WO2014186524A1

WO2014186524A1 - Device and method for the production of a coil body for an electric motor

Info

Publication number: WO2014186524A1
Application number: PCT/US2014/038099
Authority: WO
Inventors: Edmund Gassner
Original assignee: Borgwarner Inc.
Priority date: 2013-05-15
Filing date: 2014-05-15
Publication date: 2014-11-20
Also published as: DE112014001874T5

Abstract

The invention relates to a coil body production apparatus for the production of a coil body (13) for an electric motor having a ferromagnetic flux return ring (7) with a grooveless, continuous internal cutout (21) and with an ironless air gap winding composed of multiple individual coils (5), which coil body production apparatus has, for the purposes of optimize production: multiple guide lamellae (5) which are arranged parallel to one another and which have guide lamellae intermediate spaces (6), wherein the guide lamellae (3) can be moved into and out of the grooveless cutout (21) of the flux return ring (7), a stripper (4) for drawing the individual coils (5) into the guide lamellae intermediate spaces (6), wherein the stripper (4) can be moved into the interior of the guide lamellae (3) when the guide lamellae (3) have been moved into the flux return ring (7), such that, in the process, the individual coils (5) can be picked up by the stripper (4) for the purpose of being drawn into the guide lamellae intermediate spaces (6).

Description

DEVICE AND METHOD FOR THE PRODUCTION OF A COIL BODY

FOR AN ELECTRIC MOTOR

Description

This invention relates to a coil body production apparatus for the production of a coil body for an electric motor with an ironless air gap winding composed of multiple individual coils. The invention also relates to a production method for the production of a coil body of an electric motor with an ironless air gap winding.

Electric motors with an ironless air gap winding are characterized in that the winding is not laid around an iron core but rather is in the form of an air-core coil. A coil body of said type may be part of a stator, though may also revolve with the rotating part of the electric motor. Motors are known in which the rotor comprises permanent magnets, and further variants are known in which the stator comprises permanent magnets. In many variants, a stator forms an iron flux return body for the magnetic flux return between different individual coils of the coil body. The coil body may then be mechanically fixedly connected to an iron flux return body of said type. The stator then does not have any grooves on its inner side against which the coil body bears, such that this can be referred to as a motor with a grooveless stator winding. Such motors are in particular direct-current voters. An example of such a motor is presented in CH 604 411.

From EP 0 795 951 Bl, it is known for individual coils which are manufactured at a separate station to be suspended from pins, whereupon the individual coils are drawn by means of the pins into grooves of a stator. During the drawing-in process, said pins draw the individual coils past blade-like coil guides which separate the individual coils from one another. The coil guides are arranged as part of a drawing-in device upstream of the stator core into which the individual coils are drawn. Although the coil guides separate the individual coils before the latter are actually drawn into the stator core, it is however not possible to prevent windings of the individual coils from coming to lie one on top of the other in unordered fashion in the interior of the stator core. This can have an adverse effect on the thickness of the coil body, and can give rise to undesired electrical and magnetic effects. To alleviate said detrimental effects, a sleeve is inserted, the same time as the stripper, into the interior of the coil body to be produced and into the stator core, which sleeve prevents the individual coils from being able to freely move in the direction of the interior of the stator core. Nevertheless, said measure also cannot reliably prevent parts of individual coils from coming to lie one on top of the other as they are drawn into the stator core. Furthermore, the shape of the individual coils as part of the coil body in the stator core may become nonuniform, for example owing to non-uniformities of the wires or owing to bends, which were already present before the drawing-in process, of windings of the individual coils.

The problem addressed by the present invention is that of specifying a device and a method which eliminates at least one of said disadvantages.

The solution to said problem is defined by the features of claims 1 and 9. Said solution gives rise to the advantages that, during the drawing-in process, it is ensured by way of the guide lamellae that windings of the individual coils cannot move into another individual coil. Furthermore, the windings of the individual coils have imparted thereto a reliably defined position and shape.

