Abstract: Front edges 212b of blades 212 are so constituted as to be deviated toward the upstream side in the air stream beyond an axial end surface 211a, as viewed from a direction at right angles to the axial direction of a boss 211, and the blades 212 on the root side thereof are continuous to the axial end surface 211a through smoothly curved surfaces 213. This enables the air to flow from the side of the axial end surface 211a toward the root side of the blades 212. Due to the air flowing from the side of the axial end surface 211a to the root side of the blades 212, therefore, the resistance decreases between the air and the surfaces of the blades 212 on the root side, making it possible to suppress the occurrence of stalling on the root side of the blades 212. The air on the front side of the boss 211 is effectively guided toward the outer direction (toward the blades 212), preventing a drop in the flow rate and in the fan efficiency of a blower 200.

Abstract: Front edges 212b of blades 212 are so constituted as to be deviated toward the upstream side in the air stream beyond an axial end surface 211a, as viewed from a direction at right angles to the axial direction of a boss 211, and the blades 212 on the root side thereof are continuous to the axial end surface 211a through smoothly curved surfaces 213. This enables the air to flow from the side of the axial end surface 211a toward the root side of the blades 212. Due to the air flowing from the side of the axial end surface 211a to the root side of the blades 212, therefore, the resistance decreases between the air and the surfaces of the blades 212 on the root side, making it possible to suppress the occurrence of stalling on the root side of the blades 212. The air on the front side of the boss 211 is effectively guided toward the outer direction (toward the blades 212), preventing a drop in the flow rate and in the fan efficiency of a blower 200.