MarineEngineeringEnglish《輪機英語》APracticalCourseforEngineersWorkingonBoardShips

Lesson4

DieselEngineConstruction∥

柴油機結構

∥2LearningObjectives:1.Graspsomeusefulwordsandexpressionsinthewholetext.2.Afterstudyingthelesson,heorshewillhaveabetterunderstandingofDieselEngineonstruction3

4part1

NewWordsandExpressions5Lesson4DieselEngineConstructionIINewWordsandExpressionsswingv.搖擺deceleratev.減速gripv.緊握，抓牢wedgen.楔塊guttern.槽，溝boostv.提高，增加liablea.易于……的erodev.侵蝕，腐蝕chromiumn.鉻molybdenumn.鉬annulara.環(huán)形的superiora.上等的，優(yōu)良的diametricallyad.徑向的mirrorfinish鏡面度chrome-plated鍍鉻的hydrodynamiclubrication液體動力潤滑6part2

TextAnalysis

Themovingpartsmainlyincludecrosshead,piston,crankshaftandconnectingrod.Lesson4

DieselEngineConstructionII十字頭Text7曲軸連桿運動部件主要包括十字頭、活塞、曲軸和連桿。

ThecrossheadThecrossheadpinconnectsthepistonrodtotheconnectingrod(Fig.4-1).Oneithersideofthecrossheadpinaremountedthecrossheadslippers.Lesson4

DieselEngineConstructionII十字頭銷Text8活塞桿滑塊十字頭銷連接活塞桿和連桿，在十字頭銷的任一側都安裝有十字頭滑塊。

Theslippersrunupanddowninthecrossheadguidesasthepistonandrodarereciprocatingandpreventthetopoftheconnectingrodfrommovingsideways.Lesson4

DieselEngineConstructionIIText9導板往復運動滑塊在十字頭導板上往復運動，就像活塞那樣。Thecrossheadbearing（軸承）isdifficulttolubricateeffectively.

Lesson4

DieselEngineConstructionIIText10有效潤滑十字頭軸承很難實現有效潤滑。

Becausethetopoftheconnectingrodswingsaboutthecrossheadpinandchangesdirectioneachtimethepistonreachesmidstroke,therelativespeedbetweenbearingandpinatmidstrokeiszero,acceleratestoamaximumasthepistonapproachestoporbottomdeadcenterandthendeceleratesbacktozeroagainasthepistonapproachesmidstrokeandtheconnectingrodchangesdirection.①Lesson4

DieselEngineConstructionII擺動Text11相對速度加速本句中Because引出狀語從句，主句中iszero，accelerates及decelerates為并列謂語。全句譯為：因為連桿的頂部繞十字頭銷擺動，并且每當活塞到達沖程中間時改變方向，因此軸承和十字頭銷之間的相對速度在沖程的中間位置時為零，當活塞到達上止點或下止點時加速到最大值，當活塞到達沖程中間時再次減速到零，而連桿改變了運動方向。12

Theloadonthepinisalwaysdownwards,soitisthebottomhalfofthebearingwhichissubjecttowear.Becauseofthehighloadsthebearingmaterialisatin-aluminumalloybondedtoasteelshell.Thepinishighlypolishedtoamirrorfinish.Lesson4

DieselEngineConstructionII下半軸瓦Text13磨損合金十字頭的負載總是向下的，所以下半軸瓦承受磨損，因為負荷很大，使用錫-鋁合金貼合到鋼制的軸瓦上，銷子被鏡面拋光。

Toaccommodatethehighdownwardloadandtoaideffectivelubricationthepinhasalargediameter.Thisincreasestherelativespeedbetweenpinandbearing.Lesson4

DieselEngineConstructionIIText14大的直徑為了容納高的向下的力，并且?guī)椭行У臐櫥?，十字頭銷直徑很大，這個增加了軸承和銷子之間的相對速度。15

Thebottomhalvesofthebearingshellshaveoilgutterscutinthemtoassistthedistributionofoil.Oilissuppliedtothecrossheadusingaswingingarmoratelescopicpipeandissometimesboostedinpressuretoaidefficientlubrication.Lesson4

DieselEngineConstructionII油槽Text16搖臂伸縮管增壓

Theslippersfloatonthejournals,toallowforanyslightmisalignmentintheguides.Therubbingsurfacesarewhitemetallined.Lesson4

DieselEngineConstructionII浮動Text17軸頸失中滑塊是浮動的，允許輕微失中，摩擦表面白合金澆注。

TheguidesurfacesareeithermachinedintotheA-framesorareseparatelycastandmachined,thenboltedtotheAframes.Lesson4

DieselEngineConstructionII車削，加工Text18機架鑄造十字頭導板，有的是加工在A-機架上，有的是單獨鑄造

Thealignmentoftheguidesisveryimportantasistheclearancebetweentheguidesandslippers.Ifthisalignmentisoutoftrueortheclearancesexcessivethenexcessivewearwilloccurbetweenpistonrodandstuffingboxandpistonandcylinderliner.Lesson4

