Belt ladder device
The tape conductor device addresses manufacturing inefficiencies and losses in electrical machines by using layered ribbon conductors with smooth position exchanges and optimized geometry, enhancing productivity and reducing electrical losses.
Patent Information
- Authority / Receiving Office
- DE · DE
- Patent Type
- Applications
- Current Assignee / Owner
- ADDITIVE DRIVES GMBH
- Filing Date
- 2025-01-27
- Publication Date
- 2026-06-18
AI Technical Summary
Existing manufacturing processes for conductor structures in electrical machines are time-consuming and hinder mass production, while also leading to high losses due to the skin effect and reduced fill factors.
A tape conductor device with elongated, rigid ribbon conductor elements forming a layered arrangement with electrical insulation, where the elements exchange positions without twisting through material forming, achieving smooth step transitions and minimizing cross-sectional area variations to reduce resistance heat and eddy current losses.
The solution enhances manufacturing efficiency and reduces electrical losses, particularly at higher frequencies, while maintaining a high fill factor and minimizing space usage in electrical machines.
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Abstract
Description
[0001] The invention relates to a ribbon conductor device designed for use in alternating current supplied electrical machines, in particular motors, comprising at least two elongated, in particular rigid, ribbon conductor elements with contact devices for coupling in and out of electric current, wherein the ribbon conductor elements provide a current path and the ribbon conductor elements form a layer arrangement with electrical insulation located between them, according to the preamble of claim 1.
[0002] It is known that so-called Röbel conductors are used in high-current applications in generators or in high-performance electric motors.
[0003] Röbel conductors or Röbel rods typically consist of several individual conductors arranged along the conductor length over a full transposition length (for the term full transposition length, see in particular DE 10 2012 218 986 A1, Fig. 1 and Fig. 2, “V”, and the associated description) exchange their positions once (so that each individual conductor is back in its original position after the exchange – only further along the length of the Röbel conductor). This causes each partial conductor in a wound coil to change its position. This is particularly important with regard to minimizing AC losses and reducing coupling losses. A Röbel conductor typically spans a very large number of full transposition lengths and, due to the large number of Röbel-wound individual conductors, is capable of carrying high currents.
[0004] When winding round coils, the constant swapping of the positions of the individual conductors along the conductor length ensures that a conductor runs temporarily on the inside, i.e., with a smaller winding radius, and then again on the outside, i.e., with a larger winding radius.
[0005] DE 39 23 310 C1 shows an exemplary process for the production of Röbel rods.
[0006] Röbel bars are bars produced by twisting square profile wires. The profile wires can be brought together in the Röbel tool in such a way that sections with untwisted, parallel profile wires and sections with twisted profile wires are continuously arranged next to each other, and that the foremost strand section in the untwisted area is periodically cut off from the strand as a Röbel bar.
[0007] From DE 197 54943 A1, a double Röbel wire for the winding of an electric machine is known. There, conductor sub-conductors are arranged in four adjacent stacks. Two adjacent sub-conductors are arranged as sub-conductor pairs side by side over the entire length of a conductor and are twisted together. To achieve the desired twist, the sub-conductors are bent both parallel and crossed to ensure optimal compensation of the transverse and radial fields of an operating electric machine.
[0008] CH 15177 A discloses a device for manufacturing interlocked flat conductors. In the slots of the stator bars of an alternating current machine, stacked rods of a coil are arranged from several interlocked flat conductors. Free rod ends extend axially from the groove to the base of end connections.
[0009] WO 2022 / 029008 A1, filed by the applicant, relates to a method for the additive manufacturing of a three-dimensional component with at least one electrical conductor, in particular with at least one conductor winding, preferably a coil, preferably a hairpin for an electrical machine, especially an electric motor or generator. The electrical conductor is realized by layer-by-layer application of a build material and locally selective solidification of the build material by irradiation with a beam incident on the build material, such that the conductor comprises first regions and at least one second region, wherein the first regions are at least partially separated in a cross-section perpendicular to the longitudinal direction of the conductor by the at least one second region. The at least one second region has a lower conductivity than the first regions.
