Wiring element, stator, rotor, method for producing a stator, method for producing a rotor, and kit of parts

Abstract

The invention relates to a wiring element (1), in particular for electrically contacting two mutually spaced contact elements (2), comprising a first wire end (3) and a second wire end (4). The wiring element (1) has an insulation (5) between the first wire end (3) and the second wire end (4), wherein the insulation (5) is made of a flat insulation element (6) that at least partly surrounds the wiring element (1) and has a first edge (7) extending in the longitudinal extension of the wiring element (1) and a second edge (8) extending in the longitudinal extension of the wiring element (1). The first edge (7) is fixed relative to the second edge (8) of the flat insulation element (6) by means of a bonded connection and / or a form-fitting connection such that the wiring element (1) is surrounded by the flat insulation element (6) in a tubular manner.

Description

[0001] Connection element, stator, rotor, method for producing a stator, method for producing a rotor and kit-of-parts

[0002] The present invention relates to a wiring element, in particular for electrically contacting two spaced-apart contact elements, having a first wire end and a second wire end, wherein the wiring element has insulation between its first wire end and its second wire end. The invention further relates to a stator, a rotor, a method for producing a stator, a method for producing a rotor, and a kit of parts.

[0003] Electric motors are increasingly being used to power motor vehicles, creating alternatives to combustion engines that require fossil fuels. Considerable efforts have already been made to improve the everyday suitability of electric drives and also to provide users with the same level of driving comfort they are accustomed to.

[0004] A detailed description of an electric drive can be found in an article in the magazine ATZ, Volume 63, May 2020, pages 360-365, by Erik Schneider, Frank Fickl, Bernd Cebulski, and Jens Liebold, entitled: "Highly Integrative and Flexible Electric Drive Unit for E-Vehicles." This article describes a drive unit for one axle of a vehicle. This drive unit comprises an electric motor arranged concentrically and coaxially with a bevel gear differential. In the power train between the electric motor and the bevel gear differential, a switchable 2-speed planetary gear set is arranged, which is also positioned coaxially with the electric motor or the bevel gear differential or spur gear differential. The drive unit is very compact and, thanks to the switchable 2-speed planetary gear set, allows a good compromise between gradeability, acceleration, and energy consumption. Such drive units are also referred to as e-axles.

[0005] In addition to purely electric drivetrains, hybrid drivetrains are also known. Such drivetrains in hybrid vehicles typically comprise a combination of an internal combustion engine and an electric motor, enabling purely electric operation—for example, in urban areas—while maintaining sufficient range and availability, especially for long-distance journeys. Furthermore, in certain operating situations, it is possible to use both the internal combustion engine and the electric motor simultaneously.

[0006] In addition to their use in electromobility, electric machines are also used, for example, as electric motors for automation or as industrial motors. Industrial motors, in particular, have a wide variety of types with different production runs and requirements. One approach to managing this diversity is to use common geometries, such as sheet metal sections, to then differentiate the product into types and their properties through the wiring of the individual coils.

[0007] For the development of electrical machines, in particular electrical machines for the above-mentioned hybrid or fully electric motor vehicles or also for wheel hub drives, basically different winding technologies for a stator of an electrical machine are known.

[0008] For electrical insulation in multi-phase windings, both the dielectric strength of the individual coils within a phase and the dielectric strength of the connecting wires between the coils within a phase and between the phases, e.g., in a star-Z-delta configuration, must be ensured. The electrical insulation of the winding heads is typically achieved using so-called phase separators, which are designed as flat insulation material with a defined 2D or 2.5D cut (embossing / curvature). When connecting the windings or the winding ends at one of the winding heads, so-called enclosing insulation elements are used to prevent electrical contact between interconnection elements on or in the winding head of other coils of the same or other phases.

[0009] However, it is often impossible or only possible with considerable effort to automate the process of connecting or insulating the electrical conductors intended for interconnection. An example of this is the comparatively complex automation involved in axially joining hose systems to flexible connecting wires. Alternative insulating bandages are also only partially automatable due to the accessibility of the joining / insulation point.

