专业英语之英语(原文).docools>Bearings、oolsMachiningaimstogeneratetheshapeofwork-piecefromasolidbody,ortoimprovethetolerancesandsurfaceflnishofapreviouslyformedwork-piece,,tolerances,,machiningremovesmaterials,,developmentsoftenaimatreducingor-ifatallpossible-eliminatingmachining,,machininghaslostsomeimportantmarkets,yet,atthesametime,-oolsintheUniteStates(ofwhichsome5%werenumericallycontrolled)andthatlaborandoverheadcostsamountedto$125billion,or3%-purposemachines,andothersareusedtoperformhighlyspecializedoperations・oolistheenginelathe,-piecemustbefirmlyheld,frequentlyinachuck・Barsmayalsobeheldincollets,whichconsistofasplitbushingpushedorpulledagainstaconicalsurface・,usuallyincorporatingchangegearsandavariable--(horizontallyandvertically).Thetoolpostismountedonacarriage,,theapronofthecarriage,maybeengagedwiththefeedrodtogivecontinuousfeedmotion,orwithaleadscrewforcuttingofthreads・Verylongwork-piecesaresecuredagainstexcessivedeflectionbytwofingerscenterrestorsteadyrestboltedtothelathe;afollowrestisclampedtothecarriage・poundtoolrestwhichincorporatesaslidethatcanbesetatanyangle;thus,conicalsu
专业英语之英语(原文) 来自淘豆网m.daumloan.com转载请标明出处.
