Patent Publication Number: US-2016241093-A1

Title: Lubricant channel on a stator winding support

Description:
BACKGROUND 
     The present disclosure relates to a generator and, in particular, to a stator for a generator. 
     Typically, a generator includes a rotor having a plurality of coils (made up of electrically conductive wires) wrapped around elongated poles on a rotor core. The rotor is driven to rotate by a source of rotation: a prime mover such as a turbine rotor. The generator rotor rotates in proximity to a stator, and the rotation of the rotor, which is an electromagnet due to electricity running through the coils, includes voltage in the stator. The voltage in the stator can be applied to external electrical components, providing electrical power to those components. The electricity running through the coils is supplied by an exciter, which is a separate rotor-stator component also driven by the source of rotation. The exciter stator includes a plurality of windings (made up of electrically conductive wires), much like the generator rotor coils, that are energized to create alternating North-South magnetic fields to induce a voltage in the exciter rotor as the rotor rotates. The voltage is rectified by a diode pack and then transferred to the main rotor. The exciter stator windings are wrapped around winding supports on a stationary exciter stator core, which is radially outward from the exciter rotor. The winding supports provide insulation against the stator core and support to hold the windings in place. Because the windings on the winding supports convey electricity, the windings may experience elevated temperatures. Therefore, it is advantageous to have a system that cools the exciter stator windings. 
     SUMMARY 
     A stator for a generator includes a core having a back iron that is annular in shape and poles that extend inward from the back iron, a hoop having an annular shape that is radially inward from the back iron, and a plurality of winding supports surrounding the poles. Each winding support includes a tooth extending radially inward from the hoop and surrounding a corresponding pole with the tooth having a first end adjacent to the hoop and a second end radially inward from the first end and a first channel on a first axial side of the tooth extending from the second end to the first end. The stator also includes a plurality of windings with each winding wrapped around a corresponding tooth so that each winding is spaced from the tooth at the first channel. 
     A method of cooling a plurality of windings on a stator includes providing a core with an annular back iron and inward extending poles and a hoop with a plurality of radially inward extending winding supports surrounding the poles. Each winding support having a radially inward extending tooth encasing a corresponding pole with the tooth having a first channel on a first axial side and each winding support having a corresponding winding made up of an electrically conductive wire wrapped around the tooth. The method also includes introducing a cooling lubricant into the first channel and flowing the cooling lubricant adjacent to an inner layer of the electrically conductive wire of each winding through the first channel. 
     The present summary is provided only by way of example and not limitation. Other aspects of the present disclosure will be appreciated in view of the entirety of the present disclosure, including the entire text, claims, and accompanying figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic sectional view of a generator. 
         FIG. 2A  is a perspective view of an exciter stator with windings. 
         FIG. 2B  is a perspective view of the exciter stator without windings. 
         FIG. 3  is a perspective view of one winding support of the exciter stator. 
         FIG. 4  is a cross-section partial view of one winding support of the exciter stator. 
     
    
    
     While the above-identified figures set forth embodiments of the present disclosure, other embodiments are also contemplated, as noted in the discussion. In all cases, this disclosure presents the invention by way of representation and not limitation. It should be understood that numerous other modifications and embodiments can be devised by those skilled in the art, which fall within the scope and spirit of the principles of the invention. The figures may not be drawn to scale, and applications and embodiments of the present invention may include features and components not specifically shown in the drawings. 
     DETAILED DESCRIPTION 
     A stator for a generator is disclosed herein that includes at least one channel for cooling lubricant on each of a plurality of winding supports. Electrically conductive wire windings, which can experience elevated temperatures during operation of the generator, are wrapped around each of the plurality of winding supports, which insulate the windings from a stator core (a back iron and inwardly extending poles with pole tips). The channel allows easier access to inner layers of the electrically conductive wire windings so oil or another cooling lubricant, which is provided by lubricant jets on a radially inward rotor, can flow to inner layers of the wires and between individual wires of the windings to help prevent damage to the windings due to elevated temperatures. 