[0010] The areas with different conductivity allow structures to be easily created during additive manufacturing that positively influence the current flow, in particular reducing eddy current effects.
[0011] However, it has been shown that, in addition to the many advantages of additive manufacturing of conductor structures, the manufacturing process is very time-consuming, which hinders mass production or an increase in productivity in the production of such windings or coils.
[0012] Based on the foregoing, the object of the invention is to provide, starting from the closest teaching according to WO 2024 / 121095 A1, a further developed tape conductor device designed for use in alternating current supplied electrical machines, in particular electric motors. The tape conductor device should be cost-effective and manufacturable with high efficiency and, moreover, exhibit further improved electrical properties compared to the prior art, in particular reduced losses due to the skin effect, and contribute to achieving high fill factors.
[0013] The problem of the invention is solved in particular by the combination of features according to claim 1, wherein the dependent claims represent at least expedient embodiments and further developments.
[0014] It is therefore assumed in particular that a tape conductor device is designed to be used in alternating current supplied electrical machines, in particular electric motors.
[0015] The tape conductor device has at least two elongated, rigid tape conductor elements with contact devices for coupling in and out of electric current, wherein the tape conductor elements provide a current path.
[0016] The ribbon conductor elements form a layered arrangement with existing or added electrical insulation in between.
[0017] In particular, separately manufactured ribbon conductor elements can be provided with a completely enclosing insulation and are subsequently stacked on top of each other.
[0018] In principle, at least two strip ladder elements are stacked on top of each other. Along their length, particularly during a full transposition section, the strip ladder elements exchange their positions within the stack, i.e., top or bottom, at least once.
[0019] This position exchange is achieved without twisting or rotation through complementary step changes of the belt ladder elements, carried out by means of material forming.
[0020] Preferably, especially to achieve a compact structure, the cross-sectional shapes of the belt ladder elements vary in the area of the step changes.
[0021] In the area of step transitions, the cross-sectional area remains largely constant despite varying cross-sectional shape. By maintaining a constant cross-sectional area, hotspots in the ribbon conductor assembly are avoided or minimized.
[0022] Furthermore, the geometric shape of the surface allows for frequency adjustment with regard to the aforementioned use in alternating current powered electrical machines, especially motors.
[0023] According to the invention, the step transitions are thus achieved by means of material forming, wherein the area of the step transitions is free of discontinuities. This means that all transitions are realized smoothly without edges, so that all areas of the respective conductor cross-sections contribute to current conduction. This avoids losses, particularly in the form of resistance heat. The step transitions each have mutually complementary, tape-conductor-width-side stepbacks, which interlock as a result of the stack assembly, whereby the assembly is achieved without twisting by one-dimensional movement of the layers relative to each other.
[0024] The respective ends of the tape conductor elements can already have an electrically insulated section during manufacturing and are electrically connected there.
[0025] The stack arrangement is adapted in terms of its dimensions, length, and cross-section to the dimensions of slots in the stator or core of an electric machine, and completely and uniformly fills these slots. The cross-section of the strip conductor elements outside the step-change area has the shape of an ideal rectangle or square without a radius or radii at at least one of the corners. In this respect, the strip conductor elements can be made of copper, a copper alloy, or aluminum, which undergoes a straightening process before the step-change formation.
[0026] The stator of an electrical machine according to the invention, comprising stator slots, at least one coil with at least one conductor assembly, receives the respective conductor assembly in the slots. After the conductor assembly is inserted, at least one of the step changes is located essentially in the axial center position with respect to the axial extent of the respective stator slot of the stator.
[0027] The step increments have a stair-like contour. Each step of the respective step increment can run essentially at right angles or at oblique angles to the longitudinal dimension of the belt ladder element.
[0028] It is therefore possible to implement each step of the respective step change diagonally to the longitudinal extent of the belt ladder element.
[0029] According to the invention, a solid forming tool for manufacturing a strip ladder device as described further comprises a one- or multi-part forming punch which acts on the strip ladder element in such a locally limited manner that the respective step is formed in a continuous step and subsequently, while maintaining a holding force, the respective joining step can be carried out in the area of the step.