[0010] It is therefore the object of the present invention to provide a wiring element, in particular for electrically contacting two spaced-apart contact elements, which can be provided with insulation in a simple, automated manner. It is further the object of the invention to realize a stator with an improved wiring element and a rotor with an improved wiring element. It is also the object of the invention to provide an optimized process for producing a stator and for producing a rotor. Finally, it is also an object of the invention to realize a kit of parts for producing insulation for a wiring element for electrically contacting two spaced-apart contact elements.

[0011] This object is achieved by a wiring element, in particular for electrically contacting two contact elements spaced apart from one another, with a first wire end and a second wire end, wherein the wiring element has insulation between its first wire end and its second wire end, wherein the insulation is formed by a surface insulation element which surrounds the wiring element at least in sections and which has a first edge extending in the longitudinal extent of the wiring element and a second edge extending in the longitudinal extent of the wiring element, wherein the first edge is fixed relative to the second edge of the surface insulation element by means of a material connection and / or a form fit, so that the wiring element is enclosed in a tube-like manner by the surface insulation element.

[0012] This offers the advantage that the interconnection element can be manufactured in a highly automated manner. Preferably, a similar or even the same material is used for the surface insulation element as that used for the phase separators of the coils in the winding head. This allows a single material to be used for the winding insulation throughout, saving costs in material supply and logistics as well as in product development and material qualification. Typically, the material thickness is thinner than previously used tubes, which allows for a more compact winding head due to easier routing of the jumper wires and the associated smaller space requirement.

[0013] The layer thicknesses of the surface insulation material can also be flexibly adjusted based on the selected degree of overlap in the outdoor area. Using a surface insulation material also makes it possible to further improve the insulating properties of the material through subsequent secondary insulation, for example, by dripping or dip impregnation. This is typically not possible when using hoses.

[0014] The interconnection element can be formed by a single interconnection wire or a plurality of interconnection wires. It is also conceivable for the interconnection element to consist of a wire bundle in which individual interconnection wires are arranged, for example, in a twisted configuration. In particular, the interconnection element is designed to be flexible. To secure the wires before the actual electrical contact is made, it can be advantageous to fix them with a cable lug. This is typically combined with the cost-effective welding process of thermocompression or resistance welding. The use of contact elements such as cable lugs, welding sleeves, or similar elements is preferred, particularly for a larger number of parallel conductors in a connecting wire.

[0015] The surface insulation element preferably has a film-like shape. For example, a surface insulation element can be designed as insulating paper or an insulating fabric. In principle, it is also possible to form the surface insulation element from an electrically insulating plastic film. A surface insulation element can be provided as a flat and / or planar blank. The surface insulation element preferably has a rectangular shape. In principle, any other surface shapes are also conceivable.

[0016] According to the invention, the first edge is fixed relative to the second edge of the surface insulation element by means of a material connection and / or a form fit. The form fit can be created, for example, by folding the edges. The use of an adhesive is particularly advantageous for a material connection. It is particularly advantageous if at least one of the edges is already provided with an adhesive strip, so that the application of an adhesive during production of the insulation of the interconnection element can be dispensed with. A combination of the methods in a sequence can also bring advantages from a process point of view, e.g. through temporary fixation by means of a form fit, which is subsequently additionally fixed in the process chain by secondary insulation by means of a material connection.

[0017] For form-locking, it may be useful to match the geometries of the edges to each other, thus preventing disassembly of the surface insulation element's edges through self-locking. This principle is based on a receiving contour and a penetrating contour on the opposite side, similar to the key-lock principle. The receiving contour can be designed in various ways, for example, through undercuts in the flank contour, as well as perforations or pockets.

[0018] According to an advantageous embodiment of the invention, it can be provided that the material bond is produced by means of an adhesive which is designed as a strip on the first edge that extends at least partially in the longitudinal extent of the interconnection element and / or the material bond is produced by means of an adhesive which is designed as a strip on the second edge that extends at least partially in the longitudinal extent of the interconnection element. The advantage of this embodiment is that a particularly secure and simple material bond can be realized. The adhesive can be applied in strip form. This can be achieved, for example, by a plurality of adhesive points arranged in strips, a continuous or interrupted adhesive line. The strip can be straight, in a zigzag shape, or even wave-shaped.

