A rock drill bit includes at least one leg about which a roller cutter is rotatably mounted. A ring-shaped seal is disposed between an end surface of the leg and a sealing surface of the roller cutter. The seal is arranged coaxially with respect to an axis of rotation of the roller cutter and is formed of an elastic material and a relatively rigid material embedded within the elastic material. The elastic material defines first and second surfaces which engage the leg and the roller cutter, respectively. Either the leg or the seal includes circumferentially spaced recesses which receive respective projections formed in the other of the leg and the seal, for locking the seal to the leg against rotation relative thereto.
Disclosed is a seal assembly for dynamically sealing between rotatable members, such as employed to seal the rolling cone of a rock bit. One preferred assembly includes an energizer, first and second seal rings, and a cushioning ring having an L-shaped cross-section disposed about portions of one of the seal rings to seal and absorb impact loads and thereby protect the more-rigid seal rings.