《機(jī)械工程專業(yè)英語(yǔ)》測(cè)試題(157)含答案

《機(jī)械工程專業(yè)英語(yǔ)》測(cè)驗(yàn)題(15-17)一、 將以下詞組譯成漢語(yǔ)kinematicchain〔運(yùn)動(dòng)鏈〕skeletondiagram〔草圖，示意圖，簡(jiǎn)圖〕Gearsystem/Camsystem〔齒輪傳動(dòng)系統(tǒng)/凸輪系統(tǒng)〕uniformmotion/nonuniformmotion〔勻速運(yùn)動(dòng)/非勻速運(yùn)動(dòng)〕nonlinearmotion〔非線性運(yùn)動(dòng)〕kinematicanalysis〔運(yùn)動(dòng)分析〕schematicdiagram〔運(yùn)動(dòng)簡(jiǎn)圖〕textilemachinery〔紡織機(jī)械〕Kinematicdesign/kinematicsyntheses〔運(yùn)動(dòng)設(shè)計(jì)/運(yùn)動(dòng)合成〕machinedesign〔機(jī)械設(shè)計(jì)〕Geartrains/Cammechanisms〔輪系，齒輪傳動(dòng)鏈/凸輪機(jī)構(gòu)〕dynamicforce/inertiaforce/staticforce〔動(dòng)力/慣性力/靜力〕relativevelocity/absolutevelocity〔相對(duì)速度/確定速度〕angularacceleration/tangentialacceleration/centripetalacceleration/velocityvector〔角加速度/切向加速度/向心加速度/速度矢量〕binarylink/ternarylink〔二桿組/三桿組〕二、 將以下短語(yǔ)譯成漢語(yǔ)Planeandspatiallinkages〔平面和空間連桿〕constrainedkinematicchain/unconstrainedkinematicchain〔約束運(yùn)動(dòng)鏈/非約束運(yùn)動(dòng)鏈〕closed-looplinkage〔閉環(huán)運(yùn)動(dòng)鏈〕four-barlinkage〔四連桿機(jī)構(gòu)〕slider-crank(orcrankandslider)mechanism〔曲柄滑塊機(jī)構(gòu)〕internalcombustionengine〔內(nèi)燃機(jī)〕thekinematicanalysisofmechanisms〔機(jī)構(gòu)運(yùn)動(dòng)分析〕degreeoffreedomofthemechanism〔機(jī)構(gòu)自由度〕kinematicanalysisprocess/kinematicsynthesisprocess〔運(yùn)動(dòng)分析步驟/運(yùn)動(dòng)合成步驟〕inputangularvelocity〔輸入角速度〕inputangularacceleration〔輸入角加速度〕automaticpackagingmachinery〔自動(dòng)包裝機(jī)〕cam-contourdimensions/cam-followerdiameters〔凸輪輪廓尺寸/凸輪從動(dòng)件直徑〕mechanicalanalogcomputer〔機(jī)構(gòu)模擬計(jì)算機(jī)〕dead-centerposition〔死點(diǎn)位置〕crank-rockerlinkage/double-rockerlinkage/double-crank(drag-link)linkage〔曲柄搖桿機(jī)構(gòu)/雙搖桿機(jī)構(gòu)/雙曲柄機(jī)構(gòu)〕maximumforcecomponent/resultingoutputforceortorque〔最大的力氣組成/輸出的最大力或力矩〕outputmotionvariables/inputmotionvariable〔輸出運(yùn)動(dòng)變量/輸入運(yùn)動(dòng)變量〕absoluteangularpositions〔確定角位置〕velocitypolygonmethod〔速度的多邊形的方法〕instantaneouscentermethod/instantcentermethod〔瞬心法/即時(shí)瞬心法〕inertia-forceanalysisofmechanismsandmachines〔機(jī)構(gòu)和機(jī)器的慣性力分析〕oneandthesamecoordinatesystem/inertiaframeofreference〔慣性參考系〕systematicdesignofmechanisms〔機(jī)械設(shè)計(jì)的系統(tǒng)〕cam-contourdimensions/cam-followerdiameters〔凸輪輪廓尺寸/凸輪從動(dòng)件直徑〕三、 將以下單詞譯成漢語(yǔ)Mechanism〔機(jī)械，機(jī)構(gòu)，機(jī)構(gòu)學(xué)〕configuration〔外形，構(gòu)造，構(gòu)造〕displacement〔位移〕velocity〔速度〕acceleration〔加速度〕gear〔齒輪〕sprocket〔鏈輪〕pulley〔帶輪〕kinematician/dynamics〔運(yùn)動(dòng)/動(dòng)力學(xué)，力學(xué)〕kinematician〔運(yùn)動(dòng)〕四．