機(jī)電專業(yè)英語第2版2Unit 2 Machine Elements機(jī)械零件-席東河-機(jī)電專業(yè)英語

MachineElementsUnit2機(jī)械零件TestingBeforeClass：Whatdoes“clutch”mean(radio)？MachineElementsCouplingsCrankshaftsandConnectingrodsMachineToolClutchBearingsMachineElements

TranslationReadingMoreTranslatingSkillsTextHoweversimple,anymachineisacombinationofindividualcomponentsgenerallyreferredtoasmachineelementsorparts.Thus,ifamachineiscompletelydismantled,acollectionofsimplepartsremainssuchasnuts,bolts,springsgears,camsandshafts—thebuildingblockofallmachinery1.Amachineelementis,therefore,asingleunitdesignedtoperformaspecificfunctionandcapableofcombiningwithotherelements.Sometimescertainelementsareassociatedinpairs2,suchasnutsandboltsorkeysandshafts.Inotherinstance,agroupofelementsiscombinedtoformasubassembly,suchasbearings,couplings,andclutches.Themostcommonexampleofamachineelementisagear,which,fundamentally,isacombinationofthewheelandthelevertoformatoothedwheel.Therotationofthisgearonahuborshaftdrivesothergearsthatmayrotatefasterorslower,dependinguponthenumberofteethonthebasicwheels.Otherfundamentalmachineelementshaveevolvedfromwheelandlever.Awheelmusthaveashaftonwhichitmayrotate.Thewheelisfastenedtotheshaftswithcouplings.Theshaftmustrestinbearings,maybeturnedbyapulleywithabeltorachainconnectingittoapulleyonasecondshaft.Thesupportingstructuremaybeassembledwithboltsorrivetsorbywelding4.Properapplicationofthesemachineelementsdependsuponknowledgeoftheforceonthestructureandthestrengthofthematerialsemployed.Theindividualreliabilityofmachineelementsbecomesthebasisforestimatingtheoveralllifeexpectancyofacompletemachine.Manymachineelementsarethoroughlystandardized.Testingandpracticalexperiencehaveestablishedthemostsuitabledimensionsforcommonstructuralandmechanicalparts.Throughstandardization,uniformityofpracticeandresultingeconomicsareobtained.Notallmachinepartsinusearestandardized,however.Intheautomotiveindustryonlyfasteners,bearings,bushings,chains,andbeltsarestandardized.Cbination[kCmbi5neiFEn]n.組合，結(jié)合individual[indi5vidjuEl]adj.單獨(dú)的，各個(gè)的，個(gè)別的，特殊的component[kEm5pEunEnt]n.元件，構(gòu)件，部件dismantle[dis5mAntl]vt.分解（機(jī)器），拆開，拆卸assemble[E5sembl]v.安裝，裝配，組合；集合，集中n組件nut[nQt]n.螺母；難對(duì)付的人；難解的問題；堅(jiān)果vi.采堅(jiān)果bolt[bEult]n.螺栓；（門、窗等的）插銷gear[giE]n.儀器，裝置；傳動(dòng)裝置，齒輪cam[kAm]n.凸輪，偏心輪；樣板，靠模，仿形板lever[5li:vE]n.杠桿，控制桿，操作桿shaft[FB:ft]n.柱身；連桿；傳動(dòng)軸，旋轉(zhuǎn)軸；軸machinery[mE5Fi:nEri]n.機(jī)器(總稱)associate[E5sEuFieit]v.聯(lián)合，結(jié)合，參加，連帶key[ki:]n.鍵，電鍵，開關(guān)；楔，銷；鑰匙subassembly[7sQbE5sembli]n.組合件，部件，機(jī)組coupling[5kQpliN]n.聯(lián)軸節(jié)，聯(lián)軸器；聯(lián)結(jié)器，聯(lián)合器clutch[klQtF]n.離合器，聯(lián)軸器；夾緊裝置fundamentally[fQndE5mentli]adv.（從）根本上hub[hQb]n.(輪)轂；中心；木片rotate[rEu5teit]n.(使某物)旋轉(zhuǎn)或轉(zhuǎn)動(dòng)evolve[i5vClv]v.進(jìn)化，演變；開展，發(fā)展，展開pulley[5puli]n.滑輪（組）；滑車；皮帶輪rivet[5rivit]n.鉚釘v鉚接，鉚weld[weld]v.&n.焊接，熔焊reliability[rilBiE5biliti]n.可靠性，安全性，準(zhǔn)確性thoroughly[5WQrEli]adv.完全地，充分地，徹底地standardize[5stAndEdBiz]vt.標(biāo)準(zhǔn)化，統(tǒng)一標(biāo)準(zhǔn)；標(biāo)定，校準(zhǔn)establish[is5tAbliF]vt.確定，制定；建立，創(chuàng)辦，產(chǎn)生；使固定dimension[di5menFEn]n.尺寸，尺度；范圍，方面bushing[5buFiN]n.襯套；軸襯；軸瓦；[電]（絕緣）套管uniformity[7mju:ni5fC:miti]n.均勻性，一致性automotive[C:tE5mEutiv]adj.自動(dòng)的，自動(dòng)車的crank[krANk]n.曲軸refertoas稱為，叫做；當(dāng)做；參考作為；所說的；提到的1.Thus,ifamachineiscompletelydismantled,acollectionofsimplepartsremainssuchasnuts,bolts,springsgears,camsandshafts—thebuildingblockofallmachinery.

