Patent ID: 7259486

Claim:
An axial fan, comprising: a shaft; a magnetic drive unit made up of a cylindrical rotor magnet fixed along one end of, and rotational unitarily with, said shaft, and a stator having a plurality of magnetic-pole teeth whose radial end portions diametrically oppose the cylindrical surface of said rotor magnet; a pair of bearings disposed along the opposite end, with respect to said magnetic drive unit, of said shaft at an axial separation, said pair of bearings for rotatably supporting said shaft and being of outer diameter smaller than said magnetic drive unit; a case having an axially extending interior cavity in which said magnetic drive unit is accommodated and into which said stator is anchored; a bearing retainer for supporting said pair of bearings, and fixed to said case and being of outer diameter smaller than said case; a plate fixed to a portion of said case that is closer to one end of said case than said stator, and opposing another end of said shaft with an axial gap therebetween and having an axially extending through hole; a circuit board arranged adjacent to said plate to radially coincide with said shaft at least partly; and an impeller fixed along said opposite end of said shaft beyond said pair of bearings, and being diametrically larger than the outer diameter of said magnetic drive unit, said impeller for rotating together with said shaft to generate an axially directed flow of air; wherein at least a portion of the through hole in said plate is radially non-coincident with said circuit board.