A bracket of a rotation device of the present invention has a guide mechanism that is configured to guide a first motor and a second motor so as to rotate the same about an axis of a cylindrical rotating body relative to each other. A first gear and a second gear can respectively be meshed with rotating body side gears corresponding thereto while the first motor or the second motor is deviated around the axis of the cylindrical rotating body from a normal attachment position with respect to the bracket. Further, the first motor or the second motor can be guided to the normal attachment position by the guide mechanism in the condition.