| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that in a conventional axial fan, as air separates from a pressure surface to flow downstream and not along blades at the inner peripheral part of the fan, energy is hardly transmitted from the blades, and when the air does not flow along blade surfaces, blown-out flow is easily directed in the revolving direction of the fan, so that air flow is disturbed by a crosspiece and a rib of a protective grille installed at downstream of the fan and noise becomes large. SOLUTION: The axial fan 101 includes a plurality of blades on the circumferential face of a hub 1 mounted on a rotary shaft, and blows air in the axial direction through the rotation of the rotary shaft. In the axial fan 101, the main blade 5 and an auxiliary blade 6 are disposed at positions shifted from each other in the axial direction. The auxiliary blade 6 is disposed further on the axial downstream side than the main blade 5 and covers the rear edge 52 of the main blade 5. The fan diameter of the auxiliary blade 6 is smaller than that of the main blade 5. In the axial fan 101, the air flow on the inner peripheral side is made to flow along the main blade 5, activating energy transmission, and noise occurring in a fan grille can be reduced by directing the blown-out air flow in the axial direction. COPYRIGHT: (C)2010,JPO&INPIT
|
