Patent ID: 9261107
Filing Date: 2016-02-16
CPC Classification: F04D

Claim Text:
1. A centrifugal fan comprising: a disc-shaped base to which a motor shaft is coupled; a plurality of blades spaced apart from one another in a circumferential direction of the base to guide axially introduced air in a circumferential direction of the base, each blade including a pressure surface to push the air, a negative pressure surface opposite to the pressure surface, a leading edge toward the motor shaft, and a trailing edge toward an outer circumference of the base; a main shroud extending in a radial outward direction of the base from a circumscribed circle defined by connecting upper ends of the trailing edges of the plurality of blades; and a sub shroud extending forward of the pressure surface from a position where each of the plurality of blades comes into contact with the main shroud and serving to prevent the air from moving from the pressure surface to the negative pressure surface by passing over an upper end of the trailing edge of each blade, wherein the sub shroud horizontally extends to form a protruding corner having a predetermined area formed from where the pressure surface of each blade comes into contact with an inner-diameter portion of the main shroud, the base is provided with a cut-out from an outer circumference of the base extending radially inward, and the cut-out extends through the outer circumference of the base.