WO2022109647A1 - Machine component for an electric machine - Google Patents

Abstract

The invention relates to a machine component (1) for an electric machine, comprising a component body (2) in which grooves (4) are formed, electrical conductors (7) being arranged in the grooves (4), which electrical conductors project out of the groove (4) at axial ends of the grooves (4) and which cross one another in at least one projecting region, and in the region outside the grooves, the electrical conductors (7) being insulated with respect to one another with additional insulating elements (12), the additional insulating elements (12) being arranged exclusively between the electrical conductors (7).

Description

MACHINE COMPONENT FOR AN ELECTRICAL MACHINE

The invention relates to a machine component for an electrical machine, comprising a component body in which slots are formed, electrical conductors being arranged in the slots, which protrude from the slots at axial ends of the slots and are arranged crossing one another in at least one protruding area , and wherein the electrical conductors are electrically isolated from one another in the area outside the grooves with additional insulating elements.

The invention further relates to an electrical machine comprising a stator and a rotor.

In addition, the invention relates to a method for producing a machine component for an electrical machine by providing a component body in which grooves are formed, electrical conductors being arranged in the grooves in such a way that they protrude from the grooves at axial ends of the grooves, and in are arranged crossing one another in at least one protruding area, and the electrical conductors are electrically insulated from one another in the area outside the grooves with additional insulating elements.

Appropriate insulation must be provided so that in a stator or a rotor of an electrical machine the voltage and partial discharge resistance between two intersecting form bars of a plug-in winding with different phase in the end winding can be met. Since this insulation thickness is often not required in the slot and this insulation thickness has a significantly negative effect on the copper fill factor, it is advantageous to implement a lower insulation thickness in the slot depending on the maximum voltage differences that occur between two adjacent conductors. Additional insulating elements are attached to the windings outside the slot to increase the insulation strength.

Such an embodiment is described, for example, in DE11 2013 004258 T5. From this document, a rotary electric machine is known, containing an armature with an annular armature core, in which grooves are arranged on the circumference; and an armature winding attached to the armature core, the armature winding including a plurality of winding skörpem, each formed by winding a conductor wire having an insulating coating is formed, and insulating members, which is different from the insulating coating.

EP 1 401 085 A2 describes an electric motor, comprising: a stator core with slots; coils arranged along the slots of the stator core to form coil edges projecting from the ends of the stator core; and insulating sheets for insulating proximal portions of the coil edges, each of the insulating sheets having a wrapping portion for folding over one or more coils of the same phase and inserting portions inserted into a slot or slots of the stator core.

The invention is based on the object of improving a component having an electrical winding.

In the case of the machine component mentioned at the outset, the object of the invention is achieved in that the additional insulating elements are arranged exclusively between the electrical conductors.

In addition, the object of the invention is achieved with the electrical machine mentioned at the outset, which includes the machine component according to the invention.

Furthermore, the invention is achieved with the method mentioned at the outset, according to which it is provided that the additional insulating elements are arranged exclusively between the electrical conductors.

The advantage here is that, despite the use of additional electrical insulation, the machine component can be kept compact, since the additional insulating elements are only used where this is advantageous for improving voltage and partial discharge resistance. In comparison to the prior art mentioned above, the additional insulating elements are therefore no longer arranged around the entire circumference of the electrical conductors. In addition to the electrical effectiveness of the additional insulating elements, an improvement in the mechanical strength of the end winding of the mechanical engineering part can also be achieved. In addition, with the arrangement of the additional insulating elements exclusively between the electrical conductors, a cost reduction can be achieved due to the lower material consumption. The copper fill factor can also be increased by reducing the insulation material. In addition, with the arrangement of the additional electrical insulating elements exclusively between the electrical conductors, improved cooling of the winding overhang can be achieved, since the coolant can flow better around the electrical conductors in the winding overhang, and in particular can also flow or penetrate between the electrical conductors.

To further improve the reduced installation space requirement, according to a preferred embodiment variant of the invention, it can be provided that the additional insulating elements are designed in the form of strips. It is thus possible to arrange the insulating elements exclusively along the electrical conductors.

