Stator of an electric machine

Abstract

The invention relates to a stator (1) of an electric machine, comprising a stator stack (2) formed by a plurality of stator sheets (3) arranged axially to one another. Wherein receptacles (6), which are spaced apart from one another in the circumferential direction (5) of the stator and pass through the stator stack at least in sections, are formed in the stator stack by means of recesses (4) in the stator sheets that are axially aligned with one another, and in each case at least one winding wire (7) of a stator winding (8) of the stator is accommodated in the respective receptacles. The receptacles each have at least one axially extending groove section (9) with a groove opening (10), the groove opening (10) penetrating the stator stack (2) radially internally in such a way that the groove section is open. Furthermore, the receptacles (6) each have at least one retaining section (11), via which an insulating insert (12) arranged in the respective receptacle (6) is radially fixed in the receptacle (6).

Description

Technical Field

[0001] This invention relates to a stator of an electric motor having a stator stack formed by a plurality of axially arranged stator laminations (sometimes called stator sheets), wherein accommodating portions spaced apart from each other in the circumferential direction of the stator and axially at least partially passing through the stator stack are formed in the stator stack via axially aligned notches in the stator laminations. At least one winding wire of a stator winding of the stator is respectively accommodated in each of the respective accommodating portions. Background Technology

[0002] Various embodiments of the stator of an electric motor, especially an electric motor (Elektromotoren, sometimes called an electric motor), are known in the prior art.

[0003] Thus, a stator for an electric motor, comprising stator laminations made of sheet metal blanks, can be obtained from DE 10 2021 112 931 A1. The sheet metal blanks, arranged relative to each other along the entire axial length of the stator laminations, have notches that, when viewed in a cross-section extending radially in the stator, are radially closed internally via bridging portions. Stator windings are disposed within the notches of the stator laminations. The bridging portions that radially close the corresponding notches are plastically deformed, i.e., mechanical stress is introduced therein.

[0004] US 2003 / 0 201 687 A1 also shows a stator of an electric motor having stator laminations and stator windings housed in recesses within the stator laminations. The recesses are also constructed such that, when viewed from the cross-section of the sheet metal blanks arranged relative to each other along the entire axial length of the stator laminations, they are radially closed internally via bridging portions in the cross-section extending in the radial direction of the stator.

[0005] However, this complete enclosure of the stator grooves negatively impacts its magnetic properties, and therefore negatively affects the efficiency of motors with such stators.

[0006] Furthermore, in motors, especially electric motors, electrical insulation of the conductors relative to the stator stack is typically achieved via grooved insulating paper, the conductors being particularly engaged in grooves within the stator stack and / or implemented, for example, as hairpins. The grooved insulating paper here separates the conductors from the metal grooves to prevent short circuits between the conductors and the stator stack. In addition to electrical insulation, the grooved insulating paper also provides mechanical protection. It protects the conductors from sharp edges or accidental contact with metal surfaces, which could damage them.

[0007] However, the use of grooved insulating paper in motors has some disadvantages, which can impair not only electrical insulation but also mechanical stability, and thus the reliability of the motor.

[0008] The problem here is that the conductor slips in the direction of the air gap or groove opening. If the conductor located in the stator groove moves in the direction of the air gap during motor operation due to mechanical and / or thermal loads, the air path (Luftstecke, sometimes called air distance) between the rotor and stator winding heads decreases. This can lead to dangerous electrical interference, or even short circuits, and impair motor efficiency. In extreme cases, it can even cause mechanical contact between components, leading to serious damage to the motor or even destruction.

[0009] Another problem arises from the tearing of the grooved insulation paper, particularly at its overlap with the inside of the groove and / or the air gap. When conductors, especially those implemented as hairpins, are joined into the groove, they are radially compressed against the grooved insulation paper, causing it to tear inwards, and the insulation effect at these locations is no longer fully guaranteed. The tearing also leads to other negative effects: on the one hand, it impairs the acoustic performance of the motor because the geometry of the grooved insulation paper, and if possible, its extension into the air gap, affects the air turbulence within the air gap. This can result in unwanted noise during motor operation. On the other hand, the tearing of the insulation paper can interfere with resin impregnation during conductor impregnation, resulting in inadequate impregnation of the conductor with insulating resin in all areas. This increases the risk of scrap, as insufficiently impregnated windings are less mechanically stable, and the electrical insulation is compromised.

