机械专业外文翻译带式输送机及其牵引系统Word格式.docx

机械专业外文翻译带式输送机及其牵引系统Word格式.docx

《机械专业外文翻译带式输送机及其牵引系统Word格式.docx》由会员分享，可在线阅读，更多相关《机械专业外文翻译带式输送机及其牵引系统Word格式.docx（9页珍藏版）》请在冰豆网上搜索。

机械专业外文翻译带式输送机及其牵引系统@#@外文翻译@#@英文原文@#@BeltConveyingSystemsDevelopmentofdrivingsystem@#@Amongthemethodsofmaterialconveyingemployed，beltconveyorsplayaveryimportantpartinthereliablecarryingofmaterialoverlongdistancesatcompetitivecost．Conveyorsystemshavebecomelargerandmorecomplexanddrivesystemshavealsobeengoingthroughaprocessofevolutionandwillcontinuetodoso．Nowadays，biggerbeltsrequiremorepowerandhavebroughttheneedforlargerindividualdrivesaswellasmultipledrivessuchas3drivesof750kWforonebelt（thisisthecasefortheconveyordrivesinChengzhuangMine）．Theabilitytocontroldriveaccelerationtorqueiscriticaltobeltconveyors’performance．Anefficientdrivesystemshouldbeabletoprovidesmooth，softstartswhilemaintainingbelttensionswithinthespecifiedsafelimits．Forloadsharingonmultipledrives．torqueandspeedcontrolarealsoimportantconsiderationsinthedrivesystem’sdesign.Duetotheadvancesinconveyordrivecontroltechnology，atpresentmanymorereliable．Cost-effectiveandperformance-drivenconveyordrivesystemscoveringawiderangeofpowerareavailableforcustomers’choices[1].@#@1Analysisonconveyordrivetechnologies@#@1．1Directdrives@#@Full-voltagestarters．Withafull-voltagestarterdesign，theconveyorheadshaftisdirect-coupledtothemotorthroughthegeardrive．Directfull-voltagestartersareadequateforrelativelylow-power,simple-profileconveyors．Withdirectfu11-voltagestarters．nocontrolisprovidedforvariousconveyorloadsand．dependingontheratiobetweenfu11-andno-1oadpowerrequirements，emptystartingtimescanbethreeorfourtimesfasterthanfullload．Themaintenance-freestartingsystemissimple，low-costandveryreliable．However,theycannotcontrolstartingtorqueandmaximumstalltorque；@#@therefore．theyarelimitedtothelow-power,simple-profileconveyorbeltdrives．@#@Reduced-voltagestarters．Asconveyorpowerrequirementsincrease，controllingtheappliedmotortorqueduringtheaccelerationperiodbecomesincreasinglyimportant．Becausemotortorque1safunctionofvoltage，motorvoltagemustbecontrolled．Thiscanbeachievedthroughreduced-voltagestartersbyemployingasiliconcontrolledrectifier（SCR）．AcommonstartingmethodwithSCRreduced-voltagestartersistoapplylowvoltageinitiallytotakeupconveyorbeltslack．andthentoapplyatimedlinearrampuptofullvoltageandbeltspeed．However,thisstartingmethodwillnotproduceconstantconveyorbeltacceleration．Whenaccelerationiscomplete．theSCRs,whichcontroltheappliedvoltagetotheelectricmotor．arelockedinfullconduction,providingfu11-linevoltagetothemotor．Motorswithhighertorqueandpull—uptorque，canprovidebetterstartingtorquewhencombinedwiththeSCRstarters,whichareavailableinsizesupto750KW．@#@Woundrotorinductionmotors．WoundrotorinductionmotorsareconnecteddirectlytothedrivesystemreducerandareamodifiedconfigurationofastandardACinductionmotor．Byinsertingresistanceinserieswiththemotor’srotorwindings．themodifiedmotorcontrolsystemcontrolsmotortorque．Forconveyorstarting，resistanceisplacedinserieswiththerotorforlowinitialtorque．Astheconveyoraccelerates，theresistanceisreducedslowlytomaintainaconstantaccelerationtorque．Onmultiple-drivesystems．anexternalslipresistormaybeleftinserieswiththerotorwindingstoaidinloadsharing．Themotorsystemshavearelativelysimpledesign．However,thecontrolsystemsforthesecanbehighlycomplex，becausetheyarebasedoncomputercontroloftheresistanceswitching．Today，themajorityofcontrolsystemsarecustomdesignedtomeetaconveyorsystem’sparticularspecifications．Woundrotormotorsareappropriateforsystemsrequiringmorethan400kW．@#@DCmotor．DCmotors．availablefromafractionofthousandsofkW，aredesignedtodeliverconstanttorquebelowbasespeedandconstantkWabovebasespeedtothemaximumallowablerevolutionsperminute（r/min）．withthemajorityofconveyordrives,aDCshuntwoundmotorisused．Whereinthemotor’srotatingarmatureisconnectedexternally．ThemostcommontechnologyforcontrollingDCdrivesisaSCRdevice．whichallowsforcontinualvariable-speedoperation．TheDCdrivesystemismechanicallysimple,butcanincludecomplexcustom-designedelectronicstomonitorandcontrolthecompletesystem．Thissystemoptionisexpensiveincomparisontoothersoft-startsystems．butitisareliable,cost-effectivedriveinapplicationsinwhichtorque,1oadsharingandvariablespeedareprimaryconsiderations．DCmotorsgenerallyareusedwithhigher-powerconveyors，includingcomplexprofileconveyorswithmultiple-drivesystems，boostertrippersystemsneedingbelttensioncontrolandconveyorsrequiringawidevariable-speedrange．@#@1．2Hydrokineticcoupling@#@Hydrokineticcouplings，commonlyreferredtoasf