Title of Invention	METHOD FOR PRODUCING A MAGNETICALLY EXCITABLE CORE HAVING A CORE WINDING FOR AN ELECTRICAL MACHINE
Abstract	Abstract A method is proposed for producing a core which can be excited electromagnetically for an electrical machine, according to which, in a method step (SI) , a core (24) is produced which essentially has a cuboids shape (20) with slots (32) running parallel on one side and in whose slots (32) in a method step (S2) , the winding sides (36) of a core winding (40) are inserted and then, in a method step (S3), the core (24) together with the core winding (40) is deformed into a cylindrical annular shape (52) with the slots (32) pointing radically inwards. The method is characterized by a further step, according to which all the winding sides (36) , which are inserted into a respective slot (32), are pressed and formed in a tool (44) into a slot shape (119) before being inserted into the slot (32), Furthermore, a stator (150) produced using this method and an electrical machine (14 0) having this stator (150) are proposed. (Figure 6E)

Title of Invention

METHOD FOR PRODUCING A MAGNETICALLY EXCITABLE CORE HAVING A CORE WINDING FOR AN ELECTRICAL MACHINE

Abstract

Abstract A method is proposed for producing a core which can be excited electromagnetically for an electrical machine, according to which, in a method step (SI) , a core (24) is produced which essentially has a cuboids shape (20) with slots (32) running parallel on one side and in whose slots (32) in a method step (S2) , the winding sides (36) of a core winding (40) are inserted and then, in a method step (S3), the core (24) together with the core winding (40) is deformed into a cylindrical annular shape (52) with the slots (32) pointing radically inwards. The method is characterized by a further step, according to which all the winding sides (36) , which are inserted into a respective slot (32), are pressed and formed in a tool (44) into a slot shape (119) before being inserted into the slot (32), Furthermore, a stator (150) produced using this method and an electrical machine (14 0) having this stator (150) are proposed. (Figure 6E)

