ELECTRIC MOTOR WITH A CIRCUIT UNIT AND METHOD FOR MANUFACTURING AN ELECTRIC MOTOR WITH A CIRCUIT UNIT

Description

[0001] The invention relates to an electric motor with a switching unit and a method for its manufacture.

[0002] It is generally known that an electric motor has a stator on which a multi-phase winding is arranged. This winding consists, for example, of several interconnected coils. Stators are also known that are constructed from wound individual teeth, where each stator tooth accommodates a single tooth winding. In this case, each individual tooth winding forms a coil made of winding wire. The free ends of a winding wire form the two coil terminals of a coil, which are usually connected to one or both axial ends of the stator to form the multi-phase winding. Star and delta connections are known configurations.

[0003] The present invention is particularly suitable for synchronous motors whose stators are constructed from individual stator tooth segments, each stator tooth segment comprising a coil, i.e., a single tooth winding. These synchronous motors particularly feature a three-phase winding with phases U, V, and W, with each phase preferably being assigned a coil group. A coil group, in turn, comprises several individual coils, these coils being electrically connected to one another by means of the interconnection unit according to the invention. Thus, a coil terminal of one coil is contacted with another coil terminal of another coil by means of an interconnection element of the interconnection unit. The coil groups connected in this way are preferably connected to one another in a star configuration.

[0004] Various types of coil connection wiring are known from the state of the art.

[0005] From DE 11 2013 005 061 T5 a stator unit and a motor are known, wherein a busbar unit is arranged on a top side of the stator.

[0006] From DE 10 2012 024 581 A1 an electric motor with a connecting ring is known in which wire sections are inserted into concentrically extending, radially spaced grooves.

[0007] From DE 10 2012 020 329 A1, an electric motor with a connecting ring is known in which electrical conductors, in particular designed as stamped and bent parts, are inserted into concentrically extending, radially spaced grooves.

[0008] From DE 103 28 720 A1, an electrical machine with a ring-shaped support and with conductor tracks arranged in the support for the electrical connection of coils and winding strands is known. The conductor tracks are arranged vertically one behind the other and offset from each other in the circumferential direction within the support.

[0009] From DE 10 2014 201 637 A1 an electric motor with a carrier component is known in which the winding ends are connected by means of multi-part busbars.

[0010] From EP 2 752 973 A1, an electric motor with a connecting ring is known in which circular arc-shaped busbars are inserted into two annular grooves of the connecting ring.

[0011] From DE 10 2016 204 935 A1 an electrical machine with a connection plate is known in which conductor elements are used for connecting the windings, wherein the conductor elements are overmolded with plastic for insulation.

[0012] From DE 10 2015 200 093 A1, a connection plate of a stator of an electrical machine is known, wherein the connection plate has conductor elements which can be connected to the electrical winding.

[0013] WO 2017 078 455 A1 discloses a switching unit, a motor and a power transmission system.

[0014] From US patent 2008 136 274 A1, a motor, stator, wire and a manufacturing process thereof are known.

[0015] A stator for an electric lathe is known from US 2013 200 743 A1.

[0016] A stator winding structure of a motor or generator is known from US 2005 189 833 A1.

[0017] The invention is therefore based on the objective of further developing an electric motor with a circuit unit and a method for its manufacture, whereby the manufacturing effort is reduced and the electric motor can be manufactured more easily, cost-effectively and stably.

[0018] According to the invention, the problem is solved in the method according to the features specified in claim 1 and in the method according to the features specified in claim 13.

[0019] Important features of the invention for the electric motor, in particular a permanent magnet synchronous motor, with a rotor rotatably arranged about an axis of rotation and with a stator, are that the stator has several coils, each coil having two coil terminals, in particular that the stator has several stator segments and each stator segment has exactly one coil, wherein the coils are interconnected by means of a connection unit, in particular in a star connection, wherein the connection unit comprises a support part, in particular a substantially annular support part, in particular a support part made of an insulating material, for receiving several, in particular at least four, interconnection elements spaced apart from one another, in particular wherein the connection unit is arranged at an axial end of the stator, in particular concentrically to the axis of rotation, wherein at least three first interconnection elements are provided.wherein each of the first interconnection elements has two, in particular exactly two, spaced-apart contact areas and a connection area connected to the contact areas, in particular such that the connection area is arranged between the contact areas, wherein the, in particular all, contact areas of each first interconnection element are each electrically connected to one of the coil terminals at a connection point, in particular by means of laser welding, wherein the area covered by the connection area of ​​one of the first interconnection elements in the circumferential and radial direction overlaps an area covered by the connection area of ​​another of the first interconnection elements in the circumferential and radial direction.

[0020] The terms "circumferential direction," "radial direction," and "axial direction" refer to directions relative to the rotor's axis of rotation. Axial direction thus denotes the direction parallel to the axis of rotation, while radial direction denotes directions perpendicular to the axis of rotation and radially outward from the axis of rotation, or radially inward toward the axis of rotation. Circumferential direction is understood as the direction that runs along the circumference of a closed curve, particularly a circle, that is perpendicular and, in particular, concentric to the axis of rotation. The term is therefore not limited to circular circumferences but can also be used for, for example, elliptical or polygonal circumferences.

[0021] The term "essentially ring-shaped support element" means that the support element is disk-shaped, i.e., it has a continuous opening in the center, and its axial extent is smaller than the diameter of the support element in the plane perpendicular to the axis of rotation. The exact contours of the outer and inner surfaces are not necessarily circular, as with a ring. Other shapes are conceivable, such as polygonal forms. It is also possible for the shape to deviate from a perfect circle, for example, by having cutouts on the outer or inner circumference.

[0022] Plastic is preferably used as the insulating material for the support component. In particular, the support component is manufactured using a plastic injection molding process. However, other materials that possess electrical insulating properties, i.e., insulating materials, can also be used.

[0023] The carrier part holds the interconnection elements, thus ensuring their spatial arrangement relative to one another. The interconnection elements are spaced apart from each other; they do not touch and are therefore not in direct contact.

[0024] Instead of laser welding, brazing, ultrasonic welding or resistance welding can also be used.

[0025] The interconnection elements are made of an electrically conductive material, preferably metal or sheet metal, and in particular copper sheet. The interconnection elements are preferably manufactured in one piece and / or preferably as stamped and bent parts. They can be manufactured by waterjet cutting or laser cutting.

[0026] The term "connection point" refers to the location where an electrical connection exists between a switching element and a coil terminal.

[0027] The term "area" refers to a specific part of a component that fulfills a particular function. For example, the connection area of ​​the first interconnect element links the two contact areas. These contact areas, in turn, serve to connect the interconnect elements to the coil terminals. When a component is manufactured as a single piece, a precise demarcation between the areas is not always possible. The area of ​​a component should not be confused with an area of ​​the component that is "covered" in one direction.

