Abstract:
The invention relates to a stator ( 10 ) and to a method for producing a stator ( 10 ) for an electric machine ( 12 ), comprising a stator body ( 34 ) which has radial stator teeth ( 14 ) for receiving sub-coils ( 17 ) of an electric winding ( 16 ). An insulating plate ( 40 ) with guide elements ( 44 ) for connection wires ( 30, 31 ) is arranged between the sub-coils ( 17 ) on an end face ( 39 ) of the stator body ( 34 ), and a separately produced wiring plate ( 52 ) is arranged axially over the insulating plate ( 40 ), said wiring plate having conductor elements ( 63 ) for electrically contacting the connection wires ( 30, 31 ) with customer-specific connection plugs (56) of a controller. The wiring plate (52) is supported directly on the end face ( 39 ) of the stator body ( 34 ) by means of spacers ( 84 ).

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The invention relates to the stator for an electric machine, and to an electric machine, and to a method for producing a stator. 
         [0002]    DE 10 2012 224 153 A1 has disclosed a stator of an electric machine, in the case of which an insulating lamination and an interconnect plate are arranged axially on a lamination stack. The stator is for example enwound with needle windings, wherein the individual sub-coils are connected to one another by means of connecting wires at the outer circumference of the interconnect plate. Here, the entire winding is wound continuously in unipartite fashion by means of a single winding wire. 
         [0003]    For the electrical contacting of the winding with a control unit, it is necessary in said embodiment to provide a further, customer-specific terminal plate which has plug connections (not illustrated) to the control unit. A customer terminal plate of said type is mounted axially onto the interconnect plate, such that the axial manufacturing tolerances of the insulating lamination, of the interconnect plate and of the customer terminal plate are added together. As a result, the plug connections to the control unit do not have a clearly defined axial position, which can give rise to contacting problems with regard to the control unit. 
       SUMMARY OF THE INVENTION 
       [0004]    The apparatus according to the invention and the method according to the invention have the advantage in relation to this that, as a result of the integral formation of axial spacers on the interconnect plate, the latter can be supported directly on the face surface of the stator body, without the interposition of further structural elements. As a result, the manufacturing tolerances of the insulating lamination and of a possible further interconnect disk are eliminated, whereby the tolerances for the terminal plugs are dependent only on the manufacture and installation of the interconnect plate with the conductor elements fastened thereto. With this short tolerance chain, very exact positioning of the terminal plugs with respect to a reference surface of the motor housing can be realized. 
         [0005]    The interconnect plate is particularly expediently in the form of a closed plastics ring, the internal cutout of which can receive the rotor. On the plastics body, the holding elements for the terminal plugs are formed on one side in the axial direction, and the spacers, which bear against the face side of the stator body, are formed axially on the opposite side. Since the conductor elements with the terminal plugs are fixedly connected to the interconnect plate, it is possible by means of the integral form of the entire plastics body of the interconnect plate for the manufacturing tolerances with regard to the axial position of the plug connection to the control unit to be considerably reduced. 
         [0006]    In order that a collision between the connecting wires of the individual sub-coils does not occur, the ring-shaped region of the interconnect plate is inserted radially within the guide elements of the insulating lamination. The guide elements thus constitute a radial separation between firstly the conductor elements, arranged within the guide elements, on the plastics ring and secondly the connecting wires arranged radially at the outside on the guide elements. In this way, an electrical short circuit in the interconnect is avoided. The spacers are likewise integrally formed radially outside the guide elements and extend axially past the connecting wires to the face surface of the stator. 
         [0007]    It is particularly advantageous for the spacers to be integrally formed axially exactly opposite the holding elements, because then, the force acting on the holding elements during the contacting of the control unit is optimally absorbed. Since the spacers are situated radially at the outermost circumference, they can advantageously be formed integrally with the holding elements via connecting struts, in particular by means of injection molding. 
         [0008]    In order that the spacers can bear axially directly against the face side of the stator body, passage openings are correspondingly cut out axially in the insulating lamination, which passage openings allow free access to the uppermost sheet-metal lamination of the stator body. To prevent a collision of the spacers with the guide elements and connecting wires, the passage openings in the insulating lamination are likewise arranged at the radially outermost edge. In terms of manufacturing, the passage openings are formed in a very simple manner as radially open holes by means of injection molding, wherein, after the installation of the stator into the motor housing, the latter radially closes off the passage openings. 
