Flare tooth stator for an AC generator

Abstract

A stator core extends along a longitudinal axis and includes a yoke, and a plurality of radially-inwardly projecting teeth separated by intervening slots. A radially innermost portion of each tooth initially includes a pair of legs separated by a recess disposed therebetween. The conventional tooth tips are unformed in the first stage, thereby defining an increased-size slot opening for allowing the insertion of stator windings. In a second processing stage, after the core itself has been manufactured and wound with stator windings, the legs are cold-formed in order to form tooth tips, which define a reduced-size slot opening to provide a magnetic flux path and provide a wire retention function. A higher stator slot fill is provided, which allows and enables higher generator efficiencies and output for a given package size.

1 . A stator assembly for a dynamoelectric machine comprising: 
 a stator core having a main longitudinal axis including a yoke and a plurality of radially inwardly-projecting teeth separated by intervening slots wherein a radially innermost portion of at least one of said teeth includes a pair of legs with a recess disposed therebetween.    
     
     
         2 . The stator assembly of  claim 1  wherein said recess has a first radial extent at least one-half that of a second radial extent of the legs.  
     
     
         3 . The stator assembly of  claim 2  wherein the first and second radial extents are approximately equal.  
     
     
         4 . The stator assembly of  claim 1  further comprising one of (i) a slot liner disposed in each slot and (ii) a powder coating disposed in each slot.  
     
     
         5 . The stator assembly of  claim 4  wherein said slots contain a portion of a stator winding.  
     
     
         6 . The stator assembly of  claim 1  wherein each slot has a first slot opening having a first width, said legs being configured to be deformed to produce a second slot opening having a second width that is less than said first width.  
     
     
         7 . The stator assembly of  claim 2  wherein said recess is defined in-part by inner sides of said legs, said inner sides forming a predefined angle ( 22 ) relative to each other that is at least about 45 degrees.  
     
     
         8 . The stator assembly of  claim 7  wherein said predefined angle is at least about 60 degrees.  
     
     
         9 . The stator assembly of  claim 8  wherein said predefined angle is about 66 degrees.  
     
     
         10 . The stator assembly of  claim 6  wherein said first width is greater than about 75 percent of a slot width associated with each slot.  
     
     
         11 . The stator assembly of  claim 10  wherein said first width is greater than about 80 percent of said slot width.  
     
     
         12 . The stator assembly of  claim 11  wherein said first width is about 83 percent of said slot width.  
     
     
         13 . An alternating current (AC) generator comprising a stator assembly having a stator core and a stator winding wherein said stator core extends along a longitudinal axis and includes a yoke, and a plurality of radially-inwardly projecting teeth separated by intervening slots wherein a radially innermost portion of at least one of said teeth includes a pair of legs with a recess disposed therebetween.  
     
     
         14 - 17 . (canceled)