凸輪機構設計外文文獻翻譯、中英文翻譯、外文翻譯

1、6.1英文原文CamsVariousmotionscanbeproducedbytheactionofacamagainstafollower.Mamytimingdevicesareoperatedbycanaction.Thepurposeofandycamistoproduceadisplacementofitsfollower;asecondaryfollowerisoften.usedtoproduceadditionaldisplacementinanotherlocation.Themostpopulartypeistheplatecam.Thecylindricaltypeis

2、usedtotransmitlinearmotiontoafollowerasthecamrotates.Three-dimensionalcamaresometimesused;theseprovidesomeunusualfollowermotions,butalsomakefollowerdesigndifficult.Thecamshaftintheautomotiveengineillustratesasimplebutimportantapplicationofalatecam.Thecamassembliesinautomaticrecordplayersillustrateas

3、omewhatmorecomplexapplication.Camprofilesareaccuratelyconstructedbyeitherpraphicalormathematicalmethods.Thetransitiomfromdevelopmentdrawingstoworking(shop)drawingcanbemadeinseveralways:.Makeafull-scaletemplate.Thisisdesirablefromthemanufacturingstandpoint,butitwillnotguaranteeaccuratecamprofiles.Use

4、radialdimensions.Thisisfairlyaccurate,butsometimesproduceslayoutproblemsintheshop.Usecoordinatedimensioning.Thisprocedurewillensureaccuracy.Inselecringoneofthesemethods,oneshouldconsiderthefunctionofthecamintermsofdesiredpreciseness.Becausethecamworkoutlinealreadydetermined,thereforethecamstructural

5、designmainlywasdeterminesthecurveoutlineaxialthicknessandthecamandthedriveshaftconnectionway.Whentheworkloadcomparesthehour,curveoutlineaxialthicknessgenerallytakesfortheoutlinecurvebiggestradiusofvector1,/10/5;Regardingastressbiggerimportantsituation,mustwithcarryonthedesignaccordingtothecamcontour

6、surfacefromthecontactintensity.Whendeterminationcamanddriveshaftjointway,shouldsynthesizetheconsiderationcamtheassemblinganddismantling,theadjustmentandfirmlygradesthequestion.Regardingimplementingagencymoreequipment,betweenitseachexecutioncomponentmovementcoordinationusuallydeterminedbythecycleofmo

7、tionchart,thereforeinassemblycamgeartime,thecamcontourcurveinitialstation(pushesregulationstarts)therelativepositiontohaveaccordingtothecycleofmotioncharttocarryontheadjustment,guaranteeseachexecutioncomponenttobeableaccordingtothepre-setsequencesynchronizedaction.Therefore,requeststhecaminthestruct

8、uraldesigntobeabletobeoppositetothedriveshaftcarriesontherotationalongthecircumferencedirection,andreliablyperformsfixedly.Thesimplestmethodusestheclampingscrewnailfixedcam,orwithclampingscrewnailpre-fixed,aftertreatsadjustsusesthepintobefixedagain.Fromstructuraldesign:fromstructure:Whendesignmustco

9、nsiderfromtheguidanceandpreventedrevolves.Frommovementruledesign:Involvesmanyaspectsfromthemovementruledesignthequestions,besidesconsiderationrigidityimpactandflexibleimpact,butalsoshouldmaximumspeedvmaxwhichhastoeachkindofmovementrule,maximumaccelerationamaxanditstheinfluenceperformsthecomparison.1

10、)vmaxbigger,thenmomentummvisbigger.Iffromissuddenlyprevented,theoversizedmomentumcancausetheenormousimpulse,endangerstheequipmentandthepersonalsafety.Therefore,whenisbiggerfromthequality,inordertoreducethemomentum,shouldchoosethevmaxvaluesmallermovementrule.2)amaxbigger,isbigger.Functioninhighvice-c

11、ontactplacestressbigger,theorganizationintensityandthewearresistantrequestisalsohigher.Regardinghighspeedcam,inordertoreducetheharm,shouldchoosetheamaxvaluesmallermovementrule.Firststatesseveralkindofmovementsrulesvmax,amax,theimpactcharacteristicandthesuitablesituationfollowingtableregardingswingsf

12、romthecamgear,itsmovementgraphx-coordinateexpressioncamcorner,y-coordinatethenseparatelyexpressesfrom,angularspeedandangleacceleration.Thiskindofmovementgraphhasthestateofmotionandaboveissame.Fromstructuraldesign:fromstructure:Whendesignmustconsiderfromtheguidanceandpreventedrevolves.Frommovementrul

