【机械类文献翻译】采煤机.doc

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1、英文原文THESHEARERShearerLongwallequipmentconsistsofthreemajorcomponents:thehydraulicallypoweredroofsupport,thechainconveyor,andthecoal-cuttingmachine.Thetwodifferenttypesofcoal-cuttingequipmentusedincoalminesareshearersandplows.Plowsareusedinlowseams,42in.orle

2、ss.Theunitconsistsofsteelconstructionequippedwithcarbon-tippedbits.Thispassivesteelunitisengagedtoaguidingsystemonthefaceconveyor.Anendlessroundlinkchainpoweredbysynchronizedelectricdrivesoneachendofthefaceconveyorpullstheplowbodyatspeedsbetween120and420ft/

3、minalongtheface.Forthecuttingprocesstheplowhastobeforcedagainstthecoalface.Thisisdonebyhydrauliccylinderattachedtothegobsideofthefaceconveyorandtothebaseofthesupports,orbyaseparatehydraulicprop.Forcesofbetween1and3tonsareappliedpercylinder.Aplowdriveisattac

4、hedtoeachdriveframeofthefaceconveyor.Only30%to60%ofthedrivepowersuppliedtotheplowisusedforcuttingandloadingofcoal;theremainderislostinfriction.Thismeansthatthepowerlossisconsiderablyhigherthanthatofashearer,whichuses75%to85%ofitspowerfortheremovalofthecoal.

5、Asaresult,ratherlargedrivesarerequiredatthefaceends.Althoughtherearemanymodels,theshearerhasseveralcommonbasiccomponents.Adouble-endedranging-drumshearer(Fig.8.1),forexample,consistsoffourmajorcomponents:electricmotors,gearheads,haulageunit(powerpack),andcu

6、ttingdrums.Theelectricmotorrangingfrom300to1000horsepower(223~750kW)isthepowersourcefortheshearer.Itprovidespowertorunthehydraulicpumpsinthehaulageunitandthegearheadsforthecuttingdrum.Thelarge-capacityshearersaregenerallyequippedwithtwoelectricmotors:onefor

7、thehaulageunitandonegearheadandtheotherfortheothergearheadandotherancillaryequipment.Themotorscanberemotelycontrolled.Therearetwogearheads,oneontheleft-handtheotherontheright-handsideoftheshearer.Eachgearheradconsistsofagearheadgearboxandarangingarm.Thecutt

8、ingdrumislacedwithspiralvanesonwithspiralvanesonwhichthecuttingbitsaremounted.Itsdiameterrangesfrom34to72in.(0.86~1.83m)withrotationalspeedsfrom30to105rpm.Thetrendsaretowardfewerbutlargerbitsandslowerd