CHUCKING DEVICE, MOTOR, AND DISK DRIVE

PROBLEM TO BE SOLVED: To provide a structure which can suppress vibrations and noise and can arrange a disk mounting part and a centering part on a surface being design reference with respective high position accuracy.SOLUTION: In a chucking device 104, a disk mounting part 141 for mounting a disk and a centering part 139 for supporting an inner circumferential part of a disk are different members. That is, the disk mounting part and the centering part do not continue but respectively fixed directly or indirectly to a shaft 131. Therefore, the disk mounting part and the centering part can respectively be arranged at a surface to be design reference with high position accuracy. Compared with when a unified member including a part corresponding to the disk mounting part and the centering part is fixed near to an upper end part of the shaft, a load applied close to the upper end part of the shaft is reduced. Thus, elastic deformation near the upper end part of the shaft is suppressed. As a result of this, vibrations and noise during rotation are suppressed.