[0030] In a further development of the invention, the cross-sectional area (at least one cross-section, optionally all cross-sections) in the region of the step changes or in the region of at least one step change (and / or in the region of at least one setback, in particular a setback on the broad side of a strip ladder element) is adapted to the cross-sectional area of the other sections of the strip ladder elements (in particular, at least at one cross-section of the step change, at least substantially equal to the cross-sectional area of at least one other, optionally all other, sections of the strip ladder elements not located within a step change). Preferably, a high degree of uniformity and consistency of the cross-sectional areas is desired.
[0031] The step jumps preferably each have complementary, tape-conductor-element-side step-backs, which further preferably interlock as a result of joining the stack (and in particular thus create the desired compact arrangement).
[0032] The stacking arrangement of the tape ladder device preferably comprises at least two tape ladder elements, each with at least one or at least two step jumps, wherein the respective ends of the tape ladder elements are electrically connected.
[0033] The stack arrangement is preferably adapted in terms of its dimensions in length and cross-section to the dimensions of slots in the stator or core of an electric machine.
[0034] In a preferred embodiment, the tape conductor device is part of a rectangular coil or forms so-called hair pins of electrical machines.
[0035] The ribbon conductor device can, in various embodiments, be provided in only a subset of a number of individual pins (hair pins) of a coil and / or electrical machine (or in all pins). For example, the ribbon conductor device can be provided in at least 1%, preferably at least 8%, more preferably at least 25%, and / or at most 90%, preferably at most 70%, and more preferably at most 50% of the pins. This allows the advantages of the ribbon conductor device to be used in a targeted and measured way.
[0036] Preferably, pins located further inwards within a given stator are equipped with the tape conductor device, and pins located further outwards are not.
[0037] The ribbon conductor elements are preferably stacked closely together over a flat area and / or at least almost gap-free and / or tightly packed, with an intermediate layer of very thin insulation.
[0038] The insulating layer can be introduced in a continuous process between opposing surface sides of the tape conductor elements during the joining of the tape conductor elements to form the tape conductor device.
[0039] This represents an alternative or supplement to the also possible full-surface (forming an insulating layer) encasing of the individual tape conductor elements before joining them to form the tape conductor device.
[0040] The thickness (d1) or layer thickness of the insulating layer is many times smaller than the thickness (d2) of the strip conductor elements (e.g., d1 ≤ 0.5*d2 or d1 ≤ 0.1*d2 or d1 ≤ 0.05*d2 and / or d1 ≥ 0.001*d2 or d1 ≥ 0.005*d2). Due to the small potential differences between the strip conductor elements, the thickness of the insulating layer can be extremely thin, resulting in the desired compact design of the strip conductor device with a correspondingly high fill factor for the intended application. For example, the thickness is in the range of ≤ 40 µm.
[0041] The ribbon conductor elements are, for example, made of solid copper or copper alloy material and / or solid aluminum or aluminum alloy material and / or manufactured using additive manufacturing technology.
[0042] The strip ladder elements are produced by material forming. For example, solid strip materials, preferably with a rectangular cross-section, can be deformed, preferably in such a way that one or more step changes are formed. The joining of the strip ladder elements to obtain the strip ladder device can be automated.
[0043] The manufacture of the strip conductor device, particularly if it forms or incorporates a hairpin geometry, can be carried out conventionally, specifically involving bending and / or welding. Generally, it can involve (simple) replacement of hairpins with the present strip conductor device.
[0044] The ladder elements of the ladder device are preferably arranged (in cross-section, particularly perpendicular to the longitudinal extent) (at least outside the respective step increment(s) and / or outside at least one setback, particularly the ladder element's broad-sided setback) and / or over at least 50% or at least 90% of their length) in (only) one row above the other. In contrast to, for example, a Röbel rod, where at least two rows are arranged side by side, this saves space.
