Patent ID: 7918291

Claim:
A bearing assembly for a well drilling head comprising: an outer barrel having a central bore: an inner barrel at least partially disposed within the central bore of the outer barrel; a plurality of bearing units coupled between said barrels for providing concentric alignment of said barrels and allowing rotation therebetween, wherein said plurality of bearing units jointly carry loads exerted radially between said barrels and loads exerted longitudinally between said barrels; a preload force exerting member disposed between said barrels, wherein the inner barrel extends through an opening within the preload force exerting member, wherein the preload force exerting member maintains force on said barrels and on at least one said bearing units carry load exerted longitudinally between said barrels, and wherein the preload force exerting member is one of a force exerting washer and a spring; and a stripper rubber attachment structure integral with a lower end portion of the inner barrel.