Grounding specific pressure distribution law of track of road-header under yaw cutting conditions

Considering that the grounding specific pressure of roadheader determines the roadheader’ s traffi-cability and working stability,and is the basis of determining the adhesion moment between roadheader and ground,this paper studies the distribution of grounding specific pressure under the condition of yaw cutting of the roadheader. Firstly,the yaw condition of roadheader is analyzed,and the contact parts and load components between roadheader and roadway floor are determined. SolidWorks model is used to determine the center of gravity coordinates of the roadheader under different working conditions,and Cftool fitting tool is used to fit the existing data,and the fitting curve (surface) of the center of gravity coordinates of the roadheader with yaw angle and longitudinal angle is obtained. The formula of specific pressure distribution of roadheader caterpillar grounding is deduced considering the different longitudinal and transverse angles of cutting section,the inclination angle of roadway and back support load. Taking EBZ300 roadheader made in China as an example,a numerical calculation is carried out. The results show that the maximum grounding specific pressure is 0. 312 MPa,which exceeds the average grounding specific pressure of 0. 198 MPa calculated in EBZ300 roadheader specifications. It verifies that the commonly used calculation method of average grounding specific pressure can not truly reflect the distribution of grounding specific pressure. The sway of the cutting section results in the center of gravity deviation,which makes the grounding specific pressure of the caterpillar on one side of the bias greater than that on the other side. The grounding specific pressure distribution law of roadheader crawler on both sides under the influence of different parameters is obtained. The model machine of roadheader is made according to the similar proportion,and the influence of the change of yaw angle and pitch angle of cutting section on the distribution of specific ground pressure of caterpillar track is verified by the model machine. The ground specific pressure distribution of the roadheader crawler under these two working conditions is basically the same as that of the calculation results,and the error is less than 20% . The feasibility and validity of the theoretical calculation method are verified by experiments.