【作者】 石莹；

【导师】 江亲瑜；

【作者基本信息】 大连交通大学 ， 机械制造及其自动化， 2013， 博士

【摘要】 机车牵引齿轮作为机车传动装置的核心部分,其力学行为和工作性能对机车运行状况都有重要影响。随着铁路向着高速、重载方向发展,对机车牵引齿轮的承载能力和传动速度提出了更高的要求,而载荷和速度又是影响机车牵引齿轮材料摩擦学性能的主要因素,因此考虑摩擦学影响因素进行机车牵引齿轮力学性能研究对我国机车车辆的发展具有非常重要的现实意义。在相当多有关齿轮摩擦学性能的研究中,齿轮啮合过程中轮齿表面的摩擦学性能通常被近似处理为稳定不变,或是套用经验公式求得。然而机车牵引齿轮传动是相当复杂的动力学过程,啮合表面间载荷、速度均随时间而变化,因而齿面的摩擦学性能也是实时变化的。本文在详细分析国内外关于齿轮摩擦学相关研究的基础上,以某机车牵引齿轮为研究对象,考虑载荷和速度等因素对材料摩擦学性能的影响,对机车牵引齿轮力学性能进行系统深入的研究。本文主要研究内容及研究成果有：(1)以某机车牵引齿轮为研究对象,针对其所用材料42CrMo和17CrNiMo6,在摩擦磨损试验机上模拟实际工况进行销盘往复摩擦磨损试验,获得不同载荷、速度下的摩擦系数。对试验数据进行多元非线性回归分析和显著性检验,考虑摩擦面间载荷和速度等因素影响,获得机车牵引齿轮材料摩擦系数公式。并通过多组随机试验验证公式的正确性。(2)基于所得的机车牵引齿轮材料摩擦系数公式,考虑载荷、速度的影响,对试验摩擦副接触应力进行理论和有限元仿真计算,所得结果相符；考虑载荷、速度的影响,对试验摩擦副进行温度场仿真分析,仿真值和试验值相符。结果表明：复杂非线性的摩擦磨损问题可以利用有限元仿真方法进行模拟,从而为材料摩擦学性能研究提供一种实用而且有效的方法。(3)考虑机车牵引齿轮啮合过程中齿面接触压力、相对速度不断变化所导致的接触点摩擦学性能的时变性,在机车启动和持续运行两种工况条件下对机车牵引齿轮进行应力场仿真分析,得到接触应力、摩擦应力的变化规律。对比考虑摩擦和不考虑摩擦两种情况下齿轮齿根弯曲应力,结果表明齿面摩擦力对齿轮力学性能影响显著,有必要从摩擦学角度对机车牵引齿轮进行研究。(4)对机车牵引齿轮进行稳态温度场仿真分析,研究啮合齿面摩擦热流量的分布规律以及齿面稳态温度值的分布规律；考虑啮合过程中载荷、速度不断变化所导致的摩擦热流量的变化,在不同啮合位置上定义瞬态的移动摩擦热源,研究各啮合节点瞬时温度分布及变化规律。为齿轮表面温度计算提供一种更加准确的方法。更多还原

【Abstract】 As a core of the locomotive transmission, the mechanical behavior and working performance of the locomotive traction gears have an important influence on the running state of the locomotive. Since the development of railway transportation is towards the heavy duty and highspeed, people have higher demands for the load-carrying capacity and transmission velocity of the locomotive traction gears. The load and velocity are the important factors which affect the tribological properties of materials for the locomotive traction gears. Therefore study on the mechanical properties of the locomotive traction gears based on tribology has an important realistic meaning on the development of the locomotives and rolling stocks in China. In many researches of the tribological properties for gears, the tribological behavior of gear materials in the meshing process is treated to be stable or is obtained by empirical formulas. Howerve, the locomotive traction gear transmission is a quite complicate dynamics process; the velocity and load of tooth surface are changed with time. Therefore the tribological properties of the meshing surface of gears are real-time.Based on the detailed analysis of the domestic and foreign studies on the gear tribology, considering the influences of load and velocity on the tribological properties of materials, the mechanical properties of the locomotive traction gears are researched systematically and deeply. The main researches and achievements are as follows:(1) Taken a certain locomotive traction gear as the research object, aimed at the materials42CrMo and17CrNiMo6, the pin-on-disk reciprocating friction and wear test which simulates the factual condition is done on the tribometer test machine. The friction coefficients under different loads and velocities are obtained. The test data are conducted by using multivariate nonlinear regression and significance test. Considering the influence of the load and relative velocity between the friction surfaces, the friction coefficient expression of the locomotive traction gear materials is obtained. The correctness of the friction coefficient expression is proved by groups of random tests.(2) Based on the obtained friction coefficient expression of locomotive traction gear materials, considering the effect of the load and velocity, the theoretical and simulation calculations of the contact stress for the test friction pair are conduct. The simulation results agree with the theoretical results. Considering the effect of the load and velocity, the temperature field of test friction pair is analyzed. The simulation results agree with the test results. It is found that complex and nonlinear friction and wear problem can be simulated by the finite element method, which provides a practical and effective way for the research of material tribological properties. (3) Considering the time variation of the tribological properties for the meshing point which is caused by the change of the contact force and relative velocity in the meshing process, the stress field of the locomotive traction gears under the starting and continuous running condition of the locomotive is analyzed and the variation laws of the contact stress and the friction stress are obtained. Through comparing the bending stresses on teeth root of the gear with friction and without friction, it is found that the influence of friction force between teeth on the mechanical properites of the gears is significant and it is necessary to research the locomotive traction gears from the tribological viewpoint.(4) The steady temperature field of the locomotive traction gears is analyzed. The distribution laws of the friction heat flux and the stable-state temperature on the meshing tooth surface are researched. Considering the change of the friction heat flux which is caused by the variation of the load and velocity in the meshing process of the gears, the transient and movable friction heat sources of different meshing position are set. The transient temperature distribution and variation law of every meshing node are researched, which provides a more accurate method for the calculation of the gear surface temperature.更多还原