         [0009]    It is particularly advantageous if the spacers form a clip or detent connection with the passage openings, because then, the interconnect plate is reliably fixed in the axial direction—and in particular also with respect to the circumferential direction—until the conductor elements are connected to the connecting wires. 
         [0010]    It is preferable for elastically movable detent elements to be integrally formed on the spacer, which detent elements are formed for example as resilient webs, the longitudinal axis of which extends approximately in the axial direction. On the resilient web there is then formed, for example, a detent hook which engages into a corresponding counterpart element on the passage opening. 
         [0011]    For this purpose, it is for example the case that a cutout is formed in a circumferential direction on the wall of the passage opening axially toward the face side of the stator body, which cutout forms an axial undercut for the detent element. 
         [0012]    Thus, during the axial insertion into the passage opening, the resilient web is deflected with respect to the circumferential direction, wherein, after the spacer has been fully inserted into the passage opening, the detent hook engages with detent action into the undercut in order to fix the interconnect plate axially to the stator body. 
         [0013]    To also achieve reliable exact positioning with respect to the circumferential direction without additional outlay, the resilient webs on at least two spacers are arranged in opposite circumferential directions. In this way, said two spacers are braced against one another with respect to the circumferential direction, whereby tolerances can be compensated, which is necessary for the installation of the interconnect plate. 
         [0014]    For exact axial positioning of the terminal plugs, the holding elements preferably have, in the region of their free axial ends, an axial abutment surface on which the terminal plugs are axially supported. For this purpose, the method for fastening the conductor elements on the interconnect plate, for example by means of plastics rivets, is decoupled from the axial positioning of the terminal plugs. In this way, any inaccuracies in the welding of the fastening sections to the connecting wires or in the connection of the central sections to the plastics body do not lead to any positional deviation of the terminal plugs with respect to the face side or the reference surface of the motor housing. 
         [0015]    It is particularly expediently possible for the stator body to be constructed by means of the punched sheet-metal laminations, which have a sheet-metal section which is closed in the circumferential direction. Such a “full section” stator can be easily enwound, for example by means of needle winding methods, wherein a so-called tooth slant can optionally be generated by virtue of the sheet-metal laminations being rotationally offset relative to one another by a small angle in the circumferential direction. In this way, despite identically manufactured sheet-metal laminations, the detent torque of an electric motor can be considerably reduced. 
         [0016]    Through the reduction of the axial tolerances in the installation of the interconnect plate, an electric machine according to the invention can be manufactured in which both the face side of the stator stack and the axial ends of the terminal plugs have an exactly predefined dimension relative to a reference surface on the motor housing. In this way, it is also possible for the bearing cover for the rotor of the electric machine to be exactly axially positioned, such that the leadthroughs thereof can receive the holding elements with the terminal plugs as plug base, whereby a clearly defined interface for the control unit is provided. 
         [0017]    The production method of the stator with the method steps according to the invention has the advantage that, firstly, the interconnect plate bears directly against the face side of the stator body with small tolerance, and at the same time, through the design of the detent connection, the interconnect plate is reliably fixed to the stator body both axially and in the circumferential direction. This prevents, during the installation process, a displacement of the interconnect plate until the conductor elements of the interconnect plate have been firmly contacted with the connecting wires. Through the reduction of the axial tolerance chain, a clearly defined interface between the bearing cover with the terminal plugs to the connecting plugs of the control unit can be created. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]    Exemplary embodiments of the invention are illustrated in the drawings and discussed in more detail in the following description. In the drawings: 
           [0019]      FIG. 1  schematically shows a winding diagram according to the invention, 
           [0020]      FIG. 2  shows an insulating lamination according to the invention, 
           [0021]      FIG. 3  shows a first exemplary embodiment of a wound stator with insulating lamination, 
           [0022]      FIG. 4  shows a corresponding plan view as per  FIG. 3 , 
           [0023]      FIGS. 5 and 6  show an exemplary embodiment as per  FIG. 3  with a first embodiment of a mounted interconnect plate, 
           [0024]      FIGS. 7 and 8  show an exemplary embodiment as per  FIG. 3  with a second embodiment of a mounted interconnect plate, 
           [0025]      FIG. 9  shows the interconnect plate as per  FIGS. 7 and 8  without a stator, and 
           [0026]      FIG. 10  shows a stator inserted into a motor housing. 
