Waterproof structure for fan motor

Abstract

A waterproof structure for a fan motor comprising a vertical motor shaft projecting from the lower surface of a motor yoke and a fan boss portion which has a bottomed cylindrical shape formed by a bottom opposite to the lower surface of the motor yoke, an outer cylinder opposite to the outer periphery of the motor yoke and which is mounted on the motor shaft at the center thereof. The bottom of the fan boss portion, opposite to the lower surface of the motor yoke is partitioned by concentric circular ribs to form a plurality of enclosed rooms having floors which are successively lower in the direction toward the outer periphery and notches for allowing the adjacent enclosed rooms to communicate with each other are formed in the ribs in such a manner that the notches of the adjacent ribs are offset from one another so as to be placed on different radial lines. The structure produces a maze-like water guide passage for guiding water, which may enter the fan boss portion, from the inner to the outer enclosed rooms where drainage holes are formed in the floors of the enclosed rooms in the outermost periphery for the purpose of discharging the water guided thereto to outside of the fan boss portion. The waterproof structure thus provides excellent waterproofing capability that results in increased reliability of the fan motor.