[0028] Each first interconnection element mounted on the carrier part is arranged axially above or below at least one other first interconnection element. The first interconnection elements are thus partially stacked on top of each other axially, without, however, touching each other. The area covered in the circumferential and radial directions of a connection section is the surface created by projecting the corresponding connection section parallel to the axial direction onto a projection plane perpendicular to the axis of rotation. The resulting projection surfaces of the connection sections of any two first interconnection elements therefore overlap in the projection plane.

[0029] An advantage of this is that a compact design for the wiring unit can be achieved.

[0030] According to the invention, the first interconnection elements are of identical construction.

[0031] An advantage of this approach is that fewer different types of interconnection elements need to be manufactured, thus reducing production costs. The interconnection unit can be manufactured using only one type of initial interconnection element. This particularly facilitates the automated production of the initial interconnection elements, for example, when they are machine-made as stamped and bent parts.

[0032] In an advantageous embodiment, the areas covered by the connection areas of the first interconnection elements in the axial direction are equal.

[0033] An advantage of this is that space can be saved in the axial direction, so that a compact design of the interconnection unit can be achieved in the axial direction.

[0034] In an advantageous embodiment, the areas covered by the connection areas of the first interconnection elements in the radial direction are equal.

[0035] An advantage of this is that space can be saved in the radial direction, so that a compact design of the interconnection unit can be achieved in the radial direction.

[0036] In an advantageous embodiment, the contacting areas of each first interconnection element are shaped such that the respective connection points each have essentially the same radial position, in particular on the outer circumference of the carrier part, and / or the same axial position.

[0037] A key advantage is the ease of connecting the contact areas to the coil terminals. This allows for automated assembly. Furthermore, the connection points are conveniently located on the outer circumference of the carrier part, ensuring easy accessibility.

[0038] In an advantageous embodiment, the connection area of ​​each of the first interconnection elements has a cross-section, in particular an approximately rectangular one, whose axial extent is smaller than its radial extent. The advantage here is that installation space in the axial direction can be saved.

[0039] In an advantageous embodiment, at least one connection area of ​​one of the first interconnection elements has two axial steps, particularly wherein all connection areas of the first interconnection elements each have two axial steps. An advantage of this is that partial stacking of the first interconnection elements is simplified. Instead of discrete steps in the connection area, an axially inclined, and in particular constant, inclination of the connection area is also possible, so that the two contact areas have different axial positions and partial stacking is enabled.

[0040] In an advantageous embodiment, each of the first interconnection elements has a first fastening area for a positive-locking and / or material-locking connection with the support part, in particular wherein each of the first fastening areas has a first axially extending recess and the support part has several axially extending rivet pins, in particular wherein a first rivet pin can be passed through each of the first recesses, in particular wherein the free ends of the first rivet pins are formed into rivet heads, in particular by means of ultrasonic welding.

[0041] The advantage of this method is that a secure and stable, and in particular permanent, connection between the interconnection elements and the carrier component can be achieved, thus ensuring a secure, non-removable connection. Hot riveting or hot stamping are also possible alternatives to ultrasonic welding.

[0042] The recess can be designed, for example, as a cylindrical hole. A hole is an example of a closed recess. However, open recesses are also conceivable, which do not form a closed curve in the plane perpendicular to the axis of rotation. For example, an indentation in the axial direction also constitutes a recess. The essential requirement is that the recess extends continuously in the axial direction and is suitable for contributing to a positive-locking and / or material-locking connection with the supporting part.

[0043] A rivet pin is defined as an axially extending projection shaped to pass through the recesses of the first connecting elements. In the example of a cylindrical hole as the recess, the rivet pin is designed as a cylindrical axial projection. Forming the free end of the rivet pin into a rivet head creates a positive-locking and / or material-locking connection. Mushroom-shaped or disc-shaped rivet heads are suitable for achieving a positive-locking connection. The diameter of the rivet head in the plane perpendicular to the axis of rotation is larger than the diameter of the corresponding recess in the same plane.

[0044] In an advantageous embodiment, each of the first connecting elements has a second fastening area for a positive-locking and / or material-locking connection with the carrier part, in particular wherein each of the second fastening areas has a second axially extending recess, wherein a second rivet pin can be passed through each of the second recesses, and wherein the free ends of the second rivet pins are formed into rivet heads, in particular by ultrasonic welding. It is advantageous that a better and more stable spatial fixation of the first connecting elements on the carrier part can be achieved, so that movement of the connecting elements relative to the carrier part is prevented.

[0045] In an advantageous embodiment, the first fastening areas of each of the first interconnection elements each have the same first radial position and / or the same first axial position, and / or the second fastening areas of each of the first interconnection elements each have the same second radial position and / or the same second axial position, in particular wherein the first radial position and the second radial position are different, in particular wherein the first axial position and the second axial position are different.

[0046] An advantage of this is that the spatial fixation of the first interconnection elements on the support part is further improved. Tilting of the interconnection elements relative to the support part is prevented.

[0047] In an advantageous embodiment, the area covered by one of the first interconnection elements in the circumferential and radial directions overlaps two areas covered by two other first interconnection elements in the circumferential and radial directions.

[0048] An advantage of this is that a more compact design of the interconnection unit can be achieved. The wording should be understood to mean that in certain circumferential and radial regions, three initial interconnection elements are arranged axially one above the other.

[0049] In an advantageous embodiment, a second interconnection element is provided which has three, in particular exactly three, contact areas, wherein each of the three contact areas of the second interconnection element is connected to one of the coil terminals, in particular electrically connected, in particular by means of laser welding.

[0050] An advantage of this design is that the coils can be connected in a star point configuration. The second connection element serves as the star point for connecting three different coil terminals. For a delta connection, the second connection element is unnecessary.

[0051] In an advantageous embodiment, the second connecting element has two, in particular exactly two, fastening areas for a positive-locking and / or material-locking connection with the carrier part, in particular wherein each fastening area has a recess extending in the axial direction and wherein a third rivet pin can be passed through each of the recesses, in particular wherein the free ends of the third rivet pins are formed into rivet heads, in particular by means of ultrasonic welding.

[0052] The advantage here is that a better and more stable spatial fixation of the second interconnection element on the carrier part can be achieved, so that movement of the interconnection element relative to the carrier part is prevented.

[0053] In an advantageous embodiment, the area covered in the radial direction by the second interconnection element and the area covered in the radial direction by at least one of the first interconnection elements, in particular by all first interconnection elements, are the same.

[0054] An advantage of this is that space can be saved in the radial direction, so that a compact design of the interconnection unit can be achieved in the radial direction.

[0055] In an advantageous embodiment, the area covered by the second interconnection element in the circumferential and radial direction overlaps with the area covered by at least one of the first interconnection elements, in particular by two of the first interconnection elements, in the circumferential and radial direction.

[0056] An advantage of this is that a compact design for the wiring unit can be achieved.

[0057] In an advantageous embodiment, several, in particular exactly three, third interconnection elements are provided, each of which has a first contact area and a second contact area, which are in particular designed differently, wherein the first contact area of ​​each third interconnection element is connected to one of the coil terminals, in particular electrically connected, in particular by means of laser welding.

