Abstract:
An apparatus for winding wire about a tooth of a core includes an amount of wire, a winding member configured to receive a portion of the amount of wire, and a winding device operatively coupled to the winding member. The winding device being configured to apply a number of wraps of the amount of wire to at least one of a plurality of teeth of the core. The number of wraps including a number of twists that is fewer than the number of wraps.

Description:
BACKGROUND OF THE INVENTION 
     The subject matter disclosed herein relates to the art of electrical machines and, more particularly, to a core winding apparatus and method of winding a core. 
     At present, full stator cores are wound with round wire. The stator core is held stationary and the round wire is fed through a winding needle that is rotated about a stator tooth. Once the stator tooth is wound, the wire is advanced to a subsequent stator tooth. At each tooth, the winding needle not only travels along a circular path but also moves in and out to layer the wire. Upon exiting the winding needle, the wire twists as a result of rotational forces developed while traveling along the circular path. 
     BRIEF DESCRIPTION OF THE INVENTION 
     According to one aspect of the exemplary embodiment, an apparatus for winding wire about a tooth of a core includes an amount of wire, a winding member configured to receive a portion of the amount of wire, and a winding device operatively coupled to the winding member. The winding member being configured to apply a number of wraps of the amount of wire to each of at least one of a plurality of stator teeth of the full stator core. The number of wraps including a number of twists that is fewer than the number of wraps. 
     According to another aspect of the exemplary embodiment, a method of winding a core having a plurality of teeth includes passing a portion of the length of wire through a winding member, and applying a number of wraps of the wire to at least one of the plurality of teeth. The wraps of wire including a number of twists that is fewer than the number of wraps. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       The above, as well as other advantages of the present invention, will become readily apparent to those skilled in the art from the following detailed description when considered in light of the accompanying drawings in which: 
         FIG. 1  is an elevational view of a core being wound by a core winding apparatus in accordance with an exemplary embodiment; 
         FIG. 2  is an elevational view of a rectangular wire in a first orientation being applied without twisting to a tooth of the core of  FIG. 1 ; 
         FIG. 3  is an elevational view of the rectangular wire of  FIG. 2  in a second orientation being applied without twisting to a tooth of the core of  FIG. 1 ; 
         FIG. 4  is an elevational view of the rectangular wire of  FIG. 3  in a third orientation being applied without twisting to a tooth of the core of  FIG. 1 ; and 
         FIG. 5  is an elevational view of the rectangular wire of  FIG. 4  in a third orientation being applied without twisting to a tooth of the core of  FIG. 1 . 
     
    
    