Full Text	Method for producing a core which can _ be excited magnetically and has a core winding for an electrical machine, a core which can be excited magnetically, is produced using the method and has a core winding, and an electrical machine having a core which is produced using the method and has a core winding Prior art A production method for the stator of an electrical machine according to theprecharacterizing clause of Claim 1 is already known from Japanese Laid-open Specification 5-103 052. In order to produce this stator, individual sheet-metal laminates are first of all stamped out, and a specific number of these sheet-metal laminates are formed into layers superimposed one on top of the other until the desired axial width of the core is achieved. These sheet-metal laminates formed into layers form the stator core, which thus has chew normal teeth and slots, aligned parallel to one another, on one side for a stator. An already pre-wound core winding, which is in the form of a distributed wave winding, is provided in an approximately planar form, and is then inserted into the slots in the essentially flat core. The flat assembly comprising the core and core winding has what is referred to as a winding overhang, that is to say each individual one of the total of three phases has a winding side which is initially not inserted into slots. This assembly comprising the core and core winding is then bent around so as to produce a conventional, hollow-cylindrical stator. In the process, the overhanging winding sides must finally be inserted into the corresponding slots before completion of the stator. As a result: of this production process, the core has two ends which must be placed flush against one another when the core together with the core winding is bent around. These two ends are geometrically placed into the slot base of one core slot. This prior art has the disadvantage that, despite the good access to the slots, the filling level is not optimum. Advantages of the invention The invention is based on the knowledge that the slots, which are widened before the laminated core is bent around, must be filled such that the inserted winding corresponds at least approximately to the shape of the slots after the bending-around process, even before said bending-around process is carried out, with a certain amount of compression within the inserted winding invariably being desirable. The method according to the invention for producing a core for an electrical machine therefore provides that, before they are inserted into the slots in the core, all the winding sides of the core winding are pressed and shaped into a slot shape in a tool. This is a highly advantageous measure since relatively high slot filling factors of 55% or more are thus achieved. This prevents the prefabricated assembly comprising the flat core and core winding from having to absorb the forming work while being bent around into the hollow-cylindrical shape, and the core thus being unacceptably deformed. The measures described in the dependent claims relate to advantageous developments and improvements of the method according to the main claim. A further refinement of the invention provides that a half tooth is in each case formed in the circumferential direction at both ends of the core, which are to be connected to one another in a subsequent step, that is to say the abutting edges of the laminated core are not located, in the known manner, in a slot, but within a tooth surrounding the slots. Although this measure makes it harder to connect the abutting edges, but, if a coil with a winding overhang is inserted into the core, then this winding overhang must be inserted into 9 slot shortly before the completion of the process of bending the core or the stator around. If this slot has now' already been completely finished, there is no risk of this winding side of the winding overhang being jammed in between the two ends at the abutting edges. This reliably prevents destruction of this final winding side to be inserted, in particular in the case of a manufacturing process which is being carried out quickly, in a simple manner. Furthermore, it avoids any slot insulation which is placed around the final winding side to be inserted sliding down from this winding side while said winding side is being inserted and, in consequence, at least prevents the manufacturing process from being impeded. A further advantage of a half-formed tooth in each case is that the magnetic reluctance in the magnetic return path of the stator core is not interrupted, and magnetic losses are thus reduced. Once the core winding has been manufactured, the individual coil or lap sides occupy an envelope area which is generally larger than the actual slot area once the core has been bent around. If the winding sides are in each case pressed into a slot shape in a tool, which corresponds to the final shape of the slot in the core, before being inserted into the core, the winding sides are deformed, and the envelope area of the winding sides is matched to the actual slot area once the stator or core has been bent around. This thus avoids the individual teeth of the core exerting deformation forces on the winding sides, and in consequence possibly being bent themselves, while the stator is being bent around, that is to say the core together with the core winding, since this could possibly destroy the core. If the slot shape in the tool takes account of at least a proportion of the thickness of an insulating layer by the slot shape in the tool being reduced in size by such a proportion on the circumference of the slot shape, the winding sides are then generally pushed lightly between two teeth by the insulating layer. The winding sides and/or the core winding are thus held in a slightly damped manner in their position, with possible oscillations of the winding sides being damped, thus avoiding any varnish layer of the coil wires from being scraped off and, finally, avoiding any possible short circuit,. The insulating layer remains undamaged in particular if the entire thickness of the insulating layer is taken into account by reducing the size of the slot shape of the tool by the entire thickness of the insulating layer in comparison to the slot shape of the core slots. If a core winding is wound with a winding overhang, then this results in a very largely symmetrical structure for the two end windings at both ends of the stator core. The end windings then have no approximately wedge-shaped cutout in particular in the region of the abutment point, with such a cutout representing a through-opening which could lead to an increased noise level when air flows through it. The symmetrical structure of the end windings achieved by the winding overhang also leads to the bending resistance of the assembly, which is formed from the core and the core winding, being very largely constant over the length and circumference of the stator. The complete assembly, bent into a cylindrical annular shape and comprising the core and core winding is thus particularly accurately round. If the core winding has at least one overhanging winding side, and if the distance between this at least one overhanging winding side and the closest winding side which is not overhanging is greater than the distance between two adjacent slots, then this makes it easier to insert the overhanging winding side into the first slot before completion of the process of bending the core around, thus avoiding tensile loads between the overhanging winding side and the last winding side located in the last slot. If, when the winding sides are being pressed into the slot shape, the at least one overhanging winding side is lifted out of the plane which define [sic] the winding sides which are not overhanging, then during the bending-around process and, finally, the insertion of the overhanging coils, this avoids the winding sides from colliding with the end of the core, and possibly being damaged. A core winding in the form of a two-layer lap winding has the advantage that each lap of a phase winding firstly has wires on the inner circumference and hence in the tooth head area, and secondly has wires in the area of the slot base. Since the cooling of the end windings is generally better on the inner circumference than on the outer circumference, this in the end results in uniform cooling of a lap, and hence also of an entire phase winding. In consequence, not only is one phase winding uniformly cooled, but also the entire core winding. Each individual phase winding can be designed for the same load. If the core winding is designed as a simple, single-layer lap winding, the core winding has no overhanging winding sides, there are no overhanging winding sides needing to be inserted when the assembly comprising the core and core winding is being bent around, and the bending-around process into the annular circular shape can be carried out easily and without any problems, without any overhanging winding sides. In a further refinement of the invention, the core which is provided is bent forward to a certain extent about its core back, that is to say about the side which is not in a slot, before the insertion of the core winding into the slots, so that the slot openings are widened for insertion of the winding sides. This method step makes it possible to insert windings with winding sides which are broader than the slot opening into the core with very small slot openings in the core when it is still flat. This allows compar;atively broad configurations of the tooth heads and hence a very good transfer of the magnetic field from 9 rotor to the core, which considerably improves the efficiency. This method step also makes it possible to use wires whose smallest cross-sectional dimensions are larger than the width of the slot opening when the stator core is still in the flat state, and wires which have a cross section that is not round. If the winding overhang is inserted into the at least one slot before completion of the process of bending the core into the cylindrical annular shape, and the bending process is not completed until this has been done, the slot opening is broader than when the core has been completely bent, thus making it easier to insert the winding overhang. In order to prevent the core which has been bent into the cylindrical annular shape from no longer being deformed back through the elastic element of the bending process, the invention provides for the ends of the core to be connected to one another by techniques such as welding, soldering or bonding. Drawings The invention will be explained in more detail in the following text using exemplary embodiments and with reference to the attached drawings, in which: Figure 1 shows the method sequence for producing the core according to the invention, with the core winding, Figure 2 shows a side view of a core having a cuboid shape, and a plan view of a core winding with the core winding connections and their association with slots in the core, Figure 3 shows a three-dimensional illustration of one phase of a two-layer lap winding, Figure 4 shows a schematic combined view of all three phases of the core winding, formed from a two-layer lap winding as shown in Figure 3, Figure 5 shows details of a winding overhang of the winding shown in Figure 4, Figure 6A shows a cross section of a winding side immediately after being wound, Figure 6B shows a winding side as in Figure 6A in a pressing tool after a pressing process, Figure 6C and Figure 6D show details of the contour of a lap side after pressing. Figure 7 shows the winding overhang and its position with respect to the closest winding sides which are not overhanging, Figure 8 shows a cross section of a slot with a winding side inserted, before the bending-around process, Figure 9 shows a detail of a side view of the core when it has been virtually completely bent around, with an auxiliary apparatus for pushing the overhanging coils into the-slots 1 to 3, Figure 10 shows a version of the apparatus shown in Figure 9 for pushing the overhanging coils into the slots 1 to 3, Figure 11 shows a cross-sectional view of a slot after the bending-around process, Figure 12 shows a further exemplary embodiment relating to insulation of one winding side, Figure 13 shows a detail of a winding side, insulated as shown in Figure 12, in a slot, Figure 14 shows a three-dimensional view of a single phase of a simple, single-layer lap winding, Figure 15 shows a core winding in a cuboid core, formed from a three-phase, single-layer, simple lap winding, Figure 16 shows a simple exemplary embodiment of a distributed wave winding. Figures 17A, 17B and 17C show a further exemplary embodiment of a manufacturing method. Figure ISA shows a detail of a core with a bent-up slot and an inserted winding side, Figure 18B shows a detail of the slot shown in Figure 17A, once the core has been bent around, Figure 19A shows a core with a core winding after the end of its manufacturing process, Figure 19B shows a detail of the core with a core winding in the area of the joint, Figure 20 shows an electrical machine having a core according to the invention, with a core winding. Description of the exemplary embodiments Figure 1 shows a schematic sequence of the method according to the invention, with the major steps. A core 24 which essentially has a cuboid shape 20 and can be excited magnetically is provided in a method step SI, see also Figure 2. The core 24 has parallel-running slots 32 on one side 28. A core winding 40 has slot wire sections 105, which are arranged later