accident frequency
8.causes for high accident frequency in coalmines were analyzed and countermeasures were pointed out. Conclusion shows that strengthening the research on basic hazard theory, particularly on the identification and control of the third kind of hazard, is very helpful to the improvement of safety management in coalmines.
9.If the actual number is larger than the percent 20 of the static load, this can enhance the abrasion between electric motor and the others parts in drive section. In the same time this can enhance accident frequency of thechain in the actual work and influence the working performance of the conveyor.

