Patent Document

BACKGROUND OF INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The invention concerns alternators in general, including for automobiles.  
         [0003]     More specifically, the invention concerns an alternator, particularly for an automobile, that includes a stator equipped with a cylindrical body that has several phases; each phase includes, first, an intake and an outtake located at least in part on the exterior of the stator body and, second, electric conducting elements that cross the body of the stator to form the first and second chignons from the two axial sides opposite the stator; the conducting elements are electrically connected to each other to form at least one winding that connects the phase inputs to the phase outputs, and the inputs are composed of bars that have at least one longitudinal flat surface extending along at least a part of the bar and each input contains a first segment that crosses the body of the stator and a second end segment that extends from the axial side of this body; the second segments of the inputs are located on the same axial side of the stator body and are electrically connected to form a neutral point.  
         [0004]     2. Background Art  
         [0005]     Devices of this type are known from previous technology, primarily through the French patent application 0116658, which will be published under number FR-A-2 818 822 in the name of VALEO, which shows an alternator, the neutral point of which can be made by arranging the phase inputs in different ways. The inputs are rectangular bars, that present opposite, relatively wide, longitudinal flat surfaces that are called flats and opposing, relatively narrow longitudinal flat surfaces called edges.  
         [0006]     The body of the stator includes narrow, radial notches, and the input bars are engaged in these notches so that the flats of the first segments each extend into a significantly radial plane.  
         [0007]     The inputs are formed so that their second segments present the form of portions of coaxial cylinders in the body of the rotor. The flats constitute the axial surfaces of these cylinder portions, and the edges are the interior and exterior radial surfaces. Thus, the second segments are obtained by laterally bending the first segments, i.e. on the side of either of the flats.  
         [0008]     The inputs are in contact with each other or with the neutral bar through the flats of their second segments. The neutral bar and the second segments of the inputs are thus stacked axially.  
         [0009]     This arrangement offers a defect because if it is very difficult to weld the inputs between them or on the neutral bar after bending the electrically conducting elements, because there is not enough space available to introduce the welding head axially.  
         [0010]     Patent documents EP 1 143 596 and U.S. Pat. No. 5,998,903 reveal alternators that containing stators the three inputs of which are combined at one neutral point. A first input includes a second axial end segment; the flats of this second segment extend into radial planes. The second segments of the other two inputs have, as in French patent application 01 16658, the form of coaxial cylinder portions in the body of the rotor. The flats constitute the axial surfaces of these cylinder portions, and the edges constitute the interior and exterior radial surfaces. These cylinder portions each extend through an axial part; these axial parts are placed through a flat onto the two flats opposite the second segment of the first input.  
         [0011]     This arrangement allows welding the inputs to each other after bending the pins, but presents the defect of increasing the axial size of the chignon carrying the inputs.  
       SUMMARY OF INVENTION  
       [0012]     In this context, the purpose of the present invention is to correct the defects cited above, and to propose several arrangements that allow welding the inputs after bending the pins, without having to systematically use the parts with an axial orientation.  
         [0013]     For this purpose, the device in the invention, which also complies with the generic definition given in the introduction above, is essentially characterized by the fact that the inputs are twisted, with the flat surface of each input extending along the first segment in a generally radial plane and extending along the second end segment either to form a coaxial cylinder portion in the body of the stator, or in a plane tangential to a coaxial cylinder in the body of the stator.  
         [0014]     Thanks to the twisting of the invention, it is possible to weld the inputs easily and economically after bending the electrical conducting elements, with a chignon with smaller axial dimensions.  
         [0015]     To reduce the number of parts, in one possible method of fabricating the invention, the second segments of the inputs are identical.  
         [0016]     Advantageously, the second segments of the inputs are electrically connected through a neutral bar with a circumferential orientation; the second segments of the inputs are mounted on this neutral bar through their respective flat surfaces.  
         [0017]     Preferably the second segments of the inputs have a circumferential orientation with their respective flat sides forming portions of coaxial cylinders in the body of the stator.  
         [0000]     For example, the second segments of the inputs extend along an axial direction, with their respective flat surfaces extending in planes that are tangent to the neutral bar.  
         [0018]     Advantageously, a first input includes a second, relatively long segment, with a circumferential orientation, with two other inputs containing second segments of the same length that are relatively shorter than the length of the second segment of the first input; the flat side of the second segment of the first input forms a coaxial cylinder portion in the body of the stator and the second segments of the two other inputs are mounted by their respective flat sides on the flat side of the second segment of the first input.  
         [0019]     Preferably, the second segments of the other two inputs are circumferential in orientation and extend in the same direction, clockwise or counter-clockwise, and their respective flat surfaces form coaxial cylinder portions in the body of the stator.  