According to a further embodiment of the invention, it is also advantageous if the additional insulating elements are arranged adhering to the surfaces of electrical conductors, since the surface area can be reduced due to the reduced risk of the additional insulating elements slipping.

According to another embodiment variant of the invention, a further reduction in the space requirement can be achieved in that the number of additional insulating elements corresponds at most to half the number of electrical conductors.

Also to reduce installation space, according to one embodiment variant of the invention, it can be provided that the additional insulating elements have a maximum layer thickness of 400 μm.

In order to simplify the arrangement of the additional insulating elements, it can be provided according to a further embodiment of the invention that the electrical conductors are designed as shaped rods with an at least approximately square cross section.

According to another embodiment of the invention, provision is preferably made for only one additional insulating element to be arranged between two electrical conductors in each case. So not every electrical conductor has an additional insulating element in the crossing area, but the additional insulating elements can be arranged on only one of two layers of the electrical conductors lying one above the other. It is thus also a simplification of the assembly of the end winding can be achieved, since a larger proportion of electrical conductors are not equipped with the additional insulating elements, which means that processing time can be saved. According to one embodiment variant of the invention, the additional insulating elements are preferably arranged between electrical conductors lying one above the other and/or next to one another.

For a better understanding of the invention, it is explained in more detail with reference to the following figures.

They each show in a simplified, schematic representation:

Fig. 1 shows a machine component with a part of electrical conductors in an oblique view;

FIG. 2 shows the machine compartment according to FIG. 1 in side view;

3 shows a section of the machine component in the region of the end winding;

4 shows a section of an embodiment variant of a machine component in the area of the end winding.

As an introduction, it should be noted that in the differently described embodiments, the same parts are provided with the same reference numbers or the same component designations, and the disclosures contained throughout the description can be transferred to the same parts with the same reference numbers or the same component designations. The position information chosen in the description, such as top, bottom, side, etc., is related to the directly described and illustrated figure and these position information are to be transferred to the new position in the event of a change of position.

1 to 3 show a machine component 1 for an electrical machine. The electrical machine is in particular a motor, but can also be designed differently, such as example as a generator. The machine component 1 can in particular be a stator or a rotor of the electric machine, it being possible for the machine component 1 to form both the stator and the rotor of an electric machine.

The shown in Figs. 1 to 3 machine component 1 is designed as a stator of the electrical Ma machine. The following statements must therefore be adapted accordingly, if the machine component 1 is designed as a rotor. Since this adaptation, such as the arrangement of grooves, is known to a person skilled in the art, it is not specifically pointed out below. These adaptations should therefore be read along.

The machine component 1 has a component body 2 . The component body 2 is in particular a laminated core, but can also be designed differently. In the embodiment variant shown, the component body 2 has the shape of a hollow cylinder. In the component body 2 ne are distributed next to each other in a circumferential direction 3 grooves 4 are formed. Beginning at an inner surface 5, the grooves 4 extend radially outward. The grooves 4 extend through the entire component body 2 in the direction of a central longitudinal axis 6 (rotational axis).

Electrical conductors 7 are arranged in the grooves 4, in particular plugged in. Only one electrical conductor 7 can be arranged per slot 4 . Preferably, however, there are several electrical conductors 7 per slot 4, which can also be seen in FIG. However, it should be pointed out that, for better understanding, only some of the electrical conductors 7 are shown in FIG. 1 as an example.

The component body 2 has a first end face 8 and a second end face 9 opposite this in the direction of the longitudinal center axis 6 .

The electrical conductors 7 have conductor ends 10 with which they protrude from the grooves 7 at the axial end of the grooves 7, which are each formed in the end faces 8, 9. The Lei terenden 10 of the same phases are brought together. This can be done, for example, by further bending the conductor ends 10 so that the conductor ends 10 extend from one slot 7 to another slot 7 (phase-dependent), as shown in FIG. However, it is also possible for the conductor ends 10 to have end regions 11 at which two conductor ends 10 abut one another depending on the phase in order to be electrically conductively connected to one another in these end regions 11, in particular with a material bond, as shown in FIG Section of an embodiment of the machine component 1 shows.

