Dynamic characteristics of chain drive system under blocking condition of scraper conveyor based on DEM-MBD

The scraper conveyor is a crucial component in mining equipment, operating in extremely challenging conditions that frequently lead to blocking faults. To investigate the dynamic characteristics of the chain drive system under blocking conditions, a coupled model of the scraper conveyor was developed using the discrete-element method (DEM) and multi-body dynamics (MBD). This model integrated fault analysis to explore how the chain drive system behaved under various blocking forces and positions along the scraper. From the perspective of scraper attitude, it was observed that the farther the blocking position was from the center line of the scraper, the greater the yaw angle of the blocked scraper became. This change in yaw angle results in significant differences in chain ring tension: near the scraper blocking side, the tension can be up to 54.8 times that of normal working conditions, whereas on the side farther from the blocking point, it can reach up to 14.9 times. Importantly, the chain ring tension near the scraper blocking side correlated positively with the distance from the blocking position to the scraper's center line, while tension on the side farther from the blocking position showed a negative correlation with this distance. Additionally, the maximum head torque under blocking conditions can increase up to 34.4 times compared to normal working conditions. Finite-element analysis of the blocked scraper revealed that the maximum equivalent stress occurred at the blocking position. The location of the maximum principal stress was influenced by the scraper's structural design, with its magnitude positively correlating with the distance from the blocking position to the scraper center line. These findings highlight the complex interactions within the scraper conveyor's chain drive system under blocking conditions, provides a data foundation for fault diagnosis and design optimization of scraper conveyors, enhancing the safety and reliability of mining operations.