Patent Abstract:
An apparatus for moving wire dispensing members used to wind dynamo electric machine coils comprising a frame; a first tubular member having a longitudinal axis assembled for longitudinal reciprocation parallel to said longitudinal axis; a second tubular member assembled for longitudinal reciprocation and rotational oscillation; means for generating the translational reciprocation motion of said first and second tubular members; means for generating rotational oscillation of said first and second tubular members; means for generating a relative rotational motion between the first and second tubular members for accomplishing a radial motion of the wire dispensing members; wherein the means for generating the translational reciprocation motion are assembled on a first shaft and the means for generating rotational oscillation are supported for the rotational oscillation with support means assembled on the frame, and the means for generating the rotational oscillation derive rotational motion from the first shaft through a transmission joint.

Full Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to solutions for winding coils of core components of dynamoelectric machines, and more particularly to apparatuses for winding stator cores, like those employed in brushless motors. 
         [0002]    Although the invention is particularly described with reference to stator cores, the principles of the invention are equally applied to other cores that need to be wound with wire conductor. 
         [0003]    With brushless motors it is known to use cores having wire coils wound by moving one or more needles to dispense tensioned wire. To form a coil having a plurality of turns the wire exits the moving needles and becomes appropriately positioned in the core. The needles move for a predetermined number of cycles to generate a certain number of complete turns, which form the finished wound coils. 
         [0004]    The cycle accomplished by a needle is normally a combination of reciprocating translations, reciprocating rotations and incremental radial movements, as described for example in publication EP 1191672. 
         [0005]    Schematically, a turn of a coil is a closed rectangular extension of wire having two rectilinear sides joined by two shorter sides. In general, a series of turns forming a coil consist o a plurality of the rectangular extensions piled in an orderly manner with the sides positioned consistently. 
         [0006]    By piling of the coils in an orderly manner, the space occupied by the coil in the core results optimized, therefore interference contact of the turns with the surrounding structure is avoided. 
         [0007]    Normally, the two long sides of the rectangular extension of the coil are produced by the axial translations accomplished by the needles dispensing the wire. The rotation movements accomplished by the needles dispense the wire to form the two lateral stretches, which are usually the short sides of the coils. The incremental radial translations pile the turns in different planes of the coil, i.e. at various depths of the slots of the core—a phenomena usually referred to as “stratification” of the turns. 
         [0008]    The needles are moved with kinematic solutions driven by rotation of an input motor to accomplish the foregoing movements, like is described in the above mentioned EP 1191672. 
         [0009]    In publication EP 318 063 a more limited solution is described. In this case the needles do not move in the radial direction to achieve the stratification. 
         [0010]    The different kinematic solutions existing in the art significantly influence both the precision with which the needles are positioned to form the coils, and also the speed with which the needles move to dispense the wire. 
         [0011]    In other words, the kinematic solutions are important not only for the precision with which the turns become positioned in the coil, but also for the time required to place all the turns to form the finished coils. This is particularly influenced by the mechanical transmissions, the tolerances, the inertia of the parts of the various kinematic solutions, and also due to the position of theses inertias in space. 
         [0012]    The winding requirements of coils in brushless cores are particularly focused on positioning of the turns with the maximum precision within the available space of the core of the electric machine. At the same time, higher speed of the movement of the needles is required to increase productivity. The end result is a production of wound cores at high speed with the coils being compact and having a high number of turns. 
         [0013]    A further objective is that the movement of the needles needs to be easily and accurately adjusted to adapt the winding parameters to a wide variation of core configurations. In particular, the translation movements, the rotation movements, and the radial displacement of the needles respectively need to cover paths, accomplish angles and travel at slot depths that allow the coil turns to be precisely positioned within specific geometries of the cores. 
         [0014]    For the same reason, these movements of the needles need to be accomplished in different stages of a temporal cycle, which is required to wind the coils. 
         [0015]    Based on the foregoing description, it is an object of the present invention to provide an improved apparatus for winding electric machine coils. 
         [0016]    It is also a particular object of the invention to provide an improved apparatus that causes the needles to accomplish translation movements, rotation movements and radial movements with more accurate positioning of the needles during the winding stages. 
         [0017]    It is also an object of the present invention to provide an improved apparatus for accomplishing the translation movements, the rotation movements and the radial movements of the needles at a higher speed to increase the productivity of wound coils. 
         [0018]    It is also an object of the present invention to provide an apparatus that has solutions which are easily adjustable for winding different core configurations, whilst maintaining the foregoing advantages of positioning accuracy and high speed movement of the needles. 
         [0019]    A further object of the invention is to provide an apparatus that is more simple to manufacture due to the low number of parts, and for the fact that the parts are of simple configuration and can be easily assembled. 
