| 摘要 |
PURPOSE:To maintain the normal flow of wind and reduce noise by forming a plurality of through-holes which penetrate the inside of a hub at almost equal intervals on the whole periphery of the cylindrical surface of the hub and forming the air passage which communicates with the front and the rear surface sides of a vane wheel and allowing the partition wall between through holes to be used as partition vanes. CONSTITUTION:When a vane wheel 1 is revolved by a motor 9, air flows as shown by the arrow F in the drawing towards the front surface side A from the rear surface side B of the vane wheel 1, and the air in the vicinity of a hub 2 is inhaled into the hub 2 from the through holes 3 as shown by the arrow G, by the centrifugal fan formed as partition vanes 7, from the partition walls in a plural number of through holes 3 which are formed at almost equal intervals on the whole periphery so as to pentrate the cylindrical surface of the hub 2 from its outside to the inside. When the static pressure increases, air tends to flow F outward radially, and the flow to the outside and the flow in G direction are balanced, and the flow in the perpendicular direction to an axis is not formed, and the normal flow in the direction of arrow F is maintained. As a result, the smooth characteristic of noise level is obtained, so as to achieve a quiet ventilation. |
