Patent ID: 6213228
Filing Date: 2001-04-10
Classification: E21B

Abstract:
A roller cone drill bit comprising:a plurality of arms having respective cones rotatably mounted on said arms;bearings located between ones of said plurality of arms and said respective cones;respective sealed lubrication systems providing lubrication to said bearings, said lubrications systems having a pressure compensator device, the compensator device consisting of:a hollow body member releasably connected to the drill bit body and sized to fit within the bit lubrication system with a lubricant passageway extending therethrough;an annular seal member encircling the hollow body and located on one side of the lubricant passageway and arranged to sealingly engage the drill bit; andan elastomeric diaphragm member mounted on the hollow body member and having a lip encircling the hollow body and arranged to sealingly engage the bit on the other side of the lubricant passageway;wherein the hollow body, seal, and diaphragm member are assembled into a unitary cartridge for introduction into a cavity in the drill bit as a single unit.