| 摘要 |
PROBLEM TO BE SOLVED: To provide a vortex flow fan capable of effectively suppressing pressure fluctuation on a tongue portion, in particular, between upper and lower surfaces of blades and the tongue portion, and significantly reducing nZ sound and harmonic wave.SOLUTION: A vortex flow fan includes an impeller having blades on an outer periphery of a hub, a motor for rotating the impeller, and a casing composed of a cylindrical portion covering the hub, an annular air chamber covering outer peripheral faces and upper and lower surfaces of the blades joined to an inner wall of the cylindrical portion, a suction port joined to the air chamber, a discharge port joined to the air chamber at a position circumferentially separated from the suction port, and a tongue portion separating the suction port and the discharge port. The tongue portion has the maximum clearance between the tongue portion and the blades at a corner of the tongue portion where a side face at a discharge port side, of the tongue portion and the inner wall of the cylindrical portion intersect, and the clearance is formed into the fan-shaped slant at the corner as the center, so that it is narrowed toward the tip of the fan shape, and becomes uniform at a suction port side from the tip. |
