Study on load current characteristics of scraper conveyor under vertical impact

During the operation of the mine scraper conveyor, it is easy to be affected by the uneven movement of hydraulic support and the uneven cutting bottom of shearer, bearing various types of impact, of which the impact in the vertical direction is the most obvious. This phenomenon will lead to serious wear of the transmission system and unbalanced power of the driving motor. In this article, the formation mechanism of vertical impact of scraper conveyor is studied and the running resistance of the scraper conveyor under different vertical impact effects is calculated. The vertical impact simulation model of the scraper conveyor transmission system is established. The load conditions of scraper conveyor under different working conditions of middle slot clearance, convex and concave of middle slot are simulated and analyzed. The simulation results show that when the middle slot clearance increases, the impact between the middle groove and the middle plate will be stronger, and the impact on the drive system of the scraper conveyor will be more obvious. The peak value of load current produced by vertical impact is positively correlated with the degree of concave or convex bending of the middle groove. The maximum bending angle of adjacent middle slots is the main factor determining the sudden peak value of impact load and the load increment after impact stability of scraper conveyor. The impact caused by the convex and concave bending of the middle groove has a maximum impact on the running resistance of about 12%, which is the main factor affecting the motor power imbalance of the drive system. In the coal mining face, the impact load monitoring platform of scraper conveyor is built, and some impact load monitoring experiments under different vertical bending angles are carried out. The comparison results show that different degrees of vertical impact make the load current fluctuate obviously, and in a short time, the peak value of the impact current can reach 1.5 times of the normal working current, causing serious damage to the chain, motor and other parts of the scraper conveyor. The change trend of the motor current curve after impact is basically consistent with the simulation curve, and the average absolute error range is about 0.435A ~ 1.342A, which verifies the correctness and rationality of the vertical impact simulation model of the scraper conveyor. The research results provide a theoretical basis for improving the intelligent control level of scraper conveyor and ensuring the load stability and power balance of coal mine transportation equipment, so as to reduce the transportation cost of fully mechanized mining face and prolong the service life of transportation equipment.