DE102017206219A1 - Stator for an electric machine and method for manufacturing a stator of an electric machine - Google Patents

Abstract

A stator (10) for an electrical machine is proposed, comprising conductor elements (20, 21) inserted into the stator (10), wherein ends (48) of the conductor elements (20, 21) protruding from the stator (10) are partially, in particular in pairs are welded together, characterized by a bridge means (60) for increasing a thickness of an electrical insulation material (50) at the ends (48) of the conductor elements (20, 21), wherein the bridge means (60) at end faces of the ends (48) of Conductor elements (20, 21) spaced apart by a predetermined distance from the respective ends (48) of the conductor elements (20, 21), the gap between the ends (48) of the conductor elements (20, 21) and the bridge means (60) is adapted to be bridged by the insulating material (50), wherein the bridging means (60) comprises a part of the conductor element (20, 21) or a separate element.

Description

Field of the invention

The invention relates to a stator for an electrical machine and to a method for producing a stator of an electrical machine.

State of the art

In stators for electrical machines in plug-in technology, the inserted and covered with an electrically insulating paint conductor elements must be connected together to produce the overall winding. The conductor elements are hereby usually partly, in particular in pairs, welded together, e.g. by laser welding. For welding, the ends of the conductor elements usually have to be freed of the varnish, so that during welding no inclusions are formed in the weld due to outgassing of the varnish. After welding, the welded together ends of the conductor elements are thus free of paint.

Particularly in the automotive sector, high demands are placed on the power density of the electrical machine or the stator. Therefore, to ensure the insulation strength or dielectric strength, an insulating material must be applied to the lacquer-free ends of the conductor elements. This is especially true when the electric machine is to be operated with the stator in an oil environment. The problem with the application of insulation material to the lacquer-free ends of the conductor elements after welding is that they often have sharp-edged areas. When applying the insulating material in the region of the ends of the conductor elements or the sharp edges, a high capillary pressure acts locally on the liquid / liquefied insulating material, which "pushes" the insulation material away from the edges. This leads to a smaller thickness of the insulating material in the region of the edges or the ends of the conductor elements. Thus, the insulating material often has a thinner compared to the other areas of the conductor element thickness. With a smaller thickness of the insulating material, the insulation strength of the conductor element decreases. Increasing the thickness of the insulating material over the entire area of the ends of the conductor elements which is freed of lacquer, in order to achieve a predetermined dielectric strength or dielectric strength also in the region of the edges or ends of the conductor element, leads to an increased use of insulating material and thus to an increased level Costs.

Disclosure of the invention

Advantages of the invention

Embodiments of the present invention can advantageously make it possible to provide a stator in which insulating material is uniformly present on ends of the conductor elements, or to apply insulating material uniformly to ends of the conductor elements.

According to a first aspect of the invention, a stator for an electrical machine is proposed comprising conductor elements inserted into the stator, wherein ends of the conductor elements protruding from the stator are partially, in particular in pairs, welded together, characterized by a bridge means for increasing a thickness of an electrical insulation material the ends of the conductor members, the bridging means being disposed at end faces of the ends of the conductor members spaced apart a predetermined distance from the respective ends of the conductor members, the gap between the ends of the conductor members and the bridging means being bridged by the insulating material to be, wherein the bridging means comprises a part of the conductor element or a separate element.

One advantage of this is that, as a rule, the insulating material is arranged uniformly or with substantially the same thickness on the ends of the conductor elements. This also typically applies if the edges of the ends of the conductor elements have low radii or are sharp-edged. As a result, material is generally saved. This usually reduces costs. In addition, the stator is typically designed to save space and space. The stator can also be operated in an oil environment usually.

According to a second aspect of the invention, a method is proposed for producing a stator of an electrical machine, the method comprising the following steps: providing non-interconnected conductor elements inserted in the stator, wherein ends of the conductor elements protruding from the stator are painted with a lacquer ; Removing the paint from each at least a portion of the projecting from the stator ends of the conductor elements; Welding, in particular laser welding, of the parts freed of the paint from in each case two or more directly mutually adjacent conductor elements for the electrical connection of the two or more directly mutually adjacent conductor elements; Applying a liquid / liquefied insulating material for electrical insulation on the previously freed from lacquer ends of the conductor elements while each bridge means in one such distance to the welded together ends of the conductor elements is that the liquid / liquefied insulating material forms a connection between the respective welded ends of the conductor elements and the bridge means; and curing the insulation material.

