电梯结构及原理教案曳引式电梯

电梯构造及原理教案-1曳引式电梯Tractionlift电梯是一种机电结合严密地用电力拖动的特别升降设备，是一种现代生活中必不可少的，广泛应用的垂直交通运输工具，在现代城市文明中，电梯不但已成为高层建筑不行缺少的垂直运输设备，也将成为低层建筑中的代步工具。在垂直交通运输工具中曳引式电梯是使用最普遍的一种电梯。因此，本文以介绍曳引式电梯为主。Beingaspecialsystemmovingupwardsanddownwardsbycombiningmechanicsandelectrics,lifthasplayedanindispensableroleinourmodernlifebyservingaswidely-usedvehiclethatrunsvertically;itisnotonlyanimportantverticalvehicleforhigh-risebuildings,butforlow-risingbuildings.Asaverticalvehicle,tractionliftisthemostcommonlyusedlift;therefore,thefollowingdescriptionwillbebasedontractionlift.电梯的根本构造Liftbasicstructure1-1-1曳引系统Tractionsystem曳引系统主要由曳引机、曳引钢丝绳、导向轮及反绳轮等组成。Tractionsystemiscomposedoftractionmachine,tractionrope,diverterpulleyandcounterweightsheave.曳引机有驱动电动机、制动器、减速箱、机座、曳引轮等组成。它是电梯的动力源。驱动电动机为电梯专用沟通电机或直流电机。Asthepowerprovider,tractionmachineiscomposedofdrivemotor,brake,gearedmachine,machinebaseandtractionsheave.DrivemotorisACorDCmotorforlift.闸，以保证电梯不致移动。Usuallyadoptedisdoublelinednormallyclosedmagneticbrake.Brakeisactivatedtopreventliftfrommovingincaseofliftstoporpowerfailure.机。无齿轮电梯不需减速机。1Usuallyadoptediswormgearedmachine,besides,stargearandslantinggearedmachinearealsoavailable.Gearlessliftneedsnogearedmachine.Tractionsheaveisasheaveontractionmachine,onbothsidesofwhichcansuspendcarandcounterweightbymeansoftractionrope.曳引钢丝绳的两端分别连接轿厢和对重(或两端固定在机房上)，依靠钢丝绳与曳引轮绳槽之间的静摩擦力来实现电梯轿厢的升降。Bothsidesofthetractionropeareconnectedwithcarandcounterweight(orbothsidesareattachedtothemachineroom).Carismovedupwardsordownwardsbymeansofstaticfrictionbetweentraction1-1-1-3大，轿厢悬挂中心和对重悬挂中心间的距离往往大于设计上所允许的曳引轮直径，因此对一般电梯而言需要设置导向轮，以保证两股向下的曳引钢丝绳之间的距离等于或接近轿厢悬挂中心和对重悬挂中心之间的距离，以分开轿厢和对重的间距。DeflectorsheaveisalsocalledbeamPulley.Sincecariscomparativelylargeindimensions;thedistancebetweencarsuspensioncenterandcounterweightsuspensioncenterisgenerallylongerthanthediameteroftractionsheave,deflectorsheaveisusuallyusedforliftstoensurethedistancebetweentworopesdownwardstobeequaloralmostequaltothedistancebetweencarsuspensioncenterandcounterweightsuspensioncenter,distancingcarandcounterweight.对复绕的无齿轮电梯而言，转变复绕轮的位置同样可以到达上述目的。承受复绕轮还可以增加曳引力量。Forgearlessliftwithcompoundwounding,changingthepositionofwindingpulleycanalsoachievetheabovepurpose,besidestheapplicationofcompoundwindingpulleycanalsoincreasetraction1增设反绳轮。反绳轮的个数与曳引比有关，可以是1个、2个甚至是3个。Diversionsheave:withsuspensionratio>1,diversionsheaveshouldbeinstalledonthetopofcarandcounterweightframe.Relatedtosuspensionratio,numberofdiversionsheavecanbe1,2oreven3.导向系统Divertersystem1-4)等组成。它的作用是限制2轿厢和对重的活动自由度，使轿厢和对重只能沿着导轨做升降运动。Composedofguiderails,guideshoesandrailframe,divertersystemisusedtolimittheflexibilityofcarandcounterweight,makingcarandcounterweightmovealongtheguiderailupwardsanddownwards.导轨固定在导轨架上，导轨架是支撑导轨的组件，与井道壁联接。Guiderailsarefixedontherailframethatisusedtosupportrailsandconnectedwithwellwall.导靴装在轿厢和对重架上，与导轨协作，强制轿厢和对重的运动听从于导轨的走向。Installedoncarandcounterweightframe,guideshoesareworkingtogetherwithguiderails,forcingcarandcounterweighttomoveincompliancewiththedirectionofguiderails.Doorsystem门系统由轿厢门、层门、门机、联动机构、门锁等组成。