[0010] An additional risk exists at the end: oil can intrude into the air gap due to the larger opening provided by the groove slot. This negatively impacts motor power due to the higher friction between the rotor and stator. Summary of the Invention

[0011] In this context, the present invention is based on the objective of implementing a stator of the type mentioned at the beginning, such that the electrical insulation and mechanical stability of the stator are improved, and thereby its magnetic properties are not impaired or are only slightly impaired.

[0012] This task is solved using a stator with features described below.

[0013] According to the present invention, a stator for an electric motor, particularly an electric motor, is provided, wherein the stator has a stator stack formed by a plurality of stator laminations, particularly sheet metal laminations, arranged axially relative to each other.

[0014] Here, in the stator stack, receiving portions are formed via axially aligned notches in the stator laminations, axially passing through and / or penetrating at least partially of the stator stack. These receiving portions are spaced evenly apart in the circumferential direction of the stator. Each receiving portion contains at least one winding wire from the stator winding.

[0015] Furthermore, according to the present invention, the receiving portion has at least one axially extending groove section with a groove opening or groove slot, and at least one retaining section, preferably at least two retaining sections.

[0016] Here, the groove opening passes radially inward through the stator stack in a manner that leaves the groove section open. Specifically, radially inward here means toward the inner circumference of the stator stack and / or opposite to the outer circumference of the stator stack. Furthermore, according to the invention, an insulating insert, arranged in the corresponding receiving portion and constructed, for example, as grooved insulating paper, is radially fixed in the receiving portion via said at least one retaining section. Here, the insulating insert electrically insulates the corresponding receiving portion relative to at least one winding wire of the stator winding, in particular.

[0017] By designing a suitable receiving portion (here, in the sense of a groove, via a corresponding groove section and a retaining section, preferably at least two retaining sections), the insulating insert can be advantageously fixed in the receiving portion, and thus the electrical insulation and mechanical stability of the stator can be improved. Furthermore, since the receiving portion is designed to be radially inwardly open as much as possible in the at least one groove section, the magnetic properties of the stator are unaffected or only slightly affected.

[0018] In a particularly advantageous improvement of the invention, the corresponding retaining section of the receiving portion is radially inward, i.e., on the inner circumferential side or at the inner circumference, and is closed via a bridging portion formed in the stator stack and extending in the circumferential direction. Closing the corresponding retaining section via the bridging portion (which thus secures the insulating insert and / or winding wire in the corresponding receiving portion) provides a particularly simple and advantageous implementation not only in terms of structure but also in terms of production.

[0019] Furthermore, an embodiment of the invention is advantageous if the corresponding retaining section of the receiving portion is radially inward, i.e., on the inner circumference side or at the inner circumference, and is formed only partially closed via a partially bridging portion extending in the circumferential direction, and forms a right angle with the radially extending receiving portion sidewall. By implementing the corresponding retaining section as a partially bridging portion, the influence of the retaining section on the stator's magnetic characteristics can be further minimized. Nevertheless, due to the right angle between the partially bridging portion and the receiving portion sidewall, reliable fixation of the insulating insert and / or winding wire can be advantageously ensured. Here, the partially bridging portion can extend partially from both receiving portion sidewalls, wherein a window can be arranged at the center of the partially bridging portion. However, alternatively, the partially bridging portion can also extend only from one receiving portion sidewall.

[0020] Furthermore, the design of the present invention can be considered advantageous if the width of the groove opening of the groove section corresponds to the groove width of the groove section. Since the groove section is irrelevant (sometimes referred to as important) to the positioning and / or fixing of the insulating insert and / or winding wire, a high degree of freedom can be ensured when designing the stator and / or the motor having the stator.

[0021] Furthermore, the improvement of the invention is advantageous if the retaining sections are implemented specifically only at the respective axial ends and / or end-side ends of the stator stack. Thus, even when the retaining sections are designed as bridging portions with closed retaining sections, the impact on the magnetic characteristics of the stator can be kept substantially minimal, while simultaneously ensuring the positional stability of the insulating inserts and / or winding wires. Moreover, since the retaining sections are implemented only at the axial ends, the assembly of the stator stack is also simplified.

[0022] Typically, however, in conjunction with the aforementioned improvements, an advantageous embodiment of the invention further comprises at least one retaining section, preferably at least two or more, axially constructed along the stator stack at its axial ends and / or end-sides. The arrangement of retaining sections, if possible, along the axial length of the stator stack ensures improved securing of the insulation inserts and / or winding wires. This ensures high mechanical stability, for example, during the operation of a motor with a stator, especially at high speeds or under mechanical loads. This minimizes vibration and potential wear. The distribution of multiple retaining sections along the stator further helps to minimize vibration and resonance. This results in quieter motor operation, which increases service life and reduces noise levels, especially during the operation of motors with stators.

