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外文翻译长臂式采煤用的采煤机.doc外文翻译长臂式采煤用的采煤机.doc

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编号:201311171437116627    类型:共享资源    大小:57.50KB    格式:DOC    上传时间:2013-11-17
  
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大学学士学位论文1附录一(英文)I.SHEARERLOADERSFORLONGWALLMININGInEurope,longwallminingiscomprehensivelymechanizedbythealmostexclusiveuseofshearerloadersandploughs.IntheFederalRepublicofGermanyploughinghasbeenappliedtoagreaterextentthaninothercoutries.Inspiteofthis,theproportionofcoalextractedbyshearerloadersissteadilyincreasing.Itaccountedfor36percentofthetotalnationaloutputinOctober1977.Thereareanumberofconvincingreasonswhyshearerloadersaregainingground.Theiroperationisessentionlymoreindependentofthefloorandroofconditions,dirtbandsandchangingseamconditionsthanthatofploughs.Optimumadaptationofthecuttingheight,thefixedcuttingdepth,andbetterroofcontrolarefurtherargumentsinfavourofshearerloaders.InOctober1976theeffectiveworkingtimeonaploughfacewasintherangeof35percent,comparedwith48percentonashearerface.Theaverageoutputsreflecttheaboxefigures(FRGOctober1977—1130tfromaploughface,1678tfromashearerface).Itshouldbenoticed,however,thatshearerloadersaregenerallyoperatinginseamsofgreaterthickness.Shearerloadersarenowavailableforseamsrangingfrom0.75mto4.50minthickness.Thevariousmachineversionsfortherespectiveoperatingconditionsencounteredareassembledfromagreatnumberofmajorcomponentsinaccordancewiththeunitprincipleofconstruction.Eickhoffshearerloaders,forinstance,canbeequippedwith大学学士学位论文2longitudinalmotorshavingratingsof170,200,and300kw,and450kwatpresentand230kwunitswillbeavailablesoon.Theshearerstravelonoralongsidetheconveyor.Rangingarmsofdifferentlengthfrom740mmto2230mmareavailable.Theshearerscanbemanufacturedtooperateonvariousvoltagesandfrequenciesgenerallyused,withvarioushaulagemethodsandspeeds,anddifferentdrumspeedsanddrumdesignforvariousmachineheights.Contrarytoformeryearsthemanufacturersofsuchmachinesarethereforenolongerinapositiontoproduceidenticalmachinesinlargeseries,butarecompelledtoassembletheminingmachinesfromalargenumberofexistingcomponentsaccordingtoprincipleswhichrequirecontinuousrevisionandimprovement,andtointegratethemintocompletesystemstogetherwiththefaceconveyorandroofsupportsasrequiredbytheminingconditionsencountered.Althoughahighdegreeofdevelopmentandgreatoperationalsafetyforthesevereoperatingconditionsundergroundhavealreadybeenreached,effortshavetobemadetodeveloptheminingmachinesfurtherwithaviewtomeetthefollowingfuturerequirements:(1)—increasedoutputs(andatthesametimeafurtherimprovementinoperationalsafety),(2)—Extensionoftheworkingrange(e.g.intosteeplyinclinedseams),(3)—Improvementoftheergonomicalconditions(e.g.reductionofdustmakeandnoise).IncreasedOutputsThecurrenttrendisformorecoaltobeextractedfromfewerfaces.大学学士学位论文3Theoutputfromsomefacesisalreadysohighthatevenshortstoppagesonafaceresultinanenormouslossofoutput.Therequiredincreaseofoutputsfromshearerloadersisthereforecloselyconnectedwiththerequirementforhigheroperationalsafety,abetterdegreeofutilisationandeasiermonitoringofallfunctionsofthemachine.Theimprovementinperformanceisthereforenotlimitedtothedevelopmentofmorepowerfulmotors,haulgeaboxes,gearheads,andrangingarms,butalsoincludestheelectricalmonitoringofthemachinesandeventuallyfullautomation.Thisalsoappliestothedevelopmentofcuttingtools,asthetoollifeandthetoolcostsaredecisivefortheperformanceofamachine.Outputscanalsobeincreasedbymulti-machineoperationonaface.Theefficiencycanbeimprovedbytheeliminationofstableholesandbyavoidingstoppagescaused,forinstance,bylargelumpsbreakingoutofthefaceandwhichmustbecrushedmanually.Itisalsoobviousthatthelimitationoftheoperatingvoltageto1000vsetsalimittoperformanceandthatthefurtherincreaseofthenominalmotorratingswillrequiretheintroductionofhighervoltages.ExtensionoftheWorkingRangeComprehensiveexperiencehasbeengainedwithshearerloadersinlevelandslightlyinclinedseamsorworkingstotherise.Theminingofthinseamsisaffectedbyinherentlimitationssetbytheheightoftheconveyor,thenecessaryclearanceunderneaththemachine,andtheheightofthemachineitself.Thinseamscanthereforeonlybeextractedbyshearerloadersifthemachinetravelsalongsidetheconveyor.大学学士学位论文4Thisresultsinguidingproblemswhichcannotbesolvedbytheuseofaguidingarrangementprovidedinthetravelingtrackonly.Asolutioneventuallyfoundwastotrapthemachineagainsttheconveyor.Thisopenedpossibilitiesfortheshearerloaderinaseamthicknesswhichsofarwasreservedfortheplough.AgreatnumberofEDW—170—LNshearersarenowoperating,particularlyinGreatBritainwheretheyextractthinseamsofhigh-gradecokingcoal.Insteeplyinclinedseamstheuseofshearerloadershasbeenlimitedduetohaulagedifficulties,andfindingadequatesafetydevicestoretainthesheareronthegradient.Newdevelopmentswhichdispensewithadditionalsafetydevicesoutsideofthemachineandwhichprovideforthenecessaryhaulagearrangementshaveextendedtheworkingrangeofshearerloadersintosteeplyinclinedseams.Thecostofroadwaydrivageandmaintenanceincreaseconsiderablywiththedepthoftheworkings.Thedevelopmentofadvancedheadinghassofarimpededfaceadvance.Thechainlesshaulagesystemforshearerloadersnowallowsformultimachineoperation.Withinsuchasystemfaceandmachinescanbeusedwhicharedesignedforthepurposeandwhichthusnotonlyeliminatestableholes,butalsocuttheroadwaysection,sothathighoutputsareachievedwiththeresultingincreasedproductivity.ImprovementofErgonomicalConditionsUndergroundComparedwithotherindustrialactivities,workingundergroundisparticularlylaboriousanddangerous.Effortsarethereforebeingmadetoeasethetasksandtoincreasethesafetyoftheworkingsundergroundnotonlybecauseofthenecessitytoobtainpeoplewhoarewillingtooperatethe
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