EP2946461A2

EP2946461A2 - Contact element for an electric machine

Info

Publication number: EP2946461A2
Application number: EP13805326.9A
Authority: EP
Inventors: Thomas Devermann; Andreas Ewert; Jan Schlegel; Lukas Leitz
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2013-01-18
Filing date: 2013-12-06
Publication date: 2015-11-25
Also published as: WO2014111200A2; DE102013200794A1; WO2014111200A3; JP2016505235A; JP6129345B2; CN104904100A; US20150318768A1

Abstract

The invention relates to a contact element (10; 10'; 10''; 10''') for providing an electrical contact to an electric machine, particularly in a motor vehicle, comprising: a first contact section (13; 14; 18; 21') formed from a first material; and a second contact section (11; 17'; 11; 23) formed from a second material that is different from the first material, wherein the first contact section and the second contact section are connected by means of a multi-component connection (16; 16'; 16''; 16''').

Description

description

title

Contacting element for an electrical machine

TECHNICAL FIELD The invention generally relates to a contacting element for an electrical machine, in particular in a motor vehicle.

PRIOR ART Commutators are known as current inverters in electric motors, the commutators consisting of a thermosetting molding compound as carrier and lamellae of copper.

The lamellae serve both as an electrical contact surface to the current-carrying carbon brushes and to winding wires of a rotor winding, which are currently formed in most electrical machines made of copper. The winding wires are installed in electrical machines such that they form a winding arrangement in order to be able to form a magnetic flux. The electrical contact from the blade to the winding wire may be formed via a contacting hook provided at the end of the commutator blade. In an inner region of a Kontaktierhakens may be provided to improve the contacting a partial tinning. To make the contact, the end of a winding wire of the rotor winding in the

Contact hook inserted and pressed.

Since copper is expensive as a winding material, is looking for cheaper replacement. Thus, winding wires made of aluminum instead of copper are increasingly being considered today. In the case of using aluminum wire for contacting with a copper-made contacting hook of the commutator, methods based on soft soldering are known. However, these are disadvantageous in terms of durability at permanently sustained high operating temperatures of the electrical machine. Also, a mechanical load capacity of such an arrangement is not sufficient.

Further, in the contacting between the copper of the commutator and the material of the winding arrangement of the contact resistance may increase, since unstable intermetallic phases may occur.

During assembly and attachment to the commutator, the winding wire can be crushed, thereby reducing its wire cross-section. Therefore, the wire cross section for the rotor winding in providing a constricting crimping of the winding wire to the contacting hook is chosen to be larger than would be necessary for the electrical properties of the electrical machine. This leads to limitations of the construction of the electric machine.

It is therefore an object of the present invention to provide an improved contacting element in a simple manner, in particular one which provides reliable contacting between a connection of an electrical machine and a conductor to a winding arrangement in the electrical machine, in particular in one of material of the conductor different from the material of the terminal. Disclosure of the invention

This object is achieved by a contact element for an electrical contact in an electrical machine, preferably in a motor vehicle, according to claim 1, a contacting arrangement according to the independent claim 8 and by an electric machine, in particular in a motor vehicle, according to the independent claim 11.

Further advantageous embodiments of the present invention are specified in the dependent claims. According to a first aspect, a contacting element is provided for providing an electrical contact to an electrical machine, in particular in a motor vehicle, comprising: a first formed from a first material

contacting section; and a second contacting portion formed of a second material different from the first material, wherein the first contacting portion and the second contacting portion are connected by a multi-material connection.

One idea of the above contacting element is to provide electrical contact between a connection of the machine and a conductor to a winding arrangement in the interior of the electrical machine in such a way that a fabric-like or at least material-compatible contacting is provided from the contacting element to the winding arrangement.

In this way, it is possible to connect the winding arrangement electrically to the contact element without a multi-substance connection being produced at this connection area. By a multi-compound compound can form intermetallic phases, which have a significantly increased contact resistance. This is disadvantageous for the electrical properties of the electrical machine. This disadvantage is avoided by the proposed contacting in the region of contact between the winding assembly and the power supply.

