汽车专业英语(原书作者宋红英)第三-七章PPT课件

1,UnitThree3.1DriveLine,.,2,Contents,Pre-questions,II.TextExplanation,III.Exercises,.,3,Howmanymainunitsdoesthedrivelineassemblyconsistof?Whatarethey？Thedrivelineassemblyconsistsofsixmainunits.Theyareclutch,transmission,driveshaft,finaldrive,differentialandthedrivingwheels.,Diagramofcarshowingclutchlocation,Pre-questions,.,4,Howdoesthedrivelinework?Thedrivelinecarriespowerfromtheenginecrankshafttothedrivingwheels,sothewheelsrotateandtheautomobilemoves.,Pre-questions,.,5,II.TextExplanation,Fig.3-1DriveLine1-clutch;2-transmission;3-universaljoint;4-finaldrive;5-differential;6-driveshaft,.,6,Thetypicaldrivelinecomprisesclutch,transmission,driveshaft,finaldrive,differentialandthedrivingwheels.译文：典型传动系统一般包括离合器、变速器、传动轴、主减速器、差速器和驱动轮等六部分。,II.TextExplanation,.,7,Whenyoulifttheclutchpedal,springsforcethepressureplateandclutchplateagainsttheflywheel.译文：当抬起踏板时，压缩弹簧将压盘和从动盘推向飞轮。,II.TextExplanation,.,8,Amanualtransmissionrequiresaclutchtoapplyandremovetheenginetorquetothetransmissioninputshaft.译文：手动变速器需要用离合器来把发动机转矩施加给变速器输入轴或从变速器输入轴撤消。,II.TextExplanation,.,9,Whenthecarisonstraightroad,theringgear,differentialcase,differentialpiniongears,andtwodifferentialsidegearsallturnasaunitwithoutanyrelativemotion.译文：汽车在直线行驶时，齿圈、差速器壳、差速器行星齿轮和两个差速器半轴齿轮作为一个整体运转，而无任何相对运动。,II.TextExplanation,.,10,Thedriveshaftsareusuallyhollowinordertoweighless,butofalargediametersothattheyarestrong.译文：传动轴通常是空心的以减轻重量，但直径比较大使它有足够的强度。,II.TextExplanation,.,11,III.Exercises,manualtransmissionreverseidlergearsgearratiosdriveshaftclutchplatedifferentialuniversaljointcoilspringpressureplatesynchronizer,手动变速器倒档齿轮齿轮齿数比传动轴离合器片差速器万向节螺旋弹簧压盘同步器,I.TranslatethefollowingexpressionsintoChinese.,.,12,III.Exercises,II.IdentifytheEnglishnamesofthedrivelineaccordingtothepicture.,1engine;2transmission;3driveshaft;4drivingwheel;5clutch;6universaljoint;7finaldrive,.,13,III.Exercises,III.Readthefollowingpassagecarefullyandfillintheblankswiththeproperformofthegivenwords.The(differential)systemispartoftherear-axle-housing(assembly),whichincludesthedifferential,(rearaxles),wheeland(bearings).Iftheautomobileweretobedrivenina(straight)linewithouthavingtomaketurns,thennodifferentialwouldbenecessary.However,whentheautomobileroundsaturn,the(outer)wheelmusttravelfartherthanthe(inner)wheel.Thedifferential(permits)thetworearwheelstorotate(different)amountswhentheautomobilegoesaroundaturn,whilestill(delivering)powertobothrearwheels.,.,14,III.Exercises,IV.TranslatethefollowingsentencesintoChinese.1.Althoughtherearemanytypesofclutch,thedrysingleplatetypeoftractionclutchisusedalmostexclusivelyinpassengercars.2.Thepressureondrivendiskfittedontothesplinedportionofshaftisprovidedbyspringsinstalledbetweenthehousingandpressuredrivingdisks.3.TheuniversaljointorU-jointsisusedtoconnectthediveshafttothetransmissionoutputshaftandthedifferentialpiniongearshaft.,.,15,1.虽然离合器的种类很多，但客车上采用最多的还是单片干式离合器。2.从动盘安装在传动轴的花键槽内，从动盘上的压力来自弹簧的弹力，这些弹簧安装在离合器壳和主动盘之间。3.万向节将动力输入轴、动力输出轴和差速器齿轮轴连接在一起。,.,16,V.TranslatethefollowingsentencesintoEnglish.1.