Experimental study on the adaptability of cutters with different blade widths under hard rock and extremely hard rock conditions.

To investigate the matching rules of cutters with different blade widths in hard rock and extremely hard rock environments, this study carries out a full-scale cutting test of 432-mm disc cutters with blade widths of 12 mm, 19 mm and 30 mm. A multifunctional cutter performance experimental system was used to test the cutting loads and rock-breaking quantity of rust stone granite (hereinafter referred to as hard rock) and granite (hereinafter referred to as extremely hard rock) as well as to analyse the specific energy consumption for rock breaking under different cutting parameters. The experimental results show that (1) the blade width has a greater influence on the normal force than on the rolling force. The rock-breaking resistance of the 12-mm-blade-width cutters under extremely hard rock conditions is 36.7% lower than that of conventional cutters. (2) Under the same conditions, the smaller the blade width is, the smaller the specific rock-breaking energy consumption is and the smaller the optimal cutter spacing is. Under extremely hard rock condition, the specific energy consumption of the 12-mm-blade-width cutters is 37.9% lower than that of conventional cutters. (3) With a certain gross thrust of a single cutter, the rock-breaking quantity of a single 12-mm-blade-width cutter is much larger than that of the 19-mm-blade-width cutter, regardless of the types of rock. Under extremely hard rock conditions, the S/P of the 12-mm-blade-width cutter with the highest rock-breaking efficiency is approximately 10–12. [ABSTRACT FROM AUTHOR]