Cutting roller

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Schrämwalzendenkmal in Schmelz (Saar) .

A cutter roller is the roller-shaped tool carrier of a roller cutter loader . The tools of the cutter are chisels made of hard metal and are arranged on the cutter in clockwise and counter-clockwise helical lines. The roller is located at the end of the roller support arm and is usually driven hydraulically .

Roller types

There are two types of roller, the cylindrical roller and the globoid roller. In the case of the cylinder roller, the screw threads are placed vertically on a roller body. This roller body, the core tube, is made cylindrical or frustoconical. The globoid roller has a frustoconical core tube and a helical pitch that increases continuously towards the discharge side. The spaces between the screw threads are elliptical or semicircular. This construction reduces the friction of the pile .

Dimensions and drive power

Cutter roller in the mining museum

A large number of parameters must be taken into account in order to optimally match a cutter roll to a deposit. The dimensions and design of the cutting rollers depend on the conditions of the seam . The thickness of the seam has the greatest influence on the dimensions of the roller wheel. The thicker the seam, the larger the roller diameter must be. There are rollers with diameters from 0.75 meters up to 2.3 meters. With these rollers, cutting heights of 1.8 meters to a maximum of five meters can be achieved. The width of the roller wheels also depends on the seam thickness; wider roller wheels are usually used for lower seams. Roller wheel widths of 0.8 meters are most commonly used. Either tangentially arranged round shank chisels or radially arranged flat chisels are used as chipping bits. Which type of chisel is used depends on the cuttability of the coal and that of the adjacent rock. Depending on their size, the roller wheels have drive powers of 150 to 450 kilowatts, the roller speeds are 37 revolutions per minute.

Working method

In the case of cylindrical rollers, the mineral loosened by the cutting bits collects first in the spaces between the roller body. The further rotary movements shift the material in the axial direction of the roller and discharge it. The clearing volume remains constant with this type of roller. In the case of cylindrical rollers with a frustoconical core tube, there is a slight increase in volume on the discharge side. In the case of cylindrical rollers, material jams often when cutting, which means that the loading capacity of the rollers is impaired. In addition, larger lumps of coal or stone can get jammed between the screw threads of the roller, which hinders the removal of the debris. Globoid rolls work in a similar way to cylinder rolls. However, due to their design, globoid rollers have a better loading capacity than cylindrical rollers, since with these the clearing volume on the discharge side is steadily increasing. This means that there is no material jam. The rounded shape between the screw threads of the roller also prevents chunks of material from jamming.

Individual evidence

  1. ^ Walter Bischoff , Heinz Bramann, Westfälische Berggewerkschaftskasse Bochum: The small mining dictionary. 7th edition, Verlag Glückauf GmbH, Essen, 1988, ISBN 3-7739-0501-7
  2. ↑ a b c Gerhard Hebel, Walter Hemmer, Frank Lemmes: The use of cutting rollers with falling cutting. In Glückauf 21, 1986 ( memento of April 29, 2014 in the Internet Archive ) (retrieved from Archive org. On January 11, 2016)
  3. ↑ Plant construction Krummenauer: Globoid cutting roller (accessed on September 14, 2011)
  4. ↑ Heinz Kundel: coal mining. 6th edition, Verlag Glückauf GmbH, Essen, 1983, ISBN 3-7739-0389-8

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