To form a compact winding/arrangement of the electrical conductors 7 (ie a compact end winding), the conductor ends 10 are reversed in and against the circumferential direction 3 bow. The specific design of the winding is dependent on the desired winding scheme, which can vary depending on the design of the machine component 1. Such winding schemes are known from the prior art, so that they will not be discussed further in order to avoid repetition. Reference is therefore made to the relevant prior art.

By bending the conductor ends 10, the conductor ends 10 cross over (as can be seen from Figs. 1 to 4), which means there is a risk of mutual contact. In order to prevent this, the electrical conductors 7, which are already provided with electrical insulation on the outside, are provided with additional insulating elements 12 in the region of the conductor ends, as can best be seen in FIGS. 3 and 4. In contrast to the prior art, these additional insulating elements 12 (also referred to as phase insulation or winding head insulation) are not designed or arranged in the form of sleeves, but are arranged exclusively between the electrical conductors 7 . In other words, at least the radially outermost surfaces 13 of the radially outermost layer 14 and the radially innermost surfaces of the radially innermost bearings of the electrical conductors 7 are free of the additional electrical insulating elements 12.

The additional insulating element 12 can be arranged between two electrical conductors 7 lying one above the other in the radial direction (as shown in Figs. 3 and 4) and/or between electrical conductors 7 which lie directly next to one another in a layer of electrical conductors 7 of the same radial height , be provided. The additional insulating elements 12 are therefore provided in the so-called end winding between electrical conductors 7 of different phases.

It should be pointed out in this context that electrical insulating elements, for example made of paper, are usually also provided in the grooves 7 . It can be seen that the additional electrical insulating elements 12 form part of the electrical insulating elements in the grooves 7 . However, the additional electrical insulating elements 12 are preferably provided in addition to the existing or used electrical insulation of the electrical conductors 7 in the groove area.

The additional insulating elements 12 can extend over at least approximately the entire area of the electrical conductors 7 bent obliquely with respect to the circumferential direction 3, with this area preferably covering the entire area of overlap of each other crossing conductor ends 10 of the electrical conductors 7 covers. However, the additional insulating elements 12 can also be limited to the crossing regions of the electrical conductors 7 crossing one another, or they can extend beyond the conductor ends 10 into the slots 7 and form part of the slot insulation there. However, the latter is not the preferred variant if a smaller layer thickness of insulating material is sufficient for the slot insulation than in the area of the conductor ends 10.

The layer thickness of the additional insulating elements 12 can in particular be a maximum of 400 mhi, in particular between 80 mhi and 300 mhi.

In principle, the additional insulating elements 12 consist of any suitable material. For example, they can be made of a polyamide, a polyimide, PEEK, PPS, PPSU, PESU, PAI, PEI, PTFE, mica, or a material combination of similar electrically insulating materials.

The additional insulating elements 12 preferably have an adhesive layer, so that they can be arranged on the surface of the electrical conductors 7 in an adhesive manner.

In the preferred embodiment variant, the additional insulating elements 12 are designed in the form of strips, for example made from an adhesive tape.

According to a further embodiment variant, it can be provided that the number of additional insulating elements 12 corresponds to a maximum of half the number of electrical conductors 7 . In particular, the number of additional insulating elements 12 can be between N/2 and N/9, where N is the total number of electrical conductor ends 10 that protrude from the grooves 4.

It can preferably be provided that the respective radially outer surfaces of the radially inner layer of electrical conductors 7 of crossing electrical conductors 7 are provided with the additional insulating elements 12 . However, it is also possible for the radially inner surfaces of the respective radially outer layer of electrical conductors 7 to be provided with the additional insulating elements 12 .

