Working Principle of the Roller Bit Drilling Rig
A Tricone drill bit consists of three smaller drill heads, each with many hard alloy teeth. When the drilling rig is in operation, the entire Roller Bit rotates with the drilling rod, which is referred to as the “revolution.” Each small roller head also rotates on its own axis, meaning the roller bit has both self-rotation and revolution. Additionally, there is a pressurizing mechanism at the top of the drilling rod that applies significant vertical downward pressure, often several tens of tons.
Under this vertical pressure, the hard alloy teeth of the roller bit are pressed into the rock, causing local fracture. The hard alloy is pressed into the rock, and the roller bit rotates and revolves, causing the rock between the teeth to experience shear forces. This shear action further grinds and fractures the rock. Thus, the Rotary Tricone Drill Bits use both axial pressure and rotational motion to crush the rock through compression, grinding, and shear forces, which is a mechanical fracturing process.
The image shown is a domestic roller bit drilling rig, model KY-310. The “310” refers to the most common diameter of the Tricone Drill Bit used with this rig, which is 310 mm. This drilling rig has various components such as the drilling rod, rod frame, lifting cylinders, platform, walking mechanism, drill bits, jacks, dust purification systems, and the rotating pressure car. This rig is called a “high-rotation” roller bit drilling rig.
Compared to percussion drilling rigs, the biggest advantage of roller bit drilling rigs is the longer drilling rods, which can exceed 9 meters each. With two rods, the total length reaches 18 meters, which is sufficient for most mining operations. In contrast, the drilling rods of percussion rigs are generally shorter, requiring more rod replacements to drill to the same depth, which reduces efficiency.
The image here shows the drilling tools for the roller bit rig, including Milled Tooth Tricone Bits. The torque is composed of four main parts: the drilling rod, rod stabilizer, shock absorber, and the roller bit, such as Insert Tooth Drill Bits.
Although the rig appears to be a single unit, it consists of many smaller parts, with the hard alloy teeth being the most critical. The back of the roller bit also features hard alloys, such as those found in Tungsten Carbide Tricone Bits, to improve wear resistance. The TCI Tricone Drill Bits shown in the image have been used in mining for some time, and the hard alloy teeth have significantly worn down. If these bits are used longer in this state, drilling efficiency is severely reduced. In such cases, the bits must be replaced, or the hard alloys can be replaced to restore functionality.
Additionally, small holes on the drill bit connect to the hollow center of the drilling rod, which provides an air passage. When drilling, rock debris is generated, and if it is not removed in time, the bit will repeatedly grind against the rock, greatly reducing drilling efficiency. This also increases wear on the bit and shortens its lifespan. Therefore, high-pressure air must be used to expel the debris from the hole. The drilling rod is smaller in diameter than the hole, creating a gap to expel the debris.
With continuous technological advancements and improvements in mining techniques, the roller bit drilling rigs, especially those using Hard Rock Tricone Bits and Water Well Tricone Bits, are bound to evolve into more efficient, intelligent, and environmentally friendly machines. We believe that Soft Rock Tricone Bits and other innovations will play an even more critical role in future mining operations, leading to even more remarkable achievements.