DieselEngineConstructionII對中Text19間隙填料箱氣缸套

ThepistonThepiston(Fig.4-2)comprisesoftwopieces:thecrownandtheskirt.Lesson4

DieselEngineConstructionIIText20組成活塞頭活塞由兩部分組成

Thecrownissubjectedtothehightemperaturesinthecombustionspaceandthesurfaceisliabletobeerodedandburntaway.Lesson4

DieselEngineConstructionII遭受Text21燃燒室燒蝕活塞頭要遭受高溫燒蝕。。。

Forthisreasonthematerialfromwhichthecrownismademustbeabletomaintainitsstrengthandresist

corrosionathightemperatures.Lesson4

DieselEngineConstructionII材料Text22抵抗腐蝕因為這個原因，活塞頭的材料必須能夠保持強度，并能夠抗腐蝕抗高溫。

Thecrownalsocarriesthe4or5

pistonringgrooveswhichmaybe

chrome-plated.Thecastironskirtactsasaguidewithinthecylinderliner.Lesson4

DieselEngineConstructionII活塞環(huán)槽Text23鍍鉻鑄鐵活塞裙活塞頭上有活塞環(huán)槽。。。24

Itisonlyashortskirtonengineswithanexhaustvalve(knownasuniflowscavengedengines),asunlikeatrunkpistonengine,nosidethrustistransmittedtotheliner(that'sthejobofthecrossheadguides).②Lesson4

DieselEngineConstructionII排氣閥Text25掃氣筒形活塞本句中asunlikeatrunkpistonengine,nosidethrustistransmittedtotheliner為原因狀語從句。全句譯為：對于裝有排氣閥的發(fā)動機（所謂的直流掃氣的發(fā)動機），活塞裙是短裙，因為與筒狀活塞的發(fā)動機不同，它沒有側推力傳遞到缸套（該項工作由十字頭導板來承擔）。

Aforgedsteelpistonrodisboltedtotheundersideofthepiston.Theotherendofthepistonrodisattachedtothecrossheadpin.Lesson4

DieselEngineConstructionII鍛造的鋼Text26螺栓活塞27

Pistonsarecooledeitherusingwaterorthecrankcaseoil.Waterhasabettercoolingeffectthanoil,butthereisariskofleakageofwaterintothecrankcase.Modernengineshaveoil-cooledpistons.Lesson4

DieselEngineConstructionII曲柄箱油Text28泄漏活塞可以油冷，也可以水冷，水冷效果好，但是泄漏是問題；當代柴油機大多是油冷活塞。

Thepistonrodisutilizedtocarrytheoiltoandfromthepiston.Therodishollow,andhasatuberunningupitscenter.Thisgivesanannularspacewhich,withthecentralbore,allowsasupplyandreturn.Lesson4

DieselEngineConstructionII中空的Text29管子環(huán)形的活塞桿被用來輸送冷卻油到活塞，并將冷卻油從活塞返回，活塞桿是中空的，里面再插根管子。。。

Analternativemethodofcoolingusesanozzleplateandnozzles.Lesson4

DieselEngineConstructionII其他的Text30噴嘴其他的，可供選擇的，交互變化的

Notethattheoilgoesuptheannularspaceformedbetweentheoiltubeandtheboreinthepistonrod,andreturnsdownthecenter.Theoilissprayedupmatchingboresontotheundersideofthecrown.Lesson4

DieselEngineConstructionII形成，構成Text31噴霧、噴射匹配注意，油是從環(huán)形空間向上，從中間的管子向下的。。32

ThecrankshaftThecrankshaft(fig.4-3)onthelargemodern2-strokecrossheadenginescanweighover300tons.Lesson4

DieselEngineConstructionIIText33曲軸曲軸很重。。。

Theyaretoobigtomakeasasingleunitandsoareconstructedbyjoiningtogetherindividualforgings.Lesson4

DieselEngineConstructionIIText34單獨的鍛件

Onolderenginestheso-calledfullybuiltmethodwasused.Thisconsistedofforgingseparatewebs,crankpinsandmainjournals.

Lesson4

DieselEngineConstructionII全組合式Text35曲柄臂主軸頸老式發(fā)動機上的曲軸多是全組合式的。。。

Thecrankpinsandjournalsweremachinedandmatchingholesboredinthewebs,whichwereslightlysmallerindiameter.Thewebswereheatedupandthecrankpinsandjournalsfittedintotheholes(whichduetotheheathadexpandedinsize).Lesson4

DieselEngineConstructionIIText36稍微小一些曲軸和軸頸的配合方法：紅套法37

Asthewebscooleddown,sothediameteroftheboredholeswouldtryandshrinkbacktotheiroriginalsize.Indoingso,thecrankpinsandjournalswouldbegrippedtightlyenoughtostopthembeingabletoslipwhentheenginewasbeingoperatednormally.Lesson4