     The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings. 
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference to  FIG. 1 , a core, shown in the form of a full stator core configured to be wound in accordance with an exemplary embodiment is indicated generally at  2 . Stator core  2  includes a main body  4  having an inner diameter  5  provided with a plurality of stator teeth, one of which is indicated at  6 . Stator teeth  6  are arranged in a series of poles, e.g., A 1 -A 4 ; B 1 -B 4 ; and C 1 -C 4  that collectively define electrical phases A, B, and C. Each stator tooth includes a main body  8  having a first substantially planar surface  14 , a second substantially planar surface  15 , a third substantially planar surface  16 , and a fourth substantially planar surface  17  ( FIG. 2 ) so as to define a generally rectangular cross-section. As shown, each stator tooth  6  includes a central axis  20  that passes from a central point of inner diameter  5  radially through each stator tooth  6 . In accordance with an exemplary embodiment, each stator tooth  6  is wound with wire in order to achieve a necessary magnetic field to operate an associated electric machine. 
     In accordance with an exemplary embodiment, stator core  2  is wound using a winding apparatus  30  that is arranged entirely within inner diameter  5 . Winding apparatus  30  includes a winding device  32  provided with a bobbin  34  and a winding member shown in the form of a winding needle  36 . At this point it should be understood that the term bobbin refers to any device that is configured to retain a selected amount of wire. Winding needle  36  includes a first end  38  that extends to a second end  40 . Winding apparatus  30  also includes a winding element  44  that is operatively connected to winding needle  36 . In further accordance with one exemplary embodiment, bobbin  34  is wound with a selected amount of wire  60  that includes a plurality of sides  62 - 65  to define a rectangular cross-section. Winding apparatus  30 , as will be discussed more fully below, is selectively operated in order to wrap each of the plurality of stator teeth  6  with a continuous, untwisted length of wire  60 . More specifically, bobbin  34  is loaded with enough wire  60  to wrap, for example each of poles A 1 -A 4  in a single winding operation. As such, each stator tooth corresponding to poles A 1 -A 4  is wrapped with a continuous piece of untwisted wire in a manner that will be described more fully below. 
     As best shown in  FIGS. 2  though  5 , winding device  32  translates about each of the plurality of stator teeth  6  wrapping wire  60  about planar surfaces  14 - 17 . In addition to the translation of winding device  32 , winding element  44  rotates winding needle  36  causing only one of the plurality of sides  62 - 65  of wire  60  to face each planar surface  14 - 17  of stator tooth  6 . In accordance with another aspect, instead of rotating winding element  44 , winding device  32  is configured to be rotated about a longitudinal axis defined by winding needle  36 . In this manner, stator tooth  6  is wrapped with a number of wraps of wire, with the wire having fewer twists than the total number of wraps. In accordance with one aspect of the invention, the number of twists will be one fewer than the total number of wraps. In accordance with another aspect of the invention, the number of twists will be between one fewer and half the total number of wraps. In accordance with yet another aspect, the number of twists will be fewer than half of the number of wraps. In accordance with still another aspect of the invention, the wire will remain untwisted. In any case, stator tooth  6  will be wrapped with rectangular wire having few twists to enable a tight spacing of wire to minimize an overall form factor of stator core  2 . More specifically, as shown in  FIG. 2 , winding needle  36  positions side  64  of wire  60  facing surface  14  of stator tooth  6 . Winding device  32  then translates about stator tooth  6  positioning winding needle  36  adjacent surface  15 . 
     As best shown in  FIG. 3 , as winding device  32  translates about stator tooth  6 , winding element  44  rotates causing side  64  of wire  60  to face surface  15 . Similarly, as shown in  FIG. 4 , continued translation of winding device  32  results in a corresponding rotation of winding element  44  such that side  64  faces surface  16  of stator tooth  6 . Likewise, as shown in  FIG. 5 , side  64  also faces fourth surface  17  before the wrap is completed. In addition to the translation about stator tooth  6 , winding apparatus  30  oscillates along a substantially linear path defined by axis  20 . In this manner, consecutive adjacent wraps are applied and layered in order to apply predetermined amount of wire to each stator tooth. 
     At this point, it should be understood that an exemplary embodiment provides an apparatus and method of applying a wire, particularly wire having a rectangular cross-section, to a stator tooth. More specifically, the apparatus and method enables a continuous, uninterrupted and untwisted application of wire to a number of stator teeth in order to enhance manufacturing efficiencies and provide a more compact profile on each stator tooth. This is, instead of using round wire, which tends to twist and create bulk, the apparatus of the present invention fits entirely within a full stator core so as to apply a continuous, untwisted length of rectangular wire. In this manner, the stator core will be formed having a smaller profile thereby enabling the construction of even smaller electric machines. In addition to reducing twisting, exemplary embodiments provide a stator core having a minimal number of connections between the stator teeth and a phase lead. Also, while described in connection with a full stator core, it should be understood that the exemplary embodiment can also be employed to wind armatures, segmented cores, flexible cores, rotating cores, stationary cores and the like. In addition, while the winding member is described as a winding needle, various other devices configured to feed wire onto a core tooth can be employed. 
     While embodiments of the invention have been described above, it will be understood that those skilled in the art, both now and in the future, may make various improvements and enhancements which fall within the scope of the claims which follow. These claims should be construed to maintain the proper protection for the invention first described.