| 摘要 |
PURPOSE:To prevent a noise from being generated, by extending the periphery of a subplate in a mixed flow impeller to an outer direction so as to obtain a diameter larger than the maximum diameter of a blade and providing a subwall, curved in a direction almost in parallel with a rotary shaft, in the peripheral end of said subplate. CONSTITUTION:A blower, providing plural blades 24 to be implanted between a truncated cone-shaped main plate 21 and a subplate 22 having in its center a suction port 23, extends the periphery of the subplate 22 to an outer direction so as to obtain a diameter larger than the maximum diameter of the blade 24. And the subplate 22 provides in its peripheral end a subwall 32 curved in a direction almost parallel with a rotary shaft. Thus the blower, causing a flow of air to be a forced outflow in the direction of a delivery port 31 in a casing 27 by the subwall 32 simultaneously increasing fluid resistance in a clearance between the subplate 22 and an internal wall of the casing 27, can suppress a flow of air flowing at a high speed in a direction of the suction port 23. Consequently, generation of a noise is prevented.
|
