Patent ID: 8505652

Claim:
A bearing assembly for a rotating control device used in drilling wells, comprising: an outer barrel having a central bore extending between an upper end portion and lower end portions thereof, wherein an exterior surface of the outer barrel is configured for being engaged with a mating interior surface of a housing of the rotating control device within a central bore thereof and for being engaged by a bearing assembly retaining apparatus of the rotating control device to retain the outer barrel in fixed relationship with respect to the housing of the rotating control device, wherein the outer barrel includes a bearing assembly retention groove within the exterior surface thereof and wherein the bearing assembly retention groove extends partially around a circumference of the outer barrel such that the groove terminates at a key portion extended across the bearing assembly retention groove; an inner barrel at least partially disposed within the central bore of the outer barrel; bearing units coupled between said barrels for providing concentric alignment of said barrels and allowing rotation therebetween; a first bearing lubricant channel extending from said upper end portion of the outer barrel to said lower end portion of the outer barrel within a wall defining the exterior surface of the outer barrel, wherein the first bearing lubricant channel extends through the key portion; and a second bearing lubricant channel defined between the outer barrel and the inner barrel, wherein the second bearing lubricant channel extends from said upper end portion of the outer barrel to said lower end portion of the outer barrel, wherein said bearing units are exposed within the second bearing lubricant channel, and wherein the second bearing lubricant channel intersects the first bearing lubricant channel only at a location between a lowermost one of said bearing units and a lower end face of the outer barrel.