The taper sleeve is mainly divided into TB taper bushing, QD taper sleeve and STB taper bushing, the holes where the taper sleeve and the pulley match are all half-sided, and the two light holes on the taper sleeve and the two threaded holes on the pulley form a complete hole respectively, and a threaded hole on the taper sleeve forms a complete hole with a light hole on the pulley again. At the time of assembly, two screws are put on in the two threaded holes of the pulley, as the screw is continuously tightened in the threaded hole on the pulley, the thread action pushes the screw to the small end of the taper hole on the pulley, and the two light holes on the taper sleeve are not completely processed through, like this, when the head of the screw is against the bottom of the light hole, the force is transmitted to the taper sleeve, and the taper sleeve moves relative to the small end of the taper hole of the belt pulley relative to the pulley, and because of the taper at this time, the taper sleeve is constantly wrapped around the shaft, and the shaft reacts on the taper sleeve again, and then acts on the pulley. In this way, the pulley, taper sleeve and shaft are tightly assembled.