The Kontaktierelement provided as described allows a largely free choice of the winding material. Since a relatively large amount of winding material is required for the winding arrangement, it is possible to switch to a less expensive winding material without technical losses if the winding material used hitherto has become too expensive for economical use.

In other words, it is possible in this way to make a high amount of material in a winding arrangement inexpensive, while ensuring an electrically good and mechanically reliable contact for connecting the machine.

It is contemplated to provide a prefabricated as described contacting, so that in a manufacture of the electrical machine, when contacting the winding assembly, only a fabric-like or at least Stoffgelegäg Liehe contacting between the winding assembly and the prefabricated contacting is made, so that the production of the electric machine simple and den- still a mechanically stable and temperature-resistant, good electrical contact is provided from outside via a connection of the electric machine to the winding arrangement. Under a substance contractual lending contacting is understood in particular a contact between different materials in which no or substantially no intermetallic phases occur, or between different, but largely similar materials understood. In the present case, a contacting element is therefore understood in particular to mean a construction which provides an electrically conductive contact or an electrically conductive connection between a connection to the electrical machine and a winding arrangement of the electrical machine or a conductor to the winding arrangement.

By a multi-substance compound is meant in particular a compound which is formed from at least two different, conductive materials.

A contacting element, which as described has a first contacting section made of a first material and a second contacting section connected thereto via a multi-material connection and made of a second material different from the first material, may be referred to as a multi-component system.

A first contacting section is to be understood here in particular as the section of the contacting element which is assigned to the winding arrangement. In other words, the first contacting section is connected either directly to one end of a winding of the winding arrangement or to a conductor leading to the winding arrangement. By winding material is meant the material that makes up the conductive components of the winding assembly. In a DC motor, the first contacting portion may be designed as a commutator hook or slot.

The first material of the contacting element may be identical to the winding material. Alternatively, the first material of the contacting element may be compatible with the winding material. In this case, a second contacting section is to be understood as meaning, in particular, the section associated with the connection of the electrical machine. Furthermore, the contacting element can be designed such that the winding-side contacting section is connected directly to the feed-side contacting section and thus the multi-substance compound is provided.

Alternatively, the contacting element can be designed such that the winding-side contacting section is connected indirectly to the feed-side contacting section via a contacting section providing the multi-material connection.

It can be provided that the winding material of the electrical machine is essentially formed from aluminum. Since aluminum is cheaper than copper, a total cost saving is provided in this way. It is considered to provide a conductor which electrically connects the first contacting portion of the contacting element with the winding material. Alternatively, it is provided that one end of a winding is electrically connected directly to the first contacting section of the contacting element.

In particular, in the case of using aluminum as the winding material, its insulation may be formed by means of anodization. It is therefore unnecessary to wire coating required in the conventional case of copper wire as the winding material.

According to one embodiment, the second contacting portion of the

Contacting element may be formed essentially of copper. This is the conventionally used material, for example, the fins of a commutator of a DC motor or the feed lines from an electronic commutator to winding terminals of an electronically commutated (EC) motor.

It is contemplated that a contacting element may be formed with a first contacting portion formed of aluminum or aluminum and a second portion formed of a second material compatible with copper or copper

Contacting section, wherein the first contacting section of the winding arrangement is assigned and the second Kontaktierabschnitt is associated with the connection of the electrical machine.

It can be provided that the electric machine is one of a direct current motor, an EC motor, a generator and a transformer. In the case of a DC motor, the contacting element will be provided on the commutator and provide electrical contact between a commutator blade and a line to the winding assembly. The energy supply from the outside is then done in a conventional manner via a carbon brush, which grinds on the commutator and alternately has contact with one blade at a time when the commutator rotates.

In the case of an EC motor, a control terminal of a suitable control device for supplying and driving a field winding arrangement is connected to the supply-side contacting section. In this case, it is considered to design a rotor of the EC motor as a permanent magnet.

In the event that the electrical machine is a transformer, it is considered to use the described contacting element at least on the side of the transformer on which the winding arrangement has the most windings.