13、edesign:Thecamgeardesignbasicquestion1.camgearstypechoice,thedefinitecamshape,withfrommaintainsthehighvice-contactfromtheshapeandthemovementformandthecamtheway2.fromthemovementruledesign,accordingtotheapplicationsituationtofromthetravellingscheduleandthestateofmotionrequest,determinesfromthemovement

14、rule.3.camgearsbasicparameterdesign,determinesfromthetravellingschedule,variousmovementsangle,thecamradius,therollerradius,thecenterdistance,fromthelengthandsoon.4.camcontourscurvedesign.5.camgearsbearingcapacitycomputation.6.camgearsstructuraldesign,planorganizationassemblydrawingandvariouscomponen

15、tsshopdrawingFromstructuraldesign:fromstructure:Whendesignmustconsiderfromtheguidanceandpreventedrevolves.Frommovementruledesign:Thecamgeardesignbasicquestion1.camgearstypechoice,thedefinitecamshape,withfrommaintainsthehighvice-contactfromtheshapeandthemovementformandthecamtheway2.fromthemovementrul

16、edesign,accordingtotheapplicationsituationtofromthetravellingscheduleandthemovement1,thecamgearapplicationcamgearisincludesthecamthehighvice-organization,thecamgearhasthestructuretobesimple,mayaccuratelyrealizerequestmeritandsoonmovementrule,thusobtainsthewidespreadapplicationintheindustrialproducti

17、on,speciallyautomaticdeviceandintheautomaticcontroldevice,obtainsthewidespreadapplication.2nd,thecamgearclassificationaccordingtotwomovestherelativemotioncharacteristicclassificationbetweenthecomponent(1)theplanecamgear1)thediskcam;2)translationcam.(2)spacecamgearaccordingtofrommovementvice-elements

18、hapeclassification(1)apexfrom;(2)rollerfrom(3)flatbasefrom.Note:Classifiesthispartofcontentwhentheintroductioncamgear,shouldpointouteachkindofcamgearthegoodandbadpointsanditstheadaptionsituation,showedeachkindofcamgeartheinnerlink,willbuildthefoundationforthelatertranslationcamandthecolumncamcontour

19、design.3rd,thethrowoutlevermovementrule(1)thecamgearcycleofmotionandthebasictermterminologypushtheregulationmovementangle:Withfrompushesthecamcornerwhichtheregulationcorresponds;Farstopstheangle:Withfromfarreststhecamcornerwhichtheregulationcorresponds;Returntripmovementangle:Withcamcornerwhichcorre

20、spondsfromthereturntrip;Nearlystopstheangle:Withfromnearlyreststhecamcornerwhichtheregulationcorresponds;Cam:Takethecamaxlecenterasthecenterofacircle,takeitsoutlineslightlytodiameterr0astheradiuscircle;Fromravellingschedule:Inpushesintheregulationorthereturntripfromthebiggestdisplacement,indicatedwi

21、thh;:Thecamcenterofrotationwithfromguideswaythebiasdistance,indicatedwithe.TypesofCamsPlatecamsaresimpletofabricate.Thefollowercanbemovedinvariouspatternswithvariousrise/fallratios.Motionshouldbecontrolledtoavoidabruptchangesinforcetransmittedfromthecamtothefollower.Oneshouldcarefullydeterminehorizo

22、ntalforcecomponents,sincethesepresentproblemsdesigningthefollowerassemblyguide.CriticalreactionsoccuratpointsAandB.Thesereactionvaluesmustbecomputed.TherelativeverticalpositionofpointAwithrespecttoBneedstoberaisedifthereactionvalueatBisexcessive.ThepositionofBshouldbeasclosetocamaspossibletominimize

23、flexureintheroller-followersupport.Thistypeproducesreciprocatingmotioninthefollower.Again,dorcesneedtobedeterminedanddimensionschosensoastoavoidexcessivecomponentsizes.Ataperedrollerfollowerisfrequentlyemployed;thegrooveintheperipheryofthecamshouldbeshapedtoaccommodatethefollower.Thistypeofcamisexpe

24、nsivetoproduce.Thecylindricalcamhastwooutstandingfeatures.Oneisthefactthatthecamispositiveactiong.Noutsideforces(suchasgravityorspringaction)areneededtoholdthefolloweragainsttheworkingsurfaceofthecam.Thesecondfeatureisthefactthatthefollowercanmovethroughacompletecycleinthecourseofseveralrevolutionso

