Effect of angle of wrap on cutting performance of drum shearers and continuous miners

The significance of angle of wrap in tool-lacing has, to date, been investigated in detail on the loading efficiency of shearer drums only; no comprehensive work on the cutting efficiency has, however, been found. This paper is concerned with the effects of angle of wrap on the cutting performance of rock and coal cutting picks fitted on drum shearers and continuous miners. A series of laboratory trials was carried out at full-scale, to simulate the actual cutting position of the picks in a cutting sequence at varying angular positions, which correspond to the angle of wrap. The results showed that the tool forces varied remarkably with the changes in the angular position, in such a way that all exhibited a minimum at 10degrees angle, being more pronounced for the sideways force components. It was also inferred that cutting drums, which operate at higher advance per revolutions, might experience poor performance due to higher tool forces if greater angle of wraps are employed.