Common lamination component for accommodating multiple conductor geometries in an electric machine

Abstract

Rectangular conductor wires ( 38 ) are often used in alternator applications requiring a high slot fill to maximize output and efficiency. However for lower output and efficiency applications, round conductor ( 40 ) wire may increase cost competiveness in these alternators. A common lamination for a core ( 110 ) alternatively accommodates both rectangular conductor wires ( 38 ) and round conductor wires ( 40 ) for different applications without any other component changes. The lamina has a slot ( 112 ) that aligns round wire ( 40 ) in a single row within the slot and provides a predetermined clearance from the slot opening ( 126 ). A stator core ( 110 ) formed from these laminae has a relatively high slot fill factor when wound with the round wire ( 40 ). The same stator core ( 110 ) can be alternatively wound with square wire ( 38 ) to increase the slot fill factor even higher. The common lamination results in two stator configurations: a high slot fill version (round wire) and a very high slot fill version (square wire).

1 . A stator core for an electric machine, comprising:
 a core body ( 111 ) having a plurality of teeth ( 120 ), adjacent teeth ( 120 ) of the plurality of teeth ( 120 ) defining respective slots ( 112 ) in the core body ( 111 ), each slot ( 112 ) having a slot depth (D C ′) in a respective direction ( 23 ) along which the teeth ( 120 ) extend from the core body ( 111 ) and a slot width (W C ) in a respective direction along which the teeth ( 120 ) are spaced circumferentially from each other,   wherein the core body ( 111 ) has a configuration in which a plurality of elongate wire segments ( 40 ) having a round cross section are arranged in single file within each slot ( 112 ), the round cross section having a diameter (Ø) that approximates the slot width (Wc), and   wherein the slot depth (D C ′) has a range defined by the equation
   ( N *Ø)+0.2≦ D   C ′≦( N+ 1)*Ø
 
   where N equals the number of the second wire segments ( 40 ) in the slot ( 112 ) and Ø equals the diameter of the second wire segments ( 40 ).   
     
     
         2 . The stator core of  claim 1 , wherein:
 the plurality of elongate wire segments are second elongate wire segments, and the configuration in which the plurality of second elongate wire segments are arranged in a single file within each slot ( 111 ) is a second configuration; and   the core body ( 111 ) has an alternative first configuration in which a first plurality of elongate wire segments ( 38 ) having a rectangular cross section are arranged in single file within in each slot ( 112 ), the rectangular cross section having a cross-sectional dimension (W RCS ) that approximates the slot width (Wc), and   the core body ( 111 ) in the first configuration has a first slot fill factor and the core body ( 111 ) in the second configuration has a second slot fill factor, the second slot fill factor within 10 percent of the first slot fill factor.   
     
     
         3 . The stator core of  claim 1 , wherein distal end faces of the plurality of teeth ( 120 ) define a circumferential face ( 16 ) of the core body ( 111 ), and wherein a distal-most segment ( 40   a ) of the second wire segments ( 40 ) has a minimum clearance to the circumferential face ( 16 ). 
     
     
         4 . The stator core of  claim 2 , further comprising a plurality of insulation sleeves ( 121 ) arranged respectively in each of the slots ( 112 ), the insulation sleeves having a substantially uniform thickness (t), wherein the round cross section having a diameter (Ø) that approximates the slot width (W C ) more specifically approximates the slot width (W C ) minus twice the thickness (t) of the insulation sleeves (W C −2t). 
     
     
         5 . The stator core of  claim 4 , wherein:
 the first wire segments ( 38 ) have a first insulation layer ( 30 ) with a substantially uniform thickness, the cross-sectional dimension (W RCS ) of the first wire segments ( 38 ) including the thickness of the first insulation layer ( 30 ), and   the second wire segments ( 40 ) have a second insulation layer ( 130 ) with a substantially uniform thickness, the diameter (Ø) of the second wire segments ( 40 ) including the thickness of the second insulation layer ( 130 ).   
     
     
         6 . The stator core of  claim 5 , wherein each insulation sleeve ( 121 ) defines a sleeve slot ( 132 ) with a sleeve slot width (W S ) in the slot width direction and a sleeve slot depth (D S ′) in the slot depth direction ( 23 ), wherein the sleeve slot width (W S ) is approximately equal to the slot width (W C ) minus twice the thickness (t) of the insulation sleeves (W C −2t), and wherein the sleeve slot depth (D S ′) has a range defined by the equation
   ( N *Ø)+0.2≦ D   S ′≦( N+ 1)*Ø.
 