如果快速运转的发动机突然与静止车辆的传动系相连接，就会产生强烈的冲击。2.离合器是一种用以连接和分离发动机和变速器的装置。3.装有自动变速器的汽车一般不需要离合器。,.,17,1.Itwillhaveastrongimpactwhenthespinningengineconnectsthestationarytransmission.2.Theclutchisadevicewhichisdesignedtoconnectanddisconnecttheengineandthetransmission.3.Thereisnotclutchwhentheautomobileequipautomatictransmission.,18,ThankYou!,19,UnitThree3.2Clutch,.,20,Contents,Pre-questions,II.TextExplanation,III.Exercises,.,21,Whatwillyoudowhenyoumovethecar？,Whatwillyoudowhenyouchangegears?,Startthecar,Releaseparkingbrakeandtheclutchpedalandpushdowngas,Firstgear,Neutralposition,Depresstheclutchpedal,secondgear,Releasetheclutchpedal,clutch,Depresstheclutchpedal,Firstgear,.,22,Whereistheclutchintheautomobile?,Diagramofcarshowingclutchlocation,A-engine,B-clutch,C-clutchpedal,D-manualtransmission,Pre-questions,.,23,Whatisthefunctionoftheclutch?Connectordisconnectthepowerfromtheenginetothedriveline.,Pre-questions,.,24,Howmanymainpartsdoestheclutchconsistof?,drivingmembers,drivenmembers,controlmechanisms,pressingmechanisms,Pre-questions,.,25,Inacar,youneedaclutchbecausetheenginespinsallthetime,butthecarswheelsdonot.spinspinvt.2-drivendisk;3-flywheel;4-clutchcover,.,30,Mostcarsequippedwithamanualtransmissionuseasingleclutchdisc,adiaphragmtypespring，apressureplateandclutchcoverassembly,aclutchreleasebearing,andaclutchreleasefork.singleclutchdisc单片离合器盘diaphragmtypespring膜片式弹簧pressureplate压盘clutchcover离合器盖releasebearing分离轴承releasefork分离叉,II.TextExplanation,.,31,drivendisk,.,32,Pressureplateandcover,cover,pressureplate,flywheel,.,33,releaseleversandreleaseyoke,releaselevers,releaseyoke,.,34,Theclutchhasaclutchdiscasitsmajorpart,andtheclutchdiscconsistsofacircularmetalplateattachedtoareinforcedsplinedhub.circulars:kjuladj.圆形的,环形的;循环的reinforceri:n,f:svt.增强;加强splinedhub花键毂译文：离合器有一个离合器盘作为主要部件，离合器盘包括一个圆形的金属盘，它与强化的花键毂连接在一起。attachedtoareinforcedsplinedhub是过去分词短语作状语修饰metalplate,II.TextExplanation,.,35,Thesplinedhubisfreetoslidelengthwisealongthesplinesofthetransmissioninputshaft.lengthwiselewaizadv.纵长地,纵向地译文：（离合器的）花键毂可以沿着变速器输入轴的花键自由滑动。,II.TextExplanation,.,36,Initsoperatingpositionintheengine/transmissionlinkup,theclutchdiscissandwichedbetweentheengineflywheelandclutchpressureplate.sandwichsnwidn.三明治vt.1把夹在之间2挤在中间译文：在发动机和变速器接合状态下，离合器盘被夹在发动机飞轮和离合器压盘之间。,II.TextExplanation,.,37,sandwich把一片火腿夹在两片面包之间就做成了火腿三明治。Tomakeahamsandwichyouputasliceofhambetweentwoslicesofbread.在公共汽车上,他被挤在两个胖女人中间。Hewassandwichedbetweentwoveryfatwomenonthebus.,.,38,Theclutchforkandlinkageprovidethemeansofconvertingtheup-and-downmovementoftheclutchpedaltotheback-and-forthmovementoftheclutchreleasebearingassembly.meansmi:nzn.方法,手段译文：离合器分离叉和连接件提供了将离合器踏板的上下运动转化为离合器分离轴承机构的前后运动的一种方法。,II.TextExplanation,.,39,means科学家们正在为发明一种能储存这种动力的方法而工作。