装载机驱动桥主减速器疲劳可靠性的研究

发布时间：2019-01-16 08:18

【摘要】：装载机是工程机械中的主要设备，在建筑、道路、矿山、码头等生产中起到极重要的作用。装载机在长期使用中，疲劳失效是其主要的破坏形式。主减速器作为装载机传动系统的关键部分，其核心部件螺旋锥齿轮受到交变载荷（包括齿根弯曲应力和齿面接触应力）的作用。因此主减速器极易出现疲劳失效导致装载机不能正常工作。所以，开展对装载机主减速器疲劳可靠性的研究对提升装载机质量档次、服务工程实际具有主要意义。本文以ZL50轮式装载机驱动桥主减速器为研究对象，采用动力学测试和有限元分析相结合的方法对其疲劳可靠性进行了研究。主要研究内容及结论如下： 1）对ZL50轮式装载机驱动桥主减速器进行了动力学测试，得到了扭矩-时间历程，然后利用梯度门限检测法和标准方差检测法检测并剔除了测试数据中的异常峰值，最后选取载荷历程极差的5%为门限值剔除了无效幅值。 2）分析了主减速器的主要失效模式，，得出主减速器的主要失效部位在一对螺旋锥齿轮，主要失效原因是齿面接触疲劳失效和齿根弯曲疲劳失效；对螺旋锥齿轮进行了有限元接触分析，并依据计算结果分析了锥齿轮的接触状态以及失效模式，提出在预估主减速器疲劳可靠度时，应主要考虑主从动锥齿轮在单齿啮合状态下的齿面接触疲劳失效和从动锥齿轮的齿根弯曲疲劳失效。 3）采用雨流法对锥齿轮应力-时间历程计数得到相应的载荷谱数据，然后分析了正态分布、对数正态分布、威布尔分布对载荷谱的拟合程度及其对疲劳可靠性的影响。研究表明：选用拟合程度最高的分布函数对载荷谱进行拟合，可以有效减少在预测结构可靠度时由统计方法造成的误差。 4）根据统计结果计算了主减速器的应力分布函数和强度分布函数，然后采用应力-强度干涉模型估算了主减速器的疲劳可靠度，最后依据Miner线性疲劳累积损伤理论估算了锥齿轮的疲劳寿命。本文来源于浙江省科技厅重大科技专项项目（2009C11111）“轮式装载机驱动桥关键技术研究与产业化”。
[Abstract]:Loader is the main equipment in construction machinery. It plays an important role in construction, road, mine, wharf and so on. Fatigue failure is the main failure form of loaders in long-term use. As a key part of the drive system of loader, the main reducer, the spiral bevel gear, is subjected to alternating load (including tooth root bending stress and tooth surface contact stress). Therefore, the main reducer is prone to fatigue failure and the loader can not work properly. Therefore, the research on the fatigue reliability of the main reducer of the loader is of great significance to improve the quality and service engineering of the loader. In this paper, the fatigue reliability of ZL50 wheel loader drive axle main reducer is studied by means of dynamic test and finite element analysis. The main research contents and conclusions are as follows: 1) the dynamic test of the main reducer of the drive axle of the ZL50 wheel loader is carried out, and the torque-time history is obtained. Then gradient threshold detection method and standard variance detection method are used to detect and eliminate the abnormal peak value in the test data. Finally, the invalid amplitude is eliminated by selecting 5% of the extreme difference of load history as the threshold value. 2) the main failure modes of the main reducer are analyzed. The main failure part of the main reducer is a pair of spiral bevel gears. The main failure reasons are tooth surface contact fatigue failure and tooth root bending fatigue failure. The finite element contact analysis of spiral bevel gear is carried out, and the contact state and failure mode of the bevel gear are analyzed according to the calculated results, and the fatigue reliability of the main reducer is estimated. The tooth surface contact fatigue failure of the main driven bevel gear and the bending fatigue failure of the tooth root of the driven bevel gear under the condition of single tooth meshing should be considered. 3) the bevel gear stress-time history was counted by rain flow method to obtain the corresponding load spectrum data, and then the fitting degree of normal distribution, logarithmic normal distribution and Weibull distribution on the load spectrum and its influence on fatigue reliability were analyzed. The results show that fitting the load spectrum with the distribution function with the highest fitting degree can effectively reduce the error caused by the statistical method in predicting the structural reliability. 4) according to the statistical results, the stress distribution function and the strength distribution function of the main reducer are calculated, and the fatigue reliability of the main reducer is estimated by using the stress-strength interference model. Finally, the fatigue life of bevel gear is estimated based on Miner linear fatigue cumulative damage theory. This paper comes from the important Science and Technology Project (2009C11111) of Zhejiang Science and Technology Department, "Research and industrialization of key Technology of Wheel Loader Drive Axle".
【学位授予单位】：浙江理工大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH243

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