机械专业论文中英文对照

GearboxNoiseCorrelationwithTransmissionErrorandInfluenceofBearingPreloadDoctoralThesisinMachineDesignTRITA-MMK2008:19ISSN1400-1179ISRN/KTH/MMK/R-08/19-SEDepartmentofMachineDesignRoyalinstituteofTechnologySE10044Stockholm,Sweeden©MatsÅkerblom2008ABSTRACTThefiveappendedpapersalldealwithgearboxnoiseandvibration.Thefirstpaperpresentsareviewofpreviouslypublishedliteratureongearboxnoiseandvibration.Thesecondpaperdescribesatestrigthatwasspeciallydesignedandbuiltfornoisetestingofgears.Finiteelementanalysiswasusedtopredictthedynamicpropertiesofthetestrig,andexperimentalmodalanalysisofthegearboxhousingwasusedtoverifythetheoreticalpredictionsofnaturalfrequencies.Inthethirdpaper,theinfluenceofgearfinishingmethodandgeardeviationsongearboxnoiseisinvestigatedinwhatisprimarilyanexperimentalstudy.Eleventestgearpairsweremanufacturedusingthreedifferentfinishingmethods.Transmissionerror,whichisconsideredtobeanimportantexcitationmechanismforgearnoise,wasmeasuredaswellaspredicted.Thetestrigwasusedtomeasuregearboxnoiseandvibrationforthedifferenttestgearpairs.Themeasurednoiseandvibrationlevelswerecomparedwiththepredictedandmeasuredtransmissionerror.Mostoftheexperimentalresultscanbeinterpretedintermsofmeasuredandpredictedtransmissionerror.However,itdoesnotseempossibletoidentifyonesingleparameter,suchasmeasuredpeak-to-peaktransmissionerror,thatcanbedirectlyrelatedtomeasurednoiseandvibration.Themeasurementsalsoshowthatdisassemblyandreassemblyofthegearboxwiththesamegearpaircanchangethelevelsofmeasurednoiseandvibrationconsiderably.Thisfindingindicatesthatotherfactorsbesidesthegearsaffectgearnoise.Inthefourthpaper,theinfluenceofbearingendplayorpreloadongearboxnoiseandvibrationisinvestigated.Vibrationmeasurementswerecarriedoutattorquelevelsof140Nmand400Nm,with0.15mmand0mmbearingendplay,andwith0.15mmbearingpreload.Theresultsshowthatthebearingendplayandpreloadinfluencethegearboxvibrations.Withpreloadedbearings,thevibrationsincreaseatspeedsover2000rpmanddecreaseatspeedsbelow2000rpm,comparedwithbearingswithendplay.Finiteelementsimulationsshowthesametendenciesasthemeasurements.Thefifthpaperdescribeshowgearboxnoiseisreducedbyoptimizingthegeargeometryfordecreasedtransmissionerror.Robustnesswithrespecttogeardeviationsandvaryingtorqueisconsideredinordertofindageargeometrygivinglownoiseinanappropriatetorquerangedespitedeviationsfromthenominalgeometryduetomanufacturingtolerances.Staticanddynamictransmissionerror,noise,andhousingvibrationsweremeasured.Thecorrelationbetweendynamictransmissionerror,housingvibrationsandnoisewasinvestigatedinspeedsweepsfrom500to2500rpmatconstanttorque.Nocorrelationwasfoundbetweendynamictransmissionerrorandnoise.Staticloadedtransmissionerrorseemstobecorrelatedwiththeabilityofthegearpairtoexcitevibrationinthegearboxdynamicsystem.Keywords:gear,gearbox,noise,vibration,transmissionerror,bearingpreload.ACKNOWLEDGEMENTSThisworkwascarriedoutatVolvoConstructionEquipmentinEskilstunaandattheDepartmentofMachineDesignattheRoyalInstituteofTechnology(KTH)inStockholm.TheworkwasinitiatedbyProfessorJackSamuelsson(VolvoandKTH),ProfessorSörenAndersson(KTH),andDr.LarsBråthe(Volvo).ThefinancialsupportoftheSwedishFoundationforStrategicResearchandtheSwedishAgencyforInnovationSystems–VINNOVA–isgratefullyacknowledged.VolvoConstructionEquipmentisacknowledgedforgivingmetheopportunitytodevotetimetothiswork.ProfessorSörenAnderssonisgratefullyacknowledgedforexcellentguidanceandencouragement.IalsowishtoexpressmyappreciationtomycolleaguesattheDepartmentofMachineDesign,andespeciallytoDr.UlfSellgrenforperformingsimulationsandcontributingtothewritingofPaperD,andDr.StefanBjörklundforperformingsurfacefinishmeasurements.ThecontributionstoPaperCbyDr.MikaelPärssinenarehighlyappreciated.AllcontributionstothisworkbycolleaguesatVolvoaregratefullyappreciated.1INTRODUCTION1.1BackgroundNoiseisincreasinglyconsideredanenvironmentalissue.Thisbeliefisreflectedindemandsforlowernoiselevelsinmanyareasofsociety,includingtheworkingenvironment.Employeesspendalotoftimeinthisenvironmentandnoisecanleadnotonlytohearingimpairmentbutalsotodecreasedabilitytoconcentrate,resultingindecreasedproductivityandanincreasedriskofaccidents.Quality,too,hasbecomeincreasinglyimportant.Thequalityofaproductcanbedefinedasitsabilitytofulfillcustomers’demands.Thesedemandsoftenchangeovertime,andthebestcompetitorsinthemarketwillsetthestandard.Noiseconcernsarealsoexpressedinrelationtoconstructionmachinerysuchaswheelloadersandarticulatedhaulers.Thegearboxissometimesthedominantsourceofnoiseinthesemachines.Evenifthegearnoiseisnottheloudestsource,itspurehighfrequencytoneiseasilydistinguishedfromothernoisesourcesandisoftenperceivedasunpleasant.Thenoisecreatesanimpressionofpoorquality.Inordernottobeheard,gearnoisemustbeatleast15dBlowerthanothernoisesources,suchasenginenoise.1.2GearnoiseThisdissertationdealswiththekindofgearboxnoisethatisgeneratedbygearsunderload.Thisnoiseisoftenreferredtoas“gearwhine”andconsistsmainlyofpuretonesathighfrequenciescorrespondingtothegearmeshfrequencyandmultiplesthereof,whichare