Doorsystemiscomposedofcardoor,leveldoor,dooroperator,interconnectionanddoorlock.轿厢门设在轿厢入口，有门扇、门导轨架、门靴和门刀等组成。Locatedintheentrancetocar,cardooriscomposedofdoorfan,doorguiderailframe,doorshoeanddoorvane.成。Locatedintheentrancetolanding,landingdooriscomposedofdoorfan,doorguiderailframe,doorshoe,doorlockandemergencyunlockingdevice.Installedonthecar,dooroperatorispowerproviderforopeningandclosingcardoorandlandingdoor.轿厢Car轿厢是用以运送乘客或货物的电梯组件。它是由轿厢架和轿厢体组成。Composedofcarframeandcarbody,carisusedtoconveypassengersorcargo.轿厢架是轿厢体的承重架构，由上横梁、立柱、底梁和斜拉杆等组成。Asasupportforcarbody,carframeiscomposedoftoptransom,sidetransom,3bottomtransomandbracerod.轿厢体由轿厢底、轿厢壁、轿厢顶及照明、通风装置、轿厢装饰件和操纵盘等组成。轿厢的大小由额定载重量和额定载客量打算。Carboyiscomposedofcarbottom,carwall,cartop,ventilation,decorationprofileandcontrolpanel.Cardimensionsaredeterminedbyratedloadandpassengerflow.重量平衡系统Weightbalancesystem该系统由对重和重量补偿装置组成。Suchsystemiscomposedofcounterweightandweightcompensationdevice.Counterweightiscomposedofcounterweightandcounterweightfiller.Counterweightisusedtooffsetcarweightandpartialratedload.重量补偿装置是补偿高层电梯中轿厢与对重侧曳引钢丝绳长度变化对电梯平衡影响的装置。Weightcompensationdeviceisusedtooffsettheinfluenceontheliftbalancearisingfromthechangingropelengthofcarandcounterweight.-1-6电力拖动系统1Electricaldrivingsystem该系统由曳引电机、供电系统、速度反响装置、调速装置等组成。对电梯实行速度掌握。Composedoftractionmachine,powersupplysystem,speedfeedbackdeviceandspeed-adjustingdevice,suchsystemisusedtocontrolliftspeed.Tractionmachineisthepowerproviderforlift.ACorDCmotorcanbeselectedbasedonliftconfiguration.供电系统是为电机供给电源的装置。Powersupplysystemprovidespowerformotor.速度反响装置是为调速系统供给电梯运行速度信号。一般承受测速发电机或速度脉冲发生器，与电机相连。Speedfeedbackdeviceisusedtoprovideliftspeedsignalforspeed-adjustingsystem.Connectedwithmotor,tachogeneratororspeedpulsegeneratorisusuallyadopted.4调速装置对曳引电机实行调速掌握。Speedadjustingdeviceisusedtocontrolspeedoftractionmotor.1-1-7电气掌握系统Electricalcontrolsystem成。它的作用是对电梯的运行实行操纵和掌握。Composedofoperationdevice,positionindicatordevice,controldevice,levelingdeviceandselector,electricalcontrolsystemisusedtooperateandcontrollift.操纵装置包括轿厢操纵盘或手柄开关箱、层站呼唤按钮、轿顶和机房中的检修或应急操纵箱。的集中组件。Operationdeviceiscomposedofoperationpanelorhandleswitchtank,landingcallbutton,inspectionoremergencycontrolbox.Installedinthemachineroom,astheintegratedunitforelectricalcontrol,controldeviceiscomposedofelectricalcontrolcomponents(orpanels).息。Positionindicatorisinstalledincarandlanding,indicatingsuchinformationasliftrunninglanding,directionandpassengerflow.选层器可由机械式、继电器或电子式组成，起指示和反响轿厢位置、打算运行方向、发出减速信号等作用。Havingmechanic,relayorelectronictypes,selectorisusedtoindicateandfeedbackcarposition,determinerunningdirectionandgiveoutreductionsignal.1-1-8安全保护系统Safetyprotectionsystem电梯上设有机械和电气各类保护系统，以保证电梯安全使用。Liftisequippedwithmechanicandelectricalprotectionsystemstoensureliftsafeoperation.机械方面有限速器、安全钳、缓冲器、渐进式行程开关等。Mechanicaldevicesincludeoverspeedgovernor,safetygear,bufferand5progressivetravelswitch.器，轿顶急停开关，底坑急停开关，极限开关，紧急出口接点，超速保护开关，安全钳开关，门保护开关，检修开关等。