Abstract:
Apparatus and methods for winding dynamo-electric machine components are provided. A dynamo-electric machine component may be provided that includes an annular body portion that is at least partially constructed from an insulating material, a plurality of members extending radially inward from the body portion forming a plurality of slots therebetween, and wire coils that are received within the plurality of slots. Each wire coil may extend from one slot of the plurality of slots to another slot of the plurality of slots. Wire coils may be assembled on such a dynamo-electric machine component using a ram member that positions the wire coils with respect to the component and an annular member that presses a portion of the wire coils against the body portion of the component to maintain the position of the coils.

Description:
[0001]     This application claims the benefit of U.S. provisional patent application Nos. 60/472,707, filed May 21, 2003, 60/484,453, filed Jul. 1, 2003, and 60/487,565, filed Jul. 14, 2003, all of which are hereby incorporated by reference herein in their entireties. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     The present invention relates to improved cores for dynamo-electric machines and to apparatus and methods for their manufacture at production rates of an industrial environment. More particularly, the present invention relates to cores having coils of electrically-conducting strand, such as insulated copper wire.  
         [0003]     For certain applications, present developments of dynamo-electric machines are leaning towards cores that no longer possess the ferromagnetic lamination stack. An extreme result of such development has led to ironless cores, in which the coils are suspended in air and need to be self-supporting to maintain their configuration. Self-support of the coil is a particular problem when the coil needs to be wound with thin wires. In fact, the turns of the coil can easily collapse if they are not supported. Self-support of the coil can be achieved as a result of the reticular structure which is imposed on the conducting wire when forming the coil. More particularly, the reticular structure is produced during winding by coursing the conducting wire along a highly meshed pattern and simultaneously laying it on a support structure. Self-support of the coil results when the conducting wire is well-meshed to form the reticular structure.  
         [0004]     As an alternative to the reticular structure for self-support of the coils, or as a supplement to enhance self-support of the coil, bonding of the conducting wire can be performed once the coils are formed. This bonding achieves that adjacent portions of the conducting wire are held together by an adhesive linkage, generated by a particular transformation of a surface component present on the conducting wire.  
         [0005]     Formation of the self-supporting reticular structure requires complex and time-consuming winding operations, while bonding the coils requires costly bondable wire. Furthermore, when the coil is not self-supporting and only bonding is used, operations for forming the coil (e.g., winding) need to use extremely accurate and complex solutions for supporting the coils until the bonding result has been achieved.  
         [0006]     The present invention provides a novel core and apparatus and methods for its manufacture, which avoid the need for the ferromagnetic lamination stack and reduce the difficulties of the prior art associated with self-supporting of the coils.  
       SUMMARY OF THE INVENTION  
       [0007]     In accordance with the present invention, apparatus and methods for winding dynamo-electric machine components are provided.  
         [0008]     The present invention provides a wound core, which is particularly suitable for being the stator core of a dynamo-electric machine. The core of the present invention may be wound with coils having a high number of turns, which substantially fill all the available space occupied by the core. Furthermore, the coils of the core of the present invention may be wound and interconnected according to a variety of electrical schemes.  
         [0009]     In some embodiments of the present invention, a dynamo-electric machine component may be provided. The component may include an annular body portion that is at least partially constructed from an insulating material. The component may include a plurality of members extending radially inward from the body portion forming a plurality of slots therebetween. The component may include wire coils that are received within the plurality of slots such that each wire coil extends from one slot of the plurality of slots to another slot of the plurality of slots.  
         [0010]     In some embodiments of the present invention, apparatus for assembling wire coils on a dynamo-electric machine component may be provided. Such a component may have an annular body portion and a plurality of members extending radially inward from the body portion forming a plurality of slots therebetween. The apparatus of the present invention may include a ram member configured to be received within the body portion of the component to position a first portion of the wire coils within the plurality of slots and a second portion of the wire coils across opposing axial end portions of the body portion. The apparatus may include an annular member configured to be received within the body portion when the ram member is withdrawn from the body portion such that the first portion of the wire coils maintains its positioning with respect to the slots.  