       SUMMARY OF THE INVENTION 
       [0020]    The invention relates to a novel solution having movable members (needles) for dispensing wire to form the wire coils in the winding stage by translating in an axial direction with respect to the core, rotating with respect to the core, and translating in a radial direction with respect to the core. 
         [0021]    A first tubular member, which supports at least one wire dispensing member, can translate in the axial direction and rotate with respect to the core. Furthermore, a second tubular member can be assembled coaxially with respect to the first tubular member and can rotate with respect to the first tubular member to radially translate the wire dispensing member in relation to the core. 
         [0022]    Means are provided for converting the relative rotation between the first tubular member and the second tubular member to translate the wire dispensing member in the radial direction with respect to the core. 
         [0023]    The invention is also applicable in the case of multiple wire dispensing members, which can be supported by the first tubular member to be translated in the axial direction and rotated with respect to the core. 
         [0024]    Similarly, the multiple wire dispensing members can be translated in the radial direction with respect to the core by rotating the second tubular member with respect to the first tubular member. 
         [0025]    Each of the wire dispensing members can release wire in order to form a coil around a respective pole of the core. In this way, multiple coils can be wound simultaneously. 
         [0026]    These and other objects are accomplished by means of the apparatus according to claim  1 . 
         [0027]    Other characteristics of the invention are indicated in the dependent claims. 
         [0028]    Further characteristics of the invention, its nature and various advantages will result more clearly from the enclosed figures and the following detailed description of the preferred embodiments. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0029]    In the enclosed figures: 
           [0030]      FIG. 1  is a partial section elevation view of the apparatus for moving the wire dispensing members according to the principles of the present invention; 
           [0031]      FIG. 2  is a partial section view as seen from directions  2 - 2  of  FIG. 1 ; 
           [0032]      FIG. 3   a  is a partial view as seen from directions  3  of  FIG. 1  illustrating a lever mechanism. The upper part of the lever mechanism is a view from directions  3 ′- 3 ? of  FIG. 4 . In  FIG. 3   a  certain parts of the apparatus of  FIG. 1  have been omitted for reasons of clarity. 
           [0033]      FIG. 3   b  is a view similar to the view of  FIG. 3   a  with the lever mechanism of the apparatus positioned differently with respect to the position of  FIG. 3   a.    
           [0034]      FIG. 4  is a partial section view of the area  4  of  FIG. 1 .  FIG. 4  is similar to FIG. 1 of publication EP 1191672, however in the solution of  FIG. 4  of the present invention certain modifications are present, as is described in this application. 
           [0035]      FIG. 5  is a view similar to the view of  FIG. 3   a , although illustrating a different embodiment of the invention. 
           [0036]      FIG. 6  is a view as seen from directions  6 - 6  of  FIG. 4  in the case of the embodiment of  FIG. 5 . 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0037]      FIG. 1  illustrates a first assembly  10  comprising a needle  11  for dispensing wire W to wind coils around the poles of a core. 
         [0038]    The needle  11  translates with reciprocating motion in directions T and T′, parallel to longitudinal axis  12 . In addition needle  11  rotates with an angular alternative motion in directions S and S′ around longitudinal axis  12  and translates with forward and backward radial motion in directions R and R′, which are perpendicular to axis  12 . 
         [0039]    The trajectory accomplished by needle  11  is similar to the trajectory of the needle described in publication EP 1191672. Relative rotations between the external tube  13  and the internal tube  14  in directions S and S′ (see also  FIG. 4 ) obtain that needle  11  translates in the radial directions R and R′ for stratification. The relative rotations of external tube  13  and internal tube  14  are generated by motor  60 , which transmits rotations in the directions S and S′ to internal tube  14  through assembly  118  (see  FIGS. 1 and 4 ) to achieve the stratification displacements in directions R and R′. 
         [0040]    The principles of this transmission are similar to those described in publication EP 1191672—see  FIG. 1  of this publication where motor  164  is similar to motor  60  of the present application, whilst assembly  118  and assembly  126  of FIG. 1 of publication EP 1191672 are respectively similar to assemblies  118  and assembly  126  of  FIGS. 1 and 4  of the present application. 
         [0041]    With reference to  FIGS. 1 and 4  of the present invention, tubes  13  and  14  are assembled integral with each other for translating together in directions T and T′, therefore, the motion of translation backwards and forwards in the directions T and T′ of needle  11  parallel to longitudinal axis  12  occurs by translating tubes  13  and  14  together in directions T and T′. 
         [0042]    This translation is generated by assembly  16  comprising arm  15 , which is connected through moveable hinge  17  (shown with dashed line in  FIG. 1 ) to internal tube  14 . The ring  16 ′ (shown with dashed line in  FIG. 1 ) is assembled inside arm  15  to be coaxial with axis  19  of shaft  20 , and is caused to rotate together with shaft  20  by means of the connection to sleeve  51  through lever  50 . In fact, sleeve  51  is integral with shaft  20  in the rotation direction around axis  19 , whilst for the adjustment of the translation path in directions T and T′ (see the following), sleeve  51  is able to move parallel to axis  19  due to the key and slot connection  51 ′. 