         [0020]     For example, the second segments of the other two inputs are circumferential in orientation and extend in opposite directions—clockwise for one and counter-clockwise for the other—with their respective flat surfaces forming coaxial cylinder portions in the body of the stator.  
         [0021]     Advantageously, two inputs are united through their respective second segments to form the two branches of a pin; these respective second segments are circumferential in orientation, with the respective flat surfaces of these two second segments arranged in the extension of each other and form a coaxial cylinder portion in the body of the stator; a third input is attached through the flat side of its second segment to said cylinder portion.  
         [0022]     Preferably, the inputs are located at different angle positions around the shaft of the body of the rotor; the two inputs united in a pin are consecutive, following the circumference of the body of the stator.  
         [0023]     For example, the inputs are located at different angle positions around the shaft of the body of the rotor; the two inputs united in a pin are not consecutive, following the circumference of the body of the stator.  
         [0024]     Advantageously, the second segment of the third input is circumferential in orientation with its flat side forming a coaxial cylinder portion in the body of the stator.  
         [0025]     Preferably, the second segment of the third input extends along an axial direction, with the flat surface extending into a plane that is tangent to the second segments united with the two inputs forming a pin.  
         [0026]     For example, the second segments of the inputs are circumferential in orientation and all extend in parallel over at least a part of their length.  
         [0027]     Advantageously, the second segments of the inputs all extend in the same direction—clockwise or counter-clockwise.  
         [0028]     Preferably, the respective second segments of at least two inputs extend in opposite directions, clockwise for one and counter-clockwise for the other.  
         [0029]     For example, at least one of the inputs includes an axial segment that extends its second segment in a direction opposite the body of the stator.  
         [0030]     Advantageously, the second segments of the inputs are located at an axial end of the first or second chignon. 
     
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0031]     Other properties and advantages of the invention will clearly result from the description given above, which is indicative and not limiting, in reference to the attached figures, which include.  
         [0032]      FIG. 1  is an axial half-section view of an alternator according to the invention.  
         [0033]      FIG. 2   a  is a top view of a part of the body of a stator from  FIG. 1  according to a first method of fabricating the invention;  FIG. 2   b  is a section view of half of a stator according to the arrows IIb of  FIG. 2   a ; and  FIG. 2   c  is a side view according to arrow IIc of  FIG. 2   a.    
         [0034]      FIG. 3  is a similar view to  FIG. 2   b , for a variant of the first method for fabricating the invention.  
         [0035]      FIGS. 4   a  and  4   b  are views similar to views  2   a  and  2   b , for another variant of the first mode for fabricating the invention.  
         [0036]      FIG. 5  is a view similar to  FIG. 2   b , for another variant of the first method for fabricating the invention.  
         [0037]      FIGS. 6   a  and  6   b  are views similar to views  2   a  and  2   b , for another variant of the first method of making the invention.  
         [0038]      FIG. 7  is a partial view similar to  FIG. 2   a  for another variant of the first method of making the invention.  
         [0039]      FIGS. 8   a  and  8   b  are views similar to views  2   a  and  2   b  for a second method of making the invention  
         [0040]      FIG. 9  is a view similar to  FIG. 8   b  for a variant of the second method of fabricating the invention.  
         [0041]      FIGS. 10   a  and  10   b  are views similar to  2   a  and  2   b , for a third method for designing the invention.  
         [0042]      FIGS. 11   a  and  11   b  are views similar to views  10   a  and  10   b , for a variant of the third method for fabricating the invention.  
         [0043]      FIGS. 12   a ,  12   b  and  12   c  are views similar to views  2   a ,  2   b  and  2   c  for a fourth method of constructing the invention.  
         [0044]      FIG. 13  is a view similar to  FIG. 12   b  for a variant of the fourth method of constructing the invention.  
         [0045]      FIGS. 14   a  and  14   b  are views similar to views  12   a  and  12   b , for another variant of the fourth method for designing the invention. 
     
    
       [0046]     In the figures, identical or similar elements will be assigned the same reference signs.  
       DETAILED DESCRIPTION  
       [0047]      FIG. 1  represents a polyphased turning electrical machine in the form of a compact alternator with internal ventilation of the triphased type for an internal-combustion automobile.  
         [0048]     The alternator contains, from left to right in  FIG. 1 , i.e. from front to back, a drive pulley  1  joined (here, through a nut) to the front end of a shaft  2 , the rear end of which holds slip rings (not referenced) that belong to a slip ring assembly  3 . The axis of shaft  2  is the axis of rotation of the machine.  
