Improving design and application method of screening bucket excavators

The purpose of the study is to increase the productivity and economic efficiency of mining operations using screening bucket excavators on the basis of the introduction of a new technical and technological solution that expands equipment functionality. The study involves the analysis of known designs of screening buckets installed on excavators that ensure material separation to be carried out simultaneously with excavation and loading works. It is noted that a promising development direction of screening buckets is a design with working drums. The article presents an excavator with a modernized screening bucket and its operation technology, which allows to start rock mass sorting in the bucket while the excavator is turning to the place of unloading. The improved screening bucket is equipped with a hinged movable bottom controlled by hydraulic cylinders to accumulate fine fractions screened through the working drums. Fine fractions accumulated in the moving bottom are unloaded into a dump truck, after which screening continues directly into the body of the dump truck. Screening finished, the movable bottom closes and the excavator unloads the coarse fractions remaining in the bucket into another vehicle. Unloading is carried out by bucket turning. The combination of screening and excavator turning reduces the operation cycle time, which increases the performance of both the excavator and dump trucks. The use of a modernized screening bucket with a moving bottom eliminates the loss of valuable fine material as a result of spilling when the excavator turns for unloading. The movable bottom can be installed on the screening buckets of known designs and does not require their significant alteration. Application of the proposed technical and technological solution will reduce unit costs and increase the efficiency of work.