       
    
    
     DETAILED DESCRIPTION 
       [0027]      FIG. 1  schematically illustrates a cut-open stator  10 , on the stator teeth  14  of which the winding diagram of an electrical winding  16  is illustrated. The stator  10  has for example twelve stator teeth  14 , wherein in each case always exactly one sub-coil  18  is wound onto each stator tooth  14 . Here, in each case two sub-coils  18  situated immediately adjacent to one another are connected by means of a short connecting wire  31  to form an adjacent sub-coil pair  17 . The winding is commenced for example with a first wire start  28  on the second stator tooth  14 , and a connecting wire  30  is led to the fifth stator tooth  14 . Immediately after the fifth stator tooth  14 , the sixth stator tooth  14  is wound, such that said sub-coil pair  17  is connected by means of the short connecting wire  31  of two immediately adjacent sub-coils  18 . After the sixth stator tooth  14 , the winding wire  22  is led by means of the connecting wire  30  to the third stator tooth  14 , in order there to form a sub-coil pair  17 , which is connected by means of the connecting wire  31 , to the fourth stator tooth  14 . From the fourth stator tooth  14 , the winding wire  22  is led via the connecting wire  30  in the first stator tooth  14 , where the wire end  29  of the first winding strand  24  is arranged immediately adjacent to the wire start  28 . The second winding strand  25  is wound, with a separate winding wire  22 , correspondingly to the winding of the first winding strand  24 , such that a further three sub-coil pairs  17  of immediately adjacently arranged sub-coils  18  are formed, which are connected by means of a short connecting wire  31 . The wire start  28  and the wire end  29  of the two winding strands  24 ,  25  are in each case electrically connected to one another. In this embodiment, after the winding, it is always the case that two sub-coil pairs  17  are connected to form a phase  26 , such that a total of exactly three phases U, V, W with in each case four sub-coils are formed. The first three sub-coil pairs  17  form an independent winding strand  24  which is wound from a separate winding wire  22  and which is insulated with respect to the second winding strand  25 , which likewise has three sub-coil pairs  17  (as is illustrated by means of the dash-dotted line between the sixth and the seventh stator tooth  14 ). With such a winding, it would thus be possible for six separate phases to be actuated. In our embodiment, however, two radially exactly oppositely situated sub-coil pairs  17  composed of different winding strands  24 ,  25  are electrically connected to one another by means of conductor elements  58  of an interconnect plate  52  in order to reduce the electronic complexity of the control unit. 
         [0028]      FIG. 3  now shows a three-dimensional view of a stator  14  which has been wound correspondingly to the winding diagram from  FIG. 1 . The stator  14  has a stator body  34  which is for example assembled from individual sheet-metal laminations  36 . Here, the stator body  34  comprises a ring-shaped closed return yoke  38  on which the stator teeth  14  are radially inwardly integrally formed. In the interior, the stator  14  has a circular cutout  37  into which a rotor (not illustrated) can be inserted, as can be seen more clearly in  FIG. 4 . The stator teeth  14  extend inward in a radial direction  4  and along the rotor axis in an axial direction  3 . In the exemplary embodiment, the stator teeth  14  are formed so as to be skewed in the circumferential direction  2  in order to reduce the detent torque of the rotor. For this purpose, it is for example the case that the sheet-metal laminations  36  are correspondingly rotationally offset with respect to one another in the circumferential direction  2 . Before the stator body  34  is enwound, insulating laminations  40  are mounted onto the two axial face sides  39  in order to electrically insulate the winding wire  22  with respect to the stator body  