in the slots 32. The slot wire sections 105 which are to be arranged in the slots 32 and are combined to form a group are referred to as winding sides 36. The core winding 40, which has winding sides 36; is pressed in a pressing tool 44 {Figure 6B) such that the winding sides 3 6 are shaped and are thus matched to the contour of a slot 32, method step S2. In a further and subsequent method step S3, the winding sides 36 of the pressed core winding 40 are inserted into the slots 32 in the core 24, see also Figure 8, The core 24 together with the core winding 40 is shaped into a cylindrical annular sliape 52), with slots 32 pointing radially inwards, in method,step S4 . Figure 2 shows a side view of the cuboid core 24. The core 24 has a cuboid shape 20 with end surfaces 56 which face away from one another. The end surfaces 56 are connected to one another by means of. a rear surface 60 and a slot surface 64. The two end surfaces 56, the rear surface 60 and the slot surface 64 define a rectangular core cross section; the core 24 has two ends 61, which each have an end surface 68. The core 24 has a total of thirty six slots 32, which are all aligned parallel to one another and are arranged in a common plane. The slots 32 all open in the same direction and end in slot openings 72, which are all located in the slot surface 64. The slots 32 are bounded by teeth 76 with parallel flanks. The teeth 76 have a tooth head 78, which ends in the slot surface 64; and have a tooth foot 80, The tooth feet 80 of the teeth 7 6 all lie in a plane which is arranged parallel to the rear s urface 60. The teeth 75 have a cross-sectional or profiled shape 82, so that the teeth 76 extend parallel to the end surfaces 68. Each tooth head 78 has two tooth strips 84, see also Figure 8, which extend in the circumferential direction when the core 24 has been bent into the cylindrical annular shape 52. Each tooth 76 is formed symmetrically with respect to a tooth centre plane 86, which is oriented parallel to the end surfaces 68. A tooth 38, which is bisected in the tooth centre plane 86, is formed on each of the two end surfaces 68 on the core 24. Thirty-five completely formed teeth 7 6 are arranged between the two half teeth 88, so that a total of thirty-six slots 32 and, when the core 24 is in the bent-around state, thirty-six teeth 76 are produced, with one of the teeth being formed from two bisected teeth 88. The entire teeth 76 and the half teeth 88 are connected integrally to one another by means of their tooth foot 80 together with a core rear 89. The core rear forms a magnetic return path for all the entire and half teeth 76 and 88. The core winding 40 is shown above the core 24, and is illustrated folded through 90 into the plane of the drawing with respect to the core 24. The core winding 40 illustrated in Figure 2 is a three-phase, two-layer lap winding 90. The three-phase lap winding 90, which is wound from coated or varnished wire 91, comprises the first phase 93 with Che connecting wires U and X, the second phase 96 with the core winding connections V and Y, and the third phase 99 with the connecting wires W and Z. The lap winding 90 is inserted with its core winding connection U into a slot 32 whose slot number is 1, the core winding connecting wire Z is inserted into a slot 32 whose slot number is 2, and the core winding connecting wire v is inserted into a slot 32 whose slot number is 3. when the core winding connections U, Z and V together with X, W and Y as well as all the winding sides 3 6 located in between are inserted into the slots whose slot numbers are 1 to 36, this core winding 40 has what is referred to as an overall winding overhang 102, which is initially not inserted into slots 32 when the core winding 40 is inserted into the core 24. Figure 3 illustrates the first phase 93 from Figiare 2 in a version which is in principle the same. The first phase 93 comprises, in the same way as the other two phases as well, slot wire sections 105 and connecting wires 107 connecting these respective slot wire sections 105, The numbers 1 to 34, shown underneath the illustration of the first phase 93, indicate which of the slot wire sections 105 are located in or are inserted into which, of the slots whose slot numbers are 1 to 34 or 1. Figure 4 shows a cross-sectional illustration of all three phases 93, 96 and 99, as shown in Figure 2, but with the first phase 93 being shown'" "only by way of example. The ' two other phases 96 and 99 are manufactured analogously to this. The numbers 1 to 36 and 3 indicate the slot numbers. Starting from the slot'; 32 whose slot number is 1, a slot wire section 105 is arranged, in a first step, from the phase end U in a position Ul corresponding to the slot 32 whose slot number is 1. The slot wire section 105, Ul is connected to the connecting wire. 107, which is not illustrated but extends to the position of the slot ,32 whose slot number is 4. The winding process is continued with the slot wire section 105, U2. The slot wire section i05, U2 is connected to a further connecting wire 107, whic'n is once again wound with a slot wire section 105, U3 to the position of the slot 32 whose slot number is 1. The winding scheme continues with a further connecting wire 107 to a position in the slot 32 whose slot number is 4 via a slot wire section 105,U4_ from where, alternately, and as illustrated in Figure 4, continues via connecting wires 107 and slot wire sections,- 105, U5 at the position of the slot 32 whose slot number is 7, and so on step-by-step, as illustrated until finally, it reaches the slot 32 whose slot number is 42, from which the slot wire section 105. U48 is passed out once again, and finally represents the phase end X of the first phase 93. It can clearly be seen that two slot wire sections 105, U45 and U47 are arranged beyond the slot 32 whose slot number is 36, and are later once again inserted into the slot 32 whose slot number is 1, and are thus placed above the slot wire sections 105- U3 and Ul. It can clearly be seen in the illustration' in Figure 4 that the individual slot wire sections 105 are located both in a first layer 110 and in a second layer 112. This applies to all three phases 93, 96 and 99. The first layer 110 will later be located in the interior of the slots 32 and the second layer 112 will later be located in the region of the slot openings 72. Although the illustration of the first phase 93 in Figure 3 differs from the illustrations in Figure 4 and Figure 2, which is due to the position of the individual slot wire sections 105 in the individual layers, this is, however, irrelevant to the manufacturing method and, finally, is also irrelevant in terms of the electrical effect. Figure 5 shows, in the form of a detail and enlarged, the area of the winding sides 3 6 which are inserted into the slots 32 whose slot numbers are 34, 35, 36, and the individual winding overhangs 115 of the three phases 93, 96 and 99. A distance dl between a winding side 36 of the second phase 96 and the winding side 36 of the third phase 99 corresponds to the distance between two slots 32 when the core 24 is in the cuboid state, see also Figure 2. The distance between the winding side 36 of the third phase 99 and the individual and first winding overhang 115 of the first phase 93 is annotated d2. This distance indicates the distance between the final winding side 3 6 to be inserted into the core 2 4 before the bending-around process, and the first winding overhang 115 which can no longer be inserted into the flat core 24. The distance d2 is greater than the distance dl. The distance between the individual winding overhangs 115 of the three phases 93, 96 and 99 corresponds to the distance dl. Figure 6A shov;s the cross section of an individual winding side 36. The cross section of an individual winding side 36 initially consists of the cross sections of individual slot wire sections 105, which are initially arranged to a greater or lesser extent in an unorganized manner within a specific envelope area 118. In this case, more laps or turns have been wound than in the illustration in Figures 3, 4 and 5. As has already been mentioned with regard to Figure 1, the winding sides 36 are shaped in a pressing tool, before being inserted into the slots 32 in the core 24, such that the envelope area 118 finally matches the slot shape 119 of the pressing tool 44, see also Figure 6B. To do this, the winding side 36 is first of all inserted loosely into the slot shape 119 of the pressing tool 44, as shown by the direction of the arrow in Figure 6B. A die 120 then presses the winding side 36 into the slot shape 119, and in the process plastically deforms the winding side 36 in such a manner that its outermost envelope area IIS permanently assumes the slot shape 119. The slot shape 119 of the pressing tool 44 can thus be designed such that it corresponds to the cross-sectional shape of the slots 32 after the bending process. One version provides for the slot shape 119 to correspond to the slot cross-sectional shape of the slots 32 minus at least a proportion of the material thickness diso of an insulating layer 123, see also Figures 6C and 6D, as well as Figure 8. If, as illustrated in Figure 4, the core winding 40 is wound with an overall winding overhang 102, then the overall winding overhang 102 is at the same level as the second layer 112. The pressing of the core winding 40 in the pressing tool 44 provides for the overall winding overhang 102 at the same time to be lifted out of the plane formed by the second layer 112. The individual winding overhangs 115 have lower faces, which will later face the first layer 110. These lower faces of the individual winding overhangs 115 are raised beyond the second layer 112 by the pressing process in the pressing tool 44 and lie on a curve K, which is within what will later be the diameter of the core 24, which will later be round. After the pressing and shaping of the winding sides 36 of the core winding 40, the core winding 40 is inserted together with the winding sides 36 into the slots 32, which are lined with the insulating material 123, Figure 8. The prefabricated assembly, formed from the core 24, the insulating material 123 and the core winding 44, is shaped in the next method step S4 into a cylindrical annular shape 52 with slots 32 pointing radially inwards. This process starts with the 'half tooth 88, which is adjacent to the slot 32 whose slot nuinber is 36. The half tooth 88 is bent in a tool with respect to the closest tooth 76 between the slots 32 whose slot numbers are 35 and 36, so that the tooth heads 7 8 become closer to one another and the slot openings 72 are reduced in size. In the process and at the same time, a rear section 140 between the half tooth 88 and the tooth 76 xs bent between the slots 32 whose slot numbers are 35 and 36, so that the angle between the tooth 76 and the rear section 140 is reduced, and the same applies to the half tooth 88. This shaping process is continued until, finally, the tooth 76 is bent between the slots 32 whose slot numbers are 3 and 4, with respect to the tooth 76 between the slots 32 .whose slot numbers are 2 and 3. Before completion of the process of bending the core 24 around, however, the three winding overhangs 115 of the three phases 93, . 96 and 99 must, first of all, be inserted into the slots 32 whose slot numbers are 3, 2 and 1. To do this, the individual winding overhangs 115 are inserted or pushed by means of a respective die 126 into the slots 32 whose slot numbers are 3, 2 and 1. In one version, this is also feasible for the winding overhangs 115 by means of an individual die 127, see also Figure 10. Instead of lining a slot 32 with an insulating layer 123 before the insertion of a pressed winding side 36 and the subsequent closing of the slot by means of a slot closure sheet 124, see also Figure 11, in one version it is also possible to fit the dies 126 and 127 with slot closure sheets 124, so that the slot closure sheets 124 can be pushed into the slots 32 at the sair^e time as the winding overhangs 115. Their position in the slots 32 is then likewise secured by means of the slot openings 72, which become narrower during the process of bending the core 24 around, under the tooth strips 84, Yet another version likewise provides for two-part slot insulation to be used, comprising an insulating layer 123 and a slot closure sheet 124. In this case, the already pressed core winding 40 and its winding sides 36 are placed onto the sides with the insulating layer 123 before being inserted into the core 24, and if necessary are bonded, and will later be located in the slot base. The slot closure sheet 124 is pushed into the slots 32 with the winding overhangs 115, in the same way as before by means of the dies 126 and 127, which are fitted with slot closure sheets 124. A further version provides for the pressed winding sides 36 to have an integral insulating layer 123 placed on them before they are inserted into a slot 32, Fiaure 12. In the exemplary embodiment illustrated th' re, the insulating layer 123 is placed on the win.""