Patent ID: 7632063
Filing Date: 2009-12-15
Classification: F04D,Y10S

Abstract:
1. A fan comprising: a plurality of blades extending in a radial direction with respect to a rotation axis; a ring portion disposed on radial outside edges of the blades, wherein a portion of the radial outside edge of each of the blades protrudes from the ring portion toward an upstream position with respect to a flow direction of air, the ring portion including an annular wall extending generally parallel to the rotation axis and an extending portion extending from an upstream end of the annular wall in a radial outward direction; a first connecting wall extending between the ring portion and the portion of the radial outside edge of the blade; and a second connecting wall having a generally triangular shape, wherein the second connecting wall extends from the first connecting wall and connects to the ring portion on a leading side of the first connecting wall with respect to a rotation direction of the blade.