發(fā)動機英文翻譯

“中南林業(yè)科技大學”熱能與動力工程專業(yè)“不落的星塵”全力打造，華麗的一個金幣，傳說中的物美價廉發(fā)動機英文翻譯、內(nèi)燃機英文翻譯、汽車英文翻譯、熱動英文翻譯由于上傳失敗，現(xiàn)將兩幅插圖放在另一個文檔中期待各位的指正，謝謝！分割線割了煩惱畢業(yè)愉快工作愉快……(本文來自《汽車專業(yè)英語》/陳勇、邊明遠主編)).TheEngine’sSstemTheengineisanimportantpartoftheautomobile;itactsastheheartofaperson,whichprovidesthepowerthatthecarsneedtorunontheroad.AlltheautomotiveenginestodayaretheInternalCombustionEngines(ICEs)becausethefuelisburntinsidetheircylindersandtheenergyisprovided.ICEsarethoseheatenginesthatburntheirfuelinsidetheenginecylinder.InICEs,thechemicalenergystoredintheirfuelconvertedintoheatenergyduringtheburningpartoftheiroperation.Theheatenergyisconvertedintomechanicalenergybytheexpansionofgasesagainstthepistonattachedtocrankshaftthatcanrotate.Theenginesthatburnpetrolareknownaspetrolengine.OthertypesofICEsburnheavieroils,ofthesetypesthedieselenginehascomeintothewidestuse.Dieselandpetrolengineshavethesamemechanicalparts,exceptthatdieselcomponentsaregenerallystrongerandheavier.Bothenginesareinternalcombustionengines,buttheyhavedifferentfuelsystemandusedifferentfuels.Withadiesel,onlyairentersthecylinderduringtheintakestroke.Apetrolenginetakesinanair-fuelmixture.Followingaresomegeneralcomparisonsbetweendieselandpetrolengines:Inadiesel,thefuelisinjectedintothecylinderasafinespraynearthetopofthecompressionstroke.Withapetrolengine,thefuelisinjectedintotheexhaustportsatthestartoftheinductionstroke.Ignitioninadieselisbythehightemperaturefromthehighlycompressedair.Apetrolengineneedsasparkforignition.Dieselenginesgenerallyoperateatlowerenginerpmthanpetrolengines.Dieselenginesusedistillateforfuel,whichislessvolatilethanpetrol.Thedesignofdieselenginesmakesthemnoisierthanpetrolenginesandtheyhaveauniquedieselknock.Smalldieselengines,aswellaspetrolengines,areusedinpassengercarsandlightcommercialvehicles.Largerdieselenginesareusedinallheavycommercialvehicles,earthmovingequipment,andfarmmachinery..EngineConfigurationsThetermengineconfigurationreferstothewaythatthecylindersofanenginearearranged.Thecylinderscanbein-line,oratanangle(V-type).Withinthesethreebasicarrangements,thereareanumberofvariations.In-lineengineWithin-lineengines,thecylindersarearrangedinastraightline,onebehindtheother.Mostin-lineengineshavetheircylindersvertical,butsomeareslanted.Thatis,theengineistiltedatanangletoreducetheoverallheight.Theseenginesaresometimesreferredtoasslantedengines.Somein-lineengineshavetheircylindershorizontal,sothattheengineismoreorlessonitsside.Thisreducestheoverallheightoftheengine.Thisarrangementis＜插圖位置〉usedmainlyinlargercommercialvehicleswiththeenginemountedunderpartofthecab.Themechanicalarrangementofafour-cylinderin-lineforapassengercarisshowninFig.1-9.Thecut-awayviewinFig.1-10enablesthevariouspartstobeidentified.HorizontallyopposedengineThisarrangementhasitscylindersarrangedintwoflatblankswiththecrankshaftbetweenthem.Theengineshownhasashortrigidcrankshaftwithfivebearings.Ahorizontallyopposedenginehasevenfiringimpulsesandgoodbalance.Movementofapistonindirectionisopposedbymovementofapistonintheoppositedirection.Horizontallyopposedengines,withtheirflatdesign,givetheenginealowheightandalsohelptokeepthecenterofgravityofthevehiclelow.Alowcenterofgravitygivesthevehiclestability.V-typeenginesWithV-typeengines,thecylindersarearrangedintwoblanksatanangle.Thisreducesthelengthoftheengineandmakesitmorecompact.Thisalsoreducesthelengthofthecrankshaft,whichcanbedesignedtobemorerigidthanalongshaft..TheEngineAssemblyandComponentsThecompleteengineassemblyconsistsofthemechanicalcomponentsthatmakeuptheengineitselfandalsoanumberofassociatedsystems.Thesearethesystemsthatareneededtostarttheengineandalsotocontrolitandkeepitrunning.Themechanicalpartsoftheengineassemblycanbebrokendownintoanumberofsub-assemblies,orgroupsofassociatedcomponents,althoughtheseareusuallyreferredtomerelyasassemblies,forexample,cylinder-headassemblyandpistonassembly.Somepartsofanengineareinternal,otherpartsareexternal,thisillustrationidentifiesanumberofexternalparts.Thevariouscomponentsofanengineareassembledtogetherduringmanufacturedandmostofthesearesecuredbymeansofbolts,nutsandothertypesoffasteners.Somepartsareinternalandothersareattachedtotheoutsideoftheengine.Thecylinderblockisthelargestpartofengine.Theotherpartsareeitherfittedintotheblockorattachedtoit.Asitsnamesuggests,itisbasicallyablockofcastmetal,usuallycastiron,butitcanbealuminumalloywithcastironorsteelliners.Aluminumisusedtoreducetheweight.Thecylinderblockhasaccuratelyboredcylinderstotakethepistons.Thelowerpartoftheblockisknownasthecrankcaseandthishasbearingsthatcarrythecrankshaft.Thewater-jacketsthatsurroundthecylindersarefilledwithcoolant.Thetopofthecylinderblockhasamachinedsurfaceforthecylinderheadandthebottomofthecylinderblockismachinedtoprovideamountingfortheoilpan,orsump.Thecylinderscanbearrangedintheblocksothattheyareinline,asshown,ortheycanbesetatangle(V-typeengine).Thecrankshaftismountedinbearingsinthelowerpartofthecylinderblock(thecrankcase).Theconnectingrodsconnectthepistonstothecrankshaft,whichisrotatedbythepowerstrokesofthepistonswhentheengineisrunning.Theup-and-down,orreciprocating,motionofthepistonsischangedtorotarymotionbythecombinationactionoftheconnectingrodsandthecranksofthecrankshaft.Thetermcrankshaftcomesfromthewordcranked,whichalsomeansbent.Itisashaftwithanumberofcranksorbends.Within-lineengines,thereacrankforeachcylinder,butwithsomeV-typeengines,thereisonlyonecrankforeachpairofcylinders.Theflywheelisaheavycastironwheelattachedtotherearofthecrankshaft.Itreducesenginevibrationsbysmoothingoutthepowerimpulsesofthepistons.Theflywheelabsorbsenergyduringthepowerstrokeandgivesupenergyduringtheotherstrokesandthishelpstokeeptheenginerunningsmoothly.Aringgearfittedtotherimoftheflywheelsothattheenginecanberotatedbythestarterpinionwhenstartingtheengine.Withautomatictransmissions,adriveplateandtorqueconvertertaketheplaceoftheflywheelandperformthesamefunctionsasaflywheel,asfarastherunningoftheengineisconcerned.Thepistonhasgroovesthatcarrythepistonringsandtheseprovideasealbetweenthepistonandthecylinderwall.Compressionringsareusedasagassealandtheoilringisusedtopreventexcessoilfromfindingitswayuppastthepistonintothecombustionchamber.Theconnectingrodhasaremovablecapandasplitbearingatitslowerendwhereitisconnectedtothecrankshaft.Itsupperhasapistonpinthatprovidesawrist-typeofactionwiththepiston.Becauseofitsaction,thepistonpinissometimesreferredtoasawristpin.Thecylinderheadismadeofcastaluminumalloy.Itisboltedtothetopofthecylinderblocksothatitenclosesthecylinders.Ithascombustionchambersabovethecylindersinwhichtheair-fuelmixtureisburnt.Cylinderheadscanbemadeofcastiron,whichismoreresistanttocorrosion,butaluminumalloyisusedforpetrolenginesbecauseithasadvantagesofbetterheattransferandlighterweight.Thecylinderheadhasintakeportsandexhaustports.Theintakevalvesopentheintakeportstoadmitthefuelchargeintothecylinderduringtheintakestroke.Theexhaustvalvesopentheexhaustportstoallowtheburntgasestoleavethecylinderfollowingtheexhauststroke.Thecamshaftandthevalvemechanismareusedtoopenandclosethevalvesatthecorrecttime.Thecamshaftisdrivenfromthecrankshaftathalfthecrankshaftspeed.Thevalvecover,alsocalledthecylinder-headcover,isfittedtothetopofthecylinderhead.Thisenclosesthevalvemechanism.Anadditionalcoverontopoftheenginecoverstheignitioncoils.Thiscylinder-headarrangement,forafour-cylinderengine,hastwocamshaftsandsixteenvalves.Otherfour-cylinderenginescanhavetwocamshaftsandtwelvevalves,oronecamshaftandeightvalves.Thetimingbeltandpulleysdrivethecamshaftathalfthecrankshaftspeed(enginespeed).Atootheddrivebeltisoftenused,butgearsandchainsarealsoused-insomeinstancesabeltandchainarebothused.Onsomeengines,thetimingchainisusedtodrivetheoilpump.Ondieselengines,atimingchainoratiminggearisusedtodrivetheinjectionpumpaswellasthecamshaft.Theoilpan,orsump,holdstheoilfortheenginelubricatingsystem.Theoilpanismadeofsteelthathasbeenpressedtoshape.Otheroilpansaremadeofaluminumalloythathasbeencasttoshape.Theoilpanisboltedtotheundersideoftheenginesothatitclosesoffthecrankcase.Onlytheendsofthecrankshaftthatextendbeyondthecylinderblockareexposed.Variousformsofgasketsandsealsareusedbetweenthesurfaceswherethepartsareboltedtogether.Someoftheseareusedtosealagainstoil,someagainstcoolantandsomeagainstheatandpressure.Someprovideasealonflatsurfaces,othersealagainstrotatingshafts.Aswellasthelargerpartsofanengine,therearenumeroussmallparts.Theseincludebolts,washers,retainers,springandbracketswhichgotomakeupthemechanicalcomponentsoftheengine..EngineSystemsTheenginesystemsthatenabletheenginetostartandtocontinuetooperateareasfollows:Startingsystem;Fuelsystem;Ignitionsystem;Coolingsystem;Lubricatingsystem;Intakesystem;Exhaustsystem;Chargingsystem;Engine’selectroniccontrolsystem.Thesearethesystemsforpetrolengines.Dieselengineshavesimilarsystemsexceptforthefuelandignitionsystems.Somepartsofthesystemsarebuiltintotheengine,somepartsareattachedtotheengineandotherpartsarelocatedonthebodypanelsintheenginecompartment.StartingsystemThestarterisusedtorotatetheengineduringstarting.Itconsistsofanelectricmotorandadrive.Thedrivehasasmallpinionthatmesheswiththeringgearontheflywheelduringstarting.Thebatterysuppliestheelectricalenergytooperatethestarterandrotatetheengineuntilitfiresandrunsonitsown.FuelsystemThesearefourbasictypesoffuelsystems:carburetorsystemsforpetrolengines,fuelinjectionsystemsforpetrolengines,gasfuelsystems(LPGorNGV),anddieselinjectionsystems.Allthesesystemsoperateindifferentways,buttheyallhavesomewheretostorefuel(afueltankoracylinder)andawayofsupplyingtheenginewiththefuel.Theyalsohaveawayofsupplyingairandfuelmixedinthecorrectproportionsothatitcanbeeffectivelyburninthecombustionchambers.IgnitionsystemPetrolenginesandenginesoperatingongasrequireanignitionsystem.Thisisneededtoprovidethesparksthatfirethechargesinthecombustionchambers.Forthisreason,petrolenginesaresometimesreferredtoasspark-ignitionengines.Thisdistinguishesthemfromthemdieselenginesthatdonotneedasparkbecausetheyusecompressionignition.Combustioninadieseloccurswhenthefuelissprayedintothecombustionchamber.Theairinthecylinderisathightemperaturefrombeingcompressed-highenoughtoignitethefuelthatissprayedfromtheinjector.CoolingsystemAconsiderableamountofheatisproducedinanenginebytheburningair-fuelmixture.Someoftheheatisusedtodousefulwork,someistransferredtootherpartsoftheengineandsomeiscarriedawaywithexhaustgases.However,thereisstillenoughheattocausedamageunlessitisremoved.Thisisstillthefunctionofthecoolingsystem,whichremovesaboutone-thirdoftheheatthatisproduced.Thecoolingsystemdoesnotjustremoveheat;itmaintainstheengineatadesirableoperatingtemperature.Inaliquid-cooledengine,thisisdonebycirculatingcoolantthroughthewater-jackets.Inanair-cooledengine,coolingisbyairovercoolingfins.LubricatingsystemTheengine-lubricatingsystemconsistsofanoilpump,areliefvalveandafilter;alsopipes,passagesanddrillingsinvariouspartsofenginethroughwhichtheoilcanflow.Aquantityofoilisheldintheoilpan.Fromthis,oilistakenbytheoilpumpandcirculatedthroughouttheenginebeforereturningtotheoilpan.Theoillubricatesallthemovingpartsandthisisnotonlyreducesfriction,butitpreventswearanddamage.Theoilpumpisdrivendirectlybythecrankshaft.Thissystemhasanoilcooler,locatedatthefiltermountingunderthefilter.IntakesystemInpetrolenginewithelectronicfuelinjection,theintakesystemincludestheaircleaner,thethrottlevalveassemblyandtheintakemanifold.Theintakesystemprovidescleanairandcarriesitintotheenginethroughtheintakemanifold.Nozzlesofthefuelinjectorssprayfuelintotheairpassingfromtheintakemanifoldintotheintakeports.Withcarburetorfuelsystems,amixtureofairandfueliscarriedfromthecarburetor,throughtheintakemanifoldandintotheenginethroughtheintakeports.Forenginesthatoperateongas,amixtureofairandgasiscarriedintotheenginebytheintakemanifold.Inpetrolengineswithfuelinjection,andindieselengines,cleanaironlyisprovidedbytheintakesystem.ExhaustsystemTheexhaustsystemcarriestheburntgasesawayfromtheengineandalsoreducesnoise.Thesystemconsistsoftheexhaustmanifold,exhaustpipes,acatalyticconverterandamuffler.Arrangementsvarywithdifferentengines,theremaybemorethanonemufflerandmorethanonecatalyticconverter.EnginesthatrunonLeadReplacementPetrol(LRP)donothaveacatalyticconverter,neitherdodieselengines.ChargingsystemThealternator,whichisdrivenbytheengine,convertsmechanicalenergytoelectricalenergy.Thebatterysuppliesenergyforthestarter,theignitionsystemandelectricfuelpumpduringthestartingperiod(petrolengine),butoncetheengineisrunning,thealternatorsuppliesalltheelectricalenergy.Italsorechargesthebatterytoreplacetheenergyusedduringstarting.Engine’selectroniccontrolsystemTheengine’selectroniccontrolsystemconsistsofsensors,acontrolunitandactuators.Thecontrolunitreceivessignalsfromthesensorsandthensendssignalstovariousactuators.Therearesensorsontheengine,intheintakesystemandintheexhaustsystem.Theinjectorsareactuatorsthatadjustthesprayoffuel.Therearealsoactuatorsintheignitionsystemthatadvanceandretardthespark.Thesearejusttwoexamplesofwhereelectroniccontrolisused..EngineOperationDuringthedownwardmotionofthepiston,theair-fuelmixtureissuckedfromthecarburetorintothecylinder.Duringtheupwardmotionthemixtureiscompressedbythepistoninthecylinderandignitedbyanelectricspark.Whenthemixtureisburnedinthecylinder,theresultingheatcausesthegasestoexpandwhichexertpressureonthecylinderwallsandonthepiston.Thepiston,beingmovable,ispusheddownwardbythispressuretothefulllengthofitsstroke.Thepressureexertedonthepistonistransmittedthroughtheconnectingrodtothecrankshaftthatismadetorevolve.Thecrankshaftturnsthroughone-halfofarevolutionasthepistonmovesdownward.Aflywheelattachedtothecrankshaftstoresupenergy.Themomentumoftheflywheelcarriesthepistonthroughthebalanceofitsmotionuntilitreceivesanotherpowerimpulse.Theprocessisrepeatedoverandoveragain,thecrankshaftisturningcontinuouslyandtheengineisrunning.Theeventsthatarerepeatedmakeupthecycleoftheengine.Thenumberofstokesofthepistonrequiredtocompletethecyclevarieswiththetypeofengine.Inmodernvehicles,thecycleisextendedthroughfourstrokeofthepistonortworevolutionsofthecrankshaft.Thisiscalledafour-strokecycleengine.Intwostrokecycleengines,thecycleiscompletedintwostrokesofthepistonoronerevolutionofthecrankshaft.Inthefour-strokecycleengine,thefourstrokesarenamedsuction,compression,power,andexhaustinaccordancewiththeoperationofthecyclewhichoccurduringeachparticularstroke.Suctionstroke:duringsuctionstroke,thepistonismoveddownwardbythecrankshaft,whichisrevolvedeitherbythemomentumoftheflywheelorbythepowergeneratedbytheelectricstartingmotor.Theinletvalveremainsopenandtheexhaustvalveisclosedduringthisstroke.Thedownwardmovementofthepistonsucksair-fuelmixtureinthecylinderfromthecarburetorthroughtheopeninletvalve.Herethefuelispetrolmixedwithair,brokenupintoamist,andpartiallyvaporizedinthecarburetor.Compressionstroke:duringcompressionstroke,thepistonmovesupward,thuscompressingthecharge.Ignitionandmuchofthecompressionalsotakeplaceduringthisstroke.Theheatproducedbythecompressionmakesmorehomogeneousmixtureofairandpetrolinsidethecylinder.Theheatmakesthepetroleasiertoburn,whilethecompressionforcesitintoclosercombinationwiththeair.Themixture,undercompression,isignitedbythesparkproducedbyasparkplug,andthecombustionisoverhalf-completedwhenthepistonisatTopDead-Centre(TDC).Boththeinletandexhaustvalvesremainclosedduringthecompressionstroke.Working,powerorexpansionstroke:theexpansionofthegasesduetotheheatofcombustionexertsapressureonthecylinderandpiston.Underthisimpulsethepistonmovesdownwardthusdoingusefulwork.Boththevalvesremainclosedduringthisstroke.Exhauststroke:duringthisstroke,theinletvalveremainsclosedandtheexhaustvalveopens.Thegreaterpartoftheburntgasesescapesbecauseoftheirownexpansion.Thepistonmovesupwardandpushestheremaininggasesoutoftheopenexhaustvalve.Onlyasmallquantityofexhaustgasesremainsintheclearancespacewhichwilldilutethefreshincomingcharge.Thus,inthistypeofengine,fourstrokesofthepistonarerequiredtocompletethecycle,andthefourstrokesmaketworevolutionsofthecrankshaft.Theoperationsarerepeatedoverandoveragaininrunningtheengine.發(fā)動機的組成發(fā)動機是汽車的重要組成部分，它為汽車提供行駛的動力，對汽車而言它就像心臟對人一樣重要。現(xiàn)今所有的汽車發(fā)動機都是內(nèi)燃機（ICEs），這種發(fā)動機的燃料在氣缸內(nèi)燃燒，燃燒產(chǎn)生的能量直接提供給發(fā)動機。內(nèi)燃機是將燃料在發(fā)動機氣缸里面燃燒的熱機。在內(nèi)燃機運轉(zhuǎn)過程中，儲存在燃料中的化學能通過燃燒轉(zhuǎn)變?yōu)闊崮?。?nèi)燃機的活塞通過連桿連接在可以旋轉(zhuǎn)的曲軸上，熱能使氣體膨脹推動活塞轉(zhuǎn)變?yōu)闄C械能。燃燒汽油的發(fā)動機叫汽油機。其它形式的內(nèi)燃機燃燒重油，其中以柴油機的應(yīng)用最為廣泛。柴油機與汽油機具有相似的構(gòu)造，其區(qū)別在于柴油機比較笨重。這兩種發(fā)動機都是內(nèi)燃機，但是兩者具有不同的燃燒系統(tǒng)，并且使用不同的燃料。對于柴油機，在進氣行程中只有空氣進入氣缸。而對于汽油機，在進氣行程中是吸入空氣和燃料的混合物。通常，柴油機和汽油機具有以下區(qū)別：在柴油機中，燃料是在壓縮行程末期以很好的霧狀形態(tài)噴入氣缸。而在汽油機中，燃料在進氣行程初期被吸入到排氣孔附近。在柴油機中，燃料是被高壓空氣的高溫點燃的。而在汽油機中，燃料需要火花才能點燃。柴油機正常運轉(zhuǎn)時的轉(zhuǎn)速通常比汽油機的低。柴油機一般使用比汽油揮發(fā)性小的蒸餾物作為燃料。柴油機的構(gòu)造使其噪聲比汽油機大，并且會產(chǎn)生特有的爆震。小型柴油機和汽油機一樣，都被應(yīng)用于乘用車和輕型商用車上。大型柴油機被應(yīng)用于所有的重型商用車、工程用車以及農(nóng)用機械。1.發(fā)動機的類型發(fā)動機的類型是指發(fā)動機氣缸的排列形式。氣缸可以排列在一條直線上，可以對置排列，還可以呈一定角度排列（V型）。以這三種排列形式為基礎(chǔ)，又發(fā)展了多種排列形式。直列式發(fā)動機顧名思義，直列式發(fā)動機中各氣缸排成一直列，一個緊鄰一個，在一條直線上。大多數(shù)直列式發(fā)動機其氣缸都是垂直的，但也有一些是傾斜的。氣缸傾斜設(shè)置可以降低發(fā)動機的整體高度，這類發(fā)動機有時叫做傾斜發(fā)動機。有些直列式發(fā)動機的氣缸是水平放置的，這類發(fā)動機的橫向尺寸會比較大，不過這樣可以降低發(fā)動機整高。這類發(fā)動機主要用于大型商用車上，其發(fā)動機架位于駕駛室底部。如圖1-9顯示的是轎車用直列四缸發(fā)動機的構(gòu)造。圖1-10是側(cè)面剖視圖，可以看到更多零部件，便于分別。水平對置式發(fā)動機這種排列方式將氣缸布置在曲軸兩側(cè)的平面上，曲軸是剛性較大的短軸，其上有五個軸承。水平對置式發(fā)動機有相當好的輸出脈沖和平穩(wěn)性?；钊倪\動方向與對面的活塞運動方向相反。由于水平對置式發(fā)動機的平面布置，大大降低了發(fā)動機的高度，有利于降低＜插圖位置〉汽車的重心，這樣可以使汽車更穩(wěn)定。