CN112701829A

CN112701829A - Insulator for a stator with increased stiffness

Info

Publication number: CN112701829A
Application number: CN202011122771.XA
Authority: CN
Inventors: M.莱伯尔; D.舒尔兹
Original assignee: Volkswagen AG
Current assignee: Volkswagen AG
Priority date: 2019-10-23
Filing date: 2020-10-20
Publication date: 2021-04-23
Anticipated expiration: 2040-10-20
Also published as: DE102019216281A1

Abstract

In order to provide an insulator (10) of a stator (100), in particular an insulator of an assembled stator, which is arranged between a contact bridge (20) and an end surface (31) of a stator installation space (30), wherein the insulator (10) consists of a single component having a sufficiently high rigidity, the invention proposes that the surface (11) of the insulator (10) is designed such that a resin can be applied to the surface (11) in order to increase the rigidity of the insulator (10), wherein the insulator (10) consists of only one component.

Description

Insulator for a stator with increased stiffness

Technical Field

The invention relates to an insulator of a stator, in particular for assembling a stator, which is arranged between a contact bridge and an end surface of a stator construction space.

Background

Insulators are used in electrical machines and stators thereof to prevent contact between conductive materials at undesired locations. The stator of an electrical machine usually comprises a plurality of coils, wherein the coils are connected to the surrounding electrically conductive lines in the axial end regions of the stator by means of solder and contact strips. The electrical lines, usually three in number, are mounted insulated from one another and can each be surrounded by a busbar, as described, for example, in DE 112011100325T 5. The bus bars insulate the respective wires enclosed therein. The three busbars and the electrical lines described there are arranged one above the other in the axial direction, wherein the busbars can be sealed and insulated by a resin layer with respect to the contact strips arranged underneath.

However, it is also possible to use connectors on the axial ends of the stator for connecting and closing the end sections of the stator wires, as described in DE 102015221843 a 1. The connecting element can be a printed circuit board, in particular, wherein the printed circuit board can also have an insulating coating at the upper and/or lower end of the surface. It is also possible to perform an additional sealing with a resin, for example a potting material, so that the stator wires are not exposed and are therefore exposed to the surroundings of the electrical machine.

In the switching ring described in patent document DE 102014012824 a1, insulation of the different layers is also required. The insulating layers can be made of plastic or insulating paper, which serves to seal the electrical connections between the insulating layers with resin or potting material at the ends.

However, the insulation possibilities described here generally consist of a multi-part insulation body which serves to fix, stabilize, increase the rigidity or simply serve only to insulate electrically conductive parts, as required. Insulating paper is often used in order to absorb additional applied insulating resin for improving the rigidity of the insulator. Furthermore, in a multi-piece insulator, assembly is more complicated. In particular for stator assemblies which require insulation between the stator installation space and the conductive contact bridges, both insulation and a certain stability are required, and in the best case, a simple connection or application of resin is also required to seal the small gaps and pores of the solder bars leading to the contact bridges.

Disclosure of Invention

The invention aims to improve rigidity and simplify the assembly of an insulator of a stator of an electrical machine.

This problem is solved by: one of the surfaces of the insulator is designed to enable the application of resin on the surface of said insulator in order to increase the rigidity of the insulator, wherein the insulator consists of only a single component for the sake of simplicity of assembly.

In the present invention, the stator structural space represents a portion of the stator in which a coil, for example, an induction coil, is placed together with a core of the coil. The stator can be used in particular for an electrical machine having a rotor which runs internally, wherein the shape of the stator is preferably substantially identical to the shape of a hollow cylinder. The stator is preferably bounded in the axial direction upwards or downwards by an end surface, wherein the end surface is preferably of annular design. The stator is preferably an assembled stator, i.e. consisting of a plurality of single parts.

