機(jī)械類外文文獻(xiàn)翻譯

文獻(xiàn)翻譯英文原文：NOVELMETHODOFREALIZINGTHEOPTIMALTRANSMISSIONOFTHECRANK-AND-ROCKERMECHANISMDESIGNAbstract:A novel methodof realizing the optimal transmissionof thecrank-and-rockermechanismispresented.Theoptimalcombinationdesignismadebyfindingtherelatedoptimaltransmissionparameters.Thediagramoftheoptimaltransmissionisdrawn.Inthediagram,therelationamongminimumtransmissionangle,thecoefficientoftravelspeedvariation,theoscillatingangleoftherockerandthelengthofthebarsisshown,concisely,convenientlyanddirectly.Themethodpossessesthemaincharacteristic.Thatitistoachievetheoptimaltransmissionparametersunderthetransmissionanglebydirectlychoosinginthediagram,accordingtothegivenrequirements.Thecharacteristicsofthemechanicaltransmissioncanbeimprovedtogaintheoptimaltransmissioneffectbythemethod.Especially,themethodissimpleandconvenientinpracticaluse.Keywords：Crank-and-rockermechanism,Optimaltransmissionangle,CoefficientoftravelspeedvariationINTRODUCTIONByconventionalmethodofthecrank-and-rockerdesign,itisverydifficulttorealizetheoptimalcombinationbetweenthevariousparametersforoptimaltransmission.Thefigure-tabledesignmethodintroducedinthispapercanhelpachievethisgoal.Withgivenconditions,wecan,byonlyconsultingthedesigningfiguresandtables,gettherelationsbetweeneveryparameterandanotherofthedesignedcrank-and-rockermechanism.Thustheoptimaltransmissioncanberealized.Theconcerneddesigningtheoryandmethod,aswellastherealcasesofitsapplicationwillbeintroducedlaterrespectively.1 ESTABLISHMENTOFDIAGRAMFOROPTIMALTRANSMISSIONDESIGNItisalwaysoneofthemostimportantindexesthatdesignerspursuetoimprovetheefficiencyandpropertyofthetransmission.Thecrank-and-rockermechanismiswidelyusedinthemechanicaltransmission.Howtoimproveworkabilityandreduceunnecessarypowerlossesisdirectlyrelatedtothecoefficientoftravelspeedvariation,theoscillatingangleoftherockerandtheratioofthecrankandrocker.Thereasonablecombinationoftheseparameterstakesanimportanteffectontheefficiencyandpropertyofthemechanism,whichmainlyindicatesintheevaluationoftheminimumtransmissionangle.Theaimrealizingtheoptimaltransmissionofthemechanismishowtofindthemaximumoftheminimumtransmissionangle.Thedesignparametersarereasonablycombinedbythemethodoflesseningconstraintsgraduallyandoptimizingseparately.Consequently,thecompleteconstraintfieldrealizingtheoptimaltransmissionisestablished.Thefollowing stepsaretakenintheusualdesignmethod.Firstly,theinitialvaluesofthelengthofrockerl3andtheoscillatingangleofrockeraregiven.ThenthevalueofthecoefficientoftravelspeedvariationKischoseninthepermittedrange.Meanwhile,thecoordinateofthefixedhingeofcrankAporealizediscalculatedcorrespondingtovalueK.1.1Lengthofbarsofcrankandrockermechanism.TheAsshowninFig.1,leftarcC2GisthepermittedfieldofpointAcoordinatesofpointA arechosenbysmallstepfrompointC2topointG.ThecoordinatesofpointA areyAyc2h0(1)xA22(2)RyAwhereh0,thestep,isincreasedbysmallincrementwithinrange(0,H).Ifthesmallerthechosenstepis,thehigherthecomputationalprecisionwillbe.R istheradiusofthedesigncircle.d isthedistancefromC2 toG.dl3cos2Rcos()l3cos(3)222CalculatingthelengthofarcAC1 andAC2,thelengthofthebarsofthemechanismcorrespondingtopointA isobtained[1,2].1.2Minimumtransmissionangle minMinimumtransmissionangle[3]min(seeFig.2)isdeterminedbytheequationscoscos