Electricaldevicesincludeaseriesofsafetyswitchestoprotecteveryoperationstages,suchaspowercut-offprotector,emergencystopswitchontopofthecarandinthepit,limitswitch,emergencyexitcontact,overspeedprotectionswitch,safetygearswitch,doorprotectionswitchandinspectionswitch.1-2电梯的分类Lifttypeso15两列刚性导轨之间运送乘客或货物的固定设备。目前不管其驱动方式如何，将电梯作为建筑物内垂直交通运输工具的总称。Liftisdefinedasafixeddevicethathoistsacartravelingverticallyornotexceeding15?verticallybetweentworigidrails,toconveypassengersorcargo.Whateverdrivetypelifthas,itisacollectivetermforvehicletravelingwithinabuilding.目前电梯的根本分类方法大致如下:Basedonthebuilding’sheight,applicationandpassengerflow(orcargoflow),differenttypesofliftsareused.Currently,liftsareclassifiedbasedonthefollowingcriteria:1-2-1按驱动方式分类Classifiedbydrivetype1-2-1-1沟通电梯AClift用沟通感应电动机作为驱动力的电梯。依据拖动方式又可分为沟通单速、沟通双速、沟通调压调速、沟通调频调压调速电梯。ACmotorisusedinlift.Basedontractiontypes,liftscanbeclassifiedasACsingle-speed,ACdouble-speed,ACspeed/voltage-viable,ACviablespeed/frequencylifts.直流电梯6DClift2m/sDCmotorisusedinliftwhoseratedspeedisabove2m/s.Hydrauliclift利用电动泵驱动液体流淌，由柱塞使轿厢升降的电梯。Bymeansofelectricalpumpdrivingfluid,liftismovedupwardsordownwardsthroughplunders.Gearracklift将导轨加工成齿条，轿厢装上与齿条啮合的齿轮,电动机带动齿轮旋转使轿厢升降的电梯。Railsaremadeintogearracks.Carisequippedwithgearsthatareengagedwithracks.Liftismovedupwardsordownwardsbymeansoftherotationofgearsdrivenbymotor.Spiralleverlift升或下降的电梯。Inspirallevellifts,plundersofstraightly-pushedliftsaremadeintorectangularthreads;bignutswithpushingbearingsareinstalledonthetopofthecylinder.Throughmotor,thebignutsrotatewithgearedmachine(orbelt).Therefore,supportedbythespirallever,liftscanmoveupwardordownwards.1-2-1-6Machinedrivenbylinealmotor其动力源是直线电机。Liftispoweredbylinealmotor.1-2-2按用途分类Classifiedbyapplications1-2-2-1乘客电梯Passengerlift7为运送乘客设计的电梯，要求有完善的安全设施及肯定的轿厢内装饰。Passengerliftisdesignedtoconveypassengersandrequiredtohaveperfectsafetyfacilitiesandnecessarydecorationinthecar.Cargolift无司机载货电梯仅允许装卸人员在装卸货物时出入轿厢，但不允许随货物一同上下，更不准运载乘客。Cargoliftisdesignedtoconveycargoandclassifiedinto2types:Liftwithdriver:driverandservicemenareallowedtobewiththecargointhemovingcar.Liftwithoutdriver:onlyservicemenareallowedtoenterthecartoloadorunloadcargoatthelanding,butnotallowedtobewiththecargoinamovingcar;passengersarenotallowedtoenterthecareither.病床电梯(医用梯)Hospitallift(medicallift)为运送病床、担架、医用车而设计的电梯，轿厢具有长而窄的特点。Characteristicofbeinglongandnarrow,itisdesignedtoconveypatientbed,stretcher,andmedicalvane.效劳电梯(杂物梯)Servicelift(dumbwaiterlift)供图书馆、办公楼、饭店、食品等设计的电梯。这类电梯无安全设施，轿厢内严禁载人。Serviceliftisdesignedforlibrary,officebuildingandhotel.Withoutsafetyfacilities,suchliftisnotallowedtoconveypassengers.Sightseeinglift轿厢壁透亮，供乘客观光用的电梯。Withtransparentcarwall,sightseeingliftisdesignedfortourists.Vehiclelift用作装运车辆的电梯。Vehicleliftisdesignedtoconveyvehicles.8Shiplift船舶上使用的电梯。Shipliftisdesignedforship.1-2-2-8建筑施工电梯Constructionlift建筑施工与修理用的电梯。Constructionliftisdesignedforconstructionandmaintenance.1-2-2-9Others梯、电站电梯、消防员用的电梯等。