On the end surface of the stator, elements for electrically connecting the stator coils to the electrically conductive lines are preferably arranged. According to the invention, an insulating body is arranged on the end surface and a contact bridge is arranged thereon, wherein preferably a plurality of electrically conductive lines are arranged via the contact bridge. In order to electrically connect the stator to the contact bridges and the electrical lines, a plurality of solder strips are preferably arranged perpendicular to the end surfaces on said end surfaces. The welding bead is preferably arranged or placed on the inner and/or outer circumference of the, in particular, annular end surface. The insulation, the contact bridge and the electric line preferably arranged thereon are therefore particularly preferably arranged between the solder strips arranged on the inner and outer circumferential portions of the end surface. The insulating body is preferably designed curved, in particular so that the average radius of curvature of the long sides is substantially equal to the average radius given by the inner and outer circumferential portions of the end surface. The insulator preferably insulates the contact bridge spatially relative to the stator structure. The wires and contact bridges may be made of copper or coated with copper, and the insulation is preferably made of plastic.

The insulation body according to the invention consists of only a single component, i.e. in particular not of the insulating strip and the insulating paper. The assembly of the stator is thereby significantly simplified, since only one component has to be joined and assembled. In the embodiments known from the prior art, the insulating paper needs to absorb the applied resin and increase the stiffness of the insulation after the resin has cured. In order to ensure an increased stiffness without the use of insulating paper, the insulator according to the invention has a surface which is designed such that the resin can be applied better on said surface. To this end, the surface may be bonded to the resin or shaped to facilitate placement of the resin on the surface. It is important in particular here that the resin remains in the uncured state on the surface for a certain period of time and can therefore be cured. According to the invention, one of the surfaces of the insulator is designed such that resin can be applied on said surface, in particular forming a part of the surface, to improve the application of resin, wherein the resin application is improved compared to a flat surface. The surface of the insulator described below is a surface designed for application of resin.

The possibility of a better arrangement of the resin on one of the surfaces of the insulator is therefore also necessary, since the resin serves to improve the thermal connection of the solder strip to the contact bridge arranged above the insulator. The resin also encloses the small air chambers of the solder bars so that they do not interfere with the electrical conductivity to the contact bridges and the conductive wires. It is therefore advantageous: the resin can be arranged between the insulator and the contact bridge well and in sufficient quantities, i.e. the surface of the insulator is designed to ensure a good arrangement of the resin. The resin may be introduced between the insulator and the contact bridge in a liquid or flowable state and then cured.

The surface of the insulating body facing the contact bridge is preferably designed such that, in the assembled state of the stator, a region of the surface comes into contact with the contact bridge. The surface of the insulator here particularly preferably has elevations and/or depressions. The contact bridges are preferably contacted here by the uppermost regions of the projections. The resin layer arranged on the surface is therefore preferably designed to be of different thicknesses, since in the region of the depressions of the surface the resin layer can be considerably thicker than in the region of the elevations.

The elevations and depressions can be arranged in a pattern here, for example in the form of a honeycomb, a ring, a corrugation, a groove or a pyramid. The surface of the insulator particularly preferably has a groove running through said surface in the longitudinal direction. If the insulator is bent along its long sides, the convex portions and the concave portions also extend in a bent manner. Here, the radius of curvature of the convex portion and the concave portion is larger than the smaller of the two radii of curvature of one of the long sides of the insulator and smaller than the larger of the two long sides. The elevations and depressions preferably extend alternately with one another in the radial direction of the curvature, wherein grooves can thus be formed. This is advantageous in particular because the resin can flow along the bend from one side of the insulator onto the other side via the groove and can therefore fill the intermediate space between the insulator and the contact bridge in the assembled state without complications.

The elevations and depressions of the surface of the insulator do not exceed in particular a height or depth of 1 mm. The height and depth are calculated from the highest point of the raised portion or the deepest point of the recessed portion to the surface of the insulator. The projections or depressions of the surface of the insulator are particularly preferably less than 0.7mm high or deep. In the case of too great a height and/or depth, there is the risk that the resin does not fill the intermediate space between the contact bridge and the insulating body before curing, but flows out on the side of the insulating body and leaves the intermediate space open to the contact bridge. In the case of using a more viscous resin, the height of the convex portion or the depth of the concave portion may also take a value of at most 5 mm.

