| 摘要 |
<p>1531364 Drill bits SKF INDUSTRIAL TRADING & DEVELOPMENT CO BV 16 Feb 1976 [17 Feb 1975] 05993/76 Heading E1F Each rotary cutter 9 of an earth boring bit has a central pin 13 carrying the inner races 18 of angular contact ball bearings whose outer races are defined by a member 11 which is in peripheral sealing relation with the interior of the cutter and which is releasably secured to a leg 8 of the bit by a clamp ring 24. A diaphragm 14 carried by the nut subjects the lubricant in the cutter to ambient hydrostatic pressure. Taper, conical or like rolling bearings a combination of rolling and plain bearings can be used in alternative constructions. In the Fig. 2, embodiment, a double-row taper bearing is provided in each cutter, and one of the inner races is threaded onto the pin 13 which is welded to the cutter after machining. The member 11 defining the outer races carries a pressure-equalizing diaphragm 14 and is secured to the bit by clamp screws.</p> |
