机电工程专业英语

CONTENTS,Lesson1IntroductiontoMachineryDesignLesson2MechanismsLesson3MachineParts(I)Lesson4MachineParts(II)Lesson5EngineeringGraphicintheThird-angleProjectionLesson6IntroductiontoCAD/CAM/CAPPLesson7ADiscussiononModernDesignOptimizationLesson8UsingDynamicSimulationintheDevelopmentofConstructionMachineryLesson9EngineeringToleranceLesson10NumericalControl,Lesson11IntroductiontoHeatPipeTechnologyinMachiningProcessLesson12IntroductiontoMaterialFormingLesson13MaterialFormingProcessesLesson14IntroductiontoMouldLesson15MouldDesignandManufacturingLesson16HeatTreatmentofMetalLesson17VirtualManufacturingLesson18FluidandHydraulicSystemLesson19ProductTestandQualityControlLesson20IntroductionofAutomobileEngine,Lesson21TheAutomobileComponentsLesson22MechatronicsLesson23IndustrialRobotsLesson24AnArmyofSmallRobotsLesson25IntroductiontoMEMSLesson26DialogueAtCIMTLesson27VirtualManufacturing,Lesson1IntroductiontoMachineryDesign1.1Text1Machinerydesigniseithertoformulateanengineeringplanforthesatisfactionofaspecifiedneedortosolveanengineeringproblem.Itinvolvesarangeofdisciplinesinmaterials,mechanics,heat,flow,control,electronicsandproduction.,MachineryComponentsThemajorpartofamachineisthemechanicalsystem.3Andthemechanicalsystemisdecomposedintomechanisms,whichcanbefurtherdecomposedintomechanicalcomponents.Inthissense,themechanicalcomponentsarethefundamentalelementsofmachinery.Onthewhole,mechanicalcomponentscanbeclassifiedasuniversalandspecialcomponents.Bolts,gear,andchainsarethetypicalexamplesoftheuniversalcomponents,whichcanbeusedextensivelyindifferentmachinesacrossvariousindustrialsectors.,MechanicalDesignProcessProductdesignrequiresmuchresearchanddevelopment.Manyconceptsofanideamustbestudied,tried,refined,andtheneitherusedordiscarded.Althoughthecontentofeachengineeringproblemisunique,thedesignersfollowthesimilarprocesstosolvetheproblems.ThecompleteprocessisoftenoutlinedasinFig.1.1.,Fig.1.1DesignProcessModel,RecognitionofNeedSometimes,designbeginswhenadesignerrecognizesaneedanddecidestodosomethingaboutit.Theneedisoftennotevidentatall;recognitionisusuallytriggeredbyaparticularadversecircumstanceorasetofrandomcircumstances,whicharisealmostsimultaneously.Identificationofneedusuallyconsistsofanundefinedandvagueproblemstatement.,DefinitionofProblemDefinitionofproblemisnecessarytofullydefineandunderstandtheproblem,afterwhichitispossibletorestatethegoalinamorereasonableandrealisticwaythantheoriginalproblemstatement.Definitionoftheproblemmustincludeallthespecificationsforthethingthatistobedesigned.Obviousitemsinthespecificationsarethespeeds,feeds,temperaturelimitations,maximumrange,expectedvariationinthevariables,anddimensionalandweightlimitations.,SynthesisThesynthesisisoneinwhichasmanyalternativepossibledesignapproachesaresought,usuallywithoutregardfortheirvalueorquality.Thisisalsosometimescalledtheideationandinventionstepinwhichthelargestpossiblenumberofcreativesolutionsisgenerated.Thesynthesisactivityincludesthespecificationofmaterial,additionofgeometricfeatures,andinclusionofgreaterdimensionaldetailtotheaggregatedesign.,AnalysisAnalysisisamethodofdeterminingordescribingthenatureofsomethingbyseparatingitintoitsparts.Intheprocesstheelements,ornatureofthedesign,areanalyzedtodeterminethefitbetweentheproposeddesignandtheoriginaldesigngoals.,EvaluationEvaluationisthefinalproofofasuccessfuldesignandusuallyinvolvesthetestingofaprototypeinthelaboratory.Herewewishtodiscoverifthedesignreallysatisfiestheneeds.Theabovedescriptionmaygiveanerroneousimpressionthatthisprocesscanbeaccomplishedinalinearfashionaslisted.Onthecontrary,iterationisrequiredwithintheentireprocess,movingfromanystepbacktoanypreviousstep.,PresentationCommunicatingthedesigntoothersisthefinial,vitalpresentationstepinthedesignprocess.Basically,thereareonlythreemeansofcommunication.Thesearethewritten,theoral,andthegraphicalforms.Asuccessfulengineerwillbetechnicallycompetentandversatileinallthreeformsofcommunication.Thecompetentengineershouldnotbeafraidofthepossibilityofnotsucceedinginapresentation.Infact,thegreatestgainsareobtainedbythosewillingtoriskdefeat.,ContentsofMachineryDesignMachinerydesignisanimportanttechnologicalbasiccourseinmechanicalengineeringeducation.Itsobjectiveistoprovidetheconcepts,procedures,data,anddecisionanalysistechniquesnecessarytodesignmachineelementscommonlyfoundinmechanicaldevicesandsystems;todevelopengineeringstudentscompetenceofmachinedesignthatistheprimaryconcernofmachinerymanufacturingandthekeytomanufacturegoodproducts.,1.2Wordsandphrases,machineryn.总称机器，机械trivialadj.琐细的，平常的，微不足道的mechanismn.机构chainn.链(条)，镣铐，一连串，一系列turbinebladen.涡轮机叶片crankshaftn.曲轴propellern.推进者,推进物,尤指轮船、飞机上的螺旋推进器discardv.丢弃,抛弃recognitionn.识别triggerv.引发,引起,触发,vagueadj.含糊的,不清楚的synthesisn.综合ideationn构思能力，思维能力，构思过程aggregateadj.合计的,集合的prototypen.样机，原型erroneousadj.错误的,不正确的iterationn.反复competentadj.有能力的,胜任的versatileadj.通用的,万能的,多才多艺的,1.3ComplexSentenceAnalysis,1Machinerydesigniseithertoformulateanengineeringplanforthesatisfactionofaspecifiedneedortosolveanengineeringproblem.eitheror：或或formulate：明确地表达，阐明机械设计用以阐明满足某种特殊需要的工程计划或解决具体的工程问题。2Itisimportantthatthedesignerbeginsbyidentifyingexactlyhowheorshewillrecognizeasatisfactoryalternative,andhowtodistinguishbetweentwosatisfactoryalternativesinordertoidentifythebest.对于设计者来说，一开始就能准确判定出令人满意的设计方案，并能加以区别以选择最好的，这一点很重要。,3Andthemechanicalsystemisdecomposedintomechanisms,whichcanbefurtherdecomposedintomechanicalcomponents.bedecomposedinto：被分解为which引导一个定语从句，在从句中做主语，指前面的mechanisms。机械系统可以分解为机构,机构又可以进一步分解为机械零件。