[0058] A key advantage is the ease with which the phase conductors, particularly the three, can be connected to the electric motor. The third connection elements are electrically connected to the first contact area, linking them to the coils that are to be connected to each phase. The second contact area is then used to connect the third connection elements to the phase conductors, thus establishing an electrical connection between the phase conductor and the coil. This connection is achieved, for example, by attaching the phase conductor cable lugs to the second mounting area using a screw and nut.

[0059] In an advantageous embodiment, each of the third interconnection elements has a first and a second fastening area for a positive-locking and / or material-locking connection with the carrier part, in particular wherein each of the two fastening areas has a recess extending in the axial direction and wherein a fourth rivet pin can be passed through each of the recesses, in particular wherein the free ends of the fourth rivet pins are formed into rivet heads, in particular by means of ultrasonic welding.

[0060] An advantage of this is that a better and more stable spatial fixation of the third interconnection elements on the carrier part can be achieved, so that movement of the interconnection elements relative to the carrier part is prevented.

[0061] In an advantageous embodiment, each of the third interconnection elements has a third fastening area for a positive-locking and / or material-locking connection with the carrier part, wherein the third fastening area adjoins the first contacting area of ​​the respective third interconnection element, in particular wherein the third fastening area has an axially continuous recess through which a fifth rivet pin can be passed, in particular wherein the free ends of the fifth rivet pins are formed into rivet heads, in particular by means of ultrasonic welding.

[0062] An advantage of this is that the spatial fixation of the third interconnection elements on the carrier part is further improved.

[0063] In an advantageous embodiment, the third interconnection elements are identical in construction.

[0064] The advantage here is that fewer different types of interconnection elements need to be manufactured, thus reducing production costs. The interconnection unit can be manufactured using only one type of third interconnection element.

[0065] In an advantageous embodiment, the carrier part has several guide areas on its outer circumference for guiding the coil connections in the axial direction, wherein each contact area connected to a coil connection is assigned a guide area, in particular wherein the shape of the guide area is essentially the same as the shape of the respective assigned contact area.

[0066] An advantage of this method for manufacturing the electric motor is that the step of contacting the coil terminals with the wiring unit can be carried out more reliably. Guiding the coil terminals ensures that they are essentially parallel to the axis of rotation. The coil terminals can advantageously be clamped to the guide sections, thus facilitating the process step of creating a material-bonded connection between the contact area and the coil terminal. This enables automated manufacturing.

[0067] According to the invention, at least one of the first interconnection elements is such that it is formed by a,

[0068] in particular a prefabricated insulating part made of insulating material, produced by injection molding, such that the surrounded first interconnection element and the surrounding insulating part are positively connected on both sides in the circumferential direction and / or positively connected on both sides in the axial direction and / or positively connected on one side in the radial direction, in particular wherein only every second of the first interconnection elements is surrounded by a respective insulating part in the circumferential direction.

[0069] An advantage of this method is that sufficient electrical insulation between the first interconnection elements is easily achievable. Prefabricated insulating components allow for smaller distances between the first interconnection elements while simultaneously ensuring adequate creepage distances for sufficient electrical insulation. An alternative approach, not part of the invention, would involve subsequently overmolding the first interconnection elements with an insulating material. However, this method is more difficult and expensive to implement.

[0070] In an advantageous embodiment, the coil connections are materially bonded by laser welding to the contacting areas of the first and / or to the contacting areas of the second and / or to each contacting area of ​​the third interconnection elements, in particular wherein the contacting areas to be connected have a V-shaped notch for receiving a coil connection in the form of a winding wire, in particular wherein the V-shaped notch has a circular arc section, in particular wherein the radius of the circular arc section is at most as large as the radius of the winding wire.

[0071] A key advantage of laser welding is that contacting can be carried out so quickly that the initial connection elements do not heat up significantly. This allows the weld points to be located close to insulating materials, especially plastics, without damaging or deforming them through heating. In particular, this makes it possible to position a contact area close to, i.e., adjacent to, a mounting area, resulting in a more compact design.

[0072] The V-shaped notch has the advantage that a secure and reliable electrical connection can always be established for various diameters of winding wires. The wire is always symmetrical to the notch's axis of symmetry and therefore contacts the contact area at at least two points. Thus, one type of contact area can be used for different wire diameters.

[0073] Important features of the invention in the method for manufacturing an electric motor are the successive steps: i) Providing a carrier part, in particular substantially ring-shaped, made of an insulating material, in particular wherein the carrier part is manufactured by injection molding; ii) Arranging several identical first interconnection elements circumferentially on the carrier part, wherein the first interconnection elements each have two, in particular exactly two, contact areas and the first interconnection elements are arranged such that the area covered circumferentially and radially by one of the first interconnection elements overlaps an area covered circumferentially and radially by an adjacent first interconnection element, wherein the first interconnection elements are spaced apart from one another; iii) Connecting the first interconnection elements to the carrier part, in particular by positive locking and / or material locking, to form an interconnection unit; iv) Electrical connection.in particular by means of laser welding, joining of each of the contacting areas of the first interconnection elements to a coil connection of one of several coils, each having two coil connections, which are arranged on a stator of the electric motor, for connecting the coils to a multi-phase winding, . wherein in step ii) the first interconnection elements are arranged such that in the circumferential direction at least one of the first interconnection elements is surrounded by an insulating part made of an insulating material, in particular by injection molding, wherein the surrounded first interconnection element and the surrounding insulating part are positively connected on both sides in the circumferential direction and / or positively connected on both sides in the axial direction and / or positively connected on one side in the radial direction.

[0074] An advantage of this is that a compact design for the wiring unit can be achieved.

[0075] As per the plan, in step ii), the first interconnection elements are arranged such that in the circumferential direction at least one of the first interconnection elements (30, 90), in particular only every second of the first interconnection elements, is formed by a prefabricated component, in particular manufactured by injection molding.

[0076] The insulating part is surrounded by an insulating material, wherein the surrounded first interconnection element and the surrounding insulating part are positively connected on both sides in the circumferential direction and / or positively connected on both sides in the axial direction and / or positively connected on one side in the radial direction.

[0077] An advantage of this method is that sufficient electrical insulation between the first interconnection elements is easily achievable. Prefabricated insulating components allow for smaller distances between the first interconnection elements while simultaneously ensuring adequate creepage distances for sufficient electrical insulation. An alternative approach, not part of the invention, would involve subsequently overmolding the first interconnection elements with an insulating material. However, this method is more difficult and expensive to implement.

[0078] In an advantageous embodiment, particularly in step ii), a second interconnection element is arranged on the carrier part, wherein the second interconnection element has three, in particular exactly three, contact areas. wherein, in particular in step iii), to form the interconnection unit, the second interconnection element is connected to the carrier part, in particular by positive locking and / or by material locking, wherein, in particular in step iv), each of the contacting areas of the second interconnection element is connected to one of the coil terminals, in particular by electrical connection, in particular by material locking using laser welding.

[0079] An advantage of this design is that the coils can be connected in a star point configuration. The second connection element serves as the star point element for connecting three different coil terminals.

