1 汽车专业英语课件-汽车基础知识部分-section 1汽车专业英语ppt课件-修改201702277 Chapter 3 5

复习,英文专业词汇离合器主要部件、类型手动变速器组成、主要部件名称传动轴、万向节、驱动桥翻译句子,学习内容,本次课学习内容、目标和重点难点,学习目标,难点重点,ClassificationofAutomaticTransmissionA/T,AMT,DCT,CVTconstructon,1.掌握A/T,AMT,DCT,CVT的结构特点，主要组成、各部件主要零件的英文名称2.提高翻译技巧，能较熟练翻译课文,1.重点是英文专业术语记忆2.难点是生词偏多、变速器原理,Chapter6Powertrain3.5Automaticgearbox,3.5.1NewWordsandPhrases,Chapter6Powertrain3.5Automaticgearbox,Chapter6Powertrain3.5Automaticgearbox,Chapter6Powertrain3.5Automaticgearbox,Chapter6Powertrain3.5Automaticgearbox,Differenttypesofautomaticgearboxesareused:semiautomaticandfullyautomatic.Semiautomaticgearboxes.Thepowerflowisinterruptedbyautomaticclutchdisengagementandcutinbyclutchengagement,e.g.automaticclutchsystem(ACS).Shiftingofgearstochangethegearratiosanddirectionofrotationisperformedmanuallybyoperatingashiftlever.Fullyautomaticgearboxes.Thepowerflowisautomaticallyinterruptedorcutinasrequired.Shiftingofgearstochangethegearratiosisperformedautomaticallybyelectro-hydraulicorelectro-pneumaticcontrol.Automatedmanualtransmission,ConvertertransmissionandCVTarefullyautomaticgearboxes.ThefeaturesofthegearboxesarelistedintheTable3-1.,Chapter6Powertrain3.5Automaticgearbox,3.5.2Text,Table3-1Featuresofthefullyautomaticgearboxes,1.Steppedautomatictransmissionwithhydrodynamicconverter(AT)-ConventionalautomatictransmissionTorqueconverter(Fig.3-11)servesasastartingclutchtofacilitatessmoothandcomfortabledrawingaway,transmitsandmultipliestheenginetorque,anddampsenginetorsionalvibrations.gearsystemsareusedtomultiplytorques,reducespeedsandreversesthedirectionofrotationforthereversegear.Mostautomaticsusetheplanetarygearsets(Fig.3-12).ThecommonlyusedplanetarygearsareRavigneauxsetandSimpsonset.Asimpleplanetary-gearsetcanalsobeconnectedtotheupstreamordownstreamofaRavigneauxsetorSimpsonset.Eithertheoutergearorthesungearmaybeheldstationary,providingmorethanonepossibletorquemultiplicationfactorforeachsetofgears.Also,ifallthreegearsareforcedtorotateatthesamespeed,thegearsetforms,ineffect,asolidshaft.,Chapter6Powertrain3.5Automaticgearbox,Clutchesandbands(Fig.3-13)areusedtoholdvariousportionsofthegearsetstothetransmissioncaseortransaxlecaseortotheshaftonwhichtheyaremounted.Shiftingisaccomplishedbychangingtheportionofeachplanetarygearsetwhichisheldtothecaseortotheshaft.Hydrauliccontrolsystemconsistsofoilpump,varioushydraulicregulatingvalves,shiftingvalves(Fig.3-14)andservos(plungersandcylinderswhichareusedtooperateshiftingelementssuchasclutchesandbands).Thehydraulicpressureusedtooperatetheservoscomesfromtheoilpump.Thisfluidischanneledtothevariousservosthroughtheshiftvalves,seeFigure3-14.,Chapter6Powertrain3.5Automaticgearbox,Chapter6Powertrain3.5Automaticgearbox,Theaccumulatorsareusedtocushiontheengagementoftheservos.Whenfluidpassesthroughtheaccumulatoronthewaytotheservo,itmustmovetheaccumulatorpistonagainstspringpressure,andthisactionsmoothesouttheactionoftheservo.Electroniccontrolsystems(Fig.3-15)areusedonautomatictransmissionsortransaxlestocontrolthelinepressure,converterlockup,shiftpointandshiftquality.,Chapter6Powertrain3.5Automaticgearbox,Fig.3-11Torqueconverter,Chapter6Powertrain3.5Automaticgearbox,Fig.3-12planetary-gearset,Chapter6Powertrain3.5Automaticgearbox,Fig.3-13bandbrake,Chapter6Powertrain3.5Automaticgearbox,Fig.3-14Ahydraulicsystem,Figure3-15Partlocationofaelectroniccontrolsystem,Chapter6Powertrain3.5Automaticgearbox,2.ContinuouslyvariabletransmissionThegearratiosofthegearboxarevariedcontinuouslyovertheentireworkingrangebytheprimaryandsecondaryV-pulleypairs.TheprimaryV-pulleyisdrivenbytheplanetarygearwhentheforwardorreversegearclutchisengaged.ItdrivesthesecondaryV-pulleyviaasteelbeltorachain.Variationofthegearratioisachievedbyaxialdisplacementofadiagonallyoppositepulleyhalfineachcase.Inthisway,theeffectivepulleyradius(rwlandrw2)arecontinuouslyvariedinopposition,i.e.biggerorsmaller(Figure.3-15).Displacementofthepulleyhalvesiseffectedbythetwopressure-controlledprimaryandsecondarycylinders.ThemaincomponentsandoperationofaCVTareshowninFigure3-16and3-17.,Chapter6Powertrain3.5Automaticgearbox,Figure3-15Thepulleyhalvesismovedtochangetheeffectivepulleyradius(rwlandrw2)continuously,Chapter6Powertrain3.5Automaticgearbox,Figure3-17componentsofaCVT,Chapter6Powertrain3.5Automaticgearbox,Figure3-18SchematicviewofaCVT,Chapter6Powertrain3.5Automaticgearbox,3.Automatedmanualtransmission(AMT)Automatedmanualtransmissionsarefullyautomatictransmissionsinwhichconventionalmanualtransmissionswithclutchesareautomaticallyshifted.IntheautomatedmanualtransmissionillustratedinFig.3-19,theclutchisactuatedandthegearsareshiftedbyelectrohydraulicmeans.Itisalsopossibletoshiftthegearsmanually,forexamplebyactuatingshiftpaddlesonthesteeringwheel.Maincontrolledvariablesfortheautomatedgearshiftsequenceare:drivingspeed,selectorleverposition,selecteddrivingprogramandaccelerator-pedalposition.TheECUevaluatestheinputsignalsfromthesensorsandusesstoredprogrammapstodeterminetheoutputsignalsforactivatingtheclutchslavecylinder,selectorcylinderandshiftcylinder.,Figure3-19SchematicviewofanAMT,Chapter6Powertrain3.5Automaticgearbox,4.Direct-shifttransmission(DSG)TheDSGisanautomatedtransmissioninwhicha6-or7-speedmanualtransmissionwithtwinclutchisautomaticallyshiftedbyelectricactuators.DSGisalsocalleddoubleclutchtransmission(DCT).Basicconstructionofa6-speedDSGisshowninFigure3-20andFigure3-21.Twinclutch.Thisconsistsof2wetclutchesC1andC2.ClutchC1isusedforstartingandisconnectedwiththegearwheelsmountedonthehollowshaftfortheoddgears(lst/3rd/5thgear)andthereversegear.ClutchC2isresponsiblefortheevengears(2nd/4th/6thgear).,Chapter6Powertrain3.5Automaticgearbox,Gearshiftprocess,e.g.from1stto2ndgear.Whilethevehi