WO2022029006A1

WO2022029006A1 - Method for additively manufacturing a three-dimensional component having at least one winding

Info

Publication number: WO2022029006A1
Application number: PCT/EP2021/071291
Authority: WO
Inventors: Axel Helm
Original assignee: Technische Universität Bergakademie Freiberg
Priority date: 2020-08-06
Filing date: 2021-07-29
Publication date: 2022-02-10
Also published as: EP4193454A1; DE102020120802A1

Abstract

The invention relates to a method for additively manufacturing a three-dimensional component having at least one winding, in particular a coil (17) for an electric motor, by layer-by-layer application of a construction material and locally selective solidification of the construction material by irradiation with at least one beam impinging on the construction material, wherein the irradiation is configured in such a manner that a thickness of the winding at least in sections is less than or equal to 1.0 mm, preferably is less than or equal to 0.5 mm, and/or wherein at most ten, preferably at most five, furthermore preferably at most two irradiation paths lie next to one another, or there is precisely one irradiation path, at least in sections in a thickness direction.

Description

Process for the additive manufacturing of a three-dimensional component with at least one winding

description

The invention relates to a method for the additive manufacturing of a three-dimensional component with at least one winding, in particular with at least one coil for an electrical machine, in particular an electric motor or generator, and a corresponding component with at least one winding, in particular with at least one coil for an electrical machine , In particular an electric motor or generator.

Methods and corresponding devices for the additive manufacturing of three-dimensional components by layer-by-layer application and locally selective solidification of a construction material are known in principle from the prior art. At least one appropriate coating unit is usually provided for layer-by-layer application. At least one corresponding irradiation unit (e.g. comprising at least one laser and/or an electron beam device, in particular an electron beam gun and/or arc device) is usually provided for the locally selective solidification.

Furthermore, it is known from the prior art, namely DE 10 2014 20 305 A1 and US 2019/0260252 A1, manufacturing methods and corresponding devices for additive manufacturing also for the production of coils for to use electric motors. US 2019/0260252 A1 deals in particular with the attachment of insulation. DE 10 2014 201 305 A1 describes the production of a coil with cooling channels.

The known from the prior art production of such coils or components in general with at least one winding is considered to be in need of improvement.

It is the object of the invention to propose a method for the additive manufacturing of at least one component with at least one winding (or with at least one coil) and a corresponding manufacturing device, whereby the manufacturing effort should be reduced as much as possible, in particular with the simultaneous realization of a space-saving construction.

This object is achieved in particular by the subject matter of claim 1.

In particular, the object is achieved by a method for the additive manufacturing of a three-dimensional component with at least one winding, in particular with at least one coil for an electrical machine, in particular an electric motor or generator, by applying a construction material in layers and locally selective hardening of the construction material by irradiation with at least one jet impinging on the construction material.

A general idea of the invention is therefore characterized by a method for additive manufacturing by applying a construction material in layers and locally selective solidification of the construction material by irradiation with at least one beam impinging on the construction material, for the production of a three-dimensional component with at least one winding, in particular with at least to use a coil for an electrical machine, in particular an electric motor or generator.

According to a first particularly preferred aspect of the invention, an axial length of the winding, in particular the coil (17), is stretched by at least 30%, preferably at least 100%, from a relaxed initial state (or the winding/coil is at least designed in such a way that this is possible), in particular without plastic deformation (at 20°C) and/or compressed by at least 30%, in particular without plastic deformation (at 20°C) (or the winding/coil is at least designed in such a way that this is possible).

According to the first (particularly preferred) aspect of the invention (which can be provided as an alternative or in addition to the second aspect below), the at least one winding (in particular coil) can be expanded from a relaxed initial state (at 20 °C) by at least 30%, preferably at least 100% %, even more preferably at least 300%, possibly at least 500%, are stretched, in particular without undergoing plastic deformation, and/or are compressed by at least 30%, possibly at least 50% (in particular without undergoing plastic deformation).

According to a further particularly preferred aspect of the invention, the irradiation is configured in such a way that a thickness of the winding, at least in sections, is less than or equal to 5.0 mm, preferably less than or equal to 1.0 mm, more preferably less than or equal to 0.5 mm and/or or wherein in one thickness direction (possibly a respective coating plane) at least in sections at most 50, preferably at most 10, more preferably at most 5, more preferably at most 2 or exactly one, irradiation path(s) are (directly) next to each other.

