Experimental study on rock fragmentation mechanisms using a transverse-insert wide-tooth roller cone bit

For increasing the drilling efficiency of roller cone bits in hard rock, This paper suggested a transverse-insert wide-tooth roller cone bit for hard rock based on the disc drill bit’s mechanism for breaking rock and the traits of the tooth material and tooth fixation of the inlaid roller cone bit. Designed and manufactured a new type of tungsten carbide wide-tooth, conducted impact resistance tests on both the wide-tooth and wedge-shaped tooth. The frontal impact resistance of the wide-tooth was 50% higher than that of the wedge-shaped tooth; Conducted single-tooth rock-breaking tests, ring-tooth rock-breaking tests for both the wide-tooth and wedge-shaped tooth. The results showed that the breaking work ratio of wide teeth was reduced by 31.37%, the dynamic load coefficient decreased by up to 57.8%, and more continuous crushing pits were formed; Conducted indoor drilling experiments, the transverse-insert wide-tooth roller cone bit continuously acts on the bottom hole formation, Its unique tooth arrangement creates inter-row rock ridges that undergo brittle spalling, achieving a disc-cutter-like rock fragmentation mechanism. This design increases rock-breaking efficiency by 57.14%, providing a viable solution for high-performance drilling in hard rock formations.