To study the rock breaking principle of the cone bit, start with the analysis of its motion law. According to the number of cones on the drill bit, cone bits can be divided into single cone bits, two cone bits, tricone bits and four cone bits, among which tricone bits are mostly used. The speed distribution laws a and b are the implicated speed and relative speed of the point shadow on the outer edge of the drill bit; c and d are any point X on the contact generatrix of the drill bit or cone and the bottom hole (relative to the direct D of the drill bit and the direct of the cone E) The implicated speed and relative speed, H is the speed of the tooth against the rock.

According to the number of cones on the drill bit, cone bits can be divided into single cone bits, two cone bits, tricone bits and four cone bits, among which tricone bits are mostly used. The consistent movement of the drill bit assumes that the free-standing drill bit rotates at a constant angular velocity (the bit and the cone) on a flat and rigid bottom of the well (the cone does not eat into the rock), and the pressure is distributed evenly on the generatrix of the contact surface between the cone and the bottom of the hole.

Tri-cone bit is a bit that is widely used in petroleum drilling and has strong drill bits manufacturers applicability. The breaking action of the tri-cone bit on the rock at the bottom of the well is closely related to its motion law. Therefore, the actual movement speed of any X point on the contact generatrix of the bit and the bottom hole should be this

The vector sum (speed) of the speed at which the shop grows with the drill bit Yudong and the speed produced by the shop with the rotation of the cone. Due to the frictional resistance of the bottom hole rock against the bit teeth during the movement of the rotor, the bit roller must rotate in the opposite direction when the bit advances.The tri-cone drill bit is a drill bit that is widely used in petroleum drilling and has strong applicability.