Neue gewinnungsorgane für schrämlader

New cutting drums for longwall shearers, designed for the extraction of moderately and hard to mine coals are presented in the paper. They are characterized by a varying distance between the pick tips located in the cutting line and the axis of rotation of the longwall shearer. A new pick layout on the lateral area of the drums makes it possible to adjust the number of picks in contact with the extracted coal to the haulage speed of the shearer. This way, a remarkable increase in the depth of cut at lower haulage speeds can be obtained. The executed tests show that the use of the new drums results in a considerable reduction in the specific energy consumption in comparison with the units produced with conventional shearers.