Fan structure

Abstract

A fan structure includes a frame having an inner surface, a permeable element covering the inner surface of the frame, a coil surrounded by the permeable element and a rotor assembly disposed rotatably in the frame. The rotor assembly includes a plurality of blades coupled to a shaft and a permanent magnet enclosing the blades and facing the coil. The rotor assembly rotates along the shaft to generate airflow by means of the electromagnetic effect between the permanent magnet and the coil.

1 . A fan structure comprising:
 a frame having an inner surface;   a permeable element covering the inner surface of the frame;   a coil surrounded by the permeable element; and   a rotor assembly rotatably disposed in the frame, wherein the rotor assembly comprises:
 a plurality of blades coupled to a shaft; and 
 a permanent magnet enclosing the blades and facing the coil, 
   wherein the rotor assembly rotates about the shaft to generate air flow by means of the electromagnetic effect between the permanent magnet and the coil.   
     
     
         2 . The fan structure as claimed in  claim 1 , wherein the size of an outer peripheral surface of the coil corresponds to the size of an inner peripheral surface of the permeable element. 
     
     
         3 . The fan structure as claimed in  claim 2 , wherein the coil is in an annular shape and the inner peripheral surface of the permeable element is tubular, and the outer diameter of the coil corresponds to the inner diameter of the permeable element. 
     
     
         4 . The fan structure as claimed in  claim 3 , wherein the outer peripheral surface of the coil abuts the inner peripheral surface of the permeable element. 
     
     
         5 . The fan structure as claimed in  claim 3 , wherein the permanent magnet is in an annular shape and faces an inner side of the coil. 
     
     
         6 . The fan structure as claimed in  claim 5 , wherein the blades have a plurality of outer edges connected to a peripheral ring, and the permanent magnet is connected to the peripheral ring and rotates along the shaft. 
     
     
         7 . The fan structure as claimed in  claim 6 , wherein the rotor assembly further comprises an iron ring disposed between the peripheral ring and the permanent magnet. 
     
     
         8 . The fan structure as claimed in  claim 6 , further comprising a sleeve and a bearing received in the sleeve for supporting the shaft. 
     
     
         9 . The fan structure as claimed in  claim 8 , wherein the peripheral ring, the blades and the sleeve are formed as a single piece. 
     
     
         10 . The fan structure as claimed in  claim 1 , wherein the permeable element is a silicon steel plate set, and the permeable element is formed with the frame as a single piece. 
     
     
         11 . The fan structure as claimed in  claim 10 , wherein the frame covers the silicon steel plate set by injection molding. 
     
     
         12 . The fan structure as claimed in  claim 11 , wherein the frame is made from plastic material. 
     
     
         13 . The fan structure as claimed in  claim 1 , wherein the coil is made by a winding method of the three-phase slotless motor. 
     
     
         14 . The fan structure as claimed in  claim 1 , wherein the frame is made from a permeable material or a plastic material. 
     
     
         15 . A fan structure comprising:
 a frame, made from permeable material, having an inner surface;   a coil surrounded by the inner surface of the frame; and   a rotor assembly rotatably disposed in the frame, wherein the rotor assembly comprises:
 a plurality of blades coupled to a shaft; and 
 a permanent magnet enclosing to the blades and facing the coil, 
   wherein the rotor assembly rotates about the shaft to generate air flow by means of the electromagnetic effect between the permanent magnet and the coil.   
     
     
         16 . The fan structure as claimed in  claim 15 , wherein the coil is in an annular shape, and the outer diameter of the coil corresponds to the inner diameter of the frame. 
     
     
         17 . The fan structure as claimed in  claim 16 , wherein the permanent magnet is in an annular shape and corresponds to an inner side of the coil, and the blades have a plurality of outer edges connected to a peripheral ring of the fan structure, and the permanent magnet connects to the peripheral ring and rotates along the shaft. 
     
     
         18 . The fan structure as claimed in  claim 17 , wherein the permanent magnet is connected to the peripheral ring by a tight fit. 
     
     
         19 . The fan structure as claimed in  claim 18 , wherein the rotor assembly further comprises an iron ring disposed between the peripheral ring and the permanent magnet. 
     
     
         20 . The fan structure as claimed in  claim 15 , wherein the coil is made by a winding method of the three-phase slotless motor.