Method for transferring a wave winding into stator grooves
Patent Information
- Application Number
- EP2023757511
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-09-02
- Filing Date
- 2023-08-04
- Publication Date
- 2025-07-09
AI Technical Summary
Existing methods for transferring wave windings into stator slots are often space-consuming and complex, leading to potential jamming and damage to insulated wires due to radial displacement mechanisms.
The method employs two oppositely driven drive cones with mirror-symmetrical or differently inclined cone surfaces to facilitate a more efficient and space-saving radial displacement of wire webs into stator slots, allowing for a lower load on the wires and preventing damage, with the option for asynchronous movement and separate servomotors for each cone.
This approach reduces the likelihood of jamming and wire damage by enabling a smoother, more controlled transfer of wave windings into stator slots with reduced mechanical stress, while also optimizing space usage and allowing for flexible displacement profiles.
Smart Images
Figure 1.1
Abstract
Description
[0001] Method for transferring a wave winding into stator slots
[0002] According to the preamble of claim 1, the invention relates to a method for transferring a wave winding, which is received with wire webs in radially outwardly open grooves of a transfer tool / drawing mandrel, into the radial grooves of a stator, which are open to the inside, wherein the transfer tool is initially arranged centrally in the stator opening with grooves aligned with the stator grooves and by means of a drive cone an axial actuating movement of a drive element is converted into a radially outwardly directed movement of drawing-in laminations, which are arranged radially inward to the wire webs and thereby the wire webs are transferred radially outwards into the stator grooves.
[0003] Such a process is known from DE 10328 956 A1. There, the laminations are displaced outward over conical surfaces by a linearly movable drive element located centrally in the transmission tool, which can also be referred to as a drawing-in mandrel. The laminations are seated in radial guides. It has been shown that this type of radial displacement does not always ensure smooth transmission of the wave winding.
[0004] EP 3 654 502 A1 discloses a transmission method in which the retractable slats are displaced radially outward using a toggle lever. The device required for this requires a considerable amount of installation space.
[0005] EP 3 391 516 B1 describes a solution that, in addition to a drive cone, also provides means for axially pulling the wire webs into the stator slots. The mechanism for this is very complex and requires a lot of space.
[0006] The object of the present invention is to improve the process of a method of the type mentioned at the outset without the need for space-consuming devices.
[0007] According to the invention, this object is achieved by a method of the type mentioned at the outset, in which two drive cones are provided which are driven in opposite directions and each have conical surfaces acting on the lamellae, the inclinations of the conical surfaces being aligned in opposite directions. The solution according to the invention offers the advantage that a better process sequence can be achieved through a relatively simple and space-saving arrangement of a second drive cone. It has been shown that by having the two drive cones at different points on the lamellae via the oppositely inclined run-on bevels of the two drive cones, there is a lower tendency for clamping and the load on the wires can also be reduced, which is helpful in avoiding damage to already insulated wires.
[0008] In a particularly simple embodiment of the method, it is provided that the conical surfaces are formed mirror-symmetrically, although they can also be formed with different inclination profiles in order, for example, to effect a non-strictly radial displacement of the entire slats.
[0009] If, for example, a purely radial displacement of the retractable slats is to be achieved in conjunction with the previously mentioned, mirror-symmetrical drive cones, it may be desired that the two drive cones are moved synchronously towards each other and displace the slats evenly radially outwards.
[0010] Alternatively, in one embodiment of the process, it is also readily possible to drive the two drive cones with a time offset and / or different feed speeds, and to displace the laminations radially outward at one end along their length with a lead. This can enable a more gentle transfer of the wire webs into the stator slots, which are then also not pressed into the stator slots simultaneously over their entire length, but rather starting at one end with a leading winding head.
[0011] In the case of a simultaneous movement, a similar sequence can be achieved by the previously mentioned differently designed inclination profiles of the counter-rotating drive cones.
[0012] It has proven particularly useful to have the slats mounted in a floating manner. Floating means that not only a purely radial movement but also a tilting movement of the retractable slats is facilitated. The slats are then guided primarily against movement in the circumferential direction.
[0013] In a further development of the method, it is provided that before the radial displacement of the
[0014] Wire web insulation is inserted into the stator slots. This insulation, which can be in the form of folded insulating paper, for example, ensures that the winding wires cannot come into metallic contact with the stator. It can also reduce the risk of damage to the insulating layer provided on the wire webs during the insertion process.
[0015] Especially in cases where synchronous movement of the drive cones is desired, it is entirely sufficient for both drive cones to be driven by a central servomotor. Offset movement can, of course, still be achieved using suitable measures as described above.
[0016] The transmission of the actuating movement from a rotating drive shaft of a single actuator to the drive cone can, for example, be carried out in a space-saving manner by the actuator driving a threaded spindle which has two counter-rotating threads, each of which engages with a drive cone.
