机械毕业设计英文外文翻译多速变速箱的优化设计传动部件的建模.docx
- 文档编号:8906418
- 上传时间:2023-02-02
- 格式:DOCX
- 页数:17
- 大小:482.11KB
机械毕业设计英文外文翻译多速变速箱的优化设计传动部件的建模.docx
《机械毕业设计英文外文翻译多速变速箱的优化设计传动部件的建模.docx》由会员分享,可在线阅读,更多相关《机械毕业设计英文外文翻译多速变速箱的优化设计传动部件的建模.docx(17页珍藏版)》请在冰豆网上搜索。
机械毕业设计英文外文翻译多速变速箱的优化设计传动部件的建模
OPTIMUMDESIGNOFMULTISPEEDGEARBOXESAND
MODELINGOFTRANSMISSIONCOMPONENTS
Prof.drBožidarRosić,drAleksandarMarinkovic,MrAleksandarVencl
Abstract:
Byapplyingtheoptimumdesigninthefieldofgeartransmissiondesignitispossibletodefinetheoptimalrelationsbetweentheparametersofthecompletegeartransmission,andofeachtransmissionstageseparately.Thispaperpresentsaonecriterionprocedureforgeartransmissionoptimizationandmulticriterionoptimizationprocedureforeachtransmissionstage.Secondpartofthepaperisfocusedonmodelingofcylindricalgearsthatarecommonusedmachineelementsandmainpartsofgeartransmissions.ThesemodelsaremadeusingpartandassemblydesignmoduleinCATIAV5R11software.Ontheendofpapersomeapplicationsofmodelsinfiniteelementsanalysisandoptimizationarealsodescribed。
Keywords:
optimumdesign,multistagegearbox,computeraddeddesign,gearsmodeling,CATIA
1.Introduction:
Conceptfromoptimizationanddecisiontheorycanplayanimportantroleinallstagesthedesignprocess.Theoptimizingdesigntheoryapplyingandmethodologywillbeillustratedonamultispeedgearboxexample.Gearboxespresentaveryimportantgroupofmachinemembers,whichareutilizedinagreatnumberofengineeringfieldsandwhichmustsatisfyveryrigoroustechnicalrequirementsregardingreliability,efficiency,precisemanufacturingofgears,bearing,etc.Inaddition,thelatestachievementsinthefieldsoftechnologyandtestingoftheprecisenessofmanufacturinggears,bearings,etc.,havebeenappliedtothemanufacturingprocess.
Thedevelopmentofthecomputertechnology,togetherwiththecorrespondingcomputerprograms(AutoCAD,SolidWorks,CATIA,etc.),haveveryquicklyfoundtheirplaceinthedevelopmentoftheexpertsystemforgearboxdesignatahightechnicallevel.Thus,itcanfreelybesaidnowadaysthatthegearboxdesignisnolongera“routinejob”,whichinmostcasesbaseduponthedesigner’sexperienceandknowledge.
Thispaperdemonstratestheapplicationofanonlinearmulticriteriaoptimizationmethod,withthepurposetobuildsuchapowerfulmethodasamoduleintothegearboxdesignexpertsystem.Theintroductionofsomecriteriaconsideringthedesirableperformances,combinedwithhighqualitygearboxcomponentmodelingrepresentsasignificantsteptowardstherealityofageartrainmodel.
2.Gearboxdecomposition
Gearboxesrepresentcomplexmechanicalsystemsthatcanbedecomposedintothecorrespondingnumberofgearswithcorrespondinginteraction.Thismeansthattheprocedureformultistagegearboxoptimizationcanalsobecarriedoutthroughthe
correspondingnumberofstages.Duringthefirstoptimizationstage,characterizedbycomparativelysmallnumbervariables,thedistributionoftransmissionratiopergearboxstagesisdefinedfromtheconditionsoftheminimalvolumeofthegearsets.Duringthesecondstage,themulticriteriaoptimizationproblemissolvedbyintroducingagreaternumberofcriteriawhichrepresenttheessentialgearboxperformances.Thereby,itisnecessarytosatisfytherestrictionsfromthefollowingaspects:
loaddistribution,stresses,kinematicsandcorrectconjugategearaction.
Thetargetfunctionformultistagegearboxrepresentingthevolumeofthegearsetscanbewrittenintheformthefollowingrelation[1]:
f(x)=0.25πd13jI((1+uI2)+jIId32/d12jI(1+uII2)+...)
(1)
where:
uI,uII–thetransmissionrationforparticulartransmissionstagesofmultistagegearbox;d1,d3–diametersofkinematicscirclesofthedrivergears;j=b/d1–ratioofwidthofthegearanddiameterofthedrivergearkinematicscircle.
Forthetargetfunctionstated,itisalsonecessarytodefinethefunctionalrestrictionsfromthestandpointofthesurfacestrengthforthefirststageofgearing,
whichcanbewritteninthefollowingform:
G(x)=Z·[(2·K·T1)/d13]·(U1+1)/U1≤[SH]1/SH
(2)
and,fromthestandpointofthevolumestrength:
g``(x)=K·Y·(2T1)/(Ψ1·d12·m1)≤[Φf]1/SF(3)
Intheexactlyanalogousway,thefunctionalrestrictionsfromthestandpointofthesurfaceandvolumestrengthforothertransmissionstagesofgearboxesaredetermined.