In particular, for this purpose, it is additionally the case that the spacing between the outer circumference of the stripper and the inner surfaces of the guide lamellae are small enough to prevent a wire from passing through. In order that the guide lamellae can be introduced into the cutout in the flux return ring, a degree of play exists between the radially outwardly directed outer surfaces of the guide lamellae a degree of play with respect to the inner surface of the cutout. The degree of play is small enough to prevent windings from being was a pass from one guide lamellae intermediate space into another guide lamellae intermediate space. The stripper is preferably of tapered form at its end in the drawing-in direction. It is preferable for the external diameter of that section of the stripper which is introduced into the flux return ring to be slightly smaller than the internal diameter of the guide lamellae, such that individual windings of individual coils in one guide lamellae intermediate space cannot jump over two and adjacent guide lamellae intermediate space. In one exemplary embodiment, a part of the stripper may be guided along in the guide lamellae intermediate spaces during the drawing- in process. The guide lamellae are preferably arranged on a guide body, which preferably connects all of the guide lamellae to form one part. It is particularly preferable for the guide body to be of substantially cylindrical form. Here, the guide lamellae may be fastened to the outer circumference of a cylinder, at one axial end of the latter, such that said guide lamellae length in the shell surface of the cylinder. The guide body is preferably provided with a through bore through which the stripper can pass. When the guide lamellae have been drawn into the cutout of the flux return ring, the guide lamellae preferably project beyond the flux return ring. The guide lamellae are preferably longer, as viewed in the axial direction of the cutout, than the axial passage length of the cutout. The expression "grooveless" as a characteristic of the cutout means that no grooves, such as are provided in the case of a conventional, grooved stator of an electric motor, are arranged in the cutout.

The fact that the guide lamellae can be moved into and out of the cutout has the advantage that the guide lamellae can be pulled out of the cutout after the drawing- in process has come to an end. This then yields, in the cutout, a coil body that has individual coils reliably separated from one another. To facilitate the drawing-in process and the movement of the guide lamellae out of the cutout, it is possible for at least parts of the surface of the guide lamellae to have a non-stick coating or to be produced from non-stick material. Polytetrafluoroethylene, or other fluoropolymers, for example, are suitable as a coating material or as material for the guide lamellae.

The flux return ring is typically in the form of a ferromagnetic flux return ring which can conduct the magnetic fields of a stator of an electric motor from one individual coil to another. The flux return ring preferably comprises a soft magnetic sheet material, or ferrite material, for conducting the magnetic field. The flux return ring does not extend through the individual coils. The individual coils, after the production thereof, remain in the interior of the flux return ring. The flux return ring thus forms, for each stator, a respective drawing-in die for the winding thereof.

According to the invention, a coil body production apparatus is proposed in a first aspect, and a method for the production of a coil body is proposed in a second aspect.

The subclaims relate to advantageous refinements of the invention. The coil body production apparatus preferably has a spreading tool. By means of said spreading tool, further shaping of the coil body can be performed after the drawing-in of the individual coils. For this purpose, the spreading tool is introduced into the interior of the coil body and subsequently spread. The cutout of the flux return ring serves as an abutment during this process. It is preferable for the spreading to be performed after the removal of the guide lamellae and the stripper from the cutout in the flux return ring. In this way, it is possible to realize a desired radial thickness of the coil body. This is preferably performed in a state with softened resin. The individual coils are then particularly easily deformable. It is furthermore possible to then wait until the resin has cured, such that a stable coil body is obtained in which the position imparted by the spreading tool is preserved. During a shaping process of the coil body by means of the spreading tool, the coil body is compacted and solidified, such that an altogether more stable coil body is produced.

In one embodiment, the coil body production apparatus has a contacting device. This yields the advantage that the individual coils can be provided with contacts which, after the completion of the production of the coil body, can be used as contacts of a motor that is to be produced. Furthermore, heating current for the softening and curing of resin on the coil wires can be introduced into the individual coils via the contacts. The coil body production apparatus preferably has a holding device for the flux return ring, by means of which holding device the flux return ring can be gripped from the outside. The holding device may have a variable internal diameter, and may be opened and closed in order to hold and release the flux return ring. In particular, the internal diameter of the cutout may be varied by virtue of the flux return ring being surrounded by segments, in particular ring segments, which are arranged so as to be radially displaceable relative to the flux return ring. During the drawing-in process, the flux return ring is subjected to drawing-in forces by the stripper, which drawing-in forces must be dissipated from the flux return ring in order that the latter does not move together with the stripper. The relative drawing- in movement between the flux return ring and the stripper is made possible by means of the holding device. In particular, the holding device is opened when the manufacturing process comes to an end and the finished coil body is to be removed. It is particularly preferable for an automatic coil body production apparatus to be equipped with at least one work table which is movable such that individual coils or a coil body can be transferred from one workstation to a subsequent work station. A translational movement of the work table is conceivable for this purpose, but it is preferable for a rotation to be used. The individual coils may in this case be laid into intermediate spaces between guide lamellae, wherein the guide lamellae are moved from one work station to another. Coil bodies produced from individual coils can be arranged within a flux return ring which is transported from one workstation to another. It is conceivable for not only the coil body but also a stripper that is situated therein to be transported at the same time from one work station to another. In particular, after the transportation process, the stripper is removed from the coil body such that the final shaping of said coil body can be performed, for example by means of a spreading tool. The stripper is then preferably transported back, without a coil body, to the first of the two workstations, preferably to a drawing-in station.

