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1、Dr.LiuWenpingliuwp@sdu.edu.cn88392850Chapter12Updated13/10/2009,RichardDesignofhelicalgears斜齒輪傳動設計1KeypointsForceanalysisofhelicalgears斜齒輪的受力分析Strengthcalculationofhelicalgears齒輪強度計算公式:應用注意事項、參數(shù)意義21Loadonhelicalgeartoothfrompowertransmitted斜齒圓柱齒輪傳動的受力分析Fn1i
2、nthenormalplane(法面)Pabccanbedecomposedinto3components:Ft1,Fr1andFa1Relationship:31Loadonhelicalgeartoothfrompowertransmitted斜齒圓柱齒輪傳動的受力分析Directionofforces各力的方向判斷Fr,Ft:thesameasthoseofspurgearsFa:Left-andRight-handrules(左、右手定則)fordrivinggearPresentationoffor
3、ces:表示方法Right-handedLeft-handedDrivinggearn1n2drivingFr2Fr1Ft2Ft1Fa1Fa242Contactfatiguestrengthofhelicalgeartooth斜齒圓柱齒輪傳動的接觸疲勞強度Amendmentstotheparameters:1)LengthofcontactlineL接觸線長度Lx:接觸線總長度變化系數(shù)(0.9~1);Zε:重合度系數(shù)若ε?>1,則取ε?=152)HelixanglefactorZ?螺旋角系數(shù)Amendment
4、stotheparameters:Increasinghelixangle?isgoodforgeartoothmeshingaction;thisisbeneficialforreducingthecontactstressbecausethelengthofcontactlinebecomeslonger,andfordecreasingshockloadandvibrationandnoise.6Amendmentstotheparameters:3)Curvatureradiusatthecontac
5、tpoint接觸點曲率半徑--spurgear--helicalgearCurvatureradiusofhelicalgearincreasesandthecontactstressdecreasesaccordinglyP222圖12.16,按螺旋角查取ZH7Calculationformulaforcontactfatiguestrength接觸疲勞強度的計算公式8Notesfortheaboveformula:Contactstrengthcheck接觸疲勞強度校核公式Designformula接觸疲
6、勞強度設計公式9Howtouse?與直齒相同據(jù)β查Ad,由材料系數(shù)修正P226103Bendingfatiguestrengthofhelicalgeartooth斜齒輪彎曲疲勞強度潘存云教授研制潘存云教授研制斜齒輪齒面上的接觸線為一斜線。輪齒的失效形式:?局部折斷Bendingstrengthcheck彎曲強度校核公式Designformula彎曲強度設計公式112)YFaandYSa—canbeobtainedfromP229-2303)Yβ—helixanglefactor螺旋角系數(shù)Comparedwi
7、thspurgears:1)mnseeP23912Comparedwithspurgears:4)Yε—contactratiofactor重合度系數(shù)注意:斜齒輪中,計算接觸應力時的重合度系數(shù)Zε與計算彎曲應力時的重合度系數(shù)Yε不同。前者使用實際齒數(shù)Z,后者使用當量齒數(shù)Zv。斜齒輪接觸應力計算時使用的重合度系數(shù)13Howtouse?與直齒相同14Howtouse?與直齒相同P23215Selectionofdesignparameters設計參數(shù)的選擇1)m,Z,sameasthoseofspurgears2
8、)helixangleβ螺旋角β16Selectionofdesignparameters設計參數(shù)的選擇17Selectionofdesignparameters設計參數(shù)的選擇18THANKSFORLISTENING19