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1、电梯的电气系统维护毕业设计1.毕业实践任务书----------------------------------------------------------12.外文翻译---------------------------------------------------------------23.毕业实践调研报告--------------------------------------------------------104.毕业设计说明书----------------------
2、------------------------------------135.附录-------------------------------------------------------------------366．毕业设计总结-----------------------------------------------------------517.参考文献----------------------------------------------------------------
3、35Thehistoryandfutureoftheelevator75LifttheinventionprocessElevatoraccesstopeople'sliveshavebeen150years.1854,atCrystalPalaceinNewYorkWorld'sFair,American•ElishaGravesOtis•Thefirsttoshowtheworldhisinvention.Hestoodfullyloadedelevatorplatform,thecomma
4、ndassistantpulleduptotheplatformcanbefoundontheheightoftheaudience,andthensendasignalthathelperliftwiththeaxandcutoffthepullingcable.Surprisingly,aliftanddidnotcrash,butfirmlyfixedintheair-Mr.Otisinventedtheelevatorsafetydeviceplayedarole."Allsafe,ge
5、ntlemen."Standingonaliftplatform,Mr.Otiswavedaroundpeoplewatching.Noonewouldthink,thisisasafeliftofhumanhistory.Liftingtoolfortransportofgoodsforhumanuse,staffextremelylonghistory.Asearlyas2600BC,theEgyptiansbuiltthepyramidsontheuseofthemostoriginall
6、iftingsystem,thebasicprincipleofthissystemhasremainedunchanged:thatis,acounterweightisdeclining,theloadplatformrise.Fundamentaltotheearlyliftingofhuman-poweredtools.1203,theFrenchcoastinamonasteryandinstalledacranedrivenbydonkey,thisendedthehistorywi
7、ththehumantransportingheavyloads.Wattinventedthesteamengine,Britishscientists,thecranebegantousesteam-powereddevices.FollowedbyWilliamThomsondeveloped•Hydraulic-drivenlift,hydraulicmediumiswater.Onthebasisoftheselifts,generationaftergenerationofinnov
8、ativeengineerslifttechnologyisconstantlyimproving.However,akeysecurityissuehasnotbeenresolved,itispulleduptheropeoncetheliftwasbroken,theloadplatformtocrashwilloccur.Mr.Otisinventedthecompletelyrewrittenthehistoryofhumanuseliftingtools.Sincethen,take