Besidestheabovementionedlifts,thereareliftsforspecialapplications,suchasfreezerlift,explosion-prooflift,minelift,powerstationliftandfiremanlift.1-2-3按速度分类Classifiedbyspeed电梯无严格的速度分类，一般习惯上如下分类Liftsfallintothefollowingcategories:1.0m/sLow-speedliftisdefinedasliftwithspeedlessthan1.0m/s.1-2-3-21.0,2.0m/sFast-speedliftisdefinedasliftwithspeedrangingfrom1.0m/sto2.0m/s.1-2-3-32.0m/sHigh-speedliftisdefinedasliftwithspeedmorethan2.0m/s.1-2-4Classifiedbyliftwithorwithoutdriver1-2-4-1有司机电梯Liftwithattendant电梯的运行方式由专职司机操纵来完成。Liftrunningisoperatedbyanattendant.1-2-4-2无司机电梯Liftwithoutattendant乘客进入电梯轿厢，按下操纵箱上所需要去的层楼按钮，电梯自动运行到达目的9层楼。这类电梯具有集选功能。Liftwithoutattendant:Enteringthecarandoperatingfloorbuttontoselectafloordesired,passengercanbeconveyedtoalandingdesired.Suchliftisfeaturedcollective-selection.1-2-4-3有/无司机电梯Liftwith/withoutattendant这类电梯可变换掌握电路，寻常由乘客操纵，如遇客流量大或必要时改由司机操作。Liftwith/withoutattendantisoperatedbypassengersusually.Incasedofbigpassengerflowornecessarycircumstance,itwillbeoperatedbytheattendant.按操纵掌握方式分类Classifiedbycontrolmode1-2-5-1手柄开关操纵Handle-operated层、停顿的运行状态。它要求轿厢门上装有透亮玻璃窗口或使用栅栏轿门，井道壁上Byoperatingthehandleofthecontrolboxinthecar,thedrivercanmaketheliftstartup,moveupwards,movedownwards,levelandstop.Itisrequiredthecardoorequippedwithtransparentglasswindoworgridcardoor;wellwallisrequiredtobehavefloororlevelingflag,bywhichthedrivercandeterminefloornumberandcontrolleveling.Button-controlled是一种简洁的自动掌握电梯，据有自动平层功能，常见以下两种掌握方式:Withautomaticlevelingfunction,button-controlledliftissimpleandautomatic,whichhas2controlmodes:Buttonoutsidecar轿厢由安装在各楼层门口的按钮箱进展操纵。操纵内容通常为呼唤电梯、指令运行方向和停靠楼层。电梯在承受了某一层楼的操纵指令，在没有完成指令前是不10Cariscontrolledbythebuttonboxequippedinlandingdoor.Carcall,runningdirectionandparkingcanbecontrolled.Liftwillnotexecuteanynewcommandfromotherlandingsuntilitfinishesexecutingapreviouscommand.Suchcontrolmodeisusuallyapplicabletoserviceliftorcargoliftwithnotmorethan10landings.按钮指令，层站的呼唤按钮只燃亮轿内指示灯(或起动电铃)，不能截停和操纵电梯。Buttoninsidecar:buttonsinsidecarareoperatedbythedriver.Liftonlyacceptscommandinsidecar;landingcallbuttoncanonlylightupindicatorsinsidecar(orstartalarm),cannotstoporoperatelift.信号掌握电梯Signal-controlledlift外，能。司机只要将需要停站的层楼按钮逐一按下，再按下启动按钮，电梯就自动关门运毕。在运行中，电梯能被符合运行方向的层站呼唤信号截停。承受这种掌握方式的常为有司机客梯。Itisahighlyautomatedliftwithdriver.Besideshavingautomaticlevelinganddoor-opening,ithassuchfunctionsascommandregister,landingcallregister,automaticlanding,on-the-waystopandautomaticreturn.Justpressingthedesiredfloorbuttonsonebyoneandstart-upbutton,thedrivercanmaketheliftclosethedoorandoperate.集选掌握电梯Collectiveselectivecontrollift是一种在信号掌握根底上进展起来的全自动掌握的电梯。与信号掌握的主要区别在于能实现无司机操纵。其主要特点是:把轿厢内选层信号和各层外呼信号集合置，以免电梯超载。轿门上需设有保护装置，防止乘客出入轿厢时被轧伤。Evolvingfromsignalcontrollift,collectiveselectivecontrolliftisfullyautomatic.Comparedwiththeformer,itcanachievedriverlesscontrol.Itsmaincharacteristicisthecombinationofcarcallandlandingcall,soasto11automaticallycontrolupwardanddownwardmovement,andsequentresponse.Load-weightdeviceshouldbeinstalledinthecartoavoidoverload.Alsoprotectiondeviceisneededonthecardoortoprotectpassengersagainstbodyinjuryduringgettinginandoutfromthecar.