Patent ID: 9605682
Date: 2017-03-28
CPC Classifications: F04D

Claim:
1. A blower fan comprising: a motor; an impeller caused by the motor to rotate about a central axis; and a housing arranged to contain the motor and the impeller; wherein the motor includes: the rotating portion includes a rotor holder including a first holder member and a second holder member including an outer circumferential surface to which the impeller is fixed; the first holder member includes: the second holder member includes a cover portion including, in an inner edge portion thereof, a cover cylindrical portion arranged to extend downward; the rotor cylindrical portion includes an annular rotor raised portion arranged to project radially outward from an outer circumferential surface thereof; the second holder member is attached to the first holder member; and a lower end portion of the cover cylindrical portion is arranged to be in axial contact with the rotor raised portion, the bearing apparatus includes: an inner circumferential surface of the bushing is fixed to a lower portion of an outer circumferential surface of the bearing housing through adhesion or press fit; an inner circumferential surface of the rotor cylindrical portion and an outer circumferential surface of the bearing portion are arranged to together define a seal gap therebetween, the seal gap including a seal portion having a surface of a lubricating oil defined therein; the bushing includes: an inner circumferential surface of the bushing cylindrical portion and the outer circumferential surface of the rotor cylindrical portion are arranged to together define a vertical gap extending in an axial direction therebetween; the vertical gap is arranged to have a minimum radial width equal to or smaller than a maximum width of the seal gap, the bushing cylindrical portion is arranged axially opposite the rotor raised portion; and a lower end portion of the rotor raised portion and an upper end portion of the bushing cylindrical portion are arranged to together define a horizontal gap therebetween.