In one embodiment, the stripper may be designed such that one end in the drawing- in direction thereof serves as a winding head expander. For example, after the drawing-in process, the stripper may pierce centrally through the end sections of the individual coils that form the winding head in the drawing-in direction, in order, for example, to create space for a motor shaft which is intended to run through the winding head after the disassembly of the electric motor. During the piercing-through process, the stripper can at the same time be removed from the interior of the coil body. To expand the winding head, it is preferable for the stripper to taper toward its end situated in the drawing-in direction. By means of such a pointed end of the stripper, it is achieved that the internal diameter of the winding head is enlarged, and the winding head is as far as possible not damaged in the process.

In particular, the wires for the individual coils are saturated in resin. These may be pre-saturated wires or, during the winding process, use may be made of a saturation apparatus by means of which a resin is applied to the wires. To fix the coil body, resin that has been applied to coil wires of individual coils can be heated. In the case of many resin types that are typically used, the heating causes said resin to initially soften, before a hardening process then occurs in which the resin becomes chemically cross-linked and hardens. The heating of the resin is typically performed by virtue of a current being conducted through the coil wires, whereby said coil wires heat up owing to their internal resistance. It is preferable for a voltage of at most 44 V to be used for this purpose. The current may be introduced into the coil wires through contacts that have been attached to terminals of the coil wires by the contacting device of the coil body production apparatus. It is preferable for the guide lamellae to be retracted out of the coil body after the latter has been heated and the resin on the coil wires has softened. The guide lamellae can be removed particularly easily at this time. The guide lamellae are normally retracted in the axial direction of the cutout in the flux return ring. When the resin on the coil wires has softened, is preferably furthermore the case that the stripper is removed from the interior of the coil body in the drawing-in direction. In the process, said stripper expands the coil head which protrudes beyond the flux return ring in the drawing-in direction. It is particularly expedient for this to be performed at this time owing to the softening of the resin. An expansion section of the stripper, said expansion section being situated, as viewed in the drawing-in direction, behind the part that is inserted into the flux return ring, may be designed with a diameter that increases counter to the drawing- in direction, and in particular so as to be of conical form. It is accordingly possible, during or after a drawing-in process, for a winding head which forms on that side of the flux return ring from which the drawing-in process is performed to be expanded by means of the expansion section. This may serve in particular to create space for the passage of a rotor through the winding head. The expansion of the winding head may be performed by virtue of the stripper being moved into the flux return ring to such an extent that the increasing diameter on the expansion section forces the winding head outward to an adequate extent. This may be performed in particular after the guide lamellae have been pulled out of the flux return ring.

To impart a desired shape to the winding head, it is conceivable for multiple mould jaws to be moved onto the winding head, for the external diameter of said winding head to be adapted, and for said winding head to be held in said mould until it has hardened after the heating of the resin. Said mould jaws can subsequently be opened in order to permit the removal of the coil body. In one exemplary embodiment, the stripper can be removed from the interior of the coil body after the opening of the mould jaws for the winding head. In the process, the winding ends in the winding head may be pushed further outward. The opening of the gripper orifice of the holding device may take place in the same working cycle. The coil body can then be removed.

If the coil body production apparatus has a winding apparatus, this has the advantage that the coil body production apparatus can be substantially or completely automated. It is alternatively also possible for the individual coils to have their preliminary shape imparted to them outside the coil body production apparatus and to be laid into the guide lamellae intermediate spaces. The winding apparatus preferably has a winding template onto which the individual coils can be blind. The winding template is preferably designed to be adjustable in order to make it possible for individual coils of different sizes to be produced. The winding station is an expanded form of the inlaying station, at which individual coils are wound in addition to the laying of individual coils into guide lamellae intermediate spaces. The individual coils are air-core windings, that is to say they are not wound around a ferromagnetic core. It is preferable for six windings to be laid into the guide lamellae intermediate spaces, which six windings may be provided in particular for a three-phase motor.

