| 摘要 |
<p>An earth boring rotary drill bit suitable for use in drilling oil wells and the like is disclosed. The rotary drill bit includes a rotating cone mounted on a journal that is protected by a primary seal and a secondary seal. The seals provide independent sealing action while coacting to stabilize the rotary motion of the cone. The primary seal defines a moving sealing surface in contact with the journal, and the secondary seal defines a moving sealing surface in contact with the rotating cone. The journal can have a frusto-conical or cylindrical configuration.</p> |
