機(jī)械制造專業(yè)英語

1.Thatbranchofscientificanalysiswhichmotions,timesandforcesiscalledmechanicsandismadeupoftwoparts,staticsanddynamics.研究位移、時(shí)間和力運(yùn)動(dòng)乘力是科學(xué)分析法的一個(gè)分歧，被稱作力學(xué)，力學(xué)由兩大部分組成，靜力學(xué)和動(dòng)力學(xué)。2.Forexample,iftheforceoperatingonasleevebearingbecomestoohigh,itwillsqueezeouttheoilfilmandcausemetal-to-metalcontact,overheatingandrapidfailureofthe軸承將過熱而迅速失效。3.Ourintuitiveconceptofforceincludessuchideasasplaceofapplication,direction,andmagnitude,andthesearecalledthecharacteristicsofaforce.力的直觀概念包括力的作用點(diǎn)、大小、方向，這些被稱為力的三要素。4.Allbodiesareeitherelasticorplasticandwillbedeformedifacteduponbyforces.Whenthedeformationofsuchbodiesissmall,theyarefrequentlyassumedtoberigid,i.e.,incapableofdeformation,inordertosimplifytheanalysis.所有的物體既可以是彈性的也可以是塑性的，如果受到力的作用就產(chǎn)生變形。當(dāng)變形很小的時(shí)候它們被假設(shè)成剛體，也就是不產(chǎn)生變形。5.Therigid-bodyassumptioncannotbeusedininternalstressesandstrainsduetotheappliedforcestobeanalyzed.Thusweconsiderthebodytobecapableofdeforming.剛體假設(shè)不能應(yīng)用于內(nèi)應(yīng)力和內(nèi)應(yīng)變的分析，所以在實(shí)際力的分析時(shí)，要考慮物體的形變。6.Ifalltheforcesactingonaparticlearebalanced,theparticlewilleitherremainatrestorwillcontinuetomoveinastraightlineatauniform如果作用在質(zhì)點(diǎn)上所有的力是平衡的，質(zhì)點(diǎn)將會保持靜止或做做勻速直線運(yùn)動(dòng)。7.Atensiletestconsistsofslowlypullingasampleofmaterialwithatensileloaduntilitbreaks.Theendsoftensilespecimensareusuallyenlargedtoprovideextraareaforgrip-pingandtoavoidhavingthesamplebreakwhereitisbeinggripped.拉伸試驗(yàn)包括慢慢加載拉伸載荷直到斷裂。拉伸試件兩端加粗為了提供裝夾區(qū)域和避免試件斷裂。8.Theusualmannerofconductingthetestistodeformthespecimenataconstantspeed.Forexample,intheuniversaltestingmachines,themotionbetweenthefixedandmovingcrossheadscanbecontrolledataconstantspeed.通常進(jìn)行試驗(yàn)的方法就是使試件以恒定速度發(fā)生變形。例如，在萬能拉伸試驗(yàn)機(jī)上，固定端和移動(dòng)的十字滑塊之間的變形是以恒定速度進(jìn)行的。9.Theloadthatmustbeappliedtoenforcethisdisplacementratevariesasthetestproceeds.ThisloadFmaybedividedbythecross-sectionalareaAtoobtainthestressinthespecimenatanytimeduringthetest.隨著實(shí)驗(yàn)的進(jìn)行，用來產(chǎn)生位移的載荷是隨位移的變化而變化。在實(shí)驗(yàn)中，載荷F除以橫截面積A可以得到任意時(shí)刻點(diǎn)的應(yīng)力。10.HoweveractualmeasurementofΔLispreferablewherethisisfeasible.Stressandstrainbasedontheinitial(undeformed)dimensions,AiandLi,arecalledengineeringstressandstrain.然而，在可行的位置上LAi和Li的應(yīng)力和應(yīng)變稱為工程應(yīng)力和工程應(yīng)變。11.Ductileandbrittlematerialsbehavedifferentlyincompressiontestaswell.Thecompressiontestisconductedonshortcylindricalspecimensplacedbetweenparallelplates.塑性和脆性材料在壓縮試驗(yàn)中表現(xiàn)的特性是不相同的。壓縮試驗(yàn)是把短圓柱形試件放在兩平行平板之間進(jìn)行的。12.Thecompressiontestdiagramforthesematerialsretainsthequalitativefeaturesofthetensiontestdiagram.Theultimatecompressivestrengthofabrittleofabrittlematerialisdeterminedinthesamewayasintension.