Composite earth boring bit seal

摘要

A high performance rock bit journal seal is formed from a composite material comprising an elastomeric material and a nonelastomeric polymeric material. The polymeric material is preferably in the form of fibers compiled or woven into a sheet. The elastomeric material may include one or more lubricant additives. The composite seal material comprises a number of repeating sheets of polymeric fabric that are bonded together with the elastomeric material. The seal can either be formed entirely of the composite seal material or partially of the composite material, in which case it is preferred that the seal wear or dynamic surface be formed from the composite material and the remaining portion of the seal be formed from an elastomeric material. The seal can be used as a primary journal seal, or as a secondary journal seal in a dual seal bit. Seals formed from the composite seal material display enhanced wear resistance, reduced coefficient of friction, and improved high-temperature stability and endurance when compared to noncomposite seal materials, thereby both extending the useful life of seals formed therefrom formed and of rock bits that employ such seals.