| 摘要 |
PURPOSE: To suppress the decrease in a torque constant of a motor thereby to obtain a disc drive apparatus of high reliability, by reducing the leakage of dust generated inside the motor to the outside and making small an effective gap between the outer periphery of a stator core and the inner periphery of a driving magnet. CONSTITUTION: The disc drive apparatus is provided with an annular driving magnet 2 rotating together with a hub 1 and a stator core 7 facing opposite to the driving magnet 2. the hub 1 of the disc drive apparatus is rotated by the magnetic action of the driving magnet 2 and stator core 7. The driving magnet 2 is a resin-bonded magnet including rare earth-transition metal-boron based magnetic particles and a polyimide binder, with having a plurality of grooves 8 at a lower end face 10 thereof to control the flow of air in an inner peripheral direction. Morever, the driving magnet 2 is formed by injection molding, and at least molded surfaces of an inner peripheral face and the lower end face 10 are exposed. |
