汽車專業(yè)英語讀譯教程 第3版 課件 13-U8TA Clutches and Manual Transmissions

UNIT8

CLUTCHES,

MANUALTRANSMISSIONS

ANDDRIVELINE

TEXTA

ClutchesandManualTransmissions

PROFESSIONALENGLISHUNIT7

CLUTCHES,MANUALTRANSMISSIONS

ANDDRIVELINE

TEXTA

ClutchesandManualTransmissions

Clutches

ManualTransmission(M/T)

本次課學(xué)習(xí)內(nèi)容本次課學(xué)習(xí)目標(biāo)掌握離合器和手動變速器的有關(guān)英文專業(yè)詞匯能夠較好地用已知翻譯技巧進(jìn)行課文翻譯具有較高的閱讀速度NEWWORDStransaxle[?tr?nz'?ksl]n.變速驅(qū)動橋neutral['nju:tr?l]a.中立的,中性的；n.空檔throw-out['θrou'aut]n.拋開，斷開，次品，分離bronze[br?nz]n.青銅,銅像；a.青銅色的bushing['bu∫i?]n.軸襯,襯套，套管asbestos[?z'best?s]n.石棉woven['wouv?n]a.編成的，紡織的mold[mould]n.模子,鑄型；v.鑄[塑]造，模制rivet['rivit]n.鉚釘；v.鉚接，固定cup[k?p]n.杯；v.使成杯狀segment['segm?nt]n.段,節(jié),片，扇形cushion['ku∫?n]n.墊子,軟墊,襯墊，緩沖墊[器]revolve[ri'v?lv]v.(使)旋轉(zhuǎn),循環(huán)出現(xiàn)pinch[pint∫]v.夾緊，擠壓，節(jié)省seize[si:z]v.擠住，卡住，抓住,逮住,奪取overdrive['ouv?'draiv]n.超速傳動（常常簡寫為O/D）mileage['mailid]n.英里數(shù)，里程drop-forge['dr?p'f?:d]v.錘鍛,落錘鍛造spur[sp?:]n.正齒washer['w?∫?]n.墊圈,洗衣機(jī),洗碗機(jī)，洗滌器clash[kl?∫]v.(使)發(fā)出撞擊聲,猛撞,沖突smash[sm?∫]v.碰撞，猛撞literally['lit?r?li]ad.照字面意義,逐字地，確確實實地

PHRASESANDEXPRESSIONS

driveline傳動系統(tǒng)clutchdisc離合器從動盤pressureplate離合器壓盤throw-outbearing分離軸承releasebearing分離軸承pilotbearing導(dǎo)向軸承ballbearing球軸承dualmassflywheel雙質(zhì)量飛輪beconstructedof用…制造splinedhub花鍵轂

PHRASESANDEXPRESSIONS

releaselever分離桿gearratio傳動比reductiongear減速檔directdrivegear直接檔overdrivegear超速檔differentialgear差速器reversegear倒檔fuelmileage燃油經(jīng)濟(jì)性shiftingmechanism換檔機(jī)構(gòu)extensionhousing加長殼，后殼precisionmachinery精密機(jī)械

PHRASESANDEXPRESSIONS

endplay軸向間隙clustergear

齒輪組，塔齒輪thrustwasher止推墊片synchronizingmechanism同步機(jī)構(gòu)synchronizedgear同步器，同步機(jī)構(gòu)ClutchesThefunctionoftheclutchassemblyincarsandtruckswithmanualtransmissionsortransaxlesistoconnectordisconnecttheflowofpowerfromtheenginetothedriveline.Althoughtherearemanyvariationsinthedesignofclutches,allworkonthesamebasicprinciple.ClutchPurposeAclutchisamechanismdesignedtoconnectordisconnectpowerfromoneworkingparttoanother.Inavehicle,theclutchisusedtotransmitenginepowerandtodisengagetheengineandtransmissionwhenshiftinggears.Italsoallowstheenginetooperatewhenthevehicleisstoppedwithoutplacingthetransmissioninneutral(outofgear).

