汽车英语.docx
- 文档编号:27748085
- 上传时间:2023-07-04
- 格式:DOCX
- 页数:17
- 大小:534.99KB
汽车英语.docx
《汽车英语.docx》由会员分享,可在线阅读,更多相关《汽车英语.docx(17页珍藏版)》请在冰豆网上搜索。
汽车英语
AutomotiveBelts,Fittings,andHoses
INTRODUCTION
Ontheautomobile,especiallyontheengine,therearemanytypesofbelts,fittings,andhoses.BeltsareusedtoconnecttworotatingshaftstogetheiVarioustypesoffit-tingsarealsousedtoconnecttubesandhosestogether.Thischapterintroducesyoutothebasictypesofbelts,fit-tings,andhosesusedontoday’sautomobiles.Inaddition,serviceinformationisincludedthatshowshowtocheckandchangebelts,fittings,hoses,andtubing.
7.1AUTOMOTIVEBELTS
PURPOSEOFAUTOMOTIVEBELTS
Automotivebeltshavebeenusedforyearstoconnectonerotatingshafttoanother.Astechnologyimproves,stronger,moreflexiblebeltsweredevelopedfornewuses.Thebasicpurposeofusinganautomotivebeltistoconnecttwoshaftsthatarenotnecessarilynexttoeachother.Forexample,iftwoshaftsarenexttoeachotherandoneneedstobedrivenfromtheother,gearscouldbeused.Butwhentheshaftsarefartherapart,beltswillbeused.Inaddition,beltsarequietascomparedtogearsorchains.Theyarealsomuchlessexpensive.
Theuseofautomotivebeltsgivesflexibilitytowhererotatingshaftscanbeplaced.Ontoday’sautomotiveengine,beltsareusedtoturnalternators,powersteeringpumps,waterpumps,air-conditioningcompressors,andvariouspollutionequipment.Figure7-1showsanexampleofcommoncomponentsthatcanbedrivenbybeltsonthefrontofanautomotiveengine.
TYPESOFBELTS
Thereareseveraltypesofbeltsusedonautomotiveengin
Theexacttypeuseddependsonseveralconsideration&
Theseincludethefollowing:
(1)Thedistancebetweenthetworotatingshafts
(2)Thespeedofthebelts.
(3)Theloadonthehelts
FIGURE7-1Thebeltonthefrontofanautomotiveenginecanbeusedtodrivemanycomponentsandaccessories.
FIGURE7-3Dependingonthecarmanufacturer,fromonetofourbeltsmaybeusedtodrivevariouscomponents.
FIGURE7-4Beltsareconstructedwithrubber,FIGURE7-5Thiscoggedtimingbelt
fabric,andmetalcordsstrength.keepthecamshaftandcrankshaftthe
witheachother.
FIGURE7-2Varioustypesofbeltsareusedonautomofiveengines.
(1)Theneedfortimingorkeepingthetwoshaftsintimewitheachother
(2)Thedirectionofrotationbetweenthetwoshafts
(3)Thecostsoftheapplication
(4)Thelengthofservicerequired
CommonbeltsusedontheautomobileareshowninFigure7-2.TheconventionalVbeltisusedtodrivealternatorsonsomecars.Thealternatorneedstobedrivenbythecrankshaftoftheengine.TodothisasimpleVbeltmaybeused.NotethattheVbeltwillnotkeepthetworotatingshaftstimedtogether.Theremaybeslippagebetweenthetwo.TheVbeltisalow-costandeffectivewaytoconnecttworotatingshaftstogether.
ThecoggedVbelthasaseriesofribscutintoit.Theseribshaveatendencytoreduceslippagebetweentworotatingshaftsduringheavierloads.Theserpentinebeltiscorn-montodayonenginesthatrequireseveralrotatingshaftstobeturnedbyasinglebelt.Theserpentinebeltissonamedbecauseitcanbesnakedaroundseveralrotatingshafts.Theserpentinebelthasseveral(usuallyfourtoseven)angledgroovesinthebeltsurface.Thenumberofgroovesisdeterminedbythewidthandloadonthebelt.Thesegroovesincreasethesurfaceareaofthebeltsoslippageisreduced.Inaddition,theserpentinebeltiswideenoughsothatpulleyscanrunoneithersideofthebelt.
BELTSYSTEMS
Eachcarmanufacturermayuseadifferentbeltsystem.Figure7-3showsaone-,two-,three-,andfour-beltsystem.Dependingontheshaftsthatmustberotated,aserpentine/belt,Vbelt,orotherbeltmaybeused.Ineachcase,thecrankshaftisthedrivecomponent,whiletheothercornponentsarethedrivencomponents.Notethatsimilardiagramscanusuallybefoundintheservicemanualorunderthehoodofthecartohelptheservicetechnicianservicebeltsandpulleys...
CUSTOMERCONCERN:
AlternatorLightComesOn
Adriversaysthatwhiledrivinghomefromwork,thealternatorlightcameonsuddenly.Beingonlyafewblocksfromhome,thedrivercontinuedhomeandshutthecaroff.Whatcouldbetheproblem?
SOLUTION:
Oftenthealternatorbeltisdrivenfromthecrankshaft.Sometimesthisbeltisveryhardtosee.ltisaserpentine-typebeltand,ifnotcheckedforcracksandotherdamage,mayeasilybreak.Themostlikelycauseofthisproblemisthatthealternatorbeltbroke.Replacingthealternatorbeltwithanewonewilleasilyfixtheproblem.Inthisparticularcasetheair-conditioningcompressorbeltwillalsohavetoberemovedbecauseitridesontheouterendofthecrankshaftpulley.Thealternatorbeltridesonthecenterofthecrankshaftpulley.
