英文原文wear181-183(1995)868-875CaseStudyTheoreticalandpracticalaspectsofthewearofvanepumpsPartB.AnalysisofwearbehaviourintheVickersvanepumptestA.Kunza,R.Gellrichb,G.Beckmannc,E.BroszeitaaInstituteofMaterialScience,TechnicalUniversityDarmstadt,P.O.Box111452,64229Darmstadt,GcmbUniversityforTechnol08y,EconomyandSocialScienceZittau/Goditz,FacukyofMaihematics,P.O.Box264,02763ZutaucPetersiliensrr.2d,03044Cottbus,Received16August1994；acceptedlNovember1994AbstractThewearbehaviourofthevanepumpusedinthestandardmethodforindicatingthewearcharacteristicsofhydraulicfluids(ASTMD2882/DIN51389)hasbeenexaminedbycomparisonofthecalculatedwearandexperimentaldatausingalubricantwithoutanyadditives.InadditiontothetestseriesaccordingtoDIN51389,temperatureprofilesfromthepumphavebeenanalysedusingthebulktemperaturesofthecontactingcomponentsandthetemperatureinthelubricationgapasinputdataforthewearcalculation.CartridgesusedintestsaccordingtotheGennanstandardhavebeenexaminedextensivelybeforeandaftereachruntoobtaininputdataforthemathematicalmodelandtoJocatewear.Ananalysisofthe:tluidpropertiesandaninvestigationoftheinnuenceofwearparticlesinthehydrauliccircuitwereperformed.Theexperimentalresultswerecomparedwiththewearprediction,whichwasverifiedbytheagreementintermsofload,temporalwearprogressandlocalwear.Conclusionshavebeendrawnwithregardtothevalidityoftheloadassumptionsandwearcalculation,aswellastothelimitsofapplicabilityofthismethodinthepresenceofadditives.Keywords:Vanepumps；Hydraulicfluids；Wearprediction；Vickersvanepumptest1.IntroductionEffortstodevelopamathematicaltoolforwearpredictionwillnotbesuccessfulwithoutconsideringwearanditsphenomena.ThetaskofPartBofthisstudyistodescribetheanalysisofthewearbehaviourinthetribosysteminvestigatedandhowtheknowledgeachievedinfluencesthecalculations.Inputdataarederivedfromthemeasurementofmechanicalandgeometricalquantities,suchasthehardness,stylusprofilometry,fluidpropertiesandcontactradii.Thermalquantitiesarealsoessentialforthemodellingoflubrication.Thecalculationsmustbeverifiedwithweardata.BecausethetribosystemtobeanalysedisthevanepumpemployedintheVickersvanepumptest,whichhasbeeninuseforabout40years,severalweardatacanbeusedforcomparisonbetweencalculatedandmeasuredwearresults.Thesearethewearmasses0043-1648/95/$09.501995ElsevierScienceS.A.AllrightsreservedSSDI0043-1648(94)07087-3aftereachtcstrun,theprogrcssionofwearovertimeandthelocalwearontheinnerringsurface；incombination,theseenableacomprehensivestatementtobemadeonthevalidityofthemathematicalmodeldescribedinPartA.2.ExperimentsAlIVickersvanepumptestsdescribedwererunwiththesamefiuid.ItisareferenceoiloftheGermanRcscarchAssociationforTransmissionTechnique(FVA),andisamineraloilwithoutanyadditives(FVA3).Thusthedisturbinginfluencesofadditivescanbeexcluded.2./.InputdataforcalculationFig.1liststheinputandoutputquantitiesofthecalculations.MostoftheinputparameterswerederivedsurfaceprofilescontactforceandcontactvelocitydynamicviscositycontactradiihardnessvaluesYoungsmoduli,Poissonnumbersandlubricationgapspecificshearenergydensities*pressureexponentc,fviscosity；tlubricationgaptemperatureRoughsurfuceshaarenergyhypotelastoliubictionWm=f（t）Wf=f（）Fig.1.InputparametersandoutputquantitiesofthemathematicalmodelofPartA.Fig.2.CartridgeV104C:bushing,rotor,ring,bushing(abcwe),singlevane,pin(below).experimentallyfromallthecomponentsinvolvedbeforeandafteruseinthevanepumptests.Themechanicalcomponents,whichmustberenewedforeachtestrun,areshowninFig.2.Suchacartridgekitconsistsofarotor,ring,12vanes,bushingsandpin.Stylusprofilometrywasperformedontheinnersurfaceoftheringandonthetipsoftwovanesofthecartridgebeforeandaftereachtestrun.Earlierinvestigationshaveshownthattenparallelsectionsintheslidingdirectiononeachbodyaresufficienttodescribethesurfacetopographyinastatisticallysatisfactorymannerasatwo-dimensionalisotropicgaussianfieldaccordingtoRef.1.Onlythehighpassfilteredcomponentsoftheprofile(samplinglength,1.5mm；cuto五0.25mm)wereusedtodeterminethespectralmomentsmo,m2,m4andtheparameterofroughnessa.Accordingtothepartitionofthecontactforceintodifferentloadingzones,thetopographicdataofthenewsurfaceswereusedforzoneIV(lowlevelload,seePartA).Fortheotherzoneswithhighercontactforces,theprofilesofthesurfacesinthefinalconditionwereused,whichcorrespondstotheappearanceoftheinnerringsurfaceafterthetestruns.Thecontactforceandcontactvelocitywerecalculatedwithdifferentfluidpressuresanddynamicforcesactingonthevanes,revolutionnumberandringradu,whereasthechangeincontactradiuswasdocumentedwithaprofileprojector.Becausetheringradiiaremuchlargerthar)theradiiofthevanesinthecontactzone,thevanescanbeassumedtobehertziancylindersslidingalongaplanesurfaceandthecontactradiiaresimplytheradiiofthevanetips.Eachvanetipwastwicedrawnupatmagnificationsof100:1andthecontactradiiandcontactlocationsweremeasuredwithastenciLMeanvaluesofthecontactradiiweretransferredtothecalculation,whichisbased(similartothesurfaceprofiles)onvanesinbothconditions.TheVickershardnessHVlOwasmeasuredontheringandthreevanesofeachcartridge.Thishardnessleadstoabetterreproducibilitythanmicrohardnessvalues,butduetothelargeindenterload,itcouldonlybetakenafterthetestruns.Thereforechangesinhardnessvaluescouldnotberegistered.TheYoungsmoduli,Poissonnumbersanddensitiesofthering(AISI52100)andvanematerials(M2regC)arethefirstinputparametersintheshearenergyhypothesisandwereobtainedfromtheliterature.Thespecificshearenergydensities(seePartA)arematerialspecificconstants2l.Thefluidproperties(Fig.1)weremeasured,derivedfromtheliteratureorcalculated.Toobtainthedynamicviscosity,thedensitiesandkinematicviscositiesat20,40and800Cweremeasured.BecausethefluidisareferenceoilofFVA,thepressureexponentoftheviscosityisgiven3.Thetemperatureinthelubricationgapbetweentheringandvaneswasapprox:imatedbymeasurementsandcalculationsdescribedbelow.2.2.TemperatureprofilesTemperaturemeasurementwasperformedtoobtaininformationonhowaheatabletribometermustbecontrolledtosimulatethewearbehaviourofthevanepump.Thereforeshortenedtestrunswerecarriedoutuntiltemperatureswerestabilized.These10hvanepumptestsdeliveredtheinputdatafortheapproximationofthelubricationgaptemperatureinthering-vanecontact,aswellasadditionalwearmassestobecomparedwiththecalculatedprogressiortofwearintime.ThesamplingprinciplesforacquiringthetemperatureprofilesofthevanepumpareillustratedinFig.3.Thetemperatureofthelubricantinthegapbetweentheringandvaneswasestimatedtobeequaltoorgreaterthanthebulktemperatureontheinnerringsurface.Followingthefirstmainstatementofthermodynamics,theheatfluxQmpintothecomponentsofthepumpcanbederivedfromwiththefluidasthemediumforenergytransport.Qa,mpcanonlybetransferredtothecomponentsshowninFig.2.Forthesametemperaturedifferencesandmaterials,thisheatnUXcanbedividedintosinglecomponentfluxesaccordingtotherelationofmasses.ThederivedfluxQringistheheatwhichflowsinacertaintimeperiodinaradialdirectionthroughthering.Withtheknowntemperaturesontheouterringsurface,thebulktemperaturesontheinnerringsurfacecanbecalculatedandtransferredtothemodelofelastohydrodynamiclubrication.AlltestrunswiththeVickersvanepumpV104CwereperformedonatestrigaccordingtoASTMD2882/DIN51389,whichisshownschematicallyinFig.4.Thesestandardsdescribetheprocedurefortestingtheanti-wearpropertiesofhydraulicfiuids.TostarttheVickersvanepumptestaccordingtotheGermanstandard,thesystempressuremustberaisedinstepsof2MPaevery10min,beginningat2MPa,untilafinalpressureof14MPaisreached.Atthisstage,thefluidtemperaturemeasurcdbcforethepump(seeFig.4)mustbecontrolledtoguaranteeakinematicviscosityof13mm2S-iattheinletforevery:tluidtested.Theseconditionsmustbemaintaineduntilthetestisabortednormallyafter250hbyopeningthebypassofthepressurecontrolvalvebeforethemotorisstopped.Byacomparisonofthewearachievedontheringandvaneswiththeupperwearlimits,theanti-wearpropertiesofthefluidtestedcanbederived.ForperformingthetestssafelywiththefluidFVA3,itwaspreheatedt0400Candcirculatedinapressurefreeway.ThedamagewhichmayoccurduringthecriticalfirsthouroftherunscanbeavoidedusingTiNcoatedbushings4.Forcomparisonwiththeresultsderivedfromcomputation,thewearproducedintheserunsmustbedocumentedasamounts,bothlocallyandtemporally.Thewearmasseswerederivedfromtheweightdifferencesoftheringandvanesbeforeandaftereachrun.Theywereobtainedfromasequenceoffour250htestrunsandtw010hrunsfortemperaturemeasurement.Thelocallinearamountofwearwasdocum