Method for transferring a wave winding into a stator slot

Abstract

The invention relates to a method for transferring a wave winding (18) into an inwardly open radial groove (22) of a stator (24), the wire projection (16) of which is accommodated in a radially outwardly open groove (12) of a transfer tool / pull-in mandrel (10), in which first the transfer tool (10) is arranged centrally in the stator opening and the groove (12) is aligned with the stator groove (22), and then the wire projection (16) of the wave winding (18) is accommodated in the radially outwardly open groove (12) of the transfer tool / pull-in mandrel (10). And by means of the drive cones (36, 38), the axial actuation movement is converted into a radially outwardly directed movement of the pull-in fins (20) arranged radially inward with respect to the wire projections (26) and thereby transfers the wire projections (26) radially outwardly into the stator grooves (22). In order to improve the method, according to the invention two drive cones (36, 38) are provided, which are driven in opposite directions, and the respective conical surfaces (42, 44) act on the pull-in fins (20), the gradients of which are oriented oppositely.

Description

Technical Field

[0001] According to the preamble of claim 1, the invention relates to a method for transferring a wave winding into an inwardly open radial groove of a stator, the wire projection of the wave winding being accommodated in a radially outwardly open groove of a transfer tool / pull-in mandrel, wherein the transfer tool is first arranged centrally in the stator opening with the groove aligned with the stator groove, and with the aid of a drive cone an axial actuation movement is converted into a radially outwardly directed movement of a pull-in fin arranged radially on the inside with respect to the wire projection, and the wire projection is thereby transferred radially outwardly into the stator groove. Background Art

[0002] Such a method is known from DE 103 28 956 A1. Here, a linearly movable drive element arranged centrally in a transfer tool is used to displace the fins outwards on a conical surface, which drive element can also be referred to as a pull-in mandrel. The fins are located in radial guides. It has been shown that this type of radial displacement does not always enable a smooth transfer of the wave winding.

[0003] A transfer method is known from EP 3 654 502 A1, in which the pull-in fins are displaced radially outwards by means of a toggle link. The device required for this requires a large installation space.

[0004] EP 3 391 516 B1 describes a solution in which, in addition to the drive cone, a device is provided for axially pulling the wire projection into the stator groove. The mechanism for this device is very complex and requires a large installation space. Summary of the invention

[0005] The object of the invention is to improve the procedure of a method of the type mentioned at the outset without requiring space-consuming devices.

[0006] 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 act on the fins with respective cone surfaces whose inclinations are oriented in opposite directions.

[0007] The solution according to the invention offers the advantage that a better process sequence can be achieved by means of a relatively simple and space-saving arrangement of the second drive cone. It has been shown that two drive cones having oppositely inclined start bevels at different points on the fin means that there is less tendency to clamp and the load on the wire can also be lower, which helps to avoid damage to the already insulated wire.

[0008] In a particularly simple embodiment of the method, it is provided that the conical surfaces are mirror-symmetrical, but they can also be designed with different inclined contours in order, for example, to achieve a non-strict radial displacement of all fins.

[0009] For example, in case of achieving a purely radial displacement of the pull-in fins in combination with the previously mentioned mirror-symmetrical drive cones, it may be desired that the two drive cones move synchronously towards each other and the fins are displaced radially outwards in unison.

[0010] Alternatively, in one embodiment of the method, the two drive cones can also be driven in a time-shifted manner and / or at different feed speeds and, viewed over their length, the fins are displaced radially outwards at a front end. This can allow a more gentle transfer of the wire projection into the stator groove, which is then also not pressed into the stator groove simultaneously over its entire length, but rather starting from one end with the front winding head.

[0011] In the case of simultaneous movement, a similar sequence can be achieved by the previously mentioned different inclination profiles of the opposing drive cones.

[0012] It has proven to be particularly useful to mount the fins in a floating manner. "Floating" means that both pure radial movement and tilting movement of the pull-in fins are facilitated. The guidance of the fins is then mainly carried out for movement in the circumferential direction.

[0013] In a further development of the method, it is provided that insulating elements are inserted into the stator grooves before the wire projections are radially displaced. These insulating elements ensure that the wires of the winding cannot come into metallic contact with the stator, and they can be in the form of folded insulating paper, for example. These insulating elements can also reduce the risk of damage to the insulating layer provided on the wire projections during the pulling-in process.

[0014] Particularly in the case where synchronous transmission of the drive cone is required, two drive cones are fully sufficient to be driven by the central drive. Of course, the offset movement can still be achieved by taking the appropriate measures described above.

[0015] The transmission of the actuating movement from a rotating drive shaft of a single actuator to a drive cone can be realized in a space-saving manner, for example, wherein the actuator drives a threaded spindle having two opposite threads, which each engage with a drive cone.

[0016] However, each drive cone can also have a separate actuator, wherein the actuators are controlled jointly or individually. On the one hand, this measure can facilitate the tilting of the pull-in fin during displacement into the stator groove, which has already been explained above.

