Method for introducing an insulating film and at least one electrical conductor into at least one slot of a stator of an electrical machine
The use of a spacer element in the stator slot method addresses the issue of insulating film overlap, enhancing conductor placement and cooling, and improving design flexibility in electrical machines.
Patent Information
- Application Number
- DE102024134631
- Authority / Receiving Office
- DE · DE
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2024-01-19
- Filing Date
- 2024-11-25
- Publication Date
- 2025-08-07
AI Technical Summary
Existing methods for inserting insulating film and electrical conductors into stator slots result in significant overlap of the insulating film, which complicates conductor fastening and increases material usage, while also limiting design flexibility and cooling options.
A method involving a spacer element is used to temporarily position the insulating film, allowing controlled introduction and folding of the film legs without overlap, enabling precise conductor placement and reduced film length.
Reduces insulating film overlap, enhances conductor accessibility, improves design freedom, and facilitates better cooling, while potentially increasing machine power or reducing volume.
Smart Images
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Abstract
Description
Field of the invention
[0001] The present invention relates to a method for introducing an insulating film and at least one electrical conductor into at least one slot of a stator of an electrical machine using a spacer element. State of the art
[0002] Electrical conductors in electrical machines are typically inserted into the slots of a stator and insulated from the stator with an insulating foil. This so-called slot base insulation not only provides electrical insulation but also mechanically protects the electrical conductor from sharp edges of the laminated core. The insulating foil protrudes from the slot during production. This extension remains until the last electrical conductor passes the edge of the respective slot opening of the stator.
[0003] As a rule, after the last electrical conductor has been inserted, the insulating film must be folded in an overlapping manner in the direction of the electrical conductors in the area of the slot opening side in order to create space for the insertion of a conductor fastening element, for example a fastening wedge, in the slot.
[0004] The conductor-free distance to the slot opening and the type of winding or its method of insertion generally determine the length of the end pieces of the insulating foil and their overlap after folding. Summary of the invention
[0005] It is an object of the invention to provide an improved method for introducing an insulating film and at least one electrical conductor into a slot of a stator of an electrical machine, which method enables a defined, as little as possible or no overlap of the insulating film during folding.
[0006] This need can be met by the subject matter of the present invention according to independent claim 1. Advantageous embodiments of the present invention are described in the dependent claims.
[0007] The method according to the invention serves to introduce an insulating film and at least one electrical conductor, preferably several electrical conductors, into at least one slot of a stator of an electrical machine.
[0008] According to the invention, the method comprises at least the following steps: - axial or radial insertion of a spacer element into the groove so that the spacer element rests against a groove base of the groove; - radially inserting the insulating film into the groove until the insulating film rests against the spacer element and a right leg of the insulating film rests against a right groove edge and a left leg of the insulating film rests against a left groove edge of the groove, wherein the respective legs of the insulating film extend radially beyond the respective groove edge in the region of a groove opening of the groove; - radial insertion of the electrical conductor into the groove until it rests against the insulating foil in the area of the spacer element; - axial removal of the spacer element; - further radial insertion of the electrical conductor and thus the insulating foil into the groove until the insulating foil rests against the base of the groove; - Fold the legs of the insulating foil in the area of the slot opening in the direction of the electrical conductor.
[0009] The direction “axial” corresponds to a direction along or parallel to a central longitudinal axis of the stator of the electrical machine, more precisely a laminated core of the stator of the electrical machine.
[0010] The direction “radial” corresponds to a direction normal to the central longitudinal axis of the stator of the electrical machine, more precisely the laminated core of the stator of the electrical machine.
[0011] By inserting a temporary spacer between the groove base and the insulating film, the position of the insulating film in the groove can be temporarily and deliberately influenced. Furthermore, the insulating film can be held in position during the insertion of at least one electrical conductor. The spacer remains in the groove until all electrical conductors are securely contained within the groove and thus within the insulating film. Once this is achieved, the spacer is removed, and the electrical conductor and insulating film are pushed to the slot base.
[0012] The spacer element can be made of any material and designed in any shape, as long as the functions described above are fulfilled. The spacer element can be a single element that extends over the entire axial extent ("length") of a stator core of the stator or over the entire axial extent ("length") of the stator slot. However, the spacer element can also be designed as a double element that is inserted into the slot from both sides of the stator core of the stator. Furthermore, the spacer element can extend over the entire length or only over a partial length of the stator core of the stator. The spacer element can also be formed as a bundle of individual elements that can be inserted separately or in groups, or as a cage-like structure.
[0013] The two legs of the insulating foil are preferably designed in their radial extension such that they are folded in the direction of the electrical conductor without overlapping each other. However, in a further embodiment, they can also be designed such that they are folded in the direction of the electrical conductor without overlapping each other.
[0014] Furthermore, an axially extending recess is preferably formed in the region of the groove opening of the groove, into which a fastening element is axially inserted after the legs of the insulating film have been folded.
[0015] The method according to the invention enables a reduction in the length of the insulating foil's legs while retaining its full desired functionality. Furthermore, the method according to the invention enables better control over the degree of overlap of the insulating foil.