[0019] The object of the invention is further achieved by a stator of an electrical machine with a stator winding, wherein at least one interconnection element according to one of claims 1-2 is used for the electrical interconnection of the stator winding. The design of the stator with the interconnection element enables a more compact winding head with reduced material and logistics costs on the product side. On the process side, automation of the interconnection and insulation processes is possible, thereby saving costs in series production. Thus, the customer's product flexibility is maintained, and cost potential can be realized both in product design and in production.

[0020] Furthermore, the object of the invention can also be achieved by a rotor of an electrical machine with a rotor winding, wherein at least one interconnection element according to one of claims 1-2 is used for the electrical interconnection of the rotor winding. The advantageous effect of this embodiment is based on the fact that even for wound rotors, for example, of DC machines, interconnection must be carried out in a confined space. The demonstrated solution is particularly suitable for this purpose due to its good installation properties.

[0021] Furthermore, the object of the invention is also achieved by a method for producing a stator of an electrical machine comprising the following steps:

[0022] • Provision of a stator,

[0023] • Provision of a stator winding,

[0024] • Providing a wiring element for electrically contacting two contact elements of the stator winding that are spaced apart from one another, • Providing a surface insulation element that has a first edge that extends in the longitudinal extent of the wiring element and a second edge that extends in the longitudinal extent of the wiring element, a) establishing electrical contact between the two contact elements of the stator winding that are spaced apart from one another by means of the wiring element, b) inserting the wiring element into the surface insulation element, c) folding over the surface insulation element so that the wiring element is enclosed in a tube-like manner by the surface insulation element, d) fixing the first edge relative to the second edge of the surface insulation element by means of a material connection and / or a form fit.

[0025] This makes it possible to produce insulation of the interconnection wires that is structurally compact but flexible in terms of product properties, which is particularly suitable for automation due to the defined process sequence.

[0026] Furthermore, the object of the invention can also be achieved by a method for producing a rotor of an electrical machine comprising the following steps:

[0027] • Provision of a rotor,

[0028] • Provision of a rotor winding,

[0029] • Provision of a connection element for electrically contacting two spaced-apart contact elements of the rotor winding,

[0030] • Providing a surface insulation element which has a first edge extending in the longitudinal extent of the interconnection element and a second edge extending in the longitudinal extent of the interconnection element, a) establishing electrical contact between the two contact elements of the rotor winding which are spaced apart from one another by means of the interconnection element, b) inserting the interconnection element into the surface insulation element, c) folding over the surface insulation element so that the interconnection element is enclosed in a tube-like manner by the surface insulation element, d) fixing the first edge relative to the second edge of the surface insulation element by means of a material connection and / or a form connection.

[0031] In a likewise preferred embodiment of the invention, it can also be provided that, before the interconnection element is inserted into the surface insulation element, the surface insulation element is preformed into a V- or U-shaped cross-section. This can ensure centering around the center position of the surface insulation element, particularly with large conductor cross-sections or a large number of parallel partial conductors. This simplifies the enclosing step and ensures improved positioning accuracy of the contact elements and improved process capability during assembly.

[0032] It may also be advantageous to further develop the invention in such a way that the pre-forming of the surface insulation element takes place using a molding tool that has a channel open on one side in cross-section, in particular a V- or U-shaped channel, into which the surface insulation element is inserted. The advantage that can be realized in this way is that, depending on the specific contour of the interconnection elements, individual guiding properties of the surface insulation element can be developed in order to enable optimal centering for the given product contour.

[0033] According to a further preferred embodiment of the subject matter of the invention, the surface insulation element can be drawn and / or held into the channel by means of a negative pressure. This can prevent relative movement in the plane of the surface insulation element when the contact element and the surface insulation element are mated.

[0034] Finally, the invention can also be advantageously designed such that the channel has two channel wings that are movable relative to one another.

