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EP-4742502-A1 - STATOR OF AN ELECTRIC MACHINE

EP4742502A1EP 4742502 A1EP4742502 A1EP 4742502A1EP-4742502-A1

Abstract

The invention relates to a stator (1) of an electric machine with a stator core (2) consisting of a plurality of axially arranged stator laminations (3), wherein, in the stator core (2), recesses (6) are formed in the stator laminations (3) spaced apart from each other in the circumferential direction (5) of the stator (1), and which extend axially through the stator core (2) at least partially, and in each recess (6) at least one winding wire (7) of a stator winding (8) of the stator (1) is received. The recesses (6) each have at least one axially extending groove section (9) with a groove opening (10), wherein the groove opening (10), opening the groove section (9), penetrates the stator core (2) radially inwards. Furthermore, the receptacles (6) each have at least one retaining section (11) by which an insulating insert (12) arranged in a respective receptacle (6) is radially fixed in the receptacle (6).

Inventors

  • Weber, Jan-Niklas
  • KOCH, JOHANNES
  • PROKOPH, STEFAN

Assignees

  • Volkswagen Aktiengesellschaft

Dates

Publication Date
20260513
Application Date
20251106

Claims (10)

  1. Stator (1) of an electrical machine (26) with a stator core (2) consisting of a plurality of axially arranged stator laminations (3), wherein the stator core (2) has recesses (6) spaced apart from each other in the circumferential direction (5) of the stator (1) and extending axially through the stator core (2) at least partially, and each recess (6) accommodates at least one winding wire (7) of a stator winding (8) of the stator (1), characterized in that the recesses (6) each have at least one axially extending slot section (9) with a slot opening (10), wherein the slot opening (10), opening the slot section (9), extends radially inwards through the stator core (2) and each has at least one retaining section (11) by which an insulating insert (12) arranged in a respective recess (6) is radially fixed in the recess (6).
  2. Stator (1) according to claim 1, characterized in that a respective retaining section (11) of the receptacles (6) is formed radially inside via a web (13) formed in the stator stack (2) and extending in the circumferential direction (5).
  3. Stator (1) according to claims 1 or 2, characterized in that a respective retaining section (11) of the receptacles (6) is only partially closed radially inside over a partial web (14) extending in the circumferential direction (5), wherein at least the partial web (14) forms a right angle with the radially extending receptacle side walls (15).
  4. Stator (1) according to at least one of the preceding claims, characterized in that a groove opening width (16) of a groove opening (10) of a groove section (9) corresponds to a groove width (17) of this groove section (9).
  5. Stator (1) according to at least one of the preceding claims, characterized in that a retaining section (11) is provided at each axial end (18) of the stator stack (2).
  6. Stator (1) according to at least one of the preceding claims, characterized in that at least one retaining section (11) is formed axially along the stator stack (2) away from the axial ends (18) of the stator stack (2).
  7. Stator (1) according to at least one of the preceding claims, characterized in that a retaining section (11) of the receptacles (6) of the stator stack (2) is formed over at least one stator lamella (3) designed as a retaining lamella (19), on the recesses (4) of which, forming a retaining section (11) at least section by section, a retaining means (20) extending in and/or along the circumferential direction (5) is formed radially inside.
  8. Stator (1) according to at least one of the preceding claims, characterized in that the retaining means (20) is a web element (21) which completely closes a receptacle (6) of a retaining lamella (19) and forms at least one axial segment of a web (13) of a retaining section (11).
  9. Stator (1) according to at least one of the preceding claims, characterized in that the retaining means (20) is a partial web element (22) which only partially closes a receptacle (6) of a retaining lamella (19) and forms at least an axial segment of a partial web (14) of a retaining section (11).
  10. Stator (1) according to at least one of the preceding claims, characterized in that a groove section (9) of the receptacles (6) of the stator stack (2) is formed over at least two, preferably several, stator lamellae (3) arranged in series as groove lamellae (23), the recesses (4) of which form at least a portion of a groove section (9) of a receptacle (6) have a radially inward opening (24) which forms an axial segment of a groove opening (10).