集选掌握又分为全集选(双向)掌握和上或下(单向)集选掌握。全集选掌握的答内。Collectiveselectivecontrolisclassifiedintowhole(two-way)andupwardordownward(one-way)collectiveselectivecontrol.Inthemodeofwholecollectiveselectivecontrol,liftwillrespondtoalllandingcallsnomatterinupwardordownwardmovement.Inthemodeofone-waycollectiveselectivecontrol,liftwillonlyrespondtolandingcallfromupwardordownward.Generallyspeaking,collectiveselectivecontroldownwardisusedmorefrequently,forinstance,forresidentialbuilding.并联掌握电梯Parallelcontrollift2身都具有集选功能。PLCisexecutedthroughparallelcircuitforthecontroloftwotothreelifts,withlandingcallbuttonshared.Lifthascollectiveselectivefunction.台电梯执行指令完毕后，自动返回基站。另一台电梯在完成其全部任务后，就停留在最终停靠的层楼作为备用梯，预备承受基站以上消灭的任何指令而运行。基站梯可优先供进入大楼的乘客效劳，备用梯主要应答其他层楼的呼唤。当重消灭呼唤指令时，备用梯首先应答、启动、运行。当备用梯运行前方消灭呼唤信号时，则基站梯承受信定。备用梯也有可能在执行轿厢内乘客的指令后停留在基站，优先应答基站呼唤。Fortwoliftswithparallelcollectiveselectivecontrol,sincehomelandingisonthebottomofthebuilding,afteronelifthasexecutedcommand,itwillreturntothehomelandingashomelandinglift.Finishingalltasks,theotherliftwilldwellinthelatestlandingasastand-bylifttowaitforfurthercommandfromlandingsabovethehomelanding.Receivingcallcommand,thestand-bylift12willrespond,startupandrun.Ifanycallgivesoutaftertheoperationofthestand-bylift,thehomelandingliftwillreceivethecallandstart.Homelandingliftandstand-byliftarechangeableaccordingtoactualcircumstances.Stand-byliftcanalsoparkinthehomelandingafterexecutingcommandsfrompassengersinthecar,respondingtohomelandingpreferably.三台并联集选组成的电梯，有两台电梯作为基站梯，一台为备用梯。运行原则类同于两台并联掌握电梯。Forthreeliftswithparallelcollectiveselectivecontrol,twoofthemwillserveashomelandinglifts,withtheremainingoneasstand-bylift.Operationprincipleissameasthatoftwolifts.群控电梯Groupcontrollifts群控是用微机掌握和统一调度多台集中并列的电梯。群控可以有:Groupcontrolliftsareseveralliftscontrolledandcoordinatedbycomputer.1-2-5-6-1中调度和掌握。如将一天中客流分成上行客流量顶峰状态，客流量平衡状态，下行客流量顶峰状态，上行客流量较下行大的状态，下行客流量较上行大的状态，空闲时的客流量状态。电梯在工作中，依据当时客流状况，以轿厢的负载、层站的呼唤频繁程度，运行一周的时间间隔等为依据，自动选择或人工变换掌握程序，如在上行顶峰期，对电梯实行下行直驶掌握等。Programcontrol:Coordinationandcontrolaremadethroughprogrammedtrafficmode.Forinstance,passengerflowinonedayisclassifiedintothefollowingstatuses:upwardpeaktraffic,balancedtraffic,downwardpeaktraffic,upwardtrafficflowmorethandownwardtrafficflow,downwardtrafficflowmorethanupwardtrafficflow,idletraffic.Forliftinservice,basedonpassengerflow,carload,landingcallfrequency,runningintervalforoneweek,itispossibletoselectautomaticormanualcontrolprogram,forinstance,duringupwardpeaktraffic,downwardrunningwithnon-stopispossibleforlift.1-2-5-6-2还有进展分析、筛选、报告的功能。掌握系统可以显示出全部电梯的运行状态，同过专用程序可分析电梯的工作效率、评价电梯的效劳水平。计算机依据当前的客流状况，自动选择最正确的运行掌握程序。最研制出的大楼治理系统，包括了统。13Intelligencecontrolledlift:Ithassuchfunctionsasdatacollection,dataexchange,saving,analysis,screeningandreport.Controlpanelcandisplayoperationstatusofalllifts;lift-specificprogramcananalyzeliftefficiencyandevaluateliftservicequality.Basedoncurrentpassengerflow,computercanselectoptimumoperationcontrolprogram.Thelatestdevelopedbuildingmanagementsystemincludesallservicefacilities,suchasboiler,heatingsystem,air-conditioningsystem,groupcontrolandmanagementintelligencesystem.