Core Barrel Roller Bit
The single roller bit is used as an accessory, which is installed on the barrel drill alternately. It is mainly used in the pile foundation construction of municipal bridges and buildings, and is mostly used in coastal areas.
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Product Overview
The rock-breaking principle of the rotary barrel drill is to form a broken ring by alternating inner and outer roller bit, then break rocks through extrusion, shearing and impact. Finally, break the rock core in the middle of the barrel bit by oscillating the barrel bit, and form the holes required for the construction after the rock core is taken out.
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Product Overview
The rock-breaking principle of the rotary barrel drill is to form a broken ring by alternating inner and outer roller bit, then break rocks through extrusion, shearing and impact. Finally, break the rock core in the middle of the barrel bit by oscillating the barrel bit, and form the holes required for the construction after the rock core is taken out.
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- Basic structure of single roller bit
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As a component, the single roller bit is alternately installed on the thin-wall shaft to form a rotary driling. Among them, the two and three toothed wheels need to be welded to achieve the full coverage of the broken ring.
The single roller bit is composed of a single cone and a lug matched by a bearing. According to different strata and construction requirements, different cutting structures can be selected; wear resistant carbide are welded and cemented carbide inserts are inserted on the back of the lug.
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- Working principle
- Rotary drilling rig drives shaft to rotate and exert positive pressure so that the rotary drilling bit can impact, roll and shear the rock, crush the rock to form a crushing ring zone, and then break the middle pillar by the swing of the shaft, and take the broken pillar out to form a hole.
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- Bit naming
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Shareate single roller bit product model is divided into four sections: drill bit diameter code, drill bit series code, IADC code, and additional features code. Using 8 1/2 YHA617Y as an example:
3.1 Drill bit size
Displayed in numbers to indicate the diameter in inches.
3.2 Series code
Displayed by 3 English letters.
· The first letter represents the type of bit: Y represents single cone bit, T represents two cone bit, M represents tricone bit.
· The second letter represents the bearing of bit, H represents journal bearing, G represents roller bearing.
· The third letter represents the seal of bit, A represents O-type rubber seal, V represents flat rubber seal.
3.3 IADC code
It consists of three digits, the first digit represents the type of drill bit cuting structure and formation hardness, the second digit is the formation classification number, and the third digit is the bearing and sealing characteristics code.
· The first digit ranges from 4 to 8, which designates soft formation, medium-soft formation, medium-hard formation, hard formation and extremely hard formation.
· The second digit:1、2、3、4(classification of formation,Higher values indicate higher formation hardness).
· The third digit: Shareate usually uses 5(sealed roller bearing),7(sealed journal bearing).
Code Additional feature F Cone auxiliary carbide protection G Specific lug back strengthening W Shirttail hard facing X Wedge inserts Y Ovoid inserts
The Feature of Structure
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Shareate rotary drillbit mainly uses sealed journal bearing, which consists of bore of cone shaft,Journal of palm of tooth, steel ball and rubber sealing ring (see figure below). According to a lot of experience in using rotary dril bit, the bearing has stable structure, strong bearing capacity and low risk of losing the cone, and is suitable for various hardness and lithology formations. |
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● Application
50 ~ 130 MPa, Medium, breezed granite, limestone, dolomite, gravel etc. Medium and high compressive strength formation, strong homogeneity, medium and low abrasive formation.
● Feature
| IADC Code: | 6‑1‑7 |
| Bearing: | Journal bearing |
| Sealing: | O‑type rubber seal |
| Cutting structure: | Conical |
| Rows/Qty: | 7/52 |
| Shirttail/Lug | Welding carbide & adding inserts |
● Crashing rock width
114～118mm
● Recommend drilling pressure
Pull‑down on the Cylinder: 20‑30 T ( maximum pull‑down on every single cone bit: 5‑6 T )
● Operating suggestions
| Rock formation | Recommended Drilling Pressure | Recommend ROP | |
|---|---|---|---|
| Hole depth ( m ) | Rotation Speed ( RPM ) | ||
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Medium hard (50‑100Mpa) |
20‑30t | 0.8‑1.5 | 112‑16 |
| 1.5‑2 | 10‑12 | ||
| 2‑2.5 | 6‑10 | ||
| 2.5‑2.8 | 3‑6 | ||
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Hard (80‑150Mpa) |
20‑35t | 0.8‑1.5 | 10‑12 |
| 1.5‑2 | 8‑10 | ||
| 2‑2.5 | 5‑8 | ||
| 2.5‑2.8 | 2‑5 | ||
*Note: in the same parameter range, if the cylinder diameter is larger, then rotation speed will be lower. The rated pull‑down on single cone bit is 5‑7 T, rated speed is 60‑100rpm.
● Application
80 ~ 150MPa, Granite, basalt, quartz porphyry, gravel, etc.Medium and high compressive strength formation, strong formation homogeneity, mixed formation, high abrasive formation.
● Feature
| IADC Code: | 6‑3‑7 |
| Bearing type: | Journal bearing |
| Sealing: | O‑type rubber seal |
| Cutting structure: | Conical |
| Rows/Qty: | 6/42 |
| Shirttail/Lug | Welding carbide & adding inserts |
● Crashing rock width
114～120mm
● Recommend pull‑down
Pull‑down on the Cylinder: 20‑35 T ( maximum pull‑down on every single cone bit: 5‑6 T )
● Operating suggestions
| Rock Formation | Recommend Pull‑down | Recommend ROP | |
|---|---|---|---|
| Hole depth ( m ) | Rotation Speed ( RPM ) | ||
|
Medium hard (50‑100Mpa) |
20‑30t | 0.8‑1.5 | 12‑16 |
| 1.5‑2 | 10‑12 | ||
| 2‑2.5 | 6‑10 | ||
| 2.5‑2.8 | 3‑6 | ||
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Hard (80‑150Mpa) |
20‑35t | 0.8‑1.5 | 10‑12 |
| 1.5‑2 | 8‑10 | ||
| 2‑2.5 | 5‑8 | ||
| 2.5‑2.8 | 2‑5 | ||
*Note: in the same parameter range, if the cylinder diameter is larger, then rotation speed will be lower. The rated pull‑down on single cone bit is 5‑7 T, and rated speed is 60‑100rpm.