Description

The invention relates to a stator of an electric machine with a stator core consisting of a plurality of axially arranged stator laminations, wherein axially aligned recesses in the stator laminations form recesses spaced apart from each other in the circumferential direction of the stator, which extend axially through the stator core at least partially. Each recess accommodates at least one winding wire of a stator winding of the stator. Various designs of stators for electrical machines, especially electric motors, are known in the prior art. So is the DE 10 2021 112 931 A1 The stator of an electric machine is to be removed, consisting of a stator core made of sheet metal blanks. These sheet metal blanks, arranged in a row along the entire axial length of the stator core, have recesses that, viewed in a cross-section extending radially along the stator, are closed radially on the inside by a web. The stator windings are housed in the recesses of the stator core. The web that closes each recess radially on the inside is plastically deformed in such a way that a mechanical stress is introduced into it. Even the US 2003 / 0 201 687 A1 Figure 1 shows a stator of an electric machine with a stator lamination stack and stator windings that are received in recesses of the stator lamination stack. The recesses are designed such that, in the lamination sections arranged along the entire axial length of the stator lamination stack, they are each radially closed on the inside by a web in a cross-section extending in the radial direction of the stator. However, such a complete closure of the stator slots has a negative impact on its magnetic properties and thus negatively on the efficiency of an electric machine having such a stator. In an electric machine, particularly an electric motor, the electrical insulation of the conductors, which are typically inserted into the slots of the stator core and/or configured as hairpins, is usually achieved using slot insulation paper. This paper separates the conductors from the metallic slots to prevent short circuits between the conductors and the stator core. In addition to electrical insulation, the slot insulation paper also provides mechanical protection. It protects the conductors from sharp edges or unintentional contact with metallic surfaces that could damage them. However, the use of slot insulation paper in electrical machines has some disadvantages that can affect both the electrical insulation and the mechanical stability, and therefore the reliability of the electric motor. One problem is the conductors slipping towards the air gap or the slot. If the conductors located in the stator slots migrate towards the air gap due to mechanical and/or thermal stresses during operation of the electric motor, the intended air gap between the rotor and the stator winding head is reduced. This can lead to dangerous electrical interference or even short circuits and impair the motor's efficiency. In extreme cases, mechanical contact between the components can even occur, resulting in serious damage to the electric motor, potentially leading to its destruction. Another problem arises from the gapping of the slot insulation paper, especially at overlaps on the inside of the slot and/or the air gap. When the conductors, particularly those designed as hairpins, are inserted into the slots, they press radially against the slot insulation paper, causing it to gape inwards and compromising the insulation effect at these points. This gapping also leads to further negative effects: Firstly, it impairs the acoustics of the electric motor, as air turbulence in the air gap is affected by the altered geometry of the slot insulation paper and its potential protrusion into the air gap. This can lead to unwanted noise during motor operation. Secondly, the gapping of the insulation paper can disrupt the resin impregnation process, potentially resulting in incomplete impregnation of the conductors. This increases the risk of rejects, as insufficient resin is used. Impregnated windings are mechanically less stable and the electrical insulation is impaired. At the front, there is an additional risk of oil penetrating the air gap, as the slotted sections offer larger openings. Due to increased friction between the rotor and stator, this negatively impacts the motor's performance. Against this background, the invention is based on the objective of designing the stator of the type mentioned above in such a way that the electrical insulation as well as the mechanical stability of the stator are improved and its magnetic properties are not affected or are only affected to a very minor extent. This problem is solved with a stator according to the features of claim 1. The dependent claims relate to particularly advantageous further developments of the invention. According to the invention, a stator of an electrical machine, in particular an electric motor, is provided, wherein the stator comprises a stato