Patent attributes
In an axial fan, a case (40) accommodating the fan motor stator (50) is anchored into a bearing retainer (10), in which ball bearings (20, 21) as a bearing unit are accommodated, along a bulge part (13) formed on the lower end portion thereof. The case (40) extends heading axially downward, wherein there is no diametrical overlap between the ball bearings (20, 21) and the stator (50). Since only the bulge part (13) of the bearing retainer (10) is fixed to the case (40), heat arising from the stator (50) is thermally conveyed via the case (40) only to the bulge part (13). The fact that the thermal conveyance zone is minimal enables unrestrained curtailment of heat transmitted to the ball bearings (20, 21). As a result the axial fan can be designed for prolonged bearing lifespan.