按曳引机有无减速机分类Classifiedbytractionmachinewithorwithoutgearedmachine1-2-6-1般电梯的额定速度?2m/s。tractionmachinewithgearedmachine:Thespeedoftractionmachineisnotequaltothatofmotor(thespeedofmotorismorethanthatoftractionmachine.).Thereawormgearedmachineorgearlessmachine(stargear,slantinggear).Normallyratedspeedofliftis?2m/s.1-2-6-2无齿轮电梯电梯曳引轮转速与电动机转速相等，中间无涡轮蜗杆减速机或齿轮减速机。对于此类电梯，要求电动机具有低转速、大转矩特性。电梯的额定速度?2m/s。Gearlesslift:Thespeedoftractionmachineisequaltothatofmotor.Thereisnowormgearedmachineorgearlessmachine.Forsuchlifts,themotorshouldbeoflowspeed,bigtorque,withratedspeedequaltoormorethan2m/s.按机房位置分类Classifiedbymachineroomposition1-2-7-1Upper-arrangedmachinedroom:machineroomisarrangedonethetopofthewell.下置式机房机房在井道的底部;Lower-arrangedmachineroom:machineroomisarrangedatthebottomofthewell.侧置式机房机房在距离井道50m以内的任何地方;14Side-arrangedmachineroom:machineroomisarrangedanyplacewithin50metersfromthewell.房。Liftwithoutmachineroom:tractionmachineisarrangedonthetopofthecarorguiderailabovethewell;nomachineroomisneeded.Tractiondrive曳引传动定义:此传动系统通过摩擦来带动电梯垂直运行的传动形式。具体地说另一端悬吊对重,曳引轮转动时,由钢丝绳与曳引轮槽之间的摩擦产生曳引力驱动轿厢作1-1。断地上升和下降。Asadrivemode,tractiondrivecanmakeliftmoveverticallybymeansoffriction.Tobespecific,tractionropeissuspendedonthetractionsheave,onesideofwhichissuspendedwithcar,theothersideofwhichissuspendedwithcounterweight.Whentractionsheaveisrotating,thefrictionbetweentractionropeandgroovewillproducetractionforcetomovecarupwardsanddownwards.Seefig1-1Withenoughfrictionbetweentractionropeforsuspendingcarandcounterweightandropegroovetooffsetthedifferentialtensiononthetractionropeofcarandcounterweight,carandcounterweightkeeponmovingupwardsordownwardsbymeansofclockwiseandcounterclockwiserotationoftractionsheave.曳引传动的特点:Characteristicoftractiondrive1-3-2-1Safeandreliable15当轿厢或对重由于某种缘由超过了规定的行程遇到缓冲器时，曳引传动机构能自绳。Incaseofcarorcounterweightrunbytotouchbuffer,tractionmachinewilllosetractioncapacityautomatically,topreventcarorcounterweightfromcollidingwithtoporbottom,orbreakingtractionrope.1-3-2-2Highhoistingtravel曳引式电梯不像卷扬机那样，钢丝绳不断地一圈一圈地绕在卷筒上，其钢丝绳的长度不受限制，因此可以实现将轿厢提升到任何实际需要的高度上。Unlikewindlass,tractionliftcanhaveropeswoundonebyonearoundthecoiler,withunlimitedlength,soastohoistcartoanydesiredheight.1-3-2-3构造简洁Simpleinstructure对于垂直起吊设备，依据标准要求，曳引轮(或卷筒)直径与钢丝绳直径之比不直径，从而到达曳引轮直径的减小和使整个机构的重量减轻。Toverticallyhoistequipment,itisconventionallyrequiredthatthediameterratiooftractionsheave(orcoiler)totractionropebe?40.Fortractionlift,itiseasiertodecreasethediameteroftractionmachineandtotalweightbyincreasingropenumberordecreasingdiameter.1-3-2-4Matchingeconomicalandcompacthigh-speedmotor在电梯额定速度肯定的状况下，曳引轮直径越小，则需要曳引轮转速越高，与此同时也就要求驱动电动机转速越高。因此承受曳引式传动便于选用紧凑、价格便宜的高速电动机。Ifratedspeedisdefinite,thesmallerthediameteroftractionsheaveis,thefasterthespeedofthetractionsheaveandmotorisrequired.Therefore,compactandeconomicalhigh-speedmotorcanbeusedontractiondrive.