[0045] The ladder elements of the ladder device are preferably arranged (in cross-section, particularly perpendicular to the longitudinal extent) (at least outside the respective step step(s) and / or outside at least one setback, in particular a setback on the side of the ladder element, and / or over at least 50% or at least 90% of their length) such that they are not adjacent to each other. In contrast to, for example, a Röbel rod, where (in cross-section) at least two rows are always arranged next to each other, this saves space.
[0046] The belt ladder elements of the belt ladder device can run in the same direction (at least outside the respective step step or steps and / or outside of at least one return step, in particular belt ladder element wide-sided return step, and / or over at least 50% or at least 90% or at least 95% of their length).
[0047] The respective center lines of the tape ladder elements of the tape ladder device can be identical (at least outside the respective step step or steps and / or outside of at least one step back, in particular tape ladder element broad-sided step back, and / or over at least 50% or at least 90% or at least 95% of their length) in a perpendicular projection onto a bottom side of a lowest and / or a top side of an uppermost layer (generally: outside of an outermost layer).
[0048] The tape ladder device and / or the respective tape ladder can have at least or exactly two layers, or at least or exactly three layers, or at least or exactly four layers.
[0049] The tape ladder device and / or the respective tape ladder can have at least one or exactly one, or at least two or exactly two, or at least four or exactly four, or more position jumps (step jumps). At least two or exactly two position jumps (step jumps) can collectively represent a transposition to one position two steps ahead (or, with a corresponding number of position jumps, to the third position ahead or even further away).
[0050] A (single) step change or step change can lead (directly) from one position to the next one, or even further.
[0051] The tape ladder device can have at least two or exactly two, or at least three or exactly three, or more tape ladders.
[0052] The (respective) step change (or position change) is preferably provided in a respective active area of the tape conductor or tape conductor device. Generally, at least one or exactly one, or at least two or exactly two, or at least three or exactly three, or more transpositions (position changes) can be present in the (respective) active area of a stator slot (per tape conductor device).
[0053] The (respective) step step or step steps are preferably arranged in such a way that a (maximum) suppression or reduction of eddy current and / or circulating current losses within an entire winding (total copper winding) takes place.
[0054] Preferably, several step changes within the active area of the stator or motor are arranged at constant intervals.
[0055] The tape conductor device can be configured as a haripin or as a replacement for (conventional) hairpins and / or within a profile wire winding, especially to minimize eddy current losses within the winding.
[0056] The ribbon conductor device can be configured or used as an alternative or in addition to stranded wire.
[0057] The invention will be explained in more detail below with reference to an exemplary embodiment and with the aid of figures.
[0058] This shows: Fig. 1 a perspective view of a tape conductor device, joined by joining two tape conductor elements according to the invention, which are already provided with an enveloping insulating layer; Fig. 2 a side view similar to the one after Fig. 1, however, with embedding an insulating layer in the joining process of two tape conductor elements with step jumps to manufacture the tape conductor device; Fig. 3 a schematic side view of an alternative embodiment of a tape ladder device; Fig. 4 a tape conductor device designed in a U-shape (to form a hairpin) in an oblique view; Fig. 5 a schematic sectional view of a stator with strip conductor devices according to one embodiment; Fig. 6 a representation analogous Fig. 5 according to a further embodiment; Fig. 7 a representation analogous Fig. 5 according to a further embodiment; Fig. 8 an embodiment of a tape ladder device consisting of two mutually complementary tape ladder elements with corresponding width-side recesses, designed in such a way that the joining of the two elements without twisting is possible by moving the layers one-dimensionally relative to each other in accordance with the arrow representation and Fig. 9 a schematic representation in the form of cross-sections of belt conductor elements in the area outside the step changes, wherein Fig. 9 a) a reduction of the outer radii symbolizes the optimization of the fill factor with respect to the respective stator slot and the avoidance of air gaps, 9 b) an additional exemplary elimination of inner radii resulting in a further increase in the fill factor, and 9 c) a reduction of the spacing of the strip conductor elements by minimizing the insulation layer thickness, resulting in a further improvement of the fill factor and thus of the efficiency of strip conductor devices implemented according to the invention.
