Method for installing a stator with a wave winding
Patent Information
- Application Number
- EP2023798105
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-11-08
- Filing Date
- 2023-10-19
- Publication Date
- 2025-09-17
AI Technical Summary
Existing methods for assembling stators with wave windings face challenges such as damage to insulation, electrical losses, and inefficient magnetic field guidance due to complex processes and geometric limitations, particularly in internal rotors and radially grooved stators of radial flux machines.
A method where only part of the toothed segments are initially arranged in a receptacle, gradually advanced radially outward as the wave winding is formed, allowing for more space and preventing collisions, with additional segments inserted in subsequent revolutions, and using adjustable guides and rollers to maintain the winding at its final radius, eliminating the need for radial inward displacement and allowing for flexible adjustment of tooth geometry.
This method simplifies the assembly process, prevents winding head expansion, and allows for a more efficient stator design with improved slot-tooth geometry, enabling better magnetic field guidance and reduced electrical losses.
Smart Images
Figure 1.1
Abstract
Description
[0001] Method for assembling a stator with a wave winding
[0002] According to the preamble of claim 1, the invention relates to a method for assembling a stator with a wave winding which is arranged in slots of the stator and has winding heads projecting axially beyond a stator body, wherein toothed segments held in a receptacle are provided between the slots, which are fed radially outwards according to the height of the wire layers during the linear feeding of the mat-like wave winding and corresponding rotation of the receptacle and form the slots for wires of the wave winding between them.
[0003] Known processes involve first transferring the wave winding mats to a tool with radially outwardly open slots. Then, in a single transfer step, the tool is inserted centrally into the stator and pushed radially outward into the inwardly open slots of the one-piece stator. In addition to the complex process, which can result in damage to the sensitive insulation of the wave winding wires, open-ended slots have the disadvantage of increasing electrical losses and compromising magnetic field guidance.
[0004] Alternatively, it is already known, for example from EP 3 886 303 A1, to roll the winding mats inward into radial grooves open on the outside of the stator circumference. However, the radial displacement of the wires leads to undesirable elevations in the winding heads due to the decreasing circumference of the winding layer.
[0005] An alternative approach based on laminated core segmentation is described in DE102011000172. The assembly problem is solved there by installing segmented double teeth into a winding by radially shifting them from the outside to the inside. While this does not increase the winding head height, it does not allow for the installation of a magnetically preferred laminated core geometry with pronounced pole pieces or tooth heads. Similar design features of the groove and tooth geometry apply as in the previously described application.
[0006] EP 3 731 379 B1 already describes a solution for rolling each winding layer to its final radius. For this purpose, a segmented stator is used in which all tooth segments are initially displaced radially inwards into what will later be the central recess of the stator when the first winding layer is wound into a holder, and then radially outwards in the subsequent layers in accordance with the heights of the winding layers. Due to the narrow space in the middle, the tooth segments in the stator are relatively widely spaced, so that the actual slots are only subsequently formed by inserting additional stator segments radially from the outside to the inside between the tooth segments. The stator only receives its final structure when these stator segments are inserted.The number of grooves and their dimensions are limited by the described process, which in turn can have disadvantages in terms of efficiency.
[0007] The object of the present invention is to provide a method which enables an improved production of a stator and is suitable, for example, for internal rotors or radially slotted stators of radial flux machines.
[0008] According to the invention, the object is achieved by a method of the type mentioned at the outset, in which during a first rotation of the holder only some of the toothed segments are arranged in the holder and are advanced radially outwards in accordance with the height of the inner wire layers and then during at least one subsequent rotation further toothed segments are inserted into the holder from the inside and advanced radially outwards, so that after the last rotation of the holder and the winding of the entire wave winding all toothed segments have been inserted and moved into their radial end position or the last toothed segments are finally inserted and moved radially outwards.
[0009] Because the tooth segments are not all arranged in the interior of the future stator at the beginning of the process, there is more space available to gradually introduce the tooth segments into the process at closer circumferential spacing. Since the tooth segments are still shifted relatively far radially inwards in the first winding layer, not all of the tooth segments are initially introduced during the first revolution to prevent them from colliding at their radially inner end. With further radial displacement outwards, the available space then expands so that the additional tooth segments are fed into the holder during the second revolution. If necessary, the supply of additional tooth segments can also take place over the course of further revolutions of the holder. The tooth segments added later can, but do not have to, be shifted immediately to the radial level of the winding layer currently being wound.The tooth segments that are added later find their way between the wire webs of the winding mat that connect the winding heads and bring them into their desired position.
[0010] Preferably, all toothed segments are moved axially into the stator interior before being inserted radially outward into the receptacle and then gradually displaced radially outward. When mounted on internally slotted stators for radial flux machines, no radial inward displacement occurs during the entire process.