[0017] However, it is also perfectly possible for each drive cone to have a separate actuator, with the actuators being controlled jointly or separately. This measure can, on the one hand, promote the inclination of the retractable lamellas during their displacement into the stator slots, as already discussed above. However, providing separate motors can also be advantageous in potentially gaining space in the inner diameter, as a continuous threaded spindle is then no longer required.
[0018] In a preferred development of the method, the laminations can be displaced radially outward against the restoring force of at least one spring element acting radially inward. The restoring force assists in restoring the laminations after the wave winding has been completely transferred into the stator slots and can replace or support a mechanical positive control.
[0019] A structurally simple implementation provides for elastic bands placed axially adjacent to the stator as spring elements around the lamellae, which expand elastically radially outward as the lamellae are displaced. This solution is mechanically uncomplicated and avoids the provision of individual spring elements for each lamella. It is expedient to provide one spring element on each side of the stator. Further features, details, and advantages of the invention will become apparent from the wording of the claims and from the exemplary embodiment described below with reference to the drawings. They show:
[0020] Fig. 1 is a view of a drawing-in mandrel for use in the described method;
[0021] Fig. 2 is an oblique view of the drawing-in mandrel according to Fig. 1;
[0022] Fig. 3 an axially aligned oblique view of the retracting mandrel in the basic position;
[0023] Fig. 4 is an oblique view of the retracting mandrel in the expanded position;
[0024] Fig. 5 is an oblique view of a drawing-in mandrel equipped with a wave winding in the basic position after insertion into the inner diameter of a stator;
[0025] Fig. 6 is an oblique view similar to Fig. 5 in an intermediate position;
[0026] Fig. 7 is a detailed oblique view similar to Fig. 6 in the expanded final position of the retracting mandrel.
[0027] Fig. 1 shows a side view of a drawing-in mandrel 10 comprising a transfer tool having radially outwardly open grooves 12 formed by spaced ribs 14. The ribs 14 have interruptions in their axial direction, which can serve the engagement of handling devices when loading the grooves 12 with wire webs 16 of a wave winding 18 (see Figs. 5 to 7) from a linear magazine, which is not the subject of this application.
[0028] The star-shaped ribs 14 are connected to a core in a non-visible area, with axially extending pull-in laminations 20 arranged between this core and the visible slots 12, which are guided in a floating manner in the radial direction. The number of pull-in laminations 20 corresponds to the number of slots 12, which in turn correspond to the number of slots 22 of a stator 24 that is to be equipped with the wave winding 18 (see Figs. 5 to 7).
[0029] The retractable slats 20 are wrapped on both sides of the grooves 12 / ribs 14 with elastic bands 26, which tend to retract the retractable slats 20 into the basic position shown in Fig. 1, 3 and 5.
[0030] In Fig. 2 it can be clearly seen that the pull-in lamellae 20 are wider in the circumferential direction outside the grooves 12, so that their movement in the grooves 12 radially inwards is limited by the fact that these thickened regions 28 of adjacent pull-in lamellae 20 abut one another.
[0031] The retracting mandrel 10 is limited in the axial direction by two spindle bearings 30, 32, in which a threaded spindle 34 (see Fig. 7) is rotatably mounted. Furthermore, two drive cones 36, 38 are arranged on the spindle bearings 30, 32 for axial movement by means of axial guides 40.
[0032] The two drive cones 36, 38 have conical contact surfaces 42, 44, which are largely hidden in the illustrations and act on the retractable slats 20. The conical contact surfaces 42, 44 of the two drive cones 36, 38 are mirror-symmetrical in the illustrated embodiment, but embodiments are also possible in which the inclination profiles of the conical surfaces 42, 44 are designed differently, even apart from the mirror-inverted arrangement.
[0033] The threaded spindle 34 engages with corresponding internal threads (not visible) of the two drive cones 36, 38, but their respective thread sections in these areas are designed with opposing pitches, so that the drive cones 36, 38 always move in opposite axial directions when the threaded spindle 34 rotates, so that the drive cone 36 on one side of the retraction mandrel 10 then displaces the retraction slats 20 radially outwards, even if the other drive cone 38 on the opposite side of the retraction mandrel also radially lifts the retraction slats 20.
[0034] This movement can, but does not have to, be synchronous, ie it is possible that the radial lifting of the retractable lamellas 20 takes place on one side with advance, so that the wire webs are not transferred simultaneously over their entire length into the stator slots.
[0035] During the transmission process, the drive cones 36, 38 are displaced axially away from the spindle bearings 30, 32 and, in the expanded end position (see Fig. 7), are located completely within the surrounding pull-in slats 20. Fig. 7 also shows run-on bevels 46 on the inner sides of the pull-in slats 20, which interact with the conical contact surfaces 42, 44 of the drive cones 36, 38.
[0036] Figs. 3 and 4 illustrate the difference in the radial positions of the retractable lamellae 20 between a radially retracted basic position (Fig. 3) and an expanded position (Fig. 4). Due to the radially outward star-shaped movement, the distances between the retractable lamellae 20 also increase in the circumferential direction, and the elastic band 26 is subjected to greater tension due to the correspondingly expanding outer diameter of the lamella pack.
