机械专业外文翻译中英文翻译优质文档.docx
- 文档编号:725491
- 上传时间:2022-10-12
- 格式:DOCX
- 页数:9
- 大小:29.76KB
机械专业外文翻译中英文翻译优质文档.docx
《机械专业外文翻译中英文翻译优质文档.docx》由会员分享,可在线阅读,更多相关《机械专业外文翻译中英文翻译优质文档.docx(9页珍藏版)》请在冰豆网上搜索。
机械专业外文翻译中英文翻译优质文档
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,commonlyreferredtoasflu
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- 机械 专业 外文 翻译 中英文 优质 文档