机械设计专业的毕业设计(英文版)VIP免费

MechanicalEngineeringIntroductiontoMechanicalEngineeringMechanicalengineeringisthebranchofengineeringthatdealswithmachinesandtheproductionofpower.Itisparticularlyconcernedwithforcesandmotion.HistoryofMechanicalEngineeringTheinventionofthesteamengineinthelatterpartofthe18thcentury,providingakeysourceofpowerfortheIndustrialRevolution,gaveanenormousimpetustothedevelopmentofmachineryofalltypes.Asaresultanewmajorclassificationofengineering,separatefromcivilengineeringanddealingwithtoolsandmachines,developed,receivingformalrecognitionin1847inthefoundingoftheInstitutionofMechanicalEngineersinBirmingham,England.Mechanicalengineeringhasevolvedfromthepracticebythemechanicofanartbasedlargelyontrialanderrortotheapplicationbytheprofessionalengineerofthescientificmethodinresearch,design,andproduction.Thedemandforincreasedefficiency,inthewidestsense,iscontinuallyraisingthequalityofworkexpectedfromamechanicalengineerandrequiringofhimahigherdegreeofeducationandtraining.NotonlymustmachinesrunmoreeconomicallybutcapitalCostsalsomustbeminimized.FieldsofMechanicalEngineeringDevelopmentofmachinesfortheproductionofgoodsthehighmaterialstandardoflivinginthedevelopedcountriesowesmuchtothemachinerymadepossiblebymechanicalengineering.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.Themechanicalengineerisalsoresponsibleforthemuchsmallerinternalcombusti...