An inner tubular wall is concentrically located inside an outer tubular
wall to form an annular space therebetween. A bearing is retained within
the annular space. The bearing can include a pair of precision angular
contact bearings, the bearing may also include an axial sleeve bearing. A
frangible element such as an annular shear groove is associated with one
of the outer tubular wall and the inner tubular wall. Separation occurs
at the frangible element and the bearing supports the inner tubular wall
member and the outer tubular wall member for rotation relative to each
other upon the coupling assembly experiencing a shear event. In addition,
the angular contact bearings may reduce any bending moments that might
otherwise impact upon the frangible element during normal operation. The
frangible element may be treated, for example, by shot-peening or coating
to reduce deterioration of the frangible element during normal operation.