轮机全部课件英语lesson2

LessonTwo

TextDieselEngineConstruction(I)

Prof.SongZhouNewWordsandExpressionsinTextconstruction结构bedplate机座frame机架weld焊接bolt螺栓；用螺栓固定seating座，底座liner(气缸)衬套extend延长，伸长slot槽，缝；开槽opening开口height高度secure固定transverse横向的chock侧块，楔型块longitudinal纵向的test放置，坐落bearing轴承cross十字的，交叉的；stud双头螺栓cap盖，帽thrust推，推力block块，体locate位于，查出，找出integral整体的flat平的surface表面mount安装section段，表面camshaft凸轮轴enclose包围，封闭casing箱，外壳jacket夹层，水套vertical垂直的flange法兰，翻边foremost最前的expose易露，露出edge边缘drill钻孔rotary旋转的guide导板，导向器，导向，引导insert插入groove槽，沟turn车削，转动conical锥形的screw螺钉；用螺钉固定，拧入indicator示功器cock旋塞double双层的castiron铸铁chaintransmission链条传动(机构)chromium镀铬machine-turned车削的，车制的approx大约heat-resistant耐热的Bedplate(机座)andFrame(机架)Thebedplate,whichinmostcasesis

oftheweldeddesign,is

boltedtotheseating

whichformspartofthedoublebottomoftheship.CylinderblockA-Frame(Entablature)BedplateTierodSeatingCylindercoverItissecured(固定)inthetransverse(横向的)directionbymeansofboltsknownasside-chockbolts(侧楔螺栓)

andinlongitudinal(纵向的)directionbymeansofend-chockbolt(端楔螺栓).Thecrankshaftrests(放置、坐落)inbearing

builtintocrossgirders(横梁)ofthebedplate.BearingCrossgirderHousingThesebearings,knownasmainbearings,eachconsistoftwoshells(轴瓦)whicharesupportedinhousings(轴承座)

machinedinthebedplateandsecuredbymeansofstuds(双头螺栓)andbearingcaps(轴承盖).Thethrustblock

orthrustbearing(推力轴承),locatedattheaftendoftheengine,maybeintegralwith,orseparatefrom,thebedplate.*Onthe

flat(平的)

uppersurfaceofthebedplate

arearranged

anumberofA-shapedframesorentablatures(机架)whichmaybemanufacturedofcastironorfabricatedsteel(结构钢).Theframesaremountedonandboltedtothebedplatecrossgirders.AtthetopoftheA-framesthereisastrongcastironframecalledthescavengingairbox,whichisbuiltofanumberofsectionsprovidedwithverticalflanges(法兰)

enablingthemtobeboltedtogethertoformablockfor1-3cylindersinfrontofthechaintransmission,andablockwith4-6cylindersaftofthechaintransmission.Thechaintransmission,formingtheconnectionbetweenthecrankshaftandthecamshaft,isenclosed

inacastironcasing

knownasthechaindrivecasing.CylindersandCoversOntopofscavengingairboxismountedastrongcastironframeforeachcylinder.Theseframesareknownascylinderblocksorcoolingjackets(冷却水套),whichareprovidedwithvertical

flangesenablingthemtobeboltedtogetherin

the

foremostandaftmostgroupsinthesamewayasthescavengingairboxes.Thebedplate,framesandcylinderblocksaresecuredtogetherbylongtie-rods(轨距杆)toachieveagreaterrigidconstruction(刚性结构)withlessdeformation(变形)

inserviceandlowervibration.Thecylinderliners

aremadeofalloyedcastironandthecylindersurfacesaresometimeschromium-plated(镀铬).Thecylinderlinersareextend

somewhat

downinthescavengingairbox,andsealingbetweenthelinerandthetopofthescavengingairboxisachievedbytherubberringsfittedintotheslotsmachine-turned(机加工的)intheliners.Inthepartofthecylinderlinerinsidethescavengingairboxthereisaseriesofopeningsknownasscavengingairports.Theseportsarelocatedatsuchaheightthattheyarejustexposedbytheupperedgeofthepistonwhenthepistonisinthebottomdead-centerposition.Theportsaredrilledinthelinersatanangleofapprox.20°,theresultbeingthatthescavengingairisgivenarotarymovement.Eachcylinderisclosedatthetopbyacylindercover,madeofaspecialheat-resistantsteel(耐热钢).Thecoverismountedagainstaflatsurfaceatthetopofthecylinderlinerandlocatedonthelinerbymeansofamachine-turnedguideedge.Asealingringisinsertedinagroove