[0017] However, since a continuously threaded spindle is no longer required, it may also be advantageous to provide a separate motor in order to achieve a potential gain in installation space in the inner diameter.

[0018] In a preferred further development of the method, it can be provided that the fins are displaced radially outwards against the restoring force of at least one spring element acting radially inwards. After the wave winding has been completely transferred into the stator groove, the restoring force helps to reset the lamination and can replace or support the mechanical override.

[0019] Here, a structurally simple implementation is to place elastic bands placed axially adjacent to the stator around the fins as spring elements, which elastically expand radially outwards during displacement of the fins. This solution is mechanically uncomplicated and avoids providing a separate spring element for each fin. It is proposed to provide a spring element on each side of the stator. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Further features, details and advantages of the invention emerge from the wording of the claims and from the exemplary embodiments described below with reference to the accompanying drawings. In the drawings:

[0021] Figure 1 shows a view of a pull-in mandrel for use in the described method;

[0022] Figure 2 Shown according to Figure 1 An oblique view of the pull-in mandrel;

[0023] Figure 3 an oblique view showing the axial alignment of the pull-in mandrel in the basic position;

[0024] Figure 4 An oblique view of the pull-in mandrel is shown in an extended position;

[0025] Figure 5 An oblique view showing the pull-in mandrel in basic position fitted with the wave winding after insertion into the inner diameter of the stator;

[0026] Figure 6 Shown with Figure 5 Similar oblique view in intermediate position;

[0027] Figure 7 Shown with Figure 6 Similar oblique detail view of the pulled-in mandrel in the extended final position. DETAILED DESCRIPTION

[0028] exist Figure 1, a side view of a pull-in mandrel 10 is shown, which includes a transfer tool having a radially outwardly open groove 12 formed by spaced ribs 14. The ribs 14 have interruptions in their axial direction, and when the groove 12 is connected to the wire protrusion 16 of the wave winding 18 from the linear magazine (see Figures 5 to 7 ) when assembled together, this may facilitate the engagement of the processing device, which is not the subject of the present application.

[0029] The star-shaped ribs 14 are connected to the core in the non-visible area, wherein between the core and the visible grooves 12 therein are arranged axially extending pull-in fins 20 which are guided in a floating manner in the radial direction. The number of pull-in fins 20 corresponds to the number of grooves 12, which in turn corresponds to the number of grooves 22 of the stator 24 which are to be equipped with the wave windings 18 (see Figures 5 to 7 ) corresponds to the number of ).

[0030] The pull-in fin 20 is surrounded on both sides of the groove 12 / rib 14 by an elastic band 26 which tends to retract the pull-in fin 20 into the groove 12 / rib 14. Figure 1 , Figure 3 and Figure 5 in the basic position shown in .

[0031] exist Figure 2 In FIG. 1 , it can be clearly seen that the pull-in fins 20 outside the groove 12 are wider in the circumferential direction, so that the movement of the pull-in fins in the groove 12 is limited radially inwardly due to the fact that the thickened areas 28 of adjacent pull-in fins 20 abut against each other.

[0032] The pull-in spindle 10 is limited in the axial direction by two spindle bearings 30, 32, a threaded spindle 34 (see Figure 7 ) is rotatably mounted in the two spindle bearings. In addition, two drive cones 36, 38 are arranged on the spindle bearings 30, 32 so as to be axially movable by means of an axial guide 40.

[0033] The two drive cones 36, 38 have conical contact surfaces 42, 44 which are largely concealed in the illustration and act on the pull-in fin 20. In the exemplary embodiment shown, the conical contact surfaces 42, 44 of the two drive cones 36, 38 are mirror-symmetrical, but in addition to the mirror-inverted arrangement, embodiments are also possible in which the inclined profiles of the conical surfaces 42, 44 are designed differently.

[0034] The threaded spindle 34 engages with corresponding internal threads (not visible) of two drive cones 36, 38, but the respective thread sections of the threaded spindle and the two drive cones in these areas are designed to have opposite pitches so that when the threaded spindle 34 rotates, the drive cones 36, 38 always move in opposite axial directions, so that the drive cone 36 located on one side of the pull-in spindle 10 subsequently displaces the pull-in fin 20 radially outward while the other drive cone 38 located on the opposite side of the pull-in spindle also radially lifts the pull-in fin 20.

[0035] This movement can be synchronous, but does not necessarily have to be, that is, the radial lifting of the pull-in fin 20 can be performed on one front side, so that the wire projection is not transferred into the stator groove simultaneously over its entire length.

[0036] During the transfer process, the drive cones 36, 38 are axially displaced away from the spindle bearings 30, 32 and in the extended end position (see Figure 7 ) is completely located within the surrounding pull-in fin 20. Figure 7 In FIG. 2 , activation ramps 46 can also be seen on the inner side of the pull-in fin 20 , which interact with the conical contact surfaces 42 , 44 of the drive cones 36 , 38 .