       FIG. 1  is a schematic sectional view of a generator. Generator  20  is driven by prime mover T, which can be, for example, a gas turbine engine. Generator  20  produces electrical energy when being driven by prime mover T. Generator  20  generally includes dynamoelectric portion  22 , positive displacement pump  24 , and gearbox  26 , all of which are contained within housing assembly  28 . Although a variable frequency generator (VFG) is illustrated in the disclosed embodiment, it should be understood that other generator systems, such as a variable frequency starter generator (VFSG) and integrated drive generator (IDG), are also within the scope of the invention. 
     Dynamoelectric portion  22  in the disclosed, non-limiting embodiment is a three-phase machine that includes permanent magnet generator  30 , exciter  32 , and main generator  34  (the three phases) mounted along rotor shaft  36 , which rotates about axis of rotation A. Permanent magnet generator  30  includes rotor assembly  30 A and stator assembly  30 B, exciter  32  includes rotor assembly (exciter rotor)  32 A and stator assembly (exciter stator)  32 B, and main generator  34  includes rotor assembly  34 A and stator assembly  34 B. Stator assemblies  30 B,  32 B, and  34 B are installed in housing assembly  28  and do not rotate while rotor assemblies  30 A,  32 A, and  34 A are installed on rotor shaft  36  and rotate in unison. Housing assembly  28  can be closed at one end by drive-end cover assembly  28 A through which rotor shaft  36  extends and at the other end by non-drive-end cover assembly  28 B through which rotor shaft  36  does not extend. 
     Permanent magnet generator  30 , with rotor assembly  30 A and stator assembly  30 B, supplies power for generator excitation, as well as power for other components of an electrical system. Exciter  32 , with exciter rotor  32 A and exciter stator  32 B, receives field excitation from permanent magnet generator  30  through the generator power control unit (GPCU). The output of exciter  32  is supplied to rotor mounted diode pack  37 . Diode pack  37  can be divided into six diodes to provide a three-phase full wave bridge rectification. Diode pack  37  then supplies main generator  34  with electricity to produce a magnetic field. Main generator  34 , with rotor assembly  34 A and stator assembly  34 B, outputs power to supply external electrical energy needs. 
       FIG. 2A  is a perspective view of exciter stator  32 B with windings,  FIG. 2B  is a perspective view of exciter stator  32 B without windings, and  FIG. 3  is an enlarged view of one winding support of exciter stator  32 B. Exciter stator  32 B includes core  38  (the outer annular ring of core  38  is the back iron while the inwardly extending components are the poles (seen in  FIG. 4 ) having pole tips  56 ), hoop  39 , slots  40 , windings  41 , and winding supports  42 . Each winding support  42  includes tooth  44 , first tooth tip  46 A, second tooth tip  46 B, first post  48 A, second post  48 B, third post  48 C, fourth post  48 D, first channel  50 , and second channel  52 . Hoop  39  includes fifth post  58 A, sixth post  58 B, seventh post  58 C, eighth post  58 D, wire inlet  60 A, and wire outlet  60 B. Hoop  39  and winding supports  42  can be split into top hoop/support  39 A and bottom hoop/support  39 B, as illustrated, or can be monolithically formed in further embodiments. 
     Exciter stator  32 B is a stationary component of generator  20  that is radially outward from exciter rotor  32 A. Exciter stator  32 B is provided with DC voltage that excites each winding  41  wrapped around each of the plurality of winding supports  42 . Each winding  41  can be a coil of a wire wrapped around each winding support  42  in alternating directions so that, when the wire is excited with DC power, the plurality of windings  41  produce an alternating North-South magnetic configuration. When exciter rotor  32 A rotates within exciter stator  32 B, the alternating North-South magnetic configuration of windings  41  of exciter stator  32 B induces AC voltage in electrically conductive coils on exciter rotor  32 A, which is then outputted to diode pack  37  to provide electricity to main generator  34 . 
