Abstract: A storage disk drive motor 12 includes a stator unit 2, a rotor unit 3, a shaft 41 arranged in a coaxial relationship with a center axis 9, a sleeve unit 22 including a flange portion 223, and a base member 21, having a through-hole, fixed to the sleeve unit 22 by caulking. The flange portion 223 includes a flange lower surface 223b making contact with an upper surface 21a of the base member 21 and a jut 24 protruding downwards from a radial inner side of the flange lower surface 223b. The jut 24 includes a first outer circumferential surface 241 opposed to the inner circumferential surface 21c of the base member 21, a second outer circumferential surface 242 positioned below the first outer circumferential surface 241, and a groove 243 radially inwardly indented from the first outer circumferential surface 241 and the second outer circumferential surface 242.

Abstract: In a motor including a chucking device for detachably holding a disk, the chucking device has a center case to which a central opening of the disk is inserted; resilient members received within the center case; and claw members for holding the disk in place. Each of the claw members has a tip end portion, a disk holding surface positioned axially below the tip end portion for holding the disk in place, and a recessed sliding portion formed substantially at a circumferential center region of the disk holding surface, the sliding portion serving to guide movement of the claw member. Rest portions are formed in the center case to face the respective sliding portions, the rest portions serving to support the respective sliding portions by contacting therewith. The sliding portions are designed to make contact with the respective rest portions when the disk is mounted to the chucking device.

Abstract: In a motor including a chucking device for detachably holding a disk, the chucking device has a center case to which a central opening of the disk is inserted; resilient members received within the center case; and claw members for holding the disk in place. Each of the claw members has a claw portion having a disk holding surface for holding the disk in place and a pair of wing portions extending radially inwardly from the claw portion. Further, each of the wing portions has a spherical contact surface contacting with a underlying part arranged axially below the wing portions.

Abstract: In a motor including a chucking device for detachably holding a disk, the chucking device has a center case to which a central opening of the disk is inserted. The center case has a cylindrical portion coaxial with the center axis, a cover portion for covering an axial upper side of the cylindrical portion of the center case and a base portion fixed to the shaft-fixed portion of the rotor holder; resilient members received within the center case; and claw members remaining in contact with the respective resilient members, the claw members being movable radially to hold the disk in place. The center case is spaced apart from the rotor holder except for the base portion contacting with the shaft-fixed portion of the rotor holder.

Abstract: In a motor including a chucking device for detachably holding a disk, the chucking device has a center case to which a central opening of the disk is inserted; resilient members received within the center case; and claw members for holding the disk in place. Each of the claw members has a tip end portion, a disk holding surface positioned axially below the tip end portion for holding the disk in place, and a recessed sliding portion formed substantially at a circumferential center region of the disk holding surface, the sliding portion serving to guide movement of the claw member. Rest portions are formed in the center case in a facing relationship with the respective sliding portions, the rest portions serving to support the respective sliding portions by contacting therewith. Each of the rest portions has an upwardly convex curved surface with which the corresponding sliding portion makes contact.