Further details, features and advantages of the invention will emerge from the following description and from the appended figures, in which:

Figure 1 shows a central-perspective view of an embodiment of a drawing-in device 1 of a coil body production apparatus according to the invention, shows a schematic plan view of the embodiment of the drawing-in apparatus in Figure 1, with inlaid individual coils, shows a schematic plan view of the embodiment of the coil body production apparatus in Figure 1 in a state in which guide lamellae have been moved in, shows a schematic plan view from Figure 2 with the guide lamellae having been retracted out and a spreading tool having been moved in, and is a schematic, perspective illustration of an embodiment of an automatic coil body production apparatus according to the invention. Figure 1 schematically shows a perspective illustration of a part of a coil body production apparatus, specifically a drawing-in station 1. The drawing-in station 1 in the embodiment shown comprises a flange 2, which in the present exemplary embodiment is in the form of a disk. The flange 2 has an aperture 12 through which a ring of guide lamellae 3 extends. The guide lamellae 3 can, in Figure 1, be pulled downward through the flange 2 and out of the latter. Guide lamellae intermediate spaces 6 are situated between the individual guide lamellae 3. Windings of individual coils 5 are inlaid into said guide lamellae intermediate spaces 6, as can be seen more clearly in Figure la. The flux return ring 7 is arranged, by way of an internal cutout, around the ring of guide lamellae 3 so as to be situated at a distance from the flange, which internal cutout has a clearance fit with respect to outwardly directed surfaces of the guide lamellae 3. The cutout in the flux return ring can be placed onto the outer circumference of the ring of guide lamellae 3 in order to prevent windings from passing from individual coils to other individual coils. A stabilizing device 11 is inserted into the guide lamellae intermediate spaces 6 in at least a part of the region from one end of the guide lamellae 3 to the flux return ring 7, which stabilizing device supports the guide lamellae 3 and ensures that the latter have a defined spacing to one another. The stabilizing device 11 can be removed from the guide lamellae intermediate spaces 6 in the direction of the free end of the guide lamellae 3. As can be clearly seen in Figure la, a part of the inlaid individual coils 5 extends out of the guide lamellae 3 in the interior of the ring. A stripper 4 can be inserted into the interior of the ring of guide lamellae 3 proceeding from the side of the flange 2. Said stripper picks up, in a positively locking manner, those parts of the individual coils 5 which are situated in the interior of the ring of guide lamellae 3, and said stripper draws said parts into the guide lamellae intermediate spaces 6, which are at least partially closed off to the outside by the flux return ring 7. In this way, the individual coils 5 are brought together to form a coil body. As the stripper 4 is moved in, the stabilizing device 11 is pushed out of the guide lamellae intermediate spaces 6. The strip 4 is moved into the interior of the guide lamellae 3 until parts of the individual coils 5 which project out of the flux return ring form a winding head. Those parts of the individual coils 5 which are situated on the flange have then been drawn into the guide lamellae intermediate spaces 6 to such an extent that an end of the coil body on the side of the flange is formed as a second winding head which is arranged below the flux return ring 7. In one exemplary embodiment, the stripper 4 may be pushed all the way through the interior of the guide lamellae 3 until it emerges again at the top end, or said stripper may remain in the interior of the guide lamellae, wherein the stripper 4 and the guide lamellae 3 and the coil body that is produced can be transported to another station of the coil body production apparatus. Alternatively, the stripper 4 may also be pulled out of the ring of guide lamellae 3 again in a downward direction.

Figure la schematically shows a plan view of the drawing-in station 1 which is shown in Figure 1. The flange 2 is not explicitly illustrated, but the individual coils 5 rest, by way of their part that is situated outside the flux return ring 7, on said flange. The individual coils extend from the flange through the guide lamellae intermediate spaces 6 into the interior of the ring of guide lamellae 3. Since, in this example, the individual coils 5 run in each case through two different guide lamellae intermediate spaces 6, this gives rise to in each case one loop, as a part of the individual coils 5, which is situated in the interior of the ring of guide lamellae 3. The flux return ring 7 illustrated in Figure la is first placed on to the ring of guide lamellae 3 once the individual coils 5 have been inlaid into the guide lamellae intermediate spaces 6. The flux return ring 7 may be fixed in its position by means of a holding device 8. In this way, drawing-in forces exerted on the flux return ring 7 can be transmitted into the holding device 8. In this way, the flux return ring 7 remains in its position. The drawing-in process is performed by virtue of the stripper 4 in Figure la being moved out of the plane of the illustration toward the viewer. Said stripper picks up those loops of the individual coils 5 which project into the interior of the ring of guide lamellae 3. Owing to the movement of the stripper 4, the individual coils are drawn into the guide lamellae intermediate spaces 6 and, as the stripper 4 moves onward, said individual coils pass all the way through the guide lamellae intermediate spaces 6, which, at least in sections, are closed off at their outer side by the flux return ring 7. For clarity, not all but only some of the individual coils 5 have been illustrated. Said individual coils extend through in each case one section of the guide lamellae intermediate spaces 6.

