Abstract: Based on the running status of gear box and the character of oil monitoring,the method was proposed which combine fuzzy comprehensive evaluation with Analytic Hierarchy Process(AHP).By extracting the indicators of the quantifier of wear particle and physical and chemical analysis, establish the comprehensive evaluation index system;using entropy weight method and AHP to determine the subjective and objective weight,then the combination weighting was obtained in multiplicative integration method.The membership function was established between aim level and the second level of evaluation,and use the membership of weighted to come ture comprehensive evaluation.Applying the distance analysis method to determine the overall conclusion,and then get the final evaluation result by relative degree.By means of the monitoring to experiment unit which was constructed by ourselves,the evaluation result consistent with the fact status,and then validating the comprehensiveness and rationality of this method.

Key words: gear box, oil monitoring, wear particle, physicochemical analysis, fuzzy comprehensive evaluation