Improving the operational durability of tangential-rotary picks for rock cutting with central spraying and hydrodynamic rotation

This article presents a proposal for a new solution of tangential-rotary picks intended for mining, especially hard rocks with roadheaders. The design of these picks is characterized by many innovative solutions aimed at significantly increasing their service life. The method to achieve this goal is to provide effective central spraying of the ring tip picks, crown picks, or similar types of picks while using the spray water to cause the picks to rotate as they contact the rock being mined. An important element of the work is to conduct extensive simulation studies using FEM to determine the stress distribution in the pick shank subjected to external load from cutting. The new design of the tangential-rotary pick is equipped with a reinforcing sleeve, in which a state of compressive stress is induced. This enables a significant improvement in the fatigue strength of the pick shanks. The conducted FEM comparative tests confirm the accuracy of the adopted design assumptions. They also determine the beneficial value of the tension nut torque, which tightens the reinforcing sleeve located on the pick shank.