轮机英语58课件

MarineEngineeringEnglish《轮机英语》APracticalCourseforEngineersWorkingonBoardShips

Lesson4

DieselEngineConstructionǁ

柴油机结构

ǁ2LearningObjectives:1.Graspsomeusefulwordsandexpressionsinthewholetext.2.Afterstudyingthelesson,heorshewillhaveabetterunderstandingofDieselEngineonstruction3

4part1

NewWordsandExpressions5Lesson4DieselEngineConstructionIINewWordsandExpressionsswingv.摇摆deceleratev.减速gripv.紧握，抓牢wedgen.楔块guttern.槽，沟boostv.提高，增加liablea.易于……的erodev.侵蚀，腐蚀chromiumn.铬molybdenumn.钼annulara.环形的superiora.上等的，优良的diametricallyad.径向的mirrorfinish镜面度chrome-plated镀铬的hydrodynamiclubrication液体动力润滑6part2

TextAnalysis

Themovingpartsmainlyincludecrosshead,piston,crankshaftandconnectingrod.Lesson4

DieselEngineConstructionII十字头Text7曲轴连杆运动部件主要包括十字头、活塞、曲轴和连杆。

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

DieselEngineConstructionII十字头销Text8活塞杆滑块十字头销连接活塞杆和连杆，在十字头销的任一侧都安装有十字头滑块。

Theslippersrunupanddowninthecrossheadguidesasthepistonandrodarereciprocatingandpreventthetopoftheconnectingrodfrommovingsideways.Lesson4

DieselEngineConstructionIIText9导板往复运动滑块在十字头导板上往复运动，就像活塞那样。Thecrossheadbearing（轴承）isdifficulttolubricateeffectively.

Lesson4

DieselEngineConstructionIIText10有效润滑十字头轴承很难实现有效润滑。

Becausethetopoftheconnectingrodswingsaboutthecrossheadpinandchangesdirectioneachtimethepistonreachesmidstroke,therelativespeedbetweenbearingandpinatmidstrokeiszero,acceleratestoamaximumasthepistonapproachestoporbottomdeadcenterandthendeceleratesbacktozeroagainasthepistonapproachesmidstrokeandtheconnectingrodchangesdirection.①Lesson4

DieselEngineConstructionII摆动Text11相对速度加速本句中Because引出状语从句，主句中iszero，accelerates及decelerates为并列谓语。全句译为：因为连杆的顶部绕十字头销摆动，并且每当活塞到达冲程中间时改变方向，因此轴承和十字头销之间的相对速度在冲程的中间位置时为零，当活塞到达上止点或下止点时加速到最大值，当活塞到达冲程中间时再次减速到零，而连杆改变了运动方向。12

Theloadonthepinisalwaysdownwards,soitisthebottomhalfofthebearingwhichissubjecttowear.Becauseofthehighloadsthebearingmaterialisatin-aluminumalloybondedtoasteelshell.Thepinishighlypolishedtoamirrorfinish.Lesson4

DieselEngineConstructionII下半轴瓦Text13磨损合金十字头的负载总是向下的，所以下半轴瓦承受磨损，因为负荷很大，使用锡-铝合金贴合到钢制的轴瓦上，销子被镜面抛光。

Toaccommodatethehighdownwardloadandtoaideffectivelubricationthepinhasalargediameter.Thisincreasestherelativespeedbetweenpinandbearing.Lesson4

DieselEngineConstructionIIText14大的直径为了容纳高的向下的力，并且帮助有效的润滑，十字头销直径很大，这个增加了轴承和销子之间的相对速度。15

Thebottomhalvesofthebearingshellshaveoilgutterscutinthemtoassistthedistributionofoil.Oilissuppliedtothecrossheadusingaswingingarmoratelescopicpipeandissometimesboostedinpressuretoaidefficientlubrication.Lesson4

DieselEngineConstructionII油槽Text16摇臂伸缩管增压

Theslippersfloatonthejournals,toallowforanyslightmisalignmentintheguides.Therubbingsurfacesarewhitemetallined.Lesson4

DieselEngineConstructionII浮动Text17轴颈失中滑块是浮动的，允许轻微失中，摩擦表面白合金浇注。

TheguidesurfacesareeithermachinedintotheA-framesorareseparatelycastandmachined,thenboltedtotheAframes.Lesson4