     Core  38  is the main structural component of exciter stator  32 B and includes the back iron, which is the outer annular ring shown in  FIGS. 2A and 2B , and the poles (shown in  FIG. 4  as poles  64 ), which are the inwardly extending components having pole tips  56  at a radially inner end. Core  38  can be made from a number of pieces or can be one integral and monolithic piece. The back iron of core  38  can have grooves, notches, holes, projections, or other configurations to which other components of exciter stator  32 B can be inserted and/or attached. Core  38  can be made from metal, such as electrical steel, or another material. Additionally, core  38  can be laminated stacks that are bonded, interlocked, or welded together. 
     The insulating components of exciter stator  32 B include hoop  39  and the plurality of winding supports  42 . Hoop  39  is annular in shape and radially within the back iron of core  38 . Hoop  39  insulates windings  41  from the back iron of core  38  and includes a number of openings through which the poles of core  38  extend inward. Hoop  39  can have grooves, notches, holes, projections, or other configurations that allow hoop  39  to be held adjacent to core  38 . Hoop  39  can be bonded to the back iron of core  38  by adhesives or another fastener, and can be made from a variety of materials, including electrically insulating materials such as thermoplastics or other materials that are able to be additively manufactured or molded. Hoop  39  can be made from a number of pieces fastened together to form the annular shape with openings or can be one integral and monolithic piece constructed through molding, additive manufacturing, or another process. Additionally, hoop  39  and winding supports  42  can be made from the same material and can be integral and monolithic. As shown in  FIGS. 2A, 2B, and 3 , hoop  39  can also be constructed to be two generally annular pieces that, along with winding supports  42 , mate at an axial joint to encase the poles of core  38 . However, the material of hoop  39  should be able to provide an electrical barrier between the electrically conductive windings  41  and core  38  while also being able to handle the structural requirements of exciter stator  32 B and winding supports  42 . 
     Each winding support  42  extends radially inward from hoop  39  and has a number of components (discussed below) that function to hold windings  41  in place and insulate windings  41  from other components of exciter stator  32 B, including the poles of core  38  (shown in  FIG. 4  as pole  64 ), which are encased by each winding support  42 . Each winding support  42  can be made from a number of pieces or can be one integral and monolithic piece with hoop  39  such that hoop  39  and the plurality of winding supports  42  are constructed from the same material so as to be one piece. As shown in  FIGS. 2A, 2B, and 3 , hoop  39  and the plurality of winding supports  42  can also be constructed to be two generally annular pieces (both hoop  39  and winding supports  42  are split axially to form top hoop/support  39 A and bottom hoop/support  39 B) that are secured together to form the hoop-winding support configuration. As mentioned above, each winding support  42 , or hoop  39  and the plurality of winding supports  42  together, can be made from a variety of materials and constructed through molding, additive manufacturing, or another process. 
     As mentioned above, the poles of core  39  extending from the back iron are encased by corresponding winding supports  42  such that winding supports  42  insulate windings  41  from core  39  and other components of exciter stator  32 B. While exciter stator  32 B of  FIGS. 2A and 2B  shows a configuration that includes ten poles and ten corresponding winding supports  42 , other stators can have any number of poles and winding supports  42 , including configurations that have two, four, six, eight, or twelve poles and winding supports  42 . Although the disclosed embodiment shows each winding support  42  having a similar configuration, each winding support  42  can have a differing configuration than other winding supports  42  within exciter stator  32 B. 
     Tooth  44  of winding support  42  extends radially inward from hoop  39  with one end adjacent hoop  39  and the other forming a radially innermost end of tooth  44  (and winding support  42 ). Tooth  44  encases a corresponding pole of core  39  (as seen in  FIG. 4 ). Tooth  44  of the disclosed embodiment is shown to have a generally rectangular cross-section extending radially inward (a partial cross-section is shown in  FIG. 4 ), but can have another cross-section, such as circular, crowned, or oblong. However, winding support  42  should have a width (distance in the circumferential direction) that is sufficient to fully insulate windings  41  and allow for first channel  50  and second channel  52  to be present on tooth  44  (discussed in greater detail below). Additionally, tooth  44  can be bonded or fastened to the corresponding poles of core  39  a variety of ways, including adhesive, welds, or other fasteners. Tooth  44  should be long enough radially to completely encase the pole of core  39  and to allow windings  41  to wrap around tooth  44  a sufficient number of times (to form a coil of electrically conductive wires) but not so long as to physically interfere with the rotation of exciter rotor  34 A radially within the innermost end of tooth  44  (and winding support  42 ). 
