1.There are three kinds of mechanical methods of drilling rock: impact, rotation and rotating impact.
2.Impact drilling: give a impact force to drill bit of the rock surface , under which the drill bit cuts into and breaks the rock.
3.Rotating rock drilling:give a torsional force and a fixed axial force to the drill bit, which moves forward in spiral shape and breaks the rock.
4.Rotating impact rock drilling: give a torsional force and an intermittent axial force to the drill bit so that the drill bit and the rock surface are drilled into the rock at a certain inclination angle.
