Karaganda State Technical University, Karaganda, Kazakhstan:

S. K. Malybaev, Professor, Doctor of Engineering Sciences
N. S. Malybaev, Associate Professor, Candidate of Engineering Sciences
S. O. Frolova, Magister, svetlanka92best@mail.ru

The analysis of operation of the main belt manufactured by H+E Logistic GMBH, Germany, in the Nurkazgan mine, Kazakhstan, has revealed offsetting from the center of driving drums. To prevent the offsetting, the lower conveyor flight is equipped with double rollers installed at an angle relative to each other, which results in breakage of the rollers and damage of the belt. The alternatives of the belt seating on the rollers are analyzed, the forces in the belts are determined, and the limiting angles of the side rollers to ensure flat adherence of the belt are evaluated. It is found that the belt conveyor operated in the Nurkazgan mine has its lower rollers mounted at an off-standard angle, which leads to the considerable wear and causes their failure. For the specific operating conditions, depending on the type of the belt, the determination procedure is developed for the maximum allowable angle of the lower flight roller. The case-studies of the transverse instability of belts up to its complete stoppage are examined. One of the main problems of the transverse stabilization of belts is reduction of the belt escapement from the drums under disturbing forces whch affect the belt along the entire rout of the conveyor, and due to misalignment of axes of the drums. The belt escapement brings wear and decomposition of edge surfaces owing to friction on metal structures of drive and tighting ends; furthermore, upon the belt escapement on the tail drums, spills are observed at the point of loading and along the route of the conveyor. The problems of determining centering force and transverse motion of the belt on the drums are considered, and it is revealed that the belt escapement on the drums is only governed by the nature of deformation of the entering branch, and the values of the belt escapement on the neighbor drums are unrelated. For the transverse stability of the belt, the type and number three-roller and chain cartridges are recommended with regard to operating conditions of the conveyor. The research findings and the recommendations delivered are approved by Karagandatsvetmet for introduction.

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