         [0043]    Assembly  16 , and thus arm  15 , accomplishes the oscillations OS and OS′ around axis  18  of the pin present on shaft  20  due to the rotations of ring  16 ′ in arm  15 , and the inclined position of arm  15  caused by the position of sleeve  51  along shaft  20 . Axis  18  is positioned perpendicular to axis  19  of main shaft  20 . The oscillations OS and OS′ of arm  15  are transformed into backwards and forward translations in directions T and T′ of the internal tube  14 , and therefore also into backward and forward translations in directions T and T′ of external tube  13 . Assembly  16 , arm  15 , and hinge  17  are similar to the assembly that generate the translations in publication EP 318 063—see FIG. 1 of this document, however, in the present case hinge  17  is also capable of allowing the rotations of shaft  14  in directions S and S′. 
         [0044]    Shaft  20  is assembled on bearings  21  and  22  to rotate around axis  19  and thus generates the oscillations OS and OS′ of arm  15 . In particular, motor  24  and the belt transmission  23  (see also  FIG. 2 ) rotate shaft  20  around axis  19  to generate the oscillations OS and OS′. Therefore, motor  24  indirectly obtains the forward and backward translations in directions T and T′ of the needles like  11 . With reference to  FIG. 1 , gear wheel  25  assembled on the end of shaft  20  engages with the gear wheel  26  assembled on the input shaft  27  of cam assembly  28 . As shown in  FIGS. 1 and 2 , cam assembly  28  comprises a support frame  29  fixed by bolts to the main frame  30  of the apparatus of  FIG. 1 . The view of assembly  28  in  FIG. 1  is obtained by removing lid  29 ′ from the joining surface  29 ″ (see  FIG. 2 ). 
         [0045]    With reference to assembly  28 , the input shaft  27  is assembled on bearings  31 , which in turn are assembled on frame  29 . Conjugated cams&#39;  32  and  33  are assembled on input shaft  27  of assembly  28 . Rollers  32 ′ and  33 ′, which are assembled on respective arms  32 ″ and  33 ″, are in rolling contact with surfaces of cams  32  and  33 , respectively. 
         [0046]    With reference to  FIG. 2 , arms  32 ″ and  33 ″ are assembled on exit shaft  35  of assembly  28 . The exit shaft  35  is assembled on bearings  36 , which are in turn assembled on frame  29 . 
         [0047]    With reference to  FIGS. 1 ,  3   a  and  3   b , an end of lever  38  of lever mechanism  37  is fixed to arm  39 , which in turn is assembled on exit shaft  35  of assembly  28 . Fixing of lever  38  to arm  39  can be accomplished by means of a flange connection using bolts  40 , as shown in  FIGS. 3   a  and  3   b.    
         [0048]    Lever  38  is connected to lever  41  by means of the moveable hinge  42 . Hinge  42  comprises a slide  43  assembled to rotate on the end of lever  38 . Slide  43  is able to move in slot  44  of lever  41  during the rotations RO of lever  38  around axis  35 ′ caused by rotation of exit shaft  35  of assembly  28 , as shown in  FIGS. 3   a  and  3   b.    
         [0049]    The end of lever  41  is connected to gear wheel  46  of  FIG. 4  to rotate tube  14  in directions S and S′. The connection of lever  41  to gear wheel  46  is achieved by means of a flange using bolts  45 , as shown in  FIG. 4 . 
         [0050]    Rotation of cams  32  and  33  obtained by the rotation of shaft  20 , as is required to accomplish the winding cycles, obtains rotations S and S′ of arm  41  around axis  12 . Rotations S and S′ are synchronized with the translations in directions T and T′ of tubes  13  and  14 . 
         [0051]    Therefore, assembly  28  by having its own frame  29 , where bearings  31  and  36  of the shafts of cams  32  and  33  are supported, can be considered an independent unit that is assembled separately and then bolted to frame  30 , as shown in  FIG. 2 . This solution can facilitate manufacture and assembly of the apparatus of  FIG. 1 . 
         [0052]    As an alternative embodiment, frame  29  can be omitted. In this case, the bearings of shafts  27  and  35  can be assembled on needed supports of main frame  30 . 
