Řešení dynamiky dopadové stolice s impaktními tyčemi na pásovém dopravníku rypadla KU 300

Abstract

The PhD thesis deals with problems of dynamics of the impingement stand with impact bars of a belt conveyer of the KU300 excavator. It focuses on the proposal of a technological solution for reducing the punctures of conveyer belts used on gigant excavators transport routes and long-distance belt conveying. The main problem is the belt demage caused by the rock blocks impingements. Its solution can significantly influence the transport economy in quarries as the present expenses on the transport routes are about 350 millions of crowns per one year. The introductory part of the thesis contains a summary of the impingement stand design solutions used in open pit mines nowadays. Next the mathematical model of the rock impingement on the stand equipped with impact bars is presented. To apply the model, it was necessary to find out the damping coefficient of the dampers placed under the transversal ribs supporting the impact bars. It required to perform the measurements of damping parameters of the rubber dampers with disc springs which are used to attenuate the stand vibrations. In the next part, the thesis concentrates on computational simulations with the goal to investigate behavior of the impingement stand. The stretching force of the belt conveyer needed as one of the input parameters of the developed mathematical model and the stand oscillations to verify the simulation results were measured during the operating regime of the digging-wheel excavator KU 300/30 in the Bílina open pit mine. The following measurements carried out on the KU 300/30 excavator having a classical impingement stand enable to evaluate behavior of the new stand design with the impact bars and to compare it with the traditional roller variant. In the last part of the thesis there are compared results obtained by the simulations using the developed computational model with those acquired by the oscillations measurements on the impingement stand with the impact bars during the excavator operation.