BEARING AND LUBRICATION SYSTEM FOR EARTH BORING BIT

摘要

Methods and apparatus for maintaining lubrication of rolling cone cutters mounted on journal pins. Embodiments comprise a rotating cone disposed on a journal pin and forming a journal gap there between. A cylindrical journal sleeve is disposed in the journal gap. The journal sleeve has a longitudinal gap forming opposing end portions, which a re continuously contoured. A lubrication port is disposed in the journal pin and in fluid communication with a lubrication supply. The lubrication port has an outlet located in a recess i n the journal gap. Each end of the recess comprises a transitioning surface extending between t he bottom of the recess and the outer surface of the journal pin to prevent sharp transitions . In certain embodiments, the journal pin may comprise two or more lubrication ports, eac h located in a recess with transitioning surfaces.