         [0011]     In some embodiments of the present invention, a method for assembling wire coils on a dynamo-electric machine component may be provided. Such a component may have an annular body portion and a plurality of members extending radially inward from the body portion forming a plurality of slots therebetween. The method of the present invention may include providing apparatus for assembling the wire coils on the component that includes a ram member and an annular member. The ram member may be advanced within the body portion of the component such that a first portion of the wire coils are positioned within the plurality of slots and a second portion of the wire coils are positioned across opposing axial end portions of the body portion. The annular member may be advanced within the body portion of the component when the ram member is withdrawn from the body portion such that the first portion of the wire coils maintains its positioning with respect to the slots.  
         [0012]     Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]      FIG. 1  is a perspective view of an illustrative core in accordance with the present invention.  
         [0014]      FIG. 2  is an axial sectional view of another illustrative core in accordance with the present invention, and as may be viewed from direction  2 -- 2  of  FIG. 5 .  
         [0015]      FIG. 3  is a view similar to that of  FIG. 2 , showing the perimeter extension which the coils of the core of  FIG. 2  may have in the case of a particular electrical scheme in accordance with the present invention. Furthermore,  FIG. 3  schematically and partially shows the manner in which the coils are connected to commutation sectors in the case of the particular electrical scheme in accordance with the present invention.  
         [0016]      FIG. 4  is a schematic view of the electrical scheme demonstrated in  FIG. 3  in accordance with the present invention.  
         [0017]      FIG. 5  is a perspective view from direction  5  of  FIG. 2  illustrating a coil which may be wound on the core of  FIG. 2  in accordance with the present invention.  
         [0018]      FIG. 6  is a view similar to  FIG. 2  with the addition of an internal core that is rotated by the core of  FIG. 2  in accordance with the present invention.  
         [0019]      FIG. 7  is a sectional view of yet another illustrative core as may be viewed from direction  7 -- 7  of  FIG. 2  in accordance with the present invention.  
         [0020]      FIGS. 8-10  are sectional views similar to  FIG. 7 , although rotated by 90°, illustrating manufacturing stages for producing the core of  FIG. 7  in accordance with the present invention.  
         [0021]      FIG. 11  is a sectional view from direction  11 -- 11  of  FIG. 8  in accordance with the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0022]      FIG. 1  shows a perspective view of an illustrative core in accordance with the present invention. Stator core  9  shown in  FIG. 1  includes a core body  10  made of insulating material. Core body  10  is provided with annular ring portion  10 ′ and inner portion  10 ″ having coil receiving slots  11 .  
         [0023]     One or more rings  12  of ferromagnetic material may be embedded in annular ring portion  10 ′. Radial laminates  13  of ferromagnetic material may be embedded in inner portion  10 ″ adjacent to the coil receiving slots.  
         [0024]     Coils of high density and of conducting wire of the type described, for example, in Becherucci et al. U.S. patent publication No. US 2004/0046476, published on May 8, 2003, which is hereby incorporated by reference herein in its entirety, may be located in coil receiving slots  11 . The manufacturing operations and equipment described, for example, in Becherucci et al. U.S. patent publication No. US 2004/0046476, may be used to form the coils and locate them in coil receiving slots  11 . Slot cover members with pole extensions, such as those described in Becherucci et al. U.S. patent publication No. US 2004/0046476, may be used to cover the coils when they have been located in coil receiving slots  11 .  
         [0025]     Rings  12 , laminates  13 , and the pole extensions augment and improve distribution of the field generated by the coils located in coil receiving slots  11 .  
         [0026]      FIG. 2  shows a sectional view of another illustrative core in accordance with the present invention. The structure of core  110  includes a support structure  111 , coils  112  (see also  FIG. 5 ) of wound wire, and barrel member  113 . Support structure  111  may be constructed, for example, of a plastic compound, and may include annular portion  111 ′, together with stemming neck portions  111 ″. Spacing  114  existing between adjacent neck portions  11 ″ may act as compartments, or slots, for receiving sections of coils  112  formed from wire turns  115 . Barrel member  113  may include a thin annular ring of ferromagnetic material, which may encircle support structure  111 . In order to optimize the use of the available magnetic field in core  110 , barrel member  113  may be constructed of a ferromagnetic material. The plastic compound of support structure  111  may, for example, imbed metal particles.  