[0035] Finally, the object of the invention is also achieved by a kit of parts for producing an insulation of a circuit element for electrical

[0036] Contacting two spaced-apart contact elements, comprising:

[0037] • A plurality of interconnection elements each for electrically contacting two contact elements spaced apart from each other, each with a first wire end and a second wire end,

[0038] • A plurality of surface insulation elements, each having a first edge extending in the longitudinal direction of the interconnection element with a first adhesive strip and a second edge extending in the longitudinal direction of the interconnection element,

[0039] • a forming tool which has a channel which is open on one side in cross-section, in particular a V- or U-shaped channel, in which the surface insulation element can be inserted.

[0040] The advantage that results from this is that all elements necessary for assembly, wiring and insulation can be provided in a particularly assembly-friendly and convenient manner.

[0041] The kit of parts can, for example, be a packaging unit. It is also possible to package the kit of parts as a collection of separate

[0042] Storage containers for storing the individual components or the respective component groups of the kit of parts. The invention will be explained in more detail below with reference to figures, without limiting the general inventive concept.

[0043] It shows:

[0044] Figure 1 shows a circuit element in two different manufacturing states, each in a top view,

[0045] Figure 2 shows a detailed view of an interconnection element in a perspective view,

[0046] Figure 3 is a cross-sectional view of the interconnection element,

[0047] Figure 4 shows a wiring element with an adhesive strip applied to the surface insulation element in a plan view

[0048] Figure 5 shows a stator with a connection element in a plan view of the winding head,

[0049] Figure 6 shows a first embodiment of a molding tool for producing an interconnection element in two different manufacturing states of the interconnection element, each in a cross-sectional view,

[0050] Figure 7 shows a second embodiment of a molding tool for producing an interconnection element in two different manufacturing states of the interconnection element, each in a cross-sectional view,

[0051] Figure 8 shows a kit of parts in a schematic block diagram. Figure 1 shows a connection element 1, in particular for electrically contacting two spaced-apart contact elements 2, such as those found particularly at the ends of stator windings or rotor windings in electrical machines.

[0052] The interconnection element 1 has a first wire end 3 and a second wire end 4, wherein the interconnection element 1 has an insulation 5 between its first wire end 3 and its second wire end 4. The insulation 5 is formed by a surface insulation element 6 that surrounds the interconnection element 1 at least in sections and has a first edge 7 extending in the longitudinal extent of the interconnection element 1 and a second edge 8 extending in the longitudinal extent of the interconnection element 1. The first edge 7 is fixed relative to the second edge 8 of the surface insulation element 6 by means of a material connection and / or a form fit, so that the interconnection element 1 is enclosed by the surface insulation element 6 in a tube-like manner, which can be clearly seen from the combination of Figure 1 and Figures 2-3.

[0053] The right-hand image of Figure 1 shows the interconnection element 1 inserted into the surface insulation element 6, which in this example is formed as an interconnection wire with a circular conductor cross-section. The left-hand image of Figure 1 shows the closed, assembled state of the surface insulation element 6, as shown, for example, in Figure 3.

[0054] From Figure 4 it can be seen that the material bond is created by means of an adhesive 9, which is designed as a strip extending at least partially in the longitudinal extent of the interconnection element 1 on the first edge 7 and at least partially extending on the second edge 8. This can be designed, for example, as an adhesive strip on the surface insulation element 6. Figure 5 shows a stator 10 of an electrical machine 11 with a stator winding 12, in which a interconnection element 1, as known from Figures 1-4, is used for the electrical interconnection of the stator winding 12. Even if it is not shown in the figures, it is of course also possible for a rotor of an electrical machine 11 with a rotor winding to use at least one interconnection element 1 for the electrical interconnection of the rotor winding, as can be seen from Figures 1-4.

[0055] A method for producing a stator 10 of an electrical machine 11 is explained in more detail below; it comprises the following steps:

[0056] First, a stator 10 and a stator winding 12 are provided. Furthermore, a connection element 1 is provided for electrically contacting two spaced-apart contact elements 2 of the stator winding 12. A surface insulation element 6 is also provided, which has a first edge 7 extending in the longitudinal direction of the connection element 1 and a second edge 8 extending in the longitudinal direction of the connection element 1.