Figure 2 shows a cross section through the drawing-in station from Figure 1 , after the drawing-in process has come to an end. The cross sections of cut windings of the individual coils 5 can be seen, by way of example, in some of the lamellae intermediate spaces 6. Said windings have been drawn into the interior of the flux return ring 7 and into the lamellae intermediate spaces 6.

Figure 3 shows a cross section through a shaping station 30. It is conceivable in one variant for the drawing-in station 1 and the shaping station 30 to be combined into one station. The cross section shown in Figure 3 extends through the flux return ring 7, through the coil body 13, which is composed of multiple individual coils, and through a spreading tool 9. The coil body 13 is arranged in the interior of a cutout in the flux return ring 7. The spreading tool 9 is arranged in the interior of the coil body 13. The spreading tool 9 exerts spreading forces, indicated by arrows 14, on the inner circumference of the coil body 13. In this way, said coil body is compacted and has imparted to it a predefined radial thickness 10. Here, the intermediate spaces between the individual coils, in which intermediate spaces the guide lamellae were situated, may be pushed together and eliminated. The individual coils then at least approximately adjoin one another. It is preferable, for the spreading of the spreading tool 9, for a current to be conducted through the individual coils in order to heat the coil wires. Resident applied to the coil wires is thereby softened, such that the spreading process can be performed more easily. Owing to the emerging flow of the softened resin, a continuous conglomerate of resin and windings is formed. After the spreading of the spreading tool 9 and the attainment of the desired thickness of the coil body 10, said position of the spreading tool 9 is maintained until the resin has hardened or, as a result of cooling, has gained adequate strength. Once the coil body 13 exhibits adequate strength, the spreading tool 9 is contracted and removed from the interior of the coil body 13. It is optionally possible for the flux return ring 7 to be held by a holding device 8 during the process.

Figure 4 shows, in a schematic perspective illustration, an automated coil body production apparatus. Said coil body production apparatus comprises a winding station 31, a drawing-in station 1 and a shaping station 30. For the manufacture of a coil body, a wire as starting material initially runs through the winding station 31 , in which the wire is wound to form individual coils. Said individual coils are wound with the aid of a winding template 20 which has coil holding elements 19. The coil holding element 19 can be adjusted in terms of their spacing to one another, such that it is possible to produce coils of different size and thus for different motor power ratings. The coil wire required for the coil winding is, in addition to its electrical insulation, additionally saturated with a resin which, under the action of heat, initially softens and then hardens. The winding station 31 comprises a cylindrical guide body 16, on the free end of which there is arranged a ring of guide lamellae 3 with interposed guide lamellae intermediate spaces. One fully wound individual coil 5 is illustrated suspended into of said guide lamellae intermediate spaces. The guide body 16 is arranged on a rotary table 17. The rotary table 17 is mounted so as to be rotatable about a theoretical axis 18. A further guide body 16 is arranged on the rotary table 17 at the same radius as the guide body 16. The positions of the guide bodies 16 may be interchanged if the rotary table 17 is rotated through 180° about the axis of rotation 18. It is accordingly possible for in each case one guide body 16 to be positioned at the above-described winding station 31 and at a drawing-in station 1. In this way, in the middle coils 5 that are suspended in guide lamellae intermediate spaces at the winding station 31 can be transported from the winding station 31 to the drawing-in station 1.

At the drawing-in station 1 , or even at the winding station 31 , a flux return ring is arranged over the outer circumference of the guide lamellae 3. At the drawing-in station, there is arranged around the flux return ring a holding device 8 which comprises multiple segments which, in the centre thereof, can grip the flux return ring and which are arranged so as to be radially displaceable as viewed from a centre of the ring of guide lamellae 3. In this way, the internal diameter of the holding device 8 can be varied, and the flux return ring held. For the drawing of the individual coils 5 into the guide lamellae intermediate spaces, the flux return ring is arranged around the guide lamellae 3 by being mounted, by way of its cutout, onto the guide lamellae 3 such that the guide lamellae intermediate spaces are closed off radially to the outside. The segments of the holding device 8 are moved onto the outer circumference of the flux return ring in order to hold the latter.

