机械专业英语

机械专业英语第一篇：机械专业英语机械专业英语杨亚炬20XX0334506机电103班考虑磨削力的磁悬浮磨床电主轴转子系统动态特性分析摘要:以电磁轴承支承的磨床也主轴为研究对象，建立了转子的弹性支承模型，对其进行了模态分析，得出转子固有频率随支承刚度变化的规律;对施加磨削力时转子的稳态响应特性进行了分析，根据危险界面的节点位移，初步确定了主轴系统的稳定性。关键词:电磁轴承支承系统;磨床电主轴;模态分析;稳态响应特性引言电磁轴承具有无摩擦、元磨损、高速度、高精度及可长期免维护等优点，因此被广泛应用于高速旋转类机械中。采用电磁轴承支承的磨床电主轴是典型的机电一体化系统，由于磨削过程的复杂性，其支承主轴系统的影响与其他轴承相比更为突出[1刀。转子的动态特性是电磁轴承支承特性与转子结构动力学特性综合作用的结果。在对转子实施控制之前，研究转子本身的动力学行为对控制系统的设计是很重要的时。本文以某电磁轴承支承的磨床电主轴为研究对象，建立了转子的弹性支承模型，对其进行了模态分析和施加磨削力时的稳态响应特性分析。轴、砂轮连接杆、前后径向轴颈套、前后平衡环、止推盘和隔磁环等组成，其他部件与转轴之间采用过盈连接。转子总重5.90kg，总长507mm，稳定悬浮时转子和径向轴承之间的间隙为0.2mm，轴向轴承1.砂轮2传感器3.前辅助轴承4.前径向轴承5.转轴6.轴向轴承7.冷却水套8.电机部分9.后径向轴承10.后辅助轴承间隙为0.3mm。建立有限元模型电磁轴承支承为典型的弹性支承，有限元分析模型采用16个弹簧单元模拟径向电磁轴承的16个磁极。止推盘两侧分别采用8个弹簧转轴根据转子的结构形式，用ANSYS建立起转子的实体有限元分析模型，模态分析支承刚度对转子固有频率的影晌根据转子的有限元分析模型，用ANSYS对其进行模态分析[5J。忽略弹簧单元的阻尼，支承刚度在5X106~lXI09N/m范围内变化阶模态，得到转子的正进动固有频率和负进动固有频率，进一步研究临界转速时，首先剔除负进动固有频率[6J。可以得到转轴前四阶固有频率随刚度变化曲线,转子的正进动固有频率随支承刚度的增大而增大，且转子的低阶固有频率随支承刚度增加的幅度较大。当支承刚度增大到1.6X108N/m时，转子的2~4阶固有频率已无多模态分析完毕后，将磨削激振力施加于砂轮处进行谐响应分析，在砂轮外圆节点7746处施加Y方向力(实部为88.328N、虚部为1.9737N)和Z方向力(实部为1.9737N、虚部为88.328N)，这样磨削力为一简谐力。COMBIN14单元的刚度取2.0X107N/m，为分析转子在高频段的响应，将激振力的频率范围扩大至0~1600Hz，分20XX载荷步进行谐响应分析。当主轴工作在30000r/min(对应额定工作频率500.0Hz)、48OOOr/min(对应最高工作频率800.OHz)，即转速处于一阶与二阶临界转速之间时，由转子的二阶振型(图5)可以看出，转子在砂轮、前保护轴承、前径向轴承和后径向轴承处的中心截面为危险截面。图7~图10分别为砂轮、前保护轴承、前径向轴承和后径向轴承处的振动幅值一频率响应后径向轴承处节点4484振动幅值一频率响应曲线移增大幅值在一阶固有频率处最小，二阶固有频率处最大，三阶固有频率处次之。磨床电主轴的结构参数如下:转子与前后保护轴承的间隙为O.lmm，与前后径向轴承的间隙为0.2mm。由表3可知，当激振力频率达到转子一阶、三阶固有频率时，转子产生的共振位移在转曲线，在有限元模型上分别对应节点7746、7818、7559和4484的振动幅值频率响应。各危险截面的节点Y方向位移如表3所示。当激振力频率达到转子的固有频率时，转子的位移(振动幅值)会突然增大，通过前三阶的幅频响应曲线可以看出，转子位子间隙范围之内;但达到转子二阶固有频率时，转子产生的共振位移会超出间隙要求，使得转子与轴承碰撞，发生危险，因此应避免激振力频率达到转子的二阶固有频率。由转子的二阶振型可以看出，转子在后保护轴承处的径向位移小于后径向轴承处的径向位移，故可判定后保护轴承处在Y方向的位移小于2.0X10一7m。各危险截面的节点位移均在间隙范围内，因此可初步判定转子在额定转速和最高转速下工作时，给其施加Fn=88.328N、Ft=1.9737N的磨削力，可稳定工作。结论(1)完全弹性支承下，电主轴转子固有频率的总体变化趋势随支承刚度的增大而增大，并且在支承刚度较低时，固有频率随支承刚度的变化较大。当支承刚度到达一定值时，转子的前四阶固有频率趋于稳定，在设计控制系统时可控制轴承的刚度高于此值，以便转子具有稳定的临界转速。(2)在施加了磨削激振力后，通过幅值频率响应分析确定了几个危险界面的节点位移，可初步判断主轴系统的稳定性。DynamicAnalysisforElectricSpindleRotorSystemofMagneticLevitationGrinderConsideringGrindingForceAbstract:Thispaperbui1tanelasticbearingmodelfortherotorofgrinderelectricspindlesupportedbyelectromagnetbearingandanalyzedthemodeoftherotor,educedthelawsabouttherotorinherentfrequencieschangingalongwithbearingstiffness.Then,itanalyzedsteadystateresponsecharacteristicsoftherotorwhileapplyinggrindingforce.Accordingtothenodedisplacementsofdangerinterface,stabilityofspindlesystemisensuredinitially.Keywords:supportingsystemofelectromagnetbearing;grinderelectricspindle;modeanalysis;steadystateresponsecharacteristics.IntroductionElectromagneticbearingswithnofriction,wearyuan,high-speed,highprecisionandlong-termmaintenance-free,etc.,itiswidelyusedinhigh-speedrotatingmachinery.Theelectromagneticbearinggrinderelectricspindleisatypicalmechatronicsystems,duetothecomplexityofthegrindingprocess,thesupportingspindlesystemcomparedwithotherbearingmoreprominent[1knife.Thedynamiccharacteristicsoftherotortheelectromagneticbearingcharacteristicsandrotorstructuredynamicscombinedresult.Beforecontroloftherotorembodiment,thestudyrotordynamicbehaviorofthecontrolsystemdesignisveryimportant.Anelectromagneticbearinggrinderelectricspindlerotorelasticsupportmodel,itsmodalanalysisandsteady-stateresponsecharacteristicsinthegrindingforceisapplied.Shaft,wheelconnectingrod,frontandrearradialjournalcover,frontandrearstabilizerring,thrustplate,andeveryothermagneticinterferenceconnectionbetweentheothercomponentsandtheshaft.Therotortotalweightof5.90kg,Totallength507mm,stablesuspensionoftherotorandtheradialbearinggapof0.2mm,andtheaxialbearingwheelsensor3.Formerauxiliarybearingfrontradialbearing5.Shaftaxialbearingcoolingwaterjacketmotorsection9afterradialbearing10aftertheauxiliarybearingclearanceof0.3mm.FiniteelementmodelTheelectromagneticbearingthetypicalelasticsupport,finiteelementanalysismodelwith16springelementtosimulatetheradialmagneticbearing16pole.Onbothsidesofthethrustplate8springpivotEstablishedwithANSYSbasedonthestructureoftherotor,therotorsolidfiniteelementanalysismodel,ModalAnalysisSupportstiffnessIMPACTnaturalfrequencyoftherotorbasedonthefiniteelementanalysismodeloftherotor,modalanalysisusingANSYSits[5J.Thedampingofthespringelementisignored,thethesupportstiffness5X106~lXI09N/mrangeordermodalrotorisprecessionnaturalfrequenciesandnegativeprecessionnaturalfrequency,furtherstudyofthecriticalspeed,thefirstnaturalfrequency[excludingthenegativeprecession6J.Cangettheshaftfirstfournaturalfrequencyofthecurvewiththechangeinstiffnessoftherotorisprecessionnaturalfrequencywiththesupportstiffnessincreases,andtherateofincreaseofthelow-ordernaturalfrequencyoftherotorwiththebearingstiffness.The2-4ordernaturalfrequencyoftherotorFoundwhenthesupportingstiffnessincreasesto1.6X108N/m,Modalanalysisaftergrindingexcitingforceisappliedatthewheelattheharmonicresponseanalysis,theYdirectionoftheforceappliedtothewheelouternode7746(88328Nrealpart,imaginarypart19737N),andZdirectionsforce(therealpartof9737N,theimaginarypartofthe88328N),sothatthegrindingforceofasimpleharmonicforce.COMBIN14elementstiffnesstake2.0x107N/mfortheanalysisoftheresponseoftherotorathighfrequencies,thefrequencyrangeoftheexcitationforceisexpandedto0to1600Hz,20XXoadstepharmonicresponseanalysis.Spindle30000r/min(correspondingtothenominaloperatingfrequency500.0Hz),of48OOOr/min(correspondingtothemaximumoperatingfrequencyof800OHZ)thatspeedinthefirst-orderandsecond-ordercriticalspeed,thesecondrotorvibrationtype(Figure5)canbeseen,therotorwheel,thefrontprotectivebearings,theradialbearingandtherearradialbearingatthecenterofasectionalviewofthedangeroussection.Figures7to10respectivelyforthewheel,thefrontprotectivebearings,thefrontradialbearingandaradialbearingatafrequencyresponseofthevibrationamplitudeofthevibrationamplitudeoftheradialbearingatthenode4484frequencyresponsecurveshiftincreasedamplitudeinaThenaturalfrequenciesattheminimum,followedbythenaturalfrequencyofthesecond-order,third-ordernaturalfrequency.OfGrinderSpindlestructureparametersareasfollows:rotorprotectionbeforeandafterbearingclearanceO.lmmthefrontandrearradialbearingclearanceof0.2mm.SeenfromTable3,whenthefrequencyoftheexcitationforcetotherotor-order,third-ordernaturalfrequency,theresonancegeneratedbytherotordisplacementinthetransfercurveinthefiniteelementmodel,respectivelycorrespondingtothenodes7746,7818,7559and4484,theamplitudeofvibrationfrequencyresponse.ThenodesintheYdirectionofthedangeroussectionofthedisplacementshowninTable3.Whenthefrequencyoftheexcitationforceisreachedwhenthenaturalfrequencyoftherotor,therotordisplacement(vibrationamplitude)willsuddenlyincreases,frequencyresponsecurveofthewebthroughthefirstthreecanbeseen,withinthescopeoftheclearanceoftherotorcharts;butreachedrotorSecondOrdernaturalfrequencyoftherotoroftheresonancedisplacementwillexceedthespacingrequirements,sothattherotorandthebearingcollisiondanger,thesecondnaturalfrequencyoftheexcitingforcethefrequencyoftherotorshouldthereforebeavoided.Bythesecond-ordervibrationoftherotorcanbeseen,theradialdisplacementoftherotorafterprotectionoftheradialdisplacementofthebearingislessthantheradialbearingatthedisplacementofthebearingsintheYdirection,itcanbedeterminedafterprotectionSmaller2.0X10am.OfthedangeroussectionofthenodaldisplacementsgappreliminarydeterminationrotoratratedspeedandmaximumSpeedworkwhenappliedtoitsFn=88.328NFT=9737Ngrindingforcecanworkstably.Conclusions(1)fullyresilientsupport,theoveralltrendofthenaturalfrequencyoftheelectro-spindlerotorwithbearingstiffnessincreases,andthesupportingrigidityislow,thelargerthechangeofthenaturalfrequencywiththesupportstiffness.Whenthesupportingrigidityreachesacertainvalue,thefirstfournaturalfrequenciesoftherotorisstabilizedinthedesignofthecontrolsystemcancontrolthestiffnessofthebearingishigherthanthisvalue,thestabilityofthecriticalspeedfortherotorhaving.(2)Inthegrindingexcitingforceisappliedbytheamplitudefrequencyresponseanalysisidentifiedseveralriskinterfacenodaldisplacementscandeterminetheinitialstabilityofthespindlesystem.第二篇：大学机械专业英语总结Unit11Machinetoolshaveevoledfromtheearlyfoot-poweredlathesoftheEgyptiansandJohnWilkinson’sboringmill.Mostmachiningoperationsproducepartsofdifferinggeometry.Flatorplainsurfacesarefrequentlyrequired.Multiple-edgedtoolscanalsobeused.ThebasicoperationsperformedonanenginelatheareillustratedinFig11-3.Thoseoperationsperformedonexternalsurfaceswithasinglepointcuttingtoolarecalledturning.Theobjectiveofboringaholeinalatheis:1.Toenlargethehole2,Tomachinetheholetothedesireddiameter.3.Toaccuratelylocatethepositionofthehole.4.Toobtionasmothsurfacefinishinthehole.Unit12Broachingisaprocessforinternalorexternalmachiningoffalt,round,orcontouredsurfaces.Sawingisthepartingofmaterialbyusingmetaldisks,blades,bands,orabrasivedisksasthecuttingtools,Reamingisamachiningprocessforenlarging,smoothingand/oraccuratelysizingexistingholesbymeansofmultiedgeflutescuttingtools.Unit13Weldingisessentialtotheexpansionandproductivityofourindustries.Electroplatingisaprocessinwhichametalisdepositedontoametallicsubstrate.Solderingisthejoiningofmetalsbycausingalower-melting-pointmetaltowetoralloywiththejointsurfacesandthenfreezeinplace.Cleaningoperationsareperformedbothpreparatorytoandafterfinishingoperations.Unit14Lathesaredesignedtorotatetheworkpieceandfeedthecuttingtoolinthedirectionnecessarytogeneratetherequiredmachinedsurface.Vertical-boringmachinehorizontal-boringmachineplanningmachinehorizontal-millingmachinevertical-millingmachineUnit15AJMremovesmaterialthroughthemechanicalcationofafocusedstreamofabrasiveladengas.USMisamechanicalmaterialremovalprocesswhichisusedtogenerateholesandcavitiesinhardorbrittleworkpieces.ECMisaprocessthatremovesmaterialthroughtheptincipleofeiectrolysis.Unit16Grouptechnologyisaveryimportantmethodologyintoday’smanufacturingenvironment,particularlyforbatchproduction,andisbecomingincreasinglysignificant.Forpartstobegroupedbasedoneitherdesigncharacteristicsandfeatuersormanufacturingprocesses,theymustbeclassifiedintopredeterminedcategoriesandcodedforretrievalanduse.Unit17Flexibilityisanimportantcharacteristicinthemodernmanufacturingsetting.Cellularmanufacturingistheconceptoforganizingplantfacilitiesandprocessplanningforfamily-of-partmanufactuer.Machinecentersoriginstedoutoftheircapabilitytoperformavarietyofmachiningoperationsonaworkpiecebychangingtheirowncuttingtools.SoftwareisthevitalinvisibleelementthanactuallydrivestheFMS.TherearetwobasiclevelsofsoftwarerequiredforanFMS:1:operatingsystem2:applicationsoftwareUnit18Computerintegratedmanufacturingisthetermusedtodescribethemodernapproachtomanufacturing.Managementistheprocessofmakingdirectingtheactivitiesofpersonneltoachievestatedobjectives.AnAGVisacomputer-controlled,driverlessvehicleusedfortransportingmaterialsformpointinamanufacturingsetting.InanydiscussionofAGVs,threekeytermsarefrequentlyused:1:Guidepath.2:Routing.3:Trafficmanagement.Unit19Partacquisitiontimeishighlydependentonthenatureofthelayoutoftheassenmblyareaandthemethodofassembly.Assemblyinthemanufacturingprocessconsistsofputtingtogetherallthecomponentpartsandsub-assembliesofagivenproduct,fastening,performinginspectionsandfunctionaltests,labeling,separatinggoodassembliesfrombad,andpackagingandorpreparingthemforfinaluse.Unit20XXutomationisawidelyusedterminmanufacturing.FixedautomationiswhatHarderwasreferringtowhenhecoinedthewordautomation.Numericalcontrolcanbedefinedasaformofprogrammableautomationinwhichtheprossiscontrolledbynumbers,letters,andsymbols.Theprogramofinstructionsisthedetailedstep-by-stepsetofdirectionswhichtellthemachinetoolwhattodo.Thehighestdegreeofautomationobtainablewithspecial-purpose,multifunctionmachinesisachievedbyusingtransfermachines.