液压泵可靠性短时试验方法研究

液压泵属于高可靠长寿命产品,其可靠性对整机的可靠性和工作性能有着至关重要的影响,即使经过长时间的加速寿命试验仍可能出现无失效的情况,给液压泵可靠性评估带来了困难。针对传统的可靠性评估局限性,以容积效率退化数据为基础,应用非线性最小二乘法和最优化理论进行液压泵性能参数退化轨迹研究,提出了液压泵可靠性短时试验方法,将短时试验与可靠性寿命试验特征参数对比,证实了该方法的准确性和有效性。

Short-time Test Method of Reliability for Hydraulic Pumps

Hydraulic pumps belong to high reliability and long life product, its reliability has a critical influence on the reliability and performance of whole machine. After a long accelerated life test, it may still be non failure for high reliability and long life products, which makes it difficult to assess reliability. Aiming at the limitation of the traditional reliability assessment techniques, the reliability of the hydraulic pumps short time test method was proposed, which based on performance degradation theory to predict the reliability and residual life of products. To establish residual life prediction model for hydraulic pumps, based on the volumetric efficiency data, the nonlinear least square method was adopted to fit time series, simultaneously, the optimum path search algorithm was built to select the best degradation path. The consistency check of the data in prediction model and the step stress reliability life test were done by using non parametric statistical theory, and the overall sample life distribution function was constructed with Monte Carlo numerical simulation method. The results show that the simulation data of fault sample distribution are consistent with step stress reliability life values. Comparing the test parameters curves of the short term test with step stress accelerated life test, the correctness and feasibility of the short time test method are further verified.