Patent ID: 8554114

Claim:
A rotating-body restraining device comprising: a first gear provided on a rotational shaft of a rotating body and rotated together with the rotating body, the number of teeth included in the first gear being Za; a second gear that meshes with the first gear, the number of teeth included in the second gear being Zb, which is not equal to the product of Za and an integer n; a third gear provided on a rotational shaft of the second gear and rotated together with the second gear, the number of teeth included in the third gear being Zc, which is an integral multiple of a value obtained by dividing the least common multiple of Za and Zb by Za; and a restraining member that is movable toward the third gear and that restrains the third gear from rotating by moving to a position where the restraining member meshes with the third gear, wherein the third gear has a plurality of teeth formed at a constant pitch interval around a periphery thereof.