第三篇：机械专业英语文章中英文对照英语原文NUMERICALCONTROLNumericalcontrol(N/C)isaformofprogrammableautomationinwhichtheprocessingequipmentiscontrolledbymeansofnumbers,letters,andothersymbols,Thenumbers,letters,andsymbolsarecodedinanappropriateformattodefineaprogramofinstructionsforaparticularworkpartorjob.Whenthejobchanges,theprogramofinstructionsischanged.ThecapabilitytochangetheprogramiswhatmakesN/Csuitableforlow-andmedium-volumeproduction.Itismucheasiertowriteprogramsthantomakemajoralterationsoftheprocessingequipment.Therearetwobasictypesofnumericallycontrolledmachinetools：point—to—pointandcontinuous—path(alsocalledcontouring).Point—to—pointmachinesuseunsynchronizedmotors,withtheresultthatthepositionofthemachiningheadCanbeassuredonlyuponcompletionofamovement,orwhileonlyonemotorisrunning.Machinesofthistypeareprincipallyusedforstraight—linecutsorfordrillingorboring.TheN/Csystemconsistsofthefollowingcomponents：datainput,thetapereaderwiththecontrolunit,feedbackdevices,andthemetal—cuttingmachinetoolorothertypeofN/Cequipment.Datainput,alsocalled“man—to—controllink”,maybeprovidedtothemachinetoolmanually,orentirelybyautomaticmeans.Manualmethodswhenusedasthesolesourceofinputdataarerestrictedtoarelativelysmallnumberofinputs.Examplesofmanuallyoperateddevicesarekeyboarddials,pushbuttons,switches,orthumbwheelselectors.Thesearelocatedonaconsolenearthemachine.Dialsaleanalogdevicesusuallyconnectedtoasyn-chro-typeresolverorpotentiometer.Inmostcases,pushbuttons,switches,andothersimilartypesofselectorsaredigitalinputdevices.Manualinputrequiresthattheoperatorsetthecontrolsforeachoperation.Itisaslowandtediousprocessandisseldomjustifiedexceptinelementarymachiningapplicationsorinspecialcases.Inpracticallyallcases,informationisautomaticallysuppliedtothecontrolunitandthemachinetoolbycards,punchedtapes,orbymagnetictape.Eight—channelpunchedpapertapeisthemostcommonlyusedformofdatainputforconventionalN/Csystems.Thecodedinstructionsonthetapeconsistofsectionsofpunchedholescalledblocks.Eachblockrepresentsamachinefunction,amachiningoperation,oracombinationofthetwo.TheentireN/Cprogramonatapeismadeupofanaccumulationofthesesuccessivedatablocks.Programsresultinginlongtapesallwoundonreelslikemotion-picturefilm.Programsonrelativelyshorttapesmaybecontinuouslyrepeatedbyjoiningthetwoendsofthetapetoformaloop.Onceinstalled,thetapeisusedagainandagainwithoutfurtherhandling.Inthiscase,theoperatorsimplyloadsand1unloadstheparts.Punchedtapesalepreparedontypewriterswithspecialtape—punchingattachmentsorintapepunchingunitsconnecteddirectlytoacomputersystem.Tapeproductionisrarelyerror-free.Errorsmaybeinitiallycausedbythepartprogrammer,incardpunchingorcompilation,orasaresultofphysicaldamagetothetapeduringhandling,etc.Severaltrialrunsareoftennecessarytoremoveallerrorsandproduceanacceptableworkingtape.Whilethedataonthetapeisfedautomatically,theactualprogrammingstepsaledonemanually.Beforethecodedtapemaybeprepared,theprogrammer,oftenworkingwithaplanneroraprocessengineer,mustselecttheappropriateN/Cmachinetool,determinethekindofmaterialtobemachined,calculatethespeedsandfeeds,anddecideuponthetypeoftoolingneeded.Thedimensionsonthepartprintarecloselyexaminedtodetermineasuitablezeroreferencepointfromwhichtostarttheprogram.Aprogrammanuscriptisthenwrittenwhichgivescodednumericalinstructionsdescribingthesequenceofoperationsthatthemachinetoolisrequiredtofollowtocuttheparttothedrawingspecifications.Thecontrolunitreceivesandstoresallcodeddatauntilacompleteblockofinformationhasbeenaccumulated.Ittheninterpretsthecodedinstructionanddirectsthemachinetoolthroughtherequiredmotions.Thefunctionofthecontrolunitmaybebetterunderstoodbycomparingittotheactionofadialtelephone,where,aseachdigitisdialed,itisstored.Whentheentirenumberhasbeendialed,theequipmentbecomesactivatedandthecalliscompleted.Siliconphotodiodes,locatedinthetapereaderheadonthecontrolunit,detectlightasitpassesthroughtheholesinthemovingtape.Thelightbeamsareconvertedtoelectricalenergy,whichisamplifiedtofurtherstrengthenthesignal.Thesignalsarethensenttoregistersinthecontrolunit,whereactuationsignalsarerelayedtothemachinetooldrives.Somephotoelectricdevicesarecapableofreadingatratesupto1000characterspersecond.Highreadingratesarenecessarytomaintaincontinuousmachine—toolmotion；otherwisedwellmarksmaybegeneratedbythecutteronthepartduringcontouringoperations.Thereadingdevicemustbecapableofreadingdatablocksataratefasterthanthecontrolsystemcanprocessthedata.AfeedbackdeviceisasafeguardusedonsomeN/Cinstallationstoconstantlycompensateforerrorsbetweenthecommandedpositionandtheactuallocationofthemovingslidesofthemachinetool.AnN/Cmachineequippedwiththiskindofadirectfeedbackcheckingdevicehaswhatisknownasaclosed-loopsystem.Positioningcontrolisaccomplishedbyasensorwhich,duringtheactualoperation,recordsthepositionoftheslidesandrelaysthisinformationbacktothecontrolunit.Signalsthusreceivedalecomparedtoinputsignalsonthetape,andanydiscrepancybetweenthemisautomaticallyrectified.Inanalternativesystem,calledanopen—loopsystem,themachineispositionedsolelybysteppingmotordrivesinresponsetocommandsbyacontrollers.ThereisonebasictypeofNCmotions.Point-to-pointorPositionalControlInpoint-to-pointcontrolthemachinetoolelements(tools,table,etc.)aremovedtoprogrammedlocationsandthemachiningoperationsperformedafterthemotionsarecompleted.Thepathorspeedofmovementbetweenlocationsisunimportant;onlythecoordinatesoftheendpointsofthemotionsareaccuratelycontrolled.Thistypeofcontrolissuitablefordrillpressesandsomeboringmachines,wheredrilling