         [0049]     In the center, the shaft  2  carries for mounting the rotor  4  equipped with an excitation winding  5 , the ends of which are connected through wire links to the slip ring assembly  3 . The rotor  4  here is a rotor with fittings and thus contains two front and back polar wheels  6 ,  7  each carrying a front fan  8  and rear fan  9  for, in a given axial space, an increase in the power of the alternator and a reduction in alternator noise. Each wheel  6 ,  7  is attached to shaft  2  equipped with sections trimmed for this purpose, as shown in  FIG. 1 . Each wheel contains a flange perpendicular to the axis of the shaft  2 . The excitation winding  5  is located axially between the flanges of the two wheels  6 ,  7  arranged to form a cylindrical core for mounting the winding  5 . On the outside circumference of the flanges are arranged teeth that extend axially. The teeth are trapezoidal in shape and have chamfers on the sides. The teeth of one of the wheels are directed toward the other wheel, angled in relation to the teeth of this other wheel. Thus, the teeth are embedded so that, in one design variant, permanent magnets are intercalated between the two to again increase the power of the machine. For example, profiled grooves are arranged in the lateral edges of the teeth to receive the permanent magnets as described in document FR-A-2 748 248. When the winding  5  is activated, the rotor  4  is magnetized, and thus a pair of magnetic poles is defined, with each polar wheel containing respectively P/2 north poles and P/2 south poles. For more information, refer to document EP-A-0 515 259. The teeth of the polar wheels present laterally, at the level of their roots, to the flange of the polar wheel in question (each one) at least one anti-noise chamfer to again reduce the noise, particularly magnetic noise, of the alternator. Advantageously, each tooth presents, in relation to an axial symmetry axis, two anti-noise chamfers. Thus, the alternator is less noisy.  
         [0050]     Fans  8 ,  9  contain a first series of blades, which create ventilation channels between them. Advantageously, two series of blades of different lengths are provided as described in document FR-A-2 811 156. Thus, at least one blade from the second series of blades is inserted between two longer consecutive blades from the first series of blades. This arrangement reduces the noise of the alternator, while improving its ventilation. The blades come out from a flange, by sectioning and bending, which is mounted (for example, by welding or any other means, such as crimping), on the polar wheel  6 ,  7  in question. Each wheel has, as described, axial teeth directed toward the other wheel, with embedding of the teeth from one wheel to the next to form magnetic poles when the winding  5  is activated, thanks to the slip rings of the slip ring assembly  3 , each in contact with a brush (not referenced) carried by a brush holder  10  also used as a support for a voltage regulator (not visible) connected electrically to the brushes to regulate the voltage of winding  5 .  
         [0051]     The regulator is connected to a current rectifying device  11 , such as a diode axle (two of which are visible in  FIG. 1 ), which is itself connected to the phase outputs equipped with windings, included in the stator  13  of the alternator. The axle here is the type described in document EP-A-0 743 738. Refer to this document for more information. This axle includes a positive heat shunt on which the positive diodes are mounted, a negative heat shunt on which the negative diodes are mounted, and a connector. Here, the negative shunt is formed by the flange of the rear main bearing  16  of the alternator described below. As a variant, the axle is the type described in document FR 01 09 482 filed Jul. 16, 2001. In this case, the positive shunt includes cooling fins, which extend in the radial direction of the alternator; the negative diodes carried by the rear main bearings are cooled by convection and conduction. This type of axle is well adapted to the high-power alternator in the invention. The stator  13 , forming an induced circuit, surrounds the rotor  4  and has a body  14  with axial notches inside for the passage of the wires or pins that the windings contain. It is known that the body  14  consists here of a packet of plates, each with notches. These radial, oblong notches constitute grooves when the plates are aligned and lead to the internal circumference of the body  14 , and are semi-closed. The body  14  surrounds the rotor  4  with the presence of a radial air gap between the internal circumference of the body  14  and the external circumference of the rotor  4 .  
         [0052]     The windings are arranged to form chignons  12 ,  12 ′ which extend, first, out on either side of the body  14  and, second, radially above the fans  8 ,  9 .  
         [0053]     These fans  8 ,  9  extend close to a front main bearing  15  and a rear main bearing  16  respectively. Bearings  15 ,  16  are metal, and aluminum based. These bearings include, as known, tabs for mounting the alternator on a fixed portion of the automobile and electrical connection of the alternator to the ground. The main bearings  15 ,  16  are perforated for internal ventilation of the alternator through fans  8 ,  9  when the assembly of fans  8 ,  9 , rotor  4 , shaft  2  is rotated by pulley  1  connected to the automobile engine through a transmission device that includes at least one belt engaged with pulley  1 . This ventilation cools the windings of the chignons  12 ,  12 ′ and the winding  5 , as well as the brush-holder  10  with its voltage regulator and the rectifying device  11 . We have shown on  FIG. 1  with arrows the path followed by the cooling fluid, in this case air, through the various openings of main bearings  15 ,  16  and within the machine. Each bearing has a sunken shape and has a flange (here with a transversal orientation) presenting air intake openings and, at the outside circumference of the flange, a axial annular edge with air outlet openings located above chignons  12 ,  12 ′.  