[0023] Furthermore, in another highly advantageous embodiment of the invention, it is envisioned that the corresponding retaining section of the stator stack receiving portion is constructed via at least one stator lamination implemented as a retaining plate, wherein a retaining device extending in the circumferential direction and / or along the circumferential direction is formed radially inward, i.e., on the inner circumferential side or at the inner circumference, at a notch in which the retaining section is formed at least partially. Designing the retaining section directly into the stator lamination or retaining plate allows for cost-effective and structurally simple production. The retaining device can be integrated during stamping or forming, thereby eliminating the need for additional components or steps.

[0024] Also advantageously, in an improved embodiment of the invention, the retaining device is a bridging element that completely encloses the receiving portion of the retaining piece and constitutes at least one axial segment of the bridging portion of the retaining section. Therefore, the bridging element may form only a segment of the bridging portion, or the bridging portion may be entirely designed by a particularly unique retaining device.

[0025] Furthermore, in one design of the invention, the retaining device is configured as a partial bridging element that only partially closes the receiving portion of the retaining sheet and constructs at least one axial segment of the partial bridging portion of the retaining section. Therefore, the partial bridging element can also constitute only a segment of the partial bridging portion, or the partial bridging portion can be designed entirely from a particularly unique partial bridging segment. By implementing the partial bridging portion via a partial bridging segment formed in the retaining sheet, it is also feasible to integrate the forming of the retaining section into the production of the stator lamination (here, the retaining sheet), thereby omitting additional production steps.

[0026] In an advantageous manner, the corresponding grooved section of the stator stack receiving portion is, in one improvement, constructed via at least two, preferably more, stator plates arranged to each other, which are implemented as grooved plates. The recesses of the grooved sections, which at least proportionally form the receiving portion, have radial openings that are radially inward, i.e., on the inner circumferential side or at the inner circumference. These openings constitute the axial portion of the groove opening of the grooved section. By implementing the corresponding grooved sections via the stator or grooved plates, the grooved sections do not need to be introduced into the stator plates during installation, particularly by subtractive manufacturing methods (such as milling). Attached Figure Description

[0027] This invention allows for various embodiments. To further clarify its basic principles, some of these embodiments are illustrated in the accompanying drawings and described below. Drawings: exist Figure 1 The first embodiment of the stator with a retaining section at the axial end is shown; exist Figure 2 A highly simplified schematic diagram illustrates a first embodiment of the stator with a retaining section at the axial end; exist Figure 3 A highly simplified schematic diagram illustrates a second embodiment of the stator with retaining sections at the axial ends and within the stator; exist Figure 4 One embodiment of the retaining sheet is shown in the figure; exist Figure 5 One embodiment of the grooved plate is shown in the figure; exist Figure 6 The notch of the retaining piece with bridging elements is shown in the figure; exist Figure 7 The image shows a notch in a retaining piece with a partial bridging element; exist Figure 8 The figure shows a cross-sectional view of a stator stack with multiple housings; exist Figure 9 The image shows an electric motor with a stator and a rotor. Detailed Implementation

[0028] Figure 1 An embodiment of the invention is shown. Figure 9 A portion of the stator 1 of the motor 26 shown. The stator here has a stator stack 2 formed by a plurality of stator laminations 3 arranged axially to each other.

[0029] In the stator stack 2, receiving portions 6 are formed via axially aligned notches 4 in the stator laminations 3, which axially pass through and / or penetrate at least partially, and are particularly evenly spaced from each other in the circumferential direction 5 of the stator 1. Here, a plurality of winding wires 7 of the stator windings 8 of the stator 1 are respectively received and / or introduced into the respective receiving portions 6.

[0030] The receiving portion 6 formed in the stator stack 2 further has an axially extending grooved section 9 with a grooved opening 10 and two retaining sections 11. Here, the grooved opening 10 penetrates the stator stack 2 radially inward so that the grooved section 9 is open. In addition, an insulating insert 12, which is arranged in the respective receiving portion 6 and is constructed as grooved insulating paper, is radially fixed in the receiving portion 6 via the two retaining sections 11. This is achieved here by the fact that the respective retaining sections 11 of the receiving portion 6 are formed radially inward, that is, on the inner circumferential side and / or inner circumference of the stator stack 2, in a manner closed via a bridging portion 13 formed in the stator stack 2 and extending in the circumferential direction 5.

