Permanent magnet motor

Abstract

A rotor for a permanent magnet motor includes a rotor body and a plurality of permanent magnets carried by the rotor body. The rotor body has an outside rotor surface with a plurality of dovetail slots formed on the outside rotor surface. Each magnet is fit within one of the slots, protruding outward of the outside rotor surface in a radial direction. According to another embodiment, a rotor is provided having a rotor body that carries a plurality of magnets on its outside surface, and end caps that are fastened respectively to longitudinal ends of the rotor body. The end caps each have a angled rim surfaces that overhangs an end portion of the outer magnet surface of each of the magnets to retain the magnets onto the rotor body. The angled rim surfaces and the magnets can be configured such that by drawing the end caps tightly against the rotor body by use of fasteners, the magnets are wedged down onto the rotor body by the angled rim surfaces.

1 . (canceled)  
   
   
       2 . (canceled)  
   
   
       3 . (canceled)  
   
   
       4 . (canceled)  
   
   
       5 . (canceled)  
   
   
       6 . (canceled)  
   
   
       7 . (canceled)  
   
   
       8 . (canceled)  
   
   
       9 . (canceled)  
   
   
       10 . (canceled)  
   
   
       11 . (canceled)  
   
   
       12 . (canceled)  
   
   
       13 . (canceled)  
   
   
       14 . A method of manufacturing a permanent magnet motor having a rotor turned by magnetic interaction with a stator, comprising the steps of: 
 forming a rotor body with an outside rotor surface, and a plurality of slots formed on said outside rotor surface, each slot having a flat bottom and side walls converging in an outward radial direction; and    forming a plurality of permanent magnets, each magnet having a curved outer magnet surface, and a flat bottom surface wherein said magnets are sized and shaped to partially fit within said slots;    longitudinally sliding said magnets into said slots, wherein when said magnets are inserted into said slots, said outside rotor surface has a discontinuous cylindrical rotor surface between said slots and said outer magnet surfaces define a discontinuous cylindrical magnet surface that protrudes outward of said discontinuous cylindrical rotor surface in a radial direction; and    installing said rotor within said stator with said outer magnet surfaces exposed to an inside surface of said stator with a close tolerance gap.    
   
   
       15 . The rotor according to  claim 14 , comprising the further step of applying adhesive between said magnets and said slots before said magnets are fit in said slot.  
   
   
       16 . In a permanent magnet motor having a rotor turned by magnetic interaction with a stator, the rotor comprising: 
 a rotor body with an outside rotor surface, a plurality of slots formed on said outside rotor surface, said slots being dovetail-shaped in cross section along a longitudinal direction of said rotor body, each slot having a flat bottom and contiguous, opposite side walls converging in an outward radial direction; and    a plurality of permanent magnets, each of said magnets of said plurality partially fit within a corresponding one of said slots, each magnet having a curved outer magnet surface protruding outward of said outside rotor surface in a radial direction, and a flat bottom surface, wherein said magnets have correspondingly dovetail-shaped base portions to be tightly longitudinally slid into said slots, said outside rotor surface has a discontinuous cylindrical rotor surface between slots and an aggregate of said outer magnet surfaces defines a discontinuous cylindrical magnet surface that protrudes outward of said discontinuous cylindrical rotor surface in a radial direction, said outer magnet surface and said outside rotor surface exposed to said stator.    
   
   
       17 . The rotor according to  claim 16 , wherein said magnets are adhesively secured within said slots.  
   
   
       18 . The rotor according to  claim 16 , wherein said side walls converge in a tangential direction taken in an outward radial direction.  
   
   
       19 . The rotor according to  claim 16  wherein said magnets have a longer radial length than said slots.  
   
   
       20 . A method of manufacturing a permanent magnet motor having a rotor turned by magnetic interaction with a stator, comprising the steps of: 
 forming a rotor body with an outside rotor surface;    providing a plurality of permanent magnets;    fitting said plurality onto said outside rotor surface, each magnet having an outer magnet surface; and    providing first and second end caps and fastening said end caps to longitudinal ends of said rotor body, said end caps having rims that overhang end portions of said outer magnet surface of each of said magnets to retain said magnets onto said rotor body.    
   
   
       21 . The method according to  claim 20 , comprising the further step of adhesively securing said magnets to said outside rotor surface.  
   
   
       22 . The method according to  claim 20 , wherein said rims each include angled rim surfaces at each magnet facing said outer magnet surface, each angled rim surface being angled in an outward radial direction obliquely toward the respective other rim, and said outer magnet surface of each magnet includes an angled surface portion at each longitudinal end of said outer magnet surface, said angled surface portions at each longitudinal end of each magnet being fit flushly against said angled rim surface of one of said rims of said first and second end caps.  
   
   
       23 . The method according to  claim 22 , wherein said angled rim surface of each rim is annular.  
   
   
       24 . The method according to  claim 23 , wherein said outer magnet surfaces define a discontinuous cylindrical surface having a maximum diameter and an outer surface of each of said end caps has an end cap diameter equal to said maximum diameter.  
   
   
       25 . The method according to  claim 20 , wherein said step of providing said plurality of magnets is further defined in that said outer magnet surfaces when installed on said outside rotor surface define a discontinuous cylinder.