     First tooth tip  46 A and second tooth tip  46 B extend circumferentially from the radially innermost end of tooth  44  in opposite directions. The radially inner surface of first tooth tip  46 A and second tooth tip  46 B can form a segmented circular shape such that the plurality of first tooth tips  46 A and second tooth tips  46 B on each of the plurality of winding supports  42  form a generally cylindrical shape (with spaces between first tooth tip  46 A of one winding support  42  and second tooth tip  46 B of an adjacent winding support  42 ). A radially outer surface of first tooth tip  46 A and second tooth tip  46 B can be angled towards tooth  44 , as shown in  FIG. 2B , or have another configuration, such as a consistent radial width, but first tooth tip  46 A and second tooth tip  46 B should be configured so as to hold winding  41  wrapped around tooth  44  in place to help prevent movement. First tooth tip  46 A and second tooth tip  46 B are shown as extending axially along the total length of the innermost end of tooth  44 , but can also be shorter or longer in axial length than tooth  44 . 
     First post  48 A extends axially outward from first tooth tip  46 A in a first axial direction (towards the top of the illustration in  FIGS. 2A, 2B, and 3 ), second post  48 B extends axially outward from second tooth tip  46 B in the first axial direction, third post  48 C extends axially outward from first tooth tip  46 A in a second axial direction (towards the bottom of the illustration in  FIGS. 2A, 2B, and 3 ), and fourth post  48 D extends axially outward from second tooth tip  46 B in the second axial direction. First post  48 A through fourth post  48 D each have a radially inner surface that can follow the curve of the radially inner surface of tooth  44 , first tooth tip  46 A, and second tooth tip  46 B, and each can have a radially outer surface that is adjacent to windings  41  and follows the configuration of the radially outer surface of first tooth tip  46 A and second tooth tip  46 B. Together, first post  48 A through fourth post  48 D provide support to winding  41  to help prevent winding  41  from moving radially inward and ensure that winding  41  does not come unwrapped/unfurled. While the disclosed embodiment shows each of the plurality of winding supports  42  having first post  48 A through fourth post  48 D, other designs could include configurations in which only a select number of winding supports  42  have one or all of first post  48 A through fourth post  48 D. 
     First channel  50  is located on a first axial side of tooth  44  (the top side of the illustration in  FIGS. 2A, 2B, and 3  corresponding to the first axial direction), while second channel  52  is located on a second axial side of tooth  44  (the bottom side of the illustration in  FIGS. 2A, 2B, and 3  corresponding to the second axial direction). First channel  50  and second channel  52  are each a radial groove (having an axial depth) in tooth  44  that allows lubricant, such as oil, to access inner layers of the electrically conductive wire of winding  41  by providing a space between the surface of tooth  44  and winding  41  (more easily seen in  FIG. 4 ). While the disclosed embodiment shows first channel  50  and second channel  52  each as a singular groove of a consistent depth, other configurations are possible, including multiple grooves and/or a groove that has a varied depth or shape as it extends radially along tooth  44 . As will be discussed further in regards to  FIG. 4 , the depth of first channel  50  and second channel  52  should be designed to allow a sufficient amount of lubricant to access the inner layers or winding  41  to help prevent overheating and damage to winding  41 . Additionally, the depth and configuration of first channel  50  can be different than that of second channel  52 , depending on design considerations. 
