Patent ID: 7849474

Claim:
A motor comprising: a chucking device for detachably holding a disk-shaped storage medium having a central opening; a rotating member including a rotor magnet rotatable about a specified center axis and a turntable having a mounting portion for mounting the storage medium; and a fixed member for supporting the rotating member, the fixed member having a stator disposed in a facing relationship with the rotor magnet, the stator adapted to produce a rotating magnetic field in cooperation with the rotor magnet, wherein the turntable has a cover portion for covering an axial upper side of the stator and the chucking device is arranged on an axial top surface of the cover portion, wherein the chucking device comprises: a plurality of radially outwardly biased claw members having radial outermost tip sections; a centering case having reception holes for allowing the claw members to move radially and rest portions provided in the respective reception holes, the rest portions making sliding contact with the respective claw members when the tip sections of the claw members are moved axially downwardly, the reception holes being disposed radially inwardly of the central opening of the storage medium when the storage medium is mounted on the mounting portion; and resilient members received within the centering case for radially outwardly biasing the respective claw members by making contact therewith, wherein the tip sections of the claw members move axially downwardly and radially inwardly when the central opening of the storage medium is fitted around the centering case and the claw members make contact with a top edge of the central opening of the storage medium when the storage medium is mounted on the mounting portion, wherein the claw members make contact with a top surface of the cover portion of the turntable when the claw members are in contact with the top edge of the central opening of the storage medium, wherein the claw members are provided with contact sections for making contact with the top surface of the cover portion of the turntable and the turntable is provided with a contact section for making contact with the claw members, and wherein at least one of the claw member's contact sections and the turntable's contact section has surface roughness greater than the surface roughness of the rest portions and the portions of the claw members making contact with the rest portions.