翻譯以下句子Thesimplestclosed-looplinkageisthefour-barlinkage,whichhasthreemovinglinks(plusonefixedlink)andfourpinjoints.〔最簡(jiǎn)潔的封閉式的連桿機(jī)構(gòu)就是四桿機(jī)構(gòu)，四桿機(jī)構(gòu)有三個(gè)運(yùn)動(dòng)構(gòu)件〔加上一個(gè)固定構(gòu)件〕并且有四個(gè)銷軸?！矨lthoughthefour-barlinkageandslider-crankmechanismareveryusefulandfoundinthousandsofapplications,wecanseethattheselinkageshavelimitedperformancelevel.(雖然四桿機(jī)構(gòu)和曲柄滑塊機(jī)構(gòu)是格外有用而且在成千上萬(wàn)的應(yīng)用中都可找到。但是我們還看到，這些連桿機(jī)構(gòu)其性能水平的發(fā)揮已經(jīng)受到限制。)Theprocessofdrawingkinematicdiagramsanddeterminingdegreesoffreedomofmechanismsarethefirststepsinboththekinematicanalysisandsynthesisprocess.〔畫(huà)運(yùn)動(dòng)圖和確定機(jī)構(gòu)自由度的過(guò)程，就是運(yùn)動(dòng)分析和綜合過(guò)程的第一個(gè)階段?！砊heabilitytovisualizerelativemotion,toreasonwhyamechanismisdesignedthewayitis,andtheabilitytoimproveonaparticulardesignaremarksofasuccessfulkinematician.〔設(shè)想相對(duì)運(yùn)動(dòng)的力氣，能推想出之所以這樣設(shè)計(jì)一個(gè)機(jī)構(gòu)的緣由和對(duì)一個(gè)具體設(shè)計(jì)進(jìn)展改進(jìn)的力氣是一個(gè)成功的機(jī)構(gòu)學(xué)家的標(biāo)志?！矺inematicinversionistheprocessoffixingdifferentlinksofachaintocreatedifferentmechanisms〔這個(gè)過(guò)程的動(dòng)態(tài)反演是固定的,不同的連接制造出不同的機(jī)制?！砊herearethreecustomarytasksforkinematicsynthesis:functiongeneration,pathgenerationandmotiongeneration.〔對(duì)于運(yùn)功的綜合，慣例上有三個(gè)任務(wù):函數(shù)的生成、軌跡生成和運(yùn)動(dòng)生成?！澄澹g以下短文1.Akinematicchainisasystemoflinks,thatis,rigidbodies,whichareeitherjointedtogetherorareincontactwithoneanotherinamannerthatpermitsthemtomoverelativetooneanother.Ifoneofthelinksisfixedandthemovementofanyotherlinktoanewpositionwillcauseeachoftheotherlinkstomovetodefinitepredictableposition,thesystemisaconstrainedkinematicchain.Ifoneofthelinksisheldfixedandthemovementofanyotherlinktoanewpositionwillnotcauseeachoftheotherlinksto movetoadefinitepredictableposition,thenthesystemisanunconstrainedkinematicchain.〔運(yùn)動(dòng)鏈?zhǔn)且粋€(gè)構(gòu)件系統(tǒng)裝置即假設(shè)干個(gè)剛體，它們或者彼此鉸接或者相互接觸，方式上是允許它們彼此間產(chǎn)生相對(duì)運(yùn)動(dòng)。假設(shè)構(gòu)件中的某一構(gòu)件被固定而使任何其他一個(gè)構(gòu)件運(yùn)動(dòng)到的位置將會(huì)引起其他各個(gè)構(gòu)件也運(yùn)動(dòng)到確定的預(yù)期的位置上的話，該系統(tǒng)裝置就是一個(gè)可約束的運(yùn)動(dòng)鏈。假設(shè)構(gòu)件中的某一構(gòu)件仍保持固定而使任一運(yùn)動(dòng)到達(dá)一的位置而不會(huì)使其他各個(gè)構(gòu)件運(yùn)動(dòng)到一個(gè)確定的預(yù)期的位置上的話，則該系統(tǒng)裝置是一個(gè)非約束運(yùn)動(dòng)鏈?！