Composite motor stator

Abstract

A hollow stator for a Moineau-style motor is constructed from a composite material such as fiberglass or graphite. A series of lobes arranged along its inner surface corresponds to the external lobes of a rotor inserted in the stator, and enables use of a constant width elastomer layer between the stator and the rotor. The composite stator includes a pair of box socket interface members at its ends to enable the stator to be attached to other components such as pipeline sections.

1 . A stator configured for use in a motor comprising: 
 a hollow pipe, said pipe having a length, an inner profile and an outer profile, said pipe being made from a plurality of fibers adhered together by resin;    wherein said inner profile of said pipe has a plurality of lobes, said lobes of inner profile being disposed in a helical arrangement along said length of said pipe.    
   
   
       2 . The stator of  claim 1 , further comprising: 
 a first end for said pipe,    a metal box connector attached to said first end of said pipe.    
   
   
       3 . The stator of  claim 1 , 
 said plurality of fibers adhered together by resin being a fiberglass composite.    
   
   
       4 . The stator of  claim 1 , 
 said plurality of fibers adhered together by resin being a graphite composite.    
   
   
       5 . The stator of  claim 1 , further comprising: 
 a layer of elastomer applied to said inner profile.    
   
   
       6 . The stator of  claim 5 , said layer of elastomer being of a constant thickness and extending the length of said plurality of lobes.  
   
   
       7 . The stator of  claim 1 , further comprising: 
 first and second ends for said pipe,    a first metal box connector attached to said first end; and    a second metal box connector attached to said second end.    
   
   
       8 . The stator of  claim 1 , said outer profile being circular.  
   
   
       9 . A motor, comprising: 
 A stator having a length, an inner profile and an outer profile, said stator being made from a plurality of fibers adhered together by resin, said inner profile of said stator has a plurality of lobes, said lobes of inner profile being disposed in a helical arrangement along said length of said stator;    A rotor residing inside said stator, said rotor having an outer surface defining a plurality of lobes but one fewer than defined by said stator, said lobes of said rotor being disposed in a helical arrangement along said length of said rotor.    
   
   
       10 . The motor of  claim 9 , said rotor having a first stiffness and said stator having a second stiffness, said first stiffness and said second stiffness differing by at most ten percent.  
   
   
       11 . The motor of  claim 9 , said rotor having a first stiffness and said stator having a second stiffness, said first stiffness and said second stiffness being the same.  
   
   
       12 . The motor of  claim 9 , further comprising: 
 a first end for said stator,    a metal box connector attached to said first end of said stator.    
   
   
       13 . The motor of  claim 9 , 
 said plurality of fibers adhered together by resin being a fiberglass composite.    
   
   
       14 . The motor of  claim 9 , 
 said plurality of fibers adhered together by resin being a graphite composite.    
   
   
       15 . The motor of  claim 9 , further comprising: 
 a layer of elastomer applied to said inner profile.    
   
   
       16 . The motor of  claim 15 , said layer of elastomer being of a constant thickness and extending the length of said plurality of lobes.  
   
   
       17 . The motor of  claim 9 , further comprising: 
 first and second ends for said stator,    a first metal box connector attached to said first end; and    a second metal box connector attached to said second end.    
   
   
       18 . The motor of  claim 9 , said stator having a circular outer profile.  
   
   
       19 . A method for joining a hollow, metal box housing to a composite stator tube, comprising: 
 filling a relieved area on an interior surface of said metal box housing with epoxy;    inserting an end of said composite stator tube into said metal box housing until said end of said stator tube is adjacent said relieved area;    inserting a wedge ring into said metal box housing, said wedge ring abutting said end of said stator tube upon the insertion of both the stator and the wedge ring into said metal box housing such that said end of said stator is forced toward said relieved area; and    affixing said stator tube to said metal box housing by hardening of said epoxy.    
   
   
       20 . The method of  claim 19 , said composite stator tube being a graphite composite.  
   
   
       21 . The method of  claim 19 , said composite stator tube being a fiberglass composite.  
   
   
       22 . The method of  claim 19 , said wedge ring being rotatably inserted into said metal box housing via a threaded engagement between threads on the exterior of said wedge ring and threads on the interior of said metal box housing.  
   
   
       23 . The method of  claim 19 , an interior end of said box housing being threaded.