         [0054]     This device  11 , the brush-holder, as well as a perforated protective cap (not referenced) preferably made of plastic, are mounted through the rear main bearing  16  so that the rear fan  9  is more powerful than front fan  8 . As known in the industry, bearings  15 ,  16  are connected, here using screws or, in a variant, using non-visible rods, to form a crankcase or support intended to be mounted on a fixed part of the vehicle. This support carries the body  14 .  
         [0055]     Bearings  15 ,  16  each carry in the center for their flange a ball bearing  17 ,  18  to support, in rotation, the front and rear ends of shaft  2  crossing the main bearings to carry pulley  1  and the slip rings of the slip ring assembly  3 . The air intake openings are delimited by a cylindrical core with an axial orientation that forms a housing for mounting the ball bearing in question.  
         [0056]     The blades of fans  8 ,  9  extend radially above the housings presented by the main bearings  15 ,  16  for mounting the ball bearings  17  and  18 , which are ventilated in this way. In a variant, the alternator is cooled by a cooling liquid such as the cooling water from the internal combustion engine of the automobile; the rear main bearing containing channels as described, for example, in document DE-A-100 19 914 to be consulted for further explanations. The stator in this case is mounted using pads of an elastic material, an elastomer for example, on the crankcase to filter the vibrations and reduce noise. This is also the case in  FIG. 1 , where the square-section pads are not referenced.  
         [0057]     These pads are between the free ends of the outside part in the form of a lip with axial orientation of the main bearings and the axial ends facing the body  14 . These pads constitute elastic damping equipment with radial and axial action for mechanical decoupling of the body  14  from the stator in relation to the crankcase formed by main bearings  15 ,  16 . As a variant, the elastic damping means are at the level of the notches  141  between the edges of the notches and the electrically conducting elements, described below, which are mounted in the notches as described in document FR 99 16369 filed on Dec. 23, 1999 and published under number FR-A-2 803 126. In a variant, deformable thermoconducting resin is placed radially between the outside circumference of the body  14  and the internal circumference of one of the main bearings, such as the front bearing, as described in document FR 00 13527 filed on Oct. 6, 2000. In this case, the winding  5  of the rotor  4  can be formed from a conducting element wound and covered with a connection layer, for example of the thermohardening type, as described in document FR-A-2 809 546. The winding  5  releases more heat which is removed by the thermoconducting resin. In a variant, the body  14  is mounted directly on the main bearings.  
         [0058]     In a variant, the rotor contains projecting poles as described in document FR 01 00122 filed on Jan. 5, 2001; permanent magnets are inserted in housings made in the packet of plates contained in the rotor. These housings are open to the external circumference of the rotor and closed axially by magnetic parts intended to stop against the magnets.  
         [0059]     In FIGS.  2  to  14 , the alternator is at least the triphased type, and contains at least three phases with, for each phase, an input E 1  to E 12  and an output S 1  to S 3  respectively. The outputs, as known in the industry, are connected to the electric current rectifying device  11  and the phases of the stator  13  produce alternating current when the rotor is excited and is driven in rotation by the engine of the vehicle via pulley  1 . For this reason, the alternative current must be rectified to supply direct current to the electric consumers of the vehicle and recharge the battery of the vehicle. The phases are mounted in a star or a Y so that the inputs are connected to a neutral point as known in the industry.  
         [0060]     The alternator may also be hexaphased and thus include, in addition to the first series of three phases, a second series of three phases with an input and an output for each phase, These outputs are connected as described above to the rectifier  11 , as described in document EP-A-0 743 738 cited above; the connector of device  11  has tabs for mounting outputs belonging to a network of electrically conducting lugs. The mounting of the outputs on the tabs is done, for example, by crimping or welding.  
         [0061]     In all cases, the alternator includes a stator  13 , which has a cylindrical body  14  with several phases. The body  14  includes the notches  141  that cross it parallel to its axis; these notches  141  end on an interior surface of the body  14  and are regularly distributed along the interior circumference of the body  14 .  
         [0062]     As specified above, the stator includes at least three phases in the design modes of the invention described here. Each phase includes, first, an input E 1  to E 12  and one output S 1  to S 3  located at least in part on the exterior of the body  14  of the stator  13  and, second, of the electrically conducting elements  50  crossing the body  14  of the stator  13  to form, from the two axial sides opposite the stator, the first and second chignons  12  and  12 ′.  
         [0063]     The conducting elements  50  are electrically connected to form at least one winding that connect the phase inputs E 1  to E 12  to the phase outputs. There is generally one winding per phase.  
         [0064]     These electrically conducting elements  50  are pins containing two straight and parallel axial branches  51  and a head  52  in the form of an arch and connected by two opposite ends to the two axial branches  51 .  
