Abstract:
The present invention is concerned with the driving mechanism of winding needles which dispense wire to form the wire coils of a dynamo-electric machine component. Generally, such wire winding is achieved by providing translational, rotational, and radial motions to the winding needle relative to a reference structure of the component. The present invention provides wire winding solutions for causing the winding needles to accomplish predetermined motions with respect to the component so that wire is predictably positioned on the component to form the wire coils. In particular, the present invention provides a driving mechanism with coaxial hollow shafts that impart the necessary motions to the winding needle. In one aspect of the invention, the inner shaft is able to mirror the rotation of the outer shaft to provide rotational motion to the winding needle. In another aspect of the invention, the outer shaft is able to impart both translational and rotational motion via coaxially disposed rotatable sleeves driven by motors. In yet another aspect, all of the winding motions are coordinated using a programmable control mechanism.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
   This application claims the benefit of priority from U.S. provisional patent application No. 60/447,966, filed Feb. 13, 2003, which is hereby incorporated by reference herein in its entirety. 
   BACKGROUND OF THE INVENTION 
   The present invention concerns solutions for winding coils of wire onto dynamo-electric machine components. More particularly, the present invention is concerned with the driving mechanism of winding needles which dispense wire to form the coils by moving with respect to a reference structure (e.g., poles) of the core body of the component. 
   Wire coils may be wound onto the poles of a lamination core or may be wound onto themselves in components that do not require or possess poles. The wire coils form magnetic fields required in the use of components belonging to dynamo-electric machines. More particularly, the wire coils can be associated with poles of the core body of the components in order to enhance and distribute the magnetic field for generating the final power output required from the dynamo-electric machines. For example, the previously mentioned lamination core may be either a stator core or an armature core of a dynamo-electric machine. The dynamo-electric machine as a whole may be an electric motor, which is used for many types of driving applications. 
   The ongoing improvement of the performance obtained from dynamo-electric machines has led to various improved geometric designs for the poles of a dynamo-electric machine component. These improved designs usually require extremely variable location of the wire coils. At the same time, the wire turns which form the coils on the component must also be orderly positioned with respect to the poles in order to occupy the areas adjacent to the poles with the maximum amount of wire turns. 
   In view of the foregoing, it is an object of the present invention to provide wire winding solutions for causing the winding needles to accomplish predetermined motions with respect to the component so that wire is predictably positioned on the component to form the wire coils. It is a further object of the present invention to provide winding needles that accomplish a combination of translational motion, rotational motion, and radial stratification motion with respect to the component. It is a still further object of the present invention to provide coaxial hollow shafts to impart these necessary motions to the winding needle. 
   These and other objects of the present invention will be more apparent in view of the following drawings and detailed description of the preferred embodiments. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Non-limiting embodiments of the present invention are described hereinafter with reference to the accompanying drawings in which: 
       FIG. 1  is a partial axial view of a core body and a partial sectional view of a portion of a winding needle; 
       FIG. 1A  is a projection of a trajectory used to wind a turn of a coil around a conventional pole from a view similar to that of  FIG. 2   
       FIG. 2  is a view from direction  2  of  FIG. 1  showing the projection of a trajectory accomplished by a portion of a winding needle to wind a turn of a coil around the pole of  FIG. 1 ; 
       FIG. 3  is a partial sectional view of a winding needle assembly as seen from direction  3 — 3  of  FIG. 1  with the needle portion shown in  FIG. 2  positioned in the plane of direction  3 — 3 ; and 
       FIG. 4  is a partial sectional view of an embodiment of a driving mechanism for the needle assembly which is a continuation (to the left) of the view shown  FIG. 3 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The solutions of the present application are generally related to those described in commonly assigned Stratico et al. U.S. Pat. No. 6,622,955, which is hereby incorporated by reference herein in its entirety. 
