轮机英语78课件

MarineEngineeringEnglish《轮机英语》APracticalCourseforEngineersWorkingonBoardShips

Lesson3

DieselEngineConstruction

柴油机结构

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

4part1

NewWordsandExpressions5Lesson3DieselEngineConstructionINewWordsandExpressionsfoundationn.基础rigida.坚固的，结实的flexiblea.柔性的，灵活的hogv.使拱起，上拱sagv.使下沉，下陷flexv.弯曲并伸展longitudinala.纵向的individuallyad.独立地erectv.建立，竖立fabricateda.锻造的reamv.铰孔holdingdownbolts底脚螺栓thrustcollar推力环fittedbolt紧配螺栓tie-rod贯穿螺栓bearinghousing轴承座bedplate机座castiron铸铁fabricatedsteel锻钢6part2

TextAnalysis

Thedieselenginemainlyconsistsoftwokindsofparts:thefixedpartsandthemovingparts.Inthepartoneofthisarticle,wemainlytalkaboutthefixedpartsofdieselengine.Lesson3DieselEngineConstructionI包括，包含Text7固定部件运动部件柴油机结构主要包括固定部件和运动部件；这篇课文主要讨论固定部件。

Typicallythefixedpartsincludebedplate,tie-rods,A-frameandcylinderliner,etc.Thereisastructuraldiagramoflargemarinedieselenginebelow.（Fig.3-1）Lesson3DieselEngineConstructionI机座Text8贯穿螺栓机架典型的固定部件包括：气缸套

Lesson3DieselEngineConstructionIText9典型的固定部件包括：

Thebedplate(Fig.3-2a)isthefoundationonwhichthe2-strokeengineisbuilt.Itmustberigidenoughtosupporttheweightoftherestoftheengine,andmaintainthecrankshaft,whichsitsinthebearinghousingsinthetransversegirders,inalignment.Lesson3DieselEngineConstructionI基础Text10足够坚固曲轴机座是发动机的基础。。。轴承座对中

Atthesametimeitmustbeflexibleenoughtohogandsagwiththefoundationplatetowhichitisattachedandwhichformspartoftheship’sstructure.Lesson3DieselEngineConstructionI包括，包含Text11拱腰和塌腰结构机座也必须有一定的柔性（弹性）

Ifthebedplatewastoorigid,thenasthehullflexed,theholdingdownbolts,whichsecuretheengineintotheship,wouldbelikelytobreak,andtherewouldbeadangerofthebedplatecracking.

Lesson3DieselEngineConstructionI螺栓Text12固定裂纹本段了解即可13Fig.3-2BedplateandA-frameTheA-frames(Fig.3-2b)carrythecrossheadguidesandsupporttheengineentablature(thecylinderblock).Onlargeengines,theA-framesareindividuallyerectedonthebedplatedirectlyabovethetransversegirders.

Lesson3DieselEngineConstructionI十字头导板Text14机体气缸体A型机架上有十字头导板，并且支撑机体（气缸体）单独的

Whenboxedinwithplatingtheyformthecrankcase.Thetrendnowadaysistobuildtheframeboxasaseparatefabricatedconstructionandthen,afterstressrelievingandmachiningthematingsurfaces,tomountitonthebedplate.Lesson3DieselEngineConstructionI曲柄箱Text15锻造应力释放本段了解即可车削，加工

Whentheframesarealignedonthebed-platetheyaresecuredtogetherbydrillingandreamingandusingfittedbolt.Lesson3DieselEngineConstructionI对中Text16钻孔Toholdthebed-plate,framesandentablaturefirmlytogetherincompression,andtotransmitthefiringforcesbacktothebedplate,longtiebolts(Fig.3-3)arefittedthroughthesethreecomponentsandthentightenedhydraulically.Lesson3DieselEngineConstructionI压缩，压紧Text17燃烧的力贯穿螺栓贯穿螺栓的作用。。。部件液压的18

Topreventexcessivebendingmomentsinthetransversegirders,thetieboltsarepositionedasclosetothecenterofthecrankshaftaspossible.Lesson3DieselEngineConstructionI弯曲运动Text19横梁曲轴贯穿螺栓应该尽量靠近曲轴（避免横梁弯矩）

Becausethetieboltsaresoclosetothecrankshaft,someenginesemployjackboltstoholdthecrankshaftmainbearingcapinpositioninsteadofconventionalstudsandnuts.Lesson3DieselEngineConstructionI撑杆螺栓Text20轴承盖传统的本段了解，掌握单词即可Thecylinderliner(Fig.3-4)formsthecylindricalspaceinwhichthepistonreciprocates.Thereasonsformanufacturingthelinerseparatelyfromthecylinderblockinwhichitislocatedareasfollows.②Lesson3DieselEngineConstructionI往复Text21制造位置，放置活塞在气缸内往复运动气缸套和气缸体要分开制造

1.Thelinercanbemanufacturedusingasuperiormaterialtothecylinderblock.Whilethecylinderblockismadefromagraycastiron,thelinerismanufacturedfromacastironalloyedwithchromium,vanadiumandmolybdenum.Lesson3DieselEngineConstructionIbetterText22灰铸铁合金铸铁缸套的材料，是铸铁合金。。。23

