Axial fan

Abstract

An axial fan includes an impeller. The impeller includes a hub and a plurality fan blades connected with the hub. Each fan blade includes a mounting portion provided at an inner edge thereof. The mounting portion defines a slot therein. A fastener extends through the slot of the mounting portion to fix each fan blade to the hub. An angle is defined between each fan blade and a central axis of the axial fan. The angle is capable of being regulated when each fan blade is rotated relative to the hub to cause the fastener to slide in the slot of the mounting portion.

1 . An axial fan, comprising:
 an impeller comprising a hub and a plurality fan blades connected with the hub, each fan blade comprising a mounting portion provided at an inner edge thereof, the mounting portion defining a slot therein; and   a fastener extending through the slot of the mounting portion to fix each fan blade to the hub, an angle being defined between each fan blade and a central axis of the axial fan, the angle being capable of being regulated when each fan blade is rotated relative to the hub to cause the fastener to slide in the slot of the mounting portion.   
     
     
         2 . The axial fan of  claim 1 , wherein the mounting portion comprises two mounting ears symmetrically disposed at two opposite sides of the inner edge of the fan blade, respectively, the slot being divided into two sections, and the two sections are provided in the two mounting ears, respectively. 
     
     
         3 . The axial fan of  claim 2 , wherein the two sections of the slot each are arc-shaped. 
     
     
         4 . The axial fan of  claim 3 , wherein the two sections of the slot in the mounting portion of each fan blade are located on an imaginary circle and have a common center of circle. 
     
     
         5 . The axial fan of  claim 2 , wherein the hub comprises a base plate and a sidewall extending perpendicularly from an outer periphery of the base plate, and the mounting ears are fittingly abutted on an outer surface of the sidewall of the hub. 
     
     
         6 . The axial fan of  claim 5 , wherein a plurality of rods is formed on an inner surface of the sidewall along the central axis of the axial fan. 
     
     
         7 . The axial fan of  claim 1 , wherein a mounting hole is defined through the hub corresponding to the slot, and the fastener extends through the slot and the mounting hole to fix each fan blade on the hub. 
     
     
         8 . The axial fan of  claim 1 , wherein the slot comprises at least an arc-shaped section. 
     
     
         9 . The axial fan of  claim 1 , wherein the fastener is a screw. 
     
     
         10 . The axial fan of  claim 1 , further comprising a fan frame, the fan frame comprising an annular ring, a plurality of supporting poles extending from the annular ring, a mounting base disposed above the annular ring, and a plurality of connecting ribs connecting the mounting base with free ends of the supporting poles. 
     
     
         11 . The axial fan of  claim 10 , wherein an air inlet is formed at a top of the fan frame, an air outlet is formed at a bottom of the fan frame opposite to the air inlet, and the mounting base is disposed at a center of the air inlet. 
     
     
         12 . The axial fan of  claim 11 , wherein the impeller is mounted in the fan frame and coupled to the mounting base.