Conical selections of mining equipment with enhanced utility characteristics: specific technological and construction elements

• Jishan Zhang

  English

  Author

mineral deposits, especially hard coal, and for drilling roadways in underground mines, tunnels and other 
underground buildings in civil engineering. As the primary working process of this type of machines, 
mechanical mining of rocks is carried out by cutting. These machines' working units are equipped for this 
purpose with picks, usually conical (point-attack). They have the form of an axially symmetrical body consisting 
of a steel shaft and a tip usually made of tungsten carbide, connected by a hard brass solder. Due to the possibility 
of spontaneous rotation in the pick holders and even wear and tear of their tip around the entire perimeter, conical 
picks have a much longer service life compared to radial picks. Their life, especially when cutting hard and 
sharp abrasive rocks, is, however, still unsatisfactory. Rapid wear of the picks leads to a decrease in mining 
efficiency, an increase in this process's energy consumption, and an increase in dynamic surplus to which the 
cutting machine is subject. Among many forms of wear and tear of the conical picks, attention was paid to the 
problem of asymmetrical abrasive wear of the tips, pulling out the connection of the soldered pick tip and fatigue 
breaking of the pick shafts in the transition zone of the shank into the shoulder. The article presents original 
propositions of modification of the construction of the roadheaders/shearers conical pick shafts and the method 
of fixing the tip in the pick shaft in order to increase their operational durability significantly. The technologies 
and devices necessary to manufacture conical picks of the proposed structure were described. The developed 
modifications significantly contribute to the improvement of functional properties, including the reliability of 
conical picks, used in particular for hard rock mining.

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