According to an embodiment, the multi-material compound of the winding-side contacting portion with the feeding-side contacting portion may be replaced by one of TIG, TIG, MIG, MAG, resistance, frictional welding, laser welding, flux soldering and solderless solder jointing, as well as be provided with or without ultrasound support. In this way, a mechanically and thermally stable connection is provided between the winding-side contacting section and the feeding-side contacting section.

According to another aspect, there is provided a contactor assembly comprising a contactor as described above and a conductor connecting the winding-side contacting portion to the winding assembly, wherein the conductor is formed of at least a portion of the winding-side contacting portion of two portions formed of different materials. According to yet another aspect, an electric machine, in particular in a motor vehicle, is provided, wherein a contact between a power supply and a winding arrangement in the electric machine is formed by a contacting element as described above and / or by a contacting arrangement as described above.

The contact element described provides a robust contact and a constant low contact resistance.

In the case of a DC motor, for example, a carrier made of a plurality of materials, at least two, is used. This may be, for example, copper and aluminum. The carrier material can be produced by roll-plating or friction-welding.

A construction as described above can be demonstrated, for example, by disassembling the electrical machine and by grinding patterns as well as by suitable physical and chemical analyzes.

Brief description of the drawings

Preferred embodiments of the present invention will be explained in more detail with reference to the accompanying drawings. Here, similar reference numbers are used for similar or similar acting components, unless otherwise noted. Show it:

1 shows a cross section through an electric machine designed as a brushed DC motor;

Figures 2a - 2b serving as an explanation serving schematic representations

embodiment;

FIGS. 3a-3i show schematic representations of embodiments in which a winding-side conductor is fastened to a winding-side contacting section in the form of a commutator hook; FIGS. 4a-4b show a schematic representation of embodiments in which a winding-side conductor is fastened to a winding-side contacting section in the form of a slot; and

FIGS. 5a-5d show a schematic representation of embodiments in which a winding-side conductor is welded to a winding-side contacting section. Description of embodiments

FIG. 1 shows a partial cross section through an electric machine M designed as a brushed DC motor. The electric machine M has a housing 8 in which an armature A is held on a bearing 6 via a shaft 4 assigned to it. It is not shown that the shaft 4 is further held at its opposite end to a second bearing.

The electric machine M also has a commutator 3. The commutator 3 comprises slats 5, which are contacted via carbon brushes 1 and 2. For this purpose, the carbon brushes 1 and 2 touch lamellae 5 of a commutator 3 formed in lamellae and in this way establish electrical contact between a connection, not shown, and a winding arrangement, not shown, in this case an armature winding arrangement. A contacting portion 7 provides contact between the blade and a conductor 15 leading to the winding assembly.

A current supply for the winding arrangement of the armature A via the commutator 3 formed in lamellae 3 via the carbon brushes 1 and 2. If the armature A is supplied in this way with electricity, so an armature magnetic field is formed, which is connected to an existing stator Magnetic field interacts in such a way that torque acts on the armature A, so that it rotates. In this case, the carbon brushes lose contact with the previously contacted lamellae of the commutator and get a contact in the direction of rotation next slats of the commutator, which are assigned to another winding arrangement at the anchor, so that in turn an armature magnetic field is formed, which in turn with the existing stator - Magnetic field interacts in such a way that a force acts on the armature A, so that it continues to rotate. In other words, the commutator serves to Ker constant magnetic field at a predetermined angle to the stator magnet to be generated such that continuously a substantially constant torque can act on the armature A. Figures 2a -2b show for explanation in detail a schematic representation of an embodiment. FIG. 2 a shows a simple illustration of an embodiment: A contacting element 9, which functionally corresponds to the contacting element 7 from FIG. 1, is made of a first contacting section 21 formed of a first material and a second contacting section formed thereon of a second material 23 formed. A conductor 15 leads to a winding arrangement, not shown, of an electrical machine.

The conductor 15 is formed of the same material as the first contacting portion 21 or at least of a compatible material that forms no or substantially no intermetallic phase with the first material.