[0080] In an advantageous embodiment, particularly in step ii), three third interconnection elements are arranged on the carrier part, wherein the third interconnection elements each have two, in particular different, contact areas, and wherein, particularly in step iii), the third interconnection elements are connected to the carrier part to form the interconnection unit, in particular by a positive locking connection.

[0081] and / or are materially bonded, wherein, in particular in step iv), each of the two contacting areas of the third interconnection elements is connected to each of the coil terminals, in particular electrically connected, in particular materially bonded by means of laser welding.

[0082] A key advantage is the ease with which the phase conductors, particularly the three, can be connected to the electric motor. The third connection element is connected via one of its contact points to the coils that are to be connected to each phase. These coils are then easily connected to the phase conductors, for example, using cable lugs.

[0083] In an advantageous embodiment, particularly according to step iv), the stator with coils and the interconnection unit connected to the coil terminals are potted with potting compound, in particular such that the contacting areas of the third interconnection elements, which are not connected to a coil terminal, remain free of potting compound.

[0084] An advantage of this is that a stable mechanical fixation of the interconnection unit on the stator is achievable.

[0085] Further advantages arise from the sub-claims.

[0086] The invention will now be explained in more detail with the help of illustrations: In the Figure 1 Figure 1 shows a first embodiment of a circuit unit arranged on a stator of an electric motor according to the invention in a perspective view. Figure 2A is the stator and the first embodiment of the interconnection unit made of Figure 1 shown in a side view. In the Figure 2B is the stator and the first embodiment of the interconnection unit made of Figure 1 shown in a top view. In the Figure 3A is a first interconnection element of the first embodiment of the interconnection unit made of Figure 1 shown in a perspective view. In the Figure 3B is the first interconnection element of the Figure 3A shown in a side view. In the Figure 3Cis a projection in the axial direction onto a plane perpendicular to the axis of rotation of the first interconnection element from the Figures 3A and 3B shown. In the Figure 4 is a second interconnection element of the first embodiment of the interconnection unit made of Figure 1 shown in a perspective view. In the Figure 5A is a third interconnection element of the first embodiment of the interconnection unit made of Figure 1 shown in a perspective view. In the Figure 5B is the third interconnection element made of Figure 5A shown in a top view. In the Figure 6 is the carrier part of the first embodiment of the interconnection unit made of Figure 1 with the second interconnection element arranged on it made of Figure 4 shown in a perspective view. In the Figure 7A is the first interconnection element made of Figure 3A shown in a perspective view with an attached insulating section. In the Figure 7BThe first two wiring elements are shown in a perspective view. In the Figure 7C is a projection in the axial direction onto a plane perpendicular to the axis of rotation of the two first interconnection elements from Figure 7B shown. In the Figure 8 is the carrier part of the first embodiment of the interconnection unit made of Figure 1 shown in a perspective view with the connecting elements arranged on it. In the Figure 9A An insulating part of the second embodiment of the wiring unit is shown in a perspective view. In the Figure 9B A first interconnection element of the second embodiment of the interconnection unit is shown in a perspective view. In the Figure 9C is the insulating part made of Figure 9A together with the first interconnection element from Figure 9B shown in a perspective view. In the Figure 9D are the insulating part and the first interconnection element made of Figure 9Cand another initial wiring element shown in a perspective view. In the Figure 10 A wiring unit of the second embodiment is shown in a perspective view.

[0087] Exemplary embodiments of the invention are explained below with reference to the accompanying drawings, whereby the same reference numerals are used for parts that act identically and are not described again with each figure.

[0088] Figure 1Figure 1 shows a perspective view of a first embodiment of a circuit unit 1, which is arranged at an axial end of a stator 2 of an electric motor according to the invention (not shown in further detail). The stator 2 of the electric motor is constructed from individual stator segments 3. In the illustrated embodiment, the stator 2 has twelve stator segments 3. The number twelve is only exemplary; other numbers of stator segments are also conceivable. In this embodiment, the stator segments 3 are preferably designed as stamped laminated cores.

[0089] The stator segments 3 are connected to each other to form a substantially cylindrical stator 2. A rotor (not shown) is arranged inside the stator 3 and is rotatably mounted about an axis of rotation D. The rotor and stator 2 are arranged concentrically to the axis of rotation D. The rotor preferably has permanent magnets, and the electric motor is preferably designed as a permanent magnet synchronous motor.

[0090] Each stator segment 3 has a stator tooth around which a coil 4 is wound. The coil is formed from insulated winding wire. The two ends of the winding wire are stripped and form the two coil terminals 5, 6. The coils 4 are in Figure 1 This is only a schematic representation. For example, insulating paper 7 is located between the coils 4 and the stator segments 3 for electrical insulation.

[0091] Figure 2A shows the arrangement Figure 1in a side view. The direction A, which runs parallel to the axis of rotation D, is called the axial direction. Figure 2B shows the arrangement Figure 1 in a top view. The radial direction R is defined as shown, starting from the axis of rotation D. The radial direction R is therefore perpendicular to the axial direction A. The circumferential direction U runs along the circumference of the stator 2 and is also shown in Figure 2B shown.

[0092] The individual coils 4 are connected to form a multi-phase winding by means of the connection unit 1. In the present embodiment, the twelve coils 4 are connected to each other in a star connection, forming a three-phase winding. Each phase is therefore assigned four individual coils 4. Within a phase, the four coils 4 are connected in series by means of the connection unit 1. All three phases are connected to each other at the star point. The individual elements of the connection unit 1 are explained in the following figures for clarity.

[0093] The interconnection unit 1 according to the invention comprises several interconnection elements 30, 40, 50 for connecting the coil terminals and a carrier part 60 for receiving the interconnection elements 30, 40, 50. To connect the twelve coils 4 shown in this exemplary embodiment to a three-phase winding in a star connection, nine first interconnection elements 30 and one second interconnection element 40 are required. If n denotes the number of phases and z the number of stator segments 3 and, accordingly, the number of coils 4, then for a star connection (z - n) first interconnection elements 30 and one second interconnection element 40 are necessary. The second interconnection element 40 is therefore only necessary for a star connection. For other types of connection, for example delta connection, it is dispensable.

[0094] Figure 3AFigure 1 shows a first interconnection element 30 in perspective view. The first interconnection element 30 is made of sheet metal, preferably sheet steel or copper, and is preferably manufactured as a stamped and bent part. In the present embodiment, the first interconnection element 30 comprises a first contact area 31 and a second contact area 32. The two contact areas 31, 32 are spaced apart from each other. A connecting area 33 is arranged between the two contact areas 31, 32. The connecting area 33 connects the two contact areas 31, 32. The contact areas 31, 32 serve for the electrical and mechanical connection of the first interconnection element 30 to the coil terminals 5, 6. Each contact area 31, 32 is connected to one coil terminal 5, 6.The contact areas 31, 32 have a V-shaped notch 301 for receiving a coil connection 5, 6 in the form of a winding wire.