[0031] like Figure 1 China and in Figure 2 As shown very schematically again in these figures, in the implementation of stator 1 and / or stator stack 2, a retaining section 11 is provided at the corresponding axial end 18 of stator stack 2, thus designing a total of two retaining sections 11.

[0032] On the contrary, Figure 3 In another embodiment of the stator 1 and / or stator stack 2 shown, not only at the corresponding axial end 18 of the stator stack 2, but also away from the axial end 18 of the stator stack 2, three additional, in particular, retaining sections 11 are constructed along the axial direction of the stator stack 2. Thus, a total of five retaining sections 11 are implemented, which are axially spaced evenly from each other.

[0033] Figure 4 and Figure 5 Presented in Figures 1 to 3 The detailed design schemes of the retaining section 11 and the groove section 9 shown in the figure are illustrated, and respectively, the stator lamination 3 of the corresponding retaining section 11 or groove section 9 is shown, as well as the detailed illustration of the notch 4 of the stator lamination 3 with the winding wire 7.

[0034] From here Figure 4 It can be specifically learned from this that Figures 1 to 3 The stator stack 2 shown in the image has a retaining section 11 in the receiving portion 6 constructed via a stator plate 3 implemented as a retaining plate 19. Here, at the recess 4 of the retaining plate 19 forming the retaining section 11, a retaining device 20 extending radially inward, i.e., on the inner circumferential side and / or inner circumference of the retaining plate 19, is formed respectively, extending in and / or along the circumferential direction 5. The corresponding retaining device 20 is here a bridging element 21, which completely closes the corresponding recess 4 of the retaining plate 19. Because in Figures 1 to 3 In the implementation, the retaining section 11 is constructed by the retaining piece 19, therefore the corresponding retaining piece 19 itself is also constructed, for example... Figure 1 The bridging section 13 of the retaining section 11 is shown in the image.

[0035] from Figure 5 In addition, it was learned that Figures 1 to 3 The grooved section 9 of the receiving portion 6 of the stator stack 2 shown in the figure has a special design. Each grooved section 9 is composed of a plurality of stator plates 3 implemented as grooved plates 23. Figure 5 One of these recessed pieces 23 is shown exemplary in the image. The notch 4 of the recessed section 9 of the receiving portion 6, which is at least proportionally shaped, has an opening 24 radially inward, i.e., therefore on the inner circumferential side and / or inner circumference of the recessed piece 23. This opening is constructed, for example, in… Figure 1 The axial portion of the recessed opening 10 is presented in the recessed section 9. In this embodiment, the recessed opening 10 of the recessed section 9 and therefore the recessed opening width 16 of the opening 24 are smaller than the recessed width 17 of the recessed section 9. Consequently, adjacent to the opening 24, recessed feet 25 are formed in the circumferential direction 5 and / or extending along the circumferential direction 5, wherein these recessed feet 25, as particularly from the opening 24, are formed in the circumferential direction 5 and / or extending along the circumferential direction 5. Figure 5 As can be seen from the detailed diagram of the notch 4, it does not form a right angle with the receiving side wall 15 of the receiving part 6, but rather an obtuse angle.

[0036] However, the stator 1 can also be configured in an embodiment where the groove opening width 16 corresponds to the groove width 17. Conversely, in such an embodiment, the groove foot 25 is not formed.

[0037] from Figure 6 I learned again that I had been from Figure 4 The detailed diagram shows a known embodiment of the notch 4 of the retaining piece 19. Besides this design (in which the notch 4 of the retaining piece 19 is completely closed by the bridging element 21), there are other feasible implementations of the notch 4 of the retaining piece 19, which... Figure 7 show.

[0038] Specifically, from here Figure 7It is understood that a retaining device 20 extending in and / or along the circumferential direction 5 is formed radially inside the notch 4, i.e., on the inner circumference side and / or inner circumference of the retaining piece 19. This retaining device is a partial bridging element 22, which only partially closes the notch 4 of the retaining piece 19. If the retaining section 11 is implemented only by the retaining piece 19 having such a partial bridging section 22, then the partial bridging section 22 also constitutes the partial bridging portion 14 of the retaining section 11. Thus, the retaining section 11 of the receiving portion 6 is also formed in such a way that it is only partially closed by the partial bridging portion 14 extending in the circumferential direction 5. Here, the partial bridging portion 14 and the partial bridging section 22 that is thus also formed as the partial bridging portion 14 form a right angle with the radially extending receiving sidewall 15. This prevents the winding wire 7 and especially Figure 1 The sliding of the insulating insert 12 is shown in the image.

