ROTOR AND METHOD FOR PRODUCING SAME

A rotator includes a rotating portion and a device fixed to the rotating portion, and the device includes a substrate and a flat secondary battery connected to the substrate via a terminal. The secondary battery includes an exterior body and a positive electrode and a negative electrode disposed in the exterior body. The exterior body includes a positive electrode can and a negative electrode can. The flat secondary battery is disposed in such a manner that one of the positive electrode can and the negative electrode can having a larger expansion amount on a central axis of the exterior body than the other of the positive electrode can and the negative electrode can faces the substrate, when the flat secondary battery expands due to a high temperature in a charging state of the flat secondary battery.