turnedintheconical(园锥形的)partofthecover.Thefittingofthesealingringintheconicalsurfacemustbecarriedoutwithgreatcare.Thecylindercoversandthelinersareboltedtogetherbymeansofstudsscrewedintothecylinderframes.Thecylinderlinerhasdrillingsforcylinderlubrication,and,inlatertypes,hasdrillingsforcoolingwaterattheuppermostpartofit.Ineachcylindercoverisalargecentralopeningformountingtheexhaustvalve,andtwoorthreeholesforthefuelvalves.Thecylindercoverisalsoprovidedwithholesfor:thestartingvalve;thesafetyvalve;theindicatorcock(示功器旋塞);thecooling-waterinletandthecooling-wateroutlettotheexhaustvalvecoolingchamber.NewWordsbedplateStructureformingthebaseofamachine.Inamarineengine,inadditiontosupportingtheenginecolumnsandcrankshaftbearings,italsohelpstodistributetheengineweightandstresstotheship’sstructure.frameTransversestructurememberactingasastiffenertotheshellandbottomplate.Canalsobelongitudinal;knownastheribsofaship.ReadingMaterialSulzerMarineDieselEnginesSulzerRND-MEngineTheRND-MSulzerisasingleactingslowspeed，two-stroke,reversible(可倒转)engine.Theindividualcylinderrunninggearismadeupofapiston，pistonrodandconnectingrodjoiningthesinglethrow(曲柄)ofcrankshaft.Thebedplateisfabricatedasadoublewalldesignwithlongitudinalboxsectiongirders.

A-framesaremountedonthebedplateandsupporttheentablature

andcylinderblock．Thecompleteassemblyofbedplate，A-framesandcylinderblockareheldtogetherbytierodstoformarigidstructure.Toresistcrankshaft-loadingtransversebending(弯曲)themainbearing

keep(主轴承盖)arehelddownbyjack-bolts(液压撑杆螺栓).Thisstrongstructureisnecessarytowithstand

thecombustionloadswhichpassviathecylinderheadtotheenginestructure．keepThecrankshaftissemi-built(半总成式)withthecrankwebs(曲柄臂)beingdesignedtopartiallybalancetherotatingmasses．Thecylindercoverismadeinsinglepiece

andcontains

thecentralfuelinjector，thestartingairvalve，reliefvalve(安全阀)andindicatorcock．Exhaustgasdriventurbo-chargersoperatingontheconstantpressuresystem

supplyscavengeair.Looptypescavengingisemployedandanelectricallydrivenautomaticallyoperatingauxiliaryblowerisprovidedforslowspeedandmaneuveringoperations.Lubricatingoilissuppliedtoalowandamediumpressuresystem.Thelow-pressuresystemsuppliesthemainandotherbearings.Thecrosshead(十字头)bearingsaresuppliedbythemediumpressuresystem.Articulatedpipes(铰链管)supplytheoiltothecrossheadbearings.Water-coolingisusedforcylinderjacketsandheadsandalsothepistons.Telescopicpipes(伸缩管，套管式)providethewatertothepistons.FuelinjectionusestheJerkpump(高压喷射泵)systemandaWoodwardtypehydraulicgovernor(液压调速器)isusedtocontrolenginespeed.TheRLengineisbasedontheRND-Mandprovides,withitsincreasedpistonstroke,ahigheroutputandlowerenginespeed.Newfeaturesincludeasinglewallbedplatewithintegralthrustblock.Alsothepistoncrown(活塞头)andothermaincomponentsofthecombustionchamberare