,tapping,orboringoperationsmustbeperformedatvariouslocationsontheworkpiece.Straight-LineorLinearControlStraight-Linecontrolsystemsareabletomovethecuttingtoolparalleltooneofthemajoraxesofthemachinetoolatacontrolledratesuitableformachining.Itisnormallyonlypossibletomoveinonedirectionatatime,soangularcutsontheworkpiecearenotpossible,consequently,formillingmachines,onlyrectangularconfigurationscanbemachinedorforlathesonlysurfacesparallelorperpendiculartothespindleaxiscanbemachined.Thistypeofcontrolledmotionisoftenreferredtoaslinearcontrolorahalf-axisofcontrol.Machineswiththisformofcontrolarealsocapableofpoint-to-pointcontrol.TheoriginalN/Cusedtheclosed—loopsystem.Ofthetwosystems,closedandopenloop,closedloopismoreaccurateand,asaconsequence,isgenerallymoreexpensive.Initially,open—loopsystemswereusedalmostentirelyforlight-dutyapplicationsbecauseofinherentpowerlimitationspreviouslyassociatedwithconventionalelectricsteppingmotors.Recentadvancesinthedevelopmentofelectrohydraulicsteppingmotorshaveledtoincreasinglyheaviermachineloadapplications.中文译文数控技术数控是可编程自动化技术的一种形式,通过数字、字母和其他符号来控制加工设备。数字、字母和符号用适当的格式编码为一个特定工件定义指令程序。当工件改变时,指令程序就改变。这种改变程序的能力使数控适合于中、小批量生产,写一段新程序远比对加工设备做大的改动容易得多。数控机床有两种基本形式：点位控制和连续控制(也称为轮廓控制)。点位控制机床采用异步电动机,因此,主轴的定位只能通过完成一个运动或一个电动机的转动来实现。这种机床主要用于直线切削或钻孔、镗孔等场合。数控系统由下列组件组成：数据输入装置,带控制单元的磁带阅读机,反馈装置和切削机床或其他形式的数控设备。数据输人装置,也称“人机联系装置”,可用人工或全自动方法向机床提供数据。人工方法作为输人数据唯一方法时,只限于少量输入。人工输入装置有键盘,拨号盘,按钮,开关或拨轮选择开关,这些都位于机床附近的一个控制台上。拨号盘通常连到一个同步解析器或电位计的模拟装置上。在大多数情况下,按钮、开关和其他类似的旋钮是数据输入元件。人工输入需要操作者控制每个操作,这是一个既慢又单调的过程,除了简单加工场合或特殊情况,已很少使用。几乎所有情况下,信息都是通过卡片、穿孔纸带或磁带自动提供给控制单元。在传统的数控系统中,八信道穿孔纸带是最常用的数据输入形式,纸带上的编码指令由一系列称为程序块的穿孔组成。每一个程序块代表一种加工功能、一种操作或两者的组合。纸带上的整个数控程序由这些连续数据单元连接而成。带有程序的长带子像电影胶片一样绕在盘子上,相对较短的带子上的程序可通过将纸带两端连接形成一个循环而连续不断地重复使用。带子一旦安装好,就可反复使用而无需进一步处理。此时,操作者只是简单地上、下工件。穿孔纸带是在带有特制穿孔附件的打字机或直接连到计算机上的纸带穿孔装置上做成的。纸带制造很少不出错,错误可能由编程、卡片穿孔或编码、纸带穿孔时的物理损害等形成。通常,必须要试走几次来排除错误,才能得到一个可用的工作纸带。虽然纸带上的数据是自动进给的,但实际编程却是手工完成的,在编码纸带做好前,编程者经常要和一个计划人员或工艺工程师一起工作,选择合适的数控机床,决定加工材料,计算切削速度和进给速度,决定所需刀具类型,仔细阅读零件图上尺寸,定下合适的程序开始的零参考点,然后写出程序清单,其上记载有描述加工顺序的编码数控指令,机床按顺序加工工件到图样要求。控制单元接受和储存编码数据,直至形成一个完整的信息程序块,然后解释数控指令,并引导机床得到所需运动。为更好理解控制单元的作用,可将它与拨号电话进行比较,即每拨一个数字,就储存一个,当整个数字拨好后,电话就被激活,也就完成了呼叫。装在控制单元里的纸带阅读机,通过其内的硅光二极管,检测到穿过移动纸带上的孔漏过的光线,将光束转变成电能,并通过放大来进一步加强信号,然后将信号送到控制单元里的寄存器,由它将动作信号传到机床驱动装置。有些光电装置能以高达每秒1000个字节的速度阅读,这对保持机床连续动作是必须的,否则,在轮廓加工时,刀具可能在工件上产生划痕。阅读装置必须要能以比控制系统处理数据更快的速度来阅读数据程序块。反馈装置是用在一些数控设备上的安全装置,它可连续补偿控制位置与机床运动滑台的实际位置之间的误差。装有这种直接反馈检查装置的数控机床有一个闭环系统装置。位置控制通过传感器实现,在实际工作时,记录下滑台的位置,并将这些信息送回控制单元。接受到的信号与纸带输入的信号相比较,它们之间的任何偏差都可得到纠正。在另一个称为开环的系统中,机床仅由响应控制器命令的步进电动机驱动定位,工件的精度几乎完全取决于丝杠的精度和机床结构的刚度。有几个理由可以说明步进电机是一个自动化申请的非常有用的驱动装置。对于一件事物,它被不连续直流电压脉冲驱使,是来自数传计算机和其他的自动化的非常方便的输出控制系统。当多数是索引或其他的自动化申请所必备者的时候,步进电机对运行一个精确的有角进步也是理想的。因为控制系统不需要监听就提供特定的输出指令而且期待系统适当地反应的公开-环操作造成一个回应环,步进电机是理想的。一些工业的机械手使用高抬腿运步的马乘汽车驾驶员,而且步进电机是有用的在数字受约束的工作母机中。这些申请的大部分是公开-环,但是雇用回应环检测受到驱策的成份位置是可能的。