機(jī)電英語課件Unit 1

MachineElementshttp://大連理工大學(xué)出版社Unit1機(jī)電英語ContentsSimulatedWriting2Reading31Speaking33PartⅠPassageA

Howeversimple,anymachineisacombinationofindividualcomponentsgenerallyreferredtoasmachineelementsorparts.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?凸輪及軸等簡單零件——所有機(jī)器的組合元件?if引導(dǎo)條件狀語從句,表示“如果……”?T無論任何簡單的機(jī)床，都是由單一元件即通稱為機(jī)械零件或部件組成的。因此，如果把機(jī)床完全拆卸，就可得到像螺母、螺栓、彈簧、齒輪、凸輪和軸等簡單零件——所有機(jī)器的組合元件。

Thus,ifamachineiscompletelydismantled,acollectionofsimplepartsremainssuchasnuts,bolts,springs,gears,camsandshafts—thebuildingblockofallmachinery.1

MachineElementsPartⅠPassageAAmachineelementis,therefore,asingleunitdesignedtoperformaspecificfunctionandcapableofcombiningwithotherelements.suchasnutsandboltsorkeysandshafts.Inotherinstance,agroupofelementsarecombinedtoformasubassembly,suchasbearings,couplingsandclutches.T因此，機(jī)械零件就是可以執(zhí)行某種具體功能，而且能與其它零件配合的簡單零件。有時(shí)候某些特定的元件必須成對的工作，例如螺栓與螺母，鍵與軸。在有些情況下，一組零件組成一裝配件，比如：軸承、聯(lián)軸器與離合器。有時(shí)某些特定的元件必須成對地工作……beassociatedinpairs:成對地結(jié)合例如:Iamassociatedwithhiminbusiness.我與他兩人合伙經(jīng)商?

Sometimescertainelementsareassociatedinpairs,2

MachineElementsPartⅠPassageAT機(jī)械零件中最常見的是齒輪，它實(shí)際上是由輪子和桿組合并帶有齒的輪子。在軸轂或軸上旋轉(zhuǎn)的齒輪驅(qū)動(dòng)其他齒輪做加速或減速運(yùn)動(dòng)，這取決于主動(dòng)齒輪的齒數(shù)。機(jī)器零件中最常見的是齒輪,它實(shí)際上是由輪子和桿組成的帶有齒的輪子?在輪轂或軸上旋轉(zhuǎn)的齒輪驅(qū)動(dòng)其他齒輪做加速或減速運(yùn)動(dòng),這取決于主動(dòng)齒輪的齒數(shù)?which引導(dǎo)非限制性定語從句,修飾gear;不定式短語toformatoothedwheel作結(jié)果狀語;分詞短語dependingupon作原因狀語?Themostcommonexampleofamachineelementisagear,which,fundamentally,isacombinationofthewheelandthelevertoformatoothedwheel.Therotationofthisgearonahuborshaftdrivesothergearsthatmayrotatefasterorslower,dependinguponthenumberofteethonthebasicwheels.3

MachineElementsPartⅠPassageAOtherfundamentalmachineelementshaveevolvedfromwheelandlever.Awheelmusthaveashaftonwhichitmayrotate.Thewheelisfastenedtotheshaftswithcouplings.Theshaftmustrestinbearings,maybeturnedbyapulleywithabeltorachainconnectingittoapulleyonasecondshaft.T其他基本機(jī)械零件包含輪子和桿。輪子必須裝在軸上才可以轉(zhuǎn)動(dòng)。輪子用聯(lián)軸器夾緊固定在軸上，軸必須安裝在軸承里，由帶或鏈條與第二根軸相連，并帶動(dòng)第二根軸轉(zhuǎn)動(dòng)。

MachineElementsPartⅠPassageAProperapplicationofthesemachineelementsdependsuponknowledgeoftheforceonthestructureandthestrengthofthematerialsemployed.T支承結(jié)構(gòu)可用螺栓、鉚釘或通過焊接固定裝配在一起。這些機(jī)械零件的正確使用，取決于是否懂得作用于結(jié)構(gòu)上的力和所用材料的強(qiáng)度等相關(guān)方面的知識(shí)。支撐結(jié)構(gòu)可由螺栓或鉚釘或通過焊接固定在一起?beassembledwith:由……安裝;bywelding作方式狀語?Thesupportingstructuremaybeassembledwithboltsorrivetsorbywelding.4

