This adapter sleeve provides a mounting interface between a shaft and a bearing with a tapered bore, allowing the bearing to be fitted onto a cylindrical shaft section. It has a bore diameter of 100.0 mm and a net mass of 1.99 kg, of standard design, complete and mechanical. The tapered outer surface of the sleeve is drawn under the bearing inner ring to create an interference fit through axial displacement, secured by a locknut. This construction compensates for the diameter difference between the shaft and the tapered bore of the bearing, allowing installation without requiring a precisely ground shaft seat, and permits axial positioning of the bearing along the shaft during mounting.