Patent ID: 8755145

Claim:
A base unit for use in a disk drive apparatus, comprising: a stator including a plurality of coils; and a base member; wherein the base member includes a hole portion through which a center axis passes, a first recess portion arranged on an upper surface of the base member to surround the hole portion and to accommodate at least a portion of the stator and depressed toward a lower surface of the base member, a second recess portion arranged radially outward of the first recess portion on the upper surface of the base member and depressed toward the lower surface of the base member, and at least one through-hole arranged in the first recess portion to extend through the upper surface of the base member and the lower surface of the base member; the second recess portion including a protrusion portion arranged on an upper inner surface of the second recess portion to protrude from the lower surface of the base member toward the upper surface of the base member and a third recess portion depressed from the lower surface of the base member toward the upper surface of the base member in a lower-surface-side peripheral edge portion of the second recess portion and positioned at an opposite side from the protrusion portion.