 
     
     
         7 . The stator core of  claim 2 , wherein the number of first wire segments ( 38 ) in each of the slots ( 112 ) is eight in the first configuration of the core body ( 111 ), and wherein the number of second wire segments ( 40 ) in each of the slots ( 112 ) is six in the second configuration of the core body ( 111 ). 
     
     
         8 . The stator core of  claim 7 , wherein the first slot fill factor is 0.62 and the second slot fill factor is 0.56. 
     
     
         9 . The stator core of  claim 3 , wherein the minimum clearance of the distal-most segment ( 40   a ) of the second wire segments ( 40 ) to the circumferential face ( 16 ) is 0.5 mm. 
     
     
         10 . Two stator core assemblies for respective electric machines, comprising:
 a first stator core ( 110   1 ) and a second stator core ( 110   2 ) that is identical to the first stator core ( 110   1 ), each stator core having a plurality of teeth ( 120 ) with adjacent teeth ( 120 ) of the plurality of teeth ( 120 ) defining respective slots ( 112 ),   wherein the first stator core ( 110   1 ) has a first plurality of elongate wire segments ( 38 ) arranged in single file within in each slot ( 112 ), the first wire segments having a rectangular cross section, and   wherein the second stator core ( 110   2 ) has a second plurality of elongate wire segments ( 40 ) arranged in single file within each slot ( 112 ), the second wire segments having a round cross section.   
     
     
         11 . The stator core assemblies of  claim 10 , wherein each slot ( 112 ) has a slot depth (D C ′) in a respective direction ( 23 ) along which the teeth ( 120 ) extend from the respective stator cores, the slot depth (D C ′) having a range defined by the equation
   ( N *Ø)+0.2≦ D   C ′≦( N+ 1)*Ø
 
 where N equals the number of the second wire segments ( 40 ) in the slot ( 112 ) and Ø equals the diameter of the second wire segments ( 40 ). 
 
     
     
         12 . The stator core assemblies of  claim 10 , wherein:
 each slot  112  has a slot width (W C ) in a respective direction along which the teeth ( 120 ) are spaced circumferentially from each other,   the rectangular cross section of the first wire segments of the first stator core has a cross-sectional dimension (W RCS ) that approximates the slot width (Wc), and   the round cross section of the second wire segments of the second stator core has a diameter (Ø) that approximates the slot width (Wc).   
     
     
         13 . The stator core assemblies of  claim 10 , wherein the slot width (W C ) is configured to allow unrestricted radial insertion of the first wire segments ( 38 ) in the first stator core ( 110   1 ) and the second wire segments ( 40 ) in the second stator core ( 110   2 ). 
     
     
         14 . The stator core assemblies of  claim 10 , wherein each tooth of the plurality of teeth ( 120 ) has a distal end spaced from a bottom of the slot ( 112 ), and wherein a distal-most segment ( 40   a ) of the second wire segments ( 40 ) in the second stator core ( 110   2 ) has a predetermined minimum clearance to the distal ends of the adjacent teeth ( 120 ). 
     
     
         15 . (canceled) 
     
     
         16 . A lamina for forming a core of an electric machine, comprising:
 a lamina body ( 111 ) with a disk-like shape, the lamina body ( 111 ) having a plurality of teeth ( 120 ) with adjacent teeth ( 120 ) of the plurality of teeth ( 120 ) defining respective slots ( 112 ), each slot ( 112 ) having a slot depth (IV) in a respective direction ( 23 ) along which the teeth ( 120 ) extend from the lamina body ( 111 ) and a slot width (W C ) in a respective direction along which the teeth ( 120 ) are spaced circumferentially from each other,   wherein the lamina body ( 111 ) is configured to accommodate a first plurality of elongate wire segments ( 38 ) having a rectangular cross section, the rectangular cross section having a cross-sectional dimension (W RCS ) that approximates the slot width (W C ) such that the slot ( 112 ) aligns the first wire segments ( 38 ) in single file within the slot ( 112 ),   wherein the lamina body ( 111 ) is configured to alternatively accommodate a second plurality of elongate wire segments ( 40 ) having a round cross section, the round cross section having a diameter (Ø) that approximates the slot width (W C ) such that the slot ( 112 ) aligns the second wire segments ( 40 ) in single file within the slot ( 112 ), and   wherein the slot depth (D C ′) has a range defined by the equation
   ( N *Ø)+0.2≦ D   C ′≦( N+ 1)*Ø
 
   where N equals the number of the second wire segments ( 40 ) in the slot ( 112 ) and Ø equals the diameter (Ø) of the second wire segments ( 40 ).