[0059] The belt ladder device according to the figures consists of two belt ladder elements 1; 2, which are stacked on top of each other.
[0060] The ladder elements 1; 2 exchange their positions along their ladder length during a full transposition section VS with respect to their position in the stack (cf. Fig. 2, where VS is shown schematically here and ends at the beginning of the position jump, which then completes the full transposition).
[0061] In the example shown, the belt conductor element 1 is located in the left-hand section after Fig. 1 is at the top and changes its position downwards via a step jump SP.
[0062] Conversely, the situation is different with the belt ladder element (belt ladder section) 2, which changes its position from below via the step step SP upwards according to the figurative representation. Fig. 1 changes.
[0063] The figurative representation shows that the exchange of position of the belt ladder elements is achieved without twisting or rotation by complementary step jumps SP of the belt ladder elements, for example by means of material forming.
[0064] In the area of the step transitions SP, the cross-sectional shape of the belt ladder elements 1; 2 varies.
[0065] By shaping the area of the step transitions SP, it is possible to keep the cross-sectional area largely constant despite varying cross-sectional shape, thus avoiding current-induced hotspots.
[0066] Preferably, the cross-sectional area of at least one cross-section (possibly all cross-sections) in the area of a (respective) step step corresponds at least 0.6 times, preferably at least 0.9 times and / or at most 1.5 times, preferably at most 1.1 times, to the cross-sectional area of at least one cross-section (possibly all cross-sections) of the respective tape conductor outside the step step.
[0067] Preferably, the (minimal) width of a respective belt conductor in the area of a (respective) step step is smaller than the width of the corresponding belt conductor outside the step step, preferably by at least 10% or at least 30% smaller and / or by at most 80% smaller.
[0068] Preferably, the (maximum) thickness (height) of a respective tape conductor in the area of a (respective) step step is greater than the thickness of the corresponding tape conductor outside the step step, preferably by at least 10% or at least 50% greater and / or by a maximum of 200% greater.
[0069] It is in line with the invention that the cross-sectional area in the area of the step changes SP is at least substantially adapted to the cross-sectional area of the other sections of the belt ladder elements 1; 2 and is designed to be identical if possible.
[0070] The step jumps SP each have complementary, band-ladder-element-side return jumps 3, which result from joining the gap (see Fig. 1) interlock.
[0071] As a result of joining the tape conductor elements 1; 2, preferably with a mechanical device, a consideration of the Fig. 1 from right to left a belt ladder device with two belt ladder elements 1; 2, which are stacked closely together, without gaps and tightly, so that a compact arrangement is created.
[0072] In particular, when uninsulated ribbon conductor elements 1; 2 are used, a thin insulating layer 4 is introduced between the ribbon conductor elements 1; 2 during the process of stacking them on top of each other (see Fig. 2).
[0073] This insulating layer 4 can already be pre-shaped with regard to the contour in the area of the step changes SP or can consist of a material that, when the tape conductor elements 1; 2 are brought together and joined, takes on their shape in the area of the step changes.
[0074] The strip conductor elements 1; 2 can consist of solid copper or copper alloy material, which is advantageous for more efficient and cost-effective manufacturing. Using known, preferably applied material forming methods, solid strip materials with a preferably rectangular cross-section can be deformed such that the relevant step transitions SP are formed, and the joining of the strip conductor elements 1; 2 to obtain the strip conductor device can be carried out easily and automatically.
[0075] A key advantage of the presented strip conductor device, due to its non-linear conductor structure with step increments, is the reduction of the area exposed to a slot transverse magnetic field when used in electrical machines. Furthermore, current displacement is minimized. By simply adjusting the conductor geometry, the device can accommodate different frequency spectra during the operation of electrical machines. Any potentially increased current density in the step increment region can be reduced through geometric adjustment and optimization.
