Patent ID: 6390209
Filing Date: 2002-05-21
Classification: E21B

Abstract:
A roller cone drill bit having a sealed lubrication system with a pressure compensator device said pressure compensator device comprising:a cavity within a drill bit, said cavity having a lower wall which communicates with the ambient environment and side walls which abut said lower wall; a hollow body member which fits within said cavity in the drill bit and is connected to a lubricant passageway; an annular seal member encircling said hollow body and located on one side of said lubricant passageway and arranged to sealingly engage said cavity; an elastomeric diaphragm member mounted on said hollow body member and having a lip encircling said hollow body and arranged to sealingly engage said cavity on the other side of the lubricant passageway; wherein the diaphragm member has a plurality of standoffs which engage the lower wall of the cavity, thereby maintaining fluid communication between portions of said cavity adjacent said side walls and the ambient environment.