         [0065]     The axial branches  51  of the same conducting elements are engaged in different notches  141  of the body  14  of the stator  13 , with one branch  51  located toward the outside of the body  14  and the other located toward the inside of the body  14 . In addition, each axial branch  51  extends from the side opposite the head  52  through a connection part  511  that is welded onto a connection part belonging to the axial branch of another pin  50 . Here, the branches  51  are rectangular in shape. Thus, when the alternator is the triphase type, two axial branches  51  are provided per notch  141  as shown in  FIG. 5  of Document FR-A-2 818 821. In a variant, as shown in  FIG. 9  of Document FR-A-2 818 821, four branches  51  are provided by notch  141 , and the phases are mounted in a star or a Y as shown on  FIG. 7  of this document. The branches  51  are advantageously mounted with a radial overlay in each notch  141 ; here it is oblong in shape with a radial orientation.  
         [0066]     The arched heads  52  of the pins  50  all project from the same axial side of the body  14  of the stator  13  and form the first chignon  12 . They are all parallel to each other and each has in the center an axial top  521  located on the side opposite the body  14 . These axial tops  521  make a circle around the axis of the body  14  and form the axial end of the first chignon  12 .  
         [0067]     The connection parts  511  of the pins  50  project from the axial side of the body  14  of the stator  13  opposite the first chignon  12  and form the second chignon  12 ′.  
         [0068]     Inputs E 1  to E 12  are formed of bars that have at least one longitudinal flat side  21  to  24  and extend along at least one part of the bar, and generally over the whole bar. Inputs E 1  to E 12  and outputs S 1  to S 3  advantageously have the same section as the bars  51  and are, therefore, rectangular here.  
         [0069]     More specifically, inputs E 1  to E 3  are generally rectangular-shaped bars, and thus have two opposite flat sides  12  to  24  that are relatively wide, called flats, and two narrow surfaces  21 ′ to  24 ′, which are flat and opposite, and are called edges, which are relatively narrower than the flat surfaces  21  to  24 .  
         [0070]     Each input E 1  to E 12  contains a first segment  25  that crosses the body  14  of the stator  13  and a second end segment  26 - 40  that extends from one axial side of this body  14 ; the second segments  26 - 40  of the inputs E 1  to E 12  are located on the same axial side of the body  14  of the stator  13  and are electrically connected to form a neutral point  53 .  
         [0071]     Each input E 1  to E 12  also includes a third segment  45  connecting the first and second segments, and a fourth segment  46  that extends the first segment  25  from the side opposite the third segment  45 . This fourth segment  46  projects from the axial side of the body  14  of the stator  13  opposite the neutral point  53  and is welded to an electrically conducting element  50  of the phase associated with said input.  
         [0072]     According to the invention, inputs E 1  to E 12  are twisted, with at least one flat surface  21 - 24  of each input, and generally both, extending along the first segment  25  in a radial plane and extending along the second end segment  26 - 40 , either to form a coaxial cylinder portion in the body  14  of stator  13 , or in a plane at a tangent to a coaxial cylinder in the body  14  of stator  13 .  
         [0073]     In the first case, the second segments are circumferential in orientation. In the second case, the second segments are axial in orientation.  
         [0074]     The second segments  26 - 40  of the inputs E 1  to E 12  are, in both cases, located at an axial end of the first or second chignon  12  or  12 ′. In the design methods shown on FIGS.  2  to  14 , these second segments  21  to  24  extend more specifically along the circle drawn by the tops  521  of the arched heads  52 .  
         [0075]     The orientation of the flat surfaces  21  to  24  is changed progressively along the third segment  45  of each input, which connects the first segment  25  to the second segment.  
         [0076]     In the first design mode for the invention, shown on FIGS.  2  to  7 , at least two of the second segments  26  of inputs E 1  to E 3  are identical.  
         [0077]     In a first design variant shown on  FIGS. 2   a  to  2   c , the second segments  26  of the three inputs E 1  to E 3  have a circumferential orientation and extend in the same direction, which is clockwise on  FIG. 2   a . The second segments  26  of inputs E 1  and E 2  have the same circumference length, greater than the length of the second segment  26  of input E 3 .  
         [0078]     Input E 2  is arranged between inputs E 1  and E 3  following the circumference of the body  14 , and inputs E 1  and E 2  are separated by the same angular offset as inputs E 2  and E 3 .  
         [0079]     The second segment of input E 1  is located slightly more to the outside of the body  14  than the second segment of input E 2 , which is itself located slightly more to the outside of the body  14  than the second segment of input E 3 .  
         [0080]     If we call the parts of the second segment  26 , located relatively close to the third segment  45  and opposite the segment, the anterior part and the end part  261  and  262 , we will see on  FIG. 2   a  that the end part  262  of the second segment  26  of input E 1  is plated along the anterior part  261  of the second segment  26  of input E 2 . Likewise, the end part  262  of the second segment  26  of input E 2  is plated along the anterior part  261  of the second segment  26  of input E 3 . The second segments of inputs E 1  and E 3  do not join.  