The length of the insulating body is particularly preferably such that it is equivalent to at least half, in particular one quarter to one third, of the circumference of the end surface of the stator installation space, i.e. the outer edge. In the case of a ring-shaped end surface, the length of the insulator is preferably equivalent to the arc of the circumference of the end surface of the circular segment of maximum 180 °. The length of the insulator is especially equivalent to the circular arc of the outer peripheral portion of the annular end surface of the circular arc segment of 60 ° to 120 °. The insulation and the contact bridges are preferably arranged on the end surface of the stator construction space in such a way that they do not cover the entire ring of the end surface, but only in an area covering less than one half, preferably approximately one third, of the end surface.

The stator for an electrical machine according to the invention comprises a contact bridge, an insulator as described above and a stator construction space comprising at least one solder bar for the contact bridge, wherein the insulator is arranged between an end surface of the stator construction space and the contact bridge. The stator is preferably an assembled stator, wherein the rotor rotates inside the stator. The stator is preferably in the shape of a hollow cylinder. The insulation of the stator particularly preferably does not comprise insulation paper, particularly preferably no insulation paper is introduced in the entire stator. The stator is particularly preferably provided with a star connection.

The invention also comprises an electrical machine with a stator as described above, wherein the electrical machine preferably has a star connection.

Drawings

The invention is exemplarily described below with reference to preferred embodiments.

In the figures there is shown schematically a view of,

fig. 1 shows an exploded view of a known embodiment of an end section of a stator structure space;

fig. 2 shows an exploded view of an embodiment according to the invention of an end section of a stator structural space; and

fig. 3 shows an enlarged view of the insulator according to the invention, in particular of a part Z of the surface of the insulator.

Detailed Description

Fig. 1 shows a stator 100 in an embodiment known from the prior art. Shown is a part of the end section of the stator construction space 30 with an end surface 31. The end surface 31 of the stator construction space 30 is annular in shape, since the center of the stator construction space 30 has a cavity in which the rotor can be placed. The welding bars 33 are disposed perpendicularly projecting from the end surface 31, the welding bars 33 being arranged opposite to each other on the inner and outer peripheral portions.

An insulator 10 is arranged on the end surface 31 in the assembled state of the stator 100, wherein the insulator 10 rests in the region of the end surface 31 formed between the welding strips 33 on the inner and outer circumference. The insulating body 10 is composed here in the known embodiment shown of an insulating strip 10a and an insulating paper 10 b. The insulating strip 10a has a substantially smooth surface 11 on the side remote from the end surface 31. In the assembled state of the stator 100, the insulating paper 10b is arranged on the surface 11, on which insulating paper 10b the contact bridges 20 are arranged. The contact bridge 20 is designed such that it is connected to a plurality of solder strips 33. In the assembled state, resin is injected between the contact bridge 20 and the end surface 31 of the stator structural space 30, which resin is absorbed by the insulating paper 10b before curing. This increases the stability of the insulating body 10 and improves the conductivity of the solder bars 33 and their connection to the mostly copper contact bridges 20.

Fig. 2 likewise shows a part of a stator structure 30, the end section of which stator structure 30 has an annular end surface 31, which end surface 31 is delimited outward by an outer edge 32 and from which a plurality of welding bars 33 project perpendicularly. The stator installation space 30 is designed in the shape of a hollow cylinder, wherein the rotor can be arranged centrally. The welding strips 33 are arranged such that half are arranged in the region of the inner peripheral portion of the end surface 31 and the other half are arranged in the region of the outer peripheral portion opposite thereto. Fig. 2 shows by way of example 24 welding bars 33, 12 of which are arranged in the region of the inner circumference of the

end surface

31 and 12 in the region of the outer circumference of the end surface 31. Only a segment of the annular shape of the end surface 31 is designed with a welding bead 33, wherein the circular segment is substantially 60 ° in size.

In the circular section of this end surface 31, an insulator 10 is arranged between the welding bars 33 in the assembled state of the stator 100, which insulator rests against the end surface 31, but may also project beyond the end surface 31 and may be in contact with the inner and outer side walls of the stator structure space 30. The insulator 10 is here bent on its long sides such that the curvature of said insulator 10 is of a magnitude between the curvature of the inner and outer peripheral portions of the end surface 31. The surface 11 of the insulator 10 remote from the end surface 31 is in some places in the assembled state of the stator 100 in direct contact with the contact bridges 20 arranged above said surface 11. The surface 11 has protrusions 12 and recesses 13, wherein the contact with the contact bridge 20 takes place at the highest point of the protrusions 12. As is shown in fig. 2, the projections 12 and the recesses 13 can form grooves on the surface 11, wherein the grooves shown in the exemplary embodiment extend in the longitudinal direction and run parallel to the edges of the end surface 31.