材料壓縮試驗(yàn)圖保持了拉伸試驗(yàn)圖性能上的特征。脆性材料的最大壓縮強(qiáng)度與最大拉伸強(qiáng)度得到的方法相同。13.Virtuallyallmachinescontainshafts.Themostcommonshapeforshaftsiscircularandthecrosssectioncanbeeithersolidorhollow(hollowshaftscanresultinweight幾乎所有的機(jī)器都有軸，最常用的外形是圓形的，橫截面是空心的或?qū)嵭牡膱A形截面（空14.Ashaftmusthaveadequatetorsionalstrengthtotransmittorqueandnotbeoverstressed.Itmustalsobetorsionallystillenoughsothatonemountedcomponentdoesnotdeviateexcessivelyfromitsoriginalangularpositionrelativetoasecondcomponentmountedonthesameshaft.一個(gè)軸必須有足夠的扭轉(zhuǎn)強(qiáng)度來傳遞扭矩而不會破壞，同樣也必須有足夠的扭轉(zhuǎn)剛度，這樣安裝軸就不能過度偏離相對于安裝在同一軸上第二個(gè)零件的原始位置。15.Shaftsaremountedonbearingsandtransmitpowerthroughsuchdevicesasgears,pulleys,camsandclutches.Thesedevicesintroduceforceswhichattempttobendtheshaft;hence,theshaftmustberigidenoughtopreventoverloadingofthesupportingbearings.軸安裝在軸承上通過齒輪，滑輪，凸輪和離合器這些裝置傳遞力。這些裝置可以產(chǎn)生使軸彎曲的力，所以軸必修有足夠的剛性防止支撐軸承的過載。16.Inaddition,theshaftmustbeabletosustainacombinationofbendingandtorsionandbending.另外，軸必須能承載彎扭組合的載荷，因此，這樣就必須考慮彎扭組合的等效載荷。17.Componentssuchasgearsandpulleysaremountedonshaftsbymeansofkey.Thedesignofthekeyandthecorrespondingkeywayintheshaftmustbeproperlyevaluated.齒輪和滑輪構(gòu)件是用鍵的方式連接在軸上的，鍵和對應(yīng)的鍵槽的設(shè)計(jì)必須進(jìn)行估算。18.Anotherimportantaspectofshaftdesignisthemethodofdirectlyconnectingoneshafttoanother.Thisisaccomplishedbydevicessuchasrigidandflexiblecouplings.軸設(shè)計(jì)的另一個(gè)重要方面是直接連接兩軸，通過剛性和柔性的聯(lián)軸器裝置來實(shí)現(xiàn)。19.Pressureanglesforspurgearsareusually14.5or20degrees,althoughothervaluescanbeused.Meshinggearsmusthavethesamepressureangles.直齒輪的壓力角通常為14.5°或20其它的角度，嚙合齒輪必須具有相同的壓力角。20.Theshapeofthespacebetweengearteethonthegearaswellastoothmodule,somostgearmanufacturingmethodsgeneratethetoothflankinsteadofforming.的數(shù)目和模數(shù)變化而變化，因此大多數(shù)齒輪的加工方法是展成齒腹齒廓而不是齒形成形加工。21.Wormgearsareusedwherehighratiosaredesiredandwheretheshaftsarenonintersectingandatrightangles.蝸桿蝸輪應(yīng)用于傳動(dòng)比大而且兩軸不相交但相互垂直的情況下。22.Ithasthegreatadvantagethatthecuttingtoolisasimplerackwith(nearly)straightsidedteethwhichcaneasilybegroundaccurately.這種方法有很大的優(yōu)勢，切削工具是一個(gè)簡單的帶有直齒邊的齒條23.Modernshaperscuttingcargearscanrunat2000cuttingperminute.Theshapeofthecutterisroughlythesameasaninvolutegearbutthetipsoftheteetharerounded.現(xiàn)代切削汽車的成型器齒輪轉(zhuǎn)速可達(dá)每分鐘2000轉(zhuǎn)，齒刀形狀與漸開線大致相同，但齒頂是圓形的。24.Bevelgearsareoftenusedwhentwoshaftsareatrightanglestoeachotherandtheircenterlineextensionsintersect;however,somebevelgearsareatanglesotherthan90degrees.圓錐齒輪一般應(yīng)用于相互垂直的兩軸或兩個(gè)中心線延長線的相交軸中，也可用于不垂直的兩軸中。25.Thepurposeofanycamistoproduceadisplacementofitsfollower;asecondaryfollowerisoftenusedtoproduceadditionaldisplacementinanotherlocation.