The advantage of this is that the insulating material is typically applied evenly or with substantially the same thickness to the ends of the conductor elements. This usually takes place even when the ends of the conductor elements have sharp edges or edges with small radii. In addition, by this method usually a stator can be produced, which requires very little insulation material with high insulation strength and dielectric strength.

The insulating material encloses respective ends of the conductor elements, wherein the ends enclosed by the respective insulation material are welded together. In each case welded together in pairs ends of conductor elements, the insulating material thus encloses a respective pair of welded together ends of conductor elements.

Ideas for embodiments of the present invention may be considered, inter alia, as being based on the thoughts and findings described below.

According to one embodiment, the gap is equal to or less than one half of a diameter of the respective end of the conductor element. As a result, the insulating material is arranged evenly more uniformly on the ends of the conductor elements in the rule. In addition, this typically typically ensures that the insulation material bridges the gap.

According to one embodiment, the bridging means is part of a ring, which is arranged in the axial direction of the stator above the respective ends of the conductor elements. As a result, the bridging means can generally be embodied in a technically particularly simple and cost-effective manner. This usually reduces the manufacturing cost of the stator.

According to one embodiment, the insulating material of the respective welded ends of the conductor elements at a distance from the insulating material of the immediately adjacent welded together ends of the conductor elements. One advantage of this is that typically there are no insulating material bridges between the insulating materials of immediately adjacent ends of the conductor elements. By insulating material bridges, the electrical insulation between non-welded ends of conductor elements could be lowered. Thus, typically, the lack of insulation material bridges between insulating materials of immediately adjacent ends of the conductor elements increases the insulation strength of the stator.

According to one embodiment, the ends of the conductor elements each have one or more sharp edges. One advantage of this is that the stator, in particular the conductor elements, is usually technically particularly easy to produce. This typically further reduces manufacturing costs.

According to one embodiment, the bridge means is in an imaginary direct extension of the ends of the conductor elements. The advantage of this is that the bridge of insulating material, which bridges the gap, typically consists of very little material or requires very little material. This generally reduces costs further.

According to one embodiment, the side of the additional element or of the additional elements facing the ends of the conductor elements has a surface which attracts the liquid insulating material. As a result, the formation of the bridge or bridges of insulating material over the gap is usually technically simplified. In addition, as a result, the insulating material bridge typically requires very little material.

According to one embodiment of the method, the insulation material is applied such that the insulation material of the respective welded ends of the conductor elements after applying and curing of the insulating material further comprises a distance to the insulating material of the immediately adjacent welded together ends of the conductor elements. As a result, the formation of insulating material bridges between the insulating materials of immediately adjacent ends of the conductor elements is usually prevented. By insulating material bridges, the electrical insulation between non-welded ends of conductor elements could be lowered. Thus, in general, by preventing insulating material bridges between insulating materials from immediately adjacent ends of the conductor members, the insulation strength of the manufactured stator increases.

According to one embodiment of the method, the bridge means is at a distance to the welded together ends of the conductor elements during the application of the liquid / liquefied insulating material, the same or less than a half of a diameter of the respective end of the conductor element. As a result, the insulating material is applied even more uniformly on the ends of the conductor elements usually. In addition, this typically typically ensures that the insulation material bridges the gap.

It should be understood that some of the possible features and advantages of the invention are described herein with respect to different embodiments of the stator. A person skilled in the art will recognize that the features can be suitably combined, adapted or replaced in order to arrive at further embodiments of the invention.

list of figures

• 1 zeigt eine perspektivische Ansicht einer Ausführungsform des Stators;
• 2 zeigt eine detaillierte perspektivische Ansicht eines Bereichs des Stators aus 1;
• 3 zeigt eine schematische Querschnittsansicht eines Paars von Enden von Leiterelementen mit Brückenmittel; und
• 4 zeigt eine weitere schematische Querschnittsansicht eines Paars von Enden von Leiterelementen mit Brückenmittel.