A central idea of the second (particularly preferred) aspect is to use the additive manufacturing process to achieve a comparatively small thickness (conductor thickness or material thickness) of the winding, preferably <1.0 mm and/or at most 20, possibly at most 15 or at most 10 radiation paths next to each other.

According to the second aspect, it is particularly important to make the material thickness (thickness) of the winding or coil as small as possible, which is achieved in a synergistic manner using the additive manufacturing method proposed here. As a result, a corresponding winding can be produced in a simple manner. In particular, it is possible to provide a comparatively elastic winding (coil) in a simple manner, which can be correspondingly stretched and/or compressed, for example to apply insulation and/or to polish a surface of the winding (coil).

A component with at least one winding can be understood to mean a (possibly one-piece, in particular monolithic) component which comprises a winding or is formed by such a winding (thus possibly having no further structures apart from the winding). The winding can in particular be a coil for an electrical machine, in particular an electric motor or generator.

A winding is to be understood in particular as a winding up of a material in the solid state of aggregation around an (actual or physical or geometrical) axis. The winding can be single or multi-layer. Preferably, the winding (or coil) is configured (or arranged) for application to a stator of an electric motor. The winding (or the coil) should preferably have at least one 360° rotation (=individual winding), preferably at least 2 or at least 5 or at least 10 such 360° rotations (or individual windings arranged in a row).

An extension of the winding in the axial direction should also be understood in particular as the length of the winding. The axial direction is preferably defined here by the (geometric) winding axis (or coil axis) around which the winding is wound (or attached). This axis is preferably straight, but can also be curved if necessary. In the case of a curved axis, the length should be understood as a distance (along the winding axis) between two end points of the winding that lie on the axis (whereby in this perspective the points of the winding should also include those points that are inside the winding, considering these in particular as an envelope).

The (respective) extent of the winding (coil) in mutually perpendicular directions, both of which are perpendicular to the (respective) longitudinal direction, is also referred to below as width and height.

A thickness of the winding is to be understood in particular as its material thickness in the longitudinal direction. This can be constant (e.g. with a plate-like configuration of the winding or coil) or vary. If the thickness varies, it should preferably apply that the above condition (thickness < 5.0 mm, preferably < 1.0 mm, more preferably < 0.5 mm, optionally < 0.2 mm) for at least 20%, preferably at least 50%, even more preferably at least 90%, possibly for the entire material length of the winding (or coil).

A material length is to be understood in particular as a length of the material of the winding (or coil), ie a length of the winding in an (imaginary) state in which it is aligned (or stretched).

In particular, the winding (coil) can vary in a cross-section perpendicular to the (local) extension of the winding material (for example with a circular geometry of the material). Then the above condition should preferably apply for the entire cross-section (ie especially at the point where the thickness is at its maximum).

A thickness direction is to be understood as meaning the direction in which the thickness extends. In this direction, alternatively or additionally, at most 50, preferably at most 10, more preferably at most 5, more preferably at most 2 or exactly one irradiation path should lie directly next to one another.

The thickness or direction of thickness preferably extends (during additive manufacturing) in a (respective) coating plane (at least in sections), or perpendicularly thereto or in yet another direction.

According to the embodiment, the winding axis extends parallel to a construction plane (surface of a construction platform) (at least in sections), or perpendicularly thereto or in yet another direction.

A stretching or compression of the coil is to be understood in particular as meaning a corresponding increase (stretching) and shortening (compression) of its length. It should preferably be possible for the winding (in particular the coil) to be stretched (and/or compressed) considerably and to return (elastic) to its initial state after this stretching (or compression).

With such a configuration, the winding (coil) can be further processed or equipped in a simple manner (in particular by polishing and/or cleaning and/or introducing electrical insulation). For example, the coil can first be stretched, then insulation can be introduced (particularly as explained in detail below) and then (using an elastic restoring force) returned to its original state (or to an intermediate state, for example if the insulation prevents the coil or winding retracts completely).

As a result, the production and post-processing of such windings or coils is simplified.