^ng side 36 such chat two ends 130 of the insulating layer 123 overlap, and are bonded between the two mutually adjacent surfaces of the ends, in this version, the entire core winding 40 is not inserted into the slots 32 in the core 24 until the insulating layer 123 has been placed on the winding sides 36, Figure 13. . Figure 14 shows a simple lap winding in three-dimensional form, This lap winding once again represents the first phase 93 of a core winding 40. As before in the case of the two-layer lap winding shown in Figure 3 and Figure 4, the winding process starts from a position of a slot 32 whose slot number is 1, so that a first lap is wound into the slots 32 whose slot numbers are 1 and 4, and further coils are finally arranged in steps of three with respect to the distances between the sloes. The first phase 93 finally ends with the end X in the slot 32 whose slot number i 34. A correspondingly constructed second phase 96 is placed over the first phase 93 in order to form a core winding 40 starting at a slot 32 whose slot number is 2 and continuing to a slot 32 whose slot number is 35. The same applies to a third phase 99, -starting in the slot whose number is 3, and continuing to the slot whose slot number is 36. A core winding 40 formed in such a way has no overall winding overhang 102. Figure 15 shows a core 24 with 72 slots. Here, a first phase 93, starting from a slot 32 whose slot number is 1, is wound into the slots 1 and 7, in order to be wound around the slots 2 and 8 after a specific number of turns. Finally, once this second coil has been wound into the slots 13 and 19, a further coil is then wound, with coil connecting wire, is wound, into the slots 14 and 20, and so on until, finally, after a total of eight further coils, the wire from the phase winding 93 in the slot whose number is 68 is passed out of the core 24 once again. The second phase 96 is started in the slot 32 whose slot number is 3, in order to pass the wire of the second phase 96 out of the core 24 once again in the slot whose number is 70. The winding of the third phase 99 starts in the slot whose number is 5, and ends in the slot whose number is 72. Figure 16 shows the first phase 93 in the form of a distributed wave winding 135, The wire 91 is passed into the slot 4 via a connecting wire section 107 starting m the slot 32 whose slot number is 1, from where it is once again wound further via a further connecting wire section 107 into the slot 7, as shown in Figure 16, until a first winding overhang 115 is produced in a position corresponding to the slot 1. From there, it is wound back via the slots 34 to 4, A second phase winding 9 6 is wound in an analogous manner, starting from the slot 2 and continuing to the slot 2, and a winding overhang 115 that is formed there being wound back again to the slot 5, and a third phase being wound, starting in the slot 3, as far as a winding overhang 115 in the slot 32 whose slot number is 3, and from there back again into the slot 32 whose slot number is 6. A core 24 having a core winding 40 in the form of such a distributed wave' winding 35 is likewise suitable for the method according to the invention. In a further exemplary embodiment, the core 24 is provided first of all. The winding 40 is now wound into the slots 32 using the wire 91, or a prefabricated winding 40 is inserted into the slots 32. In this case, the winding 4 0 has not yet been pressed. Then, with slot sides 170 of a slot 32 in each case aligned, a guide element 173 is placed onto that side 28 of the core 24 which v;ill later point radially inwards, so that a constant distance is produced between the guide 6lements 173. A die 176 with an internal contour 179 is then moved towards the winding side 115, guided by the two guide elements 173. The individual slot wire sections 105 of the winding side 115 are in the process forced into the internal contour 179, and are shaped such that the cross sections of the winding sides 115, after the shaping process, correspond to the cross section of a slot 32 after the core 24 has been bent around, Figure 17A, 17B. Alternatively, it is also possible in each case to press individual slot wire sections 105, which are each wound in one slot 32, successively. Before the winding 40 is wound in or inserted, an insulating layer 123 may firstly be introduced, depending on the requirement. After the shaping process, the die 176 is once again removed from the slot 32, and the guide elements 173 are lifted off the core 24, Figure 17C. This core 24 with the winding 40 is then processed in the further method steps, as shown in Figure 9 or 10 and as described with respect to those figures. A further exemplary embodiment provides' for wire 91 to be used whose largest cross-sectional dimension is greater than the width of the slot opening 72 in the circumferential direction of the core 24 when it is still in the cuboid shape 20. If such ,a winding is wound with an endless wire 91, for example wire 91 with a rectangular wire cross section, as is used for windings that are referred to as bar windings, and as is done with the three winding configurations already described, insertion of the core winding 40 is intrinsically impossible. In order to overcome this, the core 24 is bent over its rear surface 60, before the insertion of the core winding 40, such that the slot openings 72 are widened and the core winding 40 can be inserted. As already described, once the core winding 40 has been inserted, the core 24 together with the core winding 4 0 is also then bent around in this case, with the slot openings 72 being narrowed further, see Figure 18B. In comparison to conventional bar windings, which often have twice as many welded or soldered circuit connections as there are slots 32, the complexity of producing circuit connections is restricted to the wire ends U to Z, The exemplary embodiment shown in Figures 18A and 18B is not restricted to the use of wires with the corresponding cross-sectional dimensions. In fact, it also applies to core windings 40 with winding sides 36 which are pressed such that, because of their width, they cannot be inserted into the slot.. opening 72. in the circumferential direction, but only once the slot opening has been widened after the core 2 4 has been bent over its rear surface 60. In order to improve the dimensional stability of the pressed winding sides 36, a stove enamel can be used to fix The winding sides 36. This can be done, for example, by using a wire 91 which has. already been treated with such an enamel and whose enamel coating is heated in the pressing tool 44 and assumes at least a sticky, viscous state, so that: the wires 91 can adhere to one another and are firmly connected to one another after cooling down and solidification, and can easily be processed further. The electrically effective slot filling factor is in this case defined as the cross-sectional area ratio of the sum of all the cross sections of the electrically effective part of the slot wire sections 105 arranged in a slot 32, with respect to the cross section of the slot 32 after the bending-around process. The invention provides for an electrically effective slot filling factor of at least 55% to be achieved. This lower limit represents a minimum requirement for the electrical effectiveness. However, an upper limit of 75% is technically still feasible. A higher slot filling factor leads to such high forces during the pressing of the winding sides 3 6 that any enamel coating on the wires 91 is damaged, so that short circuits in the core winding 40 make it unusable. A slot filling factor in a range between 57% and 70% provides a good compromise taking account of production tolerances and a technical feasibility. Figure 19A shows a stator 150 comprising a core 24 formed from laminates 153 and with a single lap winding as the core winding 40. Figure 18B shows a joint 156, formed from the two end surfaces 68 of the bent-around core 24 being placed against one another. In order to prevent the bent-around core 24 from being able to spring apart due to the elastic element of the bending process, a welded seam 160 is applied to Che joint 156, in order to firmly connect the two ends 61 of the core 24 to one another. Figure 20 shows a symbolic illustration of an electrical machine 140 having the stator- 150 according to the invention. 1. Method for producing a core (24) which can be excited magnetically and has a core winding (40) for an electrical machine, according to which, in a method step (SI) , the one core (24) is produced which essentially has a cuboids shape (20) with slots (32) running parallel on one side and in whose slots (32) , in a method step (S2), the winding sides (3G) of the " core winding (40) are inserted and then,' in a method step (S3), the core (24) together with the core winding (40) is formed into a cylindrical annular shape (52) with slots (32) pointing radically inwards, characterized in that all the winding sides (36), which are inserted into a respective slot (32), are each pressed and formed in a tool (44) into a slot shape (119) before being inserted into the slot (32) . 2. Method according toClaim 1, characterized in that Chew core (24) is manufactured such that a half tooth (88) is formed in the circumferential direction on each of its ends (61) which are to be joined to one another. 3. Method according to one of the preceding claims, characterized in that the winding sides (36) of the core winding (40) are pressed into a slot shape (119) which corresponds to the cross-sectional shape of the slots (32) and of the core (24). 4. Method according to Claims 1 and 2,, characterized in , that the winding sides (36) of the core winding (40) are pressed into a slot shape (119) which corresponds to the cross-sectional shape of the slots (32) of the core (24) minus at least one element with the thickness (disso) of an insulating layer (123) . 5. Method according to one of the preceding claims, characterized in that' the core winding (40) is wound with at least one winding overhang (115) . 6. Method according to Claim 5 characterized in that the distance (d2) between an overhanging winding" side (36) and an adjacent winding side (36} which is not overhanging is wound such that it is greater than the distance (dl) between two slots (32). , >,. 7. Method according to Claim 6, characterized in that the pressing of the winding sides (36) into the slot shape (119) results in the at least one overhanging winding side (36) being permanently raised out of a plane formed by the winding sides (36) which are not overhanging. 8. Method according to one of the preceding claims, characterized in that the core winding (40) is in the form of a two-layer lap winding. 9. Method according to one of the preceding claims, characterized in that, before the insertion of the core winding (40) into the slots (22), the core back (89) of the core (24) is bent such that slot openings (72) are widened for insertion of the winding sides (36). 10. Method according to one_ of the preceding Claims 1 to 4, characterized in that the core winding (40) is in the form of a single, single-layer lap winding. 11. Method according to one of the preceding Claims 1 to 9, characterized in that a winding overhang (115) is V. inserted into the at least one slot (32) before completion of the process of bending the core (24) into the cylindrical annular shape (52). 12. Method according to one of the preceding claims, characterized in that, once the core (24) has been bent into the cylindrical annular shape (52), the ends (61) are connected to one another by techniques such as welding, soldering or bonding. 13. Method for producing a core (24) which can be excited magnetically has a core winding (40) for an electrical machine, according to which, in a method step (SI) , the theca core (24) is produced which essentially has a cuboids shape (20) with slots (32) running parallel ore one side and in whose slots (32), in a method step (S2), the winding sides (36) of the core winding (40) are inserted and then, in a method step (S3), the core (24) together with the core winding (40) is formed into cylindrical annular shape (52) with slots (32) ' pointing radically inwards, characterized in that all the winding sides (36) which are each inserted >^^° ^ slot (32) are each shaped by means of a die (176) once they have been inserted into the slot (32), such that all the winding sides are shaped overall such that their external contour corresponds to a slot (32) in the bent-around core (24) . 14,/ Core (24) which 'can be excited magnetically and has a core wending (40) for an electrical machine (l40) produced according to one of the preceding claims, 15. Core (24) which can be excited magnetically and has/ a core winding (40)for an electrical machine (14 0) according to 'claim 14 characterized in that the core (24) has a joint (156) at which its two end surfaces (68) are connected to one another. 16. Core (24) which can be excited magnetically and has a core winding (40)for an electrical machine (140) according to Claim 14 or 15, characterized in that the two ends (61) are connected to one another by techniques such as welding, soldering or bonding. 17. Core (24) which can be excited magnetically and has a core winding (40) for an electrical machine (140) according to one of Claims 14 to 16, characterized in that at least one core winding connection is arranged on each of the two sides of the joint (156). 18. Stator (150) torr an electrical machine (140), which is a core (24) which is produced according to one of the preceding Claims 14 to 17, can be excited magnetically and has a core winding (40). 19. Electrical machine (140), in particular" a generator, having stator (150) according to Claim 18. 20. Method for producing a core substantially as herein described with reference to the accompanying drawings. 21. Stator for an electrical machine substantially as harem described with reference to the accompanying drawings. 22. Electrical machine substantially as herein described with reference to the accompanying drawings.