V型發(fā)動機在V型發(fā)動機中，氣缸被布置在兩個成一定角度的平面上。這樣減小了發(fā)動機的長度，使其更緊湊。同時也減小了曲軸的長度，使之剛性增強。2.發(fā)動機的構(gòu)造及其零部件發(fā)動機總成由許多構(gòu)成它本身的零部件和相關(guān)系統(tǒng)組成。這些系統(tǒng)是發(fā)動機起動和維持運轉(zhuǎn)所必需的。組成發(fā)動機的各個零部件可以分成一系列分總成或者相關(guān)的組件，通常也叫它們總成，例如缸蓋總成、活塞總成。有些零部件在發(fā)動機里面，有些在外面，本文的插圖展示了一些發(fā)動機外面的零部件。發(fā)動機各種各樣的零部件通過螺栓、螺母和其它的緊固件裝配在一起。有些零部件安裝在發(fā)動機里面，還有些固定在外面。機體是發(fā)動機中最大的零件。其它零部件都是安裝或連接在機體上的。顧名思義，機體是一塊金屬鑄體，通常是鑄鐵，但也可以是鑄鋁合金或者鑄鋼。機體中精確加工了氣缸，可以使活塞在里面運動。機體的下部是曲軸箱，里面有安裝曲軸的軸承。在氣缸周圍的水套里充滿了冷卻液。機體頂部是一個機械加工面，用來裝配氣缸蓋，底部裝配油底殼或機油箱。在機體中氣缸可以布置成一列直線，也可以成一定角度布置（V型發(fā)動機）。曲軸安裝在機體下部的軸承上（曲軸箱里面）?；钊颓S之間用連桿連接，發(fā)動機運轉(zhuǎn)時曲軸靠活塞的做功行程旋轉(zhuǎn)?；钊耐鶑?fù)運動通過連桿和曲軸上曲柄的共同作用轉(zhuǎn)變?yōu)樾D(zhuǎn)運動。曲軸這個詞源于英文單詞“cranked”，它是轉(zhuǎn)動曲柄的意思，包含有彎曲的意思，通俗地講，曲軸是一根包含若干曲柄的軸。在直列式發(fā)動機中，每個氣缸對應(yīng)一個曲柄，但是在某些V型發(fā)動機中，一對氣缸會共用一個曲柄。飛輪是一個笨重的盤形鑄鐵件，它安裝在曲軸后端。它通可以使活塞輸出的動力脈沖更平滑，從而減少發(fā)動機的振動。它在做功行程吸收能量，在其它行程釋放能量，這樣可以保持發(fā)動機平穩(wěn)地運轉(zhuǎn)。飛輪的邊緣裝有一圈齒圈，在發(fā)動機起動時，起動機上的小齒輪通過齒圈帶動飛輪旋轉(zhuǎn)。對于自動變速器，在發(fā)動機起動時，是用傳動盤和變矩器代替飛輪實現(xiàn)發(fā)動機的起動?；钊蜌飧妆谥g靠活塞環(huán)來密封，活塞環(huán)裝在活塞上的凹槽中。氣環(huán)用來密封氣體，油環(huán)用來阻止多余的機油從活塞上進入燃燒室。連桿上有一個可以拆掉的連桿蓋，其下端通過一個剖分的連桿軸承與曲軸連接。連桿上端通過與活塞銷組成轉(zhuǎn)動副而與活塞相連。因為可以轉(zhuǎn)動，所以有時候也稱活塞銷為肘節(jié)銷。氣缸蓋通常是鋁合金鑄件，通過螺栓將它固定在缸體頂部并且與氣缸相吻合。在氣缸的上部是燃燒空氣與燃料混合物的燃燒室。氣缸蓋也可以是鑄鐵，這樣具有更強的抗腐蝕性，但是由于鋁合金有較好的熱傳導(dǎo)性和較輕的重量，因而用于汽油機上。氣缸蓋上有進氣孔和排氣孔。在進氣行程，進氣門打開，燃料從進氣孔進入氣缸。在排氣行程，排氣門打開，燃燒后的廢氣從排氣孔排出。凸輪軸和配氣機構(gòu)使氣門在正確的時刻打開和關(guān)閉。凸輪軸由來自曲軸的動力驅(qū)動，其轉(zhuǎn)速是曲軸的一半。氣缸蓋罩裝在氣缸蓋的上面，將配氣機構(gòu)封在里面，并且為發(fā)動機頂部的點火線圈提供額外的保護。四氣缸發(fā)動機的氣缸蓋包含兩根凸輪軸和十六個氣門。在另一種四氣門發(fā)動機上，含有兩根凸輪軸和十二個氣門。還有一種發(fā)動機只有一根凸輪軸和八個氣門。皮帶輪通過正時皮帶以一半的曲軸轉(zhuǎn)速(曲軸轉(zhuǎn)速即發(fā)動機轉(zhuǎn)速)驅(qū)動凸輪軸。常常將有齒輪的皮帶用在這里，但是齒輪和鏈條也會用于某些發(fā)動機，甚至同時使用皮帶和鏈條。在某些發(fā)動機上，會用正時鏈條來驅(qū)動油泵。在柴油機中，噴油泵和凸輪軸都是用正時鏈條或正時齒輪來驅(qū)動。油底殼或者機油箱用來盛放發(fā)動機潤滑系統(tǒng)的機油。油底殼用薄鋼板壓制成型，有些油底殼用鋁合金精密鑄造成型。油底殼用螺栓固定在發(fā)動機下面以便使曲軸箱密封，我們只能看到延伸全曲軸箱外面的曲軸末端。用螺栓連接的零件貼合表面常常要用到各種各樣的墊圈或密封條。有些地方是為了防止泄漏機油，有些地方是為了防止泄漏冷卻液，還有些地方是為了絕熱和保持壓力。有些密封條用于平整表面，還有些用于轉(zhuǎn)軸上。發(fā)動機除了這些大部件，還有許許多多小零件。包括螺栓、墊圈、止動墊圈、彈簧，還有組成發(fā)動機部件的支架。3.發(fā)動機的組成系統(tǒng)以下是發(fā)動機起動和保持運轉(zhuǎn)需要的系統(tǒng):起動系統(tǒng)；燃油系統(tǒng)；點火系統(tǒng)；冷卻系統(tǒng)；潤滑系統(tǒng)；進氣系統(tǒng)；排氣系統(tǒng)；供電系統(tǒng)；電控系統(tǒng)。這是汽油機的組成系統(tǒng)。除了燃油系統(tǒng)和點火系統(tǒng)，柴油機與汽油機具有相似的系統(tǒng)。這些系統(tǒng)中，有些部件是和發(fā)動機一體的，有些是附加上去的，還有些是安裝在發(fā)動機艙里的。啟動系統(tǒng)在發(fā)動機起動時需要用起動機帶動。起動機由電動機和驅(qū)動器組成。在起動時，驅(qū)動器上的小齒輪與飛輪上的齒圈相嚙合。蓄電池給起動機供電帶動發(fā)動機轉(zhuǎn)動，當發(fā)動機著火并自行運轉(zhuǎn)時就算起動成功。燃油系統(tǒng)燃油系統(tǒng)有四種類型：汽油機的化