使用凸輪的目的是使從動(dòng)件產(chǎn)生位移，次級從動(dòng)件在另一位置產(chǎn)生附加運(yùn)動(dòng)。26.TherelativeverticalpositionofpointAwithrespecttoBneedstoberaisedifthereactionvalueatBis如果B點(diǎn)的作用力過大，A點(diǎn)相對B點(diǎn)的相對垂直位置必須被提高。27.Ingeneral,thefollowerisconsideredtobethepartthatcomesincontactwiththecamprofile.However,whenasecondaryfollowerisused,themotionofthesecondaryfollowerisdictatedbythatoftheprimary總的來說，從動(dòng)件是與凸輪輪廓相接觸的零件，然而，當(dāng)用次級從動(dòng)件時(shí)，次級從動(dòng)件的運(yùn)動(dòng)就需通過主要從動(dòng)件來實(shí)現(xiàn)。28.Thesimplesttypeoffolloweristhereciprocatingtypethatmerelymovesupanddown(orinandout)withtherotationofthecam;thecenterlinecanbeeithercollinearwiththecamcenterlineoroffsetform運(yùn)動(dòng)的從動(dòng)件，其中心線可與凸輪中心共線，也可與之偏離。29.Fastenersaredeviceswhichpermitoneparttobejoinedtoasecondpartand,hence,theyareinvolvedinalmostalldesigns.緊固件是一種連接一個(gè)部分和另一個(gè)部分的裝置，因此，它涉及到幾乎所有的設(shè)計(jì)。30.Springsaremechanicalmemberswhicharedesignedtogivearelativelylargeamountofelasticdeflectionundertheactionofanexternallyappliedload.彈簧是一種被設(shè)計(jì)于在外力作用下產(chǎn)生相對彈性變形較大的機(jī)械構(gòu)件。31.Thelubricationsystemprovidesaconstantflowoffilteredoiltoallmovingpartsoftheengine.Thesystemconsistsofanoilpantostoretheoil,apumptocirculateit,afiltertoremovesolidabrasiveparticles,andanoilgaugeorlightindriver’scompartmentforcheckingpurposes.32.Thedrivelineconsistsofmechanismsandunitswhichtransmittorquefromtheenginetothedrivewheelsandchangetorqueandrpminmagnitudeanddirection.33.Ithasbeenseenthatiftheconditionsarenotveryabnormal,sufficientamountoftyresliptakingplaceunderrunningconditionswouldreleasethesestressescompletely.34.Mucheffortisrequiredtocranktheengineduringstarting,sinceitisnecessarytoovercomefrictioninthemovingenginecomponentsandtheresistanceofferedbythechargebeingcompressed.35.Theclutchisafrictiondeviceusedtoconnectanddisconnectadrivingforcefromadrivenmember.Itisusedinconjunctionwithanengineflywheeltoprovidesmoothengagementanddisengagementoftheengineandmanualtransmission.36.Thedifferentialisagearsystemthattransferspowerfromthedriveshafttothedrivingaxles.Italsopermitsonedrivingwheeltoturnfasterthantheothertopreventskiddingandscuffingoftiresonturns.37.Thefirststageintheproductionofsandcastingmustbethedesignandmanufactureofasuitablepattern.Castingpatternhastobemadelargerthanthefinishedcastingsizetoallowfortheshrinkagethattakesplaceduringsolidificationandcooling.在型砂鑄造生產(chǎn)中，第一階段是必須設(shè)計(jì)和制造合適的模型，考慮到鑄件在凝固和冷卻期間產(chǎn)生的收縮鑄件模型的尺寸要比鑄件的尺寸大。38.Ifahollowcastingistobemadethepatternwillincludeextensionpiecessothatspacestoacceptthesandcorearemoldedintothesand.Theseadditionalspacesinthemoldaretermedcoreprints.如果鑄造空心鑄件時(shí)模型上包含伸長桿便于在砂中放置砂芯的空間稱為型芯座。