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LOGOMachineElementsUnit2机械零件第2/57页上一页下一页机电专业英语徐存善主编TestingBeforeClass：Whatdoes“clutch”mean(radio)？“Clutch”是什么意思(单选)：提交第3/57页上一页下一页机电专业英语徐存善主编MachineElementsCouplingsCrankshaftsandConnectingrodsMachineToolClutchBearings第4/57页上一页下一页机电专业英语徐存善主编MachineElements第5/42页Text上一页下一页机电专业英语徐存善主编Howeversimple,anymachineisacombinationofindividualcomponentsgenerallyreferredtoasmachineelementsorparts.Thus,ifamachineiscompletelydismantled,acollectionofsimplepartsremainssuchasnuts,bolts,springsgears,camsandshafts—thebuildingblockofallmachinery1.Amachineelementis,therefore,asingleunitdesignedtoperformaspecificfunctionandcapableofcombiningwithotherelements.Sometimescertainelementsareassociatedinpairs2,suchasnutsandboltsorkeysandshafts.Inotherinstance,agroupofelementsiscombinedtoformasubassembly,suchasbearings,couplings,andclutches.第6/42页Text上一页下一页机电专业英语徐存善主编Themostcommonexampleofamachineelementisagear,which,fundamentally,isacombinationofthewheelandthelevertoformatoothedwheel.Therotationofthisgearonahuborshaftdrivesothergearsthatmayrotatefasterorslower,dependinguponthenumberofteethonthebasicwheels.第7/42页Text上一页下一页机电专业英语徐存善主编Otherfundamentalmachineelementshaveevolvedfromwheelandlever.Awheelmusthaveashaftonwhichitmayrotate.Thewheelisfastenedtotheshaftswithcouplings.Theshaftmustrestinbearings,maybeturnedbyapulleywithabeltorachainconnectingittoapulleyonasecondshaft.Thesupportingstructuremaybeassembledwithboltsorrivetsorbywelding4.Properapplicationofthesemachineelementsdependsuponknowledgeoftheforceonthestructureandthestrengthofthematerialsemployed.第8/42页Text上一页下一页机电专业英语徐存善主编Theindividualreliabilityofmachineelementsbecomesthebasisforestimatingtheoveralllifeexpectancyofacompletemachine.Manymachineelementsarethoroughlystandardized.Testingandpracticalexperiencehaveestablishedthemostsuitabledimensionsforcommonstructuralandmechanicalparts.Throughstandardization,uniformityofpracticeandresultingeconomicsareobtained.Notallmachinepartsinusearestandardized,however.Intheautomotiveindustryonlyfasteners,bearings,bushings,chains,andbeltsarestandardized.Crankshaftsandconnectingrodsarenotstandardized.第9/42页NewwordsandphrasesText上一页下一页机电专业英语徐存善主编combination[kCmbi5neiFEn]n.组合，结合individual[indi5vidjuEl]adj.单独的，各个的，个别的，特殊的component[kEm5pEunEnt]n.元件，构件，部件dismantle[dis5mAntl]vt.分解（机器），拆开，拆卸assemble[E5sembl]v.安装，装配，组合；集合，集中n组件nut[nQt]n.螺母；难对付的人；难解的问题；坚果vi.采坚果bolt[bEult]n.螺栓；（门、窗等的）插销gear[giE]n.仪器，装置；传动装置，齿轮cam[kAm]n.凸轮，偏心轮；样板，靠模，仿形板lever[5li:vE]n.杠杆，控制杆，操作杆shaft[FB:ft]n.