Full Text

Method for producing a core which can _ be excited magnetically and has a core winding for an electrical machine, a core which can be excited magnetically, is produced using the method and has a core winding, and an electrical machine having a core which is produced using the method and has a core winding
Prior art
A production method for the stator of an electrical
machine according to theprecharacterizing clause of
Claim 1 is already known from Japanese Laid-open
Specification 5-103 052.
In order to produce this stator, individual sheet-metal laminates are first of all stamped out, and a specific number of these sheet-metal laminates are formed into layers superimposed one on top of the other until the desired axial width of the core is achieved. These sheet-metal laminates formed into layers form the stator core, which thus has chew normal teeth and slots, aligned parallel to one another, on one side for a stator. An already pre-wound core winding, which is in the form of a distributed wave winding, is provided in an approximately planar form, and is then inserted into the slots in the essentially flat core. The flat assembly comprising the core and core winding has what is referred to as a winding overhang, that is to say each individual one of the total of three phases has a winding side which is initially not inserted into slots. This assembly comprising the core and core winding is then bent around so as to produce a conventional, hollow-cylindrical stator. In the process, the overhanging winding sides must finally be inserted into the corresponding slots before completion of the stator.
As a result: of this production process, the core has two ends which must be placed flush against one another

when the core together with the core winding is bent around. These two ends are geometrically placed into the slot base of one core slot.
This prior art has the disadvantage that, despite the good access to the slots, the filling level is not optimum.
Advantages of the invention
The invention is based on the knowledge that the slots, which are widened before the laminated core is bent around, must be filled such that the inserted winding corresponds at least approximately to the shape of the slots after the bending-around process, even before said bending-around process is carried out, with a certain amount of compression within the inserted winding invariably being desirable.
The method according to the invention for producing a core for an electrical machine therefore provides that, before they are inserted into the slots in the core, all the winding sides of the core winding are pressed and shaped into a slot shape in a tool. This is a highly advantageous measure since relatively high slot filling factors of 55% or more are thus achieved. This prevents the prefabricated assembly comprising the flat core and core winding from having to absorb the forming work while being bent around into the hollow-cylindrical shape, and the core thus being unacceptably deformed.
The measures described in the dependent claims relate to advantageous developments and improvements of the method according to the main claim.
A further refinement of the invention provides that a half tooth is in each case formed in the circumferential direction at both ends of the core,

which are to be connected to one another in a subsequent step, that is to say the abutting edges of the laminated core are not located, in the known manner, in a slot, but within a tooth surrounding the

slots. Although this measure makes it harder to connect the abutting edges, but, if a coil with a winding overhang is inserted into the core, then this winding overhang must be inserted into 9 slot shortly before the completion of the process of bending the core or the stator around. If this slot has now' already been completely finished, there is no risk of this winding side of the winding overhang being jammed in between the two ends at the abutting edges. This reliably prevents destruction of this final winding side to be inserted, in particular in the case of a manufacturing process which is being carried out quickly, in a simple manner. Furthermore, it avoids any slot insulation which is placed around the final winding side to be inserted sliding down from this winding side while said winding side is being inserted and, in consequence, at least prevents the manufacturing process from being impeded. A further advantage of a half-formed tooth in each case is that the magnetic reluctance in the magnetic return path of the stator core is not interrupted, and magnetic losses are thus reduced.
Once the core winding has been manufactured, the individual coil or lap sides occupy an envelope area which is generally larger than the actual slot area once the core has been bent around. If the winding sides are in each case pressed into a slot shape in a tool, which corresponds to the final shape of the slot in the core, before being inserted into the core, the winding sides are deformed, and the envelope area of the winding sides is matched to the actual slot area once the stator or core has been bent around. This thus avoids the individual teeth of the core exerting deformation forces on the winding sides, and in consequence possibly being bent themselves, while the

stator is being bent around, that is to say the core together with the core winding, since this could possibly destroy the core. If the slot shape in the tool takes account of at least a proportion of the thickness of an insulating layer by the slot shape in the tool being reduced in size by such a proportion on the circumference of the slot shape, the winding sides are then generally pushed lightly between two teeth by the insulating layer. The winding sides and/or the core winding are thus held in a slightly damped manner in their position, with possible oscillations of the winding sides being damped, thus avoiding any varnish layer of the coil wires from being scraped off and, finally, avoiding any possible short circuit,. The insulating layer remains undamaged in particular if the entire thickness of the insulating layer is taken into account by reducing the size of the slot shape of the tool by the entire thickness of the insulating layer in comparison to the slot shape of the core slots.
If a core winding is wound with a winding overhang, then this results in a very largely symmetrical structure for the two end windings at both ends of the stator core. The end windings then have no approximately wedge-shaped cutout in particular in the region of the abutment point, with such a cutout representing a through-opening which could lead to an increased noise level when air flows through it. The symmetrical structure of the end windings achieved by the winding overhang also leads to the bending resistance of the assembly, which is formed from the core and the core winding, being very largely constant over the length and circumference of the stator. The complete assembly, bent into a cylindrical annular shape and comprising the core and core winding is thus particularly accurately round.
If the core winding has at least one overhanging winding side, and if the distance between this at least

one overhanging winding side and the closest winding side which is not overhanging is greater than the distance between two adjacent slots, then this makes it easier to insert the overhanging winding side into the first slot before completion of the process of bending the core around, thus avoiding tensile loads between the overhanging winding side and the last winding side located in the last slot. If, when the winding sides are being pressed into the slot shape, the at least one overhanging winding side is lifted out of the plane which define [sic] the winding sides which are not overhanging, then during the bending-around process and, finally, the insertion of the overhanging coils, this avoids the winding sides from colliding with the end of the core, and possibly being damaged.
A core winding in the form of a two-layer lap winding has the advantage that each lap of a phase winding firstly has wires on the inner circumference and hence in the tooth head area, and secondly has wires in the area of the slot base. Since the cooling of the end windings is generally better on the inner circumference than on the outer circumference, this in the end results in uniform cooling of a lap, and hence also of an entire phase winding. In consequence, not only is one phase winding uniformly cooled, but also the entire core winding. Each individual phase winding can be designed for the same load.
If the core winding is designed as a simple, single-layer lap winding, the core winding has no overhanging winding sides, there are no overhanging winding sides needing to be inserted when the assembly comprising the core and core winding is being bent around, and the bending-around process into the annular circular shape can be carried out easily and without any problems, without any overhanging winding sides.

In a further refinement of the invention, the core which is provided is bent forward to a certain extent about its core back, that is to say about the side which is not in a slot, before the insertion of the core winding into the slots, so that the slot openings are widened for insertion of the winding sides. This method step makes it possible to insert windings with winding sides which are broader than the slot opening into the core with very small slot openings in the core when it is still flat. This allows compar;atively broad configurations of the tooth heads and hence a very good transfer of the magnetic field from 9 rotor to the core, which considerably improves the efficiency. This method step also makes it possible to use wires whose smallest cross-sectional dimensions are larger than the width of the slot opening when the stator core is still in the flat state, and wires which have a cross section that is not round.
If the winding overhang is inserted into the at least one slot before completion of the process of bending the core into the cylindrical annular shape, and the bending process is not completed until this has been done, the slot opening is broader than when the core has been completely bent, thus making it easier to insert the winding overhang.
In order to prevent the core which has been bent into the cylindrical annular shape from no longer being deformed back through the elastic element of the bending process, the invention provides for the ends of the core to be connected to one another by techniques such as welding, soldering or bonding.
Drawings
The invention will be explained in more detail in the following text using exemplary embodiments and with reference to the attached drawings, in which:

Figure 1 shows the method sequence for producing the
core according to the invention, with the core winding,
Figure 2 shows a side view of a core having a cuboid
shape, and a plan view of a core winding with the core
winding connections and their association with slots in
the core,
Figure 3 shows a three-dimensional illustration of one
phase of a two-layer lap winding,
Figure 4 shows a schematic combined view of all three
phases of the core winding, formed from a two-layer lap
winding as shown in Figure 3,
Figure 5 shows details of a winding overhang of the
winding shown in Figure 4,
Figure 6A shows a cross section of a winding side
immediately after being wound,
Figure 6B shows a winding side as in Figure 6A in a
pressing tool after a pressing process,
Figure 6C and Figure 6D show details of the contour of
a lap side after pressing.
Figure 7 shows the winding overhang and its position
with respect to the closest winding sides which are not
overhanging,
Figure 8 shows a cross section of a slot with a winding
side inserted, before the bending-around process,
Figure 9 shows a detail of a side view of the core when
it has been virtually completely bent around, with an
auxiliary apparatus for pushing the overhanging coils
into the-slots 1 to 3,
Figure 10 shows a version of the apparatus shown in
Figure 9 for pushing the overhanging coils into the
slots 1 to 3,
Figure 11 shows a cross-sectional view of a slot after
the bending-around process,
Figure 12 shows a further exemplary embodiment relating
to insulation of one winding side,
Figure 13 shows a detail of a winding side, insulated
as shown in Figure 12, in a slot,
Figure 14 shows a three-dimensional view of a single
phase of a simple, single-layer lap winding,

Figure 15 shows a core winding in a cuboid core, formed
from a three-phase, single-layer, simple lap winding,
Figure 16 shows a simple exemplary embodiment of a
distributed wave winding.
Figures 17A, 17B and 17C show a further exemplary
embodiment of a manufacturing method.
Figure ISA shows a detail of a core with a bent-up slot
and an inserted winding side,
Figure 18B shows a detail of the slot shown in Figure
17A, once the core has been bent around,
Figure 19A shows a core with a core winding after the
end of its manufacturing process,
Figure 19B shows a detail of the core with a core
winding in the area of the joint,
Figure 20 shows an electrical machine having a core
according to the invention, with a core winding.
Description of the exemplary embodiments
Figure 1 shows a schematic sequence of the method
according to the invention, with the major steps. A
core 24 which essentially has a cuboid shape 20 and can
be excited magnetically is provided in a method step
SI, see also Figure 2. The core 24 has parallel-running
slots 32 on one side 28.
A core winding 40 has slot wire sections 105, which are
arranged later in the slots 32. The slot wire sections
105 which are to be arranged in the slots 32 and are
combined to form a group are referred to as winding
sides 36. The core winding 40, which has winding sides
36; is pressed in a pressing tool 44 {Figure 6B) such
that the winding sides 3 6 are shaped and are thus
matched to the contour of a slot 32, method step S2. In
a further and subsequent method step S3, the winding

sides 36 of the pressed core winding 40 are inserted
into the slots 32 in the core 24, see also Figure 8,
The core 24 together with the core winding 40 is shaped
into a cylindrical annular sliape 52), with slots 32 pointing radially inwards, in method,step S4 .

