This adapter sleeve provides a mounting interface between a shaft and a bearing bore, transmitting load through a tapered fit rather than a keyway connection. Bore diameter is 85.0 mm, net mass 1.437 kg, standard design, delivered as a complete mechanical unit with a locknut arrangement (FP execution) for fastening on the shaft. The tapered sleeve allows the bearing to be mounted on a plain cylindrical shaft, with clamping achieved by tightening the nut to draw the sleeve into the bearing bore, producing the required interference fit and internal clearance reduction. This design simplifies mounting and dismounting on long shafts and allows axial positioning at any point along the shaft length, without requiring a shaft shoulder or keyway.