【摘要】 针对重型机床液压系统故障频繁且多与油液中的固态颗粒污染物相关的问题,进行了油液污染趋势变化试验。通过时域分析获得了油样颗粒数的有量纲和量纲一参数,通过Q-Q图和K-S检验分析有量纲参数,污染颗粒数是退化量服从正态分布的退化数据。进行了油液污染与环境相关性分析试验,采用相关系数法分析得到,颗粒数变化量与一定范围内的温度、流量、压力的相关性小;将液压元件分为管路、阀、过滤器三类,用直径5μm左右的颗粒和直径大于15μm的颗粒分别研究管路及阀件的堵塞和磨损情况,以过滤器过滤精度大小的颗粒研究过滤器的堵塞情况,设定ISO4406标准20/17级对应的颗粒数为阈值,利用退化量分布建立了液压元件单一故障模式的可靠性模型;利用竞争失效模型将上述模型融合为多故障模式下的可靠性模型。更多还原

【Abstract】 The failures of heavy-duty machine tool was mainly on the hydraulic systems and caused by oil contamination. Aiming at the problems, the trend change tests of oil contamination were carried out. After the time domain analysis on test data of oil samples, the dimensional and non-dimensional parameters of particle numbers was obtained. Through the analysis by Q-Q plots and K-S tests on dimensional parameters, it might be seen that the degradation data of contaminated particles obeyed the normal distribution. The correlation test of oil contamination and the environment have been carried out. Analyzed by using correlation coefficient method, the change values of oil contamination were hardly dependent of temperature, flow rate and pressure. Hydraulic components were summarized into three categories, pipelines, valves and filters. The blockages of pipelines and valves were studied by the particle number with diameter about 5 μm. The wears of pipelines and valves were studied by the particle number with diameter larger than 15 μm. The blockages of filters were studied by particles with similar diameter with filtering accuracy. The threshold of the particle number was set according to the 20/17 level of ISO4406 standard. Reliability models of various components for a single failure mode were established based on the distribution of degradation amount. The reliability model under multiple failure modes was fused by the competitive failure model.更多还原