[0011] The solution according to the invention offers the further advantage that no additional steps are required in which further segments must be displaced radially from the outside to the inside, thus significantly simplifying the process. With a new layer, the level of the supplied wave winding can be adjusted. This can also be achieved in a conventional manner by depositing the winding mat in a correspondingly stepped linear magazine that feeds the winding mat.
[0012] Since the winding mat is always fed into its position in the stator at its final radius, there is no risk of the winding heads increasing in height during the process.
[0013] A further advantage of radially mounting the teeth into the partially or fully fed wave winding mat is that there is no geometric restriction regarding the number of layers of the winding or the corresponding tooth length in the radial direction, with the exception of the stator inner diameter.
[0014] In a preferred development of the method, it is provided that before the first rotation of the holder, only every second tooth segment is inserted into the holder or, in a discontinuous sequence, only every second or third tooth segment is inserted into the holder.
[0015] In order to facilitate the insertion, in particular of the tooth segments added later, a particularly preferred development of the method provides for rounded or bevelled joining aids to be mounted on the radially outer tips of the tooth segments before the tooth segments are inserted into the receptacle.
[0016] The joining aids can also be designed to slightly overlap the axial ends or to enclose the tooth contour. They can also be removed again after assembly if necessary. In an advantageous development of the method, the receptacle is formed from two half-shells with axial projections. Radial guides for the tooth segments are formed between the facing projections by moving the two half-shells axially toward each other.
[0017] This solution offers the advantage that the half-shells can be easily inserted into the stator interior to form the mount. They can be removed just as easily after the process is complete.
[0018] The half shells can have a larger diameter outside the stator interior than this, since they can be inserted axially into the interior from opposite sides with their areas guiding the tooth segments.
[0019] If other shapes for the tooth flanks are desired, the process can be configured such that the distances between the axial projections are designed differently in the region of their axial ends, so that the widths of the guide grooves can be adjusted by adjusting the axial position of the half-shells relative to each other, allowing, for example, tooth segments with a conical longitudinal section to be used. The flexible adaptation to different tooth widths can be used, for example, for the assembly of different product geometries on a single fixture.
[0020] A particularly useful and easily implemented measure for further developing the method provides for an assembly device with an adjustable linkage in the holder, by means of which the toothed segments are displaced radially outwards. This linkage can be designed, for example, in the form of a rotary cam which is rotated further into a position with a larger effective radius after each rotation of the holder, so that the passing toothed segments are also pushed radially further outwards in the guides of the holder. The toothed segments added later can be displaced by a correspondingly greater distance to the same radial level as the toothed segments added earlier by appropriately designing the contact surface, so that all toothed segments are arranged at the level of the mat layer currently being wound.While it is possible to initially feed all the toothed segments used during one rotation of the holder and insert them into the holder's guides before the start of this rotation, it is preferably provided that the toothed segments are successively fed into the holder from a magazine. This can be done, for example, by means of a gripper robot, which removes the toothed segments from a magazine outside the stator interior and inserts them radially outward from the interior into the designated guide.
[0021] In a particularly preferred embodiment of the invention, several rollers are used for wire guidance, by means of which the wave winding is deformed to the desired radius of the current winding layer of the stator. These rollers ensure that, after the wave winding is removed from its linear magazine, the winding mat follows the radius of the stator winding without blocking the necessary mounting space for the teeth.
[0022] A suitable embodiment of the device can provide that the rollers, which can also be spring-mounted, are adjusted to a certain distance from the axis of rotation of the holder according to the respective winding position.
[0023] A further measure prior to the actual process may involve coating and insulating tooth segments using a primary forming process.
[0024] In a preferred development of the method, it is provided that after the winding of the wave winding between the tooth segments, a stator yoke is pressed axially, which gives the stator its final shape and stabilizes it mechanically.
[0025] It is possible that the mount will not become part of the final stator, but it may be. It can be removed, in particular, if a stator yoke completes the stator after the wave winding is wound between the toothed segments, e.g., by axial pressing.
[0026] A multi-part stator produced by the method, which has a plurality of individual teeth with parallel tooth flanks, between which a winding with winding heads is held, and a stator yoke, has the special property that the spacing of the teeth and their length are selected such that in the event of an imaginary radial displacement of the teeth, a collision of adjacent teeth would occur before the teeth would come out of the slots.
[0027] This special geometric property enables the design of a particularly efficient stator, which is only possible with the previously presented inventive method. Such a segmented stator has a better ratio of number of slots to number of teeth, stator inner diameter, and / or slot depth for a wave-wound stator with parallel tooth flanks. The size of the winding overhangs, which do not contribute to performance, can also be kept smaller than is possible with the prior art.
[0028] 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:
[0029] Fig. 1 is a schematic side view of the beginning of the process;
[0030] Fig. 2 is a developed partial view of two receptacles forming a receptacle for tooth segments;
[0031] Fig. 3 is a side view similar to Fig. 1 after the start of the assembly process;
[0032] Fig. 4 a developed partial view of a holder with inclined guide flanks.
[0033] To illustrate an assembly process, Fig. 1 schematically shows a state at the beginning of the transfer of a wave winding 10, present as an elongated mat, into a stator 12 to be assembled: toothed segments 14, which form the future stator slots of the stator between them. At this early stage of the process, in which the first wire webs 16 have just reached the first toothed segment 14 and the wave winding still has a purely linear, mat-like extension, only a few toothed segments 14 have been inserted into a circular ring-shaped receptacle 16 with radial guides 18 (see Fig. 2), with rounded joining aids 20 being attached to the radially outer tips of the toothed segments.In this initial phase, the toothed segments 14 do not occupy directly consecutive radial guides 18, but only every second or third guide, so that sufficient space remains in the central space so that the consecutive toothed segments 14 do not collide with one another and there is also space for a robot gripper 22, which removes the toothed segments 14 from a magazine located outside the central space and inserts them into the radial guide provided. At the radially inner ends, the toothed segments 14 have lateral projections 24, which later partially close the stator slots radially on the inside and prevent the conductor wires from escaping from the slots.
[0034] Of the winding mats, only a few double-layer wire webs 26 are shown, which are intended to lie in the later axial slots of the stator. The schematic representation shows only approximately every fourth wire web, whereby—as already mentioned—not all toothed segments 14 are inserted into the receptacle during the first layer winding by rotating the receptacle. In the illustrated embodiment, a toothed segment is inserted into every second radial guide 18; the remaining radial guides 18 are then inserted during the second rotation of the receptacle 16, when the toothed segments 14 from the first rotation have already been displaced radially outwards somewhat, so that their tips lie between the wire webs 26.
[0035] The radial displacement of the toothed segments 14 is achieved by means of a mounting device 28, which is essentially an adjustable link in the form of a rotatable cam 30. In Figs. 1 and 3, this cam is shown in a first position, into which it radially pushes the passing toothed segments 14 outward into the first radial position with a run-on bevel 32. This displacement occurs in a region in which the winding mat touches the receptacle 16, so that the trailing, next toothed segment 14 is still radially retracted and cannot collide with the wire webs 26 of the winding mat 10.
[0036] During a subsequent rotation, the cam 30 is rotated clockwise, so that the run-on bevel 32 extends radially further outward. Nevertheless, the beginning of the run-on bevel 32 is still located in the radially inner region shown in Fig. 1, so that the subsequently inserted tooth segments 14 can be displaced radially outward by a correspondingly greater total distance.
[0037] Fig. 2 shows a developed plan view of part of the receptacle 16 with the radial guides 18. The receptacle 18 consists of two annular half-shells 34, 36. These have axial projections 38, 40 facing one another, which are aligned with the projections 38, 40 of the other half-shell 34, 36, so that the radial guides are formed between them.
[0038] The half-shells 34, 36 can be removed by axially pulling them apart after assembly of the stator, unless they are designed as a component of the stator. In order to be able to wind the supplied winding mat 10 around the intended circumference, several forming rollers 42 are provided, which are arranged in sequence and describe a radius that corresponds to the outer diameter of the current winding layer of the winding mat 10. The rollers 42 are generally arranged directly next to the toothed segments 14 and act on the winding heads of the winding mat. The positions of the rollers 42 are adjustable and can thus be adapted to the radius of the layer of the winding mat 10 currently being wound. The rollers 42 can be spring-mounted.
[0039] Starting from Fig. 1, Fig. 3 shows a somewhat advanced stage of the assembly process, wherein the first toothed segments 14 with intermediate wire webs 26 have reached the area of the forming rollers 42. As already mentioned, not all of the wire webs 26 are shown and only some of the toothed segments 14 have been mounted, i.e. there are still free spaces between the toothed segments which are only filled in the second revolution, or possibly only in later revolutions if more than two layers of the winding mat are wound up or if there is not enough space initially. It is also possible to complete the winding process first and then add the missing tooth segments at the end, for example if the space inside is particularly limited.
[0040] It is also clearly visible in Fig. 3 that the tooth segments 14 project radially beyond the forming rollers.
[0041] While the devices shown in Fig. 1, 2 and 3 are suitable for forming stator slots that widen conically, the formation of stator slots with parallel slot walls can also be achieved by means of tooth segments 14 that are conically formed in longitudinal section. Since the tooth segments can then no longer be guided in guide slots with a constant cross-section, Fig. 4 shows an embodiment of a receptacle 116 in which the half-shells 134, 136 are designed such that the axial projections 138, 140 have a greater distance between them in the region of their ends, which tapers conically towards the base bodies of the half-shells 134, 136. By means of a greater axial distance between the half-shells 134, 136 at the beginning of the process, a radial guide 138 for larger cross-sections of the conical tooth segments 14 can be achieved.By axially adjusting the two half-shells, the effective width of the radial guide 118 can then be adjusted to the radially inwardly decreasing cross-section of the toothed segments 14. After the winding mat 10 has been completely wound and all toothed segments 14 have been inserted, a stator yoke can be inserted axially to complete the stator, providing mechanical stability to the stator. The half-shells 34, 36 of the holder 16 can be removed if necessary and used when assembling additional stators.
