Rotary compressor with permanent magnet motor

Abstract

A rotary compressor comprising a rotor having a plurality of permanent magnets mounted thereon and a stator, where the rotor is aligned with respect to the stator via a magnetic attraction between the permanent magnets and the stator. The compressor includes a housing and is configured such that the rotor does not entirely bear against a top or bottom portion of the compressor housing. The permanent magnets of the rotor are sized and configured such that the magnetic attraction between the magnets and the stator, regardless of whether the stator is energized, positions, or suspends, the rotor substantially intermediate the top and bottom portions of the housing. As a result, less or, possibly, even no friction is experienced between the rotor and the compressor housing which reduces the potential for the rotor to seize or stall and allows the compressor to be operated with little or no oil.

1 . A rotary compressor, comprising: 
 a housing having a first surface and a second surface, said first surface spaced from said second surface;    a stator;    a pump mechanism; and    a rotor rotatably mounted within said housing and positioned within said stator, said rotor operably engaged with said pump mechanism, said rotor having at least one permanent magnet mounted thereto, said at least one permanent magnet magnetically attracted to at least a portion of said stator to hold said rotor intermediate said first surface and said second surface.    
   
   
       2 . The rotary compressor of  claim 1 , wherein said rotor is levitated between said first surface and said second surface by the magnetic attraction between said at least one permanent magnet and said stator.  
   
   
       3 . The rotary compressor of  claim 1 , wherein said stator includes windings, and wherein said rotor is held intermediate said first surface and said second surface regardless of whether said windings are energized.  
   
   
       4 . The rotary compressor of  claim 1 , wherein said rotor includes a top surface, a bottom surface, and an outer perimeter, and wherein said compressor includes a first gap between said first surface of said housing and said bottom surface of said rotor, a second gap between said second surface of said housing and said top surface of said rotor, and a third gap between said outer perimeter of said rotor and said stator.  
   
   
       5 . The rotary compressor of  claim 1 , wherein said pump mechanism includes a post, a roller orbited by said rotor with respect to said post, and a compression chamber intermediate said post and said roller for compressing a refrigerant.  
   
   
       6 . The rotary compressor of  claim 1 , wherein said at least one permanent magnet includes a plurality of permanent magnets evenly spaced about an outside perimeter of said rotor.  
   
   
       7 . A rotary compressor, comprising: 
 a housing having a top portion and a bottom portion;    a stator;    a rotor rotatably mounted in said housing, said rotor having a plurality of permanent magnets positioned around an outer periphery of said rotor, said rotor including a central cavity;    a post having an outer perimeter, said post being positioned within said central cavity and positioned intermediate said top plate and said bottom plate, said post further including a vane slot;    a vane slidably disposed within said vane slot; and    a roller having an inner perimeter, said roller positioned within said central cavity of said rotor such that said inner perimeter of said roller is eccentric with respect to said outer perimeter of said post, said vane being biased against said roller,    wherein said permanent magnets are magnetically attracted to said stator, whereby said rotor is axially aligned with said stator by said magnetic attraction.    
   
   
       8 . The rotary compressor of  claim 7 , wherein said roller is relatively rotatable with respect to said rotor, whereby said roller may rotate at a first speed with respect to said post and said rotor may rotate at a second speed with respect to said post.  
   
   
       9 . The rotary compressor of  claim 7 , wherein said first plate includes a shoulder extending therefrom having a bearing surface for aligning said rotor with respect to said stator.  
   
   
       10 . The rotary compressor of  claim 7 , wherein said rotor is held intermediate said top portion and said bottom portion of said housing by the magnetic attraction between said plurality of magnets and said stator.  
   
   
       11 . The rotary compressor of  claim 7 , wherein said rotor is levitated between said top portion and said bottom portion of said housing by the magnetic attraction between said plurality of magnets and said stator.  
   
   
       12 . The rotary compressor of  claim 7 , wherein the magnetic attraction between said plurality of magnets and said stator at least partially supports the weight of said rotor.  
   
   
       13 . A rotary compressor, comprising: 
 a housing;    a stator;    a pump mechanism; and    a rotor rotatably mounted within said housing and positioned within said stator, said rotor operably engaged with said pump mechanism, said rotor having at least one permanent magnet mounted thereto, said at least one permanent magnet magnetically attracted to at least a portion of said stator, said magnetic attraction at least partially supporting the weight of said rotor.    
   
   
       14 . The rotary compressor of  claim 13 , wherein said rotor is fully supported by the magnetic attraction between said at least one permanent magnet and said stator such that said rotor does not contact said housing.  
   
   
       15 . The rotary compressor of  claim 13 , wherein said housing includes a first surface and a second surface, said first surface spaced from said second surface, said magnetic attraction between said at least one permanent magnet and said stator holding said rotor intermediate said first surface and said second surface.  
   
   
       16 . The rotary compressor of  claim 15 , wherein said rotor is levitated between said first surface and said second surface by the magnetic attraction between said at least one permanent magnet and said stator.  
   
   
       17 . The rotary compressor of  claim 13 , wherein said stator includes windings and an iron core, and wherein said rotor is at least partially supported by the magnetic attraction between said at least one permanent magnet and said iron core of said stator regardless of whether said windings are energized.  
   
   
       18 . The rotary compressor of  claim 13 , wherein said housing includes a first surface and a second surface, wherein said rotor includes a top surface, a bottom surface, and an outer perimeter, and wherein said compressor includes a first gap between said first surface of said housing and said bottom surface of said rotor, a second gap between said second surface of said housing and said top surface of said rotor, and a third gap between said outer perimeter of said rotor and said stator.  
   
   
       19 . The rotary compressor of  claim 13 , wherein said pump mechanism includes a post, a roller orbited by said rotor with respect to said post, and a compression chamber intermediate said post and said roller for compressing a refrigerant.  
   
   
       20 . The rotary compressor of  claim 13 , wherein said at least one permanent magnet includes a plurality of permanent magnets evenly spaced about an outside perimeter of said rotor.