In order to stabilize the guide lamellae 3, there may be mounted onto the free end of side guide lamellae a stabilizing device 11 by means of which the spacings of the guide lamellae 3 are fixed. Furthermore, the stabilizing device 11 supports the guide lamellae 3 such that the latter oscillate less, or not at all. A stripper 4 can be introduced into the interior of the guide body 5 proceeding from the side of the rotary table 17. Said stripper also passes through the interior of the ring of guide lamellae 3. In the process, the stripper 4 carries along those parts of the individual coils 5 which project out of the guide lamellae intermediate spaces into the interior of the ring of guide lamellae. In this way, the individual coils 5 are drawn into the guide lamellae intermediate spaces until the emerge above the flux return ring. During said process, the stabilizing device 11 is removed from the end of the guide lamellae 3. After the drawing-in process, a winding head is formed above the flux return ring.

The holding device 8, which comprises multiple segments, is arranged on a second rotary table 22. The rotary table 22 is mounted so as to be rotatable about a theoretical axis 23. The holding device 8 on the rotary table 22 may be positioned so as to be in alignment with the guide body 5 that can be positioned at the drawing-in station 1 by means of the rotary table 17. The rotary table 22 has a further holding device (not illustrated) which is situated opposite the holding device 8 at the drawing-in station 1, so as to be offset through 180° about the axis of rotation 23, at a shaping station 30. The two holding devices may be interchanged by rotating the rotary table 22, whereby a coil body and a stripper 4 can be transported from the drawing-in station 1 to the shaping station 30. After the drawing-in of the individual coils 5 into the guide lamellae intermediate spaces by means of the stripper 4, the guide body 5 with its guide lamellae 3 is pulled out of the coil body in the axial direction of the coil body. Cavities are formed in the coil body at the locations at which the guide lamellae 3 were previously situated. By means of the holding device 8 divided into segments, the newly formed coil body and the associated flux return ring can remain fixed to the rotary table 22. In particular, the coil body is arranged between the flux return ring and the stripper 4 in the interior of the coil body. By virtue of the fact that the guide lamellae have passed out of engagement with the coil body, the rotary table 22 can now be freely rotated. By means of a rotation through 180°, the coil body with the stripper 4 situated therein is transported to the shaping station 30. At the same time, an empty holding device 8 is transported from the shaping station to the drawing-in station 1, such that a further drawing-in process can take place here. For this purpose, the rotary table 17 is also rotated through 180° such that a guide body 16 with further individual coils 5 is transported from the winding station 31 to the drawing-in station 1. The movements of the rotary tables 17 and 22 preferably take place simultaneously.

At the shaping station 30, contacts 24 are attached, by means of a contacting device which is not illustrated, two terminal points 15 of the coil body, which form contact points in the situation of use in an electric machine. Via said contacts 24, a heating current is introduced into the coils of the winding body in order to heat the latter. At the same time or subsequently, the stripper 4 is pushed out of the coil body in the drawing-in direction. The stripper 4 has a tapering on its end in the drawing-in direction. As the stripper 4 is pushed out of the coil body, said tapering has the effect that the winding head 25 which is situated on the flux return ring in the drawing-in direction is expanded such that the stripper 4 can pass through. This simultaneously has the effect that a shaft of an electric motor with the same diameter as the stripper 4 can pass through the winding head 26. As a result of the heating of the windings, the resin on the windings is softened, such that, during the deformation of the winding head 26, the resin of adjacent windings mixes and, overall, a conglomerate of resin and windings is formed. To shape the outer circumference of the winding head 26, an annulus of ring segments is arranged on the rotary table 22, which ring segments are arranged so as to be radially displaceable about the centre of the coil body and together form a winding head shaping device 25. The winding head 26 can be shaped by virtue of said ring segments being moved radially onto the outer circumference of said winding head. This preferably takes place before the resin has hardened or cooled. Furthermore, during the shaping of the exterior of the winding head 26, the stripper 4 is still situated in the interior of the winding head 26. After the stripper 4 has been removed from the interior of the coil body, a spreading tool (not illustrated) is moved into the interior of the coil body. At this time, the outer circumference of the flux return ring in which the coil body is arranged is held by the segments of the holding device 8.