   Typically, to form a wire turn around a conventional, rectangular shaped pole, the winding needle is moved around the pole with the trajectory shown in  FIG. 1A . Such a trajectory would include translation strokes T 1  and T 2 , which would be into and out of the page, respectively, in  FIG. 1 . These translation strokes move the winding needle along the pole for a travel which starts at one end of the core body and ends at the other end of the core body. Between the translation strokes, when the needle is positioned at the end of the core body, the winding needle accomplishes rotational strokes +R and −R to move from one side of the pole to the other side of the pole. More specifically, with reference to  FIG. 1A , at the end of translation stroke T 2  (where the winding needle is at the end of the core body closest to the viewer in  FIG. 1 ), the needle accomplishes rotational stroke +R to move from the left side of the pole to the right side of the pole. In  FIG. 1 , this movement would be analogous to moving needle  12  from side  11 ′ of the pole to side  11 ″ with the needle at the end of the core nearest to the viewer. Similarly, at the end of translation stroke T 1 , the needle accomplishes a rotational stroke −R. In  FIG. 1 , this is analogous to needle  12  moving from side  11 ″ of the pole to side  11 ′ of the pole when needle  12  is at the end of the core body that is farthest from the viewer. With reference to  FIG. 1A , the combination of these motions (T 1 , T 2 , +R, −R) causes the needle to travel around the conventionally shaped pole in order to dispense the wire that forms the turn of a coil. In addition to the translational motions and the rotational motions, radial stratification motions S 1  and S 2  (out of the page and into the page, respectively, in  FIG. 1A ) are also provided to regularly stratify the wire turns along the radial extension of the pole. In the following, the rotational strokes +R and −R will be referred to collectively as ±R. 
   It can be clearly seen that the conventional winding trajectory used in  FIG. 1A  cannot accommodate a pole with unconventional geometry, such as pole  11  of  FIG. 1 .  FIG. 1  shows that the pole structure is slanted at an angle in its extension between the ends of the core body. This type of pole structure can resemble a helical blade and requires angular rotation of the needle when moving along its slanted axial extension. A pole structure having such a configuration must be wound by a needle which moves to closely follow the slanted contour of the pole structure. The objective of which is to precisely locate the wire and avoid collision with the pole structure itself. Collision most frequently occurs when wire dispensing tip  12 ′ of the winding needle is required to move within the slots formed by adjacent pole structures  11  shown in  FIG. 1 . In such a situation, the winding needle is required to move between obstacles such as edges  11 ′″ of two adjacent pole structures in order to place wire into spaces  11 ′ and  11 ″. These additional aspects of placing a wire turn in an unconventional trajectory require the winding needle to achieve motions in addition to motions ±R, T 1  and T 2 , S 1 , and S 2 . 
   The illustrated embodiment of the present invention shows the winding of wire around the pole of a stator core. However, it should be understood that although the following description concentrates on an embodiment in which the wire coils are wound around a single pole, the present invention may be used to simultaneously wind a wire coil through multiple poles. Similarly, the present invention may be used to wind wire coils around virtual poles in which no physical pole exists on the stator core. In the case of a virtual pole, wire coils are wound around each other about a theoretical pole axis on the stator. This type of stator may allow even more wire coils to be placed within a set amount of space in the core and are fully contemplated by the present invention. Although no obstacle such as edge  11 ′″ are present in a virtual pole situation, the winding needle still requires accurate motion along the trajectory shown in  FIG. 2  because the turns of specific wire coils need to be located accurately in order to optimize the available spacing of the stator. 
     FIG. 2  shows a trajectory required of the wire dispensing tip of a needle in order to wind a turn of a coil around a pole structure like the one shown in  FIG. 1 . Due to the geometry of pole  11 , winding needle  12  must make additional rotational deviations ±∂R to accomplish the trajectory shown in  FIG. 2 . ±∂R indicates increments of rotational motion R which may be in the sense of rotation +R or −R. In the case of the trajectory shown in  FIG. 2 , rotational deviations ±∂R need to be applied at least during translations T 1  and T 2  to obtain the slanted strokes P 1  and P 2 . Otherwise, P 1  and P 2  would be parallel to translation directions T 1  and T 2  shown in  FIG. 2  and may cause the winding needle to collide with the pole structure. 
   A needle assembly capable of the above-described motions is shown in  FIG. 3 . More specifically, needle  12  extends from needle arm  15 , which is cantilevered from slide portion  15 ′. Slide portion  15 ′ is assembled on two spaced apart guides  17 , of which only one is shown in  FIG. 3 . Guides  17  are fixed to arm portions  18 ′ of carrier member  18 . Disk member  19  is provided with a curved groove  19 ′ (e.g., a spiral curved groove) which receives pin  16  extending from slide portion  15 ′. 
   As a result of the above assembly, rotation of disk member  19  with respect to carrier member  18  about reference axis X causes slide portion  15 ′ to move along guides  17  substantially perpendicular to axis X. This radial stratification motion is achieved through the constraint of pin  16  sliding within groove  19 ′. Needle  12  can accomplish radial translations S 1  or S 2  by rotating disk member  19  by rotational values ±θ around axis X with respect to carrier member  18 . ±θ indicates a clockwise or counter clockwise rotation of value θ. 
