Abstract:
A centrifugal fan is described. The fan uses a blade that is tapered across the span of the blade. The taper can be larger towards the end opposite of the inlet or larger at the inlet. The blade may be backwardly inclined and / or curved. The fan may also include a turning vane.
Abstract:
A blower (10) includes an impeller housing (18, 20), an impeller (12) rotatably secured to the housing and an electric motor (14). The motor has a motor housing (56) with a central portion (66) and a radially extending portion (64)extending from the central portion, a venturi chamber (809) adjacent the motor housing and opposed to the impeller housing, a stator (30) secured to the central portion of the motor housing, a rotor (32) rotatably secured to the central portion of the housing, and at least one heat generating electrical component (46) secured to the radially extending portion of the motor housing. The impeller housing has a first air pressure therein and the motor housing (56) has a second air pressure therein different that the first air pressure. The venturi housing and the motor housing define a passageway (883) therebetween whereby the difference in air pressure generates air flow within the motor housing to cool the at least one heat generating electrical component (46).