【作者】 屈文涛；

【导师】 沈允文；

【作者基本信息】 西北工业大学 ， 机械设计及理论， 2006， 博士

【摘要】 双圆弧齿轮传动比渐开线齿轮传动具有承载能力高、寿命长等特点，在石油、化工、矿山、冶金等行业得到了广泛应用。在新型井下驱动双螺杆泵中，实现两个螺杆同步运转和功率分流的双圆弧齿轮是决定泵工作能力的关键部件。泵挂深度超过1200m、沉没度超过500m(双螺杆泵整体浸泡在原油中)、井底温度超过80℃、设备不间断工作30个月、同步齿轮箱内充满润滑油、动力系统运转速度3000r／min左右、传递功率45kW，同时由于井筒空间限制，泵体直径≤140mm，且润滑油得不到更换和补充，狭小的空间又不利于散热等非常规工况条件又对双圆弧齿轮的工作能力提出了更高的设计要求。本文的主要研究内容为：(1)分析了双圆弧齿轮跑合前的齿廓方程，建立了有限元接触计算在静止状态和运动状态下的分析模型。并计算讨论了双圆弧齿轮的接触、弯曲强度；测试了齿轮弯曲应力以验证接触模型的正确性。(2)研究了双圆弧齿轮跑合仿真计算的基本原理，以ANSYS接触算法为子程序建立了双圆弧齿轮跑合仿真模型，对一对双圆弧齿轮进行了跑合仿真以预测所采用的跑合措施的效果，并与跑合前的计算结果做了比较。(3)针对双圆弧齿轮传动系统，通过划分热网络节点，建立了热网络方程；研究了有润滑条件下的功率损失、热阻及对流换热计算模型，确定了不同部件的对流换热系数；计算了各节点在不同润滑条件下的温度值及轴承、齿轮等摩擦副零件的热变形量。(4)建立了无油润滑条件下轴承、齿轮等关键部件的功率损失和对流换热计算模型，确定了传动系统瞬态计算模型；研究了系统温度分布和变化规律并计算了摩擦副零件的热变形量。5)在热弹耦合理论的基础上，应用ANSYS软件，计算了双圆弧齿轮在热弹耦合场环境中跑合前和跑合后的耦合变形、耦合应力，并利用离散干涉检查算法实现了变形后双圆弧齿轮的运动干涉检查，提出了最佳侧隙。(6)根据热弹耦合计算结果，为反映双螺杆泵的实际运转工况，编制了全寿命历程载荷谱，完成了双圆弧齿轮疲劳寿命预测，并与同尺寸渐开线齿轮寿命进行了比较。主要研究成果及创新点如下：1．以热弹耦合状态下双圆弧齿轮跑合前后接触强度、变形及跑合后疲劳寿命为工作能力评价参数，基于齿轮啮合原理、轮齿接触分析、摩擦学、传热学和疲劳寿命分析等理论，将有限元、热网络、碰撞干涉检查和雨流计数等方法相结合，提出了一种非常规工况条件下双圆弧齿轮传动工作能力研究新方法。2．分析了影响建模的因素和边界条件、载荷处理方法，基于柔性轮缘和ANSYS／LS-DYNA建立了双圆弧齿轮动态接触应力分析用柔性体齿轮接触模型。3．基于数值齿面思想，利用ANSYS软件中的参数化语言APDL建立了双圆弧齿轮跑合接触仿真模型，模拟其跑合过程并得到了跑合后接触应力分布。4．基于热弹性力学和离散碰撞干涉算法，提出了双圆弧齿轮热弹耦合状态下运动干涉检查模型，完成了运动干涉检查，为齿轮动态设计奠定了基础。5．变潜油电机额定工况为双螺杆执行机构实际运转工况，利用雨流计数法对双圆弧齿轮的随机载荷数据进行了处理，编制全寿命历程载荷谱，预测了非常规工况条件下双圆弧齿轮的疲劳寿命。更多还原