         [0081]     The second segments of inputs E 1  to E 3  are plates on each other through their relatively wide flat surfaces  21 .  
         [0082]     The second segment  26  of input E 1  is welded through a free end  263  on the second segment  26  of input E 2  at a relatively central point of the segment.  
         [0083]     The second segment  26  of input E 2  is welded through its free end  263  onto the free end  263  of the second segment  26  of input E 3 .  
         [0084]     Thus, the second segment  26  of input E 3  does not extend in the clockwise direction beyond the weld point with input E 2 .  
         [0085]     In a second variant, the second segment  26  of input E 3  extends in the clockwise direction beyond the weld point with input E 2  as shown on  FIG. 3 .  
         [0086]     In a third design variant, shown on  FIG. 3 , the second segment  26  of input E 2  extends beyond the weld point with input E 2  also through an axial segment  56  of the side opposite the third segment  45 ; this axial segment  56  extends in a direction opposite the body  14  of the stator  13 . In these three variants, three inputs and two welds are used. In a variant, three welds and an additional neutral bar are used to reduce the circumference length of the inputs.  
         [0087]     Thus, in a fourth design variant, shown on  FIGS. 4   a  and  4   b , the second segments  27  of inputs E 1  to E 3  are electrically connected by a neutral bar  54  with a circumferential orientation; the second segments  27  of the inputs are attached to this neutral bar through their respective flat surfaces  21 .  
         [0088]     This neutral bar  54  has a rectangular section identical to the section of inputs E 1  to E 3  and thus also includes two opposite flat surfaces  21 .  
         [0089]     The neutral bar  54  is arranged so that its flat surfaces  21  form coaxial cylinder portions in the body  14 .  
         [0090]     The second segments  27  of inputs E 1  to E 3  also have a circumferential orientation, and their respective flat surfaces  21  form coaxial cylinder portions in the body of the stator; the second segments  27  of the three inputs E 1  to E 3  are plated along the flat surface  21  of the most radially interior neutral bar  54 .  
         [0091]     These second segments  27  are welded by free ends  271  on the neutral bar  54 .  
         [0092]     The second segments  27  of inputs E 1  to E 3  are here the same circumference length and are, therefore, identical. This is also true in FIGS.  4  to  7 .  
         [0093]     The second segments  27  are arranged so that they extend from each other, parallel to the neutral bar  54 , but do not touch. The neutral bar  54  practically does not exceed each side of the three aligned second segments  27 .  
         [0094]     Inputs E 1 , E 2  and E 3  are spaced regularly around the axis of the body  14 . In a variant, at least one of the second segments  27  is a different circumference length.  
         [0095]     A fifth design variant is shown on  FIG. 5 . It is identical to the fourth design variant in all points, with the exception of the neutral bar  54 , which extends to one of its ends  541  through a segment with an axial orientation  56  that extends in a direction opposite the body  14  of the stator  13 .  
         [0096]     A sixth design variant is shown on  FIGS. 6   a  and  6   b . It is identical to the fifth design variant with the exception of the fact that the second segments  27  of inputs E 1  to E 3  extend in an axial direction and not in a circumferential direction, and their respective flat surfaces  21  extend in planes tangent to the neutral bar  54 . Thus, the circumferential lengths of the inputs are reduced.  
         [0097]     The second segments  27  of inputs E 1  to E 3  can be attached by their respective flat surfaces onto the flat surface  21  of the neutral bar  54  located radially farthest inside the body  14 , as in  FIG. 6   a , or farthest to the outside of the body  14  as in  FIG. 7 .  
         [0098]     Thus, this first design method is particularly simple, since the three inputs are of the same type because they extend in the same circumferential direction, and at least two are identical, except in the variants where one of the inputs extends through an axial segment. Thus, it is possible to limit the number of different parts used, which is practical and economical.  
         [0099]     A second design method for the invention is shown on  FIGS. 8 and 9 . In this method, two welds are used along with a first input with a very large circumference. Thus, a first input E 4  includes a relatively long second segment  28  with a circumferential orientation; two other inputs E 5  and E 6  have two second segments  29  with the same length, which is shorter than the length of the second segment  28  of the first input E 4 .  
         [0100]     The two flat surfaces  22  of the second segment  28  of the first input E 4  form portions of coaxial cylinders in the body  14  of the stator  13 ; the second segments  29  of the other two inputs E 5  and E 6  are attached through their flat surfaces  22  on one of the two flat surfaces  22  of the second segment  28  of the first input E 4 .  
