| 摘要 |
PROBLEM TO BE SOLVED: To provide a centrifugal blower capable of inhibiting generation of noise including periodic noise due to interference of a tongue part and an impeller. SOLUTION: This blower is provided with: the impeller 2 provided with a plurality of blades around a rotary shaft; a casing 3 storing the impeller 2 and having a suction part at one end side in an axial direction of the rotary shaft; a scroll channel 4 arranged around the impeller 2 in the casing 3; and the tongue part 6 inhibiting air from flowing into a start of winding from an end of winding of the scroll channel 4. An extension part 20 keeping a gap with the impeller 2 roughly constant in a radial direction of the impeller 2 and changing projection quantity to a reverse rotation direction according to a position in an axial direction is provided on a tip at a side of rotation reverse to rotation direction of the impeller 2 at the tongue part 6. COPYRIGHT: (C)2009,JPO&INPIT |
