Slip safety of inclined scraper conveyor under the load coupling effect of coal mining machine

Aiming at the problem that the scraper conveyor in the steeply inclined working face is prone to sliding instability and causing safety accidents under the coupling load of the shearer, a safety mechanics analysis of sliding was carried out to provide quantitative theoretical support for the anti-sliding safety control of the equipment. By combining theoretical modeling, numerical simulation and experimental testing, a load transfer model of the shearer cutting and a sliding mechanics model of the n-segment series scraper conveyor were established. The force balance equation of a single middle trough and the critical criterion for the overall sliding of the system were derived. The EDEM and RecurDyn co-simulation was used to analyze the influence of key factors such as two coal and rock strengths of 1.2 MPa and 2.6 MPa and working face inclinations from 30° to 60° on the sliding characteristics of the scraper conveyor. A 1:5 scale dynamic load sliding test bench was built, and the dynamic load of the shearer was simulated by a shaker. The rationality of the theoretical model was verified through multi-condition tests. The results show that the shearer load acting section is the weak force section between the sections of the scraper conveyor. When there is no hydraulic support restraint, as the working face inclination increases from 30° to 60°, the force between the sections of the shearer acting section increases from 150 N to 350 N, with an increase of 133 %. At a 45° inclination, the sliding driving force of the shearer acting section has exceeded the maximum static friction force in the unrestrained state, and there is a risk of local sliding, but the overall system remains stable. After applying the hydraulic support restraint force, the force between the sections of the shearer acting section at a 60° inclination decreases by more than 48 %, and the maximum static friction force of the acting section can completely counteract the sliding driving force, eliminating the risk of local sliding and achieving the overall sliding stability of the scraper conveyor. The research reveals the sliding instability mechanism of the scraper conveyor under the coupling load of the shearer, clarifies the key parameters for sliding safety control, and provides important theoretical and experimental basis for the anti-sliding safety design and on-site control of the scraper conveyor in steeply inclined working faces.