BELTCONSTRUCTION
Variousmaterialsareusedtoensurethatautomotivebeltsarestrong.Allbeltsareconstructedofseveralmaterialsincludingrubber,fabric,andrubber-impregnatedfabric(rubberandfabricmixedtogether).Also,somebeltsarestrengthenedbyusingreinforcingfabricorsteelcordsin-sidethebelt.Thesematerialshelptoreducestretchandslippageunderheavierloadssuchasaircompressors.Fig-ure7-4showstheinternalmakeupofatypicalVbelt.Notethattherearefiberormetalreinforcementsections,rubber-impregnatedsections,andlaminatedfabricsections.
TIMINGBELTS
Inadditiontothebeltsjustmentioned,manyautomotiveenginesalsouseacoggedtimingbelt.Thepurposeofthecoggedtimingbeltistokeepthecamshaftexactlyintimewiththecrankshaft.Thisisimportantsothatthevalveskeepintimewiththepositionofthepistonduringnormaloperation.Figure7-5showsoneexampleofatimingbeltinplaceontheengine.Thecogsinthebeltactlikeachain,keepingthetworotatingshaftsfromslippingoutoftimewitheachother.
SERVICINGBELTS
Therearemanyimportantthingstoknowaboutservicing.belts.Forexample,whenorderingVbeltsitisveryimportanttoreplaceanexistingdamagedbeltwiththecorrectbelt.Vbeltstypicallyhaveacertainwidthandacertain
FIGURE7-6Alwaysmakesurethereplacementbeltisthecorrectsizerecommendedbythemanufacturer.
pitchorangleoftheV.Figure7-6showsthreeexamplesofVbeltsfittingintoapulley.NotethatthebeltistoonarrowindiagramA,toowideindiagramB,andthecorrectsizeindiagramC.
AVbeltmaybeidentifiedasA,B,C,orD.Theselettersindicatethewidthofthebelt.Aisthenarrowest;Disthewidest.Abeltmayalsobeidentifiedbyitslength.Forexample,A35meansanarrowbeltthatis35inchesinlength.Inaddition,vehiclemanufacturersalwaysprovidepartnumbersforspecificbeltapplications.
Wheninstallingserpentinebeltsalwaysmakesurethebeltisplacedcompletelyonthepulley.ItisveryeasytohavethebeltslightlyoffthepulleyasshowninFigure7-7.Inthetopdrawing,thebeltisinstalledcorrectly.Inthemiddledrawing,thebeltisinstalledtoofarintowardtheengine.Inthebottomdrawing,thebeltisinstalledtoofarout,awayfromtheengine.
FIGURE7-8AlwayscheckbeltsforcrackspeelingOiltearsmsingteethandsoOn.
FIGURE7-7Wheninstallingaserpentinebelt,besuretoinstaWitcorrectlyasshown.
Itisalwaysimportanttochecktheconditionofbeltsontheautomobileengine.Figure7-8showstypicaldamagetoloolcforonautomobilebelts.Problemstolookforin-dudethefollowing:
(1)Cracksinthebelt
(2)Oilsoakedintothebelt
(3)-Glazingcausedbyexcessiveslippage
(4)Tearsorsplits
(5)Peeling
(6)Outerwear
(7)Missingteeth
(8)Insidecracks
(9).Outsidecracks
Ifthereareanyvisiblecracksinthebelt,itshouldbereplacedimmediately.Infact,mostmanufacturersrecommendthatifonebeltneedsreplacement,allotherbeltsshouldbereplaced.Oftendamagetothebeltcanbebetterobservedifitisheldinbothhandsandthentwisted.Thetwistinghelpstoexposesomeofthepossibleproblemswithabelt.
ADJUSTINGBELTS
Somebeltsmayhaveatensiondevicethatkeepsthematthecorrecttension.Therearemanydesignsofbelt-tensiondevices.Inmostcases,thesetensionersworkagainstthebeltunderspringpressure.Thespring-loadedbelttensionerkeepsaconstantpressureonthebeltduringitsoperation.Itismostcommonlyusedonserpentinebelts.
Otherbelts,however,needtobeadjusted.Itisveryimportantforbeltstobeadjustedcorrectly.Ifabeltistooloose,itislikelytoslip.Thiscausesexcessivewearonthesidesofthebeltandoperatingproblemswiththedrivencomponent.Ontheotherhand,ifabeltistootight,itmaydamagebearingsthatareinthealternator,aircompressor,waterpump,andsoon.Whenabeltistootight,itputspressureonthebearingsinthesecomponents.Thiscausesthebearingstofailprematurely.
CUSTOMERCONCERN:
BeltSqueal
AdriverinaToyotasaysthatwhentheengineisaccelerated,thereisanoticeablesquealfromtheen-ginearea.Whatcouldbeapossibleproblem?
SOLUTION:
Whentheengineisaccelerated,thisputsmoreloadonthebelts.Ifabelthasbecomelooseovertime,itmaybegintosliponlyduringacceleration.Thesquealiscausedbythebeltslippingonthepulleys.Ifthisisthecase,readjustmentofthebeltsmaybenecessary.Alsocheckthebeltsforcracks,oil,peeling,andotherdamage.Theproblemwillmostlikelybesolvedbycorrectlyadjustingthetensiononallofthebelts.Rememberthattheaveragelifespanofabeltisabout5yearsor60,000miles,dependingontheexactapplication,ageofbelt,andsoon.
Belttensioncanbecheckedseveralways.Figure7-9showsonesimplewaytocheckthetensionofat,’picalbelt.Findthelon
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- 汽车 英语