34 . At least one of the two insulating laminations  40  has a ring-shaped closed circumference  41 , from which insulating teeth  42  extend in the radial direction  4 , which insulating teeth cover the face sides  39  of the stator teeth  14 . On the ring-shaped circumference  41  of the insulating lamination  40 , there are formed guide elements  44  in which the connecting wires  30 ,  31  are led between the sub-coils  18 . For this purpose, it is for example the case that grooves  45  in the circumferential direction  2  are formed on the outer circumference  41 , such that the connecting wires  30 ,  31  are arranged in axially offset planes in order to prevent the connecting wires  30 ,  31  from crossing over. The short connecting wires  31  between the sub-coil pairs  17  are arranged in the uppermost axial plane, wherein in particular, all six connecting wires  31  for the contacting of the phase terminals all run in the same axial plane. For this purpose, two axial projections  46  are always formed between two sub-coils  18  of a sub-coil pair  17 , which projections are separated from one another by an interposed radial aperture  47 . Thus, the short connecting wires  31  of the sub-coil pairs  17  are freely accessible from all sides and, in particular in the region of the radial aperture  47 , do not bear against the insulating lamination  40 . The two wire starts  28  and wire ends  29  are, in this exemplary embodiment, fixed in a labyrinth arrangement  50 , which is arranged in each case immediately adjacent, in the circumferential direction  2 , to the two axial projections  46  which are spaced apart by a radial aperture  47 . It can thus be seen in  FIG. 3  that the wire start  28  of the first winding strand  24  runs, over the circumferential region of the radial aperture  47 , parallel and immediately adjacent to the wire end  29  of the first winding strand  24 . Here, the wire start  28  is arranged in a first labyrinth arrangement  50  on one side of the radial aperture  47 , and the wire end  29  of the first winding strand  24  is arranged in a second labyrinth arrangement  50  opposite the radial aperture  47  in the circumferential direction. By means of this parallel arrangement of the short connecting wires  31 , these can be electrically contacted in the same way as the connecting wires  31  of the continuously wound sub-coil pairs  17  for the purposes of the phase actuation. 
         [0029]    In  FIG. 4 , it can likewise be clearly seen that the two connecting wires  31  running parallel are arranged at the same radius. The free ends of the wire start  28  and of the wire end  29  end directly after the corresponding labyrinth arrangements  50 , such that they do not protrude radially beyond the connecting wires  30 ,  31 . The connecting wires  30 ,  31  all run in the circumferential direction  2  along the guide elements  44  and lie radially outside the sub-coils  18  wound onto the stator teeth  14 . In  FIG. 4 , the two motor halves  11  are likewise schematically separated by the dash-dotted line, wherein the left-hand motor half  11  is electrically insulated with respect to the right-hand motor half  13 . The electrical winding  16  is manufactured for example by means of needle winding, wherein the connecting wires  30 ,  31  can, by means of a winding head, be led radially outward between the sub-coils  18  and laid in the guide elements  44 . In this embodiment, all connecting wires  30 ,  31  are arranged axially on one side of the stator body  34 . In an alternative embodiment which is not illustrated, it is also possible for a part of the connecting wires  30 ,  31  to be laid onto the axially opposite side of the stator  14 . Here, it is for example possible for the short connecting wires  31  for the contacting of the phase actuation to be arranged in a first insulating lamination  40 , and for the other connecting wires  30 , which connect the different sub-coil pairs  17  to one another in each case, to be led on the axially oppositely arranged insulating lamination  40 . 
