Simulation And Experimental Study Of The Combined Brake System For A Tracked Vehicle

Dry multi-plate friction brakes are widely used on tracked vehicles due to their large braking torque,simple structure and easy installation.However,there are also common problems such as heat decay and friction loss.Therefore,it is necessary to equip auxiliary brakes such as eddy current retarders to form a joint system,which could reduce friction brake wear,ensure braking stability and reliability,and also ensure driving safety.This article takes a certain type of tracked vehicle combined braking system as the research object.The combined braking system（including two independent braking systems of dry multi-plate mechanical brake and eddy current retarder）is studied theoretically,modeled,simulated,and tested.Research was carried out in three areas,the specific contents are as follows:1.Theoretical innovation analysis and modeling simulation of the existing dry multi-plate brake（mechanical brake）of a certain tracked vehicle.The first is to establish the force transfer function of the ball pressurization mechanism.The second is to introduce the rough contact theory-GT model to build a model of the brake friction plate engagement process.Then the model simulation calculation is performed to obtain the braking torque characteristic curve.To increase the power from 7000N to 13000N is taken as an example,the calculated braking time at different initial speeds is reduced by an average of 39%,and the braking effect is significantly improved,the conclusion provides a direction for the design of the mechanical brake operating method of tracked vehicles.2.Analyze and model the working principle of the eddy current retarder.Focus on the simulation of the two important structural parameters-the number of exciting coil turnsand the air gap spacing7)₀ and their impact on the braking torque.Finally,the retarder braking process was simulated and the conclusion was drawn:High working current can significantly improve the braking effect.The research provides reference for the design and brake control of eddy current retarder.3.A mechanical-eddy current retarder emergency combined braking and speed segmented combined braking method are proposed,and a combined braking speed curve is obtained by simulation.An emergency combined braking time_{（6） and an energy consumption ratio of the eddy current retarder which defined as0}value are proposed,the two values is evaluation indexes to evaluate the effects of the two types of combined braking.The calculated values of₀)are over 70%,which verifies the reliability of the combined braking system and the effectiveness of the braking method.The conclusion provides important reference and guidance.4.The bench test was performed using the high-performance braking system test bench constructed by the research group,and the inertia braking tests were performed on the mechanical brake and the eddy current retarder respectively.The braking speed curve was consistent with the theoretical simulation,which verified the simulation model’s effectiveness.The inertia braking test of the speed-segment combined braking system was carried out.The results showed that the energy consumed by the eddy current retarder accounted for more than 70%of the initial kinetic energy,which was consistent with the theoretical model simulation results,which verified the reliable braking characteristics of the combined braking system and the effectiveness of the speed segmented combined braking method,which provides an important test reference for a certain type of tracked vehicle to equip combined braking system.