| 摘要 |
<p>ROTARY ROCK BIT WITH IMPROVED THRUST FLANGE A rolling cone cutter earth boring bit is provided having a pair of radial facing thrust bearing surfaces bounding the pilot pin of the journal and the pilot pin cavity on the cone. The thrust bearing surface of the cone defines a plurality of slots open to, and angled forwardly from, the pin cavity, and terminating within the annular bearing area. The bearing surfaces are, upon assembly, lubricated with a "smear grease" which, under drilling operation works its way to the radially outermost area of the bearing surfaces leaving the bearing area adjacent the pilot pin generally depleted of lubricant. The slots, being closed on the outer end and having radially inwardly impelling force, scrape the outwardly migrated lubricant from the journal pin thrust surface and direct it back toward the pilot pin area for redeposition to replenish lubricant in the radially inner area of the bearing.</p> |