         [0101]     The other inputs E 5  and E 6  are arranged on the same side of the first input E 4 , along the circumference of the body  14  and the second segment  28  of the first input E 4  extends in the direction of these inputs E 5  and E 6 .  
         [0102]     In the first design variant shown on  FIGS. 8   a  and  8   b , the second segments  30  and  31  of the other two inputs E 5  and E 6  are circumferential in orientation and extend in opposite directions—clockwise for one and counterclockwise for the other following the circumference of the body  14  of the stator  13 .  
         [0103]     The respective flat surfaces  22  of the second segments  30  and  31  of the other two inputs E 5  and E 6  form coaxial cylinder portions in the body  14  of the stator  13 . These flat surfaces  22  extend parallel to one of the two flat surfaces  22  of the second segment  28  of the first input E 4  over the entire length, or at least through an end part  221 , and are plated against said flat surface  22  of the second segment  28 .  
         [0104]     The second segments  30  and  31  of the other two inputs E 5  and E 6  are welded through the free ends  301  and  311  to the second segment  28  of the first input E 4 .  
         [0105]     One variant, which is not shown, is identical to the first, with the exception of the fact that the second segments  30  and  31  belonging respectively to inputs E 5  and E 6  extend in the same direction. This direction may be identical to the direction in which the second segment  28  of the first input E 4  extends, or in the opposite direction. Their respective flat surfaces  22  form coaxial cylinder portions in this body  14 .  
         [0106]     A third variant is identical to the first or the second variant, but the second segment  28  of the first input E 4  extends through an axial segment  56  that extends in a direction opposite the body  14  from the end of the second segment  28  opposite the third segment  45 . It is shown on  FIG. 9 .  
         [0107]     Of course, it is possible to reduce the number of welds and simplify the inputs.  
         [0108]     Thus, in a third design of the invention, shown on  FIGS. 10 and 11 , two of the inputs E 7  and E 8  are united through their second segments  32  and  33  to form the two branches of a pin  55 .  
         [0109]     These second segments  32  and  33  are circumferential in orientation and extend in opposite directions—one clockwise and the other counterclockwise-following the circumference of the body  14 . Their respective flat surfaces  23  are arranged so that they extend from each other. These flat surfaces  23  together form a continuous portion of coaxial cable in the body  14  of the stator  13  so that the inputs E 7  and E 8  are simplified.  
         [0110]     A third input E 9  is attached through the flat surface  23  of its second segment  34 / 35  to said cylinder portion formed by the flat sides  23  of the second segments  32  and  33  of inputs E 7  and E 8 .  
         [0111]     In a first design variant, shown on  FIGS. 10   a  and  10   b , inputs E 7  to E 9  are located at different angle positions around the axis of the body  14  of the rotor  13 , and the two inputs E 7  and E 8  combined in a pin are consecutive and follow the circumference of the body of the stator. Here, input E 9  has a longer circumference length than that of inputs E 7 , E 8  combined.  
         [0112]     The second segment  34  of the third input E 9  is circumferential in orientation and its opposite flat surfaces  23  form portions of coaxial cylinders in the body  14  of the stator  13 .  
         [0113]     This second segment  34  includes an end part  341  that extends in parallel to the united second segments  32  and  33  of inputs E 7  and E 8 , and is attached by one of the two flat surfaces  23  onto one of the two opposite flat surfaces  23  of the combined second segments  32  and  33 .  
         [0114]     The end part  341  of the second segment  34  is welded at one point onto the combined second segments  32  and  33 , for example through a free end  342 .  
         [0115]     A second design variant is shown on  FIGS. 11   a  and  11   b . It is identical to the first variant, with the exception of the following points.  
         [0116]     We see first that the two inputs E 7  and E 8  combined in a pin are not consecutive following the circumference of the body  14  of the stator  13 . The third input E 9  is set between inputs E 7  and E 8 .  
         [0117]     We also note that the second segment  35  of the third input E 9  extends in an axial direction, with one of its opposite flat sides  23  extending into a plane at a tangent with the combined second segments  32  and  33  of the two inputs E 7  and E  8  forming a pin.  
         [0118]     This second segment  35  is welded at one point on the combined second segments  32  and  33 , for example through a free end  351 .  
         [0119]     A third variant is identical to the first or second variant, but the second segment  34 / 35  of the third input E 9  extends through an axial segment  56  that extends in a direction opposite the body  14  from the end of the second segment  34 / 35  opposite the third segment  45 .  
         [0120]     It should be noted that the characteristics of the first and second variants can be combined without moving away from the invention. Thus, one can combine the consecutive inputs E 7  and E 8  with a third input E 9 , the second segment of which has an axial orientation. Likewise, one can combine non-consecutive inputs E 7  and E 8  with a third input E 9 , the second segment of which has a circumference orientation.  
