Inner-rotor brushless motor

An inner-rotor brushless motor comprising:

• a rotor portion including a shaft extending in a vertical direction along a central axis;
• a stator portion located radially outside of the rotor portion;
• and
• a bearing portion configured to support the rotor portion with respect to the stator portion;
• wherein
• the rotor portion includes:
• a rotor configured to rotate together with the shaft, and including at least one magnet;
• and
• an upper cylindrical portion and a lower cylindrical portion located axially above and below, respectively, the rotor, and configured to rotate together with the rotor;
• the stator portion includes:
• a stator located radially opposite to the rotor with a gap intervening therebetween;
• a housing configured to hold the stator;
• a cap located axially above the housing;
• and
• a circuit board held by one of the housing and the stator, and including a rotation detection portion located thereon;
• the bearing portion includes:
• an upper bearing configured to rotatably support the shaft and held by the cap axially above the stator;
• and
• a lower bearing configured to rotatably support the shaft and held by the housing axially below the stator;
• the lower cylindrical portion includes a lower balance correction portion;
• and
• the upper cylindrical portion includes a detectable portion configured to be detected by the rotation detection portion located thereon, and includes an upper balance correction portion.