[0076] Comparing the copper losses as a function of the conductor geometry, starting from known twisted conductor structures, with the copper losses of the ribbon conductor device according to the invention, the frequency-dependent increase in losses when using a ribbon conductor device with a stacked arrangement of ribbon conductor elements and step step, especially at higher frequencies between 500 and 1500, possibly between 600 and 1000 Hertz, is significantly reduced.
[0077] In Fig. Figure 3 shows a schematic side view of an alternative embodiment of a tape ladder device. The tape ladder device comprises tape ladder elements 11; 12; 13, which form three layers and can have several step changes (for example, from a lowest or first layer shown in the figure to a middle or second layer and from there to a highest or third layer).
[0078] Fig. Figure 4 shows a U-shaped (hairpin) tape conductor assembly. It can be seen that only one transposition (position jump) is provided in the respective active area A of the tape conductor. Generally, at least one, or exactly one, or at least two, or exactly two, or at least three, or exactly three, or more transpositions (position jumps) can be present in the (respective) active area of a stator slot (per tape conductor assembly). Preferably, the position jump SP divides the active area A into sections of equal length. This also applies to multiple transpositions. From a manufacturing perspective, this offers the advantage of being able to produce a tape conductor with fixed, predetermined spacing, regardless of its width. This ensures that the symmetry conditions for suppressing stray fields are met under all circumstances.
[0079] In Fig. Figure 5 is a schematic sectional view of a stator 14 with a plurality of strip conductor devices 21, 22, 23, 24, 25, and 26 (within the stator slot). The exact number of strip conductor devices is not essential here. It is evident that all strip conductor devices are designed according to the basic principle of the present disclosure (according to claim 1). In the alternative embodiment according to Fig. 6. Several inner tape conductor devices are designed according to the basic principle of the present disclosure (specifically four, which is not intended to be limiting), and further tape conductor devices (here specifically two) are located further outwards, without corresponding step increments according to the present disclosure. In the present case, specifically two-thirds of the tape conductor devices (which is not intended to be limiting) are designed with step increments according to the present disclosure.
[0080] In a further different embodiment according to Fig. 7. Only the innermost two tape conductor devices are designed with at least one corresponding step step according to the present disclosure, and the outer ones (here: four) are not. Only one third (which should not be understood as restrictive) of the tape conductor devices are thus designed with at least one step step according to the present disclosure.
[0081] The embodiment according to Fig. Figure 8 shows another variant of the formation of the step jumps (as a schematic representation), where it is possible to carry out the joining of the elements 1; 2 by moving them towards each other in a one-dimensional, in the example shown horizontal direction (see arrow representation).
[0082] Fig.Figure 9 ac shows additional possibilities for the pretreatment of strip conductor materials with the aim of obtaining the most optimal cross-sectional area possible outside the step transitions, thus avoiding air gaps caused by outer and / or inner radii. Air gaps within the stator slots not filled by the strip conductor material lead to electrical losses. A further increase in the so-called copper fill factor is achieved by minimizing the insulation between the strip conductor layers.
[0083] It has been shown that, given the voltage differences between the respective layers present here, ranging from a few volts to 10 volts, insulation in the range of ≤ 40 µm is sufficient.
[0084] It should be noted here that all parts described above, considered individually and in any combination, especially the details shown in the drawings, are claimed as essential to the invention. Modifications to this are familiar to those skilled in the art.