[0016] The method according to the invention thus creates a new degree of freedom in the design, relating to the length of the portion of the insulating foil legs protruding from the slot. The introduction of the spacer element makes it possible to reduce the saturation of the magnetic flux in the rear yoke of the stator, which means that either the power of the electric machine can be increased or its volume can be reduced. This can also lead to the following results: - Change in slot capacity, which directly affects the bearing currents in the system. - Reduced consumption of insulation film, resulting in cost savings in large-scale production. - Direct access to the electrical conductor near the slot opening, as the overlap of the insulating foil legs can be significantly reduced or eliminated. This allows for the use of more advantageous cooling options. Brief description of the drawings
[0017] The invention is described below by way of example with reference to the drawings. Fig. 1a - Fig. 1f shows a schematic flow diagram of a method for introducing an insulating foil and an electrical conductor into a slot of a stator of an electrical machine. Fig. 2a - 2d shows a difference between a conventional method and a method according to the invention. Detailed description of the invention
[0018] In Fig. 1a to Fig. 1f shows a plan view of a slot 4 of a stator 5 of an electrical machine.
[0019] The groove 4 is formed in a laminated core 5a of the stator 5 and has a recess 13 in the region of a groove opening 12 for receiving a fastening element 14.
[0020] In Fig. 1a to Fig. 1f is a step-by-step process of the method 1 according to the invention - in particular, the insertion of windings as electrical conductors 3 into the slot 4 of the stator 5, wherein the slot 4 is lined with an insulating film 2, is shown.
[0021] In Fig. 1a, a spacer element 6 and an insulating foil 2 have already been inserted into the groove.
[0022] The spacer element 6 was inserted axially into the groove 4 in such a way that it rests against a groove base 7 of the groove 4.
[0023] The insulating film 2 was inserted radially into the groove 4 until it rests against the spacer element 6 and a right leg 8 of the insulating film 2 rests against a right groove edge 9 and a left leg 10 of the insulating film 2 rests against a left groove edge 11 of the groove 4. The two legs 8, 10 of the insulating film 2 extend radially beyond the respective groove edge 9, 11 in the region of a groove opening 12 of the groove 4.
[0024] In Fig. 1b shows a radial insertion of the electrical conductors 3 into the groove 4 and thus into the insulating film 2.
[0025] The electrical conductors 3 are inserted into the groove 4 until they touch or abut the insulating foil 2 in the area of the spacer element 6 ( Fig. 1c).
[0026] This is followed by an axial removal of the spacer element 6 and a further radial insertion of the electrical conductors 3 and thus of the insulating film 2 into the groove 4 until the insulating film 2 rests against the groove base 7 of the groove 4 ( Fig. 1d).
[0027] In Fig. 1e shows the folding of the legs 8, 10 of the insulating foil 2 in the area of the slot opening 12, i.e., on the slot opening side of the slot 4, in the direction of the electrical conductors 3. The legs 8, 10 are folded along a respective fold point 15.
[0028] Finally, a fastening element 14 for fastening the electrical conductors in the groove 4 is inserted axially into the recess 13 ( Fig. 1f).
[0029] In Fig. 2a to 2d, a conventional, already known, method is compared with the method 1 according to the invention - the comparison illustrates the resulting difference with regard to the insulating film 2. In Fig. 2a and Fig. 2b shows that the length of the legs 8, 10 of the insulating film 2 is reduced after the respective fold point 15 by the introduction of the spacer element 6, while the original length of the legs 8, 10 outside the groove 4 is maintained. The reduction in the length of the legs 8, 10 is a function of the spacer element 6 temporarily inserted into the groove 4. With increasing height (radial extension) of the spacer element 6, the length of the legs 8, 10 of the insulating film 2 decreases. The dimensions and shape of the spacer element 6 are not specified. The only condition is that the insulating film 2 remains in place until the last electrical conductor 3 is inserted into the groove 4 and thus into the insulating film 2, before the spacer element 6 is removed and the electrical conductors 3 are pressed into their final position. Fig. 2c and Fig. 2d show a possible difference in the folding of the legs 8, 10 of the insulating foil 2, where Fig. 2c the result from the conventional, already known procedure and Fig. 2d shows the result of the method 1 according to the invention. List of reference symbols 1 procedure 2 insulating foil 3 Electrical conductor 4 grooves 5 Stator 5a (stator) laminated core 6 spacer element 7 Groove base 8 Right thigh 9 Right groove edge 10 Left thigh 11 Left groove edge 12 Groove opening 13 Recess 14 Fastening element 15 folding point
Claims
[1] Method (1) for introducing an insulating film (2) and at least one electrical conductor (3) into at least one groove (4) of a stator (5) of an electrical machine, at least comprising the following steps: - axially or radially inserting a spacer element (6) into the groove (4) so that the spacer element (6) bears against a groove base (7) of the groove (4); - radially inserting the insulating film (2) into the groove (4) until the insulating film (2) rests against the spacer element (6) and a right leg (8) of the insulating film (2) rests against a right groove edge (9) and a left leg (10) of the insulating film (2) rests against a left groove edge (11) of the groove (4), wherein the respective legs (8, 10) of the insulating film (2) extend radially beyond the respective groove edge (9, 11) in the region of a groove opening (12) of the groove (4); - radial insertion of the electrical conductor (3) into the groove (4) until it rests against the insulating film (2) in the region of the spacer element (6); - axial removal of the spacer element (6); - further radial insertion of the electrical conductor (3) and thus of the insulating film (2) into the groove (4) until the insulating film (2) rests against the groove base (7) of the groove (4); - Folding the legs (8, 10) of the insulating foil (2) in the area of the groove opening (12) in the direction of the electrical conductor (3). [2] Method (1) according to claim 1, characterized by that the two legs (8, 10) of the insulating film (2) are designed in their radial extension such that they are folded overlapping one another or not overlapping one another. [3] Method according to claim 1 or 2, characterized bythat in the region of the groove opening (12) of the groove (4) an axially extending recess (13) is formed, into which a fastening element (14) is axially inserted after the legs (8, 10) of the insulating film (2) have been folded.