Radial rock bit seal

摘要

An improved radial rock bit seal for utilization with earth boring drill bits which employ rolling cutters mounted on shafts extending from face surfaces on the drill bit body. The improved seal includes a cylindrical body which is disposed around each shaft and which has two axially displaced seal portions. The first seal portion includes an elastomeric sealing surface which is disposed in sealing and sliding engagement with the shaft. The second seal portion includes an elastomeric sealing surface which is disposed in sealing and sliding engagement with the rolling cutter. A flexible juncture between each of the two seal portions permits the seal portions to move somewhat independently in response to loading of the rolling cutter and this permits both seals to maintain substantially the same seal compression in spite of such loading. In a preferred embodiment of the present invention, a rigid ring is utilized in conjunction with the elastomeric sealing surface that contacts the rolling cutter and is sized to maintain a selected amount of compression on the elastomeric sealing surface that contacts the inner surfaces of the cutter and an additional ring is used in conjunction with the elastomeric sealing surface that contacts the shaft so as to center the seal around the shaft and to cause the elastomeric sealing surface to form a seal around the shaft.