会员注册 | 登录 | 微信快捷登录 支付宝快捷登录 QQ登录 微博登录 | 帮助中心 人人文库renrendoc.com美如初恋!
站内搜索 百度文库

热门搜索: 直缝焊接机 矿井提升机 循环球式转向器图纸 机器人手爪发展史 管道机器人dwg 动平衡试验台设计

外文翻译--卡车和货车.doc外文翻译--卡车和货车.doc -- 5 元

宽屏显示 收藏 分享

页面加载中... ... 广告 0 秒后退出

资源预览需要最新版本的Flash Player支持。
您尚未安装或版本过低,建议您

附录1英文原文TrucksandWagons3.1GeneralTrucksarehaulingunitswhich,becauseoftheirhighspeedswhenoperatingonsuitableroads,havehighcapacitiesandproviderelativelylowhaulingcosts.Theyprovideahighdegreeofflexibility,asthenumberinservicemaybeincreasedordecreasedeasilytopermitmodificationsinthetotalhaulingcapacityofafleet.Mosttrucksmaybeoperatedoveranyhaulroadforwhichthesurfaceissufficientlyfirmandsmoothandonwhichthegradesarenotexcessivelysteep.Someunitsnowinusearedesignatedasoffhighwaytrucksbecausetheirsizesandtotalloadsarelargerthanthatarepermittedonhighways.Thesetrucksareusedforhaulingmaterialsonlargeprojects,wherethesizesandcostsarejustified.Trucksmaybeclassifiedaccordingtoagreatmanyfactors,includingthefollowing1.Sizeandtypeofenginegasoline,diesel,butane,propane.2.Numberofgears.3.Kindofdrivetwowheel,fourwheel,sixwheel,etc.4.Numberofwheelsandaxlesandarrangementofdrivingwheels.5.Methodofdumpingtheloadreardump,sidedump.6.classofmaterialhauledearth,rock,coal,ore,etc.7.Capacity,intonorcubicmetercubicyards.8.Methodofdumpingtheloadforreardumps,hydraulicorcable.Iftruckaretobepurchasedforgeneralmaterialhauling,thepurchasershouldselectunitsthatareadaptabletothepurposesforwhichtheywillbeused.However,iftruckaretobeusedonagivenprojectforagivenpurpose,thepurchasershouldselecttrucksthatmostnearlyfittherequirementoftheproject.1.RearDumpTrucks2.Reardumptrucksaresuitableforuseinhaulingmanytypesofmaterials.Theshapeofthebody,suchastheextentofsharpangles,corners,andthecontouroftherear,throughwhichthematerialsmustflowduringdumping,willaffecttheeaseordifficultyofdumpingj41.Thebodiesoftruckthatwillbeusedtohaulwetclayandsimilarmaterialsshouldbefreeofsharpanglesandcorners.Drysandandgravelwillfloweasilyfromalmostanyshapeofbody.Ifquarryrockistobehauled,bodiesshouldbeshallowwithslopingsideboards.2.BottomDumpWagonsIfunitsaretobeusedtohaulmaterials,suchassand,gravel,reasonabledryearth,coal,etc.whichfloweasily,theuseofbottomdumpwagonswillreducethetimerequiredtounloadtheunits.Suchunitsareparticularlysuitableforusewherethematerialsaredistributedinlayersonafilloraredischargedthroughgrizzliesintohoppers.Whendischargingtheloadontofills,thewagonscandumptheirloadswhilemoving.Whendischargingthroughgrizzlies,theywillneedtostopforonlyafewseconds.Therapidrateofdischargingtheloadgivesthesewagonsatimeadvantageoverreardumptrucks.Asthedoorsthroughwhichtheseunitsdischargetheirloadhavelimitedopenings,difficultiesmaybeexperiencedindischargingsuchmaterialsaswet,stickyclay,especiallyiftheyareinlargelumps.Thesewagonsaresatisfactoryhaulingunitsonprojectssuchasearthendams,levees,highwaysandairports,wherelargequantitiesofmaterialsaretobetransportedandhaulroadscanbekeptinreasonablygoodcondition.Theymaybeloadedbypowershovels,draglines,orportablebeltloaders.3.CapacitiesofTrucksandWagonsThereareatleastthreemethodsofexpressingthecapacitiesoftrucksandwagonsbytheloadwhichitwillcarry,expressedintonsbyitsstruckvolumeandbyitsheapedvolume。