In general (regardless of the question of whether plastic deformation takes place), in a preferred embodiment of the method according to the second aspect, the winding (coil) is stretched by preferably at least 30%, more preferably at least 100%, even more preferably at least 500% and /or compressed by at least 30%, possibly at least 50%.

This is generally advantageous in order to be able to process or adapt the coil further (and/or to be able to equip it with other materials, such as an insulating material).

The preferred flexibility of the winding (coil) offers advantages in particular for post-processing, such as cleaning (e.g. with compressed air and/or ultrasound), by polishing (e.g. by means of sandblasting) and/or insulation (e.g. by casting compounds, insulating resins and/or solid insulators) .

In particular, insulation can be introduced comparatively easily, since accessibility is ensured by the (elastic) deformability. For example, so-called prepregs (pre-insulated foils) can be easily inserted. Also a complete wetting with potting compounds or Insulating resins can be guaranteed more easily if the winding (coil) is impregnated or varnished in an initial state (especially stretched state) and brought (pressed) to the (final) length after the insulating process.

During production, a gap (distance) between adjacent winding sections (individual windings) (at least in sections) is preferably less than or equal to 1 mm, preferably less than or equal to 0.2 mm, possibly less than or equal to 0.1 mm. The gap can (at least in sections) be larger than 0.05 mm, possibly larger than 0.08 mm. The gap (distance) between adjacent winding sections (individual windings) can alternatively or additionally be at most equal to the thickness of at least one of the two adjacent winding sections, preferably at most 0.5 times the thickness of at least one of the two adjacent winding sections.

By means of such measures, a construction space of a system for the additive production of the winding (coil), in particular a SLM system (DMLS), can be used comparatively efficiently. In particular, individual lines (that is to say preferably singular irradiation paths which preferably do not directly adjoin another irradiation path, with no spacing in between) can be produced lying comparatively close to one another. Particularly in the case of a line exposure (cf. FIG. 5), comparatively small gaps (of, for example, less than or equal to 0.1 mm) can be achieved here (due to good surface properties).

In general, a wall thickness of a (respective) winding or coil can be adjusted by a targeted parameterization of the irradiation device. For example, a reduced thickness (wall thickness or material thickness) can be achieved by increasing the speed (with the same power and layer thickness), since the energy input per area decreases with increasing speed. This can result in a narrower weld pool, which results in a thinner component.

In embodiments, a (respective) irradiation path can run (at least in sections) perpendicular to the direction of thickness (and/or parallel to a (particularly local) extension of the material of the winding or coil). Alternatively or additionally, a (respective) irradiation path can run from one end of the component in the area of a (the) respective irradiation path to the other end of the component in the area of the respective irradiation path (at least essentially) without interruptions. Programming such individual vectors (or such continuous irradiation paths) has the particular advantage that the process is comparatively less error-prone and as a result there are fewer defects in the material, which in turn can impair conductivity, for example. In conventional irradiation methods, triangulation, which can arise after a (virtual) construction of the surface geometries by creating a corresponding file, can lead to an interruption of the irradiation path or the vectors during the transfer to the actual irradiation. When the additive manufacturing process is actually carried out, these interruptions lead to holding times of the irradiation device (delays), which in turn can lead to pores in the material. This problem can be solved by setting or programming continuous vectors and thus each conductor (per layer) can only be produced by a single vector, for example. A significant reduction in production time can also be achieved as a result.

In further embodiments, several (e.g. at least 2 or at least 4 and/or at most 100 or at most 20) irradiation paths can lie (directly) next to one another (next to one another) in the thickness direction, which are preferably traversed in opposite directions (antiparallel) to a respective adjacent irradiation path. In particular, individual vectors can be placed next to one another along the component geometry in order, for example, to be able to realize greater wall thicknesses (thicknesses) than can be produced by a single irradiation line (single vector). From this, a surface quality can be improved (in particular a surface roughness can be reduced) and/or a construction time can be shortened. "Along the geometry" is to be understood in particular that the individual vectors are aligned parallel to the (local) extension of the winding material or coil material (i.e. preferably not at an angle to it). Such an alignment can reduce jump points, which reduces the production time can be significantly reduced, for example by 2/3 (if the jump points are reduced from 12 to 4, for example). The wall thickness (thickness) can be adjusted as follows: As already explained above, a wall thickness can be adjusted by an irradiation parameter when manufacturing windings or (individual) coils by (multiple) irradiation. The sum of the wall thickness can then result in the total wall thickness. Alternatively, a certain wall thickness can be achieved in a targeted manner by choosing a hatch distance (distance between the irradiation lines) such that a total sum of the irradiations results in the necessary (desired) wall thickness. It is also possible to keep the sum of irradiation sections constant and only change a distance between the irradiation vectors in order to achieve the desired level. Advantageously, the hatch distance is reduced, since increases tend to lead to (more) porosity.

