Centrifugal fan with waterproof structure

摘要

A centrifugal fan capable of exhibiting enhanced waterproof performance without using a resin mold while being simplified in structure. Air is sucked from one axial side of a revolving shaft of an electric motor and discharged in a radial direction of the revolving shaft. A second side wall of a casing and a wall of a blade support of an impeller have opposite surface portions arranged opposite to each other in an axial direction of the revolving shaft, respectively. The opposite surface portions are formed into a configuration which permits the opposite surface portions to cooperate with each other to provide a labyrinth structure for preventing water from intruding into a space defined between a cup-like member and the second wall from an outside in the radial direction of the revolving shaft. A first side wall and the second side wall are formed with drainage through-holes.