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TheInnovativeDesignofConstructHoistJiaWenhua,YinChenboInstituteofAutomobileandConstructionMachinery,NanjingUniversityoftechnology,Nanjing210009,P.R.ChinaAbstractInthispaper,thecurrentdevelopmentofconstructionhoistisreviewed.Thestructureandthecharacteristicsoftheconstructionhoistaredescribed.Thekeytechnologiessuchasthestructureofthediversityoftheconstruction,thetraction-liftconstruction,theintegratedwinchsystemandthecomputeraideddesignarediscussed.KeywordsConstructionmachineryhoist;Innovativedesign;Electro-hydraulic.1IntroductionTheconstructionhoistisakindofmechanicalmachineryusedtoliftpassengersandmaterialsalongtheverticalorrail-dumpingmast.Itiscomposedofplatforms,hopper,cageandsoon.Itcanhelptoimproveproductivityandreducecosts.Tomeettheneedsofdifferentkindsofconstructions,manynewtypesofconstructionhoistshavesprungupwhichhaveadvancedfunctions.2Innovativedesignofstructure2.1CommonstructureConstructionhoistscanbedividedintofourtypesaccordingtothenumberofcageandmast.TheirrelativepositionisshowninFig.1.abcd(a)doublemastandsinglecage(b)Singlemastandcagesonbothsides(c)Singlemastandacagesinoneside(d)SinglemastandacageinsideFig.1CommonstructurediagramThehoistshavebeenwidelyappliedinconstructiontoenhanceproductivityandconstructioncostsgreatly.Thestandardsectionsofhoistswitheithersinglemastsectionsordoublemastsectionsareallconnectedbybolts,andfixedonthewallbyconnections.Therearemechanicalspringsfixedonthebottomframeofthisinordertoincreasethereliabilities.2.2SeveralnewtypesofstructureThetilthoisthasrail-dumpingmasts,whichcanbeappliedwherethebuildingisnotvertical.Itsmastisparalleltothefadeofbuildings.Itiswidelyusedforchimneys,towers,bridgesandotherhigh-risetiltbuildings.Onefoldingandremovalhoistforlow-risebuildings’hasemergedinrecentyears.HefoldingandremovalhoistmadebyGermanBOCKERandithasagoodperformance.Thishoistcanpassthroughnarrowpassengerways,whenthestructureiscompact.Therailsectionsofthishoistcanrotate360aroundthebase,operatingeasilyandefficiently.Furthermore,therailsectionscanbeextendedandbendedsothatmaterialscanbetransportedconvenientlytotheroofofthebuildings.Accordingtothosesuperiorities,thistypehoistwillbeappliedwidelyinlow-risebuildings.Toadaptthetrendofenergy-savingandsafety,theeffectivewaystooptimizethemachineryhoistsarereductionofself-weightanddiversityofproductforms.TheMB-hoistsmadebyItalyMABERhasatrilateralcross-sectionmast.Thistypeofmastsectionscanreduceself-weightbutnotlowerperformance,anditcanreducecostandbeinstallmentquicklyandeasily.TheCM-doublemastcansharethemastwithothercageorplatform,sothatitovercomestheproblemoflowutilizationaboutthetraditionaldoublemasthoist,increasestheloadcapacity.Ingeneral,thistypehoistissuitableinthelarge-scalebuildingsformaterialorpassenger.3drivesysteminnovativedesignThedrivesystemisthecorepartofahoist,anditplaysasignificantroleintheadvanced,safeandcomfortablecharactersofahoist.3.1Rack-and-piniongearsdrivesystemUsingrack-and-piniongears,thedrivesystemhashighefficiencyandreliability.Therearetwotypesofconnectionbetweenthecageandthedrivesystem.Thefirsttypeisthatthedrivesystemarrangedwithinthecage.Itisfastenedonthehoist,drivingthehoistmovingdirectly.Anotheristhatthedrivesystemarrangeduponthecage,itisconnectedthecagebypins,drawingthehoistmovingindirectly.Theformoftheelasticfixingissimplerthanoftherigidfasteningandcancompensatefortheinfluenceandcancompensatefortheinfluenceofrack-and-piniongears,theseinfluencesincurredbytheerroroftheproductionandassembly.Theelasticfixingcanalsoavoidofthedamagesofthedrivesystemandplayabuffersothatthehoisthasastablebrake.3.2TractiondrivesystemThedrivesystemisdrivenbythetractor,andthespeedreduceroutputsthetorquetothedrayround.Thetractordriverthroughtheropesandthedrayroundthehoistmoving.Thetractorhastwotypesofrelativeplacement,underneathtypeandtop-installedtype.Becauseofthecomplexofthestructureandthehighercost,theunderneathtypehasnotbeenappliedwidely.AsshowinFig.2,themannedhoistwithtop-installedtractionmachinedevelopedbytheauthorsofthisFig.2Mannedwithtop-installedtractionmachinepaper,whosetractorisfixedonbeam.Thishoistusestheover-speedgovernorandthesafetygears.Whenthespeedreachesorsurpassesagivenvalue,theover-speedgovernorwillstopandpullthesafetygearstomoveinthemeantime,thecageisstoppedonthemast.Forthistypehoist,theproblemsaboutthecomplexstructureandcagecrashingweresolved.Becauseofalloftheseadvantages,thisnewtypehoistwillbeappliedwidely.3.3IntegratedwinchdrivesystemThewinchisanon-continuousworkingmachine,startingandbrakingfrequently.Itssafeoperationisveryimportantforthehoisting.Toavoidvarioussteelwiresofmutualrubbingandmulti-windingpilingup,thewinchshouldestablisharopearrangingdevice,andtheropedistanceisslightlybiggerthanthewirediameter.Meantime,thewirewindingheightofthedrumbetweentheoutersidesshouldhaveacertainsafealtitudes.Thisheightshouldnotbesmallerthan2timesofthewirediameter.Thevoltagefrequencyconvertersystemhasbeenusedinwinchdrivesystem.UsingtheVFCsystem,itisnotonlycansimplifythewiringcontrolbutalsocanadjustspeedconveniently,sothatthehoisthasas