Patent ID: 8215841

Claim:
A bearing assembly comprising: an outer housing having a first end, a second end and an interior surface that defines an interior cavity; an inner mandrel having an exterior surface, and a majority of the inner mandrel extending into the interior cavity of the outer housing; radial bearing sleeves positioned between the exterior surface of the inner mandrel and the interior surface of the outer housing at both of the first end and the second end of the outer housing, and the radial bearing sleeves facilitating relative axial rotation of the inner mandrel and the outer housing; a thrust bearing assembly positioned within the interior cavity intermediate the first end and the second end of the outer housing, and the thrust bearing assembly comprising: a fixed bearing carrier fixed to the exterior surface of the inner mandrel, the fixed bearing carrier having a first end and a second end, with at least one first hard face bearing positioned at the first end and at least one second hard face bearing positioned at the second end; a first floating bearing carrier supporting at least one third hard face bearing that engages, in face to face, relation the at least one first hard face bearing at the first end of the fixed bearing carrier to withstand off-bottom axial loads; a first pressure responsive filler disposed between the first floating bearing carrier and a first shoulder formed in the interior surface of the outer housing, that permits the first floating bearing carrier limited angular adjustment in relation to the fixed bearing carrier to maintain the at least one first hard face bearing and the at least one third hard face bearing in face to face relation notwithstanding deflections within required radial bearing tolerances; a second floating bearing carrier supporting at least one fourth hard face bearing that engages, in face to face relation, the at least one second hard face bearing at the second end of the fixed bearing carrier positioned at the second end of the fixed bearing carrier to withstand axial loads experienced when drilling; a second pressure responsive filler disposed between the second floating bearing carrier and a second shoulder formed in the interior surface of the outer housing that permits the second floating bearing carrier limited angular adjustment in relation to the fixed bearing carrier to maintain the at least one second hard face bearing and the at least one fourth hard face bearing in face to face relation notwithstanding deflections within required radial bearing tolerances; and a lubricating drilling fluid flow path extending between the radial bearing sleeves at the first end of the outer housing to the radial bearing sleeves at the second end of the outer housing, and the fluid flow path traversing the at least one first and third hard face bearings, the interior cavity and the at least one second and fourth hard face bearings.