| 摘要 |
PROBLEM TO BE SOLVED: To provide a centrifugal fan which inhibits reverse flow and reduces noise.SOLUTION: A centrifugal fan 1 has an impeller 10 housed between an upper casing 21 and a lower casing 22. A cylindrical part 29 formed at an opening periphery of a front case 28 is disposed at the inner side of an opening of an annular shroud 11 of the impeller 10. An outer periphery of the cylindrical part 29 formed at the opening periphery of the front case 28 has an annular recessed part 30. The recessed part 30 forms a space between a front plate 31 and the front case 28. A cylindrical part 14 formed at an upper end part of the annular shroud 11 is disposed between an opening of the front plate 31 and the cylindrical part 29 of the front case 28. A gap L1 and a gap L2 are respectively formed in a space between the cylindrical part 14 of the annular shroud 11 and an opening periphery of the front plate 31 and a space between the cylindrical part 29 of the front case 28 and the cylindrical part 14 of the annular shroud 11.SELECTED DRAWING: Figure 1 |