         [0030]    In  FIG. 5 , a first embodiment of an interconnect plate  52  has been mounted onto the embodiment of the stator  10  as per  FIG. 3 , by means of which interconnect plate the electrical winding  16  is actuated. For this purpose, the interconnect plate  52  has terminal plugs  54  to which the customer-specific connecting plugs  56  of a control unit can be joined. In this embodiment, exactly six terminal plugs  54  are provided, which are in each case electrically connected to one sub-coil pair  17  of the electrical winding  16 . Here, exactly  6  phases  26  are formed by in each case exactly one sub-coil pair  17 , such that the six terminal plugs  54  are contacted with exactly six connecting wires  31  of adjacent sub-coil pairs  17 . For this purpose, the interconnect plate  52  has exactly six conductor elements  58  which, on an axially angled end, have the terminal plugs  54 , and on the other end, have a fastening section  60  which is connected, for example welded, to the connecting wires  31 . The interconnect plate  52  has a plastics body  62  which is formed as a closed ring through which the rotor can be inserted into the stator  10 . On the plastics body  62  there are integrally formed holding elements  63  which extend away from the stator body  34  in the axial direction  3 . The conductor elements  58  extend in the circumferential direction  2  along the plastics body  62 , wherein the angled terminal plugs  54  are led in the axial direction  3  within the holding elements  63 . On the other end, the conductor elements  58  have the fastening section  60 , the free end of which is formed as a loop  64  which surrounds the connecting wire  31 . Here, the loop  64  is formed from a sheet-metal material, the cross section of which is approximately rectangular. In the exemplary embodiment, the conductor elements  58  are formed as bent and punched parts  59  composed of sheet metal, such that the loop  64  can be bent out of the free end of the fastening section  60 , during the installation thereof, around the connecting wire  31 . After the arrangement of the open loop  64  around the connecting wire  31 , it is for example the case that electrodes are laid onto both radially oppositely situated surfaces of the loop  64 , which electrodes are pressed together in the radial direction  4  while being fed with current in order to weld the loop  64  to the connecting wire  31 . Here, the insulating lacquer of the connecting wire  31  is melted, resulting in metallic cohesion between the fastening section  60  and the connecting wire  31 . The loop  64  is laid around the connecting wire  31  in the region of the radial aperture  47 , because in this region, no guide element  44  is arranged between the connecting wire  31  and the loop  64 . As a result, sufficient free space is available for the electrodes to be laid on, such that a free limb end  65  of the loop  64  can be pressed against the fastening section  60 , whereby the loop  64  is closed. Here, depending on the sub-coil pair  17 , the loop  64  surrounds only a single connecting wire  31  or simultaneously surrounds  2  connecting wires  31  which run parallel to one another and which are formed from the wire start  28  and the wire end  29  of a single winding strand  24 ,  25 . The terminal plugs  54  are for example formed as insulation-displacement connections  55  which, at their free axial end  68 , have a notch  69  into which a wire or a clamping element of the corresponding connecting plug  56  of the customer can be inserted. For this purpose, it is for example the case that detent engagement means  124  are integrally formed on the end  68 , which detent engagement means dig firmly into the corresponding connecting plug  56 . Furthermore, a transverse web  70  is formed in the radial direction  4  on the terminal plug  54 , which transverse web is correspondingly supported on an axial stop  72  of the holding element  63 . Furthermore, on the holding element  63 , a first guide surface  74  and a second guide surface  75  are formed which support the terminal plug  54  in the two opposite circumferential directions  2 . This prevents the terminal plugs  54  from bending over or bending out in the circumferential direction  2  during the insertion of the connecting plugs  56 , whereby the axial tolerances of the plug connection are ensured. 
         [0031]    The conductor elements  58  are arranged at least partially radially adjacent to one another, whereby it is necessary for the fastening sections  60  of the inner conductor elements  58  to radially cross the outer conductor elements  58  in order to be contacted with the connecting wires  31 . Therefore, the radially inner conductor elements  58  are arranged on an axially higher path  76 , and the radially outer conductor elements  58  are arranged on an axially lower-lying path  77  of the plastics body  62 . Here, the central sections  78 , which are in the form of sheet-metal strips, of the conductor elements  58  bear areally against the plastics body  62  and are connected to the latter for example by means of rivet connections or detent components. For this purpose, it is for example the case that axial rivet pins  79  are formed on the plastics body  62 , which rivet pins engage through into corresponding axial apertures  80  of the conductor elements  58 . By means of heat, in particular ultrasound, the ends of the rivet pins  79  can be deformed to form a rivet head  81 , which forms a form fit with the conductor elements  58 . 
