机械基础习题(2)(国外英语资料)

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1、机械基础习题(2)InJuly2009,thenationalcollegeofadvancededucationself-studyexamBasicdesignofmechanicaldesignCoursecode:02185One,asinglechoiceofchoice(20shortquestions,2points,40points)Onlyoneofthefourcandidateslistedineachoftheitemsiseligibleforthetitle.Pleasefil

2、linthefollowingbrackets.Neitherchoice,choice,norchoiceisall.Theunitofmotioninthemachineiscalled()A.partsB.memberC.componentsPartD.Inaflatorganization,eachadditionallowvicewillbeintroduced()A.0constraintB.aconstraintC.twoconstraintsD.threeconstraintsTheAng

3、leiszerowhenthecrankmechanismisdead.4.ThepressureAngleB.transmissionAngleC.polepositionAngleD.angularIfthelengthoftheshortestrodandthelengthofthelongestbarisgreaterthanthesumoftheremainingtworods,themechanismis().A.CranklevermechanismB.crankblockmechanism

4、C.doublecrankmechanismD.twinrockerWhentheCAMmechanismisusedfortheuniformmotion,itsfollowermotion().A.itwillcreateArigidimpactB.willhaveaflexibleimpactC.thereisnoimpactD.BothrigidandflexibleThemovementtransformoftheslottingmechanismis()A.Theconstantspeedof

5、constantrotationisintermittentrotationB.TurnstomoveCDIfoneofthejointsislarge,thematerialissoft,thestrengthislow,andtheneedtobeconstantlyinstalled,itisappropriatetoadopt().A.boltcouplingB.screwconnectionC.doubleheadstudconnectionD.tightenthescrewThefaceoft

6、hecommonwedgeisthekey().AtopandbottomsurfaceB.undersideC.thetwosidesD.twofaceTheflatbelt,Vbelttransmissionmotionandpoweraremainlydependenton()ThetensionpullofAB.TheloosepullofthebeltThepre-tensionforceofthebeltThefrictionbetweenthebeltandthesurfaceofthewh

7、eelTheshapeoftheprofileoftheinvolutegearisdependenton()Graduationcircleofa.B.basecircleC.dedendumcircleD.addendumcircleIngeartransmission,thefatigueofgeartoothsurfaceoftenoccursin()Toothrootparta.B.neartherootofthelineC.addendumpartD.nearthetopofthesectio

8、nofthesectionThecharacteristicsofthesurfacecontactstressinthegearsarereducedto().A.pulsatingcyclicstressB.symmetricalcyclicstressC.unchangedstaticstressD.IrregularstressChoosingthewormgearisusuallybasedonthewormdriv