Fan assembly

Abstract

A fan assembly includes a fan hub. The fan hub has a body. The body includes a top surface and a bottom surface opposite to the top surface. The top surface defines a first recess towards the bottom surface.

What is claimed is: 
     
         1 . A fan assembly comprising:
 a fan hub having a body comprising a top surface and a bottom surface opposite to the top surface, wherein the top surface defines a first recess towards the bottom surface.   
     
     
         2 . The fan assembly of  claim 1 , wherein the bottom surface defines a second recess towards the top surface, the first recess and the second recess are spaced apart from each other. 
     
     
         3 . The fan assembly of  claim 2 , further comprising a plurality of fans, wherein the fans extend outside from the body radically. 
     
     
         4 . The fan assembly of  claim 3 , further comprising a shaft, wherein the second recess comprises a bottom surface, the bottom surface is parallel to the bottom surface of the body, the shaft protrudes from the bottom surface of the second recess towards the bottom surface of the body. 
     
     
         5 . The fan assembly of  claim 4 , wherein the shaft and the body are coaxial. 
     
     
         6 . The fan assembly of  claim 4 , further comprising a fan box, a bearing group, and a stator group, wherein the fan box comprises a frame and a bearing block, the frame comprises an upper surface and a lower surface opposite to the upper surface, the upper surface defines a receiving space towards the lower surface, the bearing block is located at a center of the receiving space and is adjacent to the lower surface, the fan box further comprises a shaft tube protruding from a center of the bearing block towards the upper surface, the shaft tube runs through the stator group, the stator group is fixed on the bearing block, the shaft tube defines a through hole to receive the bearing group, the fan hub is received in the receiving space and is fixed on the bearing block, the shaft runs into the bearing group. 
     
     
         7 . The fan assembly of  claim 6 , wherein the bearing group comprises a magnetic absorption structure, the magnetic absorption structure comprises a magnet and a magnetic yoke, the magnet is received in the magnetic yoke, a surface of the magnet adjacent to the upper surface is exposed from the magnetic yoke and is aligned with the shaft. 
     
     
         8 . The fan assembly of  claim 6 , wherein the fan box further comprises a connecting part, the connecting part is received in the receiving space and is adjacent to the lower surface, the connecting part is connected between the frame and the bearing block, the connecting part comprises a plurality of connecting arms, at least one connecting arms defines a slot to receive electric wires. 
     
     
         9 . The fan assembly of  claim 8 , wherein the connecting arms are equally spaced from each other. 
     
     
         10 . The fan assembly of  claim 1 , further comprising a top cover, fixed on the top surface and sealing the first recess to define an air insulation layer. 
     
     
         11 . The fan assembly of  claim 10 , wherein the top cover has a disc shape. 
     
     
         12 . The fan assembly of  claim 10 , wherein the top cover has a bullet shape.