The second contacting portion 23, on the other hand, is formed of a second material different from the first material. The contacting section 23 is connected via a stripped end 25 of a feed conductor 24, which is formed from the second material, to a connection (not shown) of the electrical machine. Incidentally, the feed conductor 24 is provided here with insulation 27.

In this way, the winding arrangement is the same material or material compatible with the first contacting portion 21 of the contacting element 9 and the connection material equal or material compatible with the second contacting portion 23 of the contacting element 9. The mass transfer between the first material and the second material is thus provided by the contacting element 9, in that a solid multi-substance compound has been created between the first contacting section 21 and the second contacting section 23.

Thus, a mechanically and thermally stable electrical connection between the terminal and the winding assembly is provided because either fabric-like compounds or a particularly stable provided between the different materials compound is provided. Starting from this rather isolated exemplary consideration, a contacting element 7 of FIG. 1, here as contacting element 10 "', is shown schematically in FIG. 2b. A first contacting section 21', also referred to as commutator hook 21 ', formed on the first material is on one side The first material can be identical to the material from which the windings of the electric machine are formed, for example aluminum Furthermore, the commutator has a contacting section 23, also referred to as a lamella 23, formed from the second material and assigned to the connection of the electrical machine.

FIGS. 3a-3i show schematic representations of embodiments in which a winding-side conductor is fastened to a winding-side contacting section in the form of a commutator hook.

According to one embodiment, a contacting element 10 serves to provide an electrical contact between a connection of an electrical machine and a winding arrangement formed from a winding material in an electrical machine. The contacting element 10 has a winding-side contacting section 13 formed from a first material, which may be a winding material or a material compatible therewith, and a second contacting section 11a to 11a formed from a second material different from the winding material and associated with the terminal wherein the first contacting portion 13 and the second contacting portion 1 1 a. to 1 1 i are connected by means of a multi-substance compound 16a to 16i.

In the case of a brush-type DC motor, the winding-side contacting sections 13 will be, for example, commutator hooks 13. The commutator hook 13 is formed of a section aligned with the commutator blade and resting on the commutator carrier, and a portion bent back at an angle from the commutator carrier to which one end of a conductor 15 leading to the coil assembly is attached. In the simplest case, a commutator hook may be formed by a first protruding beyond the commutator and then bent back lamella. Further, the end of the conductor 15 connected to the commutator hook can be bent by bending back the projecting portion the lamella be clamped such that it is held on the lamella providing a conductive connection.

Via the second contacting portion 11a to 11f connected to the terminal, an electrical connection can thus be created via the first contacting portion 13 to the conductor 15 and thus to the winding arrangement.

Common to the embodiments shown in FIGS. 3a-3i is that a winding-side or first contacting section 13 made of a winding material or of a material compatible with the winding material, which is referred to as the first material, is in electrical contact with a conductor 15 is, which is also made of the winding material and leads to a winding arrangement. It is contemplated that the winding assembly is formed entirely of the conductor 15.

The winding-side contacting portion 13 may, for example, a

Represent Kommutatorhaken. In this case, a supply-side

3a shows a contacting element 10. A first contacting section 13, which is formed from a first material, is directly connected to a contacting section 17a which provides a multi-material connection and which is likewise formed from the first material is. The first contacting portion 13 is bent back such that a conductor 15 can be clamped between the first contacting portion 13 and the contacting portion 17 a. The Kontaktierabschnitt 17a is - as shown in the cross section - a large area electrically connected to a second Kontaktierabschnitt 1 1 a, wherein the second Kontaktierabschnitt 1 1 a is formed of a second material. The second contacting portion 11a is connected to the contacting portion 17a via a multi-junction 16a, which is characterized by one of TIG, TIG, MIG, MAG, resistance, frictional welding, laser welding, flux soldering and Solder connection is provided without flux. The aforementioned methods can also be supported by means of an ultrasonic method. In other words, the second contacting portion 1 1 a appears parallel to a longitudinal extension direction of the Kontaktierabschnitts 17 a placed thereon. The first contacting section 13 is thus indirectly connected to the second contacting section 11a via the contacting section 17a providing the multi-substance connection 16a. According to FIG. 3b, a first contacting section 13 made of a first material is provided, which is connected directly to a contacting section 17b. The first contacting portion 13 is bent back with respect to the contacting portion 17 b so that a conductor 15 between the first contacting portion 13 and the

Contacting portion 17b can be jammed. In the longitudinal direction of extension of the contacting portion 17b formed of the first material, a second contacting portion 11b formed of a second material is abutted against it. A multi-substance compound 16b formed between the contacting portion 17b and the second contacting portion 11b has a smaller area than in the preceding example.