Commencingfromthetechnicalrequirementconcerningthetransmissionratioofagearbox,itisalsonecessarytodeterminethefunctionalrestrictionintheformoftheequation:
h1(x)=u-u1·u2·u3·…·u(n)=0(4)
Basinguponthedeterminedtargetfunctionandtherestrictions,itcanbenoticedthatthisproblembelongstothefieldofnonlinearoptimizationwiththerestrictionsintheformofinequalities.Forthesolutionofthisproblem,thecomputerprogramSUMT,basedonthemixedpenaltyfunctions,hasbeenapplied.Fig.1showsagraphicrepresentationoftheresultsofthecomputerprogramSUMT.Basinguponthesectionofthecorrespondingfunctions,thedomainsoftheoptimumtransmissionratiosforthemultistagegearboxesaredefinedinthefollowingway:
Figure.1:
Therelationbetweenthevolumeofgeartrain
andoverallgearratio.
Tocompletethisanalysisofdecomposedgearbox,hereareaddedapairofrestrictionsintheformofinequalities,basedonstressrestrictions:
-toothgearstressforIstagegear
-tooth-rootgearstressforIIstagegear
Basedongearstressrelationsthevalueofgearmoduleisdeterminated:
-forcontactstress
-forcontactstress
Fig.2showsgraphicalinterpretationofrelations(7)and(8)infunctionoftoothnumberZ1.UpperoftwolinesontheFig.2presentsvaluesofgearmoduledeterminatedoncontactstressandloweroneforvaluesdeterminatedontooth-rootstress.ThelinesandadmissiblespaceonFig.2.indicatethatcontactstressrelationforgearmodule(7)ispriorandistobeusedforgeardimensionsdermination.
Figure.2:
Diagramofmodulevaluesuptotoothnumber
3.Gearsmodeling
Gearsareveryimportantmachineelementstodayandtheyarecommonusedindifferentkindsofgearboxesandtransmissions.Especiallycylindricalgearsaremostapplicablebecauseoftheirveryhighefficiencyandnotcomplicatedproduction.Modelingofcylindricalgearsisveryimportantprocessinmachinedesign,asformakingrealmodelofgearbox,suchforgearandtransmissionstructureanalysisand
optimization.LastyearsthisprocesscanbedoneveryfastandqualitativeusingnewsoftwaretoolssuchasCATIA.Thissoftwareisverycomplex,butsomemainmoduleslikePartdesignandAssemblydesignareinuseforcylindricalgearmodeling.Themainprobleminanygearsmodelingistodefinearealgeartoothandafterthattoimportitintogearbodymaking.Cylindricalgearsmodelingconsistsofseveralphases,dependsfromgearbodyandkindofitsproduction:
Thefirstphaseofgearmodelingisdefinitionandmakingrealinvolutegearteethprofile.
Thesecondphase,incaseofcuttingorpressedgearbody,istousePartdesignCATIAmoduletomakegearbody.
Thethirdphase,onlyincaseofweldingwaymadegearbody,istouseAssemblydesignmoduletoconnectallitsparts.
Allthisphasesconsistsofseveraloperationsanditwillbedescribedseparatelyinfollowedchapters.Everychaptergivesprincipalfactsofgeneralmodeling,somespecialoperationswithadvantagesofusingCATIAsoftwareingearsmodelingandexamplesofdifferentcylindricalgearsthataremodeled.
Inanalysisofinternalandexternalgearprofilestherearefourdifferentlinesinonepitch,whichdefinescompleteprofileofgear.Sotherearetheinvoluteprofile
arc,profilefootcirclearc,addendumcirclearcandtrochoidarcasaconnection[4].Inanalytic-kinematicswayforprofiledefinitionistodefinealotofrestrictionsandconstrainsforsettingparameterequationseachofthisprofilearcsandangles.Aftersomematrixtransformationsmatrixparameterequationforcontactlineofengagedgeartoothprofilescanbede-terminated.Basedonthisanalytic-kinematicsmodelcomputerprogramisdevelopedtodefinepointsofgearprofiles[5].
Gearsmodelingisveryusefulandimportant,astomakerealgeartransmissionsimulation,soforlotofotheranalysis.Differentsoftwaretoolsareinusetodayformachinedesignandmachineelementsmodeling,asACAD,MechanicalDesktop,ProEngineerandlastyearsSolidWorks,CATIAetc.Butitcanbeseenthatgearmodeling(especiallyinternalgears)withrealprofilesismorecomplicatedcomparedwithmodelingofallothermachineelements.HerewillbepresentedthepossibilitiesofcylindricalgearsmodelingusingCATIAV5R11software.DependsofproductionwayandformofgearbodyitispossibletousePartdesignmoduleorAssemblydesignmoduleofCATIAsoftware.
Fordesigningsimplestcylindricalgear(flat)firststepistodefinecorrectsketch,whereinvoluteprofiletoothcoordinates(fromfirstphase)shouldbeimported.After
thatdesignercanapplySketchbasedfeatures(Createpad),togetcutedgearmodelasisshownatFig.3.
Figure3:
Simplestmodelofcylindricalgear
Onestepforwardisdesigningapressmadegearbody,thatcouldbemodeledbyrotatingscatchmadefigure,orlikesimulationofproductionprocess.OnFig.4itisgivenagearmodelmadealsobyusingscatchandfewSketch-Based,Dress-UpandTransformationFeatures.Presentedgearsarecommoninuseandtheyhaveanexternalinvoluteprofile.Butinsomecases,likeplanetarygeartraindesigning,itisnecessarytomakeamodelofinternalprofiledgear.Forthispurposedesignerhastocalculateanewtablewithinvoluteprofilecoordinates,byusingexternalgearasatoolformakinginternalprofile.Afterthatproperlysketchandotherfeaturesasforothercylindricalgearsmodelinghastobe
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- 机械 毕业设计 英文 外文 翻译 变速箱 优化 设计 传动 部件 建模