Seal insert ring for roller cone bits

摘要

An earth boring bit has a bit body with a depending bearing pin. An insert ring is mounted on the bearing pin. The insert ring has an inner diameter greater than an outer diameter of the bearing pin, defining a clearance between the insert ring and the bearing pin to allow the insert ring to float relative to an axis of the bearing pin. An inner seal is in sealing engagement with the bearing pin and the inner diameter of the insert ring. A cone is rotatably mounted on the bearing pin, the cone having a cavity containing an outer seal groove. An outer seal located in the outer seal groove is in dynamic sealing engagement with an outer diameter of the insert ring. An anti-rotation member engages a portion of the insert ring to prevent rotation of the insert ring.