矨mechanismorlinkageisaconstrainedkinematicchain,andisamechanicaldevicethathasthepurposeoftransferringmotionand/orforcefromasourcetoanoutput.Alinkageconsistsoflinks(orbars),generallyconsideredrigid,whichareconnectedbyjoints,suchaspin(orrevolute)orprismaticjoints,toformopenorclosedchains(orloops).Suchkinematicchains,withatleastonelinkfixed,become(1)mechanismsifatleasttwootherlinksremainmobility,or(2)structuresifnomobilityremains.Inotherwords,amechanismpermitsrelativemotionbetweenits“rigidlinks“;astructuredoesnot.Sincelinkagesmakesimplemechanismsandcanbedesignedtoperformcomplextasks,suchasnonlinearmotionandforcetransmission,theywillreceivemuchattentioninmechanismstudy.〔機(jī)構(gòu)或連桿構(gòu)件是一個(gè)可約束的傳動(dòng)鏈而且是一個(gè)從輸入到輸出以傳遞運(yùn)動(dòng)和〔或〕力為目的的機(jī)械裝置。連桿機(jī)構(gòu)是由通常被認(rèn)為是剛體構(gòu)件或桿組成的，它們是以銷軸鉸接的，例如用柱銷〔圓形的〕或棱柱體銷軸鉸接，以便成形開(kāi)式或閉式〔回環(huán)式〕的運(yùn)動(dòng)鏈。這樣的運(yùn)動(dòng)鏈在至少有一個(gè)構(gòu)件被固定的條件下：〔1〕假設(shè)至少有兩個(gè)構(gòu)件能保持運(yùn)動(dòng)，就變?yōu)闄C(jī)構(gòu)，〔2〕假設(shè)沒(méi)有一個(gè)構(gòu)件能夠運(yùn)動(dòng)，則就成為構(gòu)造。換句話說(shuō)，機(jī)構(gòu)是允許其“剛性構(gòu)件”之間相對(duì)運(yùn)動(dòng)，而構(gòu)造則不能。由于連桿機(jī)構(gòu)做成一簡(jiǎn)潔機(jī)構(gòu)而且能設(shè)定實(shí)現(xiàn)簡(jiǎn)潔的任務(wù)，例如非線性運(yùn)動(dòng)和力的傳遞運(yùn)動(dòng)。它們?cè)跈C(jī)構(gòu)學(xué)爭(zhēng)論中將受到更多的關(guān)注?！砊hefour-barlinkagemaytakeformofaso-calledcrank-rockeroradouble-rockeroradouble-crank(drag-link)linkage,dependingontherangeofmotionofthetwolinksconnectedtothegroundlink.Theinputcrankofacrank-rockertypecanrotatecontinuouslythrough360,while theoutputlinkjust“rocks“(oroscillates).Asaparticularcase, inaparallelogramlinkage,wherethelengthoftheinputlinkequalsthatoftheoutputlinkandthelengthsofthecouplerandthegroundlinkarealsothesame,boththeinputand output link may rotate entirely around or switch into a crossed configuration called anantiparallelogramlinkage.[1]Grashof”scriteriastates thatthesumofthe shortestandlongestlinksofaplanarfour-barlinkagecannotbegreaterthanthesumoftheremainingtwolinksifthereistobecontinuousrelativerotationbetweenanytwolinks.〔四桿機(jī)構(gòu)可具有一種稱作曲柄搖桿機(jī)構(gòu)的形式，一種雙搖桿機(jī)構(gòu)，一種雙曲柄〔拉桿〕機(jī)構(gòu)，致于稱作哪一種形式的機(jī)構(gòu)，取決于跟機(jī)架〔固定構(gòu)件〕相連接的兩桿的運(yùn)動(dòng)范圍。曲柄搖桿機(jī)構(gòu)的輸入構(gòu)件，曲柄可旋轉(zhuǎn)通過(guò)360°并連續(xù)轉(zhuǎn)動(dòng)，而輸出構(gòu)件僅僅作搖動(dòng)〔即搖擺的桿件〕。作為一個(gè)特例，在平行四桿機(jī)構(gòu)中，輸入桿的長(zhǎng)度等于輸出桿的長(zhǎng)度，連接桿的長(zhǎng)度和固定桿〔機(jī)架〕的長(zhǎng)度，也是相等的。其輸入和輸出都可以作整周轉(zhuǎn)動(dòng)或者轉(zhuǎn)換成稱作反平行四邊形機(jī)構(gòu)的穿插構(gòu)造。格拉肖夫準(zhǔn)則〔定理〕說(shuō)明：假設(shè)四桿機(jī)構(gòu)中，任意兩桿之間能作連續(xù)相對(duì)轉(zhuǎn)動(dòng)，那么，其最長(zhǎng)桿長(zhǎng)度與最短桿長(zhǎng)度之和就小于或等于其余兩桿長(zhǎng)度之和?！