机械设计毕业设计翻译.docx
《机械设计毕业设计翻译.docx》由会员分享,可在线阅读,更多相关《机械设计毕业设计翻译.docx(11页珍藏版)》请在冰豆网上搜索。
![机械设计毕业设计翻译.docx](https://file1.bdocx.com/fileroot1/2023-4/21/264d6f44-516f-4068-b407-34795711d362/264d6f44-516f-4068-b407-34795711d3621.gif)
机械设计毕业设计翻译
MechanicalEngineering
IntroductiontoMechanicalEngineering
Mechanicalengineeringisthebranchofengineeringthatdealswithmachinesandtheproductionofpower.Itisparticularlyconcernedwithforcesandmotion.
HistoryofMechanicalEngineering
Theinventionofthesteamengineinthelatterpartofthe18thcentury,providingakeysourceofpowerfortheIndustrialRevolution,gaveanenormousimpetustothedevelopmentofmachineryofalltypes.Asaresultanewmajorclassificationofengineering,separatefromcivilengineeringanddealingwithtoolsandmachines,developed,receivingformalrecognitionin1847inthefoundingoftheInstitutionofMechanicalEngineersinBirmingham,England.
Mechanicalengineeringhasevolvedfromthepracticebythemechanicofanartbasedlargelyontrialanderrortotheapplicationbytheprofessionalengineerofthescientificmethodinresearch,design,andproduction.
Thedemandforincreasedefficiency,inthewidestsense,iscontinuallyraisingthequalityofworkexpectedfromamechanicalengineerandrequiringofhimahigherdegreeofeducationandtraining.NotonlymustmachinesrunmoreeconomicallybutcapitalCostsalsomustbeminimized.
FieldsofMechanicalEngineering
Developmentofmachinesfortheproductionofgoodsthehighmaterialstandardoflivinginthedevelopedcountriesowesmuchtothemachinerymadepossiblebymechanicalengineering.Themechanicalengineercontinuallyinventsmachinestoproducegoodsanddevelopsmachinetoolsofincreasingaccuracyandcomplexitytobuildthemachines.
Theprincipallinesofdevelopmentofmachineryhavebeenanincreaseinthespeedofoperationtoobtainhighratesofproduction,improvementinaccuracytoobtainqualityandeconomyintheproduct,andminimizationofoperatingcosts.Thesethreerequirementshaveledtotheevolutionofcomplexcontrolsystems.
Themostsuccessfulproductionmachineryisthatinwhichthemechanicaldesignofthemachineiscloselyintegratedwiththecontrolsystem,whetherthelatterismechanicalorelectricalinnature.Amoderntransferline(conveyor)forthemanufactureofautomobileenginesisagoodexampleofthemechanizationofacomplexseriesofmanufacturingprocesses.Developmentsareinhandtoautomateproductionmachineryfurther,usingcomputerstostoreandprocessthevastamountofdatarequiredformanufacturingavarietyofcomponentswithasmallnumberofversatilemachinetools.Oneaimisacompletelyautomatedmachineshopforbatchproduction,operatingonathreeshiftbasisbutattendedbyastaffforonlyoneshiftperday.
DevelopmentofmachinesfortheproductionofpowerProductionmachinerypresupposeanamplesupplyofpower.Thesteamengineprovidedthefirstpracticalmeansofgeneratingpowerfromheattoaugmenttheoldsourcesofpowerfrommuscle,wind,andwaterOneofthefirstchallengestothenewprofessionofmechanicalengineeringwastoincreasethermalefficienciesandpower;thiswasdoneprincipallybythedevelopmentofthesteamturbineandassociatedlargesteamboilers.The20thcenturyhaswitnessedacontinuedrapidgrowthinthepoweroutputofturbinesfordrivingelectricgenerators,togetherwithasteadyincreaseinthermalefficiencyandreductionincapitalcostperkilowattoflargepowerstations.Finally,mechanicalengineersacquiredtheresourceofnuclearenergy,whoseapplicationhasdemandedanexceptionalstandardofreliabilityandsafetyinvolvingthesolutionofentirelynewproblems-Thecontrolsystemsoflargepowerplankandcompletenuclearpowerstationshavebecomehighlysophisticatednetworksofelectronic,fluidic.Electric,hydraulic,andmechanicalcomponents,ailoftheseinvolvingmeprovinceofthemechanicalengineer.
Themechanicalengineerisalsoresponsibleforthemuchsmallerinternalcombustionengines,bothreciprocating(gasolineanddiesel)androtary(gas-turbineandWankel)engines,withtheirwidespreadtransportapplications-Inthetransportationfieldgenerally,inairandspaceaswellasonlandandsea.themechanicalengineerhascreatedtheequipmentandthepowerplant,collaboratingincreasinglywiththeelectricalengineer,especiallyinthedevelopmentofsuitablecontrolsystems.
DevelopmentofmilitaryweaponsTheskillsappliedtowarbythemechanicalengineeraresimilartothoserequiredincivilianapplications,thoughthepurposeistoenhancedestructivepowerratherthantoraisecreativeefficiency.Thedemandsofwarhavechanneledhugeresourcesintotechnicalfields,however,andledtodevelopmentsthathaveprofoundbenefitsinpeace.Jetaircraftandnuclearreactorsarenotableexamples.
