| 摘要 |
PURPOSE:To promote the smallness of size in a casing, by setting the height in a suction port side in a tongue part and a rear guider, which constitute a casing, to a value specified times the outside diameter of an impeller from an approaching point to the impeller. CONSTITUTION:A rear guider 4a sets its suction port side height h2 to a value about 0.4 times the outside diameter of an impeller from an approaching point (a) to the impeller 1. A tongue part 3a forms its suction port side height h1 to a value about 0.3 times the outside diameter of the impeller from an approaching point (c) to the impeller 1. The rear guider 4a sets its blowoff side length and blow port height to a value about 0.6-0.8 times the outside diameter of the impeller. Accordingly, a fan enables its performance to be prevented from deteriorating due to the miniaturization of a casing by moving the position of a vortex, generated in the internal periphery of the impeller, to the suction port side.
|
