Balance member, motor, and disk drive apparatus

A motor comprising:

• a fixed portion;
• a rotating portion arranged to rotate relative to the fixed portion about a central axis;
• and
• a balance member locked to the rotating portion;
• wherein
• the balance member is substantially arc-shaped and has first and second end portions opposing each other in a circumferential direction, the balance member includes a first arc-shaped portion and a second arc-shaped portion, the second arc-shaped portion is positioned in a middle of the first arc-shaped portion in the circumferential direction, and a thickness of the first arc-shaped portion in at least one of an axial direction and a radial direction of the central axis is greater than a thickness of the second arc-shaped portion in the axial direction and the radial direction, respectively.

A disk drive apparatus comprising:

• a motor including a fixed portion, a rotating portion arranged to rotate relative to the fixed portion about a central axis, and a balance member installed on the rotating portion;
• a disk installed on the rotating portion;
• an access portion arranged to write and/or read information on and from the disk;
• and
• a housing accommodating therein the motor and the access portion;
• wherein
• the balance member is substantially arc-shaped and has first and second end portions opposing each other in a circumferential direction, the balance member includes a first arc-shaped portion and a second arc-shaped portion, the second arc-shaped portion is positioned in a middle of the first arc-shaped portion in the circumferential direction, and a thickness of the first arc-shaped portion in at least one of an axial direction and a radial direction of the central axis is greater than a thickness of the second arc-shaped portion in the axial direction and the radial direction, respectively.