Patent attributes
A rotating flow head has a lubricated bearing pack for isolating bearing elements from wellbore fluids under pressure. The bearing pack, having a rotating cylindrical sleeve, bearing elements and two seal assemblies, is secured within an assembly bore of a stationary housing by a retainer plate accepting a plurality of lag bolts circumferentially spaced around a top portion of the stationary housing. Each of the seal assemblies have at least one sealing element having a body, an annular cavity, an inner sealing surface, and a flange that distends radially outwardly when axially compressed. A loading ring fit to the annular cavity urges the inner sealing surface radially inwardly to sealingly engage the rotating cylindrical sleeve. The inner sealing surface further comprises a first and second sealing surface and a debris channel therebetween.