Mining roller bits are mainly used for vertical drilling operations in large open-pit mines, earth and rock excavation, water wells, and geothermal wells. During the drilling process, the roller drill drives the roller bit to rotate through the drill rod while applying downward thrust for drilling. Under the action of rotational force, the three rollers, equipped with hard alloy teeth or arranged steel teeth, rotate around their respective tooth claw shafts, while axial thrust embeds the alloy or steel teeth into the rock surface, using a combination of extrusion and shear forces to break the rock, thus achieving the purpose of drilling..

Mining roller bit

The design of the bit must adapt to the characteristics of the rock to be drilled, and different design structures should be adopted for roller bits used on different types of rocks.

Common alloy shapes for Swedish mining roller bits

    Mining roller bits require a significant thrust during the drilling process, so the strength and structural design of the bearings are very high. Large diameter bits generally use a roller-ball-roller (RBR) bearing system, while smaller diameter bits use a roller-ball-slide (RBF) bearing system. The radial forces generated during drilling in these two bearing systems are mainly borne by the large roller bearing load, while the small roller or sliding bearing plays a supporting role, and the axial force is mainly borne by the flat thrust bearing at the front end. As the drilling hole deepens and the bit wears, the axial force is also transmitted to the rear thrust bearing and ball bearing, extending the service life of the bit.

a-Roller-Ball-Roller (RBR) bearing system

b-Roller-Ball-Sliding(RBF)Bearing system

Swedish roller bit bearing system