| 摘要 |
PURPOSE:To increase the amount of blown air and reduce noises by forming recessions, deeper as getting toward the suction side and the rotation-direction- side central axis, on the peripheral faces of bosses between adjacent blades. CONSTITUTION:Recessions 17 are made on the peripheral faces of bosses 9 between adjacent blades 8. The recessions 17 are made gradually deeper in the direction of rotation (shown by arrows) and as getting toward the suction side. That is, the recessions 17 have smooth curved surfaces made gradually deeper as getting toward the rotation direction side and suction side. Therefore, the suction-side area of the blades 8 is enlarged by the recessions 17 and sucked air is passed and guided to the discharge side smoothly along the peripheral faces of the bosses 9. Thereby the amount of blown air increases and noises are reduced. |