DieselEngineConstructionII车削，加工Text18机架铸造十字头导板，有的是加工在A-机架上，有的是单独铸造

Thealignmentoftheguidesisveryimportantasistheclearancebetweentheguidesandslippers.Ifthisalignmentisoutoftrueortheclearancesexcessivethenexcessivewearwilloccurbetweenpistonrodandstuffingboxandpistonandcylinderliner.Lesson4

DieselEngineConstructionII对中Text19间隙填料箱气缸套

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

DieselEngineConstructionIIText20组成活塞头活塞由两部分组成

Thecrownissubjectedtothehightemperaturesinthecombustionspaceandthesurfaceisliabletobeerodedandburntaway.Lesson4

DieselEngineConstructionII遭受Text21燃烧室烧蚀活塞头要遭受高温烧蚀。。。

Forthisreasonthematerialfromwhichthecrownismademustbeabletomaintainitsstrengthandresist

corrosionathightemperatures.Lesson4

DieselEngineConstructionII材料Text22抵抗腐蚀因为这个原因，活塞头的材料必须能够保持强度，并能够抗腐蚀抗高温。

Thecrownalsocarriesthe4or5

pistonringgrooveswhichmaybe

chrome-plated.Thecastironskirtactsasaguidewithinthecylinderliner.Lesson4

DieselEngineConstructionII活塞环槽Text23镀铬铸铁活塞裙活塞头上有活塞环槽。。。24

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

DieselEngineConstructionII排气阀Text25扫气筒形活塞本句中asunlikeatrunkpistonengine,nosidethrustistransmittedtotheliner为原因状语从句。全句译为：对于装有排气阀的发动机（所谓的直流扫气的发动机），活塞裙是短裙，因为与筒状活塞的发动机不同，它没有侧推力传递到缸套（该项工作由十字头导板来承担）。

Aforgedsteelpistonrodisboltedtotheundersideofthepiston.Theotherendofthepistonrodisattachedtothecrossheadpin.Lesson4

DieselEngineConstructionII锻造的钢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，但是泄漏是问题；当代柴油机大多是油冷活塞。

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

DieselEngineConstructionII中空的Text29管子环形的活塞杆被用来输送冷却油到活塞，并将冷却油从活塞返回，活塞杆是中空的，里面再插根管子。。。

Analternativemethodofcoolingusesanozzleplateandnozzles.Lesson4

DieselEngineConstructionII其他的Text30喷嘴其他的，可供选择的，交互变化的

Notethattheoilgoesuptheannularspaceformedbetweentheoiltubeandtheboreinthepistonrod,andreturnsdownthecenter.Theoilissprayedupmatchingboresontotheundersideofthecrown.Lesson4

DieselEngineConstructionII形成，构成Text31喷雾、喷射匹配注意，油是从环形空间向上，从中间的管子向下的。。32

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

DieselEngineConstructionIIText33曲轴曲轴很重。。。

Theyaretoobigtomakeasasingleunitandsoareconstructedbyjoiningtogetherindividualforgings.Lesson4

DieselEngineConstructionIIText34单独的锻件

Onolderenginestheso-calledfullybuiltmethodwasused.Thisconsistedofforgingseparatewebs,crankpinsandmainjournals.

Lesson4

DieselEngineConstructionII全组合式Text35曲柄臂主轴颈老式发动机上的曲轴多是全组合式的。。。

Thecrankpinsandjournalsweremachinedandmatchingholesboredinthewebs,whichwereslightlysmallerindiameter.Thewebswereheatedupandthecrankpinsandjournalsfittedintotheholes(whichduetotheheathadexpandedinsize).Lesson4

DieselEngineConstructionIIText36稍微小一些曲轴和轴颈的配合方法：红套法37

Asthewebscooleddown,sothediameteroftheboredholeswouldtryandshrinkbacktotheiroriginalsize.Indoingso,thecrankpinsandjournalswouldbegrippedtightlyenoughtostopthembeingabletoslipwhentheenginewasbeingoperatednormally.Lesson4