[0037] Figs. 5 to 7 show the process of inserting the wave winding 18 into the stator slots 22. First, the wave winding 18 was transferred in four layers, each with two, i.e., a total of eight, superimposed wire webs 16, into the slots 12 of the insertion mandrel 10. The insertion mandrel, together with the wave winding, was then inserted into the inner diameter of the stator 24 so that the wire webs 16 in the slots 12 of the insertion mandrel 10 are aligned with the stator slots 22.
[0038] In this initial position, the drive cone 38 is in its retracted position, in which the conical surfaces 42, 44 are partially axially outside the retractable slats 20.
[0039] The insertion process is performed by rotating the threaded spindle 34, which can be driven by a drive motor. The two drive cones 36, 38 now move toward each other and push the insertion laminations 20 radially outward. The intermediate position shown in Fig. 6, in which the wire webs 16 of the wave winding are already partially transferred into the stator slots, is reached, leading to the final position shown in Fig. 7, in which the wave winding has been completely transferred into the stator slots 22.
[0040] After the transfer is complete, the threaded spindle 34 is rotated in the opposite direction, causing the two drive cones 36, 38 to move away from each other and allowing the retracting blades 20 to return to their rest position under the action of the return spring 26. The finished stator 24 can now be removed from the retracting mandrel 10 and further processed.
[0041] In Fig. 6, the C-shaped insulations 48 made of insulating paper inserted into the stator slots 22 can also be seen, which were inserted into the stator slots 22 before the drawing mandrel was inserted into the interior of the stator 24.
[0042] The invention is not limited to one of the embodiments described above, but can be modified in many ways.
[0043] All features and advantages arising from the claims and the description, including design details, spatial arrangements and method steps, can be essential to the invention both individually and in a wide variety of combinations.
[0044] Reference symbol list
[0045] 10 retracting mandrel
[0046] 12 grooves
[0047] 14 ribs
[0048] 16 wire bridges
[0049] 18 wave winding
[0050] 20 retractable slats
[0051] 22 stator slots
[0052] 24 Stator
[0053] 26 elastic bands
[0054] 28 thickened areas (of the lamellae)
[0055] 30, 32 spindle bearings
[0056] 34 threaded spindle
[0057] 36, 38 drive cones
[0058] 40 axial guides
[0059] 42, 44 conical contact surfaces
[0060] 46 run-on bevels
[0061] 48 insulations
Claims
Patent claims 1. A method for transferring a wave winding (18), which is received with wire webs (16) in radially outwardly open grooves (12) of a transfer tool / drawing mandrel (10), into the radial grooves (22) of a stator (24), which are open inwards, wherein the transfer tool (10) is initially arranged centrally in the stator opening with the grooves (12) aligned with the stator grooves (22) and by means of a drive cone (36, 38) an axial adjusting movement is converted into a radially outwardly directed movement of drawing-in laminations (20) which are arranged radially inward to the wire webs (26) and thereby the wire webs (26) are transferred radially outwards into the stator grooves (22), characterized in that two drive cones (36, 38) are provided, which are driven in opposite directions and each have conical surfaces (42, 44) on the drawing-in laminations (20), wherein the inclinations of the conical surfaces (42, 44) are oppositely oriented.
2. Method according to claim 1, characterized in that the conical surfaces (42, 44) are mirror-symmetrical or have different inclination profiles.
3. Method according to claim 1 or 2, characterized in that the two drive cones (36, 38) are moved synchronously towards each other and displace the retraction slats (20) uniformly radially outwards.
4. Method according to claim 1 or 2, characterized in that the two drive cones (36, 38) are driven with a time offset and / or different feed speed and the drawing-in slats (20) are displaced radially outwards at one end with advance, seen over their length.
5. Method according to one of the preceding claims, characterized in that the retractable slats (20) are mounted in a floating manner.
6. Method according to one of the preceding claims, characterized in that insulation (48) is inserted into the stator slots (22) before the wire webs (16) are radially displaced.
7. Method according to one of the preceding claims, characterized in that both drive cones (36, 38) are driven by a central servo motor.
8. Method according to claim 7, characterized in that the servo motor drives a threaded spindle (34) which has two opposing threads, each of which engages with a drive cone (36, 38).
9. Method according to one of claims 1 to 6, characterized in that each drive cone has a separate servomotor, which are controlled jointly or separately from one another.
10. Method according to one of the preceding claims, characterized in that the retractable slats (20) are displaced radially outwards against the restoring force of at least one spring element (26) acting radially inwards.
11. Method according to claim 10, characterized in that elastic bands lying axially next to the stator (24) are placed around the retraction lamellae (20) as spring elements (26), which elastic bands expand elastically radially outwards during the displacement of the retraction lamellae (20).