Design And Research Of Mining Electric Locomotive Braking System

As one of the main tools for coal transportation,mining electric locomotives need to increase their speed in order to improve transportation efficiency.However,the performance of mining electric locomotive braking system directly affects its maximum running speed and transportation efficiency,and the performance of the braking system is directly related to the transportation safety of mining electric locomotive,so it is necessary to design a braking system that is simple in operation,reliable in braking,and easy to automate.Aiming at the problems of complicated operation,long brake air travel and low automation degree of the current mining electric locomotive braking system,a hydraulic anti-lock disc braking system is proposed.Based on the basic technical parameters of 5t mining electric locomotive,the main components of the braking system are analyzed.The feasibility of applying the hydraulic anti-lock disc braking system to the mining electric locomotive is proved.Through in-depth analysis of adhesion mechanism between wheel and rail of mining electric locomotive during braking,the mathematical model of mining electric locomotive anti-lock braking system is established,and its corresponding simulation model is established in MATLAB/Simulink.The change rule of speed,wheel speed,slip rate and braking distance of mining electric locomotive with or without anti-lock braking system is analyzed.The results show that the braking performance of the mining electric locomotives with anti-lock braking system is obviously superior,especially the adhesion between the wheel and rail is fully utilized.It meets the requirements of mine safety regulations for mining electric locomotives braking distance.The speed and braking distance of mining electric locomotives with or without anti-lock braking system under the same conditions are analyzed.The results show that the maximum speed allowed by the anti-lock braking system is 35%higher than the maximum speed allowed by the non-anti-lock braking system under the requirement of mine safety regulations on the braking distance.It can also be said that transportation efficiency of mining electric locomotives has been greatly improved.Based on the low-speed and heavy-load operation characteristics of mining electric locomotive,the transient heat transfer differential equation of brake disc is established through in-depth study of friction theory and heat transfer theory.The finite element model of direct thermo-mechanical coupling of brake disc is established in ABAQUS.The distribution rule of temperature field and stress field of brake disc under anti-lock braking condition is deeply analyzed.The results show that the temperature rise curve of the brake disc surface is serrated,and the temperature rise is faster in the early stage of braking,and tends to be stable in the later stage.The most important thing is that the maximum temperature is lower than 150?,which meets the requirements of the mining electric locomotive braking system.The maximum equivalent stress value is far less than 250 MPa,which meets the strength requirements of the brake disc material.Finally,the method of bench test is selected to verify the correctness of the simulation results of brake disc temperature field,which indirectly proves the correctness of the finite element model of brake disc thermal-mechanical coupling,and thus proves the rationality of the application of hydraulic anti-lock disc brake system in mining electric locomotive from the side.