[0095] In addition to the contact areas 31, 32, the first interconnection element 30 comprises a first mounting area 34 and a second mounting area 35. The mounting areas 34, 35 serve to fasten the first interconnection element 30 to the carrier part 60. In the present embodiment, the mounting areas 34, 35 each have a through recess 36, 37 in the form of a cylindrical hole. Alternatively, semi-open recesses, for example in the form of an axially extending groove, are also possible.

[0096] Figure 3B The first interconnection element 30 is shown. Figure 3Ain a side view. In the present embodiment, the first connecting element has a first stage 37 and a second stage 38. These stages 37, 38 are preferably produced by bending. Due to these stages 37, 38, the first and second fastening areas 34, 35 have different axial positions.

[0097] Figure 3C shows a vertical projection of the first interconnection element 30 from Figure 3A onto a plane perpendicular to the axis of rotation. Steps 38 and 39 from Figure 3B are therefore not visible. The hatched area B1 shows the area covered by connection area 33 in the circumferential and radial directions.

[0098] Figure 4Figure 1 shows a second interconnection element 40 in perspective view. The second interconnection element 40 is made of sheet metal, preferably steel or copper, and is preferably manufactured as a stamped and bent part. In the present embodiment, the second interconnection element 40 comprises a first contact area 41, a second contact area 42, and a third contact area 43. The three contact areas 41, 42, 43 are spaced apart from one another. A connecting area 44 is arranged between the first contact area 41 and the third contact area 43. The second contact area 42 is also arranged at the connecting area 44. The connecting area 44 thus connects the three contact areas 41, 42, 43 to one another. The contact areas 41, 42, 43 serve for the electrical and mechanical connection of the second interconnection element 40 to the coil terminals 5, 6.Each contact area 41, 42, 43 is connected to a coil terminal 5, 6. The contact areas 41, 42, 43 have a V-shaped notch 401 for receiving a coil terminal in the form of a winding wire. In a three-phase connection in a star configuration, the second connection element 40 forms the star point where the three phases are connected.

[0099] In addition to the contact areas 41, 42, 43, the second interconnection element 40 comprises a first mounting area 45 and a second mounting area 46. The mounting areas 45, 46 serve to fasten the second interconnection element 40 to the carrier part 60. In the present embodiment, the mounting areas 45, 46 each have a through recess 47 in the form of a cylindrical hole. Alternatively, semi-open recesses, for example in the form of an axially extending groove, are also possible.

[0100] Figure 5AFigure 1 shows a third interconnection element 50 in perspective view. The third interconnection element 50 is made of sheet metal, preferably steel or copper, and is preferably manufactured as a stamped and bent part. In the present embodiment, the third interconnection element 50 comprises a first contact area 51 and a second contact area 52. The two contact areas 51 and 52 are spaced apart from each other. The first contact area 51 serves for the electrical and mechanical connection of the third interconnection element 50 to a coil terminal 5 or 6 and has a V-shaped notch 501 for this purpose. The second contact area 52 serves for the electrical and mechanical connection of the third interconnection element 50 to a phase conductor. The third interconnection elements 50 thus form the connections of the electric motor to the phases U, V, and W.Therefore, three third-phase connection elements 50 are required for a three-phase winding. The connection between the third-phase elements...

[0101] The connection between the terminal elements 50 and the phase conductors can be made directly or indirectly via a screw 80 with a corresponding nut 81. In principle, a direct connection between the phase conductors and the coil terminals 5, 6 can also be established, making the third terminal elements 50 unnecessary. However, the third terminal elements 50 simplify the manufacturing process of the electric motor and facilitate the connection of the phase conductors to the electric motor. In the present embodiment, the second contact area 52 has a continuous recess. A screw 80 is passed through this recess, serving as a connection for a cable lug of the phase conductor. A nut 81 is used to fasten the cable lug to the third terminal element.

[0102] In addition to the contact areas 51, 52, the third interconnection element 50 comprises a first mounting area 53, a second mounting area 54, and a third mounting area 55. The mounting areas 53, 54, 55 serve to fasten the third interconnection element 50 to the carrier part 60. In the present embodiment, the mounting areas 53, 54, 55 have semi-open recesses 56, 57 in the form of axially extending grooves. Alternatively, closed recesses, for example in the form of cylindrical holes, are also possible.

[0103] Figure 6Figure 60 shows the support part 60 with a second interconnection element 40 mounted on it. The support part 60 is essentially ring-shaped and, in this embodiment, is manufactured as an injection-molded plastic part. It is preferably manufactured in one piece. The support part 60 is mounted concentrically to the axis of rotation D at an axial end of the stator 2, as shown in Figure 2. Figure 1 The support part 60 has axial extensions 61, 62, 63, 64, 65 in the form of rivet pins. In this embodiment, the extensions 61, 62, 63, 64, 65 are cylindrical, but other shapes are also conceivable. The rivet pins 61, 62, 63, 64, 65 are preferably designed to complement the corresponding recesses 36, 37, 47, 56, 57 in order to enable a stable mechanical connection between the support part 60 and the connecting element 30, 40, 50.

[0104] The support part 60 has first rivet pins 61 and second rivet pins 62 for holding the first connecting element 30. Preferably, the support part 60 has third rivet pins 63 for holding the second connecting element 40. Preferably, the support part 60 has fourth rivet pins 64 and fifth rivet pins 65 for holding the third connecting elements 50.

[0105] The first, third and fourth rivet pins are advantageously arranged close to the inner circumference of the support part 60, while the second and fifth rivet pins are arranged close to the outer circumference of the support part 60.

[0106] Distributed around the outer circumference of the carrier part 60, this part has several guide areas 66. Each guide area 66 has a V-shaped groove and serves to guide the coil terminals 5, 6 in the axial direction during the establishment of the electrical connection between the coil terminals 5, 6 and the contact areas 31, 32, 41, 42, 43, 51. For this purpose, the position of a guide area 66 in the radial and circumferential directions is essentially the same as the position of a corresponding contact area 31, 32, 41, 42, 43, 51. A guide area 66 is arranged axially below a contact area 31, 32, 41, 42, 43, 51. The V-shaped indentation of the guide area 66 is slightly offset in the radial direction, for example by 0.5 mm, towards the inner circumferential side, so that good contact between coil connection 5,6 and contact area 31, 32, 41, 42, 43, 51 is ensured.

[0107] During the manufacturing process, the coil terminals 5, 6 are first bent so that they point radially outwards. The interconnection unit 1 is then placed on the stator 2, and the coil terminals 5, 6 are subsequently bent into position so that they point axially upwards and contact the corresponding contact areas 31, 32, 41, 42, 43, 51. The guide areas 66 assist in this contacting process, ensuring that the coil terminals 5, 6 are essentially parallel to the axial direction A.

[0108] The starting point for the method of manufacturing the interconnection unit 1 is the carrier part 60 made of insulating material. In the present embodiment, this is manufactured from plastic using an injection molding process. Then, as described in Figure 6The second connecting element 40 is shown arranged on the support part 60. The continuous recesses 47 of the fastening areas 45, 46 of the second connecting element 40 serve for retention, so that the third rivet pins 63 can be inserted through the recesses 47.

