Abstract: A device and method for dynamically sealing between rotatable members such as a rolling cone of a rock bit. The assembly includes a seal ring having a facing surface of a relatively hard material, such as hardened steel or tungsten carbide, and a second seal ring of a softer material, the softer material being harder, however, than typical elastomers. Suitable materials for the relatively soft seal ring include tin, copper, aluminum, magnesium, lead and alloys thereof, as well as non-metallic materials such as nylon-zytel, acetal, and polypropylene. The relatively soft seal ring may be affixed to a third seal ring or maybe affixed directly to the cone steel, for example. The seal assembly provides potential for longer life relative to elastomeric seals and requires less axial space along the journal surfaces than certain conventional metal seal assemblies.

Abstract: Disclosed is a seal assembly for dynamically sealing between rotatable members such as a rolling cone of a rock bit. The assembly includes a seal ring having a facing surface of a relatively hard material, such as hardened steel or tungsten carbide, and a second seal ring of a softer material, the softer material being harder, however, than typical elastomers. Suitable materials for the relatively soft seal ring include tin, copper, aluminum, magnesium, lead and alloys thereof, as well as non-metallic materials such as nylon-zytel, acetal, and polypropylene. The relatively soft seal ring may be affixed to a third seal ring or maybe affixed directly to the cone steel, for example. The seal assembly provides potential for longer life relative to elastomeric seals and requires less axial space along the journal surfaces than certain conventional metal seal assemblies.