譯文：因此，如果把機(jī)床完全拆開，就可以得到像螺母、螺栓、彈簧、齒輪、凸輪及軸等簡(jiǎn)單零件——所有機(jī)器的標(biāo)準(zhǔn)元件。2.Sometimescertainelementsareassociatedinpairs.譯文：某些特定的元件必須成對(duì)地工作。說明：beassociatedwith：與……有關(guān)；涉及又如：Iassociatedwithhiminbusiness.我與他和伙經(jīng)商。Theseconcernsmaybeassociatedwithstrongfeelingssuchasangerorshame.這些憂慮很可能與惱火、羞愧之類的強(qiáng)烈情緒有關(guān)聯(lián)。3.Themostcommonexampleofamachineisagear,which,fundamentally,isacombinationofthewheelandthelevertoformatoothedwheel.譯文：機(jī)器零件中最常用的是齒輪，它實(shí)際上是由輪子和桿組成的帶有齒的輪子。說明：Which引導(dǎo)非限定性定語從句，修飾gear，不定式toformatoothedwheel作結(jié)果狀語。4．Thesupportingstructuremaybeassembledwithboltsorrivetsorbywelding.譯文：支撐結(jié)構(gòu)可由螺栓或鉚釘或通過焊接固定在一起。說明：句中withboltsorrivetsorbywelding作方式狀語，beassembledwith用……安裝，又如：Thebookcasecaneasilybeassembledwithascrewdriver.這書柜用一把螺絲刀就可以很容易地安裝起來。

I.Answerthefollowingquestions.

Whatisreferredtoasamachineelement?Whichisthemostcommonmachineelement?2.Whatareotherfundamentalmachineelements?3.Whichmachineelementsarestandardizedintheautomotiveindustry?Amachineelementisasingleunitdesignedtoperformaspecificfunctionandcapableofcombiningwithotherelements.Themostcommonmachineelementisagear.Otherfundamentalmachineelementshaveevolvedfromwheelandlever.Intheautomotiveindustryonlyfasteners,bearings,bushings,chains,andbeltsarestandardized.keykeykeyII.Placea“T”(true)oran“F”(false)besidethesentencesaccordingtothetext.T1.Gearsareusedasbuildingblocksfortheconstructionofmostdevices,apparatus,andmachinery.2.Apairofgearswithdifferentnumbersofteethwillrotateatdifferentspeeds.3.Spurgearsandbevelgearsaredifferentintheirapplicationsbecausetheirshapesaredifferent.4.Themostcommonmachineelementisthegearfromwhichotherfundamentalmachineelementshavedeveloped.5.Acouplingisamachineelement,whichjoinstwoshafts.6.Allmachinepartshavebeendevelopedintostandardizeddesigns.FTTTFkeykeykeykeykeykeyⅢ．TranslatethefollowingsentencesintoChinese．Themostcommonmachineelementisthegear,whichcombinesthefeatureofthewheelandthelevertoformatoothedwheel.

