| 摘要 |
PROBLEM TO BE SOLVED: To reduce an air amount which is re-sucked from a gap between a bell mouth and a shroud.SOLUTION: A centrifugal blower includes: an impeller including a shroud having an air suction port which opens in a circular manner around a rotary shaft of a fan motor, and a plurality of blades arrayed along a circumferential direction of the air suction port; and a bell mouth arranged by one end part being fitted in a peripheral edge part from the air suction port side in a state where a predetermined gap is provided between itself and an inner peripheral surface of the peripheral edge part of the air suction port of the shroud. At least one is provided out of: a plurality of first grooves which are provided at intervals in the circumferential direction on an inner peripheral surface of the peripheral edge part of the shroud, and which incline in the rotational direction of the impeller as heading in the direction opposite from the air suction port in the axial direction of the rotary shaft from an end of a suction side of the peripheral edge part; and a plurality of second grooves which are provided at intervals in the circumferential direction on an outer peripheral surface of one end part of the bell mouth, and which incline in the reverse direction from the rotational direction of the impeller as heading in the opposite direction from the one end part in the axial direction of the rotary shaft from an end of the one end part. |
