Dual metal face seal with single recessed energizer

Abstract

An improved rigid face seal that minimizes pressure fluctuations in the lubricant in the vicinity of the seal assembly. The assembly has a first ring with a radial seal face that opposes and engages an opposed radial seal face of a second rigid ring. A first resilient energizer ring is compressed between opposed, generally conical surfaces, one on the first rigid seal ring and the other in a shaft seal groove. The mid-section of the first energizer ring is positioned relative to the journal bearing surface such that its inner periphery is inside the journal bearing surface and thereby defines an essentially constant, lubricant-filled volume between the seal assembly and the shaft seal groove--even as the cutter and seal assembly move relative to the shaft during drilling. A second energizer ring is provided to maintain sealing engagement between the radial seal faces of the first rigid ring and the second rigid ring. The energizer ring is compressed between the second rigid ring and a groove provided in the cutter. The second energizer ring thus positions the second rigid ring relative to the first rigid ring to maintain the sealing engagement of the radial seal faces of each respective rigid ring, and permits movement of the engaged rigid rings relative to the cutter and journal bearing shaft.