环的一个分析者把真实的位置与需要的位置作比较,而且不同是考虑过的错误。那然后驾驶员能发行对步进电机的电脉冲,直到错误被减少对准零位。在这个系统中,没有信息反馈到控制单元的自矫正过程。出现误动作时,控制单元继续发出电脉冲。比如,一台数控铣床的工作台突然过载,阻力矩超过电机转矩时,将没有响应信号送回到控制器。因为,步进电机对载荷变化不敏感,所以许多数控系统设计允许电机停转。然而,尽管有可能损坏机床结构或机械传动系统,也有使用带有特高转矩步进电机的其他系统,此时,电动机有足够能力来应付系统中任何偶然事故。最初的数控系统采用开环系统。在开、闭环两种系统中,闭环更精确,一般说来更昂贵。起初,因为原先传统的步进电动机的功率限制,开环系统几乎全部用于轻加工场合,最近出现的电液步进电动机已越来越多地用于较重的加工领域。第四篇：机械专业英语复试词汇总结（推荐）机械英语词汇大全2金属切削metalcutting机床machinetool拉孔broaching装配assembling数学模型mathematicalmodel画法几何descriptivegeometry金属工艺学technologyofmetals刀具cutter摩擦friction联结link传动drive/transmission轴shaft弹性elasticity频率特性frequencycharacteristic误差error响应response定位allocation机床夹具jig动力学dynamic运动学kinematic静力学static分析力学analysemechanics拉伸pulling压缩hitting剪切shear铸造found流体动力学fluiddynamics机械制图Mechanicaldrawing流体力学fluidmechanics投影projection加工machining视图view液压hydraulicpressure剖视图profilechart切线tangent标准件standard机电一体化mechanotronicscomponentmechanical-electricalintegration零件图partdrawing气压airpressurepneumaticpressure装配图assemblydrawing稳定性stability尺寸标注sizemarking介质medium技术要求technical液压驱动泵fluidclutchrequirements液压泵hydraulicpump刚度rigidity阀门valve内力internalforce失效invalidation位移displacement强度intensity截面section载荷load疲劳极限fatiguelimit应力stress断裂fracture安全系数saftyfactor塑性变形plasticdistortion扭转twist弯曲应力bendingstress强度intensity三相交流电three-phaseAC磁路magneticcircles变压器transformer异步电动机asynchronousmotor几何形状geometrical精度precision正弦形的sinusoid交流电路ACcircuit机械加工余量machiningallowance变形力deformingforce变形deformation应力stress硬度rigidity热处理heattreatment退火anneal正火normalizing脱碳decarburization渗碳carburization电路circuit半导体元件semiconductor可靠性reliability螺纹thread螺旋helix键spline销pin滚动轴承rollingbearing滑动轴承slidingbearing弹簧spring制动器arresterbrake十字结联轴节crosshead联轴器coupling链chain皮带strap精加工finishmachining粗加工roughmachining变速箱体gearboxcasing腐蚀rust氧化oxidation磨损wear耐用度durability随机信号randomsignal离散信号discretesignal超声传感器ultrasonicsensor脆性材料brittlenessmaterial刚度准则rigiditycriterion垫圈washer垫片spacer直齿圆柱齿轮straighttoothedspurgear斜齿圆柱齿轮helical-spurgear直齿锥齿轮straightbevelgear运动简图kinematicsketch齿轮齿条pinionandrack蜗杆蜗轮wormandwormgear虚约束passiveconstraint曲柄crank摇杆racker凸轮cams共轭曲线conjugatecurve范成法generationmethod定义域definitionaldomainelement反馈feedback发生器generator直流电源DCelectricalsource门电路gatecircuit逻辑代数logicalgebra外圆磨削externalgrinding内圆磨削internalgrinding平面磨削planegrinding变速箱gearbox离合器clutch绞孔fraising绞刀reamer螺纹加工threadprocessing螺钉screw铣削mill铣刀millingcutter功率power工件workpiece齿轮加工gearmechining齿轮gear主运动mainmovement主运动方向directionofmain集成电路integratecircuit挡板orificeplate残余应力residualstress套筒sleeve扭力torsion冷加工coldmachining电动机electromotor汽缸cylinder过盈配合interferencefit热加工hotwork摄像头CCDcamera倒角roundingchamfer优化设计optimaldesign工业造型设计industrialmouldingdesign有限元finiteelement滚齿hobbing插齿gearshaping伺服电机actuatingmotor铣床millingmachine钻床drillmachine镗床boringmachine步进电机steppermotor值域range导数微分differentialcoefficient求导derivation定积分definiteintegral不定积分indefiniteintegral曲率curvature偏微分p