液压泵可靠性短时试验方法研究

As a kind of high reliability hydraulic components, hydraulic pump has a long service life, it is hard to get its failure data by life test or accelerated life test. Therefore, assessmenting and enhancing reliability of key pieces of equipment with high reliability and long service life, like hydraulic pump, has become an important technical problem to be solved in the field of Engineering. Based on life prediction and reliability assessment of hydraulic pump, this project put forward a short-time test method by analyzing the time-varying flow of hydraulic pump. In this project, the life prediction model of hydraulic pump based on regression theory which considers volumetric efficiency as performance parameter is built. We solve the optimization problem of tightening censoring threshold and find out the best sampling period of short-time test by using time series method, determine the fitting criteria between test data and parent data, build the reliability evaluation system of short-time test based on the law of performance degradation of hydraulic pump. In the meantime, we research visualization technology of reliability data assessment, compile the data-fitting, evaluation, inspection and optimization module, build a data processing system for short-time reliability test of hydraulic pump. The technical solution of this project can improve and enrich the reliability test theory for hydraulic components, reveal underlying pattern of performance degradation (attenuation) to achieve reliability growth, reduce the length and cost of test substantially. For the reliability test of component and system with high reliability and long service life, this project has direction significance for theory and practice.

液压泵属于液压系统中高可靠长寿命的核心元件，一般很难通过常规的寿命试验和加速寿命试验获得失效数据，因此评定与增长以液压泵为代表的高可靠长寿命关键基础零部件的可靠性成为工程领域亟待解决的共性技术问题。本项目拟开展液压泵寿命预测和可靠性评定研究，提出以时变流量为特征信息的液压泵短时试验方法，基于回归理论构建以容积效率为性能参数的液压泵寿命预测模型，通过时间序列法解决短时试验采样周期和紧缩截尾阈值的优化问题，给出短时数据与母体数据一致性的检验准则，建立基于性能退化规律的液压泵可靠性短时试验体系。同时，研究短时数据可视化技术，构造数据拟合、评价、检验和优化模块，创建液压泵可靠性短时试验数据处理系统。本项目研究可以丰富和完善液压可靠性试验内容，揭示潜在性能退化(衰减)过程以实现可靠性增长，大幅缩短试验周期和降低试验代价，对于高可靠长寿命且试验费用昂贵产品的可靠性试验具有理论和工程意义。

液压泵是液压系统的核心动力元件，广泛地应用在工业液压和行走液压领域。液压泵的可靠性对整机的可靠性和工作性能有着至关重要的影响。目前，液压泵可靠性试验技术在军事、航空、航天等领域研究较多，而在工业液压和工程液压领域研究为之甚少。为此，该项目结合工程实际，针对民用液压泵开展可靠性试验研究，并提出短时试验方法。.本项目针对可靠性试验功率大、耗时长的特点，设计了基于功率回收技术的液压泵可靠性试验方案，并对其加载原理和功率回收效果进行了分析。采用步进应力加速寿命试验的方法对4台样本进行可靠性试验，通过逆矩估计法，获得了液压泵可靠性特征参数曲线。.最后，以容积效率退化数据为基础，采用非线性最小二乘法对容积效率数据和时间序列拟合，通过最优退化轨迹求解算法获得液压泵性能参数的退化轨迹方程，构建液压泵剩余寿命预测模型。采用非参数统计理论对预测寿命和全寿命数据作一致性检验，并结合蒙特卡洛数值仿真的方法对总体寿命分布函数进行统计推断。并进一步验证短时试验方法的正确性。