Research On Preparation And Tribological Properties Of Resin Based Brake Shoe Material For Mine Hoist

The disc brake is an important safety protection device for the mine hoist.The friction braking torque between the brake shoe and the brake disc directly affects the safety of mine hoist.The high-speed and heavy-duty working conditions in deep wells lead to high-speed and large-pressure braking processes,which puts higher requirements on the tribological properties of brake shoe material.Therefore,the preparation of a high friction performance of the mine hoist resin-based brake shoe material is of great significance to ensure the safety and reliability of mine hoist in deep wells.According to the similar principle theory,a friction brake test rig capable of developing high-speed and large-pressure brake conditions is built;Based on the existing brake shoe material formula,combined with uniform test design method(UD),fuzzy comprehensive evaluation(FCE)and analytic hierarchy process(AHP),the basic brake shoe material formula with excellent mechanical properties and tribological properties is obtained.The thesis adds new fillers such as graphene,carbon fiber and glass fiber to the basic brake shoe material formula,and explores the influence of different new fillers and three new filler blend ratios on the mechanical properties and tribological properties of brake shoes,and obtains optimized formula brake shoes material;Comparative analysis of the mechanical properties and tribological properties of the self-made formula brake shoe material and the existing typical WSM-3 brake shoe materials are made;The friction brake test brig was used to investigate the influence of braking parameters(brake specific pressure and initial braking speed)on the tribological performance of self-made optimized brake shoe materials.The results show that the basic formula quality ratio was 9.8% for phenolic resin,3.8% for nitrile rubber,4.9% for vermiculite powder,2.6% for conductive carbon black,10.6% for ceramic fiber,3.8% for graphite,8.7% for sepiolite,19.2% for wollastonite,10.6% for barium sulfate,7.9% for diatomite,1.5% for stearic acid,4.5% for zircon,3.8% for mica,3% for kaolin,3% for antimony trioxide,and 2.3% for lead oxide;The addition of graphene,carbon fiber and glass fiber fillers generally improves the mechanical properties and tribological properties of the brake shoe material;The formula of the basic formula and 4% graphene,2% carbon fiber and 4% glass fiber is the optimal brake shoe material formula;The friction coefficient of the self-made optimized brake shoe material is higher than that of the two WSM-3 brake shoe materials,and the volume wear rate is between the two typical WSM-3 brake shoe materials;The increase of the initial braking speed leads to the law of decreasing-increasing-decreasing friction coefficient;An increase in the brake specific pressure causes a decrease in the friction coefficient;The stability of friction coefficient of self-made optimized brake shoe material is better under 12 groups of emergency braking conditions.