External fan

Abstract

An external fan is mounted on a chassis and includes a retaining stage and a ceramic axis. The retaining stage is arranged on one external side of the chassis and includes a base and a hollow rod erecting on the base. A stator is arranged outside the hollow rod. The ceramic axis passes into the hollow rod and includes a first end connected to a rotator wrapped outside the stator and a second end extending out of a bottom of the base and connected to a blade inside the chassis.

1 . An external fan mounted on a chassis, comprising: 
 a retaining stage arranged on one external side of the chassis and comprising a base and a hollow rod erecting on the base, a stator arranged outside the hollow rod; and    a ceramic axis passing into the hollow rod and comprising a first end connected to a rotator wrapped outside the stator and a second end extending out of a bottom of the base and connected to a blade inside the chassis.    
   
   
       2 . The external fan as in  claim 1 , wherein the base comprises a plurality of flanges, each of the flanges comprises a clamping hole through which a screwing member is engaged.  
   
   
       3 . The external fan as in  claim 1 , wherein the hollow rod comprises a plurality of bearings therein and capped on the ceramic axis.  
   
   
       4 . The external fan as in  claim 1 , wherein the second end of the ceramic axis comprises a thread portion for screwing to the blade.  
   
   
       5 . The external fan as in  claim 4 , wherein a spiral direction of the thread portion is opposite to a rotation direction of the rotator.  
   
   
       6 . The external fan as in  claim 1 , wherein the blade is extended from a portion near the ceramic axis.