基于光谱分析的重载车辆变速箱可靠性评估方法研究

润滑油光谱分析是变速箱磨损状态监测的重要手段。以某重载车辆变速箱台架试验中润滑油原子发射光谱分析得到的元素成分含量检测数据为基础，通过相关性分析和磨损机理分析确定了能够反映整机磨损状态和失效特点的金属元素，并对补油、换油后的光谱检测数据进行了修正，将变速箱试验过程中特征金属元素的含量随试验时间的变化规律表示为线性函数的形式。然后，综合考虑检测数据的时序规律与离散性，利用不同时刻光谱检测数据的正态分布均值和标准差进行变速箱可靠性评估，进一步讨论了失效阈值对可靠性评估结果的影响。研究表明，重载车辆变速箱润滑油中的Cu元素浓度与其他金属元素浓度的相关性较高、绝对值较大，既能够反映变速箱整体磨损状态，又便于检测，利用多个试验样本的润滑油Cu元素浓度光谱检测时序数据，可以对重载车辆变速箱进行可靠性评估;若失效阈值取定值，则失效阈值越大，同一时刻变速箱的可靠度越高;若失效阈值取随机分布，则失效阈值的离散度越大，可靠度随时间延长而降低的趋势越缓慢。当可靠度R大于0.9时，失效阈值的均值对可靠性评估结果的影响十分显著，同一时刻变速箱的可靠度随失效阈值标准差的增大而降低。将光谱分析与概率统计学结合进行变速箱可靠性评估方法研究，扩展了光谱分析技术的应用范围，具有创新性。

Study on the Reliability Assessment Method of Heavy Vehicle Gearbox Based on Spectrometric Analysis

Spectrometric oil analysis is of great importance for wear condition monitoring of gearbox. In this context, the contents of main elements compositions in the bench test of heavy vehicle gearbox are obtained by atomic emission spectrometric oil analysis first. Then correlation analysis of the test data and wearing mechanism analysis are carried out to get the metal element which could be used to describe the wearing and failure of the gearbox. The spectrometric data after filling/changing oil are corrected, and the laws of the contents of main elements compositions during tests are expressed as linear functions. After that, the reliability assessment is executed with considering the degradation law and discreteness of test data, in which the mean and standard deviation of normal distribution of spectrometric oil data at each time point are adopted. Finally, the influences of the threshold are discussed. It has been proved that the contents of metal element Cu, which is got by spectrometric oil analysis of different samples, could be used to assess the reliability of heavy vehicle gearbox. The reason is that the metal element Cu is closely related to the general wear state of gearbox, and is easy to be measured. When the threshold of Cu content is treated as a constant, bigger threshold means higher reliability at the same time, and the mean value of threshold has significant impact on the reliability assessment results as R>0.9. When the threshold is treated as a random variable, bigger dispersion of threshold means smaller slope of reliability against time, and also means lower reliability of gearbox as R>0.9 at the same time. In this study，the spectrometric oil analysis and probability statistics are used together for the reliability assessment of gear box, which extends the application range of spectrometric analysis.