It is also possible that both the radially outer surface of the inner layer of electrical's conductors 7 and the radially inner surfaces of the radially outer layer of electrical Leitem 7 are provided with the additional insulating elements 12. In the preferred embodiment variant of the machine component, however, it is provided that only one additional insulating element 12 is arranged between each two electrical conductors 7 .

In the preferred embodiment variant, the electrical conductors 7 are designed as shaped rods with an at least approximately square cross section (as so-called hairpins). However, the electrical conductor's 7 can also have a round cross-section.

The additional electrical insulating elements 12 are preferably no wider than the electrical conductors 7 at the surface on which the electrical insulating elements 12 are arranged, as can be seen from FIGS. 3 and 4. FIG.

Furthermore, the electrical insulating elements 12 are preferably embodied as strips which are arranged inclined between the conductors in the circumferential direction. The angle of inclination depends on the electrical conductors 7. If these are arranged to run in the direction of the longitudinal center axis 6, the strip-shaped additional insulating elements 12 also run in this direction (ie at an angle of 90 ^° to the circumferential direction). If the electrical conductors 7 are inclined in relation to the circumferential direction 3, the additional insulating elements 12 also follow this inclination. In general, it can therefore be said that the electrical insulating elements are preferably arranged following the course of the electrical conductors 7 in the conductor ends 10 .

In the preferred embodiment variant, the invention provides in particular that the phase insulation is preferably implemented on one side and separately for each electrical conductor 7 by means of a strip.

The exemplary embodiments show or describe possible embodiment variants, it being noted at this point that various combinations of the individual embodiment variants with one another are also possible.

Finally, for the sake of clarity, it should be pointed out that, for a better understanding of the structure, the machine component is not necessarily shown to scale. list of reference numbers

Machine component Component body Circumferential direction of groove

surface

longitudinal central axis

director

face

face

conductor end

end area

insulating element

surface

location

Claims

P atentClaims 1. Machine component (1) for an electrical machine comprising a component body (2) in which grooves (4) are formed, wherein electrical conductors (7) are arranged in the grooves (4) and are attached to the axial ends of the grooves ( 4) from which grooves (4) protrude and are arranged crossing one another in at least one protruding area, and wherein the electrical conductors (7) are electrically insulated from one another in the area outside the grooves with additional insulating elements (12), characterized in that the additional insulating elements (12) are arranged exclusively between the electrical conductors (7). 2. Machine component (1) according to claim 1, characterized in that the additional union insulating elements (12) are strip-shaped. 3. Machine component (1) according to claim 1 or 2, characterized in that the additional insulating elements (12) are arranged on surfaces of electrical conductors (7) adhering to. 4. Machine component (1) according to any one of claims 1 to 3, characterized in that the number of additional insulating elements (12) corresponds to a maximum of half the number of electrical conductors (7). 5. Machine component (1) according to one of claims 1 to 4, characterized in that the additional insulating elements (12) have a layer thickness of at most 400 μm. 6. Machine component (1) according to any one of claims 1 to 5, characterized in that the electrical conductors (7) are designed as Lorm bars with an at least approximately quadrangular cross-section. 7. Machine component (1) according to any one of claims 1 to 6, characterized in that between each two electrical conductors (7) only one additional insulating element (12) is arranged. 8. Machine component (1) according to one of Claims 1 to 7, characterized in that the additional insulating elements (12) are arranged between electrical conductors (7) lying one above the other and/or next to one another. 9. Electrical machine comprising a stator and a rotor, characterized in that the stator and / or the rotor as a machine component (1) is formed according to any one of claims 1 to 8. 10. A method for producing a machine component (1) for an electrical machine by providing a component body (2) in which grooves (4) are formed, with electrical conductors (7) being arranged in the grooves (4) in such a way that they protrude from the grooves (4) at the axial ends of the grooves (4) and are arranged crossing one another in at least one protruding area, and the electrical conductors (7) in the area outside the grooves (4) are provided with additional insulating elements (12 ) are electrically insulated from one another, characterized in that the additional insulating elements (12) are arranged exclusively between the electrical conductors (7).