Patent ID: 8904845

Claim:
A method for manufacturing a damping shaft sleeve comprising: (a) forging a base material into a billet that includes a cylindrical body which has a first end and a second end opposite the first end, and an annular flange which extends from and surrounds the first end of the cylindrical body; (b) forging the cylindrical body to form a shaft hole that extends from the first end toward the second end in a lengthwise direction of the cylindrical body and that is blind; (c) inverting the base material and forming two annular grooves that are respectively indented from two opposite surfaces of the flange and that extend in the lengthwise direction of the cylindrical body; (d) forging the billet to form the flange into a bottom wall that is connected to the first end of the cylindrical body and that has a rugged surface facing the second end of the cylindrical body, and a side wall that extends from the bottom wall toward the second end of the cylindrical body in the lengthwise direction, the bottom wall cooperating with the side wall to form an asymmetrical and helical groove; and (e) forming the shaft hole to extend through the cylindrical body of the billet.