39.Sandmoldsfortheproductionofsmallandmedium-sizedcastingsaremadeinamoldingbox.Themoldismadeintwoormorepartsinorderthatthepatternmayberemoved.中小型尺寸的鑄件砂型是在一個(gè)砂箱中制造，砂型由兩部分或更多部分組成，以利于模型的順利取出。40.Thisprocessoffillingandrammingmaybedonebyhandbutmoldproductionisautomatedinalargefoundrywiththemoldboxesmovingalongaconveyor,firstlytobefilledwithsandfromhoppersandthentopassundermechanicalhammersforramming.填充和夯實(shí)的過程可以手工完成，但在大型鑄造中砂型的制造是自動(dòng)完成的，砂箱隨著傳送帶移動(dòng)，首先被料斗中的砂子填滿，然后通過機(jī)械錘時(shí)被打?qū)崱?1.Therisersshouldcoincidewiththehighestpointsofthemoldcavitysothatthedisplacedaircanreadilyescapefromthemold.Thesizesofrisersshouldbesuchthatthemetalinthemdoesnotfreezetoorapidly.冒口應(yīng)該與型腔的最高點(diǎn)相連接，使得進(jìn)入的空氣可以容易的從模型中溢出，冒口的尺寸應(yīng)該足夠大使模型中金屬不會太快凝固。42.Whenthemetalthathasbeenpouredintoasandmoldhasfullysolidified,themoldisbrokenandthecastingisremoved.Thecastingstillhastherunnerandrisersattachedtoitandtherewillbesandadheringtoportionsofthesurface.當(dāng)熔的金屬被傾倒到砂型內(nèi)并充分凝固以后，砂型將被打破取出鑄件，鑄件上依然帶有橫澆口和冒口并且依然有砂子粘在表面。43.Forgingmeanstheshapingofmetalbyaseriesofhammerblows,orbyslowapplicationofpressure.Thesimplestexampleisablacksmithsforgingofahotpieceofmetalbyhammeringthework-pieceonananvil.鑄造是通過一系列的錘打或是在緩慢的加載壓力的場合使金屬成型的一種方法，最簡單的實(shí)例就是熱的金屬的自由鍛，即通過鐵砧上錘打鍛件。44.Heavysmithsforgingisfundamentallysimilar,differingonlyinthescaleoftheoperation.Thework-piecemaybeaningotof100tonsandthedeformingforceprovidedbyamassiveforginghammer,butthewholeprocessiscontrolledbythemastersmith,whodecideseachtimewhere,andwithwhatforce,theblowshouldtakeplace.重型自由鍛和自由鍛基本相似，僅在操作的規(guī)模上有所不同，鍛件可以是一個(gè)100噸的鐵塊，鍛壓力由一個(gè)巨大的鍛錘提供，但是整個(gè)鍛造過程由操作者控制。他來決定什么時(shí)候用多大力打到什么地方。45.Forgingoperationsmaybecarriedoutusingeitherforginghammersorforgingpresses.Withapress,asopposedtoahammer,pressureisslowlyappliedandplasticdeformationtendstooccurfairlyuniformlythroughoutthematerial.鍛造操作者既可以用鍛錘也可以用鍛壓力來實(shí)現(xiàn)操作，用鍛壓力和鍛錘相反，在壓力緩慢作用使整個(gè)均勻桿產(chǎn)生塑性變形的趨勢。46.Forginghammersareoftwobasictypeswiththelargehammereitherdroppingontothework-pieceacceleratedbygravityaloneor,asinthesteamhammer,acceleratedbybothgravityandsteampressure.鍛錘有兩種基本類型，既可以用很大的錘子通過作用在工件上也可以用蒸汽壓力作用在工件上或者是兩者結(jié)合。47.Smithsoropen-dieforgingisusedformakingverylargeforgingsorwhenthenumberofforgingsofaparticulardesignissmall.Open-dieforgingisalsousedtopreformmetalpriortofinalshapingbymeansofclosed-die自由鍛或開模鍛用于制造大型的鍛件或者特殊設(shè)計(jì)的小鍛件，開模鍛用于預(yù)成型金屬，在最終金屬成型之前通常使用閉模鍛。48.Closed-dieforginginvolvestheuseofaccuratelymachineddieblocks.Thecapitalcostofapairofdieblocksishigh,butthisisallowablewhenitisrequiredtomakeforgingstoclosedimensionaltolerancesandinlargequantity,aswouldbethecasefor,say,connectingrodsfortheengineofapopularcar.閉模鍛包