It can be difficult to build windings or coils, at least in the case of certain aspect ratios (from, for example, thickness to height=1:8). For example, in certain coils there can be a ratio of 1:166 (a thickness or material thickness is, for example, 0.3 mm; a height is, for example, 50 mm). With such thin cross-sections, the tension created by the melting process during additive manufacturing can have a negative effect on the component and warpage can occur. These distortions can go so far that the components become unusable. This should preferably be counteracted.

The individual windings of the (overall) winding or coil are preferably moved as close together as possible, for example to within 0.1 mm or less (for example only 0.05 mm). It is particularly important to ensure that individual winding sections do not fuse together (unless this is desired). Furthermore, walls (supporting walls) can be integrated between individual winding sections (or two adjacent individual windings), which can be positioned at a similar distance (e.g. one wall per at least 3 and/or at most 20 individual windings). Preferably, the walls are removed after fabrication.

Such measures can lead to a minimization of delays. The following mechanisms play a role here: Due to the fact that components are comparatively close together, one can be damaged by the manufacturing process generated heat can be dissipated evenly. Cooling times can be influenced by a comparatively high (maximum) packing on a construction platform and thus a delay in recurring melting on a component. A support function can be implemented, both between the components and between support walls and components. In general, it is proposed to build the individual windings of the (total winding or coil) in such a way that they are positioned perpendicular to the construction platform (or construction level).

The thickness direction preferably runs parallel to the (respective) coating plane and/or construction platform surface. Alternatively, the direction of thickness can run perpendicularly to the respective coating plane and/or construction platform surface.

In embodiments, the winding has an at least substantially constant thickness. Alternatively or additionally, the winding (coil) can be configured in a plate-like manner. A plate-like configuration means in particular that a respective winding section has the shape of a plate.

In embodiments, a cross section of the winding (coil) may vary. Alternatively or additionally, at least one end winding can have a surface-enlarging structure for cooling. Alternatively or additionally, at least one end winding can be shortened in the radial direction compared to the other areas of the winding.

For example, within an electric motor, heat can be generated due to a resistance of the conductor (which is formed by the winding or coil). The conductivity of conventional (metallic) conductors, such as in particular copper or a copper alloy, decreases with increasing heat. As a result, efficient cooling for electric motors is comparatively important. Since the (respective) end winding is more accessible when used in an electric motor, for example compared to a material (e.g. copper) that is located in the stator slot (active part), cooling is comparatively efficient there. A comparatively simple possibility is now, according to the embodiment, to enlarge an area of the end windings in order to to achieve a more efficient cooling effect of a fluid (gas, preferably air, or liquid, preferably water). An increase in surface area (in the area of the end winding) can preferably be achieved by a large number of (e.g. radially aligned) projections (e.g. in the form of webs and/or nubs and/or pins and/or (outward) fibers). Other geometric forms are also possible. In combination with a possible fluid cooling, fixations for the mechanical fastening of at least one line of the fluid cooling can preferably already be provided during manufacture. At the same time, a large cooling surface can be achieved particularly advantageously with a comparatively short end winding geometry. The (necessary) installation space also plays a role here.

Furthermore, according to the embodiment, a shortening of the end winding is proposed. A radial extent of the coil material in the region of the end winding can be less than 0.9 times, preferably less than 0.7 times, possibly less than 0.5 times (on average) the radial extent of the coil material outside the area of the winding head. For example, a cross section through the respective winding (or coil) in the region of the end winding can have a different (e.g. more compact) shape or (in a side view) be bent or angled. In embodiments, a cross-sectional area through the winding (coil) in the area of the end winding can be at least 0.5 times, preferably at least 0.8 times and/or at most 1.5 times, preferably 1.2 times as large as one Cross-sectional area in the remaining areas. Alternatively or additionally, a radial extension in the area of the end winding can be a maximum of 0.8 times, preferably a maximum of 0.5 times as large as a radial extension in the other areas of the winding (coil).

