基于摩擦学的机车牵引齿轮力学性能研究

发布时间：2018-11-27 16:47

【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。
[Abstract]:As the core part of locomotive transmission, the mechanical behavior and working performance of locomotive traction gear have important influence on locomotive operation. With the development of railway towards high speed and heavy load, higher requirements are put forward for the load capacity and transmission speed of locomotive traction gear, and the load and speed are the main factors that affect the tribological properties of locomotive traction gear material. Therefore, it is very important for the development of locomotive and rolling stock to study the mechanical properties of locomotive traction gear considering the influence factors of tribology. In many researches on the tribological properties of gears, the tribological properties of gear surfaces are usually treated as stable and invariant during gear meshing, or can be obtained by applying empirical formulas. However, the traction gear drive of locomotive is a very complicated dynamic process. The load and velocity of the meshing surface vary with time, so the tribological performance of the tooth surface also changes in real time. Based on the detailed analysis of domestic and international research on gear tribology, this paper takes the traction gear of a locomotive as the research object, and considers the influence of load and speed on the tribological properties of the material. The mechanical properties of locomotive traction gears are studied systematically and deeply. The main research contents and results of this paper are as follows: (1) the friction and wear tests of a locomotive traction gear are carried out on a friction and wear tester using 42CrMo and 17CrNiMo6, which are used to simulate the actual working conditions. The friction coefficient at different loads and velocities is obtained. The multivariate nonlinear regression analysis and significance test were carried out on the test data. The friction coefficient formula of locomotive traction gear material was obtained by considering the factors such as load and speed between friction planes. The correctness of the formula is verified by a number of random experiments. (2) based on the formula of friction coefficient of locomotive traction gear material, considering the influence of load and velocity, the contact stress of test friction pair is calculated theoretically and by finite element simulation. Considering the influence of load and velocity, the temperature field of the test friction pair is simulated and analyzed, and the simulation value is in agreement with the test value. The results show that the complex nonlinear friction and wear problems can be simulated by finite element method, which provides a practical and effective method for the study of tribological properties of materials. (3) considering the time variation of the tribological properties of the contact point caused by the constant change of the relative velocity and the contact pressure of the tooth surface during the meshing process of the traction gear of the locomotive. The stress field of locomotive traction gear is simulated and analyzed under two conditions of locomotive starting and continuous running, and the variation of contact stress and friction stress is obtained. The results show that the friction force on the tooth surface has a significant effect on the mechanical properties of the gear, so it is necessary to study the traction gear of locomotive from the angle of tribology. (4) the steady state temperature field of locomotive traction gear is simulated and analyzed, and the distribution law of friction heat flux and steady temperature value of tooth surface are studied. Considering the variation of friction heat flow caused by load and velocity during meshing, transient moving friction heat sources are defined at different meshing positions, and the instantaneous temperature distribution and variation law of each meshing node are studied. It provides a more accurate method for calculating the surface temperature of gear.
【学位授予单位】：大连交通大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：U260.332;TH117

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