Stopper, motor, and disk drive apparatus

A motor comprising:

• a stator;
• and
• a rotor which is arranged to rotate relative to the stator about a center axis as a center;
• wherein
• the rotor includes:
• a disk portion;
• a cylindrical portion which extends downward in an axial direction from the disk portion;
• and
• a stopper that is cylindrical or substantially cylindrical, is disposed on an inner side in a radial direction of the cylindrical portion and is fixed to an inner surface of the cylindrical portion;
• the cylindrical portion includes a cylindrical portion protruding portion which protrudes inward in the radial direction and opposes an outer surface of the stopper in the radial direction;
• the stopper includes a stopper protruding portion which protrudes outward in the radial direction, opposes the inner surface of the cylindrical portion, and opposes the cylindrical portion protruding portion in the axial direction;
• an adhesive is included between the cylindrical portion and the stopper;
• a gap in the radial direction between an upper end portion of the outer surface of the stopper and an inner peripheral surface of the cylindrical portion protruding portion defines a first tapered gap in which a gap in the radial direction widens upward in the axial direction;
• a gap in the radial direction between a lower end portion of the outer surface of the stopper protruding portion and an inner peripheral surface of the cylindrical portion defines a second tapered gap in which a gap in the radial direction widens downward in the axial direction;
• the adhesive is included in at least a portion of the first tapered gap and in at least a portion of the second tapered gap;
• the stator includes an annular surface that widens in the radial direction;
• and
• the annular surface is positioned below the second tapered gap and the second tapered gap opposes the annular surface in the axial direction.