Patent ID: 8870541
Filing Date: 2014-10-28
Classification: F04D

Abstract:
1. A centrifugal multiblade fan for drawing air from one end side of the fan in an axial direction of the fan and for blowing out the air radially outward of the fan, the fan comprising: a rotatable shaft; a plurality of blades arranged around the rotatable shaft, wherein: a side shroud coupling together respective end portions of the plurality of blades on the one end side; and a main shroud joined to the rotatable shaft and coupling together respective end portions of the plurality of blades on the other end side of the fan in the axial direction, wherein: when viewed from the axial direction, the corner part on the positive pressure surface-side is located on a tangential line of the positive pressure surface reference curve at the positive pressure surface side reference corner part, and when viewed from the axial direction, a curvature radius of the negative pressure surface becomes larger in the axial direction from the side shroud toward the main shroud when a comparison is made between the curvature radius of the negative pressure surface at a side shroud side portion and the curvature radius of the negative pressure surface at a main shroud side portion, the side shroud side portion and the main shroud side portion are located at the same position in a radial direction of the fan.