Fan structure

Abstract

A fan structure includes a sleeve, an impeller, a bearing and a fixing shaft, wherein the sleeve is covered with a hub of the impeller. The sleeve comprises a ring wall, an accommodating slot and a top portion, and a penetration hole is formed at the top portion. The bearing is disposed at the accommodating slot and comprises an axial hole and a top surface, wherein the top surface of the bearing and the top portion are spaced apart from each other by an interval. The fixing shaft penetrates through the axial hole of the bearing, a free end of the fixing shaft is protruded to the top portion via the penetration hole, and an oil storage space can be defined between the top portion of the sleeve, the top surface of the bearing and the fixing shaft. Mentioned oil storage space may prevent lubricants from splashing

What is claimed is: 
     
         1 . A fan structure including:
 a cap having an accommodating space;   a sleeve having a ring wall, an accommodating slot surrounded by the ring wall and a top portion in connection with the ring wall, wherein a penetration hole communicated with the accommodating slot is formed at the top portion, and the ring wall is accommodated within the accommodating space of the cap;   an impeller having a hub for covering the sleeve;   a bearing having an axial hole and a top surface facing toward the top portion of the sleeve, the bearing is disposed at the accommodating slot of the sleeve, the top surface and the top portion are spaced apart from each other by an interval; and   a fixing shaft having a free end protruded to the top portion via the penetration hole and a fixing end coupled to the cap, wherein the fixing shaft penetrates through the axial hole of the bearing, and an oil storage space can be defined between the top portion of the sleeve, the top surface of the bearing and the fixing shaft.   
     
     
         2 . The fan structure in accordance with  claim 1 , wherein the fixing shaft further comprises a slot in communication with the oil storage space. 
     
     
         3 . The fan structure in accordance with  claim 1 , wherein the sleeve comprises a first lodge portion formed at the ring wall, the hub of the impeller comprises a second lodge portion, and the first lodge portion is cladded by the second lodge portion. 
     
     
         4 . The fan structure in accordance with  claim 3 , wherein the first lodge portion comprises a first protrusion, the second lodge portion comprises a first recess, and the first protrusion is cladded by the first recess. 
     
     
         5 . The fan structure in accordance with  claim 4 , wherein the first lodge portion comprises a second recess, the second lodge portion comprises a second protrusion cladded by the second recess. 
     
     
         6 . The fan structure in accordance with  claim 3 , wherein the first lodge portion comprises a second recess, the second lodge portion comprises a second protrusion cladded by the second recess. 
     
     
         7 . The fan structure in accordance with  claim 2  further includes a limiting member fastened at the slot of the fixing shaft, wherein the limiting member is located between the top portion and the bearing. 
     
     
         8 . The fan structure in accordance with  claim 1  further includes a stirring layer, wherein the ring wall comprises an inner surface, and the stirring layer is formed on the inner surface. 
     
     
         9 . The fan structure in accordance with  claim 1  further includes a stirring layer, wherein the top portion comprises an interior surface, and the stirring layer is formed on the interior surface. 
     
     
         10 . The fan structure in accordance with  claim 1  further includes a stirring layer formed on the top surface of the bearing. 
     
     
         11 . The fan structure in accordance with  claim 2  further includes a stirring layer formed at the slot of the fixing shaft. 
     
     
         12 . The fan structure in accordance with  claim 3 , wherein the first lodge portion of the sleeve is cladded by the second lodge portion of the impeller by means of injection molding. 
     
     
         13 . The fan structure in accordance with  claim 1 , wherein the material of the sleeve is different from that of the impeller. 
     
     
         14 . The fan structure in accordance with  claim 1 , wherein the ring wall comprises an inner surface and a blocking member disposed on the inner surface. 
     
     
         15 . The fan structure in accordance with  claim 14 , wherein the bearing is in contact against the blocking member. 
     
     
         16 . The fan structure in accordance with  claim 14 , wherein the blocking member is protruded to the inner surface of the ring wall, and the blocking member is ring shaped.