         [0027]     Barrel member  113  and support structure  111  may be assembled together concentrically. In one example, barrel member  113  and support structure  111  may be joined to each other as a result of a plastic injection mold operation, in which barrel member  113  is used as an integral part of the mold and support structure  111  is formed by solidification of the injected plastic compound. Alternatively, support structure  111  may be produced separately, as a result of a plastic injection mold operation, and then fitted within barrel member  113 . In this alternative embodiment, anchoring between support structure  111  and barrel member  113  may be accomplished using a variety of joining techniques, such as, for example, adhesive, a press fit, or any other suitable joining technique.  
         [0028]     With particular reference to  FIGS. 3-5 , a coil  112  ( FIG. 5 ) may include segments  116  and  117  placed in spacing  114  of support structure  111 . External lines  120  of  FIG. 3  schematically show the extension of segments such as segments  118  and  119  of coil  112 , which may be placed across opposite axial ends  110 ′ of core  110 . Any one of the external lines of  FIG. 3  shows the extension of a segment, such as segment  118  or  119 , of a particular coil, where a segment such as segment  116  is placed in a spacing  114  (in  FIG. 3  numbered  1 - 22  in front of each spacing  114 ), and a segment such as segment  117  is placed in another spacing at a certain angular distance. In the example shown in  FIG. 3 , the angular distance corresponds to an angular distance of passing beyond ten spacings  114 . Adjacent neck portions  111 ″ delimit and contain segments  116  and  117  with respect to other segments  116  and  117 . In other words, neck portions  111 ″ act as walls which impede certain turns present in segments  116  and  117  from being accidentally positioned amongst turns of other segments  116  and  117 . Neck portions  111 ″ also have a force reaction effect on the coil turns to maintain the coil turns in the respective spacing  114  where they are positioned as a result of winding the coils. (As will be described hereinbelow, an annular member  205  (see  FIGS. 8-10 ) may be provided in connection with the manufacture of core  110  to impede the exit of coil turns from spacings  114 , which are otherwise completely free and open for the insertion of a high quantity of wire coils  112 .)  
         [0029]     Internal lines  121  of  FIG. 3  schematically show leads such as leads  123  or  124  (shown broken in  FIG. 5 ) connected to commutation sectors C (in  FIG. 3  numbered  1 - 11  adjacent each commutation sector). In  FIG. 3 , some of the leads  123  and  124  are shown departing from the commutation sectors and interrupted at the numbering of the spacing which contains the coil segment to which they belong. Other leads  123  and  124  depart from the commutation sectors and are connected to segments  118  and  119  of adjacent coils (although these other leads are shown interrupted at a black dot in  FIG. 3 ).  FIG. 4  shows a schematic view of a complete coursing of leads  123  and  124 . In  FIG. 4 , horizontal lines are interrupted at the left and the right sides of the FIG. Such lines are meant to be connected to each other. In other words, a line numbered with a certain reference at the right of the FIG. is in actuality connected to a line having the same reference at the left of the FIG.  
         [0030]     The electrical scheme represented in  FIGS. 3-5  is typically that of a DC motor in which core  110  is the stator core with the field switched by mechanical commutation. For example, the commutation sectors shown in  FIG. 3  may be assembled as a commutator which is contacted by current conducting brushes rotating with an internal rotor  126  ( FIG. 6 ) placed within core  110 . For the described electrical scheme, internal rotor  126  may have two-pole permanent magnetization, as shown in  FIG. 6  by the example of North N and South S magnetic sectors placed on internal rotor  126 .  