         [0121]     In a fourth design method for the invention shown on FIGS.  12  to  14 , the second segments  36  to  40  of inputs E 10  to E 12  are oriented toward the circumference and all extend in parallel over at least a portion of their length. In this design, there is only one welding points for the three inputs.  
         [0122]     In a first design variant shown on  FIGS. 12   a ,  12   b  and  12   c , the second segments  36  to  38 , which belong respectively to inputs E 10  to E 12 , all extend in the same direction, for example clockwise following the circumference of the body  14  of the stator  13  shown on  FIG. 12   a.    
         [0123]     Inputs E 10  to E 12  are located at different angles around the axis of the body  14 . E 10  precedes E 11 , which precedes E 12  following the circumference of the body  14  on  FIG. 12   a  in a clockwise direction.  
         [0124]     The length of the second segment  36  is greater than the length of the second segment  37 , which is greater than the length of the second segment  38 ; the respective free ends  361 ,  371  and  381  of these three segments arrive at the same point.  
         [0125]     The respective flat surfaces  24  of second segments  36  to  38  form coaxial cylinder portions in the body  14  of the stator  13 .  
         [0126]     The second segment  38  of input E 12  is attached over its entire length, through one of its flat surfaces  24 , onto one of the flat surfaces  24  of the second segment  37  of input E 11 .  
         [0127]     Likewise, the second segment  37  of input E 11  is attached over its entire length, through its flat surface  24  opposite second segment  38 , onto one of the flat surfaces  24  of second segment  36  of input E 10 .  
         [0128]     The free ends  361  to  381  of second segments  36  to  38  are welded together.  
         [0129]     In a second design variant, shown on  FIGS. 14   a  and  14   b , the respective second segments of at least two of the inputs E 10  to E 12  extend in opposite directions, for example clockwise for the second segments  36  and  39  of inputs E 10  and E 11  and counterclockwise for second segment  40  of input E 12 , following the circumference of the body  14  shown on  FIG. 14   a.    
         [0130]     Inputs E 10  to E 12  are located at different angles around the axis of the body  14 , with E 10  preceding E 11 , which precedes E 12  following the circumference of the body  14  on  FIG. 14   a.    
         [0131]     The length of the second segment  36  of input E 10  is greater than the length of the second segment  39  of input E 11 . The respective free ends  361 ,  391  and  401  of the three segments  36 ,  39  and  40  arrive at the same point.  
         [0132]     The respective flat surfaces  24  of second segments  36 ,  39  and  40  form coaxial cylinder portions in the body  14  of the stator  13 .  
         [0133]     The second segment  39  of input E 11  is attached over its entire length, through one of its flat surfaces  24 , onto one of the flat surfaces  24  of the second segment  36  of input E 10 .  
         [0134]     In contrast, the second segment  40  of input E 12  is only attached, through the surface  24  of its free end  401 , onto the flat surface  24  of the second segment  36  of input E 10  opposite the second segment  39 .  
         [0135]     The free ends  361 ,  391  and  401  of second segments  36 ,  39  and  40  are welded together.  
         [0136]     A third design variant is identical in all points to the first and second design variants, with the exception of the fact that the second segment  36  of input E 10  extends through an axial segment  56  that continues in a direction opposite from the body  14  from the end of the second segment  36  opposite the third segment  45 . An example of this third variant is shown on  FIG. 13 .  
         [0137]     We see, therefore, that the different design methods of the invention described above allow easy welding of the second segments of the three inputs to each other; the welding head is positioned radially in relation to the body of the stator. In effect, the flat surfaces, which are relatively wide here, i.e. the flats, of the second segments always extend in planes perpendicular to a radial direction in relation to the cylindrical body of the stator.  
         [0138]     The invention has been described in an application to a triphased stator, but can be applied to a stator with six phases or more.  
         [0139]     The inputs can have non-rectangular sections, provided that each input has at least one flat longitudinal surface.  
         [0140]     We will note that the neutral point is formed by completing a small number of welds, from 1 to 3 depending on the design methods and variants.  
         [0141]     In the illustrated figures, in reality, four conducting elements are provided through axial notches  141  and two series of triphased windings offset by an electric angle of 30° as shown, for example, in  FIGS. 3 and 4  of document FR-A-2 819 117 filed on Oct. 19, 2001. The heads of the pins connect the axial branches as, for example, in  FIGS. 7, 15  and  16  of this document which can be consulted for more details. In the notches, the leads of the first segments  25  are in contact through their relatively wide flat surfaces with the generally radial edges of the notches. In a variant, the notches  141  are angled so that, in all cases, the flat surface of each input extends along the first segment into a generally radial plane. In variants, no notches are provided as described, for example, in document U.S. Pat. No. 5,097,167 which can be consulted for more details. Thus, insulating plates and resin elements are provided at the ends of the chignons. The first segments  25  cross the body of the stator in all cases.

Technology Category: 5