Thelinerwillgettendtogetveryhotduringengineoperationastheheatenergyfromtheburningfuelistransferredtothecylinderwall.Sothatthetemperaturecanbekeptwithinacceptablelimitsthelineriscooled.Lesson3DieselEngineConstructionIText24极限，限制缸套会因为燃油的燃烧变得越来越热，所以要冷却

Cylinderlinersfromolderlowerpoweredengineshadauniformwallthicknessandthecoolingwasachievedbycirculatingcoolingwaterthroughaspaceformedbetweenlinerandjacket.Lesson3DieselEngineConstructionI均匀的，一致的Text25厚度气缸的内套和外套以往的气缸壁，厚度是一致的

Thecoolingwaterspacewassealedfromthescavengespaceusing"O”ringsandatelltalepassagebetweenthe"O”ringsledtotheoutsideofthecylinderblocktoshowaleakage.Lesson3DieselEngineConstructionI扫气箱Text26O型密封圈泄漏气缸套的下侧密封。。。

Toincreasethepoweroftheengineforagivennumberofcylinders,eithertheefficiencyoftheenginemustbeincreasedormorefuelmustbeburntpercycle.Lesson3DieselEngineConstructionIText27效率为了增加发动机功率，要么增加效率，要么增加喷油量

Tobummorefuel,thevolumeofthecombustionspacemustbeincreased,andthemassofairforcombustionmustbeincreased.Lesson3DieselEngineConstructionI容积Text28燃烧室为了燃烧更多的燃油，燃烧室的容积必须增加并且。。

Becauseoftheresultinghigherpressuresinthecylinderfromthecombustionofthisgreatermassoffuel,andthelargerdiameters,thelinermustbemadethickeratthetoptoaccommodatethehigherstresses,andpreventcrackingofthematerial.Lesson3DieselEngineConstructionI直径Text29更厚材料的裂纹把气缸套上部，也就是构成燃烧室的部分做的更厚，（然后钻孔冷却）30part3

Exercise&Examination1.Anumberofcylinderlinersareenclosedinonecastironcasingtoforma_____. A.cylindercover B.cylinderblock C.cylinderframe D.bed-plate 气缸套Exercise31气缸体几个缸套被封闭在一个铸铁件内便形成了一个气缸体。。Lesson3DieselEngineConstructionIB2.Thereisasupportringbetweenthecylinderblockandthecollarofthecylinderliner,thuscarryingboththelinerandthecylindercover.Italsopasses_____tothecoolingboresandtothecover. A.coolingwater B.coolingoil C.refrigerant D.lubricateoil卡环（衣服的领子）Exercise32气缸盖缸体和缸套凸缘间有支撑环,用来支撑缸套和缸盖。同时,它将冷却水通到冷却腔和气缸盖。Lesson3DieselEngineConstructionIA3.Inordertoincreasethewearingresistance,thecylinderlinersurfacesaresometimes_____. A.aluminum-plated B.bronze-plated C.zinc-plated D.chromium-plated抗磨损Exercise33为了提高抗磨性能,缸套表面经常镀铬。。Lesson3DieselEngineConstructionID4.A_____isthefoundationoftheengine,withoutthesupportofwhichtheshaftalignmentinparticular,andenginestructureasawhole,wouldinevitablybelost. A.Frame B.Bedplate C.Cylinder D.Liner做工冲程Exercise34盘车机机座是发动机的基础,如无其支撑,发动机整体结构,尤其是轴的对中都将无从保证。 。Lesson3DieselEngineConstructionIB5.Onemethodofconstructinglargemarinedieselenginesandreducingthetotalengineframeweightisthrough_____. A.castinginterlockingcomponents B.weldingplatestoformsectionsforassembly C.forgingintegralcomponents D.casehardeningintegralcomponents机架Exercise35建造大型船用柴油机时,为减少整台发动机机架的重量,可采用焊接钢板形成分段部件来组装。Lesson3DieselEngineConstructionIB6.AtthetopoftheA-framesthereisastrongcastironframecalled_____. A.cylinderliner B.cylindercover C.thegearbox D.thescavengingbox铸铁Exercise36A型机架的顶部有一个铸铁架,即扫气箱。Lesson3DieselEngineConstructionID7.A-framesandcylinderblockisheldtogetherby_____toformarigidstructure.

A.connectingrods B.pistonrods C.tierods D.jack-bolts结构Exercise37A型机架和气缸体用贯穿螺栓固定。。Lesson3DieselEngineConstructionIC8.Eachcylinderisclosedatthetopbya_____,madeofaspecialheat-resistantsteel. A.cylinderliner B.couplingflange C.cylindercover D.pistoncrown耐热钢Exercise38气缸的顶部由气缸盖封闭,缸盖由特殊的耐热钢制造。 Lesson3DieselEngineConstructionID9.Topreventexcessive_____inthetransversegirders,thetieboltsarepositionedasclosetothecenterofthecrankshaftaspossible. A.thermalstresses B.bendingmoments C.thermalloads D.surfacetensionsExercise39为避免横梁受到过大的弯矩,贯穿螺栓的位置应尽可能靠近曲轴的中心。Lesson3DieselEngineConstructionIB10.Atleast_____cylindersinfour-strokeenginewillbeconfiguredtoensurethattheenginecanbestartedwiththecrankshaftatwhateverposition. A.6 B.2 C.12 D.8Exercise40四冲程柴油机要能正常工作至少需要6个气缸。 Lesson3DieselEngineConstruction