The resin around the windings of the coil body has still not hardened or cooled, such that the coil body can be easily shaped. In this state, the spreading tool is spread and compacts the coil body until the latter has a desired wall thickness or thickness. Here, the cavities that have formed as a result of the removal of the guide lamellae may be decreased in size or filled with windings. When the desired thickness of the winding body has been attained, the spreading tool remains in said position until the coil body has cooled or hardened and exhibits inherent strength sufficient to enable it, together with its flux return ring, to be removed from the holding device 8 without being damaged. After the hardening or cooling has taken place, the spreading tool is removed from the interior of the coil body and the segments of the holding device 8 are opened. The winding body with its flux return ring can then be removed from the internal opening of the holding device 8 and from the rotary table 22. It is optionally also possible, prior to this, for the lower winding head, which has not been formed by the drawing of the winding through the guide lamellae intermediate spaces, but which constitutes ends of the individual coils that remain outside the guide lamellae intermediate spaces, to have a desired shape imparted to them by means of suitable shaping tools before the removal of the coil body from the holding device 8. This is possible, independently of this embodiment, for all conceivable embodiments. Finally, with the holding device 8 opened and the winding head shaping device 25 opened, the coil body can be removed from the coil body production apparatus. The mode of operation of the coil body production apparatus thus comprises the simultaneous execution of multiple production steps. It is provided in particular that the following processes take place simultaneously: individual coils 5 are wound, individual coils 5 are drawn in, contacts 24 are fastened to terminal points 15 of the coil body and winding head are shaped, and/or the wall of the coil body is compacted to a predefined thickness. Between said working cycles, a transport cycle takes place in which the rotary tables 17 and 22 are rotated through 180° in order to transport the interim products from the respectively preceding station to the next station. For the transport of the holding device back from the shaping station 30 to the dra wing-in station 1, the coil body with its flux return ring is removed from the holding device 8 at the shaping station 30. The individual coils 5 may be suspended in the guide lamellae intermediate spaces manually, or preferably in automated fashion.

In addition to the above written description of the invention, reference is hereby explicitly made, for additional disclosure thereof, to the diagrammatic illustration of the invention in figures 1 to 4.

List of reference numerals

1 Drawing-in station

2 Flange

3 Guide lamellae

4 Stripper

5 Individual coils

6 Guide lamellae intermediate spaces

7 Flux return ring

8 Holding device

9 Spreading tool

10 Radial thickness of the coil body

11 Stabilizing device

12 Aperture

13 Coil body

14 Spreading forces

15 Connection points

16 Guide body

17 Rotary table

18 Axis of rotation of the rotary table 17

19 Coil-holding elements

20 Winding template

21 Cutout

22 Rotary table

23 Axis of rotation of the rotary table 22

24 Contacts

25 Winding head shaping device

26 Winding head

30 Shaping station

31 Drawing-in station

Claims

Coil body production apparatus for the production of a coil body (13) for an electric motor having a ferromagnetic flux return ring (7) with a grooveless, continuous internal cutout (21) and with an ironless air gap winding composed of multiple individual coils (5),

characterized by

- multiple guide lamellae (5) which are arranged parallel to one another and which have guide lamellae intermediate spaces (6), wherein the guide lamellae (3) can be moved into and out of the grooveless cutout (21) of the flux return ring (7),

- a stripper (4) for drawing the individual coils (5) into the guide lamellae intermediate spaces (6),

wherein the stripper (4) can be moved into the interior of the guide lamellae (3) when the guide lamellae (3) have been moved into the flux return ring (7), such that, in the process, the individual coils (5) can be picked up by the stripper (4) for the purpose of being drawn into the guide lamellae intermediate spaces (6).

Coil body production apparatus according to Claim 1, which furthermore has an introduction apparatus by means of which an individual coil (5) can be inlaid into a guide lamellae intermediate space (6).

Coil body production apparatus according to one of the preceding claims, which furthermore has a spreading tool (9) which can be moved into the coil body (13) arranged in the flux return ring (7), wherein an external diameter of the spreading tool (9) can be enlarged in order to enlarge the internal diameter of the coil body (13), whereby a predefined thickness (10) can be produced in the radial direction of the coil body (13) between the spreading tool (9) and the cutout (21) of the flux return ring (7).

Coil body production apparatus according to one of the preceding claims, which has a contacting device by means of which terminals (15) of individual coils (13) can be provided with contacts (24).

Coil body production apparatus according to one of the preceding claims, which has a holding device (8) with an internal opening, the internal diameter of which is variable, wherein the internal opening of the holding device (8) is formed preferably by multiple radially movable segments.