BiaengineeringBioengineeringisarelativelynewanddistinctfieldofmechanicalengineeringthatincludestheprovisionofmachinestoreplaceoraugmentthefunctionsofthehumanbodyandofequipmentforuseinmedicaltreatment.Artificiallimbshavebeendevelopedincorporatingsuchlifelikefunctionsaspoweredmotionandtouchfeedback.Developmentisrapidinthedirectionofartificialspare-partsurgery.Sophisticatedheart-lungmachinesandsimilarequipmentpermitoperationsofincreasingcomplexityandpermitthevitalfunctionsinseriouslyinjuredordiseasedpatientstobemaintained.
EnvironmentalcontrolSomeoftheearliesteffortsofmechanicalengineerswereaimedatcontrollingman'senvironmentbypumpingwatertodrainorirrigatelandandbyventilatingmines.Theubiquitousrefrigeratingandair-conditioningplantsofthemodemagearebasedonareversedheatengine,wherethesupplyofpower"pumps"heatfromthecoldregiontothewarmerexterior.
Manyoftheproductsofmechanicalengineering,togetherwithtechnologicaldevelopmentsinotherfields,havesideeffectsontheenvironmentandgiverisetonoise,thepollutionofwaterandair,andthederelictionoflandandscenery.Therateofproduction,bothofgoodsandpower,isrisingsorapidlythatregenerationbynaturalforcescannolongerkeeppace.Arapidlygrowingfieldformechanicalengineersandothersisenvironmentalcontrol,comprisingthedevelopmentofmachinesandprocessesthatwillproducefewerpollutantsandofnewequipmentandtechniquesthatcanreduceorremovethepollutionalreadygenerated.
FunctionsofMechanicalEngineering
Fourfunctionsofthemechanicalengineering,commontoallthefieldsmentioned,arecited.Thefirstistheunderstandingofanddealingwiththebasesofmechanicalscience.Theseincludedynamics,concerningtherelationbetweenforcesandmotion,suchasinvibration;automaticcontrol;thermodynamics,dealingwiththerelationsamongthevariousformsofheat,energy,andpower;fluidflow;heattransfer;lubrication;andpropertiesofmaterials.
Secondisthesequenceofresearch,design,anddevelopment.Thisfunctionattemptstobringaboutthechangesnecessarytomeetpresentandfutureneeds.Suchworkrequiresnotonlyadearunderstandingofmechanicalscienceandanabilitytoanalyzeacomplexsystemintoitsbasicfactors,butalsotheoriginalitytosynthesizeandinvent.
Thirdisproductionofproductsandpower,whichembracesplanning,operation,andmaintenance.Thegoalistoproducethemaximumvaluewiththeminimuminvestmentandcostwhilemaintainingorenhancinglongertermviabilityandreputationoftheenterpriseortheinstitution.
Fourthisthecoordinatingfunctioningofthemechanicalengineering,includingmanagement,consulting,and,insomecases,marketing.
Inallofthesefunctionsthereisalongcontinuingtrendtowardtheuseofscientificinsteadoftraditionalorintuitivemethods,anaspectoftheever-growingprofessionalismofmechanicalengineering.Operationsresearch,valueengineering,andPABLA(problemanalysisbylogicalapproach)aretypicaltitlesofsuchnewrationalizedapproaches.Creativity,however,cannotberationalized.Theabilitytotaketheimportantandunexpectedstepthatopensupnewsolutionsremainsinmechanicalengineering,aselsewhere,largelyapersonalandspontaneouscharacteristic.
TheFutureofMechanicalEngineering
Thenumberofmechanicalengineerscontinuestogrowasrapidlyasever,whilethedurationandqualityoftheirtrainingincreases.Thereisagrowing:
awareness,however,amongengineersandinthecommunityatlargethattheexponentialincreaseinpopulationandlivingstandardsisraisingformidableproblemsinpollutionoftheenvironmentandtheexhaustionofnaturalresources;thisclearlyheightenstheneedforallofthetechnicalprofessionstoconsiderthelong-termsocialeffectsofdiscoveriesanddevelopments.-Therewillbeanincreasingdemandformechanicalengineeringskillstoprovideforman'sneedswhilereducingtoaminimumtheconsumptionofscarcerawmaterialsandmaintainingasatisfactoryenvironment.
IntroductiontoDesign
TheMeaningofDesign
Todesignistoformulateaplanforthesatisfactionofahumanneed.Theparticularneedtobesatisfiedmaybequitewelldefinedfromthebeginning.Herearetwoexamplesinwhichneedsarewelldefined:
1.Howcanweobtainlargequantitiesofpowercleanly,safely,andeconomical/withoutusingfossilfuelsandwithoutdamagingthesurfaceoftheearth?
2.Thisgearshaftisgivingtrouble;therehavebeeneightfailuresinthelastsixweeks.Dosomethingaboutit.
Ontheotherhand,thestatementofaparticularneedtobesatisfiedmaybesonebulousandilldefinedthataconsiderableamountofthoughtandeffortisnecessaryin(ordertostateitdearlyasaproblemrequiringasolution.Herearetwoexamples.-
1.Lotsofpeoplearekilledinairplaneaccidents.
2.Inbigcitiestherearetoomanyautomobilesonthestreetsandhighways.
Thissecondtypeofdesigns