《凸轮机构讲义》PPT课件

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1、Chapter4.CamsandItsDesignSunZhihongZhsun@dhu.edu.cn67792580Today’stopicsCharacteristicsofcammechanisms凸轮机构的特点Classificationandapplicationofcammechanisms凸轮机构的分类及应用Thefollower’smotiontype从动件的运动形式Whatisacammechanism?Asystem/mechanismthatusesacam(凸轮)andafollower(从动件)tocreateaspecificmotion.Inmo

2、stcases,thecamismerelyaflatpieceofmetalthathasanunusualshapeorprofile(轮廓).Thecamisattachedtoashaft(轴)whichenableittobeturnedbyapplyingaturningactiontotheshaft.Asthecamrotates,itistheprofileorshapeofthecamthatcausesthefollowertomoveinaparticularway.Themovementofthefolloweristhentransmitted(传

3、递)toanothermechanismoranotherpartofthemechanism.AdvantagesofcammechanismsSimpleandcompact(简单、紧凑)–thereonlythreelinks,cam(凸轮),follower(从动件),frame(机架).Sometimes,thereisaroller(滚子).Thefollowercanpreciselyrealizeanytypemotion.ExampleDisadvantagesofcammechanismsHigherpair(高副),linecontactorpointc

4、ontact(线或点接触)Can’ttransfer(传递)largepower.FunctionContinuousturningmotion→translating(往复移动)oroscillating(摆动)motion.ExampleApplicationofcammechanismCamshaft（凸轮轴）ofanEngineincorporatingaRockerArm（摆臂）:Thediagramshownrightisatypicalcamandfollowersystemthatcouldbeusedinanengine. Thissystemincorpo

5、ratesarockerarm.Inthiscasethemotionthatthecamimpartsonthefolloweristranslatedtothevalvethroughapushrodandtherockerarm.Dobby多臂提花机作者：潘存云教授绕线机构3作者：潘存云教授12Ayarn线Yarnwindingmachine(绕线机)作者：潘存云教授132送料机构Feedingmechanism送料机构FeederofAutomaticMachineTools自动机床的进刀机构园柱凸轮回转→滚子带动推杆往复摆动→刀架的进刀和退刀12刀架o机床进给机构1

6、3245放音键卷带轮皮带轮摩擦轮录音机卷带机构3皮带轮5卷带轮录音机卷带机构1放音键2摩擦轮4录音机卷带机构织机开口机构Classificationofcammechanism凸轮机构的分类Bythecamshape(按凸轮形状分)Bythefollowershape(按从动件类型分)Bythefollower’smotiontype(按从动件运动形式分)Bythemannerofkeepingthecamandthefollowerincontact(按从动件与凸轮的锁合方式分)Edge,plateorfacecams盘状凸轮Translatingcams移动凸轮Cylin

7、dricalordrumcams圆柱凸轮Bythefollowerend’sshapeKnife-edgefollower尖顶从动件Theendofthefollowerisverysharp(nearlyapoint)ThecontactbetweenthecamandthefollowerisapointThefolloweriseasytobeworn.It’srarelyused.作者：潘存云教授Bythefollowerend’sshapeDiskcamwithrollerfollower