thelattertwoexpressedincubicmeterorcubicyards.Thestruckcapacityofatruckisthevolumeofmaterialwhichitwillhaulwhenitisfilledtothetopofthesides,withnomaterialabovethesides.Theheapedcapacityisthevolumeofmaterialwhichitwillhaulwhentheloadisheapedabovethesides.Thecapacityshouldbeexpressedincubicmeters.Whilethetruckcapacityremainsfixedforanygivenunit,buttheheapedcapacitywillvarywiththeheighttowhichthematerialmayextendabovethesidesandwiththelengthandwidthofthebody.Wetearthorsandyclaymaybehauledwithaslopeof11,whiledrysandorgravelmaynotpermitaslopegreaterthan31.Inordertodeterminetheprobableheapedcapacityofaunit,itisnecessarytoknowthestruckcapacity,thelengthandwidthofthebody,andtheslopeatwhichthematerialwillremainstablewhiletheunitismoving.Smoothhaulroadswillpermitalargeheapedcapacitythanroughhaulroads.Becauseofvariationsintheheapingcapacitiesofunitsitmaybebettertocomparethemonthebasisoftheirstruckcapacities.Inaneeventthecapacitiesshouldbedeterminedorcomparedinarealisticmanner.Theweightcapacitymaylimitthevolumeoftheloadwhenaunitisusedtohaulheavymaterial,suchasironore.However,whenthespecificgravityofthematerialissuchthatthesafeloadisnotexceeded,aunitmaybefilledtoitsheapedcapacity.Insomeinstancesitispossibletoaddsideboardstoincreasethedepthofthebodyofatruckorwagon,therebypermittingittohaulalargerload.Thispracticeprobablywillincreasethehourlycostofoperatingaunit,becauseofhigherfuelconsumption,reducedtirelife.morefrequentfailuresofparts,suchasaxles,gears,brakes,andclutches,andhighermaintenancecosts.However,ifthevalueoftheextramaterialhauledisgreaterthanthetotalincreaseinthecostofoperatingavehicle,theoverloadingisjustified.Inconsideringhaulinglargervolumesofmaterials,themaximumsafeloadsonthetiresshouldbecheckedtopreventexcessiveoverloading,whichmightresultinconsiderablelosttimeduetotirefailures.3.2DesignandPrincipalMechanismsofTracksTheprincipalmechanismsofmostmoderntruckshaveaverysimilardesignandlayout.Eachtruckconsistsessentiallyofthreecomponentpartsengine,chassisandbody.Trucksarepoweredmainlybycarburetorordieselengines.Thebodyisintendedtocarryloadorpeople.Thedriverscabisusuallyseparatedfromthebody,anditsformanddesignconformtothepurposethetruckistoserve.Thechassiscarriestheengine,body,transmission.runninggearandcontrols.Thepowertrainofatruckisacombinationofmechanismsfortransmittingthetorquedevelopedbytheenginecrankshafttothedrivingwheels.ThepowertrainofamassproducedtruckFig.31incorporatesthefollowingmainmechanisms,thepurposeanddesignofmostofwhichdonotdifferinprinciplefromthecorrespondingmechanismsintractorsengine1,clutch2,transmissionbox3,universaljointshaft4,finaldrive8withdifferential5anddrivingwheels6withaxleshafts7.Whentheresistancemetbythetruckincreases,forexampleinclimbinguphill,thetransmissionboxisusedtoincreasethetorqueattheexpenseofalowerspeed6j.Thetransmissionboxesoftrucksandtractorsaredesignedsimilarlyandthefunctionsperformedbytheengineclutcharethesame.Theuniversaljointshafttransmitstorquefromthetransmissionboxtothefinaldrive.Thetransmissionboxisattachedrigidlytothetruckframe,whilethefinaldriveandtherearaxleareconnectedtotheframebymeansofspring.Asthetyresofthetruckhitbumpsintheroadtherearaxleoscillatescontinuously,changingtheanglebetweenthetransmissionboxandfinaldriveshafts.Forthisreason,themainpurposeoftheuniversaljointshaftisthetransmissionoftorquebetweenshaftincludedatdifferentangles.Thefinaldriveamplifiesthetorqueandtransmitsitfromthelongitudinaluniversaljointshafttothedrivingaxleshaftsandthewheels.Thefinaldrivesintrucksandtractorsservethesamepurpose.Thedifferentialusedintruckfinaldrivesallowsthedrivingwheelstorotateatdifferentspeeds,whichisnecessarywhenthetruckturnsorgoesoverunevenroadandtherightandleftwheelstraveldifferentdistancesduringthesametime.InatruckmovingstraightonasmoothroadthismayOccurwhentheradiioftherightandleftwheelsareunequal.Phenomenoniscausedbyanunequalpressureinthetyres,nonuniformwearofthetyresordifferentloadactingonthewheels.Therunninggearofatruckcomprisesaframesupportingthebodyandallothermechanisms,aswellasthefrontandrearaxles.springsforanelasticsuspensionoftheaxlestotheframe,andairtyredwheels.Thespringsandtyrestransmitloadfromtheframetotheroad,andatthesametimedampjerksandshockswhenthetruckhitsbumpsintheroad.Theresultantoscillationsaredampedbyspecialshockabsorbers.Thesteeringcontrolincludessteeringgear,brakesystem,enginecontrolandpowertraincontro1.Thesteeringgearisusedtochangethedirectionofmotionbyturningthewheels.Whicharelinkedwiththesteeringwheelbyasystemofleversandrods.Thebrakesystemcontributestowardssafetyandslowsdownatruckgoingdownaslope.Thebrakesaremountedonthetruckwheelsandsometimesontheuniversaljointshaft.Thebrakesareconnectedwiththebrakepedalorleverbymeansofmechanical,hydraulicorairoperateddevices.Enginecontrolallowsachangeinthenumberofrevolutionstobeeffectedinaccordancewiththedemands,whilethepowertraincontrolboilsdowntoengaginganddisengagingtheclutchandchangingspeeds.Effortstoimprovethepropertiesoftrucksoradaptthemforspecialpurposescontinuouslychangeandimproveboththeindividualelementsandthegenerallayout.Forallthat,anddespitethegreatdiversityoftypes,alltrucksconsistessentiallyofthemainelementsdescribedabove.3.3PowerTrainofTrucks1、ClutchInconformitywithitsfunction,theclutchshouldsmoothlyengageandjustassmoothlyandrapidlycomeoutofengagement.Drydiskclutchesaremostwidespread.Thedesignoftheclutchpressureassemblysubdividesallclutchesintospringloadedandovercentreclutches.Intheformertypethepressuredisksareconstantlycompressedbyspringsandtheclutchcanbedisengagedbydepressingthepedalwhich,overcomingthespringtension,willdrawapartthefrictionsurfaces.Assoonasthepedalisreleasedthediskswillbeagainbroughtincontactbythesprings.Inthelattertypethedrivinganddrivendisksarepressedtogetherbyalevermechanismandtheclutchleverorpedalneednotbeconstantlydepresse.Effortisappliedtotheleveronlyduringengagementordisengagement.Theseclutchesareemployedmainlyingeneralpurposecrawleragriculturaltractorswhereshorttimestoppagesareaffectedbydisengagingtheclutch,becausethetransmissiongearcannotbechangedwhilerunningandaresomewhatdifficulttoengageanddisengageinviewoftheirlargesize.Springloadedclutchesareusedpredominantlyintrucks.Fig.32illustratesoneofthemostwidespreadandsimpletypesofsinglediskspringloadedclutch.Clutchshaft13transmissionboxdrivingshaftismountedintwoballbearings,itsfrontendrestingintheflywheelopeningandtherearendinthefrontwallofthetransmissionbox.Housing3isattachedtoengineflywheel1.Thepressureondrivendisk2fittedontothesplintedportionofshaft13isprovidedbysprings5installedbetweenthehousingandpressuredrivingdisk4.Threereleaselevers11aremountedonspindles12attachedtohousing3.Thepressuredisk,rotatingtogetherwiththehousingandflywheel,canbeshiftedtoeithersideofthedrivendisktoincreasetheforceoffrictionbetweenthedrivinganddrivendisks.Theclutchreleasemechanismoperatesasfollows.Whensleeve10movestowardstheflywheel,thrustbearing6pressesagainsttheendsofthereleaselevers11whichtherebyturnontheiraxlesandseparatethepressuredrivingdiskfromtheflywheel,releasingthedrivendiskfromtheactionofthespring.Thesleeveisshiftedbyfork9,connectedwithpedal7throughasystemofarmsandrods.Whenthepedalisreleased,sleeve10returnstoitsinitialpositionandthepressurediskisshiftedbythespringstowardstheflywheel.Althoughfrictionclutchesofthistypereduceimpactloadswhenthegearsarebeingchangedinthetransmissionbox,frequentengagementandcontinuousslippingtendtoheatthemexcessively.Insometrucksthepowertrainincorporatesaturboclutch,wherethehydrodynamiceffectofcirculatingfluidisutilizedtotransmittorque.Thispreventstheclutchfromheatingandwearingasaresultofcontinuousslippingandmakesitpossibletoreducethenumberofswitchingoveroperationsinthetransmissionbox.
编号:201311171551316989    大小:13.06MB    格式:DOC    上传时间:2013-11-17
  【编辑】
5
关 键 词:
教育专区 外文翻译 精品文档 外文翻译
温馨提示:
1: 本站所有资源如无特殊说明,都需要本地电脑安装OFFICE2007和PDF阅读器。图纸软件为CAD,CAXA,PROE,UG,SolidWorks等.压缩文件请下载最新的WinRAR软件解压。
2: 本站的文档不包含任何第三方提供的附件图纸等,如果需要附件,请联系上传者。文件的所有权益归上传用户所有。
3.本站RAR压缩包中若带图纸,网页内容里面会有图纸预览,若没有图纸预览就没有图纸。
4. 未经权益所有人同意不得将文件中的内容挪作商业或盈利用途。
5. 人人文库网仅提供交流平台,并不能对任何下载内容负责。
6. 下载文件中如有侵权或不适当内容,请与我们联系,我们立即纠正。
7. 本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。
  人人文库网所有资源均是用户自行上传分享,仅供网友学习交流,未经上传用户书面授权,请勿作他用。
0条评论

还可以输入200字符

暂无评论,赶快抢占沙发吧。

当前资源信息

4.0
 
(2人评价)
浏览:33次
英文资料库上传于2013-11-17

官方联系方式

客服手机:17625900360   
2:不支持迅雷下载,请使用浏览器下载   
3:不支持QQ浏览器下载,请用其他浏览器   
4:下载后的文档和图纸-无水印   
5:文档经过压缩,下载后原文更清晰   

相关资源

相关资源

相关搜索

教育专区   外文翻译   精品文档   外文翻译  
关于我们 - 网站声明 - 网站地图 - 友情链接 - 网站客服客服 - 联系我们
copyright@ 2015-2017 人人文库网网站版权所有
苏ICP备12009002号-5