     First channel  50  and second channel  52  are generally located near of the circumferential center of the tooth  44  on the first axial side and second axial side, respectively. First channel  50  can be arranged such that first post  48 A, second post  48 B, and first channel  50  form a generally U shape at the radially innermost end of winding support  42  on the first axial side. Second channel  52  can be arranged such that third post  48 C, fourth post  48 D, and second channel  52  form a generally U shape at the radially innermost end of winding support  42  on the second axial side. The width (distance in the circumferential direction) of first channel  50  and/or second channel  52  can also be wider than a distance between first post  48 A and second post  48 B and the distance between third post  48 C and fourth post  48 D, respectively. 
     Slot  40  is the space between adjacent winding supports  42  (the space between adjacent teeth  44 , first tooth tips  46 A, and second tooth tips  46 B) and allows room for adjacent windings  41  on each winding support  42  to be wrapped and insulated from one another to form alternating North-South winding support  42  configurations. Depending on the number of poles and winding supports  42  of exciter stator  32 B, slot  40  may be circumferentially wide or narrow. 
     Pole tip  56  is radially inward from winding supports  42  and at an innermost end of tooth  44  (and the radially inner surface of first tooth tip  46 A and second tooth tip  46 B). Pole tips  56  are part of core  38  such that the back iron, poles, and pole tips  56  of core  38  can be integral and monolithic. 
     Fifth post  58 A extends axially outward from hoop  39  near each tooth  44  in the first axial direction (towards the top of the illustration in  FIGS. 2A, 2B, and 3 ), sixth post  58 B of extends axially outward from hoop  39  near each tooth  44  in the first axial direction, seventh post  58 C extends axially outward from hoop  39  near each tooth  44  in the second axial direction (towards the bottom of the illustration in  FIGS. 2A, 2B, and 3 ), and eighth post  58 D extends axially outward from hoop  39  near each tooth  44  in the second axial direction. Fifth post  58 A through eighth post  58 D are similar to first post  48 A through fourth post  48 D with fifth post  58 A being radially outward from first post  48 A, sixth post  58 B being radially outward from second post  48 B, seventh post  58 C being radially outward from third post  48 C, and eighth post  58 D being radially outward from fourth post  48 D. Together, fifth post  58 A through eighth post  58 D provide support to winding  41  to help prevent winding  41  from moving radially outward and ensure that winding  41  does not come unwrapped/unfurled. Fifth post  58 A through eighth post  58 D can have the same shape and size as first post  48 A through fourth post  48 D or can have a different configuration, such as a different spacing between fifth post  58 A and sixth post  58 B and between seventh post  58 C and eighth post  58 D, respectively. There can also be a configuration in which fifth post  58 A and sixth post  58 B are attached (so that there is no space between them) and/or seventh post  58 C and eighth post  58 D are attached. While the disclosed embodiment shows fifth post  58 A through eighth post  58 D as part of hoop  39 , fifth post  58 A through eighth post  58 D can also be on winding support  42 . 
     Wire inlet  60 A and wire outlet  60 B are holes extending through fifth post  58 A, sixth post  58 B, seventh post  58 C, and/or eighth post  58 D and allow the electrically conductive wire that makes up windings  41  to access the plurality of winding supports  42 . As shown in  FIGS. 2A and 2B , wire inlet  60 A and wire outlet  60 B are adjacent to one another and located on an extension between sixth post  58 B adjacent one tooth  44  and fifth post  58 A adjacent another tooth  44 . Even though wire inlet  60 A and wire outlet  60 B are shown adjacent one another in  FIGS. 2A and 2B , exciter stator  32 B could have multiple wire inlets  60 A and wire outlets  60 B and/or a configuration that does not have wire inlet  60 A adjacent to wire outlet  60 B. 
