| 摘要 |
PROBLEM TO BE SOLVED: To attain thinning of an electric fan without causing deterioration in the durability and vibrations or the like of a ball bearing. SOLUTION: A thin electric fan includes a commutatorless motor 2 comprising a stator 11 having a coil 12, and an outside turning type rotor having a cylindrical magnet 33, a fan blade 3 provided on the outer periphery of the rotor, and a casing 1 supporting the stator 11, wherein the fan blade 3 is formed with a thin metal plate of such as stainless steel, a rotating shaft 34 fixed at a center of the rotor is rotatably supported via a single ball bearing 35 provided at a side of the casing 1, and a magnetic plate 21 which confronts an end face of the cylindrical magnet 33 is arranged at a bottom portion of the casing 1. The magnetic plate 21 assumes an annular form and has a notch portion 38 at a part of a circumferential direction, then a hole device 18 for detecting a magnetic pole is disposed at the notch portion 38, and pressurization is applied to the ball bearing 35 by magnetic attraction force generated between the magnetic plate 21 and the cylindrical magnet 33. COPYRIGHT: (C)2005,JPO&NCIPI
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