资源描述:
《机械制造专业外文翻译--机构与机器》由会员上传分享,免费在线阅读,更多相关内容在工程资料-天天文库。
1、外文原文:MechanismandMachinesAsystemthattransmitsforcesinapredeterminedmannertoaccomplishspecificobjectivesmaybeconsideredamachine.Amechanismmaybedefinedinasimilarmanner,butthetermmechanismisusuallyappliedtoasystemwheretheprincipalfunctionistotransmitmotion.Kinema
2、ticsisthestudyofmotioninmechanism,whiletheanalysisofforceandtorquesinmachinediscalleddynamics.Oncetheneedforamachineormechanismwithgivencharacteristicsisidentified,thedesignprocessbegins.Detailedanalysisofdisplacements,velocities,andaccelerationsisusuallyrequi
3、red.Thispartofthedesignprocessisthenfollowedbyanalysisofforceandtorques.Thedesignprocessmaycontinuelongafterfirstmodelhavebeenproduceandincluderedesignsofcomponentthataffectvelocities,accelerations,force,andtorques.Inordertosuccessfullycompeteformyeartoyear,mo
4、stmanufacturersmustcontinuouslymodifytheirproductandtheirmethodsofproduction.Increasesinproductionrate,upgradingofproductperformance,redesignforcostandweightreduction,andmotionanalysisofnewproductlinesarefrequentlyrequired.Successmayhingeonthecorrectkinematica
5、nddynamicanalysisoftheproblem.Manyofthebasiclinkageconfigurationshavebeenincorporateintomachinesdesignedcenturiesago,andthetermweusetodescribethenhavechangeovertheyear.Thus,definitionsandterminologywillnotbeconsistentthroughoutthetechnicalliterature・Inmostcase
6、s,however,meaningswillbeclearformthecontextofthedescriptivematte匚Afewtermsofparticularinteresttothestudyofkinematicanddynamicsofmachinesaredefinebelow.LinkAlinkisoneoftherigidbodiesormembersjoinedtogethertoformakinematicchain.Thetermrigidlinkorsometimessimplyl
7、inkisanidealizationusedinthestudyofthatdoesnotconsidersmalldeflectionsduetostrainsinmachinemembers.Aperfectlyrigidorinextensiblelinkcanexistonlyasatextbooktypeofmodelofarealmachinemember.Fortypicalmachinepart,maximumdimensionchangesareofonlyaone-thousandthofth
8、epartlength.Wearejustifiedinneglectingthissmallmotionwhenconsideringthemuchgreatermotioncharacteristicofmostmechanisms-Thewordlinkisusedinageneralsensetoincludecams,gears,andotherm