[0109] In a subsequent manufacturing step, the first interconnection elements 30 are arranged on the carrier part 60 such that the area (B1, B2) covered in the circumferential and radial directions by the connection area 33 of one of the first interconnection elements 30 overlaps an area (B1, B2) covered in the circumferential and radial directions by the connection area 33 of another of the first interconnection elements 30. In other words, the first interconnection elements are at least partially stacked axially on top of each other in the circumferential direction, thus enabling a more compact design.

[0110] The through recesses 36, 37 of the fastening areas 34, 35 of the first fastening elements 30 serve to hold the first fastening elements 30, allowing the first and second rivet pins 61, 62 to pass through the recesses 36, 37. Because one of the two recesses 36, 37 of a first fastening element 30 is arranged radially further inward than the other recess 37, stable retention is ensured. In particular, tilting of the first fastening elements 30 is prevented. In other words, the first fastening areas 34 have a radial position that differs from the radial position of the second fastening areas 35.

[0111] The first and second rivet pins 61, 62 and the first interconnection elements 30 are arranged and shaped such that the first interconnection elements 30 do not touch each other. They are therefore spaced apart from one another. In principle, this means that in a non-inventive embodiment, no further electrical insulation is necessary, since the stator is usually potted with a potting compound in a final manufacturing step, which serves as an insulating material.

[0112] According to the invention, electrical insulation between the first interconnection elements 30 is achieved by means of prefabricated insulating parts. For this purpose, insulating parts 70 are manufactured from plastic, for example, by injection molding. Figure 7AFigure 1 shows an insulating part 70 that partially surrounds a first connection element. In this embodiment, the insulating part 70 is shaped such that it can be slid onto the first connection element 30 in a radial direction. The first connection element 30 is partially surrounded by the insulating part 70 in the circumferential direction such that relative movement of the insulating part 70 and the first connection element 30 in this direction is not possible. Thus, a positive-locking connection is present on both sides in the circumferential direction. Furthermore, the first connection element 30 is partially surrounded by the insulating part 70 in the axial direction such that relative movement of the insulating part 70 and the first connection element 30 in this direction is not possible. Thus, a positive-locking connection is present on both sides in the axial direction.In the radial direction, the first interconnection element 30 is only positively connected to the insulating part 70 on one side, so that a displacement against each other is possible.

[0113] It is advantageously possible that, in the circumferential direction, only every second of the first interconnection elements 30 is surrounded by an insulating part 70 as described above. Figure 7B shows the first interconnection element 30A with the insulating part 70 pushed on. Figure 7A and additionally another first connection element 30B, which is simply placed on the insulating part 70. A further first connection element 30, surrounded by an insulating part 70, is then placed on this further first connection element 30B.

[0114] Figure 7CFigure 7BA shows a vertical projection of the first two interconnection elements 30A, 30B from Figure 7BA onto a plane perpendicular to the axis of rotation. The insulating part 70 is not shown here. The hatched area B1 shows, as in Figure 7BA, the connection between the two interconnection elements 30A and 30B from Figure 7BA and the axis of rotation. The insulating part 70 is not shown here. The hatched area B1 shows the connection as shown in Figure 7BA. Figure 3C The area covered by the connection area 33 of a first interconnection element 30 in the circumferential and radial directions is shown. Similarly, the hatched area B2 indicates the area covered by the connection area 33 of the other first interconnection element 30B in the circumferential and radial directions. These two areas partially overlap. In this embodiment, the areas covered by the two connection areas 33 in the radial direction are the same. However, it is also possible for them to be different.

[0115] Figure 8 shows the carrier part 60 and the second interconnection element 40. Figure 6with the nine first interconnection elements 30 arranged thereon and the insulating parts 70 arranged between them. Since only every second interconnection element 30 is surrounded by an insulating part 70, only five insulating parts 70 are necessary in this embodiment. Additionally, in Figure 8A third connection element 50 is shown, which is held by two fourth rivet pins 64 and a fifth rivet pin 65 of the support part 60. A square screw 80 with a corresponding nut 81 serves to connect the third connection element 50 to the phase conductor. The head of the screw is arranged axially below the continuous recess of the second mounting area 52, so that the hexagonal nut 81 is accessible from above. This allows for easy contact of the phase conductor with the third connection element 50, for example, by means of cable lugs. In addition to the third connection element 50 shown, two further third connection elements 50 are used in this embodiment, which are placed circumferentially counterclockwise next to the third connection element 50 shown. Figure 1 All three third interconnection elements 50 are shown.

[0116] After all the connecting elements 30, 40, 50 are arranged on the carrier part 60, they are connected to the carrier part 60. In this example, the free ends of the rivet pins 61, 62, 63, 64, 65 are formed into rivet heads such that the diameter of the rivet heads in the plane perpendicular to the axis of rotation is larger than the diameter of the corresponding recesses. This forming can be carried out, for example, by ultrasonic welding, hot riveting, or hot stamping. If only the rivet pin is formed during the forming process, without creating a material bond between the carrier part and the connecting elements, a positive-locking connection is established. However, it is also conceivable that a material bond between the carrier part and the connecting elements is created alternatively or additionally.

[0117] After the interconnection elements 30, 40, 50 are connected to the carrier part 60, the coil terminals 5, 6 are connected to the corresponding contact areas 31, 32, 41, 42, 51 of the interconnection elements 30, 40, 50 to establish an electrical connection. For this purpose, the stripped wire ends of the coils are inserted into the V-shaped notches 301, 401, 501 of the contact areas 31, 32, 41, 42, 51, and a metallurgical bond is established between the wire and the interconnection element. In this embodiment, this is done by laser welding. However, other methods are also possible.

[0118] After the coils 4 of the electric motor have been connected in this way to form a multi-phase winding by means of the connection unit 1, the stator 2, together with the connection unit 1 arranged at one axial end of the stator, is potted with potting compound for mechanical fixation. If, in a non-inventive variant, no insulating parts 70 are used, this potting compound serves as electrical insulation between the connection elements 30, 40, 50.

[0119] If, as shown in the present embodiment, three third interconnection elements 50 are used, care must be taken during potting to ensure that the second mounting areas 54 of the third interconnection elements 50 remain free of potting compound. To ensure that the third interconnection elements 50 are sufficiently encased by the potting compound and a stable hold is achieved, the third interconnection elements 50 advantageously have anchor areas 58 which point axially from the third mounting area towards the stator 2. For better anchoring in the potting compound, the anchor area 58 advantageously has an undercut 59.

[0120] Figure 9BAlternatively, Figure 1 shows a first interconnection element 90 for a second embodiment of a connecting unit 1. This first interconnection element 90 also has a first contact area 91 and a second contact area 92. The contact areas 91, 92 each comprise a retaining arm 93, with which a respective coil connection 5, 6 can be retained and held securely, in particular clamped between the retaining arms. In addition, the coil connections 5, 6 are preferably metallurgically bonded to the retaining arms by means of contact welding. The retaining arms 93 are V-shaped, with the retaining arms forming the legs of the V.