2.Thehardnessofageardeterminesitsabilitytoresistwear.最常見的機(jī)械零件是齒輪，實(shí)際上是由輪子和桿組成的跌有齒的輪子。齒輪的堅(jiān)硬性決定了它的耐磨能力。keykeyⅢ．TranslatethefollowingsentencesintoChinese．3.Manufacturingengineershavecenteredtheireffortsonthedevelopmentofstandardizedelements.4.Thesepartsareproducedinlargequantitieswithahighdegreeofperfectionatreducedcost.制造業(yè)的工程師們集中精力，研制標(biāo)準(zhǔn)化的零件。這些零件是以大批量、高規(guī)格和降低成本的條件下生產(chǎn)的。keykey 英漢兩種語言都有一詞多類、一詞多義的現(xiàn)象。一詞多類是指一個(gè)詞往往屬于多個(gè)詞類，具有幾種不同的意義。如display一詞，既可做名詞“顯示（器）”，又可以作形容詞“展覽的、陳列用的”，還可做動(dòng)詞“顯示、表現(xiàn)”等意思。一詞多義是說同一個(gè)詞類中，往往有幾個(gè)不同的詞義。如power一詞，做名詞時(shí)，其漢語意思為“電力、功率、次方”等。在英漢翻譯過程中，我們?cè)谂寰渥咏Y(jié)構(gòu)后就要善于選擇和確定句子中關(guān)鍵詞的意義。選擇和確定詞義通常從以下幾個(gè)方面入手：

詞義的確定一、根據(jù)詞類確定詞義

選擇某個(gè)詞的詞義時(shí)，首先要確定這個(gè)詞在句中應(yīng)屬于哪一種詞類，然后再進(jìn)一步確定其詞義。下面以display為例：Here,youhavetheoptionofdefiningyourowndisplayvariants.這里，你有權(quán)定義你自己的顯示變式。（display為名詞）Often,itisbesttodisplaymaterialsonaninformationtable.通常，最好是把資料放在提供各類資訊的桌子上展示。(display為動(dòng)詞)

Thereversesideofacontrolpanel,displaypanel,orthelike;thesidewiththeinterconnectingwiring.（display為形容詞）控制面板、顯示面板或類似的面板的反面，即帶有互連接線的那一面。二、同一詞類表達(dá)不同詞義

英語中同一個(gè)詞，同一類詞，在不同的場(chǎng)合，往往具有不同的含義。此時(shí)，必須根據(jù)上下文的聯(lián)系及整個(gè)句子的意思加以判斷和翻譯。例如as這一連詞：Wearresistanceimprovesascuttingtoolhardnessincrease.當(dāng)切削刀具的硬度越高時(shí)，其耐磨性就越好。（as引導(dǎo)時(shí)間狀語從句）Asheatmakesthingsmove,itisaformofenergy.因?yàn)闊崮苁刮矬w運(yùn)動(dòng)，所以熱是能的一種形式。（as引導(dǎo)原因狀語從句）三、根據(jù)單詞搭配情況確定詞義英譯漢時(shí)，不僅必須根據(jù)上下文的聯(lián)系理解詞義，還需要根據(jù)詞的搭配情況來理解詞義。尤其在科技文獻(xiàn)中，由于學(xué)科及專業(yè)不同，同一個(gè)詞在不同的專業(yè)中具有不同的意義。比如：

Thefifthpoweroftwoisthirty-two.二的五次方是三十二。（數(shù)學(xué)）

Withthedevelopmentofelectricalengineering,powercanbetransmittedoverlongdistances.隨著電氣工程的發(fā)展,電力能輸送得非常遠(yuǎn)。（電學(xué)）