   In addition to the stratification motion, needle  12  can accomplish rotational motions ±R by simultaneously rotating both carrier member  18  and disk member  19  about axis X with identical rotational values ±R. Furthermore, needle  12  can accomplish translational motions T 1  or T 2  by simultaneously translating carrier member  18  and disk member  19  substantially parallel to axis X. 
   Additional motion like rotational deviations ±∂R of needle  12  can be accomplished by simultaneously rotating carrier member  18  and disk member  19  around axis X by an increment of ±∂R. The combination of rotational deviations ±∂R with translations T 1  and T 2  produce strokes P 1  and P 2  of needle  12 , which conform to the shape of pole  11  shown in  FIG. 1 . 
   In order to impart these motions to carrier member  18  and disk member  19 , carrier member  18  may be fixed to an outer shaft  20  and disk member  19  may be fixed to an inner shaft  21 . In the following, it will be shown that outer shaft  20  may be assembled external and coaxial to inner shaft  21  along axis X. 
   Furthermore, outer shaft  20  and inner shaft  21  may be fixed with respect to each other in the sense of their axial length parallel to axis X, and simultaneously be capable of rotation with respect to each other about axis X. 
   Outer shaft  20  and inner shaft  21  may be provided with rotational motions ±R and ±∂R, translation motions T 1  and T 2 , and relative rotation ±θ. Each of these motions may be individually driven by motors M 0 , M 1 , and M 2  (which will be more fully described in the following) that may be programmable and controlled to assure that desired values of each motion are achieved with precision, according to required sequences, and at predetermined times. Necessarily, the torque characteristics of the motors are also programmable and controlled to impart each of the motions and to act with a drag effect when required. 
   Rotational motions ±R and ±∂R, translational motions T 1  and T 2 , and relative rotations ±θ may be combined by control equipment of the winder so that winding needle  12  is able to move with trajectories that match a variety of pole configurations. This capability of the winder will assure successful winding of a variety of pole configurations and produce a predictable placement of the wire turns which form the coils. 
   As shown in  FIGS. 3 and 4 , disk member  19  is fixed to inner shaft  21  by having an internal thread  50  which may be screwed onto a corresponding thread of inner shaft  21 . Furthermore, ring nut  51  is also screwed onto the thread of inner shaft  21  to secure disk member  19  against any unwanted loosening. Carrier member  18  is sleeved on to outer shaft  20  and is clamped onto shaft  20  by a clamping member (not shown). Positioning of disk member  19  on inner shaft  21  is further achieved by pushing disk member  19  against axial bearing  52 . Axial bearing  52  also abuts against carrier member  18  when the carrier member is clamped to outer shaft  20 . In this way, outer shaft  20  and inner shaft  21  are fixed with respect to each other in the axial direction parallel to axis X but remain capable of rotation with respect to each other about axis X. 
   With particular reference to  FIG. 4 , front sleeve  22  is assembled on bearings  22 ′, which are in turn assembled in frame structure  23  of the winder. This configuration makes front sleeve  22  capable of rotation around axis X. Gear wheel  24  is assembled to front sleeve  22  by means of a flange type connection using bolts  25 . Pinion gear  26  of motor M 0  engages gear wheel  24 . The inside of front sleeve  22  is provided with channels of a helix, which seat portions of bearing balls  27 . Similarly, outer shaft  20  is provided with a corresponding helical channels  28  that seat other portions of bearing balls  27 . In this way, rotations imparted by motor M 0  are translated into translational motions, such as T 1  or T 2 , of outer shaft  20 . The value of these translational motions are proportionally depend the pitch of the helical channels  28  and the number of turns accomplished by motor M 0 . 
   As shown in  FIG. 4 , intermediate sleeve  29  is assembled on bearings  29 ′, which are in turn assembled in frame structure  23  of the winding machine. This configuration enables intermediate sleeve  29  to rotate around axis X. Gear wheel  30  is positioned with respect to intermediate sleeve  29  by means of a flange type connection using bolts (shown but not numbered). Pinion gear  32  of motor M 1  engages gear wheel  33 . Gear wheel  33  is part of support shaft  34 , which is mounted idle on frame structure  23 . Gear wheel  33  engages gear wheel  30 . The inside of intermediate sleeve  29  is provided with linear keyways  29 ′, which are disposed parallel to axis X. Similarly, outer shaft  20  is provided with linear keyways parallel to axis X. Bearing balls  29 ″ similar to bearing balls  27  have portions placed in both keyways so that key connections are made between intermediate sleeve  29  and outer shaft  20 . In this way, rotations imparted by motor M 1  result in the transmission of rotational motions such as ±R and ±∂R to outer shaft  20 . 
