Study on wear characteristics of single-tooth cutting in coal seams with coal-rock interfaces

Shearer is an important mechanical equipment in coal mining, and wear is the main cause of failure of its picks. The cutting force model for pick-type picks cutting coal seams with coal-rock interfaces was established. A coal-rock cutting test bench was used to carry out single-cutting pick coal-rock cutting tests under various working conditions. Image processing technology and the Kirsch edge detection algorithm were adopted to obtain the geometric data of the wear amount of the shearer picks under impact wear conditions. This study proposes the wear rate of the pick body thickness and the wear length of the pick body as evaluation indices for the wear degree of the cutting picks, collects the mean values of the cut loads under different wear degrees of the cutting picks, and analyzes the effects of factors such as the drum rotation speed, cutting thickness, impact angle, tilt angle, and the position of the coal-rock interface on the damage characteristics and wear amount of the picks. The results show that Kirsch operator exhibited good edge positioning capability and excellent image processing effect, with an accuracy rate as high as 96.5%. When the rock stratum is at position A, the wear amount of the cutting pick is the smallest. When the impact angle is 45°, the inclination angle is 5°, the drum rotation speed is 60–90 r/min, and the cutting thickness is 10–15 mm, the wear amount of the pick can be reduced.