         [0032]    In the exemplary embodiment of  FIGS. 5 and 6 , it is always the case that two terminal plugs  54  are arranged in a common holding element  63 , wherein said terminal plugs are separated from one another in the circumferential direction  2  by a central web  82  of the holding element  63 . Here, the central web  82  forms, on both sides, in each case a first and a second guide surface  74 ,  75  for the respectively abutting terminal plugs  54 . The second and first guide surfaces  75 ,  74  situated in each case opposite the central web  82  are formed by corresponding counterpart surfaces  83  which extend in the radial direction  4  and axial direction  3 . In the region of the holding elements  63 —axially opposite these—there are integrally formed spacers  84  which support the interconnect plate  52  axially with respect to the stator body  34 . In the exemplary embodiment of  FIGS. 5 and 6 , exactly one holding element  63  has a greater width  85  in the circumferential direction  2  than the two other holding elements  63 . In this way, a rotation prevention means is realized for a bearing cover (not illustrated) which is mounted axially with correspondingly shaped axial openings onto the holding elements  63 . 
         [0033]      FIG. 6  shows how the two terminal plugs  54  bear at both sides against the central web  82 . Angled in each case in opposite circumferential directions  2 , the respective central section  78  of the conductor element  58  is situated adjacent. Since the conductor elements  58  situated radially adjacent to one another are arranged on axially different paths  76 ,  77 , said conductor elements do not make contact, such that they are electrically insulated with respect to one another. The inner ring of the plastics body  62  is of slightly undulating form in order that a punch tool for the insertion of the stator  10  into a motor housing can be engaged directly on the face side  39  of the radially inner regions of the stator teeth  14 . 
         [0034]    In  FIG. 7 , as a further exemplary embodiment, an alternative interconnect plate  52  by means of which the electrical winding  16  is actuated has been mounted onto the embodiment of the stator  10  as per  FIG. 3 . This embodiment corresponds to the actuation with exactly three phases U, V, W according to the schematic illustration in  FIG. 1 . In this embodiment, the interconnect plate  52  has exactly three terminal plugs  54  onto which customer-specific connecting plugs  56  of a control unit can be joined. Each terminal plug  54  is a constituent part of a conductor element  58  which electrically connects a first sub-coil pair  17  to a second—in particular radially exactly oppositely situated—sub-coil pair  17 . For this purpose, proceeding from the terminal plug  54  extending in the axial direction  3 , a first branch  90  and a second branch  91  are arranged so as to be angled in the circumferential direction  2 . The two branches  90 ,  91  together form approximately a semicircle and extend along the ring-shaped plastics body  62 , wherein said branches, at their ends averted from the terminal plug  54 , have fastening sections  60  for the electrical contacting with the connecting wires  30 ,  31  of the sub-coils  18 . The first branch  90  of a first conductor element  58  is arranged radially within the second branch  91  of a second conductor element  58 . The fastening section  60  of the first, inner branch  90  therefore crosses the second, outer branch  91  of the second conductor element  58  in the radial direction  4  without making contact therewith. Here, the radially inner branches  90  are arranged on an axially higher path  76  than the radially outer branches  91 , which are arranged on an axially lower-lying path  77  of the plastics body  62 . The conductor elements  58 , which are in the form of sheet-metal strips, bear areally against the plastics body  62  and are connected to the latter for example by means of rivet connections or detent components. For this purpose, it is for example the case that axial rivet pins  79  are formed on the plastics body  62 , which rivet pins engage into corresponding axial apertures  80  of the conductor elements  58 . By means of heat, in particular ultrasound, the ends of the rivet pins  79  can be deformed to form a rivet head  81 , which forms a form fit with the conductor elements  58 . Thus, it is for example the case that each branch  90 ,  91  is fastened by means of in each case two rivet heads  81  to the interconnect plate  52 , as can be seen particularly clearly in  FIG. 8 . On the plastics body  62 , there are again integrally formed holding elements  63  which extend away from the stator body  34  in the axial direction  3  and receive the terminal plugs  54 . The terminal plugs  54  are for example likewise formed, as in  FIG. 5 , as insulation-displacement connections  55  which, at their free axial end  68 , have a notch  69  into which a wire or a clamping element of the corresponding connecting plug  56  of the customer can be inserted. In this embodiment, the holding elements  63  are of two-part form. A radially inner axial projection  92  forms a first guide surface  74  in a first circumferential direction  2 , and a radially outer axial projection  93  forms the second guide surface  75  for the opposite circumferential direction  2 . The two axial projections  92 ,  93  are arranged offset in the circumferential direction  2 , such that the terminal plug  54  extends in the axial direction  3  between the guide surfaces  74 ,  75  of said axial projections. The axial projections  92 ,  93  have in each case one support surface  95  with respect to the radial direction  4 , against which the terminal plug  54  is radially supported. For this purpose, the axial projections  92 ,  93  have for example an L-shaped or U-shaped cross section transversely with respect to the axial direction  3 . With respect to the axial direction  3 , the radially extending transverse web  70  is supported on axial stops  72  of the holding element  63 . The axial projections  92 ,  93  are offset in the radial direction  4  to such an extent that they do not overlap in the radial direction  4 . In this way, openings  98  are formed in the holding element  63  in each case in both circumferential directions  2 , from which openings the two branches  90 ,  91  emerge from the holding element  63  in opposite circumferential directions  2 . In order that the conductor elements  58  can be installed axially into the holding elements  63 , the openings  98  are upwardly open in the axial direction  3 . The angled portions  100  of the branches  90 ,  91  toward the terminal plug  54  are arranged radially adjacent to one another and in axially different planes, in order that the branches  90 ,  91  can extend on the axially different paths  76 ,  77  of the plastics body  62 . 
