| 摘要 |
PROBLEM TO BE SOLVED: To reduce the noise of the blower by suppressing the interference between the backflow air and the intake air. SOLUTION: A bell mouth is extended up to the edge of the inside diameter D1 of a fan 71 to cover a part of a blade 72, while generating a clearanceδ1 between a shroud 77 and an inner wall 74b of a casing 74. The ventilation resistance in an air flow channel 78 can be thus made larger. As a result, even if the ventilation resistance in the air-conditioning casing increases, the backflow air can be prevented from increasing. This also suppresses the interference between the backflow air and the intake air, so the noise can be decreased consequently.
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