[0042] The invention is not limited to one of the above-described embodiments, but can be modified in a variety of ways. All features and advantages arising from the claims and the description, including structural details, spatial arrangements, and method steps, can be essential to the invention both individually and in a wide variety of combinations.
[0043] Reference symbol list
[0044] 10 wave winding / winding mat
[0045] 12 Stator
[0046] 14 tooth segments
[0047] 16 recording
[0048] 18 radial guides
[0049] 20 joining aids
[0050] 22 robot grippers
[0051] 24 lateral projections
[0052] 26 wire bridges
[0053] 28 Mounting device
[0054] 30 rotating cam
[0055] 32 run-on slope
[0056] 34, 36 half shells
[0057] 38, 40 axial projections
[0058] 42 forming rolls
[0059] 116 recording
[0060] 118 radial guides
[0061] 134, 136 half shells
[0062] 138, 140 axial projections
Claims
Patent claims Method for assembling a stator (12) with a wave winding (10) which is arranged in slots of the stator and has winding heads projecting axially beyond a stator body, wherein toothed segments (14) held in a receptacle (16; 116) are provided between the slots, which are advanced radially outwards in accordance with the height of the wire layers during a linear feeding of the mat-like wave winding (10) and corresponding rotation of the receptacle (16; 116) and form the slots for wire webs (26) of the wave winding (10) between them, characterized in that during a first rotation of the receptacle (16; 116) only some of the toothed segments (14) are arranged in the receptacle (16; 116) and advanced radially outwards in accordance with the height of the inner wire layers and then during at least one subsequent rotation further toothed segments (14) are inserted into the receptacle (16;116) are inserted from the inside and advanced radially outwards, so that after the last rotation of the holder (16; 116) and the winding of the entire wave winding (10), all tooth segments (14) have been inserted and moved into their radial end position, or the last tooth segments (14) are finally inserted after winding and moved radially outwards. Method according to claim 1, characterized in that before the first rotation of the holder (16; 116), only every second tooth segment (14) is inserted into the holder (16; 116), or in a discontinuous sequence, only every second or third tooth segment (14) is inserted into the holder (16; 116). Method according to claim 1 or 2, characterized in that rounded or bevelled joining aids (20) are mounted on the radially outer tips of the tooth segments (14) before the tooth segments (14) are inserted into the holder (16;116). Method according to one of the preceding claims, characterized in that the receptacle (16; 116) is formed from two half-shells (34, 36; 134, 136) with axial projections (38, 40; 138, 140), wherein by means of the mutually facing projections (38, 40; 138, 140) between these radial guides (38; 138) for the toothed segments (14) are formed by the two half-shells (34, 36; 134, 136) being moved axially towards one another.
5. Method according to claim 4, characterized in that the distances between the axial projections (138, 140) are larger in the region of their axial ends, so that the widths of the guide grooves (138) can be adjusted by adjusting the axial position of the half-shells (134, 136) relative to one another, so that toothed segments (14) with a conical longitudinal section can be used, with which grooves with parallel groove flanks are produced.
6. Method according to one of the preceding claims, characterized in that a mounting device (38) with an adjustable link (40) is arranged in the receptacle, by means of which the toothed segments (14) are displaced radially outwards.
7. Method according to one of the preceding claims, characterized in that the tooth segments (14) are fed successively from a magazine to the holder (16; 116).
8. Method according to one of the preceding claims, characterized in that several rollers (42) are used for wire guidance, by means of which the wave winding (10) is deformed to the desired radius of the current winding position of the stator.
9. Method according to claim 8, characterized in that the rollers (42) are adjusted to a specific distance from the axis of rotation of the holder (16; 116) in accordance with the respective winding position.
10. Method according to one of the preceding claims, characterized in that tooth segments (14) are coated and / or insulated by primary forming processes.
11. Method according to one of the preceding claims, characterized in that after winding the wave winding (10) between the tooth segments (14) a stator yoke is pressed axially.
12. Method according to claim 11, characterized in that the holder is removed after the stator yoke has been pressed in. Multi-part stator having a plurality of individual teeth with parallel tooth flanks, between which a winding with winding heads is held, and a stator yoke, characterized in that the spacing of the teeth and their length are selected such that in the event of an imaginary radial displacement of the teeth, a collision of adjacent teeth would occur before the teeth would move out of the slots.