[0037] Figure 3 and Figure 4 The radial position of the pull-in fin 20 is shown in the basic radially pulled-in position ( Figure 3 ) and the extended position ( Figure 4 Due to the radially outward star-shaped movement, the distance between the pull-in fins 20 also increases in the circumferential direction and the elastic band 26 is tightened more tightly by the correspondingly expanded outer diameter of the fin package.

[0038] exist Figures 5 to 7 , the process of pulling the wave winding 18 into the stator groove 22 is shown. First, the wave winding 18 is transferred into the groove 12 of the pull-in mandrel 10 in four layers, each layer having two superimposed wire protrusions 16, i.e., there are a total of eight superimposed wire protrusions. Then, the pull-in mandrel with the wave winding is inserted into the inner diameter of the stator 24 so that the wire protrusions 16 in the groove 12 of the pull-in mandrel 10 are aligned with the stator groove 22.

[0039] In this initial position, the drive cone 38 is in its retracted position in which the conical surfaces 42 , 44 are located partially axially outside the retracted fin 20 .

[0040] The pull-in process is performed by turning the threaded spindle 34, which can be done by a drive motor. Now, the two drive cones 36, 38 move toward each other and push the pull-in fin 20 radially outward. Figure 6 The intermediate position shown is reached Figure 7 The final positions shown are, in the intermediate position, the wire projections 16 of the wave winding have been partially transferred into the stator grooves, and in the final position, the wave winding has been completely transferred into the stator grooves 22 .

[0041] After the transfer has occurred, 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 pull-in fin 20 to move back to the rest position under the action of the return spring 26. The finished stator 24 can now be removed from the pull-in mandrel 10 and further processed.

[0042] exist Figure 6 In FIG. 2 , one can also see the C-shaped insulating pieces 48 made of insulating paper which are inserted into the stator grooves 22 , which are inserted into the stator grooves 22 before the pull-in mandrel is inserted into the interior of the stator 24 .

[0043] The present invention is not limited to one of the above-described embodiments but may be modified in various ways.

[0044] All features and advantages arising from the claims and the description, including design details, spatial arrangements and method steps, may be essential to the invention both individually and in any combination.

[0045] Reference numerals list

[0046] 10 Pull-in mandrel

[0047] 12 Grooves

[0048] 14 Ribs

[0049] 16 Wire protrusion

[0050] 18 Wave winding

[0051] 20 Pull-in fins

[0052] 22 Stator slots

[0053] 24 Stator

[0054] 26 Elastic Band

[0055] 28 Thickened area (of fin)

[0056] 30, 32 spindle bearings

[0057] 34 threaded spindle

[0058] 36, 38 drive cone

[0059] 40 Axial guide

[0060] 42, 44 Conical contact surface

[0061] 46 Start ramp

[0062] 48 Insulation.

Claims

1. A method for transferring a wave winding (18) into an inwardly open radial groove (22) of a stator (24), wherein the wire projection (16) of the wave winding is received in a radially outwardly open groove (12) of a transfer tool / pull-in mandrel (10), wherein: First, the transfer tool (10) is arranged centrally in the stator opening, and the groove (12) is aligned with the stator groove (22), and the axial actuation movement is converted into a radially outwardly directed movement of the pull-in fin (20) arranged radially inside relative to the wire protrusion (26) by means of a drive cone (36, 38), thereby transferring the wire protrusion (26) radially outward into the stator groove (22), characterized in that two drive cones (36, 38) are provided, the two drive cones are driven in opposite directions, and the respective conical surfaces (42, 44) act on the pull-in fin (20), the inclinations of the conical surfaces (42, 44) being oriented in opposite directions.

2. The method according to claim 1, characterized in that The tapered surfaces (42, 44) are mirror-symmetrical or have different inclined profiles.

3. The method according to claim 1 or 2, characterized in that: The two drive cones (36, 38) move synchronously toward each other and displace the pull-in fins (20) radially outward in unison.

4. The method according to claim 1 or 2, characterized in that: The two drive cones (36, 38) are driven in a time-shifted manner and / or at different feed speeds and, viewed over the length of the two drive cones, the pull-in fin (20) is displaced radially outward at a front end.

5. The method according to any one of the preceding claims, characterized in that The pull-in fin (20) is installed in a floating manner.

6. The method according to any one of the preceding claims, characterized in that Before the wire projections (16) are radially displaced, an insulator (48) is inserted into the stator grooves (22).

7. The method according to any one of the preceding claims, characterized in that The two drive cones (36, 38) are driven by a central actuator.

8. The method according to claim 7, characterized in that The actuator drives a threaded spindle (34) having two opposed threads that each engage a drive cone (36, 38).

9. The method according to any one of claims 1 to 6, characterized in that Each drive cone has a separate actuator which can be controlled together or separately from one another.

10. The method according to any one of the preceding claims, characterized in that The pull-in fin (20) is displaced radially outward against the restoring force of at least one spring element (26) acting radially inward.

11. The method according to claim 10, characterized in that An elastic band located axially adjacent to the stator (24) is arranged around the pull-in fin (20) as a spring element (26), which elastically expands radially outward during displacement of the pull-in fin (20).

Images