Patent ID: 6247545
Filing Date: 2001-06-19
Classification: E21B,F16C,F16J

Abstract:
A rolling cutter drill bit comprising a bit body with a plurality of depending legs, a bearing shaft formed on one of the legs, and a rolling cutter rotatably mounted upon the bearing shaft, a bearing cavity formed in the rolling cutter, a floating journal bearing having an outside diameter and an inside diameter, the floating journal bearing mounted between the bearing shaft and the bearing cavity, a lubricant within the bearing cavity, an annular groove formed on the bearing shaft, and a single energizer rigid face seal mounted upon the bearing shaft to rotatably seal the lubricant within the rolling cutter, the single energizer rigid face seal sealingly engaging a sealing face in the rolling cutter,the single energizer rigid face seal comprising a rigid seal ring, a floating static seal, and a non-sealing elastic energizer, the floating static seal is mounted in the annular groove between the rigid seal ring and the bearing shaft,the floating static seal axially movable within the annular groove to a first operating position wherein the seal assembly is volume balanced for the outside diameter of the floating bearing,the floating static seal axially movable to a second operating position within the annular groove wherein the seal assembly is volume balanced for the inside diameter of the floating journal bearing,wherein the floating static seal is axially displaced during operation between the first and the second operating positions.