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