Gear

GEARS齿轮Gearsworkinpairstodoajob.TheycanTHEROLEOFGEAR齿轮的作用Gearscanbeusedtodoseveralimportantthings:1)Transmitmotionandpowerbetweenrotatingshaft.传递运动和动力2)Reversingmotion(changingdirectionofmotion)GearsallowthetransferofrotationTHEROLEOFGEAR齿轮的作用Gearscanbeusedtodoseveralimportantthings:Theycanreversethedirectionofamotorordrive(clockwisetoanticlockwiseorviceversa)..用于改变传动方向。3)tochangetheaxisofmotion用于改变轴方向。Gearscanalsobeusedtochangetheaxisoftherotationofapowersource(changehorizontalaxisofrotationintoverticalaxisofmotionandvice-versa)Examples:Conversionofverticalmovementtransferredfromengineintohorizontalmovementofrearwheelsismadepossibleinthisway.THEROLEOFGEAR齿轮的作用Agearchangetherotationalmotionintorectilinearmotionandvice-versa.转动运动转变为直线运动,反之亦然3)ConversionofmotionGearisusedforconvertinglinearmotiontorotarymotionorviceversaTHEROLEOFGEAR齿轮的作用4)Modifytheamountofmotion改变运动速度Agearschangethemagnitudeofrotation,forexampleitcanincreaseordecreasetheturningspeedofamotor加速/减速.用于传递动力、改变转速。THEROLEOFGEAR齿轮的作用Gearsarewidelyknownasmachinecomponents.Gearsareusedaspumpsfortransportingvariousoilssuchasgasoline,dieselandlubricantoilsformechanicalequipmentExample:Gearoilpumps齿轮油泵5)Fluidtransportation(Gearpump齿轮泵)THEROLEOFGEAR齿轮的作用TypesofGears齿轮的种类Typesofgears齿轮的种类1.SpurGears:直齿圆柱齿轮Agearhavingtoothelementsthatarestraightandparalleltotheshaftaxisisknownasaspurgear.Aspurpaircanbeusedtoconnectparallelshaftsonly.▣Forconnectingparallelshafts轴线平行⒈Spurgear直齿圆柱齿轮—Theyareusedtotransmitmotionandpowerbetweentwoparallelshafts.直齿圆柱齿轮用于传递两平行轴间的动力和转速。Thepinionisthesmallestgearandthelargergeariscalledthegearwheel..externalcontact外啮合internalcontact内啮合Typesofgears齿轮的种类▣Forconnectingparallelshafts轴线平行Whentwospurgearsofdifferentsizesmeshtogether,thelargergeariscalledawheel(轮),andthesmallergeariscalledapinion(小齿轮).1.SpurGears:Thesmallergearisrotatingfaster,thelargergearisrotatinglessquickly.Typesofgears齿轮的种类▣Forconnectingparallelshafts轴线平行1.SpurGears:Typesofgears齿轮的种类▣Forconnectingparallelshafts轴线平行Gear‘A’iscalledthe‘driver’becausethisisturnedbyamotor.Asgear‘A’turnsitmesheswithgear‘B’anditbeginstoturnaswell.Gear‘B’iscalledthe‘driven’gear.Gearsareusedingroupsoftwoormore.Agroupofgearsiscalledageartrain齿轮系.Singlegeargeartrain齿轮系1.SpurGears:Typesofgears齿轮的种类▣Forconnectingparallelshafts轴线平行geartrain齿轮系An‘idler’gearisanotherimportantgear.Intheexampleoppositegear‘A’turnsinananticlockwisedirectionandalsogear‘C’turnsinananticlockwisedirection.The‘idler’gearisusedsothattherotationofthetwoimportantgearsisthesame.1.SpurGears:Typesofgears齿轮的种类▣Forconnectingparallelshafts轴线平行2.Helicalgears斜齿轮helicalgearingdiffersfromspurinthathelicalteeth，theteethofahelicalgearareinclinedatanangletotheaxisofrotationofthegear.Typesofgears齿轮的种类2.Helicalgears斜齿轮Helicalgears–Gearteethareinclinedtotheaxisofrotation.Helicalgearsallowspowertransferbetweenparallelandnon-parallelshafts.Typesofgears齿轮的种类2.Helicalgears斜齿轮Helicalgearsconnectparallelshaftsa)Singlehelicalgears单螺旋齿轮SinglehelicalgearsTypesofgears齿轮的种类▣Forconnectingparallelshafts轴线平行2.Helicalgears斜齿轮b)Doublehelicalgears双斜齿轮或Herringbonegears人字齿轮（Herringboneordoublehelicalgear）DoubleHelicalgearshavethefacewidthsplitintotwoequalpartswithteethofoppositespiral.DoublehelicalgearDoublehelical(continuous)Doublehelical(continuous)Typesofgears齿轮的种类▣Forconnectingparallelshafts轴线平行Crossedhelicalgears交错轴斜齿轮Crossedhelicalgearsareusedfortransmittingpowerbetweentwonon-parallel,non-intersectingshafts.CrossedhelicalgearsNeitherparallelnorintersectingshafts非平行Crossedhelicalgearsareidenticalwithotherhelicalgearsbutaremountedonnon-parallelshafts.2.Helicalgears斜齿轮Typesofgears齿轮的种类Forconnectingnon-parallelshafts非平行轴线Theteethofahelicalgearareinclinedatanangletotheaxisofrotationofthegear.▣Forconnectingtwoperpendicularaxes两齿轮轴线相交3.Bevelgears（Conicgear）锥齿轮、圆锥齿轮--Gearteethareformedonaconicalsurface锥形面andareusedmainlytotransmitpowerwithintersectingshafts轴线相交.Typesofgears齿轮的种类锥齿轮用于传递两垂直相交轴间的动力和转速。▣ForconnectingtwoperpendicularaxesTypesofgears齿轮的种类3.Bevelgears锥齿轮、圆锥齿轮Bevelgearsareoftenusedwheretwoshaftsareatrightangletoeachotherandtheircentrelineextensionsintersect.Rightangle：直角rightangletoeachotherformed90º—transmitpowerandmotionbetweenintersectingshaftsatright（90º）angles(twoperpendicularaxes）.Bevelgearsareusefulwhenthedirectionofashaft'srotationneedstobechanged.Theyareusuallymountedonshaftsthatare90degreesapart▣ForconnectingtwoperpendicularaxesTypesofgears齿轮的种类3.Bevelgears锥齿轮、圆锥齿轮straight-toothBevelGears:Theteethonbevelgearscanbestraight,spiralstraight-toothBevelGears:Typesofgears齿轮的种类3.TypesofBevelgears锥齿轮、圆锥齿轮SpiralBevelgearsUsedforhigherspeedsandquieteroperation.螺旋圆锥齿轮应用于在高速旋转和工作更平稳。SpiralBevelgearsTypesofgears齿轮的种类3.TypesofBevelgears锥齿轮、圆锥齿轮4.Hypoidgears双曲面齿轮Hypoidgearsresemblespiralbevels螺旋锥齿轮,buttheshaftaxesofthepinionanddrivengeardonotintersect.▣NeitherparallelnorintersectingshaftsConnectshaftswithaxisat900，butnotlyinginacommonplane..Typesofgears齿轮的种类HypoidgearsaresimilartoSpiralBevelgears,exceptthattheextensionsofthecentrelinesarenon-intersecting.Hypoidg