The contact bridges 20 are preferably made of an electrically conductive metal, particularly preferably copper, and are electrically connected to a part of the solder bars 33 in the assembled state of the stator 100. Since the surface 11 of the insulator 10 has elevations 12 and depressions 13, resin can flow between the insulator 10 and the contact bridge 20, which resin can subsequently be cured and thus increase the rigidity of the insulator 10. Therefore, the insulating paper 10b as shown in fig. 1 is not required in such an embodiment according to the present invention.

Fig. 3 shows a detail of the insulating body 10, which is denoted by Z in fig. 2, which detail shows the elevations 12 and depressions 13 of the surface 11. The height 14a of the raised portion 12 and the depth 14b of the recessed portion 13 are measured from the surface 11 of the insulator 10, wherein the height 14a and the depth 14b are less than 1mm, preferably less than 0.7 mm. At the highest point of the projection 12, a contact bridge 20 (see fig. 2) rests (rests) in the assembled state of the stator 100. The insulator 10 is made of an electrically insulating material, preferably plastic.

List of reference numerals

100 stator

10 insulator

10a insulating strip

10b insulating paper

11 surface of

12 raised part

13 recessed part

Height of 14a

14b depth

20 contact bridge

30 stator structure space

31 end surface

32 outer edge

33 welding strip

Claims

1. An insulator (10) of a stator (100), in particular an insulator of an assembled stator, which is arranged between a contact bridge (20) and an end surface (31) of a stator construction space (30),

it is characterized in that the preparation method is characterized in that,

one of the surfaces (11) of the insulating body (10) is designed such that a resin can be applied to said surface in order to increase the rigidity of the insulating body (10), wherein the insulating body (10) consists of only one component.

2. Insulator (10) according to claim 1,

it is characterized in that the preparation method is characterized in that,

a plurality of regions of the surface (11) of the insulating body (10) are in contact with the contact bridges (20) in the assembled state of the stator (100).

3. Insulator (10) according to claim 1 or 2,

it is characterized in that the preparation method is characterized in that,

the surface (11) of the insulator (10) has projections (12) and/or recesses (13).

4. Insulator (10) according to claim 3,

it is characterized in that the preparation method is characterized in that,

the elevations (12) and/or depressions (13) of the surface (11) of the insulator (10) form grooves, wherein the grooves extend in a longitudinal direction, which is parallel to an outer edge (32) of an end surface (31) of the stator (100).

5. Insulator (10) according to claim 3 or 4,

it is characterized in that the preparation method is characterized in that,

the elevation (12) of the surface (11) of the insulating body (10) does not exceed a height (14) of less than 1mm, in particular less than 0.7mm, measured from the plane of the surface (11) of the insulating body (10) to the highest point of the elevation (12).

6. Insulator (10) according to one of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the length of the insulating body (10) is equal to at least half, in particular one quarter to one third, of the length of an outer edge (32) of an end surface (31) of the stator installation space (30).

7. Insulator (10) according to one of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the insulator (10) is designed for star connection.

8. Stator (100) for an electrical machine, comprising contact bridges (20), an insulator (10) according to one of the preceding claims and a stator structural space (30), the stator structural space (30) comprising at least one welding bar (33) for the contact bridges (20),

wherein the insulator (10) is arranged between an end surface (31) of the stator structure space (30) and the contact bridge (20).

9. The stator (100) of claim 8,

it is characterized in that the preparation method is characterized in that,

the insulator (10) of the stator (100) and in particular the stator (100) do not comprise an insulating paper (10 b).

10. The stator (100) of claim 8 or 9,

it is characterized in that the preparation method is characterized in that,

the stator (100) has a star connection.

11. An electrical machine having a stator (100) according to any of claims 8 to 10.