The first contacting section 13 is thus indirectly connected to the second contacting section 11b via the contacting section 17b providing the multi-material connection 16b. FIG. 3c shows a contacting element 10 in which a first contacting section formed from a first material is connected directly to a second contacting section 11c formed from a second material. The first Kontaktierabschnitt is connected via a multi-compound 16c with the second Kontaktierabschnitt 1 1 c. In other words, the second contacting portion 11c is provided integrally with the contacting portion 17c. The first contacting portion 13 has such an acute angle with the contacting portion 17c that a conductor 15 between the first contacting portion 13 and the contacting portion 17c can be jammed. The multi-material compound 16c between the first contacting portion 13 and the contacting portion 17c may be made in any of the aforementioned manners.

The first contacting portion 13 is thus directly with the second

Kontaktierabschnitt 1 1 c, so that in this way the multi-compound 16c is provided. FIG. 3d shows a contacting element 10, in which a first contacting section 13 formed from a first material is indirectly connected to one of a second material formed Kontaktierabschnitt 1 1 d is connected. The first contacting portion 13 is directly connected to a contact portion 17 d and takes with this an acute angle, that a conductor 15 between the first contacting portion 13 and the contacting portion 17 d can be clamped. The contacting portion 17d tapers stepwise in its longitudinal direction, as seen from the junction with the first contacting portion 13. In the stage, the second contacting portion 1 1 d. Between the second Kontaktierabschnitt 1 1 d and the Kontaktierabschnitt 17d a multi-compound 16d is created. The first contacting section 13 is thus indirectly connected to the second contacting section 11 d via the contacting section 17 d providing the multi-substance connection 16 d.

FIG. 3e shows a contacting element 10, which has a first contacting section 13 formed from a first material, which is formed on a contacting section 17e formed from the first material. The first contacting portion 13 has such an acute angle with the contacting portion 17e that a conductor 15 between the first contacting portion 13 and the contacting portion 17e can be jammed. The contacting section 17e has a recess into which a second contacting section 11e formed from a second material is embedded. Between the second Kontaktierabschnitt 1 1 e and the Kontaktierabschnitt 17e a multi-compound 16e is created.

The first contacting section 13 is thus indirectly connected to the second contacting section 11e via the contacting section 17e providing the multi-material connection 16e.

FIG. 3f shows a contacting element 10. A first contacting section formed from a first material is formed on a contacting section 17f and has an acute angle therewith such that a conductor 15 is arranged between the first

Contacting section 13 and the Kontaktierabschnitt 17f can be jammed. In the extension direction of the Kontaktierabschnitt 17f, seen from the first

Kontaktierabschnitt, is formed of a second material second

Contacting section 1 1 f connected on push. Between the second

Kontaktierabschnitt 1 1 f and the Kontaktierabschnitt 17f is a multi-compound 16f created. The first contacting section 13 is thus indirectly connected to the second contacting section 11f via the contacting section 17f providing the multi-material connection 16f.

FIG. 3g shows a contacting element 10 in which a first contacting section 13 formed from a first material is applied to a contacting section 17g formed from the first material. The first contacting portion 13 and the

Contacting portion 17g occupy each other at such an acute angle that a conductor 15 between the first contacting portion 13 and the contacting portion 17g can be clamped. The contacting portion 17g is recessed in a step of a second contacting portion 11g formed in a stretching direction of the contacting portion 17g, as viewed from the first contacting portion 13, which is steppedly enlarged. Between the second Kontaktierabschnitt 1 1 g and the Kontaktierabschnitt 17g a multi-compound 16g is created.