【Abstract】 A double circular arc gear drive has the characteristics of higher carrying capacity and longer life than an involute gear drive, which is widely used in the petroleum, chemistry, mining, metallurgy industries. In a newly down-hole driven twin-screw pump, the double circular arc gears, which make the twin-screws run simultaneously and realize power split, are the key components in determining the working capacity of a pump. Meanwhile, better design requirements about higher working capacity of a double circular arc gear are needed under such abnormal working conditions as the setting depth of the pump beyond 1200m, the submergence depth over 500m that immersed a twin-screw pump in the crude oil, the temperature of the bottom of a well above 80℃, 30 months of uninterrupted work, full of lubricant in the synchronous gear box, a rapid power system at a speed of 3000r/min, 45 kW of transfer power, a body diameter of the pump less than 140mm, the lubricant unable to replace or renew, the space too small to disperse the heat, etc.This thesis lays emphasis on the following points:(1) The tooth profile equations of a double circular arc gear before the running-in are analyzed, and the contact computation models with finite elements under the static status and the dynamic status are set up. Moreover, the contact strength and the bending strength of the double circular arc gears are calculated, and the bending stress is tested to verify the contact model.(2) The fundamental about the running-in simulation of a double circular arc gear is studied, and its model is set up on the basis of ANSYS contact arithmetic. Furthermore, the running-in simulation of a pair of double circular arc gears has been realized to predict the effect of the running-in method, and the simulation results have been compared with the computation results before running-in.(3) By dividing different heat nodes and meshes, the heat net equation is determined. The computation models of power loss, heat resistance and heat convection with the lubrication are discussed, and heat convection coefficients of different parts are presented. Furthermore, the temperature of all nodes under the different lubricating conditions and the thermal deformation of the friction parts, such as bearings and gears, are calculated. (4) The computation models of power loss and heat convection of key parts, such as bearings and gears, without any lubrication, are established, and the transient computation model of the drive is determined. In addition, the distribution and changing rule of the temperature of the system are investigated, and the thermal deformations of a friction pair of parts are calculated.(5) Based on the thermo-elastic coupling theory and ANSYS, the coupling deformation and the stress of a double circular arc gear in the thermo-elastic coupling field, before and after the running-in, are computed. By the discrete interference inspection arithmetic, the moving interference inspection of the double circular arc gears after deformation is carried out, and the best backlash is presented.(6) To demonstrate the real working condition of the twin-screw pump, and on the basis of the computation results of thermo-elastic coupling, the full life history of loading spectrum is compiled, the prediction of the fatigue life of the double circular arc gear is implemented, and its life is compared with that of the involute gear drive at the same size.The major innovative points and results are as follows:1. Based on the theories of gear geometry, gear tooth contact analysis, tribology, heat transmission and fatigue life analysis, and combined with the methods of finite elements, heat net, collision interference inspection and rain flow counting, a new method on studying the working capacity of a double circular arc gear under abnormal working condition is put forward by taking contact strengths and deformations before and after running-in, and fatigue life after running-in, of a double circular arc gear under thermo-elastic coupling status as the evaluation parameters of working capacity.2. The factors of influenced modeling, boundary conditions and the method of load processing are analyzed, and the contact model of a flexible gear to analyze the dynamic contact stress of a double circular arc gear is established on the basis of the flexible rim and ANSYS/LS-DYNA.3. On the idea of a numerical tooth flank and utilized APDL of ANSYS, the running-in contact simulation model of a double circular arc gear is constructed, the contact stress distribution after running-in is obtained by the simulation of running-in course.4. Based on the thermo-elastic mechanics and the discrete collision interference arithmetic, the moving interference inspection model of a double circular arc gears under thermo-elastic coupling status is presented, and a moving interference inspection is carried out, which is served as a theoretical basis to the dynamic design of a gear.5. To change the rated condition of a submersible electric motor into the working condition of a twin-screw and utilize the rain flow counting method, the random load data of double circular arc gear are processed The full life history of loading spectrum is compiled, and the fatigue life of double circular arc gear drive under abnormal working condition has been predicted.更多还原