,1.4Exercise1.4.1TranslatetheFollowingParagraphs,Thepracticeofdesigncanbeoneofthemostexcitingandfulfillingactivitiesthatanengineercanundertake.Thereisastrongsenseofsatisfactionandprideinseeingtheresultsofonescreativeeffortsemergeintoactualproductsandprocessesthatbenefitpeople.Tododesignwellrequiresanumberofcharacteristics.,1.4.2Choosetheproperanswertofillintheblankandtranslatethesentences,1Theyareusinga()shoveltoclearupthestreets.2Manyproductsaremadeby().3Thereisnota()whohasnthadthisproblem.4Machinerydesigninvolvesarangeofdisciplinesinmaterials,(),heat,flow,control,electronicsandproduction.5TheAlliesfinallysmashedtheNaziwar().,Lesson2Mechanisms2.1TextAmechanismisthememberscombinationmorethantwoortwoconnectionswiththememberstorealizetheregulationmotionmadeupbywayoftheactivity.Theyarethecomponentofmachinery.Activityconnectionsbetweentwomembersthathavetherelativemotionarecalledthemotionpairs.,Fig.2.1TypesofCams,2.2Wordsandphrases,mechanismn.机构motionpairs运动副dispositionn.配置；排列machineframe机座，机架coordinaten.坐标motivitymember原动件parametern.参变量drivenmember从动件freedegree自由度categorizev.分类categoryn.种类，逻辑范畴planaradj.平面的，平坦的sphericaladj.球的，球形的spatialadj.空间的locin.locus的复数形式点的轨迹,2.3ComplexSentenceAnalysis,1Themotionspecificpropertyofmechanismchieflydependsontherelativesizebetweenthemember,andthecharacterofmotionpairs,aswellasthemutualdispositionmethodetc.机构的运动特性主要取决于构件间的相对大小、运动副的性质以及相互配置方式等。specificproperty：特性aswellas：不但而且；和一样；和；也，表示递进或并列关系。2Thecriterionwhichdistinguishesthegroups，however，istobefoundinthecharacteristicsofthemotionsofthelinks然而，区别分类的标准在于连杆装置的运动特性。,which引导定语从句，修饰criteriontobefound为不定式被动语态。1inks译为“连杆装置”。3Thischaracteristicmakesitpossibletorepresentthelocusofanychosenpointofaplanarmechanisminitstruesizeandshapeonasingledrawingorfigure有了这一特点，就能够在单个图形或图像上，以实际的尺寸和形状来绘出平面机构的任意选择点的轨迹。makesitpossible：使可能represent：描绘，展现planarmechanism：平面机构。insizeandshape：在大小和形状方面,2.4Exercise：Translatethelineatephrasesandfillinthebrackets.,该机构为平面四连杆机构()，1为机架()，2为原动件()，3、4为从动件()，A为回转副()，属于低副()，B为固定连接()。构件()4中的焊接符号()表示4为一个构件。该机构的自由度数()必须等于原动件数，才能实现确定的运动()。,Lesson3MachineParts(I)3.1TextGearsGearsaredirectcontactbodies，operatinginpairs，thattransmitmotionandforcefromonerotatingshafttoanother,orfromashafttoaslide(rack)，bymeansofsuccessivelyengagingprojectionscalledteethV-beltTherayonandrubberV-beltarewidelyusedforpowertransmissionSuchbeltsaremadeintwoseries：thestandardV-beltandthehighcapacityV-beltThebeltscanbeusedwithshortcenterdistancesandaremadeendlesssothatdifficultywithsplicingdevicesisavoided,ChainDrivesThefirstchain-drivenor“safety”bicycleappearedin1874,andchainswereusedfordrivingtherearwheelsonearlyautomobiles.4Today,astheresultofmoderndesignandproductionmethods,chaindrivesthataremuchsuperiortotheirprototypesareavailable,andthesehavecontributedgreatlytothedevelopmentofefficientagriculturalmachinery,well-drillingequipment,andminingandconstructionmachinery.Sinceabout1930chaindriveshavebecomeincreasinglypopular,especiallyforpowersaws,motorcycle,andescalatorsetc.,3.2Wordsandphrases,Gearn.齿轮projectionn.凸出cycloidaladi.摆线的cycloidalprofile摆线轮廓involuteadi.渐开线的involuteprofile渐开线轮廓conjugateadi.共轭的pinionn.小齿轮dimensionn.量纲matev.啮合engagementn.啮合tangencyn.接触pitchn.齿节,intersectv.相交，交叉dispositionn.排列，配置helicalgear螺旋齿轮spurgear正齿轮，直齿轮wormn.蜗轮，蜗杆bevelgear伞形齿轮，锥齿轮hourglassn沙漏V-beltV型带splicen.连接pulleyn.(皮带)轮grooven.沟，槽tractiveadi.