Coil body production apparatus according to one of the preceding claims, which comprises at least one inlaying station and one drawing-in station (1) or one drawing-in station (1) and one shaping station (30) for all three stations, wherein the inlaying station has an introduction device, the drawing-in station (1) is designed for the drawing-in of the individual coils (5) into the flux return ring (7), and the shaping station (30) is designed for shaping the coil body (13), wherein the coil body production apparatus comprises a transport device for transporting an individual coil (5) from the inlaying station to the drawing-in station (1) and/or a transport device for transporting a coil body (13) from the drawing-in station to the shaping station (30).

Coil body production apparatus according to Claim 6, which coil body production apparatus has, as transport devices, one or two work tables (17, 22), of which one work table (17) serves for the transport of individual coils (5) between the inlaying station and the drawing-in station (1), and one work table (22) serves for transporting coil bodies (13) between the drawing-in station (1) and the shaping station (30), wherein the work tables (17, 22) are in particular arranged so as to each be pivotable about an axis (18, 23).

Coil body production apparatus according to Claim 7, in which the work table (17) for the transport of individual coils (5) has two guide bodies (16) and/or the work table (22) for the transport of coil bodies (13) has, in the flux return ring (7) thereof, two holding devices (8).

Production method for the production of a coil body (13) of an electric motor with an ironless air gap winding, wherein the coil body (13) is produced from multiple individual coils (5) by means of a coil body production apparatus according to one of Claims 1 to 8,

characterized by the following steps:

- introducing respective sections of multiple individual coils (5) into multiple guide lamellae intermediate spaces (6), then

- arranging at least one section of the guide lamellae (3) in the grooveless cutout (21) of the flux return ring (7) and then - performing a relative drawing-in movement between the stripper (4) and the flux return ring (7), wherein the stripper (4) moves through the cutout (21) of the flux return ring (7) and in the interior of the guide lamellae (3), such that the individual coils (7) are drawn into the guide lamellae intermediate spaces (6) by means of the stripper (4).

Method according to Claim 9, characterized by at least one of the following additional steps:

- heating the individual coils (5) after the drawing-in of the individual coils (5),

- retracting the guide lamellae (3) out of the flux return ring (7) and the heated individual coils (5),

- retracting the stripper (4) out of the flux return ring (7),

wherein said steps are performed in particular in the stated sequence.

Method according to either of Claims 9 and 10, in which the drawing-in process and the retraction of the guide lamellae (3) takes place at a drawing-in station (1) of the coil body production apparatus, and the removal of the stripper (4) from the coil body (13) takes place at a different machining station, preferably at a shaping station (30) of the coil body production apparatus.

Method according to one of Claims 9 to 11, in which an individual coil (5) is pre-wound and inlaid, by way of one section, into a guide lamellae intermediate space (6), or an individual coil (5) is wound such that a section of the individual coil (5) comes to lie in a guide lamellae intermediate space (6), in particular on an inlaying station of the coil body production apparatus, from which the guide lamellae (5) with the individual coil (5) is preferably transported to a drawing-in station (1), wherein in particular, the guide lamellae (3) are also transported from the inlaying station to the drawing-in station (1).

Method according to one of Claims 9 to 12, in which, while the drawn-in coil body (13) is arranged in the flux return ring (7), a spreading tool (9) is introduced into the interior of the coil body (13) into a position in which said spreading tool is situated opposite an internal wall of the cutout (21) in the flux return ring (7), and the spreading tool (9) is spread there such that the radial thickness of the coil body (13) is reduced between the internal wall and the spreading tool (9),

wherein this is performed in particular in a shaping station (30) of the coil body production apparatus, and in particular, for the spreading process, the coil body (13) is transported from a drawing-in station (1) to the shaping station (30), wherein in particular, a stripper (4) in the interior of the coil body (13) and/or a flux return ring (7) around the coil body (13) are/is also transported from the drawing-in station (1) to the shaping station (30).

Method according to one of Claims 9 to 13, in which, in the coil body production apparatus, in one working cycle in the drawing-in station (1), an individual coil (5) is drawn in, and in one working cycle in the inlaying station, a further individual coil (5) is wound or inlaid into a guide lamellae intermediate space (6), and in one working cycle in the shaping station (30), a spreading process is performed, wherein at least two, preferably all three of the working cycles take place at least approximately simultaneously.

Method according to one of Claims 9 to 13, in which, in the same working cycle as that in which the spreading process is performed, terminals of the individual coils (5) are provided with contacts, and/or the coil body (13) is heated, in particular by means of a flow of current through the individual coils (5) and the respective contact thereof, in order that the individual coils are firstly softened and subsequently hardened, wherein each of the processes takes place preferably in the shaping station (30).