Axial support is done axial support it does the centrifugal fan and the device, and the under floor

摘要

PROBLEM TO BE SOLVED: To reduce the manufacturing cost of an underfloor ventilator in which generation of noises, reduction of supply air and incomplete rotation of a fan can be prevented. ;SOLUTION: Inner circumferential surface of a fan scrolling casing 7 is constituted of a partial arc concentric to the outer circumferential surface of a centrifugal fan fixed with three blades 16. Inside diameter of an air inlet is made constant in the ventilating direction. Since intricate operations are not required in the design of the fan scrolling casing 7 and the air inlet and the number of parts is decreased, manufacturing cost can be reduced. Since the interval between the inner circumferential surface of the fan scrolling easing 7 and the outer circumferential surface of the centrifugal fan is not extremely limited partially, clogging with foreign matter, e.g. dust, is eliminated. Furthermore, the centrifugal fan is prevented from abutting against the inner circumferential surface of the fan scrolling casing 7 due to error in the dimensions of the centrifugal fan or the fixing position thereof.;COPYRIGHT: (C)2001,JPO