輪機(jī)英語58課件

MarineEngineeringEnglish《輪機(jī)英語》APracticalCourseforEngineersWorkingonBoardShips

Lesson4

DieselEngineConstruction∥

柴油機(jī)結(jié)構(gòu)

∥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(dòng)力潤滑6part2

TextAnalysis

Themovingpartsmainlyincludecrosshead,piston,crankshaftandconnectingrod.Lesson4

DieselEngineConstructionII十字頭Text7曲軸連桿運(yùn)動(dòng)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(cè)都安裝有十字頭滑塊。

Theslippersrunupanddowninthecrossheadguidesasthepistonandrodarereciprocatingandpreventthetopoftheconnectingrodfrommovingsideways.Lesson4

DieselEngineConstructionIIText9導(dǎo)板往復(fù)運(yùn)動(dòng)滑塊在十字頭導(dǎo)板上往復(fù)運(yùn)動(dòng)，就像活塞那樣。Thecrossheadbearing（軸承）isdifficulttolubricateeffectively.

Lesson4

DieselEngineConstructionIIText10有效潤滑十字頭軸承很難實(shí)現(xiàn)有效潤滑。

Becausethetopoftheconnectingrodswingsaboutthecrossheadpinandchangesdirectioneachtimethepistonreachesmidstroke,therelativespeedbetweenbearingandpinatmidstrokeiszero,acceleratestoamaximumasthepistonapproachestoporbottomdeadcenterandthendeceleratesbacktozeroagainasthepistonapproachesmidstrokeandtheconnectingrodchangesdirection.①Lesson4

DieselEngineConstructionII擺動(dòng)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?yàn)檫B桿的頂部繞十字頭銷擺動(dòng)，并且每當(dāng)活塞到達(dá)沖程中間時(shí)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(shí)為零，當(dāng)活塞到達(dá)上止點(diǎn)或下止點(diǎn)時(shí)加速到最大值，當(dāng)活塞到達(dá)沖程中間時(shí)再次減速到零，而連桿改變了運(yùn)動(dòng)方向。12

Theloadonthepinisalwaysdownwards,soitisthebottomhalfofthebearingwhichissubjecttowear.Becauseofthehighloadsthebearingmaterialisatin-aluminumalloybondedtoasteelshell.Thepinishighlypolishedtoamirrorfinish.Lesson4

DieselEngineConstructionII下半軸瓦Text13磨損合金十字頭的負(fù)載總是向下的，所以下半軸瓦承受磨損，因?yàn)樨?fù)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(gè)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(dòng)Text17軸頸失中滑塊是浮動(dòng)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(jī)架鑄造十字頭導(dǎo)板，有的是加工在A-機(jī)架上，有的是單獨(dú)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?zé)g。。。

Forthisreasonthematerialfromwhichthecrownismademustbeabletomaintainitsstrengthandresist

corrosionathightemperatures.Lesson4

DieselEngineConstructionII材料Text22抵抗腐蝕因?yàn)檫@個(gè)原因，活塞頭的材料必須能夠保持強(qiáng)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(dòng)機(jī)（所謂的直流掃氣的發(fā)動(dòng)機(jī)），活塞裙是短裙，因?yàn)榕c筒狀活塞的發(fā)動(dòng)機(jī)不同，它沒有側(cè)推力傳遞到缸套（該項(xiàng)工作由十字頭導(dǎo)板來承擔(dān)）。

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(dāng)代柴油機(jī)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(gòu)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(dú)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(dòng)機(jī)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(dāng)曲柄臂冷卻下來，孔的直徑會(huì)收縮到原來的大小，這樣做，曲柄銷和曲柄臂會(huì)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(jī)的曲軸多是半組合式的，這種方法，由兩個(gè)曲柄臂和一個(gè)曲柄銷組成一個(gè)“曲拐”。。。

TheconnectingrodTheconnectingrod(Fig.4-4)isfittedbetweenthecrossheadandthecrankshaft.Lesson4

DieselEngineConstructionII連桿Text40十字頭連桿

Ittransmitsthefiringforce,andtogetherwiththecrankshaftconvertsthereciprocatingmotiontoarotarymotion.Lesson4

DieselEngineConstructionII轉(zhuǎn)換Text41往復(fù)回轉(zhuǎn)連桿的作用。。。

Connectingrodsonthelaterenginesareproducedasasingledropforgingincorporatingthetophalfofthecrankpinbearinghousingandthebottomhalfofthesolidcrossheadpinbearinghousing.Lesson4

DieselEngineConstructionII一體式鍛件Text42新式發(fā)動(dòng)機(jī)的連桿。。

Onolderenginesthebearingswerewhitemetalthickwallbearings,scrapedtofit.Clearanceswereadjustedbyinsertingorremovingshimsbetweenthebearinghalves.Lesson4

DieselEngineConstructionII厚壁軸承Text43調(diào)整墊片老式發(fā)動(dòng)機(jī)上的厚壁軸承，其間隙可以通過插入墊片來調(diào)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(jī)的做功沖程中,筒形活塞的側(cè)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(zhì)活塞具有慣性小(重量輕)、熱膨脹系數(shù)大的特點(diǎn)。。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(dǎo)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(nèi)孔的直徑小,結(jié)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(jī)中使用的活塞桿填料箱,用來防止污物和臟油進(jìn)入到曲柄箱。Lesson4

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