资源描述：
《机械毕业英语论文翻译5000字-车床.doc》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。
1、英文原文1LathesLathesaremachinetoolsdesignedprimarilytodoturning,facingandboring,Verylittleturningisdoneonothertypesofmachinetools,andnonecandoitwithequalfacility.Becauselathesalsocandodrillingandreaming,theirversatilitypermitsseveraloperationstobedonewithasinglesetu
2、poftheworkpiece.Consequently,morelathesofvarioustypesareusedinmanufacturingthananyothermachinetool.Theessentialcomponentsofalathearethebed,headstockassembly,tailstockassembly,andtheleadscrewandfeedrod.Thebedisthebackboneofalathe.Itusuallyismadeofwellnormalizedora
3、gedgrayornodularcastironandprovidessheavy,rigidframeonwhichalltheotherbasiccomponentsaremounted.Twosetsofparallel,longitudinalways,innerandouter,arecontainedonthebed,usuallyontheupperside.SomemakersuseaninvertedV-shapeforallfourways,whereasothersutilizeoneinverte
4、dVandoneflatwayinoneorbothsets,Theyareprecision-machinedtoassureaccuracyofalignment.Onmostmodernlathesthewayaresurface-hardenedtoresistwearandabrasion,butprecautionshouldbetakeninoperatingalathetoassurethatthewaysarenotdamaged.Anyinaccuracyinthemusuallymeansthatt
5、heaccuracyoftheentirelatheisdestroyed.Theheadstockismountedinafoxedpositionontheinnerways,usuallyattheleftendofthebed.Itprovidesapoweredmeansofrotatingthewordatvariousspeeds.Essentially,itconsistsofahollowspindle,mountedinaccuratebearings,andasetoftransmissiongea
6、rs-similartoatrucktransmission—throughwhichthespindlecanberotatedatanumberofspeeds.Mostlathesprovidefrom8to18speeds,usuallyinageometricratio,andonmodernlathesallthespeedscanbeobtainedmerelybymovingfromtwotofourlevers.Anincreasingtrendistoprovideacontinuouslyvaria
7、blespeedrangethroughelectricalormechanicaldrives.Becausetheaccuracyofalatheisgreatlydependentonthespindle,itisofheavyconstructionandmountedinheavybearings,usuallypreloadedtaperedrollerorballtypes.Thespindlehasaholeextendingthroughitslength,throughwhichlongbarstoc
8、kcanbefed.Thesizeofmaximumsizeofbarstockthatcanbemachinedwhenthematerialmustbefedthroughspindle.Thetailsticdassemblyconsists,essentially,ofthreeparts.Alowercas