In embodiments, a cross section of the winding (coil) in the region of the end winding can be rectangular or triangular, for example. In the case of a triangular configuration, it is particularly preferred if adjacent winding sections (coil sections) form respective triangles in cross section, which are aligned alternately (so that a point of one triangle points in exactly the other direction than the point of the respective adjacent triangles). Sections of the winding (coil) can have at least one indentation (possibly exactly one indentation on one side, particularly in the case of a rectangular configuration) and/or run in waves or zigzags at least in sections (particularly in the region of a winding overhang).

A segmentation of stators is common in order to simplify the assembly of windings (or coils, in particular made of copper). A corresponding tooth base can make it difficult to attach such coils.

In order to nevertheless be able to implement a comparatively simple assembly, a corresponding geometrical characteristic (in particular in combination with a process-related flexibility) is proposed according to the embodiment. An indentation (provided, for example, on one or both sides) (which preferably forms corresponding deformation ears) can simplify assembly of a (closed) coil on a segmented stator with a tooth base. Preferably, no mechanical deformation by a winding machine is necessary, which allows an increase in installation space, since in particular no plastic elements are required on the stator tooth. For example, the respective winding (with a bulge or deformation ears) can be plugged on one side of a stator segment. In order to now also move a second side over the tooth root, the bulge (or the deformation ears limiting the bulge) can be used for elastic deformation over the tooth root.

Other geometries can also have such an effect, for example a waveform or a zigzag shape that can be used to spread the entire coil geometry.

The winding can have a polygonal, in particular quadrangular, configuration. This means in particular that a plurality of individual windings or each individual winding has a polygonal, in particular quadrangular, configuration (i.e. forms a polygon or in particular a quadrangle in a plan view along the longitudinal direction of the overall winding). More preferably, such a square configuration is combined with a square cross-section (as discussed above). The winding (coil) can have no pitch, at least in sections. Preferably, the winding (coil) has at least one 360° revolution (in particular based on at least one individual winding) only over an angular range of less than or equal to 180°, preferably less than or equal to 120°, possibly less than or equal to 90° slope up. As an alternative or in addition, in the case of a square configuration of the winding, there can be a slope on only two sides or only on one side of the square. A pitch of the winding (coil) means that it advances in the longitudinal direction. If there is no gradient, it is therefore preferably the case that the winding (with respect to the longitudinal direction) does not progress any further. In a view perpendicular to the longitudinal direction, an incline can be seen in that the angle relative to the longitudinal direction is less than 90°, for example less than 88° or less than 85° or less than 80° and/or greater than 45°. A comparatively space-saving design can be achieved by means of such measures (or jump points in the course).

Optionally, the winding (coil) has non-melted areas, at least in sections, which are preferably held together by sintering processes and/or adjacent melted areas in the composite material. In this way, in particular, a reduction in eddy currents (preferably through an effect similar to that in the case of laminated cores of the stator) can be achieved. A laminar structure is conceivable (i.e. in particular such that layers of melted material alternate with layers of non-melted material, particularly in the case of a rectangular cross section or a plate-like configuration of the winding or coil). For example, a line spacing can be selected comparatively large enough that a non-merged area is created between the exposure lines. This can be mechanically strengthened due to sintering processes.

In the case of a triangular cross-section through the winding material (or coil material), there can also be a laminar structure or a structure with non-fused regions arranged at an angle (possibly at random to one another).

In general, the winding (coil) can be produced using different irradiation modes. For example, a winding (comparatively thin in relation to the material thickness, in particular in the longitudinal direction of the coil) can be produced by irradiation with (only) one irradiation path width. A distance between an individual winding of the (overall) winding and a respective adjacent individual winding can be set in such a way that unsolidified build-up material (after the irradiation) remains between them. After solidification by irradiation, unsolidified powder can be removed so that individual windings with the thickness (material thickness) of an irradiation track remain.

