过滤后润滑油液中磨粒粒度概率分布的研究

Investigation on Probability Distribution of Wear Particle Size in Lubricant after Being Filtered

润滑油中的磨粒是设备失效的一个重要原因。建立了过滤后润滑油液中磨粒粒径概率分布密度函数的数学表达式。计算和分析表明:(1)过滤后润滑油液中所含的磨粒粒径概率分布参数不但与过滤器的性能参数有关,而且与过滤前油液中所含磨粒的粒径概率分布有关,但与过滤前油液中所含磨粒的数目多少无关;(2)过滤后油液中所含磨粒的粒径均值μd和均方差σd均与过滤前油液中所含磨粒粒径概率分布的尺寸参数β大体呈指数关系。μd和σd之值的变化,可以作为反映系统磨损状态的标志;(3)所定义的两个过滤器参数,极限过滤粒径a和敏感系数b与滤后油液中磨粒粒径的均值μd和均方根σd有明确的对应关系。小的a值和大的b值有利于减少油液中磨粒粒径的μd值及粒径在μd值附近的磨粒数。

Wear particles in lubricant arc an important reason to cause machine failure. A mathematical expression for the probability distribution function of wear particles in lubricant after being filtered was formulated. The results show ： （ 1 ） the probability distribution function of wear particles in lubricant after being filtered is determined by the filter＇ s parameters, the probability distribution function of wear particles in lubricant before being filtered, and has nothing to do with the number of the wear particles in the lubricant before being filtered ; （2） the mean value μd and root-mean-square value σd of the particle size in the lubricant after being filtered have approximately exponential relations with the size parameter β of the probability distribution function of the wear particle size in the lubricant before being filtered, which obeys Weibull distribution. So the variation of μd and σd can signify that of the wear state of the tribological system ; （ 3 ） the defined smallest filtering size a and the sensitive parameter b of a filter have a definite relationship with μd and σd , and less a and/or greater b will correspond to small mean value μd and the number of wear particles which size is close to μd.