DieselEngineConstructionII直径Text38收缩原来的尺寸当曲柄臂冷却下来，孔的直径会收缩到原来的大小，这样做，曲柄销和曲柄臂会被牢牢抓紧。。。

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

DieselEngineConstructionII半组合式Text39曲拐碳钢今天，大型二冲程柴油机的曲轴多是半组合式的，这种方法，由两个曲柄臂和一个曲柄销组成一个“曲拐”。。。

TheconnectingrodTheconnectingrod(Fig.4-4)isfittedbetweenthecrossheadandthecrankshaft.Lesson4

DieselEngineConstructionII连杆Text40十字头连杆

Ittransmitsthefiringforce,andtogetherwiththecrankshaftconvertsthereciprocatingmotiontoarotarymotion.Lesson4

DieselEngineConstructionII转换Text41往复回转连杆的作用。。。

Connectingrodsonthelaterenginesareproducedasasingledropforgingincorporatingthetophalfofthecrankpinbearinghousingandthebottomhalfofthesolidcrossheadpinbearinghousing.Lesson4

DieselEngineConstructionII一体式锻件Text42新式发动机的连杆。。

Onolderenginesthebearingswerewhitemetalthickwallbearings,scrapedtofit.Clearanceswereadjustedbyinsertingorremovingshimsbetweenthebearinghalves.Lesson4

DieselEngineConstructionII厚壁轴承Text43调整垫片老式发动机上的厚壁轴承，其间隙可以通过插入垫片来调整。

Modernbearingsareofthe“thin-wall”type,whereathinlayerofwhitemetaloratinaluminumalloyisbondedtoasteelshellbacking.Lesson4

DieselEngineConstructionII薄壁轴瓦Text44镀层合金新式轴承是薄壁轴承，上面有白合金或者锡铝合金的镀层。。。45part3

Exercise&Examination1.Duringthepowerstrokeofafour-stroke/cycledieselengine,mostofthesidethrustofatrunk-typepistonisabsorbedbythe_____. A.pistonskirt B.pinion C.crosshead D.compressionrings做工冲程Exercise46筒形活塞在四冲程柴油机的做功冲程中,筒形活塞的侧推力大部分被活塞裙吸收了。Lesson4

DieselEngineConstructionIIA____pistonshavelowinertiaandhighcoefficientofthermalexpansion. A.Castiron B.Caststeel C.Forgedsteel D.Aluminum热膨胀Exercise47铝质活塞具有惯性小(重量轻)、热膨胀系数大的特点。。Lesson4

DieselEngineConstructionIIDWhyistheringbeltnarrowerindiameterthantheskirtofapistondesignedforadieselengine?A.Toallowforgreaterexpansionduetohigheroperatingtemperature.B.Tosealthecylinderagainstleakageofcombustiongases.C.ToprovideanadditionalsurfaceforoilcoolingD.Toprovideanadditionalstrengthforthecrownandlowerstructure直径Exercise48活塞环区域的直径要小于活塞裙处的直径是为了允许因更高的温度而导致的更大的膨胀。Lesson4

DieselEngineConstructionIIATheoutsidediameterofthepipeis_____thediameteroftheboreofthepistonrod,theresultbeingthatanannularspaceformedbetweenthepistonrodandthepipe. A.lessthan B.greaterthan C.equalto D.twicelargerthan环形空间Exercise49管子的外径比活塞杆内孔的直径小,结果在活塞杆和管子间形成了环形空间。Lesson4

DieselEngineConstructionIIAThesealingringsareinfourpartsandpressedtogetheraroundthepistonrodsbymeansof_____.A.nutsB.boltsC.coilspringsD.stuffingboxes密封环Exercise50密封环有四部分组成,通过圈弹簧沿活塞杆压紧。Lesson4

DieselEngineConstructionIICThepistonrodstuffingboxincorporatedinatwo-stroke/cycle,crossheaddieselengineservesto_____.A.eliminatethenecessityforanoilscraperringB.preventsidethrustandcylinderscoringC.preventsludgeanddirtyoilfromenteringthecrankcaseD.scrapeoilandcarbondepositsoffthecylinderwalls活塞杆填料箱Exercise51二冲程十字头柴油机中使用的活塞杆填料箱,用来防止污物和脏油进入到曲柄箱。Lesson4

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