| 摘要 |
PROBLEM TO BE SOLVED: To prevent lubricating oil of a built-in oil-impregnated bearing from leaking to the outside due to the temperature rise of a fan itself by driving, thereby suppressing the consumption of the lubricating oil and prolonging the lifespan of the fan. SOLUTION: The fan includes a casing integrally formed with a bearing housing, a motor equipped with a stator and a rotor and an impeller integrally formed with the rotor. The bearing structure of the fan according to the invention includes a cylindrical projection at the rim of a small hole in the bottom inner surface of the bearing housing, a cylindrical projection on the outer surface and a sealing member between the bottom inner surface and a top end surface of the oil-impregnated bearing. A labyrinth structure is formed by an annular recess portion at a top end surface of a boss of a rotor hub and the cylindrical projection on the bearing housing bottom outer surface. Otherwise, the sealing member includes a tubular portion integrally formed with a flange portion. The tubular portion is fitted and secured in a clearance between a rotor-shaft insertion hole and an outer peripheral surface of the rotor shaft. Further, the sealing member is so constituted as to include a cylindrical projection on its face opposite to the top end surface of the oil-impregnated bearing. COPYRIGHT: (C)2004,JPO
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