| 摘要 |
A spindle motor arranged to rotate a disk about a center axis extending in an up-down direction includes a rotary unit including a rotor magnet and a stationary unit including a stator opposed to the rotor magnet and a base plate. The base plate includes a flat plate-shaped member positioned around the center axis and made of a first kind of metallic material and a base body axially overlapping with the plate-shaped member and made of a second kind of metallic material. The first kind of metallic material is larger in Young's modulus than the second kind of metallic material. The base body includes a cylindrical or substantially cylindrical bearing attachment portion axially extending about the center axis and a bottom plate portion radially extending from a lower portion of the bearing attachment portion. The plate-shaped member is positioned below the bottom plate portion to contact the bottom plate portion. |
