| 摘要 |
PURPOSE:To prevent interference sound from generating, by forming, in the free end section of a blade, a curved section which has its width increasing from the leading edge to the trailing edge of the blade and which is inclined toward the lateral surface of the blade. CONSTITUTION:A blade 10 is fitted to a fan blade boss section 3 with a predetermined setting angle, and extends radially from the boss section 3. The blade 10 is formed at its free end with a curved section 12 which has its width increasing from the leading edges to the trailing edges of the blade 10 and which is inclined toward the lateral section 11 of the blade 10. The inclined angle alpha of the curved section 12 is selected in a range of 10 to 60 deg. and the maximum width of the curved section 12 is one-third or below of the outer diameter of the blade at the trailing edge 13 of the blade 10. With this arrangement air passing through the free end side of the blade 10 flows along the axial direction of the boss section 3, and therefore, will not impinge on the ring section of the shroud and the root section of a stay part. |