Embodiments of the invention will now be described with reference to the accompanying drawings, in which neither the drawings nor the description are to be construed as limiting the invention.

• 1 shows a perspective view of an embodiment of the stator;
• 2 shows a detailed perspective view of a portion of the stator 1 ;
• 3 shows a schematic cross-sectional view of a pair of ends of conductor elements with bridge means; and
• 4 shows another schematic cross-sectional view of a pair of ends of conductor elements with bridge means.

The figures are only schematic and not to scale. Like reference numerals designate the same or equivalent features in the figures.

Embodiments of the invention

1 shows a perspective view of an embodiment of the stator 10 , 2 shows a detailed perspective view of a portion of the stator 10 out 1 ,

The stator 10 is designed for an electrical machine. The stator 10 is especially designed for a vehicle. The stator 10 is designed in plug-in technology. The electrical conductor elements 20 . 21 are in the stator 10 plugged in. end up 48 the electrical conductor elements 20 . 21 stand out of the stator 10 upwards. The electrical conductors are equally spaced from each other along the circumference of the stator 10 arranged. On the bottom are also ends 48 the conductor elements 20 . 21 from the stator 10 out. This is not shown in the drawings.

wobei

• σ die Oberflächenspannung des flüssigen Isolationsmaterials 50, und
• r der Kantenradius ist. Somit steigt der Kapillardruck für kleiner werdende Kantenradien stark an.

The ladder elements 20 . 21 show at their ends 48 sharp edges 70 . 75 on. These are due to the separation process (eg shearing of the conductor element 20 . 21 ) emerged. The edges 70 . 75 thus have small edge radii. The capillary pressure on a liquid or liquefied insulation material 50 in the edge area is calculated as follows: $${\text{p}}_{\mathrm{\sigma }}=\left(2*\mathrm{\sigma }\right)/\text{r}$$

in which

• σ the surface tension of the liquid insulation material 50 , and
• r is the edge radius. Thus, the capillary pressure increases sharply for decreasing edge radii.

The electrical conductors are covered with a lacquer for electrically insulating the conductor elements 20 . 21 Mistake. The paint is not shown in the drawings.

The ends 48 the conductor elements 20 . 21 or areas thereof are freed from the paint. The ends 48 the conductor elements 20 . 21 include at least the end edges 70 . 75 of the respective conductor element 20 . 21 and a portion of the conductor element 20 . 21 immediately adjacent to the end edges 70 . 75 , The ends 48 the conductor elements 20 . 21 can, but do not have, get the complete out of the stator 10 outstanding part of the ladder elements 20 . 21 each include.

The ends 48 the conductor elements 20 . 21 are welded together in pairs. It is also conceivable that three or more than three ends 48 of ladder elements 20 . 21 each welded together. It is also made of pairs welded together 40 - 45 of ends 48 of ladder elements 20 . 21 spoken. However, this term also means more than two ends 48 of ladder elements 20 . 21 , eg three or four ends of ladder elements 20 . 21 which are welded together includes.

The welding may in particular include or be a laser welding.

After welding are the ends 48 the conductor elements 20 . 21 furthermore without lacquer or without electrical insulation.

It becomes a liquid or liquefied insulation material 50 for electrically insulating the ends welded together 48 of the conductor elements 20 . 21 or the pairs welded together 40 - 45 of ends 48 the conductor elements 20 . 21 towards the environment on the ends 48 the conductor elements 20 . 21 applied. The insulation material 50 in particular so on the ends 48 the conductor elements 20 . 21 applied, that all previously freed from paint areas of the conductor elements 20 . 21 or the ends 48 the conductor elements 20 . 21 with insulation material 50 be provided so that the respective entire conductor element 20 . 21 is electrically isolated from the environment. The insulation material 50 thus encloses each ends 48 of ladder elements 20 . 21 that are welded together.

During the application of the insulation material 50 is or becomes a bridging means 60 near the ends 48 the conductor elements 20 . 21 arranged. Between the ends 48 or end edges 70 . 75 the respective conductor elements 20 . 21 or the couple 40 - 45 of ends 48 the conductor elements 20 . 21 and the bridging means 60 is a gap or a distance arranged. The gap may be equal to or less than one half of a diameter of the respective end 48 of the conductor element 20 . 21 be.

