ROTARY BODY ATTACHABLE TO A CRANKSHAFT

A rotary body (30) according to the present invention is made of resin and attached to a crankshaft (20). The rotary body (30) has an outside plate element (32) and an inside plate element (36) which are attached to an outside surface (24a) and an inside surface (24b) of an arm portion (24) of the crankshaft, respectively, and a pair of filler elements (34) disposed between the outside plate element and the inside plate element and on both sides of the arm portion. The outside plate element and the pair of the filler elements are coupled to each other, and the pair of the filler elements and the inside plate element are coupled to each other.