Pulley and structure having the same connected with driven unit

A structure comprising a driven unit and a pulley, wherein the pulley includes:

• a wheel portion including two circular end surfaces opposing each other and a side surface connecting the two end surfaces, wherein the side surface includes a main arc face and a branch arc face, the branch arc face has a head end connected to the main arc face and a tail end configured to connect a strap, the branch arc face has a width in an axial direction of the wheel portion smaller than a width of the main arc face, and the branch arc face and the main arc face form a continuous circular arc surface on which the strap rides;
• and
• a lug portion fixed to the wheel portion, wherein the lug portion is disposed at a position adjacent to the branch arc face along the width of the main arc face and extends to protrude beyond the branch arc face in a radial direction of the wheel portion, and the lug portion connects the pulley to the driven unit.