ClutchesandManualTransmissions

ClutchConstructionThemodernclutchisasingleplate,drydisc(seeFigure8-1).Itconsistsoffivemajorparts:flywheel,clutchdisc,pressureplateassembly,throw-outbearing,andclutchlinkage.Otherpartswhichmakeuptheclutchassemblyarethetransmissioninputshaftandclutchhousing.ClutchesandManualTransmissionsFigure8-1AtypicalclutchClutchesandManualTransmissionsClutchesandManualTransmissionsFlywheelInadditiontoprovidingabaseforthestarterringgear,theflywheelformsthefoundationonwhichtheotherclutchpartsareattached.Theflywheelusedwithmanualtransmissionsisthicktoenableittoabsorbalargeamountofheatgeneratedbyclutchoperation.Theclutchsideismachinedsmoothtoprovideafrictionsurface.Holesaredrilledintotheflywheeltoprovideameansofmountingtheclutchassembly.Aholeisusuallydrilleddirectlyintotherearofthecrankshaft.Thisholeallowsabearingtobeinstalledinthecenteroftheflywheel.Thebearinginthecenteroftheflywheelwillactasasupportfortheoutboardendofthetransmissioninputshaft.Itisreferredtoasapilotbearing.Thepilotbearingmaybeeitheraballbearingorabronzebushing.ClutchesandManualTransmissionsDualMassFlywheelAdualmassflywheelissometimesusedwithdieselengines.Tohelpabsorbenginepowerstrokepulsations,springsmountedinsidetheflywheelactasashockabsorbingunitwhentheflywheelsectionspartiallycompress,smoothingoutthepowerflow.Theyalsohelptoreducestressontheclutchandtransmissionparts.ClutchDiscTheclutchdiscisroundandconstructedofthin,highqualitysteelwithasplined(grooved)hubplacedinthecenter.Thehubsplinesengagesplinesonthetransmissioninputshaft.Theclutchdisccanmovebackandforthontheshaft,butwhenthediscisturned,theshaftmustturnalso.Bothsidesofitsouteredgearecoveredwithfrictionmaterial.Itisoftenmadeofasbestosorotherhightemperaturematerialandcopperwireseitherwovenormoldedtogether.Itisrivetedtothedisc.ClutchesandManualTransmissionsToassistinsmoothengagement,thediscouteredgesareoftensplitandeachpiececupped.Thefrictionmaterialisrivetedtothesesegments.Whenthedisciscompressed,thesecuppedsegmentsactasaspring-likecushion.PressurePlateTheclutchpressureplatediscisthesameineachtypeofpressureplateassembly.Itismadeofathickpieceofcastironformaximumheatabsorption.Itisroundandaboutthesamediameterastheclutchdisc.Onesideofthepressureplateismachinedsmooth.Thissidewillpresstheclutchdiscfacingareaagainsttheflywheel.Theoutersidehasvariousshapestofacilitateattachmentofspringsandreleasemechanisms.ClutchesandManualTransmissionsReleaseLeverOperatingMechanismThismechanismconsistsofaballbearingnormallyreferredtoasathrow-outbearingorreleasebearing.Thisbearingismountedonasleeveorcollarthatslidesbackandforthonahubthatisanintegralpartofthetransmissionfrontbearingretainer.Thethrow-outbearingisfilledwithgreaseatthefactoryanddoesnotneedserviceduringitsusefullife.Anothertypeofthrow-outbearingisthegraphitetype.Thisbearingemploysaringofgraphitetopressagainstasmoothplatefastenedtotheclutchlevers.Thethrow-outbearingsleeveismovedinandoutbyathrow-outforkorclutchfork.Thisforkisusuallypivotedonaballheadstud.Areturnspringpullstheforkawayfromthepressureplate.ClutchesandManualTransmissionsClutchOperationTheflywheel,clutchcover,releaselevers,andpressureplateallrevolveasasingleunit.Thetransmissioninputshaftandtheclutchdiscaresplinedtogether,forminganotherunit.Theonlytimetheclutchdiscwillturn(vehiclestandingstill)iswhenitispinchedbetweentheflywheelandpressureplate.Whenthereleaseleversdrawthepressureplateawayfromtheflywheel,theclutchdiscwillstandstillwhileeverythingelsecontinuestorevolve.Whenthepressureplatetravelsbacktowardtheflywheel,thediscisseizedandforcedtoturnthetransmissioninputshaft,Figure8-2.a)disengagedb)engagedFigure8-2ClutchoperationsimplifiedClutchesandManualTransmissionsManualTransmission(M/T)TransmissionGearRatiosThemodernmanualtransmissioncanprovidethedriverwithuptosixforwardgearratios.Thereductiongearsprovidegearratiosofapproximately3.5:1(statedas3.5to1)forthelowestgear,toabout1.5:1forthehighest.Thedirectdrivegearhasa1:1gearratio.Theoverdrivegearshaveagearratioofabout0.7:1.Byselectingoneoftheratios,itispossibletooperatethevehicleunderallnormalconditions.Inaddition,torqueismultipliedmorethroughthedifferentialgears.Ratiosvaryfromvehicletovehicle,dependingonenginehorsepowerandvehicleweight.Areversegearisalsoused.Thereverseratioisusuallyabout3:1.Thefive-speedtransmissionhasanoverdriveratio.Theoverdriveratioisincorporatedintonewertransmissionstoincreasefuelmileageandloweremissions.ClutchesandManualTransmissionsFigure8-3TherelativepositionsofthefourshaftsinthetransmissioncaseClutchesandManualTransmissionsClutchesandManualTransmissionsTransmissionConstructionAtypicaltransmissionconsistsofacase,fourshafts,bearings,gears,synchronizers,andashiftingmechanism.Figure8-3showstherelativepositionsofthefourshaftsandtheirgearsinthecase.TransmissionCaseThetransmissioncaseholdsthetransmissiongears,shafts,bearings,andwashers.Itisboltedtotherearoftheengine,ortotheclutchhousing.Manytransmissioncasesandclutchhousingsareone-pieceunits.Mosttransmissioncasesaremadeofcastironoraluminumandhaveaseparateextensionhousing,whichsupportstheoutputshaft.Thishousingmayalsocontainthespeedometergear.Therearenginemountisusuallyattachedtotheextensionhousing.ClutchesandManualTransmissionsTransmissionGearTransmissiongearsaremadeofhighqualitysteel,carefullyheat-treatedtoproducesmooth,hardsurfacegearteethwithasofter,butverytoughinterior[1].Theyaredrop-forged(machinehammeredintoshape)whileredhot.Theteethandothercriticalareasarecutonprecisionmachinery.Theteethontransmissiongearsarecutintospurandhelicalpatterns.Thehelicalgearissuperiorinthatitrunsmorequietlyandisstrongerbecausemoretoothareaisincontact[2].Helicalgearsmustbemountedfirmly,sincethereisatendencyforthemtoslideapartduetothespiralshape.Gearendplayintheclustergearandsomeothergearsandshaftsiscontrolledbytheuseofbronzeandsteelthrustwashers.Thesewashersareinstalledontheendofthegearshaftsbetweenthemovinggearsandthestationarytransmissioncase.ClutchesandManualTransmissionsTheremustbesomeclearancebetweenthegearteethtoallowforlubrication,expansionandpossiblesizeirregularity.Thisclearanceisverysmall(afewthousandthsofaninch).ClutchesandManualTransmissionsSynchronizingMechanismOncethevehicleisinmotion,thedrivelinewillturntheoutputshaftcontinuously.Asaresult,