25、fthecam.Forexample,itispossibletodesignthecamsothefollowercouldmovefromastartingpositionattheleftendtotheextremerightpositioninthreerevolutions(ormore),thenthestartingpositionintworevolutions.Othervariationsarepossible.Atranslationcamisillustrated.Inthefigureshownthecamreciprocateshorizontallyandthe

26、followermovesupanddown.Apivotedfollowercanbeusedwiththistype.Thetranslationcamcanbemadepositivebyprovidingaguidedplatewithaninclinedslotforthecam;theslotcamthenengageapinorrolleronaguidedverticalreciprocatedfollower.Withthelattertype,however,acompleteforceanalysisisacriticalphaseofthedesign.Inthisty

27、pe,thecamrotatesandthefollower(ususllyarollerorpin)isguidedbyagroovecutintotheendfaceofacylindricalsection.Rotationofthecamprovidestranslationofthefollower.Thistypeisalsopositiveacting.Productioncostsforthistypeofcamaremuchhigherthanforasimpleplatecam.Aconstant-diametercamisillustrated.Thisismerelya

28、circularplatewiththecamshaftholeeccentricallylocated.Theamountofeccentricitydeterminestheamountoffollowerdisplacement.Asthecamrotates,thefollowerreciprocates.ThisarrangementissometimesknownasaScotchyokemechanism.Followeractionispositive;harmonicmotionisproducedbythistypeofarrangement.TypesofFollower

29、sInneneral,thefollowerisconsideredtobethepartthatcomesincontactwiththecamprofile.However,whenasecondayfollowerisused,themotionofthesecondaryfollowerisdictatedbythatoftheprimaryfollower.Forexample,arollerfollowercanbereciprocatedbyactingagainsttheedgeofapivotedfollower.Thesimplesttypeoffolloweristher

30、eciprocationgtypethatmerelymovesupanddown(orinandout)withtherotationofthecam;thecenterlinecanbeeithercollinearwiththecamcenterlineoroffsetfromit.Contactwiththecamcanbeviaapoint,aknifeedge,asuface,oraroller.Aflat-afcedreciprocatingfollowerisshownIfapointorsurfaceisemployedforcontactthehighnormalforce

31、canresultinabrasionandexcessivewear.Iftheloadbeingtransmittedfromthecamtothefollowerissmall,theproblemisnotserious.Forexample,theoperationofasmallsnap-actionswitchdoesnotproducecamsurfacewear.Miniaturesnap-actionelectricalswitcheshaveactuatorswithvariousconfigurations;someoftheseareintheformofrounde

32、dpointsorthinmetasections.Miniaturethree-wayvalvesinaircircuitshavesimilaractuators.Ifcamsareusedtooperatemechanicalcomponentsdirectly,arollerismuchmoreeffective.Camrollersarecommerciallyavailableinrollersizesrangingfrom1/2in.to6inBasicdynamiccapacitiesrangefrom620to60000,basedon33.33rpmand500hrofmi

33、nimumlife.Correctionfactorsmustbeusedforanyotherspeedorlifevalues.Itshouldbenotedthatthecamcanbelubricatedthroughandoilholeintheendoftheshank.Rollingcontactwiththecamsurfaceminimizeswearproblems.Severalmountingarrangementsarepossiblewiththistypeoffollowr.showstherollerfollowermountedonapivotedarm.Ap

34、ivotedflat-facedfollowerisshown.Aswithanyflat-facedfollower,frictionbetweenthefollowerfaceandthecamprofilemustbecontrolled.Properlubricationcanreducetheeffectsoffriction.6.2漢語翻譯:凸輪通過凸輪和從動件的作用，可得到不同的運動。許多計時裝置由凸輪驅動。使用凸輪的目的是使其從動件產生位移，次級從動件常用來在另一位置產生附加位移。最常用的凸輪是盤形凸輪。圓柱凸輪用來將其旋轉運動轉變?yōu)閺膭蛹闹本€運動。最常用的凸輪是盤形凸輪。圓

