Patent ID: 8905161

Claim:
A drill pipe protector assembly, comprising: a protector sleeve adapted to be mounted to a drill pipe string through a fluid bearing so as to be co-axially rotatable with respect to the drill pipe string; and a retainer arrangement adapted to axially fix the protector sleeve with respect to the drill pipe string, wherein the fluid bearing comprises a pair of bearing components co-axially arranged to form a pair of bearing surfaces radially opposite to each other with a first bearing gap containing a lubrication fluid therebetween and further comprises a pair of sealing arrangements at an axial distance from each other for sealing the bearing gap provided therebetween, wherein each sealing arrangement comprises at least one labyrinth type sealing having an annular groove in a first one of the bearing components and at least one ring member sealingly sealed to a second one of the bearing components, wherein the at least one ring member radially extends with radial play into the annular groove associated thereto, wherein the protector sleeve comprises an annular recess having a bottom surface forming a first one of the pair of bearing surfaces of the first bearing gap and annular inner side surfaces on axially opposite sides of the bottom surface, wherein the retainer element comprises an annular protrusion body radially extending into the annular recess and having an outer circumferential surface forming a second one of the pair of bearing surfaces of the first bearing gap and annular outer side surfaces on axially opposite sides of the outer circumferential surface, wherein the inner and the outer side surfaces each have a frustoconical shape and form in pairs second frustoconical annular bearing gaps containing lubrication fluid, and wherein an angle between one of the annular inner side surfaces and one of the two axially opposite sides of the bottom surface is equal to an angle between the other one of the annular inner side surfaces and the other one of the two axially opposite sides of the bottom surface.