Development Of Self-closing Water-medium Hydraulic Brake Of Coal Shearer

The shearer brake is an important device to ensure the safe and stable operation of the shearer.It is an important part of the shearer.Disc hydraulic brakes currently in use use spring pressure braking and hydraulic pressure release.The following problems exist in the use of the brake:(1)The degree of wear of the friction pair is measured through the measuring hole of the rear cover of the brake.Due to the poor working conditions of coal mining,the staff cannot normally replace the friction pair,which may cause excessive wear of the friction pair and reduce the reliability of the brake.(2)The working medium used in the brake is hydraulic oil,and oil leakage will cause environmental pollution.Does not meet the requirements of energy conservation and environmental protection.(3)The disc structure brake has poor heat dissipation performance.In order to improve the reliability of the brake,improve the heat dissipation performance of the brake and the impact of leakage on the environment.The paper proposes and develops a self-closing water-medium hydraulic brake for coal shearer.The brake uses an environmentally friendly water medium with good heat dissipation performance.When the friction pair wear exceeds the standard,it can automatically lock and improve the reliability of the brake.The main research work of the paper is as follows:(1)In view of the existing problems of hydraulic brakes of coal shearers,technical requirements for automatic locking of water medium hydraulic brakes are proposed.Research and determine the overall design of the brake.The hydraulic transmission control technology is used to determine the automatic locking structure of the brake,and the influence of the automatic locking structure on the performance of the brake is analyzed.(2)Analyze the characteristics of hydraulic transmission of water medium,analyze the problems such as sealing,lubrication,rust prevention,and cavitation after adopting water medium in the hydraulic transmission system of brake,and propose solutions.(3)Research and analysis of the internal temperature field distribution of the brake.Through the establishment of a three-dimensional structure model and the use of finite element software,the temperature field distribution law under emergency braking conditions and continuous braking conditions is studied.The empirical formula for the temperature change of the friction pair along the radial position change is obtained,which provides a theoretical basis for measuring the internal temperature of the brake prototype.(4)Prototype performance experiment test,design brake fluid inertia simulation test bench,refer to "MT2149-2011 Coal Shearer Brake Technical Conditions",design prototype experiment plan,carry out pressure resistance,static braking torque,Experimental tests on dynamic braking torque and braking noise have proved that the various indicators of the R&D prototype meet the relevant requirements.