[0057] Then, electrical contact is established between the two spaced-apart contact elements 2 of the stator winding 12 by means of the interconnection element 1, which in the embodiment shown in Figure 5 is two winding ends of the winding head of a stator winding. Here, an insulating paper with an adhesive strip is provided as the surface insulation element 6, punched and embossed, and then fed to the insulation point on the interconnection element 1, whereby, for example, the wire bundle of the interconnection element 1 only needs to be positioned over the insulating paper.

[0058] In this state, the interconnection element 1 is inserted into the surface insulation element 6 and the surface insulation element 6 is folded over so that the interconnection element 1 is enclosed in a tube-like manner by the surface insulation element 6. Finally, the first edge 7 is fixed relative to the second edge 8 of the surface insulation element 6 by means of a material connection and / or a form fit.

[0059] What can be seen from Figure 6 is that before the interconnection element 1 is inserted into the surface insulation element 6, the surface insulation element 6 is pre-formed into a contour with a V- or U-shaped cross-section. The pre-forming of the surface insulation element 6 takes place by means of a forming tool 13 which has a channel 14 which is open on one side in cross-section, in particular a V- or U-shaped channel 1, into which the surface insulation element 6 is inserted. The surface insulation element 6 can be drawn into the channel 14 and / or held by means of a vacuum, for example. In a further exemplary embodiment of a forming tool 13, which is shown in Figure 7, the channel 14 has two channel wings 15, 16 which are movable relative to one another and which can be pivoted towards one another after the interconnection element 1 has been inserted.

[0060] The surface insulation element 6, embodied, for example, as insulation paper, is thus transformed from a flat shape into a V- or U-shape by means of the forming tool 13, and finally into a closed shape. By enclosing the insulating point of the interconnection element 1, its electrical insulation is thus created. The bond between the insulation paper and the adhesive 9 creates a permanent connection. The thus insulated interconnection element 1 can be installed and, for example, impregnated with resin after the insulation assembly.

[0061] Finally, Figure 8 shows a kit of parts 20 for producing insulation for a wiring element 1 for electrically contacting two spaced-apart contact elements 2. This kit comprises a plurality of wiring elements 1, each for electrically contacting two spaced-apart contact elements 2, each with a first wire end 3 and a second wire end 4, as well as a plurality of surface insulation elements 6, each having a first edge 7 extending in the longitudinal direction of the wiring element 1 with a first adhesive strip 17 and a second edge 8 extending in the longitudinal direction of the wiring element 1. Finally, the kit of parts 20 also contains a molding tool 13, which has a channel 14 open on one side in cross-section, in particular a V- or U-shaped channel 14, into which the surface insulation element 6 can be inserted.With this kit of parts 20, in particular the method described above for producing an insulation of the interconnection element 1 on a stator 10 can be carried out, wherein the kit of parts 20 provides the assembler with the components and tools required for this purpose in a very convenient manner.

[0062] The invention is not limited to the embodiments illustrated in the figures. The above description is therefore not to be considered restrictive, but rather explanatory. The following claims are to be understood in such a way that a stated feature is present in at least one embodiment of the invention. This does not exclude the presence of further features. Where the claims and the above description define 'first' and 'second' features, this designation serves to distinguish between two similar features without establishing a priority.