         [0031]     Segments  116  and  117  provide conducting paths for electric current to create symmetric lines of magnetic fluxes M for circulation, as shown in  FIG. 6 . Magnetic fluxes M exit or enter neck portions  111 ″, pass through internal rotor  126 , and close themselves by passing through barrel member  113  (in  FIG. 6 , some of the magnetic fluxes in barrel member  113  have been shown interrupted for reasons of clarity). The magnetic fluxes pass through annular air gap  125  existing between neck portions  111 ″ and internal core  126  to produce thrust forces on internal core  126  for causing motion of the internal core. Internal core  126  may be provided with current circulating means to provide magnetization, as would be required in applications with AC supply to core  110  and internal core  126 .  
         [0032]     Winding of coils such as coil  112  of  FIG. 5 , and the placement of segments  116 ,  117 ,  118 , and  119  within respective spacings  114  of core  110 , may be achieved by first rotating a wire dispensing flyer around a template to form the coils, and then transferring the coils from the template to selected spacing existing between insertion blades of an insertion tool, as is the technique used for winding coils of induction motor. Once the coils have been placed on the insertion tool, a ram may be passed through the hollow area existing between the insertion blades so that the coils become inserted in respective spacings  114  of core  110  where they need to be allocated. More particularly, core  110  may be aligned over the insertion tool so that the spacing between the insertion blades where segments  116  and  117  are positioned are aligned with spacings  114  for which allocation needs to occur. This technology of winding and inserting the coils in a stator of an induction motor is described, for example, in Becherucci et al. U.S. Pat. No. 6,557,238, which is hereby incorporated by reference herein in its entirety. The wire leads such as wire leads  123  and  124  exiting the coils may be treated as described, for example, in Stratico et al. U.S. patent application Ser. No. 10/817,715, which is hereby incorporated by reference herein in its entirety, in order to course the leads as has been described in the foregoing. A variety of different electrical schemes for core  110  may be accomplished by using the previously mentioned winding, inserting and lead coursing techniques together with core  110  of the present invention. For example, core  110  may be wound according to an electrical scheme so that it can be electronically commutated, as is required in stators of brushless motors, or it can be wound so that it becomes the stator of a variable reluctance motor.  
         [0033]     As stated hereinabove, neck portions  111 ″ act as containing walls for the turns forming segments  116  and  117  of the coils, thereby maintaining the segments in specific allocated spacing  114  as a result of the insertion operation. Consequently, the magnetic energy produced by core  110  is maximized due to the predetermined positioning of the coil turns in spacing  114 . Furthermore, portion  111 ′ may act as an electrical insulation barrier between the coil turns and barrel member  113 .  
         [0034]     The coil turns may be secured in spacing  114  using, for example, wedge solutions such as those described in Becherucci et al. U.S. patent publication No. US 2004/0046476, published Mar. 11, 2004, which is hereby incorporated by reference herein in its entirety. Alternatively, the coil turns may be secured by filling the gaps existing between coils turns with a plastic compound which bonds the coil turns together. More particularly, the plastic compound may be pressure injected into spacing  114  when segments  116  or  117  are present. A calibration mold member may be fitted within the hollow of core  110  which mates with neck portions  111 ″. The calibration mold maintains the plastic compound within spacing  114  during the pressure injection operation, and outside a predetermined diameter of core  110  in order to assure the necessary air gap  125  between core  110  and internal core  126 .  
         [0035]      FIG. 7  shows a sectional view of yet another illustrative core in accordance with the present invention. (It should be noted that numbering in connection with the embodiment of  FIG. 7  will be the same as the numbering for core  110  of  FIG. 2  for like portions of the cores.) In particular,  FIG. 7  shows that barrel member  113  and support structure  111  of core  110  may be modified along their extension. More particularly, support structure  111  may have annular portions  200  and  201 , which enclose segments  118  and  119  of the coils. Furthermore, barrel member  113  may have annular portions  202  and  202 ′ encircling annular portions  200  and  201 .  
         [0036]      FIGS. 8-10  show illustrative manufacturing stages for producing the core of  FIG. 7  in accordance with the present invention. It should be noted that certain portions of  FIGS. 8-10  are shown transparent and/or without hatching for clarity.  