         [0035]    It can be seen from  FIG. 8  that the branches  90 ,  91  are arranged radially in the region of the stator teeth  14  and radially within the guide elements  44  of the insulating lamination  40 . The three holding elements  63  are arranged so as to be uniformly distributed in the circumferential direction  2  at intervals of approximately 120°. Again, one holding element  63  has, as a rotation prevention means, a relatively large width  85  in the circumferential direction  2 . For this purpose, the two axial projections  92 ,  93  are of U-shaped form, such that their free limbs  87  point toward one another in the circumferential direction  2 . The face surfaces  88  of the free limbs  87  in this case form guide surfaces  106  in the circumferential direction  2  (which correspond to the first and second guide surfaces  74 ,  75 ) between which the terminal plugs  52  are arranged. 
         [0036]      FIG. 2  illustrates an embodiment according to the invention of an insulating lamination  40  without a stator body  34 . The radial insulating teeth  42  have grooves  43  for the compact enwinding of the individual sub-coils  17 . The guide elements  44 , which are arranged so as to be distributed over the entire circumference and which extend axially, form the radial separation between the sub-coils  17  (not shown here) and the connecting wires  30 ,  31 . On the ring-shaped circumference  41  there are formed—for example three—axial passage openings  108  into which spacers  84  (not yet illustrated) of an interconnect plate  52  can extend through in order to be supported directly on the stator body  34 . The insulating lamination  40  bears axially likewise directly against the face side  39  of the stator body  34 , which is formed directly by the axially outermost sheet-metal lamination  36 . The outer circumference  41  extends radially approximately as far as the outer circumference of the lamination stack  35 . Here, the passage openings  108  are of radially open form in order that the spacers  84  bear against the radially outermost edge of the stator body  34 . On the edge  109  of the passage opening  108  there are formed, as counterpart detent elements  111 , undercuts  115  with which the corresponding detent elements  110  of the spacers  84  form a detent connection  112 . The undercuts  115  are cut out on that axial side of the insulating lamination  40  which faces axially towards the stator body  34 , and thus form a detent surface at which the detent elements  110  of the spacers  84 , with detent hooks  113 , can firmly clamp axially against the stator body  34 . The undercuts  115  extend for example in the circumferential direction  2 , preferably at both edges  109  situated opposite in the circumferential direction  2 . Said undercuts extend, in the exemplary embodiment, as far as the radially outer edge  41  of the insulating lamination  40 . The passage openings  108  extend radially inward, and the undercuts  115  extend no further inward than the outer circumference of the connecting wires  30 ,  31 . 
