13 3/4" FSA437G , TCI Bit , Sealed Journal Bearing with Gauge
Protection , Tricone Roller Bit , Tricone Drill Bit
RECOMMENDED DRILLING PARAMETERS FOR APPLICATION
| Types & IADC Code | 417 | 437 447 | 517 527 | 537 547 | 617 627 | 637 |
| WOB | KN/mm(Bit Dia.) | 0.4~0.9 | 0.4~0.9 | 0.35~1.0 | 0.5~1.0 | 0.6~1.1 | 0.7~1.2 |
| Lb/in. (Bit Dia.) | 2285~5142 | 2285~5142 | 2000~5714 | 2857~5714 | 3428~6285 | 4000~6857 |
| Rotation Speed (Rpm) | 140~60 | 140~60 | 125~50 | 110~50 | 100~40 | 80~40 |
The above chart represents commonly available sizes and types, we
do produce other sizes and types of rock bits which do not appear
on this list. Please contact us for more information.
Design of journal bearings
Journal bearings must provide a balanced bearing geometry and
adequate journal strength and must maximize the thickness of the
high-pressure lubricating film developed during hydrodynamic
lubrication. The thickness of lubricating films is affected by:
- Surface areas
- Journal and cone diameters
- Clearances between journal and cone
Manufacturing tolerances must be precise so that surfaces run true.
Roundness of journal and cone surfaces is important, and if any
part of a bearing is out of round, the effectiveness of the
lubrication regime will be adversely affected.
The metallurgy of a bearing must be balanced to minimize heat
generation during boundary lubrication. Cone-bearing surfaces are
steel. Soft, silver-plated sleeves are installed on the journal.
Silver polishes easily, and minor surface irregularities from
machining are quickly smoothed. This smoothness ensures
low-friction operation and uniform lubricant flow over the bearing
surface