         [0037]      FIG. 8  shows a manufacturing stage in which core  110  is positioned over an insertion tool  203 , which is configured as a circular array of insertion blades  203 ′. Furthermore, ram  204  has passed through insertion tool  203  and is located within core  110 . (For reasons of clarity, ram  204  is shown as transparent.) As a result of this manufacturing stage, segments  116  and  117  of coils  112  are located within spacing  114  as shown in  FIG. 2 , and segments  118  and  119  of the coils are placed across axial ends  110 ′ of core  110 . Also shown in  FIG. 8  is member  205  which is axially aligned with ram  204  and in contact with ram  204  along lower end  205 ′ of member  205 . Member  205  may be maintained in alignment with ram  204  by inserting guide rod  211  of ram  204  in central seat  205 ″ of member  205 . The insertion of guide rod  211  in central seat  205 ″ may occur when ram  204  moves in direction A to reach the position which it has in  FIG. 8 , while member  205  is already aligned as shown in  FIG. 9 .  
         [0038]      FIG. 9  shows a successive stage in which ram  204  has been withdrawn from the core and has been replaced by member  205  (shown transparent in  FIG. 9 ). Member  205  reaches the position which it has in  FIG. 9  by being lowered in a direction opposite to direction A with a pushing means (not shown). This may occur, for example, when ram  204  is being withdrawn from the core with a movement in a direction opposite to direction A. The corresponding motion of member  205  in a direction opposite to direction A may be such that contact at surface  205 ″ with ram  204  is always maintained until portion  205 ′″ of member  205  has passed beyond segments  119  placed across lower axial end  110 ′ of core  110 . Member  205  may be configured like a cylinder having an outer diameter D, which allows it to mate with neck portions  111 ″. In such an example, member  205  acts as a barrier which impedes the exit of coil turns from spacing  114  when ram  204  is being withdrawn from the core. Furthermore, member  205  pushes segments  118  and  119  of the coils firmly against portions  200  and  201  when member  205  is being lowered though the core, thereby causing member  205  to act as former of segments  118  and  119  of the coils.  
         [0039]     Also shown in  FIGS. 8, 9 , and  11  is gripper unit  206  having gripping portions  207  and  208 , extending from arms  206 ′ and  206 ″, in order to grasp barrel member  113 . A firm grasp on barrel member  113  keeps core  110  referenced with respect to the other parts shown in  FIGS. 8 and 9  (e.g., ram member  204 , member  205 ).  
         [0040]      FIG. 9  shows that member  205  has passed through the upper portion  212  of gripper unit  206  and that gripper unit  206  is being moved to transfer core  110  and member  205  to a different location, such as the station illustrated in  FIG. 10 .  
         [0041]      FIG. 10  illustrates a manufacturing stage in which pressing cups  209  and  210  press against segments  118  and  119 , respectively. More particularly, pressing cup  209  presses against segment  118  by pressing in direction C, while pressing cup  210  presses against segment  119  by pressing in direction D. The combination of these pressing operations sizes segments  118  and  119  in directions C and D, which are substantially perpendicular to the planes of axial ends  110 ′ of core  110 . Portions  209 ′ and  210 ′ of pressing cups  209  and  210 , respectively, act as force reacting walls against the tendency of segments  118  and  119  to expand outwardly when the pressing cups press against segments  118  and  119 . Similarly, the outer surface of member  205  acts as a force reacting wall against the tendency of segments  118  and  119  to expand inwardly.  
         [0042]     In some embodiments, a molten plastic compound may be pressure injected into spacing  114  to secure the coil turns, as described hereinabove. The molten plastic compound may be fed from a pressure injection unit (not shown) to spacing  114  through channels of pressing cups  209  and  210 , and through channels of member  205 . Member  205  (shown transparent in  FIG. 10 ) may function as a calibration mold member, as described hereinabove.  
         [0043]     It will be understood that the foregoing is only illustrative of the principles of the present invention, and that still other modifications can be made by those skilled in the art without departing from the scope and spirit of the invention.