[0085] Furthermore, it is noted that the broadest possible scope of protection is sought. Therefore, the disclosure contained in the claims can also be specified by features that are described by further features (even if these further features are not necessarily included). It is explicitly noted that parentheses and the term "in particular" are intended to emphasize the optionality of features in the respective context (which does not imply that a feature is mandatory in the corresponding context without such indication). The term "element" is preferably intended to denote a coherent structure that may, in turn, be connected to at least one other structure (to form a potentially monolithic and / or internally immovable overall structure) or may be distinct from all other structures. Reference symbol list 1, 2 Bandleiter elements 11; 12; 13 Bandleiter elements 14 Stator 21; 22; 23; 24; 25; 26 Belt ladder device A active area of the band conductor SP step jump or layer jump VS Full transposition line QUOTES INCLUDED IN THE DESCRIPTION
[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature
[0000] DE 10 2012 218 986 A1
[0003] DE 39 23 310 C1
[0005] DE 197 54943 A1
[0007] CH 15177 A
[0008] WO 2022 / 029008 A1
[0009] WO 2024 / 121095 A1
[0012]
Claims
A ribbon conductor device designed for use in alternating current supplied electrical machines, in particular motors, comprising at least two elongated, rigid ribbon conductor elements with contact devices for coupling in and out of electric current, wherein the ribbon conductor elements (1; 2) provide a current path and the ribbon conductor elements (1; 2) form a layered arrangement with electrical insulation (4), wherein the ribbon conductor elements (1; 2) are stacked on top of each other in the installed state and exchange their positions with respect to their position in the stack at least once along their conductor length in the course of a full transposition section (VS), furthermore the position exchange is realized without twisting or rotation by complementary step changes (SP) of the ribbon conductor elements (1; 2), furthermore the step changes (SP) are carried out by means of material forming, in the area of the step changes (SP) the cross-sectional area shape of the ribbon conductor elements (1;2) varies, but in the area of the step transitions (SP) the cross-sectional area remains constant despite varying cross-sectional shape, characterized in that the area of the step transitions (SP) is free of discontinuities.; Belt ladder device according to claim 1, characterized in that the cross-sectional area in the area of the step jumps (SP) is adapted to the cross-sectional area of the other sections of the belt ladder elements (1; 2) and the transitions within the step jumps (SP) are smooth and edgeless. Belt ladder device according to one of the preceding claims, characterized in that the step jumps (SP) each have mutually complementary, belt ladder element-width-side return steps (3) which interlock as a result of joining the stack, wherein the joining is carried out without twisting by one-dimensional movement of the layers relative to each other. Tape conductor device according to one of the preceding claims, characterized in that it comprises a stacking arrangement of at least two tape conductor elements (1; 2) each with at least one or at least two step jumps (SP), wherein the respective ends of the tape conductor elements (1, 2) have an insulation-free section and are electrically connected there. Tape ladder device according to claim 4, characterized in that the stacking arrangement is adapted with respect to its dimensions in length and cross-section to the dimensions of slots in the stator or core of an electrical machine and completely fills these slots in terms of area. Tape conductor device according to one of the preceding claims, characterized in that the tape conductor elements (1; 2) are stacked in a compact arrangement with a thin insulating layer (4) having a thickness ≤ 40 µm and are tightly packed over a flat area, without gaps, and tightly packed. Belt ladder device according to claim 6, characterized in that the cross-section of the belt ladder elements outside the area of the step jumps (SP) corresponds to an ideal rectangle or square without radius at at least one of the corners. Tape conductor device according to claim 6 or 7, characterized in that the tape conductor elements (1; 2) consist of a solid copper or copper alloy material which is subjected to a straightening process before the formation of the step jumps (SP). Belt ladder device according to one of the preceding claims, characterized in that the step jumps (SP) have a stair-like contour. Belt ladder device according to claim 9, characterized in that the respective step of the respective step jump runs essentially perpendicular to the longitudinal extent of the belt ladder element. Belt ladder device according to claim 9, characterized in that the respective step of the respective step jump has an inclined profile to the longitudinal extension of the respective belt ladder element. Tape conductor device according to one of claims 1 to 11, characterized in that it is a component of a rectangular coil or a hairpin. Belt ladder device according to claim 12, characterized in that the active area (A) is divided into sections of equal length by the respective step step or steps (SP). Stator of an electrical machine comprising stator slots with at least one coil, with at least one tape conductor device according to one of the preceding claims, wherein the at least one step step (SP) is located after the insertion of the tape conductor device essentially in an axial central position with respect to the axial extent of the respective stator slot. Solid forming tool for the production of a strip ladder device according to one of claims 1 to 13, consisting of a one- or multi-part forming punch which acts on the strip ladder element in such a locally limited manner that in a continuous step the respective step is formed and subsequently, while maintaining a holding force, the respective joining step can be carried out in the area of the step.