Preparation And Tribological Performance Of Magnetic Brake Shoe For Mine Hoisters

The mine hoisting system is like the throat of coal mine production and brake apparatus is a indispensable important component of mine hoister just as the last and the key security assurance equipment. The tribological performance of brake shoe as the important part of brake apparatus, which has a significant impact on the mine production and people’s life, has the direct bearing on safe operation of mine hoisting system. Therefore, exploring a new kind of brake shoe with good friction and wear properties has important implications for the reliability and safety of mine hoisting system.In this article, magnetic powder was utilized to make traditional brake shoe for mine hoister modified in order to prepare a new magnetic brake shoe and friction and wear rules and mechanism were studied. Firstly, Nd Fe B and nano-Fe3O4 powder were choosed as magnetic powder and nano-Fe3O4 powder was applied to surface modification with KH590, then studing the preparation and performance testing methods of magnetic brake shoe for mine hoister. Secondly, the experimental optimal formula could be attained through the uniform design of the formulation and evalution methods including grey relational analysis, analytic hierarchy process and fuzzy comprehensive judgement. Thirdly, three performance indicators including skewing and stability of friction coefficient and wear rate were treated with data processing, based on which mathematical models could be solved and the theoretical optimal formula could be attained. Experimental study on friction and wear properties of the optimal formulation were implemented via simulating the working environments of the mine hoister. Lastly, tribological experiments, magnetic testing and microstructure and ingredient analysis were carried out to study the action mechanism of magnetic powder and the effect rules of different content of Nd Fe B on friction and wear properties of magnetic brake shoe for mine hoister. The results proved that the mixed magnetic powder could improve the friction and wear properties of brake shoe for mine hoister, which could completely adapt the actual extreme working conditions of mine hoister.