Fan and impeller thereof

Abstract

A fan has an impeller, a motor and a frame. The impeller and the motor are disposed within the frame, and the motor is connected to the impeller and drives the impeller to rotate. The impeller includes a hub and an odd number of blade sets. The blade sets are disposed around the circumference of the hub. Bach blade set has a plurality of the blades, and the blades of each blade set can be the same or not. For example, the blades in each of the blade sets have different tilting angles, heights and/or lengths while the blades are connected with the hub. Or the blades in each of the blade sets have different curvatures, arc lengths, thicknesses, or side-view shapes.

1 . An impeller, comprising:
 a hub; and   an odd number of blade sets disposed around a circumference of the hub, wherein each of the blade sets comprises a plurality of blades.   
   
   
       2 . The impeller of  claim 1 , wherein all blades in each of the blade sets are the same. 
   
   
       3 . The impeller of  claim 1 , wherein the blades in each of the blade sets are different. 
   
   
       4 . The impeller of  claim 3 , wherein the blades in each of the blade sets have different tilting angles, heights and/or lengths while the blades are connected with the hub. 
   
   
       5 . The impeller of  claim 3 , wherein the blades in each of the blade sets have different intervals between two adjacent blades. 
   
   
       6 . The impeller of  claim 3 , wherein the blades in each of the blade sets have different curvatures, arc lengths, thicknesses, or side-view shapes. 
   
   
       7 . The impeller of  claim 3 , wherein numbers of the blades in each of the blade sets are the same. 
   
   
       8 . The impeller of  claim 7 , wherein the blades in each of the blade sets are disposed corresponding to the blades in another blade set. 
   
   
       9 . The impeller of  claim 1 , wherein the blade sets are disposed around the circumference of the hub with equal intervals. 
   
   
       10 . The impeller of  claim 1 , wherein adjacent blades in each of the blade sets are partially overlapped with each other. 
   
   
       11 . The impeller of  claim 1 , further comprising at least one reinforcing element connected to all of the blade sets, wherein the reinforcing element is ring-shaped. 
   
   
       12 . A fan comprising:
 an impeller, comprising a hub and an odd number of blade sets disposed around a circumference of the hub, wherein each of the blade sets comprises a plurality of blades;   a motor connected to the impeller and driving the impeller to rotate; and   a frame, wherein the impeller and the motor are disposed in the frame.   
   
   
       13 . The fan of  claim 12 , wherein all blades in each of the blade sets are the same. 
   
   
       14 . The fan of  claim 12 , wherein the blades in each of the blade sets are different. 
   
   
       15 . The fan of  claim 14 , wherein the blades in each of the blade sets have different tilting angles, heights and/or lengths while the blades are connected with the hub. 
   
   
       16 . The fan of  claim 14 , wherein the blades in each of the blade sets have different intervals between two adjacent blades. 
   
   
       17 . The fan of  claim 14 , wherein the blades in each of the blade sets have different curvatures, arc lengths, thicknesses, or side-view shapes. 
   
   
       18 . The fan of  claim 14 , wherein numbers of the blades in each of the blade sets are the same, and the blades in each of the blade sets are disposed corresponding to the blades in another blade set. 
   
   
       19 . The fan of  claim 12 , wherein adjacent blades in each of the blade sets are partially overlapped with each other. 
   
   
       20 . The fan of  claim 12 , wherein the impeller further comprises at least one reinforcing element connected to all of the blade sets, and the reinforcing element is ring-shaped.