Abstract: A blower includes a plurality of rotatable impeller vanes operable to impel air. The impeller vanes create an air pressure differential thereacross when rotated, and each of the impeller vanes has a porous central portion made of sintered resin material. The porous central portion has a plurality of pores therein which permit a portion of air to pass through the porous central portion from a relatively high air pressure side to a relatively low air pressure side of the impeller vanes. Each of the impeller vanes also has a non-porous portion surrounding the porous central portion. The non-porous portion is made of a solid resin material which prevents air from passing therethrough.

Abstract: An impeller of a multiblade blower having at least two circular end plates or partition plates spaced apart from each other, and a plurality of blades disposed between the peripheral portions of the partition plates. Each of the blades is formed with a cylindrical portion having a uniform cross-sectional area, at the outer peripheral end thereof on the outer peripheral side of the impeller. The cylindrical portion has a diameter which is larger than the thickness of the blade at the outer peripheral end thereof so that the cylindrical portion is projected from both front and rear surfaces of the blade at the outer peripheral end of the latter.

Abstract: An airfoil blade for a fan impeller, includes one blade surface portion formed by extrusion molding. A plurality of ribs are integrally formed with the one blade surface portion to extend upwardlyf rom it in generally a vertical direction and having heights as will provide a curve line for the other curved blade surface portion when end faces of the ribs are connected to each other. A sheet material is applied onto the ribs along their end faces to provide the other curved blade surface portion so as to form a blade configuration of the airfoil blade having a leading edge and a trailing edge and including hollow portions in it.

Abstract: The disclosure is directed to a mixed flow impeller with a low noise, to be used for a blower of an air conditioner or the like. The mixed flow impeller of the present invention is characterized in three points, i.e., thin thickness blade member increased in its thickness only at its leading edge, a plate-like triangular protrusion provided at an outer peripheral portion of the leading edge, and blade curvature line having its maximum curvature position deviated toward the trailing edge side through employment of a cubic curve. Since each of the above features may be caused to function independently, noise reduction is possible even if it is executed singly, but the maximum effect is available when the are effected in combination.