牵引的,clearancen.间隙chaindrive链传动prototypen.模型，原型机sawn.锯escalatorn.自动扶梯rollerchain套筒滚子链条，滚子链beadchain滚珠链条bushingn.套筒sprocketn.链轮strandn.排，列venetianblind威尼斯百叶窗，软百叶窗,3.3ComplexSentenceAnalysis,1Gearsaredirectcontactbodies，operatinginpairs，thattransmitmotionandforcefromonerotatingshafttoanother，orfromashafttoaslide(rack)，bymeansofsuccessivelyengagingprojectionscalledteethoperatinginpairs：分词短语，修饰前面的Gears。that引导的从句，修饰前面的Gears。bymeansof表示“借助”、“通过”的意思齿轮是直接接触的实体，成对使用，在称为齿的凸起的连续啮合作用下，齿轮将运动和力从一根转轴传递到另一根转轴上，或者将运动和力从一根轴传递到滑块(齿条)上。,2Ifaninvolutespurpinionweremadeofrubberandtwisteduniformlysothattheendsrotatedabouttheaxisrelativetooneanother，theelementsoftheteeth，initiallystraightandparalleltotheaxis，wouldbecomehelices.假设一渐开线直齿轮是用橡胶制成的，并且能够均匀扭转，那么，两端就会绕着轴线做相对的转动，这样，开始是直的并平行于轴线的小齿轮上的齿，就变成了螺旋形。weremadeof：“由组成”sothat引导结果状语从句parallelto：“平行于”,3Sufficientclearancemustbeprovidedatthebottomofthegroovetopreventthebeltfrombottomingasitbecomesnarrowerfromwear.atthebottomof“在的底部”preventfromwear“防止磨损”4Today,astheresultofmoderndesignandproductionmethods,chaindrivesthataremuchsuperiortotheirprototypesareavailable,andthesehavecontributedgreatlytothedevelopmentofefficientagriculturalmachinery,well-drillingequipment,andminingandconstructionmachinery.如今，随着现代设计和制造方法的改进，链传动的应用越来越广泛，大大提高了农业机械、钻探设备、矿业和建筑机械的效率。superiorto表示“优于”的意思。and引导的是一句并列句。,3.4Exercise：3.4.1TranslatetheFollowingParagraphs,Agearhavingtoothelementsthatarestraightandparalleltoitsaxisisknownasaspurgear.Aspurpaircanbeusedtoconnectparallelshaftsonly.Parallelshafts,however,canalsobeconnectedbygearsofanothertype,andaspurgearcanbematedwithagearofadifferenttype.,3.4Exercise：3.4.2Writethenameofthefollowingpartsandbriefdescriptionoftherollerchainonthestructureandassemblyrelations.,Fig.3.1Structure,Lesson4MachineParts(II)4.1TextFastener1Fastenersaredeviceswhichpermitoneparttobejoinedtoasecondpartand,hence,theyareinvolvedinalmostalldesigns.Therearethreemainclassificationsoffasteners,whicharedescribedasfollows：(1)Removable.Thistypepermitsthepartstobereadilydisconnectedwithoutdamagingthefastener.Anexampleistheordinarynut-and-boltfastener.(2)Semipermanent.Forthistype,thepartscanbedisconnected,butsomedamageusuallyoccurstothefastener.Onesuchexampleisacotterpin.(3)Permanent.Whenthistypeoffastenerisused,itisintendedthatthepartswillneverbedisassembled.Examplesarerivetedjointsandweldedjoints.,ShaftVirtuallyallmachinescontainshafts.Themostcommonshapeforshaftsiscircularandthecrosssectioncanbeeithersolidorhollow(hollowshaftscanresultinweightsavings).,BearingAbearingcanbedefinedasamemberspecificallydesignedtosupportmovingmachinecomponents.Themostcommonbearingapplicationisthesupportofarotatingshaftthatistransmittingpowerfromonelocationtoanother.Sincethereisalwaysrelativemotionbetweenabearinganditsmatingsurface,frictionisinvolved.Inmanyinstances,suchasthedesignofpulleys,brakes,andclutches,frictionisdesirable.However,inthecaseofbearings,thereductionoffrictionisoneoftheprimeconsiderations：Frictionresultsinlossofpower,thegenerationofheat,andincreasedwearofmatingsurfaces.,Fig.4.1JournalBearing,4.2Wordsandphrases,devicedi5vaisn.