     Each winding  41  is an electrically conductive wire wrapped in a coil around a corresponding tooth  44  of each winding support  42 . The electrically conductive wire forming winding  41  is wrapped around tooth  44  many times with the number of wraps depending on the strength of the magnetic field needed to be induced, the space available for winding  41 , and the length of the electrically conductive wire. In the disclosed embodiment, the electrically conductive wire enters exciter stator  32 B through wire inlet  60 A and wraps around one winding  41 . After winding  41  is sufficiently wrapped, the electrically conductive wire is then strung to an adjacent winding  41  and is wrapped in an opposite direction than the previous winding  41 . The direction of wrapping of each winding  41  continues so that adjacent windings  41  are wrapped in opposite directions. This wrapping continues until all windings  41  have been wrapped and the electrically conductive wire exits exciter stator  32 B through wire outlet  60 B. Adjacent windings  41  are wrapped in opposite directions so that when electricity is provided to the electrically conductive wire, adjacent windings  41  produce opposite magnetic fields (creating alternating North-South magnetic configurations). Other configurations of exciter stator  32 B can include multiple electrically conductive wires that wrap one or a few windings  41  (and enter and exit through multiple wire inlets  60 A and wire outlets  60 B, respectively). 
     As mentioned above, windings  41  can have an elevated temperature during operation of exciter stator  32 B due to electricity running through the electrically conductive wire of windings  41 . If the temperature of windings  41  becomes too elevated, windings  41  can become damaged. To help prevent damage, a cooling lubricant, such as oil, is provided to windings  41  from lubricant jets on exciter rotor  32 A radially within exciter stator  32 B. The lubricant jets spray lubricant onto exciter stator  32 B. Because first channel  50  and second channel  52  provide a space between winding  41  and tooth  44  into which lubricant can flow (as seen more fully in  FIG. 4 ), first channel  50  and second channel  52  allow lubricant to reach the inner layers of the electrically conductive wire of winding  41  and help keep operational temperatures of windings  41  from becoming elevated, thereby reducing the likelihood that windings  41  will become damaged. 
       FIG. 4  is a cross-sectional view of a portion of hoop  39  and one winding support  42 . Hoop  39  and winding support  42  can be split into top hoop/support  39 A and bottom hoop/support  39 B, which mate together to encase pole  64 . Top hoop/support  39 A includes top tooth portion  44 A, first channel  50  (with depth D 1 ), fifth post  58 A, and sixth post  58 B. Bottom hoop/support  39 B includes bottom tooth portion  44 B, second channel  52  (with depth D 2 ), seventh post  58 C, and eighth post  58 D. Wrapped around top tooth portion  44 A and bottom tooth portion  44 B is winding  41  made up of the electrically conductive wire. 
     First channel  50  and second channel  52  can have a U-shaped configuration, as shown in  FIG. 4 , with a depth D 1  and D 2 , respectively, that is deep enough to allow a sufficient amount of lubricant to access the inner layers of the electrically conductive wires of winding  41  to help prevent overheating. Depth D 1  of first channel  50  and depth D 2  of second channel  52  can vary along a length (in a radially direction; i.e., into/out of the page in  FIG. 4 ) of first channel  50  and second channel  52 , respectively, to provide more or less lubricant to different areas of winding  41 . The disclosed embodiment shows first channel  50  and second channel  52  as having a consistent cross-section that extends along an entire length (in a radially direction) of top tooth portion  44 A and bottom tooth portion  44 B, respectively, but first channel  50  and second channel  52  can have a cross-sectional area that is reduced or enlarged along the radial length of top tooth portion  44 A and bottom tooth portion  44 B, respectively, or different than one another. As mentioned above, first channel  50  and second channel  52  can also be multiple grooves with differing depths. Additionally, first channel  50  and second channel  52  do not have to extend entirely radial in a line, but can also weave or angle circumferentially depending on design considerations. First channel  50  and second channel  52  can have different cross-sectional shapes (other than a U shape), such as a box shape (rectangular cross-section), V shape, W shape, or a channel having a wavy bottom surface. 
