Abstract: A rotating body, which rotates about an axis, includes a recessed reference mark and at least one recessed dummy mark. The reference mark is provided on the surface of the rotating body, serves as a reference for detecting the rotational phase of the rotating body, and can be detected with an electromagnetic wave. The dummy mark is provided on the surface of the rotating body, and is located at a position separated from the reference mark by an angle greater than 90 degrees about the axis.

Abstract: A rotating body, which rotates about an axis, includes a recessed reference mark and at least one recessed dummy mark. The reference mark is provided on the surface of the rotating body, serves as a reference for detecting the rotational phase of the rotating body, and can be detected with an electromagnetic wave. The dummy mark is provided on the surface of the rotating body, and is located at a position separated from the reference mark by an angle greater than 90 degrees about the axis.

Abstract: An imbalance correction method for correcting the imbalance of a rotor measures the vibration state of the rotor before temporary correction and the vibration state of the rotor after the temporary correction in a plurality of rotational speeds in order to make vibration values below the standard. An aggregation range of the tips of correction vectors for obtaining a vibration value which satisfies a vibration standard is calculated from vibration vectors in the rotational speeds. A real correction vector is selected from correction vectors having the tips in a region in which the aggregation ranges calculated for each of the rotational speeds overlap one another among a plurality of the correction vectors. A real correction amount and a real correction phase are set based on the real correction vector. The imbalance of the rotor is corrected based on the real correction amount and the real correction phase.

Abstract: An imbalance correction method for correcting the imbalance of a rotor measures the vibration state of the rotor before temporary correction and the vibration state of the rotor after the temporary correction in a plurality of rotational speeds in order to make vibration values below the standard. An aggregation range of the tips of correction vectors for obtaining a vibration value which satisfies a vibration standard is calculated from vibration vectors in the rotational speeds. A real correction vector is selected from correction vectors having the tips in a region in which the aggregation ranges calculated for each of the rotational speeds overlap one another among a plurality of the correction vectors. A real correction amount and a real correction phase are set based on the real correction vector. The imbalance of the rotor is corrected based on the real correction amount and the real correction phase.