A Systems Approach to the Solid Lubrication of Foi

ChristopherDellaCorteandAntonioR.ZaldanaGlennResearchCenter,Cleveland,OhioKevinC.RadilU.S.ArmyResearchLaboratory,GlennResearchCenter,Cleveland,OhioASystemsApproachtotheSolidLubricationofFoilAirBearingsforOil-FreeTurbomachineryNASA/TM—2002-211482October2002ARL–TR–2867U.S.ARMYRESEARCHLABORATORYTheNASASTIProgramOffice...inProfileSinceitsfounding,NASAhasbeendedicatedtotheadvancementofaeronauticsandspacescience.TheNASAScientificandTechnicalInformation(STI)ProgramOfficeplaysakeypartinhelpingNASAmaintainthisimportantrole.TheNASASTIProgramOfficeisoperatedbyLangleyResearchCenter,theLeadCenterforNASA’sscientificandtechnicalinformation.TheNASASTIProgramOfficeprovidesaccesstotheNASASTIDatabase,thelargestcollectionofaeronauticalandspacescienceSTIintheworld.TheProgramOfficeisalsoNASA’sinstitutionalmechanismfordisseminatingtheresultsofitsresearchanddevelopmentactivities.TheseresultsarepublishedbyNASAintheNASASTIReportSeries,whichincludesthefollowingreporttypes:•TECHNICALPUBLICATION.ReportsofcompletedresearchoramajorsignificantphaseofresearchthatpresenttheresultsofNASAprogramsandincludeextensivedataortheoreticalanalysis.Includescompilationsofsignificantscientificandtechnicaldataandinformationdeemedtobeofcontinuingreferencevalue.NASA’scounterpartofpeer-reviewedformalprofessionalpapersbuthaslessstringentlimitationsonmanuscriptlengthandextentofgraphicpresentations.•TECHNICALMEMORANDUM.Scientificandtechnicalfindingsthatarepreliminaryorofspecializedinterest,e.g.,quickreleasereports,workingpapers,andbibliographiesthatcontainminimalannotation.Doesnotcontainextensiveanalysis.•CONTRACTORREPORT.ScientificandtechnicalfindingsbyNASA-sponsoredcontractorsandgrantees.•CONFERENCEPUBLICATION.Collectedpapersfromscientificandtechnicalconferences,symposia,seminars,orothermeetingssponsoredorcosponsoredbyNASA.•SPECIALPUBLICATION.Scientific,technical,orhistoricalinformationfromNASAprograms,projects,andmissions,oftenconcernedwithsubjectshavingsubstantialpublicinterest.•TECHNICALTRANSLATION.English-languagetranslationsofforeignscientificandtechnicalmaterialpertinenttoNASA’smission.SpecializedservicesthatcomplementtheSTIProgramOffice’sdiverseofferingsincludecreatingcustomthesauri,buildingcustomizeddatabases,organizingandpublishingresearchresults...evenprovidingvideos.FormoreinformationabouttheNASASTIProgramOffice,seethefollowing:•AccesstheNASASTIProgramHomePageat•[e-mail]•FaxyourquestiontotheNASAAccessHelpDeskat301–621–0134•TelephonetheNASAAccessHelpDeskat301–621–0390•Writeto:NASAAccessHelpDeskNASACenterforAeroSpaceInformation7121StandardDriveHanover,MD21076ChristopherDellaCorteandAntonioR.ZaldanaGlennResearchCenter,Cleveland,OhioKevinC.RadilU.S.ArmyResearchLaboratory,GlennResearchCenter,Cleveland,OhioASystemsApproachtotheSolidLubricationofFoilAirBearingsforOil-FreeTurbomachineryNASA/TM—2002-211482October2002NationalAeronauticsandSpaceAdministrationGlennResearchCenterARL–TR–2867U.S.ARMYRESEARCHLABORATORYTradenamesormanufacturers’namesareusedinthisreportforidentificationonly.Thisusagedoesnotconstituteanofficialendorsement,eitherexpressedorimplied,bytheNationalAeronauticsandSpaceAdministration.Thisreportcontainspreliminaryfindings,subjecttorevisionasanalysisproceeds.TheAerospacePropulsionandPowerProgramatNASAGlennResearchCentersponsoredthiswork.AvailablefromNASACenterforAerospaceInformation7121StandardDriveHanover,MD21076NationalTechnicalInformationService5285PortRoyalRoadSpringfield,VA22100Availableelectronicallyat—2002-2114821ASystemsApproachtotheSolidLubricationofFoilAirBearingsforOil-FreeTurbomachineryChristopherDellaCorteandAntonioR.ZaldanaNationalAeronauticsandSpaceAdministrationGlennResearchCenterCleveland,Ohio44135KevinC.RadilU.S.ArmyResearchLaboratoryGlennResearchCenterCleveland,Ohio44135AbstractFoilairbearingsareself-actinghydrodynamicbearingswhichrelyuponsolidlubricantstoreducefrictionandminimizewearduringslidingwhichoccursatstart-upandshut-downwhensurfacespeedsaretoolowtoallowtheformationofahydrodynamicairfilm.Thissolidlubricationistypicallyaccomplishedbycoatingthenon-movingfoilsurfacewithathin,softpolymericfilm.Thefollowingpaperintroducesasystemsapproachinwhichthesolidlubricationisprovidedbyacombinationofselflubricatingshaftcoatingscoupledwithvariouswearresistantandlubricatingfoilcoatings.Theuseofmultiplematerials,eachprovidingdifferentfunctionsismodeledafteroil-lubricatedhydrodynamicsleevebearingtechnologywhichutilizesvariouscoatingsandsurfacetreatmentsinconjunctionwithoillubricantstoachieveoptimumperformance.Inthisstudy,roomtemperatureloadcapacitytestsareperformedonjournalfoilairbearingsoperatingat14,000rpm.Differentshaftandfoilcoatingtechnologiessuchasplasmasprayedcomposites,ceramic,polymerandinorganiclubricantcoatingsareevaluatedasfoilbearinglubricants.Theresultsindicatethatbearingperformanceisimprovedthroughtheindividualuseofthelubricantsandtreatmentstested.Further,combiningseveralsolidlubricantstogetheryieldedsynergisticallybetterresul