MachineElementsPartⅠPassageATheindividualreliabilityofmachineelementsbecomesthebasisforestimatingtheoveralllifeexpectancyofacompletemachine.Manymachineelementsarethoroughlystandardized.Testingandpracticalexperiencehaveestablishedthemostsuitabledimensionsforcommonstructuralandmechanicalparts.T單個(gè)機(jī)械零件的可靠性成為評估整臺(tái)機(jī)器使用壽命的基本因素。很多機(jī)械零件是完全標(biāo)準(zhǔn)化的。普通結(jié)構(gòu)和機(jī)械部件的最適合的尺寸可以借助測試或?qū)嶋H經(jīng)驗(yàn)來確定。

MachineElementsPartⅠPassageAThroughstandardization,uniformityofpracticeandresultingeconomicsareobtained.Notallmachinepartsinusearestandardized,however.Intheautomotiveindustryonlyfasteners,bearings,bushings,chainsandbeltsarestandardized.Crankshaftsandconnectingrodsarenotstandardized.T采用標(biāo)準(zhǔn)化可以獲得實(shí)際應(yīng)用上的一致性和經(jīng)濟(jì)上的實(shí)惠。然而，并非所有的零件都是標(biāo)準(zhǔn)的。在自動(dòng)化工業(yè)中，只有緊固件、軸承、軸套、傳動(dòng)鏈和傳動(dòng)帶是標(biāo)準(zhǔn)元件。曲軸及連桿并不是標(biāo)準(zhǔn)元件。

MachineElementsPartⅠPassageA1.Whatisamachineelement?ExercisesⅠ.Answerthefollowingquestionsaccordingtothepassage.Amachineelementisasingleunitdesignedtoperformaspecificfunctionandcapableofcombiningwithotherelements.2.Whichisthemostcommonmachineelement?Themostcommonexampleofamachineelementisagear,which,fundamentally,isacombinationofthewheelandthelevertoformatoothedwheel.3.Whatareotherfundamentalmachineelements?Otherfundamentalmachineelementshaveevolvedfromwheelandlever.PartⅠPassageAExercisesⅠ.Answerthefollowingquestionsaccordingtothepassage.4.Whichelementisregardedasthebasisforestimatingtheoveralllifeexpectancyofacompletemachine?Thereliabilityofindividualmachineelements.5.Whichmachineelementsarestandardizedintheautomotiveindustry?Intheautomotiveindustryonlyfasteners,bearings,bushings,chainsandbeltsarestandardized.PartⅠPassageAExercisesⅡ.Translatethefollowingphrases.

1.機(jī)械零件machineelement2.簡單零件simplepart 3.自動(dòng)化工業(yè)theautomotiveindustry4.單一元件individualcomponent5.主動(dòng)齒輪thebasicwheel6.theindividualreliabilityofmachineelements機(jī)械零件的可靠性7.theoveralllifeexpectancyofacompletemachine整臺(tái)機(jī)器使用壽命

8.thebuildingblockofthemachinery機(jī)器的組合元件

9.thesupportingstructure支撐結(jié)構(gòu)

10.thestrengthofthematerials材料強(qiáng)度

PartⅠPassageAExercisesⅢ.Fillintheblankswiththeproperwordslistedinthebox.Changethewordformifnecessary.Standardize reliable machinery componentuniformexpectancy assemble individual gearestimate1.Complexmachinesaremadeupofmovingpartssuchaslevers,cams,cranks,springs,beltsandwheels.2.Itcanalsobeusedtothepropertiesofthematerials.3.Theisrequiredpropertiesofthemachineelements.4.AgriculturalPowerOperationisoperatingtractorsandagriculturalequipment.gears_______standardize____________reliability___________machinery___________PartⅠPassageAExercisesStandardize reliable machinery componentuniformexpectancy assemble individual gearestimate5.Ageneratorwillreadspecificationsofrequiredvariants,customizeaffectedcomponentsandthemintoacustomsystem.6.Youmayuseequipments,instrumentsortoolstoidentifybadengine.7.Aponents___________assemble___________uniformity___________PartⅠPassageAExercisesStandardize reliable machinery componentuniformexpectancy assemble individual gearestimate8.Youshouldcostsandenergyproductionusingsomebaseassumptions.9.Ithasalongerlifethanconcreteandsteelequipment.10.Youcanemploythismethodtoanalyzeelectrical

componentsofacompletemachineforproperoperation.expectancy___________individual___________estimate__________PartⅠPassageAExercisesⅣ.TranslatethefollowingsentencesintoEnglish.1.最常見的機(jī)械零件是齒輪,齒輪實(shí)際上是由輪子和桿組成的帶齒的輪子?Themostcommonmachineelementisthegear,whichisacombinationofthewheeland