[0063] List of reference symbols

[0064] 1 interconnection element

[0065] 2 contact elements

[0066] 3 wire ends

[0067] 4 wire ends

[0068] 5 Insulation

[0069] 6 Surface insulation element

[0070] 7 edge

[0071] 8 edge

[0072] 9 Adhesive

[0073] 10 Stator

[0074] 11 electric machine

[0075] 12 Stator winding

[0076] 13 mold tool

[0077] 14 channel

[0078] 15 canal wings

[0079] 16 channel

[0080] 17 adhesive strips

[0081] 20 kit of parts

Claims

Claims Connection element (1), in particular for electrically contacting two contact elements (2) spaced apart from one another, with a first wire end (3) and a second wire end (4), wherein the connection element (1) has an insulation (5) between its first wire end (3) and its second wire end (4), characterized in that the insulation (5) is formed by a surface insulation element (6) which surrounds the connection element (1) at least in sections and which has a first edge (7) extending in the longitudinal extent of the connection element (1) and a second edge (8) extending in the longitudinal extent of the connection element (1), wherein the first edge (7) is fixed relative to the second edge (8) of the surface insulation element (6) by means of a material connection and / or a form connection, so that the connection element (1) is enclosed by the surface insulation element (6) in a tube-like manner.Connection element according to claim 1, characterized in that the material connection is produced by means of an adhesive (9) which is designed as a strip on the first edge (7) which extends at least in sections in the longitudinal extent of the connection element (1) and / or the material connection is produced by means of an adhesive (9) which is designed as a strip on the second edge (8) which extends at least in sections in the longitudinal extent of the connection element (1). Stator (10) of an electrical machine (11) with a stator winding (12), characterized in that at least one connection element (1) according to one of claims 1-2 is used for the electrical connection of the stator winding (12). Rotor of an electrical machine (11) with a rotor winding, characterized in that at least one connection element (1) according to one of claims 1-2 is used for the electrical connection of the rotor winding. Method for producing a stator (10) of an electrical machine (11), comprising the following steps: • Provision of a stator (10), • Provision of a stator winding (12), • Provision of a connection element (1) for electrically contacting two spaced-apart contact elements (2) of the stator winding (12), • Providing a surface insulation element (6) which has a first edge (7) extending in the longitudinal direction of the interconnection element (1) and a second edge (8) extending in the longitudinal direction of the interconnection element (1), a) establishing an electrical contact between the two contact elements (2) of the stator winding (12) which are spaced apart from one another by means of the interconnection element (1), b) inserting the interconnection element (1) into the surface insulation element (6), c) folding over the surface insulation element (6) so that the interconnection element (1) is enclosed in the manner of a tube by the surface insulation element (6), d) Fixing the first edge (7) relative to the second edge (8) of the surface insulation element (6) by means of a material bond and / or a form fit. A method for producing a rotor of an electrical machine (11) comprising the following steps: • Provision of a rotor, • Provision of a rotor winding, • Provision of a connection element (1) for electrically contacting two spaced-apart contact elements (2) of the rotor winding, • Providing a surface insulation element (6) which has a first edge (7) extending in the longitudinal direction of the interconnection element (1) and a second edge (8) extending in the longitudinal direction of the interconnection element (1), a) establishing an electrical contact between the two spaced-apart contact elements (2) of the rotor winding by means of the interconnection element (1), b) inserting the interconnection element (1) into the surface insulation element (6), c) folding the surface insulation element (6) so that the interconnection element (1) is enclosed in a tube-like manner by the surface insulation element (6), d) fixing the first edge (7) relative to the second edge (8) of the surface insulation element (6) by means of a material connection and / or a form fit. Method according to claim 5 or 6, characterized in that Before inserting the interconnection element (1) into the surface insulation element (6), the surface insulation element (6) is pre-formed into a contour with a V- or U-shaped cross section.

8. Method according to one of claims 5-7, characterized in that the pre-forming of the surface insulation element (6) takes place by means of a forming tool (13) which has a channel (14) which is open on one side in cross-section, in particular a V- or U-shaped channel (14), in which the surface insulation element (6) is inserted.

9. Method according to claim 8, characterized in that the surface insulation element (6) is drawn and / or held into the channel (14) by means of a negative pressure.

10. Method according to one of the preceding claims 5-9, characterized in that the channel (14) has two channel wings (15, 16) which are movable relative to one another. 11 . Kit-of-parts (20) for producing insulation of a wiring element (1 ) for electrically contacting two contact elements (2) spaced apart from one another, comprising: • A plurality of interconnection elements (1) each for electrically contacting two contact elements (2) spaced apart from one another, each having a first wire end (3) and a second wire end (4), • A plurality of surface insulation elements (6), each of which has a first insulation element extending in the longitudinal direction of the interconnection element (1) Edge (7) with a first adhesive strip (17) and a second edge (8) extending in the longitudinal direction of the interconnection element (1), • A molding tool (13) which has a cross-sectionally open one side Channel (14), in particular a V- or U-shaped channel (14), in which the surface insulation element (6) can be inserted.

Images