borecooled(钻孔冷却),i.e.bywatercirculating

inholesboredclosetothehotsurfaces.SulzerRTAEngineTheSulzerRTA84Cisatypicalmodernslow-speed,two-stroke,crossheadtype,longstrokeengine.Ithasaboreof840mm,astrokeof2,400mmandanoperatingspeedof100r/min.Itisavailablewithbetweenfourandtwelvecylindersandisparticularlyproducedforthelarge,fastcontainership(集装箱船)market.ItsdesignandconstructionissimilartootherenginesintheRTAseries2whichofferanumberofcylindersizesdownto380mm.Adeepsinglewall-boxtypebedplatefabricatedfromweldedsteelplatesandcastings,andsubstantial(坚固的)welded‘A’framessurmounted(安在…顶上)bycastironcylinderjacketsboltedtogethertoformacylinderblock,togethergiverigidoverallconstruction.Thestructureispre-stressed(预加应力)bylongverticaltiebolts.Cylinderlinersareofalloycastiron.Astiff(硬的)collarattheupperendresiststheheavygasload;thislandsonthecylinderjacket.Itisborecooledwithwaterflowratesregulatedtomaintaincorrecttemperaturesthroughouttheliner.Thelowerendisuncooledwithinthescavengespace.Multi-levelcylinderlubricationisusedtoreducelinerwearrates.Thesolidforgedsteel(锻钢)cylindercoverisborecooledtoreducethermalstress(热应力)andtoconductheatfromthefuelinjectorpockets(腔).Acentrallypositionedlargeexhaustvalvecage(腔)hasitsvalveseatintensively(强烈的、集中的)cooled,takingwaterfromthecover.ThevalveismanufacturedofNimonic(镍铬钛合金)80Aalloyandisrotatedbyvanes(叶片式旋阀器)

fittedtoitsspindle(阀杆).Itisopenedbyhydraulicpressurefromacamdrivenactuator(驱动器、执行器)andisclosedundertheactionofanairspring.Thepistonhasanalloysteelcrownandhasfivecompressionringsfittedinchromiumplatedgrooves.Thereisashortcastironskirt(裙部).Thepistonisoilcooledusingboththe‘shaker(震荡,摇杆)’methodandsmalljets(射流)topropeloilintoboreholesclosetotheundersideofthecrownandbehindtheringgrooves.Oilforcoolingissuppliedandreturnedthroughaboreinthepistonrodfromswinging(摇摆)linksatthecrosshead.Thesinglepiececrossheadhasthepistonrodboltedtoitsuppersurfaceandacontinuousfull-lengthlowerhalf(全支承式),topendbearing,whichisofwhitemetalandlubricatedwithhighpressureoil.Guideshoes(导块，滑块)areattachedtoeachendofthecrosshead.Asemi-builtupcrankshaft(半套合式,半总成式)hasslim(细的)webstoallowlargebearingareas;mainbearingcapsaresecuredbyjackboltsfromtheengineframes．Themaincamshaftisgeardrivenandisfittedwithservomotors(伺服马达)tore-timefuelpumpcamsandtheairstartdistributor(起动空气分配器)

whenoperatingtheengineastern(向后)．

Fuelpumpsareofthecam-drivenvalve-timedtype，withvariable

ignitiontiming(VIT机构,可变点火定时)toadjusttimingandmaintainefficientcombustionatlowspeed.Eachpumpsuppliedthreeuncooledfuelinjectorsplacedsymmetrically(对称地)ineachcover．Hotfueloilcirculatesthevalveswhennotinjecting．Theenginehasthrough-scavenge(直流扫气)andconstantpressureturbochargingwithahighefficiency，uncooledturbochargersupplementedatverylowspeedsbytwoconstantspeed，electricdrivenauxiliaryairblowers．ENDTherebe/stand(站立)/lie(平放)/appear(出现)/occur(发生)/exist(存在)倒装句：例：Therestandsalargehydroelectricpowerstationontheriver.Jimeiuniversity2.Here/There/Thus/Then/Hence开头的句子中，主语是名词，而谓语用Come,go一类的动词时，整个句子应采用完全倒装语序。例：HerecomesourEnglishteacher.Listen,theregoesthebell.3.“衔接”倒装：有时，为了衔接而将谓语中的分词置于句首，从而引起倒装。这种句子的主语往往带有较长的后置定语，倒装语序使句子显得更加平衡。例：Punchedonthetapesareanumberofholeswhichmeanbinary1’sforthecomputer.4.“强调”倒装：为了强调，将句末的状语提到句首，引起主谓语倒装。Inthisdesignareinvolvedanumberofcomplicatedproblemswhichshouldbesol