Figure 2 shows a side view of the cuboid core 24. The core 24 has a cuboid shape 20 with end surfaces 56 which face away from one another. The end surfaces 56 are connected to one another by means of. a rear surface 60 and a slot surface 64. The two end surfaces 56, the rear surface 60 and the slot surface 64 define a rectangular core cross section; the core 24 has two ends 61, which each have an end surface 68. The core 24 has a total of thirty six slots 32, which are all aligned parallel to one another and are arranged in a common plane. The slots 32 all open in the same direction and end in slot openings 72, which are all located in the slot surface 64. The slots 32 are bounded by teeth 76 with parallel flanks. The teeth 76 have a tooth head 78, which ends in the slot surface 64; and have a tooth foot 80, The tooth feet 80 of the teeth 7 6 all lie in a plane which is arranged parallel to the rear s urface 60. The teeth 75 have a cross-sectional or profiled shape 82, so that the teeth 76 extend parallel to the end surfaces 68. Each tooth head 78 has two tooth strips 84, see also Figure 8, which extend in the circumferential direction when the core 24 has been bent into the cylindrical annular shape 52. Each tooth 76 is formed symmetrically with respect to a tooth centre plane 86, which is oriented parallel to the end surfaces 68. A tooth 38, which is bisected in the tooth centre plane 86, is formed on each of the two end surfaces 68 on the core 24. Thirty-five completely formed teeth 7 6 are arranged between the two half teeth 88, so that a total of thirty-six slots 32 and, when the core 24 is in the bent-around state, thirty-six teeth 76 are produced, with one of the teeth being formed from two bisected teeth 88.
The entire teeth 76 and the half teeth 88 are connected integrally to one another by means of their tooth foot 80 together with a core rear 89. The core rear forms a

magnetic return path for all the entire and half teeth 76 and 88.
The core winding 40 is shown above the core 24, and is illustrated folded through 90 into the plane of the drawing with respect to the core 24. The core winding 40 illustrated in Figure 2 is a three-phase, two-layer lap winding 90. The three-phase lap winding 90, which is wound from coated or varnished wire 91, comprises the first phase 93 with Che connecting wires U and X, the second phase 96 with the core winding connections V and Y, and the third phase 99 with the connecting wires W and Z. The lap winding 90 is inserted with its core winding connection U into a slot 32 whose slot number is 1, the core winding connecting wire Z is inserted into a slot 32 whose slot number is 2, and the core winding connecting wire v is inserted into a slot 32 whose slot number is 3. when the core winding connections U, Z and V together with X, W and Y as well as all the winding sides 3 6 located in between are inserted into the slots whose slot numbers are 1 to 36, this core winding 40 has what is referred to as an overall winding overhang 102, which is initially not inserted into slots 32 when the core winding 40 is inserted into the core 24.
Figure 3 illustrates the first phase 93 from Figiare 2 in a version which is in principle the same. The first phase 93 comprises, in the same way as the other two phases as well, slot wire sections 105 and connecting wires 107 connecting these respective slot wire sections 105, The numbers 1 to 34, shown underneath the illustration of the first phase 93, indicate which of the slot wire sections 105 are located in or are inserted into which, of the slots whose slot numbers are 1 to 34 or 1.
Figure 4 shows a cross-sectional illustration of all three phases 93, 96 and 99, as shown in Figure 2, but

with the first phase 93 being shown'" "only by way of example. The ' two other phases 96 and 99 are manufactured analogously to this. The numbers 1 to 36 and 3 indicate the slot numbers. Starting from the slot'; 32 whose slot number is 1, a slot wire section 105 is arranged, in a first step, from the phase end U in a position Ul corresponding to the slot 32 whose slot number is 1. The slot wire section 105, Ul is connected to the connecting wire. 107, which is not illustrated but extends to the position of the slot ,32 whose slot number is 4. The winding process is continued with the slot wire section 105, U2. The slot wire section i05, U2 is connected to a further connecting wire 107, whic'n is once again wound with a slot wire section 105, U3 to the position of the slot 32 whose slot number is 1. The winding scheme continues with a further connecting wire 107 to a position in the slot 32 whose slot number is 4
via a slot wire section 105,U4_ from where,
alternately, and as illustrated in Figure 4, continues via connecting wires 107 and slot wire sections,- 105, U5 at the position of the slot 32 whose slot number is 7, and so on step-by-step, as illustrated until finally, it reaches the slot 32 whose slot number is 42, from which the slot wire section 105. U48 is passed out once again, and finally represents the phase end X of the first phase 93. It can clearly be seen that two slot wire sections 105, U45 and U47 are arranged beyond the slot 32 whose slot number is 36, and are later once again inserted into the slot 32 whose slot number is 1, and are thus placed above the slot wire sections 105- U3 and Ul. It can clearly be seen in the illustration' in Figure 4 that the individual slot wire sections 105 are located both in a first layer 110 and in a second layer 112. This applies to all three phases 93, 96 and 99. The first layer 110 will later be located in the interior of the slots 32 and the second layer 112 will later be located in the region of the slot openings 72. Although the illustration of the first phase 93 in Figure 3 differs

from the illustrations in Figure 4 and Figure 2, which is due to the position of the individual slot wire sections 105 in the individual layers, this is, however, irrelevant to the manufacturing method and, finally, is also irrelevant in terms of the electrical effect.
Figure 5 shows, in the form of a detail and enlarged, the area of the winding sides 3 6 which are inserted into the slots 32 whose slot numbers are 34, 35, 36, and the individual winding overhangs 115 of the three phases 93, 96 and 99. A distance dl between a winding side 36 of the second phase 96 and the winding side 36 of the third phase 99 corresponds to the distance between two slots 32 when the core 24 is in the cuboid state, see also Figure 2. The distance between the winding side 36 of the third phase 99 and the individual and first winding overhang 115 of the first phase 93 is annotated d2. This distance indicates the distance between the final winding side 3 6 to be inserted into the core 2 4 before the bending-around process, and the first winding overhang 115 which can no longer be inserted into the flat core 24. The distance d2 is greater than the distance dl. The distance between the individual winding overhangs 115 of the three phases 93, 96 and 99 corresponds to the distance dl.
Figure 6A shov;s the cross section of an individual winding side 36. The cross section of an individual winding side 36 initially consists of the cross sections of individual slot wire sections 105, which are initially arranged to a greater or lesser extent in an unorganized manner within a specific envelope area 118. In this case, more laps or turns have been wound than in the illustration in Figures 3, 4 and 5. As has already been mentioned with regard to Figure 1, the winding sides 36 are shaped in a pressing tool, before being inserted into the slots 32 in the core 24, such

that the envelope area 118 finally matches the slot shape 119 of the pressing tool 44, see also Figure 6B. To do this, the winding side 36 is first of all inserted loosely into the slot shape 119 of the pressing tool 44, as shown by the direction of the arrow in Figure 6B. A die 120 then presses the winding side 36 into the slot shape 119, and in the process plastically deforms the winding side 36 in such a manner that its outermost envelope area IIS permanently assumes the slot shape 119. The slot shape 119 of the pressing tool 44 can thus be designed such that it corresponds to the cross-sectional shape of the slots 32 after the bending process. One version provides for the slot shape 119 to correspond to the slot cross-sectional shape of the slots 32 minus at least a proportion of the material thickness diso of an insulating layer 123, see also Figures 6C and 6D, as well as Figure 8.
If, as illustrated in Figure 4, the core winding 40 is wound with an overall winding overhang 102, then the overall winding overhang 102 is at the same level as the second layer 112. The pressing of the core winding 40 in the pressing tool 44 provides for the overall winding overhang 102 at the same time to be lifted out of the plane formed by the second layer 112. The individual winding overhangs 115 have lower faces, which will later face the first layer 110. These lower faces of the individual winding overhangs 115 are raised beyond the second layer 112 by the pressing process in the pressing tool 44 and lie on a curve K, which is within what will later be the diameter of the core 24, which will later be round.
After the pressing and shaping of the winding sides 36 of the core winding 40, the core winding 40 is inserted together with the winding sides 36 into the slots 32, which are lined with the insulating material 123, Figure 8.