Scientistsareworkingtodeviseameansofstoringthistypeofpower.,.,40,diaphragm-springtype,coil-pressure-springtype,.,41,III.Exercises,clutchreleaseforkdrivetraindrivingaxlespressureplatediaphragmtypesplinedhubcoilspringdiaphragmreleasefingersfrictiondisksengagementanddisengagement,分离叉传动系传动轴压盘膜片式花键毂螺旋弹簧膜片弹簧分离杠杆摩擦盘分离和接合,I.TranslatethefollowingexpressionsintoChinese.,.,42,II.IdentifytheEnglishnamesofclutchaccordingtothepicture.,1-frictiondisk2-spring3-splinedhub4-drivendisk5-pressureplate,6-locatingstuds7-diaphragmspring8-fulcrumring9-clutchcover,III.Exercises,.,43,III.Readthefollowingpassagecarefullyandfillintheblankswiththeproperformofthegivenwords.Theclutchreleasemechanismcanbeoperatedeither(mechanically)or(hydraulically).Themechanicallyoperatedreleasemechanismconsistsofa(pedal),a(returnspring),ashaftwithlever,arod,areleaseyoke(lever),areleaseyoke,areleaseballbearingwithsupportandaclutchreleasespring.,.,44,Whentheclutchpedalis(depressed),therodandshaftwithyokeshiftthereleasebearingandsupport(assembly).Thereleasebearingpressestheinnerendsofthereleaselevers,thepressure(driven)ismovedawayfromthe(plate)diskandtheclutchisdisengaged.To(engage)theclutch,thepedalisreleased,thereleasebearingandsupportassemblyisshiftedbackbythereturnspringthusreleasingthereleasingleverssothatthepressureplateisforcedbyitsspringstowardstheflywheeltoclampthedrivendiskandengagetheclutch.,.,45,IV.TranslatethefollowingsentencesintoChinese.1.Theclutchisadeviceusedtoprovidesmoothengagementanddisengagementofengineandtransmission.2.Everyvehiclehasanenginewhichprovidesthestartingpower,buttheenginedevelopslittlepowerortorqueatlowrpm,andmustgainspeedbeforeitmovesavehicle.3.Iftherapidlyrotatingenginewassuddenlyconnectedtothedrivelineofastationaryvehicle,theengagementwouldnotbesoft.,.,46,1.离合器是一种用以平稳连接和分离发动机和变速器的装置。2.每辆汽车都有一个提供动力的发动机，但是发动机在低速转动时几乎不产生动力或扭矩，而且发动机必须快速转动才能推动车辆前进。3.如果快速转动的发动机突然与静止车辆的驱动系统相连，这种接合就不会柔和。,.,47,V.TranslatethefollowingsentencesintoEnglish.1.经过离合器的动力输出主要是由与发动机曲轴相连的一个或多个驱动元件与一个或多个动力输入轴相连的驱动元件相接触形成的。2.沿压盘和离合器之间的圆周均匀分布的弹簧夹住压盘与飞轮之间的从动盘。3.汽车离合器在构造上都很相似，只是在压紧机构和分离机构的细节上稍有不同。,.,48,1.Poweroutputbytheclutchismainlydrivenbytheformationoftangencybetweenoneormoredrivecomponentsconnectedtotheenginecrankshaftandothersconnectedtothepowerinputshaft.2.Thespringevenlydistributedbetweenthecircumferenceofthepressureplateclampstheclutchdiscbetweentheflywheelandpressureplate.3.Allautomotiveclutchesareverysimilarinconstruction,onlydifferentinthedetailsofthepressure-plateassembliesandtheseparation.,49,ThankYou!,50,UnitThree3.3ManualTransmission,.,51,Contents,Pre-questions,II.TextExplanation,III.Exercises,.,52,Whatdoesthemanualtransmissionconsistof?Themanualtransmissionconsistsofahousing,aninputshaftandgear,anoutputshaftandgear,acountershaft,areversegear,aclusterofgearsandagearshiftmechanism.,Diagramofcarshowingclutchlocation,Pre-questions,.,53,Whatsthefunctionofthegearshiftmechanism?Thegearshiftmechanismisdesignedforengaginggears,settingthemneutralandengagingthereversespeed.,Pre-questions,.,54,Whereisthetransmissionlocatedinthecar?Whatdoesitactas?Thetransmissionislocatedinthemiddleoftheengineanddrivingwheels.Itactsaschangingthetorquetransmittedfromtheenginecrankshafttothepropellershaft,reversingthevehiclemovementanddisengagingtheenginefromthedrivelineforalongtimeatparkingorcoasting.,Pre-questions,.,55,II.TextExplanation,Fig.3-3ManualTransmission1-shiftmechanism;2-shiftforks;3-inputshaft;4-outputshaft;5-countershaft,.,56,Atransmissionisaspeedandpowerchangingdeviceinstalledatsomepointbetweentheengineanddrivingwheelsofthevehicle.