器件；设备；装置fastenern.紧固件，紧固零件classificationn.分类，类别removableadi.可移动的，可拆的semipermanentadj.半永久性的cotterpinn.开口销，开尾销disassemblev拆开，分散rivetn.铆钉；v.铆；铆接weldv.焊接，熔接nuisancen.障碍，损害rattlev.drawthebasewithHpencil;checkthedrawinganddarkenthelines.,Methodstoreadviews:(1)Analyzingshapemethod:Breaktheobjectdownintoitsbasicgeometricsolids.(2)Analyzinglinesandplanesmethod:Breaktheobjectintovarioussurfacesandlines.Forexample,likethefollowingFig.5.3,thethreeviewsofaCompositeObject.,Fig.5.3ThreeViewsofCompositeObject,DetailDrawings,Detaildrawings:Itisadrawingthatindicatestheconstruction,size,andtechnicalrequirementsofapart.Itdescribesitsshape,givesthedimensions,providealltheinformationneededtomakethepart.Thecontentsofadetaildrawing:(1)Asufficientnumberofviewstogiveacompleteshapedescriptionoftheexteriorandinteriorconstructionsofthepart.(2)Allthedimensionsneededformanufacturingthepart.(3)Technicalrequirementsincludingtolerances,geometrictolerances,surfaceroughness,materialspecification,heattreatments,andsoon.,AssemblyDrawings,Assemblydrawings:Adrawingthatshowsthepartsofamachineormachineunitassembledintheirrelativeworkingpositioniscalledanassemblydrawing.Thecontentsofanassemblydrawingareasfollows:(1)Asetofviewsshowingthepositionalrelationshipandmutualoperationofthepartsbeingassembled.(2)Afewdimensionsthatareneededtoshowthepositionalrelationshipbetweencriticalparts,thepositioningoftheproductatsite,etc.(3)Technicalrequirementsincludingalltheinformationnecessaryforassembling,checking,andmaintainingthemachine.(4)Itemnumbersforeachpart,theitemlist,andthetitleblock.,5.2Wordsandphrases,graphicsn.制图，图学draftingn.草图，制图drawingn.绘图，制图，图样projectionn.投影dimensionn.尺寸；v.给标注尺寸spatialanalysis空间分析spatialvisualization空间想象horizontalprojection水平投影frontalprojection正投影profileprojection侧投影quadrantn.象限center-linesofsymmetry对称中心线compositeobject组合体detaildrawing零件图assemblydrawing装配图phantomline假想线,5.3ComplexSentenceAnalysis,1GraphicscomestoourvocabularyfromtheGreekwordgrapho,whoseextendedmeaningis“drafting”or“drawing”,thedrawingistheprimarymediumfordevelopingandcommunicatingtechnicalideas.图学一词来源于希腊语grapho，其延伸意义为“绘图”或“图样”。图样是开发和交流技术思想的主要工具。2AccordingtotheChineseNationalStandardofTechnicalDrawings,thefirst-angleprojectionisusedtomakeengineeringdrawingswhileinsomeothercountries,suchasintheUSAandCanada,thethird-angleprojectionisused.依据中国机械制图国家标准，制图采用第一角投影，而其他一些国家像美国和加拿大则采用第三角投影。,3Specialconventions:Representationofmakingthecutalongjointfaceortakingsomepartsapart;representationofshowingpartsseparately;representationofusingphantomlines;exaggeratedrepresentation;simplifiedrepresentation.特殊规定：沿结合面剖切或把某些零件拆开的画法；单独表示零件画法；使用假想线画法；夸大画法；简化画法。