Research On Steering Modes For Cantilever Type Roadhesder

Cantilever type roadheader is one of the most important equipments in coal mine,and its steering performance has a direct impact on the excavation work and the stability and reliability of the whole machine.In this paper,the cantilever type roadheader we research on has no rack roller structure which is different from the traditional four wheels and one belt construction.Supported by Virtual prototype technology,this paper do research on dynamic simulation of the travel mechanism of tracked vehicle of EBZ-135roadheader.The main contents are as follows:1. Theoretical calculation(1) According to the empirical parameters,this paper deduces the resistance force of the travel mechanism of tracked vehicle when roadheader going straight.(2) Introducing the lateral eccentricity and longitudinal eccentricity,the paper deduces the ground pressure distribution when tracked vehicle’s center of gravity overlaps with the chassis’s geometric center or not.(3) Based on the ground pressure distribution,this paper derives each track’s resistrance torque when the travel mechanism of trackd vehile steering stably,and then get the total resistrance torque of the chassis.(4) Analysis the force distribution of each track when the travel mechanism of tracked vehile use one track brakeing,two tracks rotating to the opposite direction and two tracks moving in the same direction at different speeds to steer,the paper calculates the analytical formula of driving force and power of the driving wheel when the chassis steering stably.2.Dynamic simulation(1) This paper using the Pro/E software establishs the mainly parts’ models:driving wheel,guiding wheel,walkframe as well as the crawler board,and then assembles into the whole machine.(2) Simplify the3-D assembled model and export from Pro/E by parasolid format when there is no interference,then import the model into Adams/View.According to the actual situation,add appropriate constrains and loads,and apply the contact force using cmd command.The virtual prototype of roadheader is established successfully when the model has no error through the self-text.(3) Research on simulation of roadheader’s virtual prototypeWe set the pavement as loose road and solid road. The paper carries on different dynamic simulations on the pavement:one track brakes,two tracks rotate to the opposite direction and two tracks move in the same direction at different speeds.Then we get resistance torque changes of the chassis and the driving force and power of the driving wheel.3.Comparison and analysisWe compare the calculated value with simulated value.if the error is big,it is necessary to modify the corresponding coefficient and obtain the relationship between the coefficient of rolling resistance and steering resistant coefficient after correcting the coefficient which validates the paper’s algorithm and simulation correctness.This paper’s research provides the foundation of total dynamic simulation of EBZ-135roadheader and it has a theoretical reference value for optimization and improvment of travel mechanism of tracked vehicle which has no rack roller structure.