常见的曳引传动形式Typicaltractiondrivemodes由于曳引机的位置、速度、负载等是不同的，钢丝绳的绕法也就不同，但要尽可Windingmethodfortractionropeisdifferentduetodifferentposition,speed16andload.However,itisrequiredtoadoptsimplewindingandfixedpulleysasfewaspossible,toprolongtractionropelifeandimproveefficiency.1-3-3-1钢丝绳绕绳方式Tractionropewindingmethod0180绳方式称为单绕，或称半绕;曳引绳绕曳引轮和导向轮一周后才被引向轿厢和对重的绕绳方式称为复绕，或称全绕。复绕方式增加了曳引绳在曳引轮上的包角，提高了摩擦力。Tractionropeissuspendedontractionsheaveanddiverterpulley;themaximumangleoftractionropetotractionsheaveshouldbe?180?.Suchwindingmethodisdefinedassinglewindingorhalfwinding.Tractionropewillnotleadtocarandcounterweightuntilitwindstractionsheaveanddiverterpulleyforoneround.Suchwindingiscalledcompoundwindingorfullwinding,whichincreasesangleandfriction.(A)、(B)、(C)1-(D)为复绕方式。Fig.1-2-1:Windingtypesforuppertractionmachine;(A),(B)and(C)aresinglewinding,(D)iscompoundwinding.(A)、(B)、(C)为单绕方式，(D)为复绕方式。Fig.1-2-2:Windingmethodsforlower-placedtractionmachine;(A),(B)and(C)aresinglewinding,(D)iscompoundwinding.1-3-3-2曳引比Tractionratio曳引比是指电梯在运行时曳引钢丝绳的线速度与轿厢升降速度之间的比值。曳引比即为绕绳比。假设曳引绳的速度等于轿厢的升降速度，我们就称曳引比为1?1，即曳引绳从轿1-2-1(A)的构造所示。22?1，1-2-1(B)的构造所示。当曳引比为2?1(如图1-2-1(B)所示)、4?1(如图1-2-1(C)所示)时，轿厢顶和对重上部都要安装动滑轮，每根曳引绳端头都固定在机房上梁上，这样轿厢的速度分别为曳引绳速度的1/2和1/4，作用到曳引绳上的载荷分别为1/2171/4,因而可削减绳直径或绳根数。Tractionratioisdefinedastheratiooflinealspeedoftractionropetothatofcarrunningspeed.Tractionratioiswindingratio.Giventhespeedoftractionropeisequaltothatofmovingcar,wecallit1:1tractionratio,i.e.tractionropeleadsfromcartocounterweight,asshowninfig.1-2-1(A).Giventhespeedoftractionropeistwicethatofamovingcar,wecallit2:1tractionratio,asshowninfig.1-2-1(B).Iftractionratiois2:1or4:1,asshownin1-2-1(B)and1-2-1-1(C),amovablepulleyisrequiredtobeinstalledonthetopofcarandcounterweight;tractionropeheadmustbeattachedtothetopofthemachineroom,therefore,carspeedwillbe1/2and1/4ofthatoftractionrope,andloadontractionropewillbe1/2and1/4,makingareductioninropediameterandnumber.18电梯的曳引力量Tractioncapacity1-3-4-1曳引系数Tractioncoefficient1-3T1和悬挂对重一端的拉力T2之间应满足什么关系呢,依据著名的欧T1T219关系(1-1Tractionforceexertedontheliftisshownasinfig.1-3.Thetractionropeisinabalancedstate,i.e.itisabouttosliponthetractionsheave.What’stherelationbetweenpullingforeT1ononesideofthetractionropeandT2ontheotherside?Inthefollowingequation,wecansee(formula1-1):式中:where:f—曳引绳在曳引轮绳槽中的当量摩擦系数;f—frictioncoefficientoftractionropeintractionsheavegrooveα的包角;α—circularangleincorrespondencewithanarchoverlappedbytractionropeandsheave,i.e.angleoftractionropeintractionsheave—自然常数=2.71828ee—natureconstant=2.71828eefαƒ、αefαfisreferredtoastractioncoefficient,whichisrelatedtoandα.efαfαT1/T2T1/T2(T1-T2)ee的允许值大，也就说明电梯的曳引力量大。fαfαlimitsT1/T2,thelargeris，thelargerT1/T2is，indicatinglargereetractioncapacity.因此，一台电梯的曳引系数代表了该台电梯的曳引力量。曳引系数越大，电梯的载货或载客力量就越大;反之假设曳引系数较小，则电梯的载货或载客力量就越小。Therefore,tractioncoefficientindicatestractioncapacityoflift.Thelargerthetractioncoefficientis,thelargercapacityalifthasintermsofcargoorpassengerload;whilethesmallerthetractioncoefficientis,the20smallercapacityalifthas.保证电梯正常工作的曳引条件Requirementtoensureliftnormaloperation依据分析和计算，电梯在下面两种工作状态下应保证曳引绳在曳引轮绳槽上不出现打滑现象:Basedonanalysisandcalculation,tractionropeslipinthegroovecanbeavoidedwhenliftisineitherconditions:空载电梯在最高停站处上升制动状态(或下降起动状态)。Liftisdeceleratingbeforestoppingatthetoplandingorstartingupbyacceleratingfromthetoplanding.装有120%额定载荷的电梯，在最低停站处下降制动状态(或上升起动状态)。Forliftwith120%ratedload,liftisdeceleratingtowardsbottomlandingoracceleratingfromthebottomlanding.为了满足上述曳引条件，在设计曳引系数时应按以下公式进展:Tomeettheabovetractionrequirements,thetractioncoefficientshouldbecomputedaccordingtothefollowingformula:式中:Where:T1/T2125%额定负载的轿厢位于最底层站及空载轿厢位于最高层站的状况下，曳引轮两边曳引绳中的较大静拉力与较小静拉力之比;T1/T2–theratiooflargerstaticpullingforcetosmalleroneofthetractionropewhenliftwith125%ratedloadisatthebottomlandingorwithemptyloadatthetoplanding.C—与加速度、减速度有关的动力系数，C1=(g+a)/(g-a)，g1。am/sC1–thecoefficientrelatedtoaccelerationanddeceleration,C1=(g+a)/(g-a),2gisstandardaccelerationoffallingobject,g=9.8m/s.aisdecelerationof2carbeforestoppingoraccelerationofstar-upcar,measuredinm/s.C121MinimumpermissibleC1valueisasfollows:电梯的额定速度C值1LiftratedspeedCvalue1v?0.63m/s1.100.63m/s,v?1.00m/s1.151.00m/s,v?1.60m/s1.201.60m/s,v?2.50m/s1.251.25，11-1Whenvexceeds2.5m/s,C1shouldbecomputedaccordingtodifferentcircumstances,butmustnotlessthan1.25.Detailspleaseseetable1-1.C2C=1，VC=1.2。22C2–thecoefficientrelatedtogrooveshapealteration;forsemicirculargrooveortheonewithcut,C2=1;forVgroove,C1=1.21-1Table1-12 /m/s/m/s?C12LifttypeRatedspeed(m/s)Deceleration(m/s)0.630.51.107沟通双速,0.63ACdoublespeed0.71.154?1.0,1.00.91.2021.01.01.227沟通调速,1.0ACadjusting1.11.253?1.6speed,1.61.21.279221.61.21.279交(直)流无齿轮,1.6AC(DC)1.41.333?3.15gearless,3.151.61.390指紧急刹车时电梯的制动减速度?Decelerationwhenliftisjerking.MaximumtractioncapacityefαWhentractioncoefficientisdefinite,themaximumtractioncapacityshouldebecomputedasfollows:，G+0.5Q，P提上升度这一长度范围内的未被平衡的曳引钢丝绳的重量。Forexample:Gistheweightofcarwithemptyload,Qisratedload,G+0.5Qistheweightofcounterweight,Pistheweightofunbalancedtractionropeduringliftishoisted.(1)G+0.5QiftheweightofcounterweightisequaltoG+0.5Q,themaximumtractioncapacity当电梯有补偿链或补偿绳装置时，P=0;Whencompensationchainorcompensationropeisavailableinlift,P=0;(2)W，iftheweightofcounterweightisdefinite,givenitisW,themaximumtractioncapacity当电梯有补偿链或补偿绳装置时，P=0Whencompensationchainorcompensationropeisavailableinlift,P=0;允许的轿厢最小自重23Permissibleminimumweightofcar当空载轿厢位于最高停站处上升制动时，whencarwithemptyloadisdeceleratingtowardsthetoplanding,当装有125%额定负载的电梯位于最低停站处下降制动时，with125%ratedload,whentheliftisdeceleratingtowardsthebottomlanding,G/C1C2，假设轿厢自e/C1C2ek，Fromformula1-5and1-6,wecanseethatthesmallertheweightofcar―G‖is,fαthemoreitisapproaching/C1C2.Iftheweightofcarissmallenough,itisefαpossibletoexceed/C1C2.Undersuchcondition,slipoftractionropeintractioneropegroovewilloccur,sotheminimumweightofcarmustbelimited.电梯有补偿链或补偿绳装置时，式中P、k不存在。Ifcompensationchainorcompensationropedeviceisavailable,Pandkdonotexist.fαe，1.5(2)当时C1C224fαeif，1.5C1C2电梯有补偿链或补偿绳装置时，式中P、k不存在。Ifcompensationchainorcompensationropedeviceisavailable,PandKdonotexist.提高电梯曳引力量的方法Methodstoincr