| 摘要 |
A drill bit for drilling into underground formations is disclosed, the drill bit having one or more first conduits (18) for supplying gaseous drilling fluid to the cutting cone bearings (14), one or more second conduits (19) for supplying lubricant to the cutting cone bearings (14), which conduits (18, 19) combine the gaseous drilling fluid with the lubricant in order to supply a mixture of gaseous fluid and lubricant to the bearings (14). |