thelevertoformatoothedwheel.2.齒輪的硬度決定了它的耐磨能力?Thehardnessofageardeterminesitsabilitytoresistwear.3.制造業(yè)的工程師們集中精力研制標(biāo)準(zhǔn)化的零件?Manufacturingengineershavecenteredtheireffortsonthedevelopmentofstandardizedelements.PartⅠPassageAExercisesⅣ.TranslatethefollowingsentencesintoEnglish.4.這些零件是在大批量?高規(guī)格和低成本的條件下生產(chǎn)的?Thesepartsareproducedinlargequantitieswithahighdegreeofperfectionatreduced cost.5.可以說,零件表面是零件和設(shè)備的功能信息的載體?Itseemsthattheelementsurfaceisthecarrieroffunctionalinformationforbothmachineelementandprocessingapparatus.6.這些機(jī)械零件的正確使用,取決于是否懂得作用于結(jié)構(gòu)上的力和所用材料的強(qiáng)度等相關(guān)方面的知識(shí)?Properapplicationofthesemachineelementsdependsuponknowledgeoftheforceon thestructureandthestrengthofthematerialsemployed.PartⅠPassageBAgearhavingtoothelementsthatarestraightandparalleltoitsaxisisknownasaspurgear.Aspurgearcanbeusedtoconnectparallelshaftsonly.Parallelshafts,however,canalsobeconnectedwithgearsofanothertype,andaspurgearcanbematedwithagearofadifferenttype.

SpurandHelicalGears

TranslationPartⅠPassageB返回TranslationPassageA正齒輪和斜齒輪

輪齒是直的并平行于其軸線的齒輪稱為正齒輪。正齒輪只能與平行軸傳動(dòng)聯(lián)結(jié)。然而，平行軸還可與其他類型的齒輪傳動(dòng)聯(lián)結(jié)，一個(gè)正齒輪可與不同類型的齒輪相嚙合。

PartⅠPassageBTopreventjammingasaresultofthermalexpansion,toaidlubricationandtocompensateforunavoidableinaccuraciesinmanufacture,allpower-transmittinggearsmusthavebacklash.Thismeansthatonthepitchcirclesofamatinggear,thespacewidthonthepinionmustbeslightlygreaterthanthetooththicknessonthegearandviceversa.Oninstrumentgears,usingagearsplitdownitsmiddle,onehalfbeingratablerelativetotheotherscaneliminatebacklash.Aspringforcesthesplitgearteethtooccupythefullwidthofthepinionspace.

SpurandHelicalGears

TranslationPartⅠPassageB返回TranslationPassageA為了避免受熱膨脹而引起的卡死現(xiàn)象，方便潤滑和補(bǔ)償不可避免的制造誤差，所有的動(dòng)力傳動(dòng)齒輪必須有側(cè)隙。也就是說在一對嚙合齒輪的節(jié)圓上，小齒輪的齒槽寬必須稍大于大齒輪的齒厚，反過來也是如此。對于儀表齒輪，側(cè)隙可通過將一個(gè)齒輪從中間切開而獲得的兩個(gè)“拼合”齒輪來消除，拼合齒輪的一半與另一半是成比例的。彈簧力能使拼合齒輪占滿小齒輪的齒間全部寬度。PartⅠPassageBHelicalgearshavecertainadvantages,forexample,whenconnectingparallelshafts,theyhaveahigherloadcarryingcapacitythanspurgearswiththesametoothnumbersandcutwiththesamecutter.Becauseoftheoverlappingactionoftheteeth,theyaresmootherinactionandcanoperateathigherpitch-linevelocitiesthanspurgears.Thepitch-linevelocityisthevelocityinthepitchcircle.Sincetheteethareinclinedtotheaxisofrotation,helicalgearscreateanaxialthrust.Ifusedsingle,thisthrustmustbeabsorbedintheshaftbearings.Thethrustproblemcanbeovercomebycuttingtwosetsofopposedhelicalteethonthesameblank.

SpurandHelicalGears

TranslationPartⅠPassageB返回TranslationPassageA斜齒輪具有一些優(yōu)點(diǎn)，比如當(dāng)連接平行軸時(shí)，其承載能力高于有相同齒數(shù)并用相同刀具切削的正齒輪。因?yàn)檩嘄X的重合作用，其傳動(dòng)更加平穩(wěn)，允許的節(jié)線速度比正齒輪高。節(jié)線速度是節(jié)圓上的線速度。由于輪齒傾斜于旋轉(zhuǎn)軸線，所以斜齒輪會(huì)產(chǎn)生軸向推力。如果單獨(dú)使用這種齒輪，軸向推力由軸向軸承來承擔(dān)。軸向推力問題可通過在一個(gè)齒胚上加工兩對斜齒來解決。PartⅠPassageBDependingonthemethodofmanufacture,thegearmaybeofthecontinuous-toothherringbonevarietyoradouble—helicalgearwithaspacebetweenthetwohalvestopermitthecuttingtooltorunout.Double—helicalgearsarewellsuitedfortheefficienttransmissionofpowerathighspeeds.Helicalgearscanalsobeusedtoconnectnonparallel,non-intersectingshaftsatanyangletooneanother.Ninetydegreesisthecommonestangle,atwhichsuchgearsareused.

