Figure 5.  Be aring Inspec tion and Op eration Flo w 

It is a rare occasion that the nominal  acceptance or qualification tests will be sufficient for investigating a  specific me chanism  anoma ly. Therefo re, a test plan should  be generated  to gather mo re detail rega rding  the likely ca uses of the anomaly. On ce the unit i s torn down, it is proba ble that it coul d never b e  reassembl ed in a way that wo uld repro duce the identi cal anomaly. Gen erally, me chanism  torq ue  informatio n can be deduced from  mot or curre nt amplitude a nd profile, m otor voltag e levels, torq ue  transducer tests, and velocity tests. Position accuracy tests can provide an  indication of m echanism wear,  slop or hardware fail ure. Often, these tests may n eed t o be run at operatio nal environme ntal tempe rature   and va cuum conditions to obtain a ccurate data. Ot her testing may be ne cessary base d on t he spe cific  function s of a mech anism. The key is to be fa miliar eno ugh with the mechani sm and the analytical   techni ques available to co mpletely evaluate the unit. 

Once the te st prog ram i s com plete a nd the u nit disassembly h as begun, th ere are seve ral meth ods  available fo r investigatio n of the moving  mechani cal parts such a s the bea rings and lu bricant in the case  of the FGS S SS. It is impo rtant to ta ke contami natio n and  lubricant sam ples at variou s points throug hout  the tear down process since the se may  later p rovide an in dicatio n of anom aly sources. Sa mples can b e  taken by using a clean swa b on th e surfa ce, pe rforming a Freon or IPA (Isop ropyl Alcoh ol) filtered ri nse o r  simply rem oving a large p article u sing a clean tool such as d ental pick o r tweezers. Tech nique s for  hardware surface and contaminant  anal ysis used for the FGS Serv os incl ude F TIR, SEM/EDS, XPS (or  ESCA), ICP/MS and O LM (define d below). Comp onent we ights should al ways be included in the process  when lubricant quantities are in q uestion. Ho weve r, caution should be u sed in  drawing conclusions from  mass m easurements since lubricant amounts can be extremely small an d lubricant loss can be replaced  by contamin ates re sulting i n a false inference. 

FTIR (Fourier Transform Infrared) Spec troscopy Ana lysis provid es d etailed molecula r informatio n on   organic comp lexes a nd some ino rganic gro ups, thereby aidin g in material  identification. Th e inst rume nt  347