The gap or distance is selected such that during application of the insulating material 50 the liquid or liquefied insulation material 50 a bridge between each end 48 of the conductor element 20 . 21 and the bridging means 60 forms. The bridging means 60 may for example comprise a ring or be a ring. The ring may be formed of a plastic. The ring may in particular be made of a low-cost material. The material of the bridge means 60 is electrically non-conductive.

Due to the surface tension of the insulation material 50 Thus, the gap or distance between the pairs 40 - 45 of ends 48 the conductor elements 20 . 21 and the bridging means 60 bridged.

Instead of a ring are also several individual bridging means 60 conceivable, each spaced from the ends 48 the conductor elements 20 . 21 are arranged.

The insulation material 50 forms a bridge between the respective ends 48 the conductor elements 20 . 21 or the respective pairs 40 - 45 of ends 48 the conductor elements 20 . 21 and the bridging means 60 , This results in a uniform or uniform thickness of the applied insulation material 50 in the areas of the conductor elements 20 . 21 that from the ends 48 or end edges 70 . 75 are spaced, and in the end regions or at the ends 48 / end edges 70, 75 of the conductor elements 20 . 21 reached. The capillary pressure of the liquid or liquid insulation material 50 at the ends 48 the conductor elements 20 . 21 is thus similar or equal to the capillary pressure of the liquid insulation material 50 which is spaced from the ends 48 the conductor elements 20 . 21 or the end edges 70 . 75 the ends 48 the conductor elements 20 . 21 is.

After application of the insulation material 50 becomes the insulation material 50 hardened. This can be done for example by light and / or heat.

The bridging means 60 usually remains on the stator 10 ,

In 2 is the insulation material 50 around some of the couples 40 - 45 of welded ends 48 the conductor elements 20 . 21 shown cut (in particular the second, third and fourth pair 40 - 45 of ends 48 the conductor elements 20 . 21 from the left in 2 ).

The insulation material 50 , each a first pair 40 of ends 48 the ladder elements 20 . 21 encloses, is spaced from the insulating material 50 formed, one directly to the first pair 40 of ends 48 the ladder elements 20 . 21 adjacent second pair 41 of ends 48 the conductor elements 20 . 21 encloses. Thus, there are no direct or immediate bridges between the respective insulation materials 50 , The insulation materials 50 are in 1 and 2 but over the ring or bridge means 60 indirectly connected.

The ring may have grooves. The ends 48 the ladder elements 20 . 21 are partially disposed in the grooves but spaced from the ring. The insulation material 50 closes this distance between the ends 48 the conductor elements 20 . 21 and the ring.

By the absence of bridges between the insulating materials 50 of the respective pairs 40 - 45 of ends 48 the conductor elements 20 . 21 becomes the insulation strength or dielectric strength of the stator 10 increased because no electric current can flow through such bridges.

In the drawings, this is bridging means 60 one to the stator 10 with ladder elements 20 . 21 additional element. However, it is also conceivable that the bridge means 60 a part or an area of the conductor element 20 . 21 or another part of the stator 10 is. Again, the gap or distance by means of the insulating material 50 bridged. The ends 48 of the conductor element 20 . 21 can be bent accordingly, so that in the imaginary extension of the ends 48 of the conductor element 20 . 21 a part or area of the conductor element 20 . 21 located.

Electrical connection elements or conductor elements 20 . 21 for electrically connecting the stator 10 are in 1 or in 2 not shown.

3 shows a schematic cross-sectional view of a pair 40 - 45 of ends 48 of ladder elements 20 . 21 with bridge means 60 , 4 shows another schematic cross-sectional view of a pair 40 - 45 of ends 48 of ladder elements 20 . 21 with bridge means 60 ,

In 3 respectively. 4 is clearly visible, as by the presence of a bridge means 60 a gap between the end edges 70 . 75 the ends 48 the conductor elements 20 . 21 and the bridging means 60 is overcome. In addition, it can be clearly seen that the thickness of the insulating material 50 at the ends 48 the conductor elements 20 . 21 and at the other areas of the conductor element freed of paint 20 . 21 is similar or substantially the same.