The first contacting section 13 is therefore indirectly connected to the second contacting section 11 g via the contacting section 17g providing the multi-substance connection 16g.

FIG. 3h shows a contacting element 10 in which a first contacting section 13 formed from a first material is fastened to a second contacting section 11 formed of a second material. The first Kontaktierabschnitt 13 takes with the second Kontaktierabschnitt 1 1 h such an acute angle that between a see the first Kontaktierabschnitt 13 and the second Kontaktierabschnitt 1 1 h arranged conductor between the first Kontaktierabschnitt 13 and the second Kontaktierabschnitt 1 1 h are clamped can. The first contacting portion 13 is directly connected to the second contacting portion 1 1 h via a multi-substance compound 16h. In this embodiment, a contacting portion 17h is identical to the second contacting portion 11h.

The first contacting portion 13 is thus directly with the second

Kontaktierabschnitt 1 1 h, so that in this way the multi-compound connection 16h is provided. FIG. 3i shows a contacting element 10, in which the first contacting section is formed from a section of a first material 13.2 and a section of a further material 13.1. The first contacting portion 13 is formed on the side 13.2 formed of the first material with a material formed of the first material

Contacting section 17i connected. The first contacting portion 13 and the

Contacting portion 17i occupy such an acute angle that a conductor 15 interposed between the side 13.2 of the first contacting portion 13 and the contacting portion 17i formed from the first material can be jammed therebetween. The contacting portion 17i is recessed in a recess of a second contacting portion 11a formed in a stepwise direction of the contacting portion 17i, as viewed from the first contacting portion 13, stepwisely widening from a second material. The contacting portion i is connected to the contacting portion 17i via a multi-material compound 16i. The first contacting section 13 is thus indirectly connected via its section formed from the first material 13.1 to the second contacting section 11 via the contacting section 17i providing the multi-substance compound 16i.

Figures 4a and 4b are schematic representations of embodiments in which the winding-side conductor is attached to a winding-side contacting portion in the form of a slot.

In detail, two embodiments of FIGS. 4a-4b are shown

Kontaktierelements 10 'shown in which a winding material formed from the winding side contacting portion 14a, 14b is provided with a slot. The conductor 15 likewise formed from the winding material is inserted into the slot for contacting and fixed, for example, by pressing or Leitkleben or welding. In the embodiment according to FIG. 4a, the slot in the contacting section 14a is made up to the feed-side contacting section 17'a formed from the second material.

In contrast, according to FIG. 4b, the slot is formed completely within the winding-side contacting section, so that in the manufacture of the contacting between the conductor 15 and the winding-side contacting section 14b, the conductor extends up to can be pushed through down without a multi-substance compound would arise.

The Kontaktierabschnitt 17'a and 17'b is connected directly in this embodiment with the feed side contacting portion 1 1 and thus forms a multi-compound 16 '.

FIGS. 5a-5d show schematic representations of four embodiments 10 "of a contacting element with feed-side contacting surface 11 and welded conductor 15.

According to FIG. 5a, a winding-side material is formed from winding material

Contacting portion 18a with the feed side contacting surface formed from the second material 1 1 frontally connected butt and thus forms a multi-compound 16 "on the winding-side contacting portion 18a is formed from the winding material, leading to the winding assembly leading conductor 15 is welded.

The conductor 15 leading to the winding assembly is formed of the winding material and welded or soldered or conductively bonded to the winding-side contacting portion 18a.

FIG. 5 b shows, in a modification of the representation of FIG. 5 a, that the contacting surface 1 1 is formed only in a surface section of a winding-side contacting section 18 b formed from the winding material. The multi-compound 16 "thus has the shape of a half trough.

The contacting element shown in FIG. 5c corresponds to that shown in FIG. 5a, except that here the conductor 15 which leads to the winding arrangement is formed from two different materials. Namely, the conductor 15 is formed at least in a portion of the winding-side contacting portion 18c from a portion 15.2 formed of the winding material and a portion 15.1 made of another material. The portion 15.2 formed of the winding material is welded to the winding side contacting portion 18c of the contacting member 10 ", and the portion 15.1 formed of the other material is of the winding side

Contacting portion 18c of the contacting 10 'facing away. The contacting element shown in FIG. 5d corresponds to that shown in FIG. 5b, except that here the conductor 15 leading to the winding arrangement is formed as in the embodiment shown in FIG. 5c.