[0121] The grasping arms 93 enable a quick and simple electrical connection of the coil terminals 5, 6 to the contacting areas 91, 92. This occurs when the circuit unit 1 is rotated relative to the stator 2. As the coil terminals 5, 6 are captured within the inner area enclosed by the contacting areas 91, 92, specifically within the inner area enclosed by the V of the V-shaped grasping arm 93. The respective contacting area 91, 92 thus threads the respective coil terminal 5, 6 into the connection position at the inner apex of the V. Once the rotation is complete, a contact welding connection is performed. For this purpose, the respective legs of the contacting area 91, 92, i.e., grasping arms 93, are first pressed together by bending them accordingly until the coil connection 5, 6 is held securely, in particular clamped, by the grasping arms 93 of the contacting area 91, 92.Then contact welding is carried out so that the electrical connection between coil terminal 5,6 and contacting area 91, 92 can be made without solder.

[0122] As in the first embodiment, the connection area 94 of the first interconnection element 90 of the second embodiment has two axial steps 95, 96.

[0123] In contrast to the first embodiment, this first connecting element 90 has only one fastening area 97. The fastening area has a continuous recess 98.

[0124] Figure 9A shows an insulating part 99 which is pushed onto the first interconnection element 90. Figure 9C shows the first interconnection element 90 with the insulating part 99 pushed onto it.

[0125] Figure 9D shows the first interconnection element 90A with the insulating part 99 pushed on. Figure 9Cand additionally a further first interconnection element 90B, which is arranged on the insulating part 99. The areas covered by the two connection areas 94 of the two first interconnection elements 90A, 90B overlap in the circumferential and radial directions.

[0126] Figure 10 Figure 1 shows the interconnection unit 100 of the second embodiment. As in the first embodiment, the interconnection unit 100 has a support part 101 for holding the nine first interconnection elements 90, the second interconnection element 102 and the three third interconnection elements 103.

[0127] As in the first embodiment, the second interconnection element 102 has three contact areas 104. As in the first embodiment, the second interconnection element 102 has two mounting areas 105, of which only one is visible due to the perspective view.

[0128] As in the first embodiment, the third interconnection element 103 has a first contact area 106 for contacting a coil terminal 5, 6 and a second contact area 107 for contacting a phase conductor. In contrast to the first embodiment, the third interconnection element 103 has only one mounting area 108.

[0129] The positive locking connection between the connecting elements 90, 102, 103 and the support part 101 is also achieved in the second embodiment by forming rivet pins of the support part, which can be passed through recesses in the respective fastening areas, into rivet heads.

[0130] In the second embodiment, the positioning of the interconnection elements 90, 102, 103 on the carrier part 101 is achieved by the carrier part 101 having a circumferential annular groove for receiving the interconnection elements 90, 102, 103. Furthermore, the carrier part 101 has recesses 109 in the groove wall on its outer circumference, through which the contact areas 91, 92, 104, 106 can be passed. This also contributes to the precise positioning of the components.

[0131] In both embodiments, all first interconnection elements 30, 90 are identical in construction, i.e., they are identical parts. Likewise, the third interconnection elements 50, 103 are also identical in construction, i.e., they are identical parts. This has the advantage that the parts can be manufactured more cheaply. However, it is also possible for the first interconnection elements 30, 90 and / or the third interconnection elements 50, 103 to be designed differently.

[0132] In both embodiments, the axially covered areas and the radially covered areas of the first interconnection elements 30, 90 are the same. However, it is also possible for these areas to differ. Reference symbol list

[0133] 1 Interconnection unit 2 Stator 3 Stator segment 4 Coil 5 First coil connection 6 Second coil connection 7 Insulating paper 30 First interconnection element 31 First contact area of ​​a first interconnection element 32 Second contact area of ​​a first interconnection element 33 Connection area of ​​a first interconnection element 34 First mounting area of ​​a first interconnection element 35 Second mounting area of ​​a first interconnection element 36 First through-hole in a first interconnection element 37 Second through-hole in a first interconnection element 38 First stage of a first interconnection element 39 Second stage of a first interconnection element 301 V-shaped notch 40 Second interconnection element 41 First contact area of ​​the second interconnection element 42 Second contact area of ​​the second interconnection element 43 Third contact area of ​​the second interconnection element 44Connection area of ​​the secondInterconnecting element 45 First fastening area of ​​the second interconnecting element 46 Second fastening area of ​​the second interconnecting element 47 Through-hole in the second interconnecting element 401 V-shaped notch 50 Third interconnecting element 51 First contact area of ​​a third interconnecting element 52 Second contact area of ​​a third interconnecting element 53 First fastening area of ​​a third interconnecting element 54 Second fastening area of ​​a third interconnecting element 55 Third fastening area of ​​a third interconnecting element 56 Through-hole in a third interconnecting element 57 Through-hole in a third interconnecting element 58 Anchor area of ​​a third interconnecting element 60 Carrier part 61 First rivet pin 62 Second rivet pin 63 Third rivet pin 64 Fourth rivet pin 65 Fifth rivet pin 66 Guide area 70 Insulated part 80 Screw 81 Nut 90 First wiring element 91 First contact area92 Second contact area of ​​a first connection element 93 Catch arm 94 Connection area of ​​a first connection element 95 Axial step 96 Axial step 97 Mounting area of ​​a first connection element 98 Through-hole in a first connection element 99 Insulated part 100 Connection unit 101 Support part 102 Second connection element 103 Third connection element 104 Contact area of ​​a second connection element 105 Mounting area of ​​a second connection element 106 First contact area of ​​a third connection element 107 Second contact area of ​​a third connection element 108 Mounting area of ​​a third connection element

Claims

1. Electric motor comprising a rotor which is arranged so as to be rotatable about an axis of rotation (D), and comprising a stator (2), the stator (2) having a plurality of coils (4), each coil (4) having two coil terminals (5, 6), the coils being interconnected by means of an interconnection unit (1, 100), the interconnection unit (1, 100) comprising a support part (60, 101) made of an insulating material for bearing a plurality of spaced-apart interconnection elements (30, 40, 50, 90, 102, 103), at least three first interconnection elements (30, 90) being provided, each of the first interconnection elements (30, 90) in each case having two spaced-apart contact regions (31, 32, 91, 92) and one connection region (33, 94) that is connected to the contact regions (31, 32, 91, 92), the contact regions (31, 32, 91, 92) of each first interconnection element (30, 90) each being electrically connected to one of the coil terminals (5, 6) at one connection point (20) each, a region (B1, B2) that is covered by the connection region (33, 94) of one of the first interconnection elements (30, 90) in the circumferential direction (U) and the radial direction (R) overlapping in each case with a region (B1, B2) that is covered by the connection region (33, 94) of another of the first interconnection elements (30, 90) in the circumferential direction (U) and the radial direction (R), the first interconnection elements (30, 90) being configured to be structurally identical, characterised in that at least one of the first interconnection elements (30, 90) is enclosed by a prefabricated insulating part (70, 99) made of insulating material in such a way that the enclosed first interconnection element (30, 90) and the enclosing insulating part (70, 99) are interlockingly connected on both sides in the circumferential direction (U) and / or are interlockingly connected on both sides in the axial direction (A) and / or are interlockingly connected on one side in the radial direction (R).

