|
|
- Main structure features
1. Sealed roller bearing structure. With rollers arranged in
grooves recessed in the cone body, the size of the bearing journal
is increased.
2. Thrust bearing surfaces are
hardfaced and treated with friction reducing technology.
3. All rubber compensator is
used which can limit pressure differential and prevent drilling
fluid from entering the lubrication system and this provides
the bearing system with good assurance of lubrication.
4. Ball locked cone, suitable
for high rotary speed.
5. New type of wear resistant
grease that can sustain high temperature up to 250¡ãC is utilized.
|
|
Bit
type
|
Formation |
Sealed
roller bearing |
Non-sealed
roller bearing
|
pressure(KN/mm)
(diameter of the bit ) |
Bit
sizes |
Series
|
Lithology |
| Steel tooth |
1 |
Soft with low compressive strength
and high drillability
|
S1M |
Y1P1 |
0.35-0.85 |
4-1/2¡å,4-5/8¡å,5-1/8¡å,
5-5/8¡å,6¡å,6-1/2¡å,
6-3/4¡å,7-1/2¡å,7-5/8¡å,
8-1/2¡å,9-1/2¡å,10-1/2¡å,
12-1/4¡å,13-5/8¡å,14-3/4¡å,
15-1/2¡å,17-1/2¡å |
| 2 |
Medium to medium hard with
high compressive strength
|
S2M |
Y3P3 |
0.5-1.2 |
| 3 |
Semi- abrasive & abrasive
hard formation
|
S3M |
Y5P5 |
0.9-1.2 |
| Insert bit |
4 |
Soft with low compressive strength
and high drillability
|
XHP2 |
S11 |
0.4-0.7 |
4-1/2¡å,4-5/8¡å,5-1/8¡å,
5-5/8¡å,6¡å,6-1/2¡å,
6-3/4¡å,7-1/2¡å,7-5/8¡å,
8-1/2¡å,9-1/2¡å,10-1/2¡å,
12-1/4¡å,13-5/8¡å,14-3/4¡å,
15-1/2¡å,17-1/2¡å
|
| 5 |
Soft to medium with low compressive
strength
|
XHP3 |
S22 |
0.5-0.9 |
| 6 |
Medium hard with high compressive
strength
|
XHP4 |
S33 |
0.7-1.0 |
| 7 |
Semi- abrasive & abrasive
hard formation |
XHP5 |
S44 |
0.7-1.05 |
| 8 |
Extremely hard with high abrasiveness
|
XHP6 |
S55 |
0.7-1.15 |
|
|
