Evaluation Research On Comprehensive Properties Of Bearing Grease Based On The Gray Fuzzy Model

With the current trend towards machinery and equipment downsizing and high-speedy, the comprehensive properties for lubricating grease is requested higher and higher, lubricating grease consists of a wide variety and the quality with good and bad. the existed evaluation method to evaluate the grease comprehensive properties is based on bearing life testing machine, it has disadvantages with long-time consuming and high costs, therefore, the research of how to select out the grease owning the best comprehensive properties rapidly and economically in order to minimize the lubrication costs and promote machinery use efficiency furthest has an important practical significance.At first, this paper focuses on analyzing the lubricating grease performance index and influencing factors of comprehensive properties, based on the requirements of the lubricating grease performance, we choose dropping point, resistance extreme pressure and wearability, colloidal stability, oxidation stability, infiltration degree, protective performance as comprehensive properties evaluation factors of bearing grease. Secondly, according to different influence degree of evaluation factors to bearing grease, this paper adopts combinatorial weighting method to determine weight distribution in the optimization model; using membership function of fuzzy method for reference and grey correlation degree analysis to establish grey fuzzy method to bearing grease comprehensive properties evaluation. Meanwhile, it takes five sets of lubricating grease as examples to compare and optimize on comprehensive properties.The evaluation results of the grey fuzzy model adopting combinatorial weighting method agree with the results of experimental verification on bearing grease very well. It’s results show that combinatorial weighting method can reflect the importance degree of the evaluation factors and the new established model is believable and effective. The model can screen the best comprehensive properties among the five sets of lubricating grease and also provide a new thought and method for screening the lubricating grease on comprehensive properties.