The prefabricated assembly, formed from the core 24, the insulating material 123 and the core winding 44, is shaped in the next method step S4 into a cylindrical annular shape 52 with slots 32 pointing radially inwards. This process starts with the 'half tooth 88, which is adjacent to the slot 32 whose slot nuinber is 36. The half tooth 88 is bent in a tool with respect to the closest tooth 76 between the slots 32 whose slot numbers are 35 and 36, so that the tooth heads 7 8 become closer to one another and the slot openings 72 are reduced in size. In the process and at the same time, a rear section 140 between the half tooth 88 and the tooth 76 xs bent between the slots 32 whose slot numbers are 35 and 36, so that the angle between the tooth 76 and the rear section 140 is reduced, and the same applies to the half tooth 88. This shaping process is continued until, finally, the tooth 76 is bent between the slots 32 whose slot numbers are 3 and 4, with respect to the tooth 76 between the slots 32 .whose slot numbers are 2 and 3.
Before completion of the process of bending the core 24 around, however, the three winding overhangs 115 of the three phases 93, . 96 and 99 must, first of all, be inserted into the slots 32 whose slot numbers are 3, 2 and 1. To do this, the individual winding overhangs 115 are inserted or pushed by means of a respective die 126 into the slots 32 whose slot numbers are 3, 2 and 1. In one version, this is also feasible for the winding overhangs 115 by means of an individual die 127, see also Figure 10.
Instead of lining a slot 32 with an insulating layer 123 before the insertion of a pressed winding side 36 and the subsequent closing of the slot by means of a slot closure sheet 124, see also Figure 11, in one version it is also possible to fit the dies 126 and 127 with slot closure sheets 124, so that the slot closure

sheets 124 can be pushed into the slots 32 at the sair^e time as the winding overhangs 115. Their position in the slots 32 is then likewise secured by means of the slot openings 72, which become narrower during the process of bending the core 24 around, under the tooth strips 84, Yet another version likewise provides for two-part slot insulation to be used, comprising an insulating layer 123 and a slot closure sheet 124. In this case, the already pressed core winding 40 and its winding sides 36 are placed onto the sides with the insulating layer 123 before being inserted into the core 24, and if necessary are bonded, and will later be located in the slot base. The slot closure sheet 124 is pushed into the slots 32 with the winding overhangs 115, in the same way as before by means of the dies 126 and 127, which are fitted with slot closure sheets 124. A further version provides for the pressed winding sides 36 to have an integral insulating layer 123 placed on them before they are inserted into a slot 32, Fiaure 12. In the exemplary embodiment illustrated th' re, the insulating layer 123 is placed on the win.""^ng side 36 such chat two ends 130 of the insulating layer 123 overlap, and are bonded between the two mutually adjacent surfaces of the ends, in this version, the entire core winding 40 is not inserted into the slots 32 in the core 24 until the insulating layer 123 has been placed on the winding sides 36, Figure 13. .
Figure 14 shows a simple lap winding in three-dimensional form, This lap winding once again represents the first phase 93 of a core winding 40. As before in the case of the two-layer lap winding shown in Figure 3 and Figure 4, the winding process starts from a position of a slot 32 whose slot number is 1, so that a first lap is wound into the slots 32 whose slot numbers are 1 and 4, and further coils are finally arranged in steps of three with respect to the distances between the sloes. The first phase 93 finally

ends with the end X in the slot 32 whose slot number i 34. A correspondingly constructed second phase 96 is placed over the first phase 93 in order to form a core winding 40 starting at a slot 32 whose slot number is 2 and continuing to a slot 32 whose slot number is 35. The same applies to a third phase 99, -starting in the slot whose number is 3, and continuing to the slot whose slot number is 36. A core winding 40 formed in such a way has no overall winding overhang 102. Figure 15 shows a core 24 with 72 slots. Here, a first phase 93, starting from a slot 32 whose slot number is 1, is wound into the slots 1 and 7, in order to be wound around the slots 2 and 8 after a specific number of turns. Finally, once this second coil has been wound into the slots 13 and 19, a further coil is then wound, with coil connecting wire, is wound, into the slots 14 and 20, and so on until, finally, after a total of eight further coils, the wire from the phase winding 93 in the slot whose number is 68 is passed out of the core 24 once again. The second phase 96 is started in the slot 32 whose slot number is 3, in order to pass the wire of the second phase 96 out of the core 24 once again in the slot whose number is 70. The winding of the third phase 99 starts in the slot whose number is 5, and ends in the slot whose number is 72.
Figure 16 shows the first phase 93 in the form of a distributed wave winding 135, The wire 91 is passed into the slot 4 via a connecting wire section 107 starting m the slot 32 whose slot number is 1, from where it is once again wound further via a further connecting wire section 107 into the slot 7, as shown in Figure 16, until a first winding overhang 115 is produced in a position corresponding to the slot 1. From there, it is wound back via the slots 34 to 4, A second phase winding 9 6 is wound in an analogous manner, starting from the slot 2 and continuing to the slot 2, and a winding overhang 115 that is formed there being wound back again to the slot 5, and a third phase

being wound, starting in the slot 3, as far as a winding overhang 115 in the slot 32 whose slot number is 3, and from there back again into the slot 32 whose slot number is 6. A core 24 having a core winding 40 in the form of such a distributed wave' winding 35 is likewise suitable for the method according to the invention.
In a further exemplary embodiment, the core 24 is provided first of all. The winding 40 is now wound into the slots 32 using the wire 91, or a prefabricated winding 40 is inserted into the slots 32. In this case, the winding 4 0 has not yet been pressed. Then, with slot sides 170 of a slot 32 in each case aligned, a guide element 173 is placed onto that side 28 of the core 24 which v;ill later point radially inwards, so that a constant distance is produced between the guide 6lements 173. A die 176 with an internal contour 179 is then moved towards the winding side 115, guided by the two guide elements 173. The individual slot wire sections 105 of the winding side 115 are in the process forced into the internal contour 179, and are shaped such that the cross sections of the winding sides 115, after the shaping process, correspond to the cross section of a slot 32 after the core 24 has been bent around, Figure 17A, 17B.
Alternatively, it is also possible in each case to press individual slot wire sections 105, which are each wound in one slot 32, successively.
Before the winding 40 is wound in or inserted, an insulating layer 123 may firstly be introduced, depending on the requirement.
After the shaping process, the die 176 is once again removed from the slot 32, and the guide elements 173 are lifted off the core 24, Figure 17C.

This core 24 with the winding 40 is then processed in the further method steps, as shown in Figure 9 or 10 and as described with respect to those figures.
A further exemplary embodiment provides' for wire 91 to be used whose largest cross-sectional dimension is greater than the width of the slot opening 72 in the circumferential direction of the core 24 when it is still in the cuboid shape 20. If such ,a winding is
wound with an endless wire 91, for example wire 91 with a rectangular wire cross section, as is used for windings that are referred to as bar windings, and as is done with the three winding configurations already described, insertion of the core winding 40 is intrinsically impossible. In order to overcome this, the core 24 is bent over its rear surface 60, before the insertion of the core winding 40, such that the slot openings 72 are widened and the core winding 40 can be inserted. As already described, once the core winding 40 has been inserted, the core 24 together with the core winding 4 0 is also then bent around in this case, with the slot openings 72 being narrowed further, see Figure 18B.
In comparison to conventional bar windings, which often have twice as many welded or soldered circuit connections as there are slots 32, the complexity of producing circuit connections is restricted to the wire ends U to Z,
The exemplary embodiment shown in Figures 18A and 18B is not restricted to the use of wires with the corresponding cross-sectional dimensions. In fact, it also applies to core windings 40 with winding sides 36 which are pressed such that, because of their width, they cannot be inserted into the slot.. opening 72. in the circumferential direction, but only once the slot opening has been widened after the core 2 4 has been bent over its rear surface 60.

