Method and apparatus for producing radially oriented ring magnet

Abstract

The present invention provides a method and an apparatus for producing radially oriented ring magnet. The problem it solved is to uniformly orient the magnet powder in the process of producing, and also to get relatively large oriented magnetic field strength, so as to increase the performance and uniformity of the radial ring. The method of forming a radially oriented ring magnet, is to position magnetic powder into a ring mold, using an oriented magnetic field to orient the magnetic powder in the ring mold along the radius or diameter direction, wherein the oriented magnetic field is distributed discretely 360° around the ring mold, and during the forming process the oriented magnetic field and the magnetic powder have relative rotation. The apparatus comprises a ring mold cavity positioned in an oriented magnetic field, wherein the oriented magnetic field is distributed discretely 360° around the ring mold, and the apparatus comprises a component fot the oriented magnetic field and the magnetic powder to rotate relatively. Because the magnetic field is the same field in 360°, the orienting of the magnetic powder is more complete, the orientation in different directions is more unified.

1 . A method for forming radially oriented ring magnet, comprising the steps of:
 (a) positioning a magnetic powder in a ring mold cavity; and   (b) radially orienting said magnetic powder in said ring mold cavity by a oriented magnetic field along radius or diameter direction, wherein said oriented magnetic field is distributed discretely 360° around said ring mold cavity, and during said forming process said oriented magnetic field and said magnetic powder have relative rotation.   
   
   
       2 . A method for forming radially oriented ring magnet, comprising the steps of:
 (a) applying a relatively small pressure onto a magnetic powder in a mold cavity to reduce the volume of said magnetic powder to 5% to 40%;   (b) introducing a magnetic field to the poles of an oriented magnetic field, rotating said magnetic powder in said mold cavity relating to said oriented magnetic field until said magnetic powder is totally magnetized;   (c) reducing the magnetic field strength of said oriented magnetic field until zero during rotating;   (d) applying more pressure on said magnetic powder until a predetermined level; and   (e) applying a reverse magnetic field to a radial ring bodyware for demagnetization, receiving said radial ring bodyware.   
   
   
       3 . An apparatus for forming radially oriented ring magnet, comprising a ring mold cavity in said oriented magnetic field, wherein said oriented is distributed discretely 360° around said ring mold cavity, and during said forming process said oriented magnetic field and said magnetic powder have relative rotation. 
   
   
       4 . The apparatus, as recited in  claim 3 , wherein said oriented magnetic field is a flake parallel magnetic field or a near parallel magnetic field. 
   
   
       5 . The apparatus, as recited in  claim 4 , wherein the width of said oriented magnetic field in the diameter direction is less than the inner diameter of said mold cavity. 
   
   
       6 . The apparatus, as recited in  claim 5 , wherein the width of said oriented magnetic field in the diameter direction is less than the one fifth of the inner diameter of said mold cavity. 
   
   
       7 . The apparatus, as recited in  claim 6 , wherein an inner pole of said oriented magnetic field is located in the center of said ring mold cavity, an outer pole of said oriented magnetic field is located in the outside of said ring mold cavity, wherein said apparatus comprises a magnetic conductive plate located inside said outer pole, and a strong magnetic field between said inner pole and said magnetic conductive plate. 
   
   
       8 . The apparatus, as recited in  claim 7 , wherein comprises more than one set of inner pole and magnetic conductive plate. 
   
   
       9 . The apparatus, as recited in  claim 8 , wherein said mold cavity and said inner pole of said oriented magnetic field are fixed, said outer pole of said oriented magnetic field and said magnetic conductive plate are connected with a rotation driver; or said outer pole and said magnetic conductive plate are fixed, said mold cavity and said inner pole are connected with said rotation driver. 
   
   
       10 . The apparatus, as recited in  claim 6 , wherein said first outer pole and said second outer pole of said oriented magnetic field are positioned at the outside of said ring mold cavity facing to each other, wherein said ring mold cavity further comprises a magnetic conductive core located at the center thereof, wherein said apparatus comprises two strong magnetic fields respectively between said magnetic conductive core and said first outer pole, and between said magnetic conductive core and said second outer pole. 
   
   
       11 . The apparatus, as recited in  claim 10 , wherein said mold cavity of said oriented magnetic field and said magnetic conductive core are fixed, said first outer pole and said second outer pole of said oriented magnetic field are connected with a rotation driver; or said first outer pole and said second outer pole of said oriented magnetic field are fixed, said mold cavity and said magnetic conductive core are connected with said rotation driver. 
   
   
       12 . The apparatus, as recited in  claim 11 , wherein said first outer pole and said second outer pole are more than one pair. 
   
   
       13 . The apparatus, as recited in  claim 11 , wherein said first outer pole and said second outer pole have an odd number.