22(l42l2l3l1)min2l2l3l22l32(l4l1)2max2l2l3

(4)(5)m in 180 m ax (6)where l1——Lengthofcrank(mm)l2——Lengthofconnectingbar(mm)l3——Lengthofrocker(mm)l4——Lengthofmachineframe(mm)Firstly,wechooseminimumcomparing min with min .Andthenwerecordallvaluesof min greaterthanorequalto40 andchoosethemaximumofthem.Secondly,wefindthemaximumof min correspondingtoanyoscillatinganglewhichischosenbysmallstepinthepermittedrange(maximumofmin isdifferentoscillatingangle andthecoefficientoftravelspeedvariationK).Finally,wechangethelengthofrockerl3 bysmallstepsimilarly.Thuswemayobtainthemaximumof

min

correspondingtothedifferentlengthofbars,differentoscillatingangle

andthecoefficientoftravelspeedvariation

K

.Fig.3isaccomplishedfromTableforthepurposeofdiagramdesign.Itisworthpointingoutthatwhateverthelengthofrockerl3 isevaluated,thelocationthatthemaximumof min arisesisonlyrelatedtotheratioofthelengthofrockerandthelengthofmachineframel3/l4,whileindependentofl3.2 DESIGNMETHOD2.1RealizingtheoptimaltransmissiondesigngiventhecoefficientoftravelspeedvariationandthemaximumoscillatingangleoftherockerThedesignprocedureisasfollows.(1)AccordingtogivenKand,takenaccounttotheformulatheextremeincludedangleisfound.Thecorrespondingratioofthelengthofbarsl3/l4isobtainedconsultingFig.3.K1(7)K1801(2)Choosethelengthofrockerl3accordingtotheworkrequirement,thelengthofthemachineframeisobtainedfromtheratiol3/l4.(3)ChoosethecentreoffixedhingeDasthevertexarbitrarily,andplotanisoscelestriangle,thesideofwhichisequaltothelengthofrockerl3(seeFig.4),andC1DC2

.ThenplotC2M C1C2,drawC1N,andmakeangleC2C1N 90 .ThusthepointofintersectionofC2M andC1N isgained.Finally,drawthecircumcircleoftriangle PC1C2.(4)PlotanarcwithpointD asthecentreofthecircle,l4astheradius.ThearcintersectionsarcC2G atpoint A.Point A isjustthecentreofthefixedhingeofthecrank.Therefore,fromthelengthofthecrankl1(AC1AC2)/2(8)andthelengthoftheconnectingbarl2AC1l1(9)wewillobtainthecrankandrockermechanismconsistedofl1,l2,l3,andl4.Thustheoptimaltransmissionpropertyisrealizedundergivenconditions.2.2Realizingtheoptimaltransmissiondesigngiventhelengthoftherocker(orthelengthofthemachineframe)andthecoefficientoftravelspeedvariationWetakethefollowingsteps.(1)Theappropriateratioofthebarsl3/l4canbechosenaccordingtogivenK.Furthermore,wefindthelengthofmachineframel4(thelengthofrockerl3).(2)ThecorrespondingoscillatingangleoftherockercanbeobtainedconsultingFig.3.Andwecalculatetheextremeincludedangle .15.Then,Thenrepeat(3)and(4)insection2.13 DESIGNEXAMPLETheknownconditionsarethatthecoefficientoftravelspeedvariationK 1.1818 andmaximumoscillatingangle 40 .Thecrankandrockermechanismrealizingtheoptimaltransmissionisdesignedbythediagramsolutionmethodpresentedabove.First,withEq.(7),wecancalculatetheextremeincludedanglewefindl3/l40.93consultingFig.3accordingtothevaluesofand.Ifevaluatel350mm,thenwewillobtainl450/0.9353.76mm.Next,drawsketch(omitted).Asresult,thelengthofbarsisl116mm,l246mm,l350mm,l453.76mm.Theminimumtransmissionangleismin