DieselEngineConstructionII直徑Text38收縮原來的尺寸當曲柄臂冷卻下來，孔的直徑會收縮到原來的大小，這樣做，曲柄銷和曲柄臂會被牢牢抓緊。。。

Today,crankshaftsforlarge2-strokecrossheadenginesareofthesemibuilttype.Inthismethodofconstructionthecrankshaft"throws”consistingoftwowebsandthecrankpinaremadefromasingleforgingof0.4%carbonsteel.Lesson4

DieselEngineConstructionII半組合式Text39曲拐碳鋼今天，大型二沖程柴油機的曲軸多是半組合式的，這種方法，由兩個曲柄臂和一個曲柄銷組成一個“曲拐”。。。

TheconnectingrodTheconnectingrod(Fig.4-4)isfittedbetweenthecrossheadandthecrankshaft.Lesson4

DieselEngineConstructionII連桿Text40十字頭連桿

Ittransmitsthefiringforce,andtogetherwiththecrankshaftconvertsthereciprocatingmotiontoarotarymotion.Lesson4

DieselEngineConstructionII轉換Text41往復回轉連桿的作用。。。

Connectingrodsonthelaterenginesareproducedasasingledropforgingincorporatingthetophalfofthecrankpinbearinghousingandthebottomhalfofthesolidcrossheadpinbearinghousing.Lesson4

DieselEngineConstructionII一體式鍛件Text42新式發(fā)動機的連桿。。

Onolderenginesthebearingswerewhitemetalthickwallbearings,scrapedtofit.Clearanceswereadjustedbyinsertingorremovingshimsbetweenthebearinghalves.Lesson4

DieselEngineConstructionII厚壁軸承Text43調整墊片老式發(fā)動機上的厚壁軸承，其間隙可以通過插入墊片來調整。

Modernbearingsareofthe“thin-wall”type,whereathinlayerofwhitemetaloratinaluminumalloyisbondedtoasteelshellbacking.Lesson4

DieselEngineConstructionII薄壁軸瓦Text44鍍層合金新式軸承是薄壁軸承，上面有白合金或者錫鋁合金的鍍層。。。45part3

Exercise&Examination1.Duringthepowerstrokeofafour-stroke/cycledieselengine,mostofthesidethrustofatrunk-typepistonisabsorbedbythe_____. A.pistonskirt B.pinion C.crosshead D.compressionrings做工沖程Exercise46筒形活塞在四沖程柴油機的做功沖程中,筒形活塞的側推力大部分被活塞裙吸收了。Lesson4

DieselEngineConstructionIIA____pistonshavelowinertiaandhighcoefficientofthermalexpansion. A.Castiron B.Caststeel C.Forgedsteel D.Aluminum熱膨脹Exercise47鋁質活塞具有慣性小(重量輕)、熱膨脹系數大的特點。。Lesson4

DieselEngineConstructionIIDWhyistheringbeltnarrowerindiameterthantheskirtofapistondesignedforadieselengine?A.Toallowforgreaterexpansionduetohigheroperatingtemperature.B.Tosealthecylinderagainstleakageofcombustiongases.C.ToprovideanadditionalsurfaceforoilcoolingD.Toprovideanadditionalstrengthforthecrownandlowerstructure直徑Exercise48活塞環(huán)區(qū)域的直徑要小于活塞裙處的直徑是為了允許因更高的溫度而導致的更大的膨脹。Lesson4

DieselEngineConstructionIIATheoutsidediameterofthepipeis_____thediameteroftheboreofthepistonrod,theresultbeingthatanannularspaceformedbetweenthepistonrodandthepipe. A.lessthan B.greaterthan C.equalto D.twicelargerthan環(huán)形空間Exercise49管子的外徑比活塞桿內孔的直徑小,結果在活塞桿和管子間形成了環(huán)形空間。Lesson4

DieselEngineConstructionIIAThesealingringsareinfourpartsandpressedtogetheraroundthepistonrodsbymeansof_____.A.nutsB.boltsC.coilspringsD.stuffingboxes密封環(huán)Exercise50密封環(huán)有四部分組成,通過圈彈簧沿活塞桿壓緊。Lesson4

DieselEngineConstructionIICThepistonrodstuffingboxincorporatedinatwo-stroke/cycle,crossheaddieselengineservesto_____.A.eliminatethenecessityforanoilscraperringB.preventsidethrustandcylinderscoringC.preventsludgeanddirtyoilfromenteringthecrankcaseD.scrapeoilandcarbondepositsoffthecylinderwalls活塞桿填料箱Exercise51二沖程十字頭柴油機中使用的活塞桿填料箱,用來防止污物和臟油進入到曲柄箱。Lesson4

DieselEngineConstructionIICOilissuppliedtothecrossheadusingaswingingarmora_____andissometimesboostedinpressuretoandefficientlubrication. A.telescopicpipe B.largeborepipe C.generatingpipe D.centralpipe增壓Exer