译文：变速器是一个安装在汽车发动机和车轮间某个位置上的变换速度和动力的装置。,II.TextExplanation,.,57,Twotypesoftransmissionarethemanualandtheautomatic.译文：变速器可以分为手动式和自动式两种。,II.TextExplanation,.,58,Themanualtransmissionconsistsofahousing,aninputshaftandgear,anoutputshaftandgear,acountershaft,areversegear,aclusterofgearsandagearshiftmechanism.译文：手动式变速器由壳体、输入轴及齿轮、输出轴及齿轮、中间轴、倒档齿轮、齿轮组和换档装置组成。,II.TextExplanation,.,59,Theinputshaftismadeofsteelintegralwiththedrivinggearandtherim.译文：输入轴是钢制的，与驱动齿轮和齿圈制成一体。,II.TextExplanation,.,60,Thegearshiftmechanismconsistsofalever,shiftrails,shiftforks,retainers,locksandareversespeedsafetydevice.译文：齿轮换挡装置包括换档杆、拨叉轴、换档拨叉、保持架、换档锁和倒档安全装置。,II.TextExplanation,.,61,III.Exercises,parkingorcoastingneutralpositiontractiveresistancecountershaftreversegearsplinedportionoftheshaftintheboreofthecrankshaftreversespeedsafetydeviceshiftleversphericalbulb,停车或滑行空挡位牵引阻力中间轴反转齿轮轴的花键部分曲轴孔内倒档速度安全装置拨叉轴球形座孔,I.TranslatethefollowingexpressionsintoChinese.,.,62,III.Exercises,II.IdentifytheEnglishnamesofthemanualtransmissionaccordingtothepicture.,1-inputshaft;2-sleeve;3-outputshaft;4-reverseshaft;5-idlershaft;6-gear,.,63,III.Readthefollowingpassagecarefullyandfillintheblankswiththeproperformofthegivenwords.Asweknow,anenginecan(generate)onlylimitedtorqueatlowspeeds.Drivingconditionisverycomplicatedandthisrequiresthe(tractive)effortandspeedvaryinalargescope.Andwithoutsufficient(torque),movingaheavilyloadedvehiclefromastandingstartisimpossible.Inanyengine,thecrankshaftalwaysrotatesinthesame(direction).Iftheengine(transmits)itspowerdirectlytothedriveaxles,thewheelscouldbe(driven)onlyinonedirection.,.,64,Givenalevelroad,anautomobilewithoutatransmissioncouldbemadetomoveby(accelerating)theengineand(engaging)theclutch.However,astartundertheseconditionswouldbeslow,(noisy)anduncomfortable.Inaddition,itwouldplacea(tremendous)strainontheengineanddrivingpartsoftheautomobile.,.,65,IV.TranslatethefollowingsentencesintoChinese.Mostautomobilemanualtransmissionsallowthedrivertoselectanyforwardgearatanytime,butsome,suchasthosecommonlymountedonmotorcyclesandsometypesofracingcars,onlyallowthedrivertoselectthenext-higherornext-lowergearratio.Manualtransmissionsarecharacterizedbygearratiosthatareselectablebylockingselectedgearpairstotheoutputshaftinsidethetransmission.Contemporaryautomotivemanualtransmissionsaregenerallyavailablewithfourtosixforwardgearsandonereversegear,althoughmanualtransmissionshavebeenbuiltwithasfewastwoandasmanyaseightgears.,.,66,1.大多数汽车的手动变速器，允许司机随时选择任意前进档位，但也有例外，安装在摩托车和某些赛车上的手动变速器，只允许司机选择次高档或次低档。2.手动变速器的特点主要是：传动比的选择由安装在变速箱内部与输出轴相连的特定齿轮副确定。3.当代汽车手动变速器一般设置四至六个前进档和一个倒档，齿轮数一般有二至八个。,.,67,V.TranslatethefollowingsentencesintoEnglish.1.变速器是用来改变发动机曲轴送到驱动轴的转矩，完成倒车和在汽车长时间停车或滑行时分离发动机和动力传动系统的装置。2.变速器中间轴齿轮与主动齿轮是常啮合的。