| 摘要 |
PURPOSE:To increase the amount of wind without increasing noises and to enhance the cooling effect by specifying the ratio of the outer diameter of an outer for and the diameter of an air-intake window of a fan cover and also the ratio of the outer diameter of an outer fan and the inner diameter thereof within the range of predetermined values, respectively. CONSTITUTION:The ratio A/D of the diameter A of an air-intake window 3a of a fan cover 3 and the outer diameter D of an outer fan 2 is specified as from 0.9- 1.15, and the ratio d/D of the inner diameter of the outer fan and the outer diameter D of the outer fan is specified as from 0.45-0.55. In this constitution, since the outer diameter of the fan is not long, noises are not large, and the fan operates as an axial-flow fan wherein the change in the direction of the wind flow is few; the amount of wind can be increased and the cooling performance can be enhanced. |