SpurandHelicalGears

TranslationPartⅠPassageB返回TranslationPassageA依照加工方法，這種齒輪可以是連續(xù)齒人字型輪齒或有退刀槽的雙斜齒輪。雙斜齒輪特別適合于在高速下高效傳遞動(dòng)力。斜齒輪還能用于相互成任何角度的不平行或不交叉的軸間連接，最常見的連接角度為90°。

PartⅡSimulatedWriting與商業(yè)函件相比,傳真和電子郵件不但快捷,而且也比快件便宜,因此其應(yīng)用范圍越來越廣?它們的格式與普通信函相似,但略有不同:傳真信頭中含有傳真號(hào)碼和電話號(hào)碼,信內(nèi)地址往往被收件人的傳真號(hào)碼和電話號(hào)碼所代替;電子郵件則大多無信頭內(nèi)容,只有收件人的電子郵件地址及事由等?

傳真和電子郵件

一?傳真(Fax)Sample1Sample2PartⅡSimulatedWriting返回Sample1VS(China)ElectronicsCo.,Ltd.GDProvince,P.R.China518527Tel:86-755-27711288Fax:86-755-27711289FaxCoverSheetTo:至:SalesManagerPhilipsSoundSystems(PSS)Corp.From:自:TerryMadisonMarketingManagerPhone:電話:Fax:傳真:17-4821-5231317-4821-52315Phone:電話:Fax:傳真:86-755-2771128886-755-27711289DateofIssue:發(fā)出日期:Sep.16,2007TotalPages:發(fā)出頁數(shù):1(Includingthispage)DearSirorMadam,RE:ComplaintaboutthePoorQualityofWoofers(低音喇叭,擴(kuò)音器)Pleasebeinformedthatthewoofers(PN(產(chǎn)品編號(hào)):439929155236)youdeliveredonSep.15werefoundwithunacceptablyhighrateofbrokenconepaper(紙盆,喇叭中的一種物料)aftersamplinginspectionbyourQCinspectors,whichcausedconsiderabledecreaseinourdailyproduction.WeenclosetheInspectionReportherewith,andhavesent5defectivesamplestoyou.Pleasefeedbackyouranalysisreportandimprovementplanwithinoneweek.Ifthiscaserecurs,wewillhavetorejectlaterlots.YoursFaithfully,TerryMadisonMarketingManagerPartⅡSimulatedWriting返回Sample2HerbertImport&Export.Telephone:(212)2215608Fax:(212)2215706Address:388StationStreet,NewYork,10018U.S.A.To:JohnsonCompanyDate:May23,2003Attn:EricLeeFrom:SimonDavisYourRef:2051/efOurRef::5237/nlCC:KateLongPage:1DearSir,WeareanAmericancompany;oursharesaretobeissuednextmonth.OurcompanyistobegrantedaWorldBankcreditsoon.Shouldyoubeinterestedincooperationorinbuyingourshares,pleasedonothesitatetocontactus.Welookforwardtohearingfromyou.YoursSincerely,SimonDavisManagingDirectorTranslationPartⅡSimulatedWriting返回Translation赫伯特進(jìn)出口公司電話：（212）2215608傳真：（212）2215706地址：美國紐約車站街388號(hào)10018發(fā)送：約翰遜公司日期：2003年5月23日收件人：埃里克?李發(fā)件人：西蒙?戴維斯貴方編號(hào)：2051/ef我方編號(hào)：5237/nl抄送：凱特?朗頁數(shù)：1先生：我方為一家美國公司，我方股票將于下月發(fā)行。本公司即將得到世界銀行的一筆貸款。貴方如有興趣與我方合作，或購買我方股票，敬請與我們聯(lián)系。恭盼回復(fù)。 你忠實(shí)的 西蒙?戴維斯總經(jīng)理PartⅡSimulatedWritingRef(reference)—信函參考編號(hào),一般編號(hào)往往包括有關(guān)人員的姓名的首字母?OurRef—我方編號(hào),即發(fā)信人編號(hào)YourRef—貴方編號(hào),即收信人編號(hào)Attn—收件人CC—抄送(其他收件人)以上例文中的所有內(nèi)容并非每一篇傳真都必須具備的,但是,每一篇傳真都不能缺少的內(nèi)容是:To—收件人的姓名(后面可以加地址)From(FM)—發(fā)件人的姓名(后面可以加地址) Date—發(fā)傳真的日期(月份一般用字母)Fax—收件人的傳真號(hào)碼 Sub—事由 Thesalutation—稱呼(和信函相同) Thebodyofthetelex—電郵正文(和信函相同)Regards—致意(和信函相同) Signature—署名(和信函相同)傳真格式要求

