Patent ID: 9028223
Filing Date: 2015-05-12
Classification: F04D,H02K

Abstract:
1. A ventilation fan comprising: a shaft arranged on a center of rotation of the ventilation fan; a rotor holding portion rotatably supported about the shaft via a bearing; a rotor magnet held on a radially outer surface of the rotor holding portion; a stator arranged opposite to the rotor magnet on the radially outer side of the rotor magnet; an impeller arranged to rotate together with the rotor magnet and the rotor holding portion; and a motor supporting portion arranged to support the stator and the shaft; wherein the motor supporting portion includes a base portion, a stator holding portion arranged to hold the stator, and a shaft holding portion arranged to hold the shaft; the base portion is made from a resin material, and the stator holding portion and the shaft holding portion are each provided by metal members; the stator holding portion and the shaft holding portion are embedded within the base portion; the shaft holding portion includes a cylindrical portion into which the shaft is inserted, and a shaft holding flange portion extending outwards in the radial direction from either one of an upper end or a lower end of the cylindrical portion; at least a portion of the shaft is directly held by the shaft holding portion such that the shaft does not rotate; the impeller includes a substantially cylindrical impeller cup supported by the rotor holding portion and a plurality of blades arranged on an outer circumference of the impeller cup; and the rotor holding portion is embedded within the impeller cup.