机械设计之简答题汇总.doc

机械设计之简答题汇总.doc机械设计之简答题汇总Connectingrodmechanism,theoffsetslidercrankmechanismandtheswingguiderodmechanismhavethecharacteristicsofquickreturnAnswer:thereisaquickreturncharacteristic,"deadcenterposition"ofthemechanism?Inwhatcircumstancesdoesthe"deadcenter,eandunderwhatcircumstancesshoulditbeused?A:inacrankrockermechanism,thispositionofthemechanismiscalledthedeadcenterpositionwhentheconnectingrodiscollinearwiththecrank〃・e,fixedclampinguse?,impactcharacteristicsandapplicationofthecammechanismfollower(themotionlawofthefollowerdependsontheshapeofthecam)Answer:the1awofconstantvelocitymotion,eleration,slowmotion,simpleharmonicmotion(cosine,acceleration,motion1aw);Thelawofconstantspeedmotionhasrigidimpact,whichisusedinlowspeedlightload:elerationanddecelerationmotionincludesflexibleimpact,middleandlowspeed;Thelawofsimpleharmonicmotion(elerationmotionlaw),andhasnoflexibleimpactwhenitisnotstopped・Itisusedinhigh-asions・4,underwhatcircumstances,thecammechanismofthedrivenrodtogetthemovementoftherest?Answer:earmaterials?monlyusedgearmaterials?thetoothsurfaceusesenoughhardness,inordertoresisttoothsurfacewear,pitting,bondingandplasticdeformation,,sothatitiseasytoprocess,,easytomanufactureetc・,forgedsteelformostofthegear,ing,steelcastinggearavailable,lowlightloadgearmaybemadeofcastirongearblank,nonmetalmaterialissuitableforhighspeedandlightload・asions・parethemainfailuremodesofgeardriveandwormdrive・Answer:boththemainfailureformsarepittingcorrosion,fracture,,scuffingfailureandwearmustbeconsideredfirst・Geartransmissionmainlydependsonpittingcorrosionandfracturefailure・7,pleaselistthegeneralpowertransm