         [0053]    The transmission formed with gear wheels  25  and  26  and the position of assembly  28  locates axis  27 ′ of input shaft  27  and all of assembly  28  near to base  30 ′ of the apparatus. In other words, axis  27 ′ has been displaced on the lower side of shaft  20 , whilst tubes  13  and  14  are located on the upper side of shaft  20 . In this way, the distance that separates axis  19  of shaft  20  from axis  12  has been reduced, therefore the distance that separates axis  12  from the base  30 ′ of the apparatus has been reduced. This has achieved that the apparatus of  FIG. 1  has a low height from base  30 ′ and the moments of force generated by the translation of inertias in directions T and T′ with respect to base  30 ′ have been reduced. Therefore, the speed of the apparatus as generated by motor  24  can be increased. At the same time, a higher speed of the synchronization of motor  60  with motor  24  has been increased. 
         [0054]    By substituting arm  39  with similar arms, which differently distance hinge  42  from exit shaft  35 , it is possible to change the angles of rotations S and S′ for winding cores having for example different pole widths. Bolt assembly  39 ′ of an arm  39  is necessary for the adjustment of the distance of hinge  42  because it is able to position the positioning head  39 ″ at different distances. Positioning head  39 ″ is received in a slot of an arm  39  (see  FIGS. 1 ,  3   a  and  3   b ) to position lever  38  with respect to the arm  39   
         [0055]    To adjust the distance which the needle  11  accomplishes in directions T and T′, in other words, to change the translation path of the needle, for example when the length of the poles of the cores changes, the inclination of arm  15  around pin  18  is modified, which requires modifying the inclination of ring  16 ′ with respect to shaft  20  by using assembly  58 . To achieve this, lever  50  is hinged at one the end to ring  16 ′ of assembly  16 , whilst the other end of lever  50  is hinged to sleeve  51 . Sleeve  51  can move when required (during adjustments) along shaft  20 , i.e. parallel to axis  19 . 
         [0056]    Cylinder  52  is threaded on the outside, and this thread of cylinder  52  engages the thread present inside gear ring  53 , as shown in  FIG. 1 . By rotating gear ring  53  around axis  19 , cylinder  52  translates parallel to axis  19  to displace sleeve  51  by means of the engagement connection  52 ′ of cylinder  52  inside the slot of  51 , as shown in  FIG. 1 . 
         [0057]    The key  54  existing between cylinder  52  and support  55  guarantees that cylinder  52  does not rotate, but only translates parallel to axis  19  when arm  15  needs to be inclined. Gear ring  53  can be rotated for predetermined angles by a pinion (not shown) which is rotated by motor  56  (see  FIG. 2 ). 
         [0058]    To adjust the path of the needles in directions R and R′ for the stratification, programming of motor  60  needs to be changed. The new programming needs to guarantee the synchronization with the translations and rotations generated by motor  24 . 
         [0059]      FIG. 5  shows an embodiment where levers  41  and  38  of the embodiment of  FIG. 3   a  have been substituted with a gear train  220 . More particularly, gear  200  is connected to gear wheel  46  of  FIG. 4  to rotate tube  14  in directions S and S′. The connection of gear  200  to gear wheel  46  is achieved by means of a flange abutment using bolts like  45  shown in  FIG. 4 . 
         [0060]    Gear  201  meshes with gear  200  as shown in  FIG. 5 . Gear  201  is free to rotate (idle) on shaft  202 , as is more fully explained with reference to  FIG. 6 . 
         [0061]    Gear  203  is fixed on the end of shaft  35  of cam assembly  28  by means of coupling  204 . 
         [0062]    Therefore, rotations of shaft  35  deriving from rotation of cams  32  and  33  are transmitted to gear wheel  46  through the gear train  220  consisting of gears  203 ,  201  and  200   
         [0063]    With reference to  FIG. 6 , collar  206 , lever  208  and the assembly of shaft  209  are shown. These parts and assembly are only partly shown in  FIG. 4  for reasons of clarity. 
         [0064]    More particularly only collar  206  is shown with dash line representation. 
         [0065]    Again with reference to  FIG. 6 , collar  206  is assembled to rotate on cylinder  205  of  FIG. 4  around axis  12 . Collar  206  is provided with extending portion  206 ′, where shaft  202  is fixed by means of a clamp connection closed by bolt  202 . In this way gear  201  is supported to rotate on shaft  202 , which is integral with collar  206 . 
         [0066]    Lever  208  is hinged to portion  206 ′ and to the end of shaft  209 , as shown in  FIG. 6 . Head  209 ′ of shaft  209  is clamped between cylinder  210  and  211  by means of bolts  212  which are threaded into frame  30 , as shown in  FIG. 6 . By substituting cylinder  210  with other cylinders having a different length L from abutment surface  30   a  of frame  30 , the position of gear wheel  201  can be changed, as shown by the examples of the two positions in dash line  201 ′ and  201 ″. 
         [0067]    The position of gear wheel  201  can be changed when substituting gear wheel  203  with other gear wheels for achieving different gear ratios (see dash line representation of substituted gears  35   a  and  35   b ), as is required to change to angles of rotation in directions S and S′.

Technology Classification (CPC): 7