     First channel  50  and second channel  52  help prevent winding  41  on each winding support  42  from overheating by allowing lubricant (provided by lubricant jets on exciter stator  32 A) to access the inner layers of the electrically conductive wire of windings  41 . First channel  50  and second channel  52  allow access to inner layers of windings  41  by forming a space between tooth  44  (or top tooth portion  44 A and bottom portion  44 B) and winding  41  into which cooling lubricant can flow. Without first channel  50  and second channel  52 , the cooling lubricant is only able to contact the outer layers of the electrically conductive wire of windings  41 . Because first channel  50  and second channel  52  allow lubricant to more completely access winding  41 , first channel  50  and second channel  52  help prevent damage to each winding  41  on each winding support  42  by reducing the operational temperature of windings  41 . 
     Discussion of Possible Embodiments 
     The following are non-exclusive descriptions of possible embodiments of the present invention. 
     A stator for a generator includes a core having a back iron that is annular in shape and poles that extend inward from the back iron, a hoop having an annular shape that is radially inward from the back iron, and a plurality of winding supports surrounding the poles. Each winding support includes a tooth extending radially inward from the hoop and surrounding a corresponding pole with the tooth having a first end adjacent to the hoop and a second end radially inward from the first end and a first channel on a first axial side of the tooth extending from the second end to the first end. The stator also includes a plurality of windings with each winding wrapped around a corresponding tooth so that each winding is spaced from the tooth at the first channel. 
     The stator of the preceding paragraph can optionally include, additionally and/or alternatively, any one or more of the following features, configurations and/or additional components: 
     A second channel on a second axial side of the tooth extending from the second end to the first end so that each winding is spaced from the tooth at the second channel. 
     A depth of the first channel and a depth of the second channel are configured to allow a sufficient amount of cooling lubricant to access an inner layer of electrically conductive wire that makes up each winding. 
     The hoop and the plurality of windings are constructed from a first component and a second component mated together at an axial joint to encase the poles. 
     The hoop and the plurality of winding supports are constructed using additive manufacturing. 
     The plurality of windings are constructed from one continuous electrically conductive wire. 
     The core includes ten poles and the plurality of winding supports includes ten corresponding winding supports. 
     A first tooth tip extending circumferentially from the second end of the tooth and a second tooth tip extending circumferentially from the second end of the tooth in an opposite direction from the first tooth tip. 
     A first post and a second post extending outward in a first axial direction with the first post extending outward from the first tooth tip and the second post extending outward from the second tooth tip, a third post and a fourth post extending outward in a second axial direction with the third post extending outward from the first tooth tip and the fourth post extending outward from the second tooth tip, a fifth post and a sixth post extending axially outward from the hoop near the first end of the tooth in the first axial direction, and a seventh post and an eighth post extending axially outward from the hoop near the first end of the tooth in the second axial direction. 
     The first post, second post, third post, fourth post, fifth post, sixth post, seventh post, and eighth post are adjacent to each winding and prevent each winding wrapped around a corresponding tooth from movement. 
     The first channel, first post, and second post form a U shape on the first axial side of the tooth. 
     A method of cooling a plurality of windings on a stator includes providing a core with an annular back iron and inward extending poles and a hoop with a plurality of radially inward extending winding supports surrounding the poles. Each winding support having a radially inward extending tooth encasing a corresponding pole with the tooth having a first channel on a first axial side and each winding support having a corresponding winding made up of an electrically conductive wire wrapped around the tooth. The method also includes introducing a cooling lubricant into the first channel and flowing the cooling lubricant adjacent to an inner layer of the electrically conductive wire of each winding through the first channel. 
     The method of the preceding paragraph can optionally include, additionally and/or alternatively, any one or more of the following features, configurations, steps, and/or additional components: 
     Each winding support further includes a second channel on a second axial side into which cooling lubricant can be introduced and flow to the inner layer of the electrically conductive wire of each winding. 
     The step of introducing the cooling lubricant onto an outer layer of the electrically conductive wire of each winding. 
     The cooling lubricant penetrates into an interior of each winding so as to contact multiple layers of the electrically conductive wire. 
     While the invention has been described with reference to an exemplary embodiment(s), it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment(s) disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.