Frictioncancausealossofpowerineverymachine.摩擦能引起每一臺(tái)機(jī)器功率的損耗。（物理學(xué)）四、根據(jù)名詞的單復(fù)數(shù)選擇詞義英語中有些名詞的單數(shù)或復(fù)數(shù)表達(dá)的詞義完全不同。例如：名詞 單數(shù)詞義 復(fù)數(shù)詞義facility 簡(jiǎn)易，靈巧 設(shè)施，工具charge 負(fù)荷，電荷 費(fèi)用spirit 精神 酒精Althoughtheylost,theteamplayedwithtremendousspirit.那隊(duì)輸是輸了，但卻表現(xiàn)了極其頑強(qiáng)的精神。Whisky,brandy,ginandrumareallspirits.威士忌、白蘭地、杜松子酒和朗姆酒都是烈酒。

CuttingTools

CuttingTools

Metalcuttingtoolsmustpossessavarietyofdifferentpropertiesinordertocutthedifferentmetalsundervaryingconditionsofseverity.Tomeetthesedemands,toolshavebeenproducedfromavarietyofmaterials.

PropertiesofCuttingToolsThemostimportantpropertiesofcuttingtoolsarehardnessathightemperature,wearresistance,andimpactstrength.切削刀具金屬切削刀具必須具有許多不同的性能，才能在各種惡劣條件下切削不同的金屬。為滿足這些要求，制作刀具需要用許多種材料。切削刀具的性能切削刀具最重要的性能是在高溫下能保持的硬度以及耐磨損耐沖擊和韌性好。Asatoolcuts,highheatisdevelopedasaresultofcompressionandfrictionatthecuttingedgeofthetool.Allmetalcuttingtoolsbegintolosehardnesswhenheatedtosufficientlyhightemperatures.Asthetoolsoftensduetoheat,itwearsandbreaksdownatthecuttingedgeorface.Variouscuttingtoolmaterialsbegintolosetheirhardnessatdifferenttemperatures.Hence,thehardnessofthetoolandthedegreetowhichitremainsitshardnessathightemperatureareimportantintheselectionofacutting-toolmaterial.

當(dāng)?shù)毒哌M(jìn)行切削時(shí)，刀具刃口處的壓力和摩擦產(chǎn)生了高溫。達(dá)到一定高的溫度時(shí)，所有的金屬切削刀具便開始軟化。在刀口因高溫而軟化的同時(shí)，刀具刃口便開始磨耗并損壞。不同的切削刀具材料在不同的溫度點(diǎn)開始軟化。因此，刀具的硬度和它在高溫下所能保持的硬度是選擇切削刀具材料時(shí)的重要因素。Acuttingtooliswear-resistantifitresistsabrasionatthecuttingedgeandalongthetoolface.Wearresistanceimprovesascuttingtoolhardnessincreases.Cuttingtoolsmustalsohavehighstrengthinordertobevibrationandimpact-resistant.Strengthincutting-toolmaterialisnotalwaysproportionaltohardness.Someofthehardesttoolmaterialslackstrengthbecausetheyaretoobrittle.如果切削刀具的刃口和刀面耐磨，刀具就不易磨損。切削刀具的硬度越高，耐磨性就越好。切削刀具還必須具有高強(qiáng)度才能抗振動(dòng)和抗沖擊。切削刀具材料的強(qiáng)度并不都是與硬度成正比的。有些硬的刀具材料由于太脆而缺乏強(qiáng)度。MaterialsUsedinCuttingToolsThevariousmaterialsfromwhichmostmetalcuttingtoolsaremadecanbeclassifiedunderthefollowingprincipalheadings:?Carbontoolsteel?High-speedsteel?Castalloys?Cementedcarbides?Ceramics?Diamonds大多數(shù)金屑切削刀具的制作材料可分為以下幾大類：碳素刀具鋼；高速鋼；鑄合金；硬質(zhì)合金；陶瓷；金剛石。Toollife,orthenumberofpartsproducedbyacutting-tooledgebeforeregrindingisrequired,isaveryimportantcostfactorinmanufacturingapartorproduct.Cuttingtoolsmustberegroundatthefirstsignofdullness.Ifatoolisusedbeyondthispoint,itwillbreakdownrapidly.

