Axial fan

Abstract

An axial fan includes a fan frame, a motor and a fan wheel. The fan frame comprises an outer frame body and a mounting portion, wherein the outer frame body and the mounting portion are connected by a plurality of ribs. The motor is disposed at the mounting portion and has at least a cable across the outer frame body and the mounting portion, wherein at least a first rib of the ribs has an airflow mitigation structure. The motor is connected to the fan wheel.

What is claimed is: 
     
         1 . An axial fan comprising:
 a fan frame comprising an outer frame body and a mounting portion, wherein the outer frame body and the mounting portion are connected by a plurality of ribs;   a motor disposed on the mounting portion, and having an electrical connection cable spanning between the outer frame body and the mounting portion, wherein a first rib of the ribs closest to the electrical connection cable has an airflow mitigation structure; and   an impeller pivotally connected to the motor.   
     
     
         2 . The axial fan of  claim 1 , wherein the impeller is driven by the motor to rotate such that airflows are input from an air inlet side of the fan frame and output from an air outlet side of the fan frame, the airflow mitigation structure is located at the air inlet side of the first rib. 
     
     
         3 . The axial fan of  claim 1 , wherein the airflow mitigation structure is located at a side of the first rib closer to the electrical connection cable. 
     
     
         4 . The axial fan of  claim 1 , wherein two sides of a connection between each of the ribs and the outer frame body have arc-shaped chamfers. 
     
     
         5 . The axial fan of  claim 1 , wherein the ribs, except for the first rib, comprises a plurality of second ribs having airflow guiding inclined surfaces. 
     
     
         6 . The axial fan of  claim 1 , wherein the electrical connection cable comprises a flexible printed circuit board. 
     
     
         7 . The axial fan of  claim 2 , wherein an axial flow channel is defined among the outer frame body, the mounting portion and the ribs, the outer frame body has a chamfered peripheral edge at an inner edge of the air outlet side facing the axial flow channel. 
     
     
         8 . The axial fan of  claim 1 , wherein the ribs include three ribs, and three central angles, formed by lines connecting the three ribs and a center of the mounting portion, are not equal. 
     
     
         9 . The axial fan of  claim 1 , wherein the impeller includes a plurality of blades, and gap widths between free ends of the blades have three different sizes. 
     
     
         10 . The axial fan of  claim 9 , wherein a windward side of each blade has a plurality of convex flow-guiding structures. 
     
     
         11 . An axial fan comprising:
 a fan frame comprising an outer frame body and a mounting portion, wherein the outer frame body and the mounting portion are connected by a plurality of ribs;   a motor disposed on the mounting portion, and having an electrical connection cable overlapping a first rib of the ribs; and   an impeller pivotally connected to the motor.   
     
     
         12 . The axial fan of  claim 11 , wherein the first rib has a greater width than that of the other ribs of the ribs. 
     
     
         13 . The axial fan of  claim 11 , wherein the ribs, except for the first rib, comprises a plurality of second ribs having airflow guiding inclined surfaces. 
     
     
         14 . The axial fan of  claim 11 , wherein the first rib has a greater width than that of the electrical connection cable. 
     
     
         15 . The axial fan of  claim 11 , wherein the impeller includes a plurality of blades, and a windward side of each blade has a plurality of convex flow-guiding structures.