矪esideshavingknowledgeoftheextentoftherotationsofthelinks,itwouldbeusefultohaveameasureofhowwellamechanismmight“run“beforeactuallybuildingit.Hartenbergmentionsthat“run“isatermthatmeanseffectivenesswithwhichmotionisimpartedtotheoutputlink;itimpliessmoothoperation,inwhichamaximumforcecomponentisavailabletoproduceaforceortorqueinanoutputmember.Althoughtheresultingoutputforceortorqueisnotonlyafunctionofthegeometryofthelinkage,butisgenerallytheresultofdynamicorinertiaforce,whichareoftenseveraltimesaslargeasthestaticforce.Fortheanalysisoflow-speedoperationsorforaneasilyobtainableindexofhowanymechanismmightrun,theconceptofthetransmissionangleisextremelyuseful.Duringthemotionofamechanism,thetransmissionanglechangesinvalue.Atransmissionangleof0degreemayoccurataspecificposition,onwhichtheoutputlinkwillnotmoveregardlessofhowlargeaforceisappliedtotheinputlink.Infact,duetofrictioninthejoints,thegeneralruleofthumb,istodesignmechanismswithtransmissionangleoflargerthanaspecifiedvalue.Matrix-baseddefinitionshavebeendevelopedwhichmeasuretheabilityofalinkagetotransmitmotion.Thevalueofadeterminant(whichcontainsderivativesofoutputmotionvariableswithrespecttoaninputmotionvariableforagivenlinkagegeometry[2])isameasureofthemovabilityofthelinkageinaparticularposition.〔除了具備關(guān)于構(gòu)件回轉(zhuǎn)范圍的學(xué)問(wèn)之外，還要具備如何使機(jī)構(gòu)在制造之前就能“運(yùn)轉(zhuǎn)”的良好措施，那將是很有用的。哈登伯格〔Hartenberg〕說(shuō)到：“運(yùn)轉(zhuǎn)”是一個(gè)術(shù)語(yǔ)，其意義是傳給輸出構(gòu)件的運(yùn)動(dòng)的有效性。它意味著運(yùn)轉(zhuǎn)平穩(wěn)，其中能在輸出構(gòu)件中產(chǎn)生一個(gè)力或扭矩的最大分力是有效的。雖然最終的輸出力或扭矩不僅是連桿幾何圖形的函數(shù)，而且一般也是動(dòng)力或慣性力的結(jié)果，那常常是大到如靜態(tài)力的幾倍。為了分析低速運(yùn)轉(zhuǎn)或?yàn)榱艘子讷@得如何能使任一機(jī)構(gòu)“運(yùn)轉(zhuǎn)”的指數(shù)，傳動(dòng)角的概念是格外有用的。在機(jī)構(gòu)運(yùn)動(dòng)期間，傳動(dòng)角的值在轉(zhuǎn)變。傳動(dòng)角0°可發(fā)生在特別位置上。在此特別位置上輸出桿將不運(yùn)動(dòng)而與施加到輸入桿上的力多大無(wú)關(guān)。事實(shí)上，由于運(yùn)動(dòng)副摩擦的影響，一般依據(jù)實(shí)際閱歷，用比規(guī)定值大的傳動(dòng)角去設(shè)計(jì)機(jī)構(gòu)。衡量連桿機(jī)構(gòu)傳遞運(yùn)動(dòng)力氣的矩陣根底的定義已經(jīng)爭(zhēng)論出來(lái)。一個(gè)打算性因素的值〔它含有對(duì)于某個(gè)給定機(jī)構(gòu)圖形，位置的輸出運(yùn)動(dòng)變量對(duì)輸入變量的導(dǎo)數(shù)〕是該連桿機(jī)構(gòu)在具體位置中的可動(dòng)性的一個(gè)尺度?！