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1、课程名称学院名称班级专业学生姓名学号任课(指导)老师LathesLathesaremachinetoolsdesignedprimarilytodoturning,facingandboring,Verylittleturningisdoneonothertypesofmachinetools,andnonecandoitwithequalfacility.Becauselathesalsocandodrillingandreaming,theirversatilitypermitsseveralope
2、rationstobedonewithasinglesetupoftheworkpiece.Consequently,morelathesofvarioustypesareusedinmanufacturingthananyothermachinetool.Theessentialcomponentsofalathearethebed,headstockassembly,tailstockassembly,andtheleadscrewandfeedrod.Thebedisthebackboneofal
3、athe.Itusuallyismadeofwellnormalizedoragedgrayornodularcastironandprovidessheavy,rigidframeonwhichalltheotherbasiccomponentsaremounted.Twosetsofparallel,longitudinalways,innerandouter,arecontainedonthebed,usuallyontheupperside.SomemakersuseaninvertedV-sh
4、apeforallfourways,whereasothersutilizeoneinvertedVandoneflatwayinoneorbothsets,Theyareprecision-machinedtoassureaccuracyofalignment.Onmostmodernlathesthewayaresurface-hardenedtoresistwearandabrasion,butprecautionshouldbetakeninoperatingalathetoassurethat
5、thewaysarenotdamaged.Anyinaccuracyinthemusuallymeansthattheaccuracyoftheentirelatheisdestroyed.Theheadstockismountedinafoxedpositionontheinnerways,usuallyattheleftendofthebed.Itprovidesapoweredmeansofrotatingthewordatvariousspeeds.Essentially,itconsistso
6、fahollowspindle,mountedinaccuratebearings,andasetoftransmissiongears-similartoatrucktransmission—throughwhichthespindlecanberotatedatanumberofspeeds.Mostlathesprovidefrom8to18speeds,usuallyinageometricratio,andonmodernlathesallthespeedscanbeobtainedmerel
7、ybymovingfromtwotofourlevers.Anincreasingtrendistoprovideacontinuouslyvariablespeedrangethroughelectricalormechanicaldrives.Becausetheaccuracyofalatheisgreatlydependentonthespindle,itisofheavyconstructionandmountedinheavybearings,usuallypreloadedtaperedr
8、ollerorballtypes.Thespindlehasaholeextendingthroughitslength,throughwhichlongbarstockcanbefed.Thesizeofmaximumsizeofbarstockthatcanbemachinedwhenthematerialmustbefedthroughspindle.Thetailsticdassemblyconsists,essentially,o