刀具壽命，即切削刀刃在需要重新打磨之前能加工的零件數(shù)，是生產(chǎn)某個(gè)零件或產(chǎn)品的重要成本因素。當(dāng)切削刀具開始變鈍時(shí)必須重新打磨。如果在這時(shí)還要繼續(xù)用下去，刀具會(huì)很快地磨損。Inordertodetectthetimewhenacuttingtoolshouldbechanged,mostmodernmachinesareequippedwithindicatorsthatshowthehorsepowerusedduringthemachiningoperation.Whenatoolbecomesdull,morehorsepowerisrequiredfortheoperation,whichwillshowontheindicator.Whenthisoccurs,thetoolshouldberegroundimmediately.要知道什么時(shí)候該換刀具，大部分現(xiàn)代機(jī)床都安裝了指示器來顯示切削加工所耗的功率。當(dāng)?shù)毒哂免g時(shí)，加工需要消耗更多的功率，并由指示器顯示出來。一旦發(fā)生這種情況就應(yīng)當(dāng)立即打磨刀具。variety[v?'rai?ti]n.多樣；種類；雜耍[復(fù)數(shù)varieties]property['prCp?ti]n.性質(zhì)，性能；財(cái)產(chǎn)；所有權(quán)severity[si'veriti]n.嚴(yán)重；嚴(yán)格；猛烈[復(fù)數(shù)severities]wear[wε?]n.穿著，磨損，耐久性v.穿著，用舊，耗損impact['imp?kt,

im'p?kt]vt.影響；撞擊；沖突vi.沖擊n.效果；碰撞；compression[k?m'preF?n]n.壓縮，濃縮；壓榨，壓迫abrasion[?'brei?n]n.磨損；磨耗；擦傷friction['frikF?n]n.摩擦，摩擦力hence[hens]adv.因此；今后proportional[pr?u'pC:F?n?l]adj.比例的，成比例的；相稱的n.比例項(xiàng)brittle['britl]adj.易碎的，脆弱的；易生氣的(brittler,brittlest)carbon['kɑ:b?n]n.碳；碳棒；復(fù)寫紙adj.碳的；碳處理的cast[kɑ:s,k?st]vt.投，拋；計(jì)算；澆鑄；投射n.投擲；鑄件；鑄型cement[si'ment]vt.鞏固，加強(qiáng)；接合vi.粘牢n.水泥；接合劑carbide['kɑ:baid]n.【化學(xué)】碳化物；碳化鈣regrind[ri:'ɡraind]vt.再磨研，重研磨，再磨dullness['dQlnis]n.遲鈍，鈍度recondition[,ri:k?n'diF?n]vt.修理，修復(fù)；重建；更新avarietyof種種；各種各樣的impacton影響；對(duì)……沖擊，碰撞1.Whatarethemostimportantpropertiesofcuttingtools?2.Whichfactorsareimportantintheselectionofacutting-toolmaterial?Why?I．Answerthefollowingquestionsaccordingtothereading．Themostimportantpropertiesofcuttingtoolsarehardnessathightemperature,wearresistance,andimpactstrength.Thehardnessofthetoolandthedegreetowhichitremainsitshardnessathightemperatureareimportantintheselectionofacutting-toolmaterial.Becauseallmetalcuttingtoolsbegintolosehardnesswhenheatedtosufficientlyhightemperatures.keykey3.Howmanysortsareclassifiedinthevariousmaterialsfromwhichmostmetalcuttingtoolsaremade?4.Whyaremostmodernmachinesequippedwithindicatorsthatshowthehorsepowerusedduringthernachiningoperation?I．Answerthefollowingquestionsaccordingtothereading．Thevariousmaterialsfromwhichmostmetalcuttin