矼echanismsformthebasicgeometricalelementsofmanymechanicaldevicesincludingautomaticpackagingmachinery,typewriters,mechanicaltoys,textilemachinery,andothers.Amechanismtypicallyisdesignedtocreateadesiredmotionofarigidbodyrelativetoareferencemember.Kinematicdesign,orkinematicsyntheses,ofmechanismsoftenisthefirststepinthedesignofacompletemachine.Whenforcesareconsidered,theadditionalproblemsofdynamics,bearingloads,stresses,lubrication,andthelikeareintroduced,andthelargerproblembecomesoneofmachinedesign.〔機(jī)構(gòu)是形成很多機(jī)械裝置的根本幾何構(gòu)造單元，這些機(jī)械裝置包括自動(dòng)包裝機(jī)、打印機(jī)、機(jī)械玩具、紡織機(jī)械和其他機(jī)械等。典型的機(jī)構(gòu)要設(shè)計(jì)成使剛性構(gòu)件相對(duì)基準(zhǔn)構(gòu)件產(chǎn)生所期望的運(yùn)動(dòng)。機(jī)構(gòu)的運(yùn)動(dòng)設(shè)計(jì)即運(yùn)動(dòng)的綜合，第一步常常是先設(shè)計(jì)整部機(jī)器。當(dāng)考慮受力時(shí)，要提出動(dòng)力學(xué)方面的問(wèn)題，軸承的荷載、應(yīng)力、潤(rùn)滑等類似的問(wèn)題，而較大的問(wèn)題是機(jī)器構(gòu)造問(wèn)題?！矨kinematiciandefinedkinematicsas“thestudyofthemotionofmechanismsandmethodsofcreatingthem.“Thefirstpartofthisdefinitiondealswithkinematicanalysis.Givenacertainmechanism,themotioncharacteristicsofitscomponentswillbedeterminedbykinematicanalysis.Thestatementofthetasksofanalysiscontainsallprincipaldimensionsofthemechanism,theinterconnectionsofitslinks,andthespecificationoftheinputmotionormethodofactuation.Theobjectiveistofindthedisplacements,velocities,accelerations,shockorjerk(secondacceleration),andperhapshigheraccelerationsofthevariousmembers,aswellasthepathsdescribedandmotionsperformedbycertainelements.Inshort,inkinematicanalysiswedeterminetheperformanceofagivenmechanism.Thesecondpartofdefinitionmaybeparaphrasedintwoways:〔運(yùn)動(dòng)學(xué)家把運(yùn)動(dòng)學(xué)定義為“爭(zhēng)論機(jī)構(gòu)的運(yùn)動(dòng)和創(chuàng)立機(jī)構(gòu)的方法”。這個(gè)定義的第一局部就涉及運(yùn)動(dòng)學(xué)分析。一個(gè)機(jī)構(gòu)，其構(gòu)成的運(yùn)動(dòng)特性將由運(yùn)動(dòng)學(xué)分析來(lái)確定。表達(dá)運(yùn)動(dòng)分析的任務(wù)包含機(jī)構(gòu)的主要尺寸、〔二次加速度〕，和可能發(fā)生的各構(gòu)件的高階加速度以及所描述徑跡和由某些構(gòu)件來(lái)實(shí)現(xiàn)的運(yùn)動(dòng)。定義的其次局部可用以下兩方面來(lái)解釋：〕ThestudyofmethodsofcreatingagivenmotionbymeansofmechanismsThestudyofmethodsofcreatingmechanismshavingagivenmotion.Ineitherversion,themotionisgivenandthemechanismistobefound.Thisistheessenceofkinematicsynthesis.Thuskinematicsynthesisdealswiththesystematicdesignofmechanismsforagivenperformance.Theareaofsynthesismaybegroupedintotwocategories.爭(zhēng)論借助機(jī)構(gòu)來(lái)產(chǎn)生給定運(yùn)動(dòng)的方法爭(zhēng)論建筑能產(chǎn)生給定運(yùn)動(dòng)機(jī)構(gòu)的方法在兩個(gè)方案中，運(yùn)動(dòng)是給定的而機(jī)構(gòu)是創(chuàng)立的。這就是運(yùn)動(dòng)綜合的本質(zhì)。這樣運(yùn)動(dòng)綜合涉及到為給定性能的機(jī)構(gòu)的系統(tǒng)設(shè)計(jì)。運(yùn)動(dòng)綜合方面又可歸結(jié)為以下兩類Typesynthesis.Giventherequiredperformance,whattypeof mechani