,5.4Exercise：TranslatetheFollowingParagraphs,Similartoanoffsetinthatthecutting-planelinestaggers,however,itdiffersinthatthecutting-planelineisoffsetatsomeangleotherthan90.Whenthesectionistakenthesectionalviewisdrawnasifthecutting-planeisrotatedtotheplaneperpendiculartothelineofsight.Thisiswhytherightsidesectionalviewmaysometimesbeelongated(dependingontheshape).Exercise：Drawingthefrontviewtoalignedsection.TheFig.5.4isthetopicandFig.5.5istheanswer.,Fig.5.4TheTopic,Fig.5.5TheAnswer,Lesson6IntroductiontoCAD/CAM/CAPP6.1TextThroughoutthehistoryofourindustrialsociety,manyinventionshavebeenpatentedandwholenewtechnologieshaveevolved.1Perhapsthesingledevelopmentthathasimpactedmanufacturingmorequicklyandsignificantlythananyprevioustechnologyisthedigitalcomputer.Computersarebeingusedincreasinglyforbothdesignanddetailingofengineeringcomponentsinthedrawingoffice.,2Computer-aideddesign(CAD)isdefinedastheapplicationofcomputersandgraphicssoftwaretoaidorenhancetheproductdesignfromconceptualizationtodocumentation.CADismostcommonlyassociatedwiththeuseofaninteractivecomputergraphicssystem,referredtoasaCADsystem.Computer-aideddesignsystemsarepowerfultoolsandareusedinthemechanicaldesignandgeometricmodelingofproductsandcomponents.,ThereareseveralgoodreasonsforusingaCADsystemtosupporttheengineeringdesignfunction:(1)Toincreasetheproductivity.(2)Toimprovethequalityofthedesign.(3)Touniformdesignstandards.(4)Tocreateamanufacturingdatabase.(5)Toeliminateinaccuraciescausedbyhand-copyingofdrawingsandinconsistencybetweendrawings.,ModelsinCADcanbeclassifiedasbeingtwo-dimensionalmodels,two-and-half-dimensionalmodels,orthree-dimensionalmodels.A2-Dmodelrepresentsaflatpartanda3-Dmodelprovidesrepresentationofageneralizedpartshape(asshowninFig.6.1).A-Dmodelcanbeusedtorepresentapartofconstantsectionwithnoside-walldetails.3Themajoradvantageofa-Dmodelisthatitgivesacertainamountof3-Dinformationaboutapartwithouttheneedtocreatethedatabaseofafull3-Dmodel.,Afteraparticulardesignalternativehasbeendeveloped,someformofengineeringanalysismustoftenbeperformedasapartofthedesignprocess.4Theanalysismaytaketheformstress-straincalculations,heattransferanalysis,dynamicsimulationetc.SomeexamplesofthesoftwaretypicallyofferedonCADsystemsaremasspropertiesandFiniteElementMethod(FEM)analysis.Masspropertiesinvolvethecomputationofsuchfeaturesofasolidobjectasitsvolume,surfacearea,weight,andcenterofgravity.FEManalysisisavailableonmostCADsystemstoaidinheattransfer,stress-strainanalysis,dynamiccharacteristics,andotherengineeringcomputations.Presently,manyCADsystemscanautomaticallygeneratethe2-Dor3-DFEMmesheswhichareessentialtoFEManalysis.,(a)Wire-frameModel(b)SurfaceModel,Fig.6.1Three-dimensionModels,CAMcanbedefinedascomputeraidedpreparationmanufacturingincludingdecision-making,processandoperationalplanning,softwaredesigntechniques,andartificialintelligence,andmanufacturingwithdifferenttypesofautomation(NCmachine,NCmachinecenters,NCmachiningcells,NCflexiblemanufacturingsystems),anddifferenttypesofrealization(CNCsingleunittechnology,DNCgrouptechnology).TheCAMcoversgrouptechnology,manufacturingdatabase,automatedandtolerance.Fig.6.2illustrates