The contacting section 17 "a to 17" d providing the multi-substance compound 16 "is in each case connected directly to the supply-side contacting section 11 in the embodiments shown in Figures 5a to 5d Kontaktierabschnitts with the feed-side contacting portion by one of TIG, TIG, MIG, MAG, resistance, friction welding, laser welding, solder joint with flux and solder joint without flux, and with or without ultrasound support, is provided.

Moreover, a contacting arrangement is contemplated, comprising a contacting element as described above and a winding side

Contacting section with the winding arrangement connecting conductors 15, wherein the conductor 15 is formed of two sections 15.1, 15.2 formed of different materials.

Finally, an electric machine, in particular in a motor vehicle, is provided, which is formed in such a way that contact with a winding arrangement in the electric machine is formed by a contact element formed as above and / or by a contact arrangement provided as above.

Claims

claims

1 . Contacting element (10; 10 '; 10 "; 10"') for providing an electrical contact to a winding arrangement of an electrical machine, in particular in a motor vehicle, comprising:

a first contacting portion (13; 14; 18; 21 ') formed of a first material; and

a second contacting portion (11; 17 '; 11; 23) formed of a second material different from the first material, the first contacting portion (13; 14; 18; 21') and the second contacting portion (13;

Contacting section (1 1; 17 '; 1 1; 23) are connected by means of a multi-material connection (16; 16'; 16 "; 16 '').

2. contacting element according to claim 1, wherein the first contacting portion (13;

14; 18; 21 ') is directly connected to the second contacting section (1 1 c; 1 1 h; 17'; 1 1; 23) and thus the multi-substance compound (16c; 16h; 16 '; 16 "; 16"') is provided.

3. contacting element according to claim 1, wherein the first contacting portion (13) indirectly with the second contacting portion (1 1 a; 1 1 b; 1 1 d; 1 1 e; 1 1 f; 1 1 g; I ii) via a the 16i; 16b; 16d; 16e; 16f; 16g; 16i) is provided with the third contacting portion (17a; 17b; 17d; 17e; 17f; 17g; 17i).

4. Contacting element according to one of the preceding claims, wherein the first material is formed substantially from or with aluminum or an aluminum-compatible material.

5. Contacting element according to one of the preceding claims, wherein the second material is formed substantially from or with copper or a copper-compatible material.

6. Contacting element according to one of the preceding claims, wherein the electric machine is one of a DC motor, an EC motor, a generator and a transformer.

Contacting element according to one of the preceding claims, wherein the multi-material connection (16; 16 '; 16 "; 16"') of the first contacting section (13; 14; 18; 21 ') is connected to the second contacting section (1 1; 17'; 1, 23) is provided by one of TIG, TIG, MIG, MAG, resistance, friction welding, laser welding, flux soldering and solderless solder jointing, and with or without ultrasonic assistance.

Contacting arrangement for providing an electrical contact to a winding arrangement of an electrical machine, in particular in a motor vehicle, comprising

a contacting element (10; 10 '; 10 "; 10"') according to any one of the preceding claims; and

a conductor (15) connecting the first contacting portion (18c; 18d) of the contacting member to the winding assembly.

Contacting arrangement according to the preceding claim, wherein the conductor (15) at least in the region of the first Kontaktierabschnitts (18c, 18d) of a third material formed from a first conductor portion (15.1) and formed of a fourth material, with the first contacting portion (18c; 18d) connected to the second conductor section (15.2) is formed.

A contacting arrangement according to the preceding claim, wherein the fourth material is identical or compatible with the first material.

Electrical machine, in particular in a motor vehicle, wherein a contact between a connection of the machine and a winding arrangement in the electric machine is formed by a contacting element according to one of claims 1 to 7 and / or by a contacting arrangement according to one of claims 9 to 10.