PartⅡSimulatedWriting1.電郵的格式To—收件人的e-mail地址 Subject—主題正文Thesalutation—稱呼(和信函相同)Thebodyofthetelex—電郵正文(和信函相同)Regards—致意(和信函相同) Signature—署名(和信函相同)2.英文電子郵件的基本寫作技巧

其實(shí),寫電郵和寫英文信相差不多,主要由稱呼?正文和落款三部分構(gòu)成?寫作正文時(shí)要注意以下兩點(diǎn):(1)首先要明確寫給誰?不同的收件人,語氣不同?寫給朋友的可用一些俚語或縮寫詞語,但是在比較正式的場合中,就不能用俚語或縮略語?(2)寫電子郵件要直接,并多用短句,使意思清楚?當(dāng)然,對重點(diǎn)部分要作詳細(xì)介紹?

二?電郵(E-mail)

SamplePartⅡSimulatedWriting返回SampleTo:Smith885@Subject:AboutmyselfDearMrandMrsSmith,I’maChinesegirl.MynameisYangLi.I’mveryhappytoknowthatI’llstayatyourhousefortheEnglishSummerCamp.I’dliketotellyousomethingaboutmyselfsothatyoucanknowabitaboutmebeforeIarrive.I’mfifteenyearsold.Ihaveahappyfamilywiththreepeople.I’mstudyinginNo.1MiddleSchool.Welearneightsubjects.I’minterestedinallofthem.Ilikereadingandplayingthepiano.IlikeEnglishverymuch,butmyEnglishisnotgoodenough.IthinkyoucanhelpmewithmyEnglish.Ihopetomeetyousoon. YoursTruly, YangLiPartⅡSimulatedWriting(1)在稱呼處對方的名字不要拼錯(cuò)?頭銜也不要錯(cuò),頭銜?學(xué)位任選其一?(2)人較多時(shí),可用Ladiesandgentlemen?

Notes假如你叫方芳,在因特網(wǎng)上找到了一個(gè)叫Joyce的網(wǎng)友,現(xiàn)在請你根據(jù)下列要點(diǎn)給Joyce發(fā)e-mail,介紹你自己的一些情況?a.方芳,中學(xué)生,家住在重慶;b.喜歡集郵和運(yùn)動(dòng);c.對英語很感興趣,會(huì)唱幾首英文歌曲;d.班里同學(xué)也想找網(wǎng)友,希望得到幫助;e.想去英國看看?PracticePartⅢSpeaking(I=interviewer主試人A=applicant應(yīng)試人)Dialogue1I:Wheredoyoulive?A:IliveatApt.401,126ZhongshanRoad,Nanjing.I:What’syourpermanentaddress?A:MypermanentaddressisApt.401,126ZhongshanRoad,Nanjing.I:Whereisyourbirthplace?HometownandEducationBackgroundA:MybirthplaceisSuzhou.I:AreyouaresidentofShanghai?A:No.I:Whereisyourdomicileplace?A:MydomicileplaceisNanjing.I:Givemeyourtelephonenumber,please.A:(Mytelephonenumberis)8563361PartⅢSpeakingHometownandEducationBackgroundDialogue2I:What’syouraddress?A:Myaddressis356HepingRoad,Xuzhou.I:Whereareyouworking?A:I’mworkingatPing’anHotelatHuaihaiRoad.I:Whereisyourhometown?A:MyhometownisSuzhou.I:Areyoualocalresident?A:Yes,Iam.IhavebeenlivinginSuzhousinceIgraduatedfromuniversity.PartⅢSpeakingHometownandEducationBackgroundDialogue3I:Wouldyoutellmesomethingaboutyoureducationalbackground?A:Yes,sir.Igraduatedfrommiddleschoolin1986,thenIenteredShanghaiPolytechnics.Igraduatedin1992,andIhaveaB.S.degree.I:Whatdepartmentdidyoustudyin?A:IwasintheDepartmentofPhysics.I:Howwereyourscoresatcollege?A:Theywereallexcellent.PartⅢSpeak