In 3 is an additional element as bridge means 60 available. In 4 is the conductor element 20 . 21 or a part thereof itself the bridging means 60 , This is the end 48 of the conductor element 20 . 21 or the ends 48 the conductor elements 20 . 21 bent accordingly, so that in the direct imaginary extension of the ends 48 the conductor elements 20 . 21 a part of the respective conductor element 20 . 21 itself is present.

The ring or the bridging means can also act as spacers to a cover of the stator or the electric machine.

Finally, it should be noted that terms such as "comprising," "comprising," etc., do not exclude other elements or steps, and terms such as "a" or "an" do not exclude a multitude. Reference signs in the claims are not to be considered as limiting.

Claims (10)

Stator (10) for an electrical machine comprising in the stator (10) inserted conductor elements (20, 21), wherein from the stator (10) protruding ends (48) of the conductor elements (20, 21) partially, in particular in pairs, are welded together characterized by bridging means (60) for increasing a thickness of an electrical insulation material (50) at the ends (48) of the conductor elements (20, 21), the bridging means (60) being provided at end faces of the ends (48) of the conductor elements (20, 21). 21) is spaced from the respective ends (48) of the conductor elements (20, 21) by a gap at a predetermined distance, the gap between the ends (48) of the conductor elements (20, 21) and the bridge means (60) therefrom is formed to be bridged by the insulating material (50), wherein the bridging means (60) comprises a part of the conductor element (20, 21) or a separate element. Stator (10) after Claim 1 wherein the gap is equal to or less than one half of a diameter of the respective end (48) of the conductor element (20, 21). Stator (10) after Claim 1 or 2 wherein the bridge means (60) is part of a ring disposed in the axial direction of the stator (10) above the respective ends (48) of the conductor elements (20, 21). Stator (10) according to one of the preceding claims, wherein the insulating material (50) of the respective welded ends (48) of the conductor elements (20, 21) at a distance from the insulating material (50) of the immediately adjacent welded together ends (48) of the conductor elements (20, 21). A stator (10) according to any one of the preceding claims, wherein the ends (48) of the conductor elements (20, 21) each have one or more sharp end edges (70, 75). A stator (10) according to any one of the preceding claims, wherein the bridging means (60) is in an imaginary direct extension of the ends (48) of the conductor members (20, 21). The stator (10) of any one of the preceding claims, wherein the side of the additional element (s) facing the ends (48) of the conductor elements has a surface which is attractive to the liquid insulation material (50). Method for producing a stator (10) of an electrical machine, the method comprising the following steps: providing non-interconnected conductor elements (20, 21) inserted into the stator (10), wherein ends (48, 48) protruding at least from the stator (10) ) of the conductor elements (20, 21) are painted with a lacquer; Removing the paint from at least part of the ends (48) of the conductor elements (20, 21) protruding from the stator (10); Welding, in particular laser welding, the freed from the paint parts of in each case two or more conductor elements (20, 21) which are directly adjacent to one another for the electrical connection of the two or more directly adjacent conductor elements (20, 21); Applying a liquid / liquefied insulating material (50) for electrical insulation on the previously lacquer - free ends (48) of the conductor elements (20, 21) while each bridging means (60) at such a distance to the mutually welded ends (48) of Conductor elements (20, 21) is that the liquid / liquefied insulation material (50) forms a connection between the respective welded-together ends (48) of the conductor elements (20, 21) and the bridge means (60); and curing the insulating material (50). Method according to Claim 8 in that the insulation material (50) is applied in such a way that the insulation material (50) of the respective welded-together ends (48) of the conductor elements (20, 21) remains spaced from the insulation material (50) after the insulation material (50) has been applied and cured ) of the immediately adjacent welded together ends (48) of the conductor elements (20, 21). Method according to Claim 8 or 9 wherein said bridge means (60) is spaced from said welded ends (48) of said conductor members (20, 21) during application of said liquid / liquified insulation material (50) equal to or less than one-half of a diameter of the respective one End (48) of the conductor element (20, 21).

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