汽车外文翻译

武汉科技大学第1页共7页DynamicModelingofVehicleGearboxforEarlyDetectionofLocalizedToothDefectNagwaAbd-elhalim,NabilHammed,MagdyAbdel-hady,ShawkiAbouel-SeoudandEidS.MohamedHelwanUniversityABSTRACTDynamicmodelingofthegearvibrationisausefultooltostudythevibrationresponseofagearedsystemundervariousgearparametersandoperatingconditions.Animprovedunderstandingofvibrationsignalisrequiredforearlydetectionofincipientgearfailuretoachievehighreliability.However,theaimofthisworkistomakeuseofa6-degree-of-freedomgeardynamicmodelincludinglocalizedtoothdefectforearlydetectionofgearfailure.Themodelconsistsofagearpair,twoshafts,twoinertiasrepresentingloadandprimemoverandbearings.Themodelincorporatestheeffectsoftime-varyingmeshstiffnessanddamping,backlash,excitationduetogearerrorsandmodifications.Theresultsindicatethatthesimulatedsignalshowsthatasthedefectsizeincreasestheamplitudeoftheaccelerationsignalincreases.Thecrestfactorandkurtosisvaluesofthesimulatedsignalincreaseasthefaultincreases.Thoughthecrestfactorandkurtosisvaluesgivesimilartrends,kurtosisisabetterindicatorascomparedtocrestfactor.KEYWORDS：Vibrationacceleration,systemmodeling,CrestFactor,Kurtosisvalue,defectsize,gearmeshing,pinion,gearNOMENCLATUREDJ，1J，2J，LJDrivemotor,pinion,gear,andloadmassmomentofinertiareplacementdecisioninasuitabletime.1m，1mMassesofpinionandgear.DTDrivingmotortorque.LTLoadtorque.武汉科技大学第2页共7页1FT，2FTFrictiontorque.1C，2CViscousdampingcoefficientofpinionandgearbearing.mCGearmeshdamping.mKGearmeshstiffness.1K，2KPinionandgearshaftstiffness.4Thevariancesquare.NThenumberofsamples.fThedefectwidthinfacedirection.hKUnitwidthHertzianstiffness.D，1，2，LAngulardisplacementofdrivemotor,pinion,gearandload.D，1，2，LAngularvelocityofdrivemotor,pinion,gearandload.D，1，2，LAngularaccelerationofdrivemotor,pinion,gearandload.INTRODUCTIONMuchofthepastresearchinthedynamicmodelingareahasconcludedthatanessentialsolutiontotheproblemistouseacomprehensivecomputermodelingandsimulationtooltoaidthetransmissiondesignandexperiments.Thesehavebeentwomajorobstaclestosuchanapproach:(1)Progressinunderstandingofthebasicgearrattlephenomenonhasbeenlimitedandslow.Thisisbecausetheengine-clutch-transmissionsysteminvolvessomestrongnonlinearitiesincludinggearbacklash,multi-valuedsprings,dryfriction,hysteresis,andthelike.(2)Thegearrattleisasystemproblemandnotonlyproblemofgearteeth.Eventhroughtheresearchandindustrialcommunityhasdiscussedthedifficultiesinvariesstagesoftheproblem,yetnothoroughframeworkcoveringtheentireinvestigationprocessofsuchproblemcurrentlyexists.Thisislargelydueothecomplexityofthepowertrainsystem,which武汉科技大学第3页共7页maymakeacomputeranalysistoolinefficient,inparticularlywhenmanydifferentelementsandclearancesareencountered(e.g.,gears,bearings,splines,synchronizers,andclutch)[1-3].Acomprehensivereviewofmathematicalmodelsusedingeardynamics,publishedbefore1986,hasbeenpresentedby[4].Inthisreview,geardynamicmodelswithoutdefectshavebeendiscussed.Inthepastfewyears,researchershavebeenworkingonthegeardynamicmodelswhichincludedefectslikepitting,spalling,crackandbrokentooth.Asingle-degree-of-freedommodelisusedwhichincludethee4ffectsofvariablemeshstiffness,damping,gearerrors,profilemodificationsandbacklash.Theeffectoftime-varyingmeshingdampingisalsoincludedinthiscase,Thesolutionisobtainedbyusingtheharmonicbalancemethods.Amethodofcalculatedtheoptimumprofilemodificationhasbeenproposedinordertoobtainazerovibrationofthegearpair[5-7].Theyalsoproposedalinearapproximateequationtomodethegearpairbyusingasingle-degree-offreedommodelGearrattlevibrationisaundesirablevibrationforpassengercarsandlighttrucksequippedwithmanualtransmissions.Unlikeautomatictransmissions,manualtransmissiondonothavethehighviscousdampinginherenttoahydrodynamictorqueconvertertosuppresstheimpactingofgearteethoscillatingthroughtheirgearbacklash.Thereforeasignificantlevelofvibrationanbeproducedbythegearrattleandtransmittedbothinsidethepassengercompartmentandoutsidethevehicle.Gearrattle,idleshake,andothervibrationgeneratedintheautomobiledrivelinehavebecomeanimportantconcerntoautomobilemanufacturesintheirpursuitofanincreasedlevelofperceptionofhighvibrationquality.Thetorsionalvibrationodrivelineisamajorsourceofgearrattlevibration.Themanualtransmissionproducesgearrattlebytheimpactingofgearoscillatingthroughtheirgearbacklash.Theimpactcollisionsaretransmittedtothetransmissionhousingviashaftsandbearings[8].Thegearpairdynamicmodelsincludingdefectshavebeendoneby[9].Thestudy武汉科技大学第4页共7页suggeststhatlittleworkhasbeendoneonmodelingofgearvibrationwithdefectandanaccurateanalyticalproceduretopredictgearvibrationsinthepresenceoflocaltoothfaulthasyettobedeveloped.However,thepurposeofthispaperistodevelopamultidegree-of-freedomnonlinearmodelforagearpairthatcanbeusedtostudytheeffectoflateral-torsionalvibrationcouplingonvibrationresponseinthepresenceoflocalizedtoothdefect.Atypicalfaultsignalisassumedtobeimpulsiveinnaturebecauseofthewayitisgenerated.Thesimulationartificiallyintroducedpittingingearsinmulti-stageautomotivetransmissiongearboxatdiffe