柱身；连杆；传动轴，旋转轴；轴第10/42页NewwordsandphrasesText上一页下一页机电专业英语徐存善主编machinery[mE5Fi:nEri]n.机器(总称)associate[E5sEuFieit]v.联合，结合，参加，连带key[ki:]n.键，电键，开关；楔，销；钥匙subassembly[7sQbE5sembli]n.组合件，部件，机组coupling[5kQpliN]n.联轴节，联轴器；联结器，联合器clutch[klQtF]n.离合器，联轴器；夹紧装置fundamentally[fQndE5mentli]adv.（从）根本上hub[hQb]n.(轮)毂；中心；木片rotate[rEu5teit]n.(使某物)旋转或转动evolve[i5vClv]v.进化，演变；开展，发展，展开pulley[5puli]n.滑轮（组）；滑车；皮带轮第11/42页NewwordsandphrasesText上一页下一页机电专业英语徐存善主编rivet[5rivit]n.铆钉v铆接，铆weld[weld]v.&n.焊接，熔焊reliability[rilBiE5biliti]n.可靠性，安全性，准确性thoroughly[5WQrEli]adv.完全地，充分地，彻底地standardize[5stAndEdBiz]vt.标准化，统一标准；标定，校准establish[is5tAbliF]vt.确定，制定；建立，创办，产生；使固定dimension[di5menFEn]n.尺寸，尺度；范围，方面bushing[5buFiN]n.衬套；轴衬；轴瓦；[电]（绝缘）套管uniformity[7mju:ni5fC:miti]n.均匀性，一致性automotive[C:tE5mEutiv]adj.自动的，自动车的crank[krANk]n.曲轴refertoas称为，叫做；当做；参考作为；所说的；提到的第12/42页LanguagepointsText上一页下一页机电专业英语徐存善主编1.Thus,ifamachineiscompletelydismantled,acollectionofsimplepartsremainssuchasnuts,bolts,springsgears,camsandshafts—thebuildingblockofallmachinery.译文：因此，如果把机床完全拆开，就可以得到像螺母、螺栓、弹簧、齿轮、凸轮及轴等简单零件——所有机器的标准元件。第13/42页LanguagepointsText上一页下一页机电专业英语徐存善主编2.Sometimescertainelementsareassociatedinpairs.译文：某些特定的元件必须成对地工作。说明：beassociatedwith：与……有关；涉及又如：Iassociatedwithhiminbusiness.我与他和伙经商。Theseconcernsmaybeassociatedwithstrongfeelingssuchasangerorshame.这些忧虑很可能与恼火、羞愧之类的强烈情绪有关联。第14/42页LanguagepointsText上一页下一页机电专业英语徐存善主编3.Themostcommonexampleofamachineisagear,which,fundamentally,isacombinationofthewheelandthelevertoformatoothedwheel.译文：机器零件中最常用的是齿轮，它实际上是由轮子和杆组成的带有齿的轮子。说明：Which引导非限定性定语从句，修饰gear，不定式toformatoothedwheel作结果状语。第15/42页LanguagepointsText上一页下一页机电专业英语徐存善主编4．Thesupportingstructuremaybeassembledwithboltsorrivetsorbywelding.译文：支撑结构可由螺栓或铆钉或通过焊接固定在一起。说明：句中withboltsorrivetsorbywelding作方式状语，beassembledwith用……安装，又如：Thebookcasecaneasilybeassembledwithascrewdriver.这书柜用一把螺丝刀就可以很容易地安装起来。第16/42页ExercisesText上一页下一页机电专业英语徐存善主编I.Answerthefollowingquestions.1.Whatisreferredtoasamachineelement?Whichisthemostcommonmachineelement?2.Whatareotherfundamentalmachineelements?3.Whichmachineelementsarestandardizedintheautomotiveindustry?Amachineelementisasingleunitdesignedtoperformaspecificfunctionandcapableofcombiningwithotherelements.Themostcommonmachineelementisagear.Otherfundamentalmachineelementshaveevolvedfromwheelandlever.Intheautomotiveindustryonlyfasteners,bearings,bushings,chains,andbeltsarestandardized.keykeykey第17/42页ExercisesText上一页下一页机电专业英语徐存善主编II.Placea“T”(true)oran“F”(false)besidethesentencesaccordingtothetext.T1.Gearsareusedasbuildingblocksfortheconstructionofmostdevices,