l22l32(l4l12)arccos2l2l346.3698Theresultsobtainedbycomputerarel1 16.2227 mm,l2 44.5093 mm,l3 50.0000 mm,l4 53.8986 mm.ProvidedthatthefiguredesigniscarriedundertheconditionoftheAutoCADcircumstances,veryprecisedesignresultscanbeachieved.4 CONCLUSIONSAnovelapproachofdiagramsolutioncanrealizetheoptimaltransmissionofthecrank-and-rockermechanism.Themethodissimpleandconvenientinthepracticaluse.Inconventionaldesignofmechanism,taking0.1mmasthevalueofeffectivetheprecisionofthecomponentsizeswillbeenough.譯文：認(rèn)識曲柄搖臂機(jī)構(gòu)設(shè)計(jì)的最優(yōu)傳動(dòng)方法摘要：一種曲柄搖臂機(jī)構(gòu)設(shè)計(jì)的最優(yōu)傳動(dòng)的方法被提出。 這種優(yōu)化組合設(shè)計(jì)被用來找出最優(yōu)的傳遞參數(shù)。得出最優(yōu)傳遞圖。在圖中，在極小的傳動(dòng)角度之間 ,滑移速度變化系數(shù)，搖臂的擺動(dòng)角度和桿的長度被直觀地顯示。這是這種方法擁有的主要特征。根據(jù)指定的要求，它將傳動(dòng)角度之下的最優(yōu)傳動(dòng)參數(shù)直接地表達(dá)在圖上。通過這種方法，機(jī)械傳動(dòng)的特性能用以獲取最優(yōu)傳動(dòng)效果。特別是，這種方法是簡單和實(shí)用的。關(guān)鍵字：曲柄搖臂機(jī)構(gòu) 最優(yōu)傳動(dòng)角度 滑移速度變化系數(shù)介紹由曲柄搖臂機(jī)構(gòu)設(shè)計(jì)的常規(guī)方法,在各種各樣的參量之間很難找出優(yōu)化組合的最優(yōu)傳動(dòng)。通過本文介紹的圖面設(shè)計(jì)方法可以幫助達(dá)到這個(gè)目的。在指定的情況下，通過觀查設(shè)計(jì)圖面,我們就能得到每個(gè)參量和另外一個(gè)曲柄搖臂機(jī)構(gòu)設(shè)計(jì)之間的聯(lián)系。由因認(rèn)識最優(yōu)傳動(dòng)。具體的設(shè)計(jì)的理論和方法， 以及它們各自的應(yīng)用事例將在以下介紹。優(yōu)化傳動(dòng)設(shè)計(jì)的建立優(yōu)化傳動(dòng)的設(shè)計(jì)一直是設(shè)計(jì)師改進(jìn)傳輸效率和追求產(chǎn)量的最重要的索引的當(dāng)中一個(gè)。曲柄搖臂機(jī)構(gòu)被廣泛應(yīng)用在機(jī)械傳動(dòng)中。如何改進(jìn)工作效率和減少多余的功率損失直接地與滑移速度變化系數(shù)，搖臂的擺動(dòng)角度和曲柄搖臂的比率有關(guān)系。這些參數(shù)的合理組合采用對機(jī)械效率和產(chǎn)量有重要作用,這些主要體現(xiàn)在極小的傳輸角度上。認(rèn)識機(jī)械優(yōu)化傳動(dòng)目的是找到極小的傳輸角度的最大值。設(shè)計(jì)參數(shù)是適度地減少限制而且分開的合理優(yōu)化方法的結(jié)合。因此，完全限制領(lǐng)域的優(yōu)化傳動(dòng)建立了。以下步驟被采用在通常的設(shè)計(jì)方法。首先，測量出搖臂的長度l3和搖臂的擺動(dòng)角度的初始值。然后滑移速度變化系數(shù)K的值被定在允許的范圍內(nèi)。同時(shí)，曲柄固定的鉸接座標(biāo)A可能被認(rèn)為是任意值K。1.1 曲柄搖臂機(jī)構(gòu)桿的長度由圖Fig.1，左弧C2G是點(diǎn)A被允許的領(lǐng)域。點(diǎn) A的座標(biāo)的選擇從點(diǎn) C2到點(diǎn)。點(diǎn)A的座標(biāo)是yAyc2h0xAR2yA2

(1)(2)當(dāng)h0，高度，在range(0，H)被逐漸增加。如果選的越小,計(jì)算精度將越高。 R是設(shè)計(jì)圓的半徑。 d是從C2到G的距離。d l3cos 2Rcos( ) l3 cos (3)2 2 2計(jì)算弧AC1和AC2的長度，機(jī)械桿對應(yīng)于點(diǎn) A的長度是obtained[1,2]。1.2極小的傳動(dòng)角度極小的傳動(dòng)角度

minmin

(參見Fig.2)由equations[3]確定coscos

l22l32(l4l1)2min2l2l322(l42l2l3l1)max2l2l3

(4)(5)min 180 m ax (6)由于l1——曲柄的長度(毫米)l2——連桿的長度（毫米）l3——搖臂的長度（毫米）l4 ——機(jī)器的長度（毫米）首先,我們比較極小值 min 和 min 。并且我們記錄所有 min 的值大于或等于，然后選擇他們之間的最大值。第二,我們發(fā)現(xiàn)最大值min對應(yīng)于一個(gè)逐漸變小的范圍的任一個(gè)擺動(dòng)的角度(最大值

min

是不同于擺動(dòng)的角度和滑移速度變化系數(shù)

K)

。最后,

我們相似地慢慢縮小搖臂

l3

的長度。因而我們能獲得最大值

min

對應(yīng)于桿的不同長度,另外擺動(dòng)的角度

和滑移速度變化系數(shù)

K。Fig.3成功的表達(dá)設(shè)計(jì)的目的。它確定了無論是搖臂的長度

l3,最大值

min

出現(xiàn)的地點(diǎn)，只與搖臂的長度和機(jī)械的長度的比率 l3/l4有關(guān),當(dāng)確定l3時(shí)。設(shè)計(jì)方法2.1 認(rèn)識最優(yōu)傳動(dòng)設(shè)計(jì)下滑移速度變化系數(shù)和搖臂的最大擺動(dòng)的角度設(shè)計(jì)步驟如下。(1)根據(jù)所給的K和，通常采取對發(fā)現(xiàn)極限角度的解釋。桿的長度的對應(yīng)的比率l3/l4是從圖Fig.3獲得的。K1(7