2. Electric motor according to claim 1, characterised in that the insulating part (70, 99) is manufactured by means of an injection moulding method.

3. Electric motor according to claim 1 or claim 2, characterised in that in the circumferential direction (U), only every other first interconnection element (30, 90) is enclosed thus by a particular insulating part (70, 99).

4. Electric motor according to any of the preceding claims, characterised in that the connection region (33, 94) of each of the first interconnection elements (30, 90) has an in particular approximately rectangular cross section, the extent thereof in the axial direction being less than the extent thereof in the radial direction.

5. Electric motor according to any of the preceding claims, characterised in that all the connection regions (33, 94) of the first interconnection elements (30, 90) each have two axial steps (38, 39, 95, 96).

6. Electric motor according to any of claims 1 to 4, characterised in that all the connection regions (33, 94) of the first interconnection elements (30, 90) each have a slope running, in particular constantly, in the axial direction.

7. Electric motor according to any of the preceding claims, characterised in that the two contact regions of each first interconnection element (30, 90) each have different axial positions.

8. Electric motor according to any of the preceding claims, characterised in that each of the first interconnection elements (30, 90) each has a first fastening region (34, 97) for being connected to the support part (60, 101) in an interlocking and / or integrally bonded manner, each of the first interconnection elements (30) each having a second fastening region (35) for being connected to the support part (60) in an interlocking and / or integrally bonded manner, the first fastening regions (34, 97) of each of the first interconnection elements (30, 90) each having the same first axial position, and the second fastening regions (35) of each of the first interconnection elements (30) each having the same second axial position, the first axial position and the second axial position being different.

9. Electric motor according to any of the preceding claims, characterised in that a second interconnection element (40, 105) is provided and has three, in particular exactly three, contact regions (41, 42, 43, 104), each of the three contact regions (41, 42, 43, 104) of the second interconnection element (40, 102) each being electrically connected to one of the coil terminals (5, 6), the second interconnection element (40, 105) in particular having two, in particular exactly two, fastening regions (45, 46, 105) for being connected to the support part (60, 101) in an interlocking and / or integrally bonded manner.

10. Electric motor according to any of the preceding claims, characterised in that exactly three third interconnection elements (50, 103) are provided and each have a first contact region (51, 106) and a second contact region (52, 107), which are configured differently, the first contact region (51, 106) of each third interconnection element (50, 103) being electrically connected to one of the coil terminals (5, 6), each of the third interconnection elements (50) having a first and a second fastening region (53, 54) for being connected to the support part (60) in an interlocking and / or integrally bonded manner, the third interconnection elements (50, 103) in particular being configured to be structurally identical.

11. Electric motor according to any of the preceding claims, characterised in that the support part (60) has, on its outer circumference, a plurality of guide regions (66) for guiding the coil terminals (5, 6) in the axial direction (A), a guide region (64) being assigned in each case to each contact region (31, 32, 41, 42, 43, 51) connected to a coil terminal (5, 6), the shape of the guide region (66) in particular being substantially the same shape as the relevant assigned contact region (31, 32, 41, 42, 43, 51).

12. Electric motor according to at least one of the preceding claims, characterised in that the coil terminals (5, 6) are integrally bonded to the contact regions (31, 32) of the first interconnection elements (30) by means of laser welding, the contact regions (31, 32, 41, 42, 43, 51) that are to be connected having a V-shaped notch (301, 401, 501) for bearing a coil terminal (5, 6), the radius of the circular arc portion being at most the same size as the radius of the winding wire.

13. Method for producing an electric motor according to any of the preceding claims, comprising the following successive steps: i) providing a support part (60, 101) which is in particular substantially annular and is made of an insulating material, the support part (60, 101) in particular being manufactured by means of an injection moulding method, ii) arranging a plurality of structurally identical first interconnection elements (30, 90) in the circumferential direction (U) on the support part (60, 101), the first interconnection elements (30, 90) each having two contact regions (31, 32, 91, 92) and the first interconnection elements (30, 90) being arranged such that the region (B1, B2) covered by one of the first interconnection elements (30) in the circumferential direction (U) and the radial direction (R) in each case overlaps with a region (B1, B2) covered by an adjacent first interconnection element (30, 90) in the circumferential direction (U) and the radial direction (R), the first interconnection elements (30, 90) being arranged at a distance from one another, iii) connecting the first interconnection elements (30, 90) to the support part (60, 101), in particular in an interlocking and / or integrally bonded manner, to form an interconnection unit (1, 100), iv) electrically connecting, in particular integrally bonding by means of laser welding, each contact region (31, 32, 91, 92) of the first interconnection elements (30, 90) in each case to one coil terminal (5, 6) of one of a plurality of coils (4), which each have two coil terminals (5, 6) and are arranged on a stator (2) of the electric motor, in order to interconnect the coils (4) to form a multi-phase winding, characterised in that the first interconnection elements (30, 90) are arranged in step ii) such that at least one of the first interconnection elements (30, 90) is enclosed in the circumferential direction (U) by a prefabricated insulating part (70, 99) which is made of an insulating material and in particular manufactured by means of an injection moulding method, the enclosed first interconnection element (30, 90) and the enclosing insulating part (70, 99) being interlockingly connected on both sides in the circumferential direction (U) and / or being interlockingly connected on both sides in the axial direction (A) and / or being interlockingly connected on one side in the radial direction (R).

14. Method according to claim 13, characterised in that in step ii), a second interconnection element (40, 102) is arranged on the support part (60, 101), the second interconnection element (40, 102) having three, in particular exactly three, contact regions (41, 42, 43, 104), the second interconnection element (40, 102) being connected to the support part (60, 101), in particular in an interlocking and / or integrally bonded manner, in order to form the interconnection unit (1, 100), each of the contact regions (41, 42, 43, 104) of the second interconnection element each being electrically connected to one of the coil terminals (5, 6) in step iv).

15. Method according to claim 13 or claim 14, characterised in that in step ii), exactly three third interconnection elements (50, 103) are arranged on the support part (60, 101), the third interconnection elements (50, 103) each having two different contact regions (51, 52, 106, 107), the third interconnection elements (50, 103) being electrically connected to the support part (60, 101) in order to form the interconnection unit (1, 100), one of the two contact regions (51, 52, 106, 107) of the third interconnection elements (50, 103) each being electrically connected to one of the coil terminals (5, 6) in step iv), the stator (2), which comprises coils (4), and the interconnection unit (1) connected to the coil terminals (5, 6) being encapsulated with casting compound after step iv), in particular in such a way that those contact regions (52) of each third interconnection element (50) which are not connected to a coil terminal (5, 6) remain free of casting compound.