         [0037]    After the insulating lamination  40  arranged on the stator body  34  has been enwound, an interconnect plate  52  as per  FIGS. 5-8  is inserted axially over the insulating lamination  40 . The interconnect plate  52  of  FIG. 7  is illustrated once again in  FIG. 9 , without a stator body  34  and on an enlarged scale. The free ends of the fastening sections  60  are, as in  FIG. 5 , again formed as loops  64 , which are still open before the installation of the conductor elements  58  and which, after the installation thereof, surround the connecting wires  31 . As can be seen in  FIG. 9 , the spacers  84  are integrally formed, in unipartite fashion with the holding elements  63 , axially opposite these on the plastics body  62 . The spacers  84  project beyond the ring-shaped plastics body  62  of the interconnect plate  52  in the axial direction  3  and are integrally formed radially outside the plastics ring  62 . Here, said spacers are connected to the interconnect plate  52  in unipartite fashion by means of support webs  66 . During the mounting onto the stator body  34 , the spacers  84  engage over the connecting wires  30 ,  31  in the radial direction  4  in order to engage, outside said connecting wires, axially into the passage openings  108  of the insulating lamination  40 . 
         [0038]    In this way, the interconnect plate  52  with the terminal plugs  54  can be supported directly on the stator body  34  without any intermediate components. In the exemplary embodiment, three holding elements  63  and therefore also three corresponding passage openings  108  are formed, which are preferably distributed uniformly over the circumference. The detent elements  110  are formed in unipartite fashion on the spacers  84 , which detent elements engage into the counterpart detent elements  111  of the insulating lamination  40  in order to reliably fix the interconnect plate  52  to the stator body  34 . The detent elements  110  are formed as spring tongues  114  which extend in the axial direction  3  approximately parallel to the spacers  84  and which are of resilient form at least with respect to the circumferential direction  2 . An axial gap  116  is thus formed, toward which the detent element  110  is pushed during the insertion into the passage opening  108 . On the free end of the detent elements  110  there are integrally formed detent hooks  113  which, when the spacers  84  have been fully inserted, engage with detent action into the undercuts  115  in the circumferential direction  2  and form an axial form fit. If the detent elements  110  are arranged such that two of them engage with detent action with the counterpart detent elements  111  in opposite circumferential directions  2 , the interconnect plate  52  is also reliably exactly positioned relative to the sheet-metal lamination stack  35  with respect to the circumferential direction  2 . For example, it is thus the case that only exactly two spacers  84  have in each case exactly one detent element, wherein in each case two counterpart detent elements  113  are formed on at least two passage openings  108 . In the exemplary embodiment, the third spacer  84  has no detent element  110 , in order that said third spacer can be manufactured with greater precision with respect to the circumferential direction  2 , in order, with respect to the circumferential direction  2 , to form an exact fit with the third passage opening  108 , on which preferably no counterpart detent elements  111  are integrally formed. 
         [0039]    In the embodiment as per  FIG. 5 , the passage openings  109  are formed such that, on the outer circumference  41  of the insulating lamination  44 , there are integrally formed radial holding webs  107  which position the spacers  84  in the circumferential direction  2 . Here, the radius of the circumference  41  is smaller than the radius of the stator body  34 , such that the cross section of the spacer  84  fits radially into said radius difference. In this embodiment, no detent elements  110  are integrally formed on the spacer  84 , and no counterpart detent elements  113  are integrally formed on the insulating lamination  40 . In the embodiment as per  FIG. 7 , the radius of the circumference  41  is approximately equal to the radius of the stator body  34 , such that the passage openings  108  are cut out of the circumference  41  of the insulating lamination  44 . Here, the spacers  84  have detent elements  110  which engage into the corresponding counterpart detent elements  113  of the passage openings  108 . 
         [0040]    In  FIG. 10 , the stator  10  has been inserted into a motor housing  120 , preferably by shrink-fitting. Here, from a manufacturing aspect, the face surface  39  of the stator body  34  is fastened with a defined spacing  118  to a reference surface  119  of the motor housing  120 . By virtue of the fact that the interconnect plate  52  with the spacers  84  bears directly against the face surface  39 , the free ends  68  of the terminal plugs  54  of the interconnect plate  52  also have a defined spacing  117  to the reference surface  119 . It is thus possible for a bearing cover  121  to be inserted axially into the motor housing  120  into a defined position relative to the reference surface  119 , such that the holding elements  63  project through corresponding apertures  122  in the bearing cover  121 . To form the rotation prevention means, at least one aperture  122  has a different contour and is for example of wider form in the circumferential direction  2  than the other two apertures  122 . By means of this manufacturing method, an exactly reproducible interface for the control unit is provided.