   As will be shown in the following, rotational motions ±R and ±∂R of outer shaft  20  can be simultaneously and identically transmitted to inner shaft  21 . The transmission of identical rotational motion to inner shaft  20  enables disc  19  and carrier member  18  to rotate together simultaneously and by an identical rotational value such that there is no relative rotation between inner and outer shafts. This configuration enables the smooth rotation of needle  12  about axis X and does not allow the winding needle to move radially unless relative rotations ±θ are imparted to the inner shaft by motor M 2 . 
   As shown in  FIG. 4 , gear wheel  30  is engaged by gear wheel  35 . Gear wheel  35  is part of support shaft  36 ′ mounted idle on frame structure  23 . Gear wheel  36  is also part of support shaft  36 ′ and engages gear wheel  37 . Gear wheel  37  is mounted coaxially around intermediate sleeve  29  and is supported on bearings  38  mounted on an external portion of intermediate sleeve  29 . In addition, gear wheel  39  engages gear wheel  37 . Gear wheel  39  is part of shaft  40  mounted idle on ring  41 . Gear wheel  42  is also part of shaft  40 . 
   Gear wheel  42  engages gear wheel  43  which is connected to the end of rear sleeve  44  by means of a flange type connection using bolts (shown but not numbered). Rear sleeve  44  is provided with keys and key ways  45  which engage corresponding keys and keyways present on the outer surface of inner shaft  21 . Rear sleeve  44  is mounted on bearings  46  of frame structure  23 . Ring  41  is disposed around rear sleeve  44  and is supported on bearings  47 , which are mounted on an external portion of rear sleeve  44 . Thus, rotations like ±R and ±∂R imparted by motor M 1  to intermediate sleeve  29 , may be transmitted through the chain of gear wheels  35 ,  36 ,  37 ,  39 ,  42  and  43  to rear sleeve  44 . Ultimately, this configuration simultaneously transmits the same rotational motions to inner shaft  21  as are being provided to outer shaft  20  by motor M 1 . 
   Radial stratification motions S 1  or S 2  may be obtained by imparting relative rotations ±θ to inner shaft  21 . As shown in  FIG. 4 , this can be achieved by mounting gear wheel  48  on ring  41  and engaging pinion wheel  49  of motor M 2  with gear wheel  48 . In this configuration, motor M 2  can impart relative rotations ±θ to rear sleeve  44  by means of the chain of gear wheels  49 ,  48 ,  42 , and  43 . Ultimately, this imparts relative rotations ±θ to inner shaft  21  through the connection of keys and keyways  45 . 
   With reference to  FIG. 4 , it can be seen that inner shaft  21  is supported along its length by outer shaft  20  and by sleeve  44  at the left hand side of the drawing. Sleeve  44  is supported on frame structure  23  through bearings  46 . Inner shaft  21  and outer shaft  20  are also supported with respect to frame structure  23  by bearing balls  27 , which are disposed between outer shaft  20  and intermediate sleeve  29  as well as between outer shaft  20  and front sleeve  22 . Intermediate sleeve  29  contacts frame  23  through bearings  29 ′. Front sleeve  22  contacts frame  23  through bearings  22 ′. 
   In order to combine rotation motions ±R and ±∂R, translation motions T 1  and T 2 , and relative rotation ±θ so that winding needle  12  is able to move with trajectories that match a variety of pole configurations, motors M 0 , M 1  and M 2  are connected to power and control unit  53  via respective signal and supply lines  54 ,  55 , and  56 . Power and control unit  53  comprises a clock, microprocessor, memory, and programming hardware to command motors M 0 , M 1  and M 2  to apply torque and speed performance which synchronizes motions ±R and ±∂R, translation motions T 1  and T 2 , and relative rotation ±θ according to programmed algorithms. The programmed algorithms will be directly related to the trajectories of needle  12  that are required to conform to the geometry of various pole structures. 
   During the motions of needle  12 , wire  13  may travel through inner shaft  21 , as shown in  FIGS. 3 and 4 . Wire  13  comes from a wire store (not shown) that is to the left of rear sleeve  44 , and travels towards needle  12 . Wire  13  may be tensioned during its travel from the wire store to needle  12  by using a wire tensioning unit (not shown), which applies tension on wire  13  at a location that is between the wire store and rear sleeve  44 . 
   Thus, improved systems and methods for providing a dynamo-electric machine component wire winding apparatus is provided. One skilled in the art will appreciate that the present invention can be practiced by other than the described embodiments, which are presented for the purpose of illustration and not of limitation.