3.换档装置通过变换齿轮啮合，实现前进档、空档和倒档之间的变换。,.,68,1.Thetransmissionisdesignedforchangingthetorquetransmittedfromtheenginecrankshafttothepropellershaft,reversingthevehiclemovementanddisengagingtheenginefromthedrivelineforalongtimeatparkingorcoasting.2.Theidlershaftgearandthedrivinggearareinconstantmesh.3.Thegearshiftmechanismcompletestheconversionamongforward,neutralandreversepositiontochangegearing.,69,ThankYou!,70,UnitThree3.4AutomaticTransmission,.,71,Contents,Pre-questions,II.TextExplanation,III.Exercises,.,72,Howmanymainunitsistheautomatictransmissiondividedinto?Whatarethey?Theautomatictransmissionisdividedintofivemainunits.Theyareplanetarygearsets,thehydraulicsystem,sealsandgaskets,thetorqueconverter,thegovernorandthemodulatororthrottlecable.,Diagramofcarshowingclutchlocation,Pre-questions,.,73,Whatsthefunctionofplanetarygearsets?Theplanetarygearsetsprovidesoverdrive,reverse,forwardreduction,neutral,anddirectdrive.,Pre-questions,.,74,Whatsthefunctionofsealsandgasketsinautomatictransmission?Sealsandgasketsareusedtokeeptheoilwhereitissupposedtobeandpreventitfromleakingout.,Pre-questions,.,75,II.TextExplanation,Fig.3-4PlanetaryGearSystem1-planetgear;2-sungear;3-ringgear;4-planetarycarrier,.,76,Automatictransmissioniseasytomanipulateinacrowdedvehicle,theycangreatlyimprovetrafficsafetyandreliability.译文：自动变速器很容易操纵，在车辆拥挤时，可大大提高车辆行驶的安全性及可靠性。,II.TextExplanation,.,77,Thebasicplanetarygearsetconsistsofasungear,aringgearandtwoormoreplanetgears,allremaininginconstantmesh.译文：基本的行星齿轮装置由一个太阳轮、一个齿圈和两个或更多个行星齿轮组成，所有元件之间保持常啮合状态。,II.TextExplanation,.,78,Thetorqueconvertercanchangethetwistingmotionoftheenginecrankshaft.译文：液力变矩器可以改变发动机曲轴的扭转运动。,II.TextExplanation,.,79,Thehydraulicsystemisacomplexmazeofpassagesandtubesthatsendstransmissionfluidunderpressuretoallpartsofthetransmissionandtorqueconverter.译文：液压系统是个由复杂的通道和管道组成的迷宫，将一定压力的传动油送到变速器和液力变矩器内的所有零件上。,II.TextExplanation,.,80,Sealsandgasketstocontroltheflowofhydraulicfluidandtokeepitfromleakingout.译文：密封圈和密封垫用来控制传动液的流动并防止其泄漏。,II.TextExplanation,.,81,III.Exercises,one-wayclutchthrottlevalvetorqueconverterplanetarygearpumpwheelfuel-efficienttopgearhydrauliccontrolcircuitclutchpackplanetarygearset,单向离合器节气门液力变矩器行星齿轮泵轮燃油效率高速档液压控制管路离合器压盘行星齿轮组,I.TranslatethefollowingexpressionsintoChinese.,.,82,III.Exercises,II.IdentifytheEnglishnamesofplanetarygearsystemaccordingtothepicture.,1-planetarycarrier;2-sungear;3-planetgear;4-ringgear,.,83,III.Readthefollowingpassagecarefullyandfillintheblankswiththeproperformofthegivenwords.Thekeydifferencebetweena(manual)andan(automatic)transmissionisthatthemanualtransmissionlocksandunlocksdifferentsetsofgearstothe(output)shafttoachievethevariousgearratios,whileinanautomatictransmission,thesamesetofgearsproducesallofthedifferentgearratios.,.,84,Therearetwobasictypesofautomatictransmissionsbasedonwhetherthevehicleis(rear)wheeldriveor(front)wheeldrive.Onarearwheeldrivecar,thetransmissionisusually(mounted)tothebackoftheengine.Adriveshaftconnectstherearofthetransmissiontothe(finaldrive)whichislocatedintherear(axle)andisusedtosend(power)totherearwheels.Onafrontwheeldrivecar,thetransmissionisusuallycombinedwiththefinaldrivetoformwhatiscalleda(transaxle).Frontaxlesareconnecteddirectlytothetransaxleandprovidepowertothefrontwheels.,.,85,IV.TranslatethefollowingsentencesintoChinese.Anautomatictransmissionisanautomobilegearboxthatcanchangegearratiosautomaticallyasthevehiclemoves,freeingthedriverfromhavingtoshiftgearsmanually.Mostautomatictransmissionshaveasetselectionofpossiblegearranges,oftenwithaparkingpawlfeaturethatwilllocktheoutputshaftofthetransmission.Somemachineswithlimitedspeedrangesorfixedenginespeeds,suchassomeforklifttrucksandlawnmowers,onlyuseatorqueconvertertoprovideavariablegearingoftheenginetothewheels.,.,86,1.汽车行驶过程中，自动变速器可以自动改变传动比，驾驶员不用手动换挡。2.大多数自动变速器都具有传动比的选择范围，一般通过相应棘爪锁住变速器输出轴实现传动比的选择。3.一些发动机极限转速有限或转速稳定不变，例如一些叉车和割草机，这样就只能使用液力变矩器来实现发动机与驱动轮之间的传动比的变换。,.,87,V.TranslatethefollowingsentencesintoEnglish.1.自动变速器由液力变矩器、行星齿轮机构和液压操纵机构组成。2.液力变矩器的锁止离合器位于涡轮前端，由锁止活塞、减振盘和涡轮传动板等组成。3.单排行星齿轮机构通过固定不同的元件或改变联锁关系，可得出不同的传动状态。,.,88,1.Theautomatictransmissionconsistsofhydraulictorqueconverter,planetarygearsetsandhydrauliccontrolsets.2.Locatedinfrontoftheturbine,thelockingclutchofthehydraulictorqueconverterconsistsoflockingpiston,shockabsorbersandturbinedriveplate.3.Singleplanetarygearsetprovidesdifferenttransmissionformsbyrivetingdifferentcomponentsorchanginginterlockingrelationship.,89,ThankYou!,90,UnitThree3.5FinalDrive,.,91,Contents,Pre-questions,II.TextExplanation,III.Exercises,.,92,Whatsthefunctionofthefinaldrive?Thefinaldriveisthemaincomponentinthetransmissionlinetoreducespeedandincreasethetorque.Inthemeantimeitcanchangethedirectionoftorquewhenthemotorislongitudinal.,Diagramofcarshowingclutchlocation,Pre-questions,.,93,Howdoesthefinaldrivework?Thefinaldrivedependsonthegearwheelwithlessnumberofteethdrivingtheotheronewithmoreteethtoachievetheretardment.Andtheuseofconicalgearalsocanchangethedirectionoftorque.,Pre-questions,.,94,Howmanytypesdoesthefinaldrivehave?Whatarethey?Accordingtothenumberofsub-gearpairswhichtakepartintheretardment,thefinaldrivecanbedividedintosingle-stageandtwo-stagetype.Accordingtothenumberofsub-filesofthetransmissionratio,thefinaldrivecanbedividedintosinglespeedandtwo-speedtype.Accordingtothesub-structureofreductiongearpairs,thefinaldrivecanbedividedintothecylindricalgeartype,thebevelgeartype,thehypoidgeartypeandsoon.,Pre-questions,.,95,II.TextExplanation,Fig.3-5FinalDrive1-halfaxlegear;2-planetarygears;3-differentialhousing;4-ringgear;5-pinion,.,96,Itdependsonthegearwheelwithlessnumberofteethdrivingtheotheronewithmoreteethtoachieveretardment.译文：它是依靠齿数少的齿轮带动齿数多的齿轮来实现减速的。,II.TextExplanation,.,97,Inordertomeetdifferentrequirementsoftheapplication,thestructuresoffinaldrivearedifferent.译文：为满足不同的使用要求，主减速器的结构型式也是不同的。,II.TextExplanation,.,98,Apartfromsomemediumandheavyvehicleswhichrequireoflargetransmissionratiousingtwo-stagemainreducer,thegeneralmicro-,lightandsomemediumonesusuallyadoptthesingle-stagemainreducer.译文：除了一些要求大传动比的中