In order to improve the dimensional stability of the pressed winding sides 36, a stove enamel can be used to fix The winding sides 36. This can be done, for example, by using a wire 91 which has. already been treated with such an enamel and whose enamel coating is heated in the pressing tool 44 and assumes at least a sticky, viscous state, so that: the wires 91 can adhere to one another and are firmly connected to one another after cooling down and solidification, and can easily be processed further.
The electrically effective slot filling factor is in this case defined as the cross-sectional area ratio of the sum of all the cross sections of the electrically effective part of the slot wire sections 105 arranged in a slot 32, with respect to the cross section of the slot 32 after the bending-around process. The invention provides for an electrically effective slot filling factor of at least 55% to be achieved. This lower limit represents a minimum requirement for the electrical effectiveness. However, an upper limit of 75% is technically still feasible. A higher slot filling factor leads to such high forces during the pressing of the winding sides 3 6 that any enamel coating on the wires 91 is damaged, so that short circuits in the core winding 40 make it unusable. A slot filling factor in a range between 57% and 70% provides a good compromise taking account of production tolerances and a technical feasibility.
Figure 19A shows a stator 150 comprising a core 24 formed from laminates 153 and with a single lap winding as the core winding 40. Figure 18B shows a joint 156, formed from the two end surfaces 68 of the bent-around core 24 being placed against one another. In order to prevent the bent-around core 24 from being able to spring apart due to the elastic element of the bending process, a welded seam 160 is applied to Che joint 156,

in order to firmly connect the two ends 61 of the core 24 to one another.
Figure 20 shows a symbolic illustration of an electrical machine 140 having the stator- 150 according to the invention.

1. Method for producing a core (24) which can be
excited magnetically and has a core winding (40) for an
electrical machine, according to which, in a method
step (SI) , the one core (24) is produced which
essentially has a cuboids shape (20) with slots (32)
running parallel on one side and in whose slots (32) ,
in a method step (S2), the winding sides (3G) of the
" core winding (40) are inserted and then,' in a method step (S3), the core (24) together with the core winding
(40) is formed into a cylindrical annular shape (52) with slots (32) pointing radically inwards, characterized in that all the winding sides (36), which are inserted into a respective slot (32), are each pressed and formed in a tool (44) into a slot shape
(119) before being inserted into the slot (32) .
2. Method according toClaim 1, characterized in that Chew core (24) is manufactured such that a half tooth (88) is formed in the circumferential direction on each of its ends (61) which are to be joined to one another.
3. Method according to one of the preceding claims, characterized in that the winding sides (36) of the core winding (40) are pressed into a slot shape (119) which corresponds to the cross-sectional shape of the slots (32) and of the core (24).
4. Method according to Claims 1 and 2,, characterized in ,
that the winding sides (36) of the core winding (40) are pressed into a slot shape (119) which corresponds to the cross-sectional shape of the slots (32) of the core (24) minus at least one element with the thickness (disso) of an insulating layer (123) .
5. Method according to one of the preceding claims,
characterized in that' the core winding (40) is wound
with at least one winding overhang (115) .

6. Method according to Claim 5 characterized in that the distance (d2) between an overhanging winding" side (36) and an adjacent winding side (36} which is not overhanging is wound such that it is greater than the distance (dl) between two slots (32). , >,.
7. Method according to Claim 6, characterized in that
the pressing of the winding sides (36) into the slot shape (119) results in the at least one overhanging winding side (36) being permanently raised out of a plane formed by the winding sides (36) which are not overhanging.
8. Method according to one of the preceding claims, characterized in that the core winding (40) is in the form of a two-layer lap winding.
9. Method according to one of the preceding claims, characterized in that, before the insertion of the core winding (40) into the slots (22), the core back (89) of the core (24) is bent such that slot openings (72) are widened for insertion of the winding sides (36).

10. Method according to one_ of the preceding Claims 1 to 4, characterized in that the core winding (40) is in the form of a single, single-layer lap winding.
11. Method according to one of the preceding Claims 1 to 9, characterized in that a winding overhang (115) is
V.
inserted into the at least one slot (32) before completion of the process of bending the core (24) into the cylindrical annular shape (52).
12. Method according to one of the preceding claims,
characterized in that, once the core (24) has been bent
into the cylindrical annular shape (52), the ends (61)
are connected to one another by techniques such as
welding, soldering or bonding.

13. Method for producing a core (24) which can be excited magnetically has a core winding (40) for an electrical machine, according to which, in a method step (SI) , the theca core (24) is produced which essentially has a cuboids shape (20) with slots (32) running parallel ore one side and in whose slots (32), in a method step (S2), the winding sides (36) of the core winding (40) are inserted and then, in a method step (S3), the core (24) together with the core winding (40) is formed into cylindrical annular shape (52) with slots (32) ' pointing radically inwards, characterized in that all the winding sides (36) which are each inserted >^^° ^ slot (32) are each shaped by means of a die (176) once they have been inserted into the slot (32), such that all the winding sides are shaped overall such that their external contour corresponds to a slot (32) in the bent-around core (24) .
14,/ Core (24) which 'can be excited magnetically and has a core wending (40) for an electrical machine (l40) produced according to one of the preceding claims,
15. Core (24) which can be excited magnetically and has/
a core winding (40)for an electrical machine (14 0)
according to 'claim 14 characterized in that the core (24) has a joint (156) at which its two end surfaces (68) are connected to one another.
16. Core (24) which can be excited magnetically and has a core winding (40)for an electrical machine (140) according to Claim 14 or 15, characterized in that the two ends (61) are connected to one another by techniques such as welding, soldering or bonding.
17. Core (24) which can be excited magnetically and has a core winding (40) for an electrical machine (140) according to one of Claims 14 to 16, characterized in

that at least one core winding connection is arranged on each of the two sides of the joint (156).
18. Stator (150) torr an electrical machine (140), which
is a core (24) which is produced according to one of
the preceding Claims 14 to 17, can be excited
magnetically and has a core winding (40).
19. Electrical machine (140), in particular" a
generator, having stator (150) according to Claim 18.

20. Method for producing a core substantially as herein described with
reference to the accompanying drawings.
21. Stator for an electrical machine substantially as harem described with
reference to the accompanying drawings.
22. Electrical machine substantially as herein described with reference to
the accompanying drawings.

Documents:

in-pct-2001-1439-che form-5 13-10-2010.pdf

IN-PCT-2001-1439-CHE OTHER PATENT DOCUMENT 13-10-2010.pdf

IN-PCT-2001-1439-CHE AMENDED CLAIMS 13-10-2010.pdf

IN-PCT-2001-1439-CHE AMENDED PAGES OF SPECIFICATION 13-10-2010.pdf

IN-PCT-2001-1439-CHE CORRESPONDENCE OTHERS 21-04-2010.pdf

IN-PCT-2001-1439-CHE EXAMINATION REPORT REPLY RECEIVED 13-10-2010.pdf

in-pct-2001-1439-che form-1 13-10-2010.pdf

in-pct-2001-1439-che abstract.jpg

in-pct-2001-1439-che abstract.pdf

in-pct-2001-1439-che claims.pdf

in-pct-2001-1439-che correspondence-others.pdf

in-pct-2001-1439-che correspondence-po.pdf

in-pct-2001-1439-che description (complete).pdf

in-pct-2001-1439-che form-1.pdf

in-pct-2001-1439-che form-18.pdf

in-pct-2001-1439-che form-26.pdf

in-pct-2001-1439-che form-3 13-10-2010.pdf

in-pct-2001-1439-che form-3.pdf

in-pct-2001-1439-che form-5.pdf

in-pct-2001-1439-che pct.pdf

IN-PCT-2001-1439-CHE POWER OF ATTORNEY 13-10-2010.pdf

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Patent Number

243990

Indian Patent Application Number

IN/PCT/2001/1439/CHE

PG Journal Number

47/2010

Publication Date

19-Nov-2010

Grant Date

12-Nov-2010

Date of Filing

22-Jan-2001

Name of Patentee

ROBERT BOSCH GMBH

Applicant Address

POSTFACH 30 02 20, 70442 STUTTGART

Inventors:

#	Inventor's Name	Inventor's Address
1	KREUZER, HELMUT	HEMANN-ESSIG-STRASSE 9, 71701 SCHWIEBERDINGEN
2	RAU, EBERHARD	STETTINGER STRASSE 27, 70825 KORNTAL-MUENCHINGEN
3	WILLMOTT, ADAM	55 PASTORAL WAN, TYCOCH, SWANSEN SAZ 9LY
4	FUSSEY, ALAN	TY NEYVYOD, SUTTON CANE, 06 MORE BY SEA CF 32 01E
5	NEIL, WILLIAMS	I CAER GIL MLIG, GARTH, BRIDGEND CF34 05D
6	HENNE, MARTIN	PAUL-HINDERMITH-STRASSE 14, 71696 MOEGLINGEN
7	PFLUEGER, KLAUS	SCHLOSSSTRASSE 2, 71735 EBERDINGEN

PCT International Classification Number

H02K15/06

PCT International Application Number

PCT/DE01/00244

PCT International Filing date

2001-01-22

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	10002385.1	2000-01-20	Germany