35、柱凸輪用來將其放置運動轉變?yōu)閺膭蛹闹本€運動。有時也用三維凸輪，它們提供一些不建黨的從動件運動，也使從動件設計難度加大。汽車發(fā)動機上的凸輪軸顯示了盤形凸輪的簡單和重要的應用場合，錄音機上的凸輪組件是更復雜的應用實例。凸輪輪廓可用作圖法或數(shù)學計算法來精確設計，將設計圖轉換成加工圖可用下面幾種方法：1制造一個實尺樣板。這是制造需要，但不能保證精確的凸輪輪廓。2使用徑向尺寸設計。這相當精確，但在生產時有時會產生排布問題。3用座標尺寸設計。這種方法能保證精度。選用這些方法時，應按要求的精度考慮凸輪的作用。凸輪的結構設計：因凸輪的工作輪廓已經確定，所以凸輪的結構設計主要是確定曲線輪廓的軸向厚度和凸輪與傳

36、動軸的連接方式。當工作載荷較小時，曲線輪廓的軸向厚度一般取為輪廓曲線最大矢徑的1/101/5；對于受力較大的重要場合，需按凸輪輪廓面與從動件間的接觸強度進行設計。在確定凸輪與傳動軸的聯(lián)接方式時，應綜合考慮凸輪的裝拆、調整和固定等問題。對于執(zhí)行機構較多的設備，其各執(zhí)行構件之間的運動協(xié)調性通常由運動循環(huán)圖確定，因此在裝配凸輪機構時，凸輪輪廓曲線起始點（推程開始點）的相對位置需按運動循環(huán)圖進行調整，以保證各執(zhí)行構件能按預定程序協(xié)調動作。為此，在結構設計上要求凸輪能相對于傳動軸沿圓周方向進行轉動，并可靠地加以固定。最簡便的方法是采用緊定螺釘固定凸輪，或用緊定螺釘預固定，待調整好后再用銷子固定。從動件的

37、結構設計：直動從動件的結構：設計時要考慮從動件的導向和防止旋轉。從動件運動規(guī)律的設計:從動件運動規(guī)律的設計涉及許多方面的問題，除考慮剛性沖擊和柔性沖擊外，還應對各種運動規(guī)律所具有的最大速度vmax、最大加速度amax及其影響加以比較。vmax愈大，則動量mv愈大。若從動件突然被阻止，過大的動量會導致極大的沖擊力，危及設備和人身安全。因此，當從動件質量較大時，為了減小動量，應選擇vmax值較小的運動規(guī)律。amax愈大，慣性力愈大。作用在高副接觸處的應力愈大，機構的強度和耐磨性要求也就愈高。對于高速凸輪，為了減小慣性力的危害，應選擇amax值較小的運動規(guī)律。前述幾種運動規(guī)律的vmax、amax、沖

38、擊特性及適用場合如下表對于擺動從動件凸輪機構，其運動線圖的橫坐標表示凸輪轉角，縱坐標則分別表示從動件的角位移、角速度和角加速度。這類運動線圖具有的運動特性與上述相同。凸輪機構設計的基本問題凸輪機構類型選擇，確定凸輪形狀、從動件形狀與運動形式及凸輪與從動件維持高副接觸的方式從動件運動規(guī)律設計，根據應用場合對從動件行程和運動特性的要求，確定從動件運動規(guī)律。凸輪機構基本參數(shù)設計，確定從動件行程、各運動角、凸輪基圓半徑、偏距、滾子半徑、中心距、從動件長度等。凸輪輪廓曲線設計。凸輪機構承載能力計算。凸輪機構結構設計，繪制機構裝配圖和各零件的工作圖。凸輪機構的應用凸輪機構是含有凸輪的高副機構，凸輪機構具有

39、結構簡單，可以準確實現(xiàn)要求的運動規(guī)律等優(yōu)點，因而在工業(yè)生產中得到廣泛的應用，特別是自動機械和自動控制裝置中，得到廣泛的應用。凸輪機構的分類按兩活動構件間的相對運動特性分類(1)平面凸輪機構1)盤形凸輪；2)移動凸輪。(2)空間凸輪機構按從動件運動副元素形狀分類(1)尖頂從動件；(2)滾子從動件；(3)平底從動件。注：在介紹凸輪機構分類這部分內容時，應指出各種凸輪機構的優(yōu)缺點及其適應場合，說明各種凸輪機構的內在聯(lián)系，為以后的移動凸輪及圓柱凸輪輪廓的設計打下基礎。推桿的運動規(guī)律(1)凸輪機構的運動循環(huán)及基本名詞術語推程運動角：與從動件推程相對應的凸輪轉角；遠休止角：與從動件遠休程相對應的凸輪轉角；回程運動角：與從動件回程相對應的凸輪轉角；近休止角：與從動件近休程相對應的凸輪轉角；凸輪基圓：以凸輪軸心為圓心,以其輪廓最小向徑r0為半徑的圓