Patent ID: 8328533

Claim:
A heat dissipation fan comprising: a base; a stator mounted on the base; and an impeller rotatably attached to the base, the impeller comprising a hub and a plurality of blades, the hub comprising a top wall and an annular wall depending from the top wall, the top wall facing downwardly toward the base, the annular wall surrounding the stator, the blades being arranged around the annular wall, a shaft extending perpendicularly from one of the base and the top wall, a bearing tube extending perpendicularly from the other one of the base and the top wall, the shaft being rotatably received in the bearing tube; wherein the stator defining an air passage therein along an axial direction of the impeller, each of the top wall and the base defining a plurality of holes, the holes of the top wall communicating with the holes of the base via the air passage, the bearing tube extending into the air passage and being spaced from the stator; wherein the air passage communicates with the holes of the top wall and the base, the shaft extends upwardly from a central portion of the base, the holes of the base are evenly arranged around the shaft, the bearing tube extends from a central portion of the top wall, the holes of the top wall are evenly arranged around the bearing tube; and wherein a holding plate is formed between every two adjacent holes of the top wall, each of the holding plates extending perpendicularly from the top wall towards a bottom of the hub and connecting with an outer surface of the bearing tube, each of the holding plates being spaced from the stator.