摘要 |
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.
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