[0039] from Figure 8 and Figure 9 Furthermore, additional cross-sectional views of the stator stack 2 and / or stator 1 in the motor 26 having stator 1 can be obtained, particularly in... Figure 8 The image again shows multiple receiving portions 4 with retaining sections 11 and recessed sections 9. In addition to the stator 1, the motor 26, particularly implemented as an electric motor, also has a rotor 27, which can be drawn from... Figure 9 As we have learned.

[0040] Reference number list 1. Stator 2. Stator stack 3 stator laminations 4. Notch 5. Circumferential direction 6. Reception area 7. Winding wire 8 Stator windings 9. Groove section 10. Groove opening 11. Maintain section 12 Insulating inserts 13 Bridging section 14-part bridging section 15. Receiving section sidewall 16. Groove opening width 17. Groove width 18 Axial end 19 Keeping tablets 20 Holding devices 21 Bridging elements 22 bridging components 23 Grooved Plate 24 Opening 25 Groove foot 26 motors 27 Rotors

Claims

1. A stator (1) of an electric motor (26) having a stator stack (2) formed by a plurality of stator laminations (3) arranged axially relative to each other, wherein, In the stator stack (2), receiving portions (6) are formed in the circumferential direction (5) of the stator (1) via axially aligned notches (4) in the stator laminations (3), which are spaced apart from each other and axially pass through at least partially sections of the stator stack (2), and at least one winding wire (7) of the stator winding (8) of the stator (1) is respectively received in the respective receiving portions (6). The receiving portions (6) are characterized in that each has at least one axially extending groove section (9) with a groove opening (10), wherein the groove opening (10) passes radially inward through the stator stack (2) in such a way as to open the groove section (9) and each has at least one retaining section (11), and an insulating insert (12) arranged in the respective receiving portion (6) is radially fixed in the receiving portion (6) via the retaining section.

2. The stator (1) according to claim 1, characterized in that, The corresponding retaining section (11) of the receiving portion (6) is radially inwardly formed to close via a bridging portion (13) formed in the stator stack (2) and extending in the circumferential direction (5).

3. The stator (1) according to claim 1 or 2, characterized in that, The corresponding retaining section (11) of the receiving portion (6) is radially inwardly formed in a manner that is only partially closed via a partial bridging portion (14) extending in the circumferential direction (5), wherein at least the partial bridging portion (14) forms a right angle with the radially extending sidewall (15) of the receiving portion.

4. The stator (1) according to at least one of the preceding claims, characterized in that, The groove opening width (16) of the groove opening (10) of the groove section (9) corresponds to the groove width (17) of the groove section (9).

5. The stator (1) according to at least one of the preceding claims, characterized in that, A retaining section (11) is provided at the corresponding axial end (18) of the stator stack (2).

6. The stator (1) according to at least one of the preceding claims, characterized in that, The axial end (18) away from the stator stack (2) is axially constructed with at least one retaining section (11) along the stator stack (2).

7. The stator (1) according to at least one of the preceding claims, characterized in that, The retaining section (11) of the receiving portion (6) of the stator stack (2) is constructed via at least one stator piece (3) implemented as a retaining piece (19), and a retaining device (20) extending in and / or along the circumferential direction (5) is radially formed inside at the notch (4) of the retaining section (11) which is formed in at least a partial section therein.

8. The stator (1) according to at least one of the preceding claims, characterized in that, The retaining device (20) is a bridging element (21) that completely encloses the receiving portion (6) of the retaining piece (19) and constructs at least one axial segment of the bridging portion (13) of the retaining section (11).

9. The stator (1) according to at least one of the preceding claims, characterized in that, The retaining device (20) is a partial bridging element (22) that partially closes the receiving portion (6) of the retaining piece (19) and constructs at least one axial segment of the partial bridging portion (14) of the retaining section (11).

10. The stator (1) according to at least one of the preceding claims, characterized in that, The recessed section (9) of the receiving portion (6) of the stator stack (2) is constructed via at least two, preferably more, stator plates (3) arranged to each other as recessed pieces (23), which at least proportionally form the notch (4) of the recessed section (9) of the receiving portion (6) having an opening (24) radially inside, the opening forming the axial portion of the recessed opening (10).

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