To provide a motor fan in which the rotor will not move vertically downward, even if the motor fan is used, while being fixed facing down, and preventing shortening of its lifetime due to abnormal contact of the rotary shaft with the inner circumferential wall of a bearing hole.
The motor fan 1 comprises a base section 2, a bearing section 11, a stator 13 having a core 15 and a coil 16, a rotor 4 having a rotary shaft 20 and a cylindrical magnet 22, an air supply blade 5, and a rotor position detector 23 disposed on the base section 2 side of the cylindrical magnet 22, through a predetermined gap to the cylindrical magnet 22. The motor fan 1 is further provided with a thin part 24, where the effective thickness at one end part of the cylindrical magnet 22 on the rotor position detector 23 side is set thinner than the effective thickness at the other end part.
YAMASHITA AKITOMO
Tomoyasu Sakaguchi
Hiroki Naito