Method and apparatus for producing winding slot insulators and inserting same into the stator core of an electromechanical machine

Abstract

Insulating slot liners for insertion into stator core winding slots are formed from a narrow-width reel of insulating material. The width of the material is determined by the inner circumferential surface of the winding slot that must be insulated, instead of being based on the axial length of the stator core as has been the practice in the past. As a result, slot liners may be easily produced for stator cores of different axial lengths by simply adjusting the length of material cut from the reel. Preferably, the cutting mechanism used to cut the length of material is adapted to form a pair of opposed cuffs when the material is cut. An insulator blank formed in this manner is pushed into a die, thereby forming a U-shaped slot liner. A transfer mechanism functions to move the slot liner into a respective winding slot. The slot liner preferably passes through a reduced diameter guideway defined in a guide element as it is moved into the winding slot. The guide element is adapted to be retracted from its operative position after insertion of the slot liner so that the stator core can be indexed to the next slot position.

What is claimed is:  
     
         1 . A method of forming and inserting a winding slot insulator in a winding slot defined in a stator core, said method comprising steps of: 
 (a) providing an elongate strip of slot insulator material having a predetermined width equivalent to an inner circumferential portion of said winding slot to be insulated;    (b) separating a predetermined length of said slot insulator material from said strip to provide an insulator blank, said predetermined length being based on an axial length of said stator core;    (c) forming said insulator blank into a U-shaped slot insulator; and    (d) inserting said U-shaped slot insulator into a selected winding slot of said stator core.    
     
     
         2 . A method as set forth in  claim 1 , further comprising the step of forming cuffs at both axial ends of said insulator blank prior to step (c).  
     
     
         3 . A method as set forth in  claim 2 , wherein said cuffs are formed at a trailing end of said insulator blank and a leading end of said elongate strip.  
     
     
         4 . A method as set forth in  claim 3 , wherein said cuffs are produced by vertically-moving cuff pushers operating adjacent to a cutting blade.  
     
     
         5 . A method as set forth in  claim 1 , wherein said U-shaped slot insulator is inserted axially into said selected winding slot through a reduced-dimension guide element presenting a reduced dimension guideway.  
     
     
         6 . A method as set forth in  claim 5 , further comprising the step of moving the guide element to a location adjacent to said selected winding slot prior to insertion of said U-shaped slot insulator.  
     
     
         7 . Apparatus as set forth in  claim 1 , wherein said elongate strip of insulator material is formed as a reel.  
     
     
         8 . Apparatus for forming and inserting a winding slot insulator in a winding slot defined in a stator core, said apparatus comprising: 
 a reel support adapted to maintain a reel of slot insulator material having a predetermined width;    a feed mechanism operative to deliver a quantity of said slot insulator material from said reel to a cutting station;    a cutting mechanism located at said cutting station, said cutting mechanism operative to cut through said slot insulator material to provide an insulator blank having cuffs at respective ends thereof;    a die mechanism in which said insulator blank is received, said die mechanism being operative to form said insulator blank into a U-shaped slot insulator; and    a transfer mechanism operative to insert said U-shaped slot insulator into said winding slot.    
     
     
         9 . Apparatus as set forth in  claim 8 , wherein said cutting mechanism includes a cutting blade having first and second cuff pushers located on each side thereof, said cuff pushers being operative to form a respective cuff on a trailing end of said insulator blank and a leading end of said quantity of insulator material.  
     
     
         10 . Apparatus as set forth in  claim 9 , wherein said cutting blade and said cuff pushers are operative to move together from opposite sides of said insulator material.  
     
     
         11 . Apparatus as set forth in  claim 8 , further comprising a retractable guide element movable to an operative position adjacent to the winding slot, said guide element presenting a reduced dimension guideway through which said U-shaped slot insulator is inserted.  
     
     
         12 . Apparatus as set forth in  claim 11 , wherein said guideway of said retractable guide element is formed by plural components that converge together as said guide element is moved into said operative position.  
     
     
         13 . Apparatus as set forth in  claim 8 , wherein said die mechanism is situated in longitudinal alignment with said cutting station for receipt of said insulator blank therein.  
     
     
         14 . Apparatus as set forth in  claim 9 , wherein said die mechanism is operative to move laterally from a first position adjacent said cutting station to a second position aligned with said winding slot.  
     
     
         15 . Apparatus for forming and inserting a winding slot insulator in a winding slot defined in a stator core, said apparatus comprising: 
 a feed mechanism operative to deliver a quantity of slot insulator material to a cutting station;    a cutting mechanism located at said cutting station, said cutting mechanism operative to cut through said slot insulator material to provide an insulator blank having a predetermined length;    a die mechanism in which said insulator blank is received, said die mechanism being operative to form said insulator blank into a U-shaped slot insulator;    a transfer mechanism operative to insert said U-shaped slot insulator into said winding slot; and    a retractable guide element movable to an operative position adjacent to the winding slot, said guide element presenting a reduced dimension guideway through which said U-shaped slot insulator is inserted.    
     
     
         16 . Apparatus as set forth in  claim 15 , wherein said guideway of said retractable guide element is formed by plural components that converge together as said guide element is moved into said operative position.  
     
     
         17 . Apparatus for forming a cuffed insulator blank from an elongate strip of insulator material, said apparatus comprising: 
 a reel support adapted to maintain a reel of slot insulator material having a predetermined width;    a feed mechanism operative to deliver a quantity of said slot insulator material from said reel to a cutting station; and    a cutting mechanism located at said cutting station, said cutting mechanism operative to cut through said slot insulator material to provide an insulator blank of predetermined length, said cutting mechanism being further operative to form a respective cuff on a trailing end of said insulator blank and a leading end of said quantity of insulator material.    
     
     
         18 . Apparatus as set forth in  claim 17 , wherein said cutting mechanism includes a cutting blade having first and second cuff pushers located on each side thereof.  
     
     
         19 . Apparatus as set forth in  claim 18 , wherein said cutting blade and said cuff pushers are operative to move together from opposite sides of said insulator material.  
     
     
         20 . Apparatus for inserting a winding slot insulator in a winding slot defined in a stator core, said apparatus comprising: 
 a cutting mechanism operative to cut an insulator blank from a longitudinal strip of slot insulator material;    a die mechanism in which said insulator blank is received, said die mechanism being operative to form said insulator blank into a U-shaped slot insulator;    a transfer mechanism operative to insert said U-shaped slot insulator into said winding slot; and    a retractable guide element movable to an operative position adjacent to the winding slot, said guide element presenting a reduced dimension guideway through which said U-shaped slot insulator is inserted.    
     
     
         21 . Apparatus as set forth in  claim 20 , wherein said guideway of said retractable guide element is formed by plural components that converge together as said guide element is moved into said operative position.  
     
     
         22 . Apparatus as set forth in  claim 21 , wherein said die mechanism is operative to move laterally from a first position at which said insulator blank is received to a second position aligned with said winding slot.