In an alternative irradiation mode, a (porous) winding can be produced by irradiation with an irradiation track width. A distance to the respective next irradiation path can be selected in such a way that the two (adjacent) solidified irradiation paths are connected by a porous layer (sintered layer or layer with sintered areas). In this case, the build-up material between the two (adjacent) irradiation paths may not be completely melted, but only partially melted (or partially melted). A single winding then comprises two (parallel) irradiation paths and an intermediate space porously connecting these irradiation paths (and optionally further parallel irradiation paths with corresponding intermediate spaces). The porous part can be used to reduce eddy currents.

In a further irradiation mode, a comparatively wide winding can be produced by irradiation with several irradiation path widths (in particular without a gap, as explained in the previous paragraph).

In modifications, comparatively thick individual windings can also contain porous winding areas. For example, a single winding of two or more, z. B. four (parallel) irradiation paths that are directly adjacent to each other, a porous intermediate layer and two or more, z. B. four, further (parallel) irradiation paths can be constructed.

In general, a winding (as a series of individual windings) can comprise a number of parallel conductors or conductor tracks (formed by irradiation tracks during manufacture). If a distance between the parallel conductor tracks (made by corresponding irradiation tracks) set comparatively large, when manufacturing the winding, an area can arise between the conductor tracks in which the construction material is not (completely) melted in a materially bonded manner, so that free spaces arise between the parallel conductor tracks, which can lead to a reduction in eddy currents.

The winding, in particular the coil (for an electrical machine, in particular an electric motor or generator), is preferably polished and/or cleaned. This is preferably done by means of sandblasting.

According to a third (particularly preferred, fundamentally independent) aspect of the invention, a method for producing a three-dimensional component with at least one winding, in particular a coil for an electrical machine, in particular an electric motor or generator, is proposed, comprising a method step of additive manufacturing, in particular According to one of the preceding aspects, a three-dimensional component with at least one winding, in particular a coil for an electrical machine, in particular an electric motor or generator, by applying a construction material in layers and locally selective solidification of the construction material by irradiation with at least one beam impinging on the construction material , and at least one process step of surface treatment and/or covering (of a winding or coil surface), wherein an axial length of the winding, in particular coil, is stretched by h is carried out and a surface treatment and/or covering of the winding, in particular the coil, is carried out in the stretched state, and/or a compression of an axial length of the winding of the coil takes place, with a surface treatment and/or covering of the winding being carried out before the compression, in particular coil, is carried out in the stretched state.

In embodiments, the surface treatment step includes polishing, preferably including sandblasting.

Alternatively or additionally, the surface treatment step can include cleaning, preferably with a liquid and/or gaseous cleaning agent. The surface covering preferably includes the arrangement of (electrical) insulation at least partially on the surface of the coil material, in particular between adjacent individual windings.

Stretching the winding (coil) is particularly advantageous in order to ensure accessibility for surface treatment processes. This means that polishing can be carried out at any point on the component using comparatively coarse media (e.g. when sandblasting). Shading can advantageously be avoided in this case. The winding (coil) may be expanded before polishing (and/or compressed after polishing and/or contract by itself due to an elastic restoring force).

As an alternative or in addition to polishing, a cleaning step (for example using a fluid, in particular gas or liquid) can be carried out. For this purpose, too, the coil is preferably stretched and/or compressed (or compressed) after cleaning or can contract independently after stretching due to an elastic restoring force.

More preferably, the winding (coil) is stretched (or spread) prior to placement of insulation or a (e.g., liquid) source material for insulation. Alternatively or additionally, after the insulation or a (possibly liquid) starting material for the insulation has been arranged, the coil can be compressed and/or contract independently due to an (elastic) restoring force.

The arrangement of insulation can include:

- a provision of a solid starting material that is at least partially melted or dissolved or dissolved (and solidifies again and thereby enters into a connection with the winding and possibly holds adjacent winding sections together) and/or - Provision of a liquid or pasty starting material (which forms a connection with the winding when it solidifies and possibly holds adjacent winding sections together) and/or

- a provision of a solid insulating material to be laid between adjacent winding sections (preferably without prior melting and/or prior dissolving) and/or

- a provision of insulation produced by an additive manufacturing process (in particular designed as an insulating winding that is preferably hollow on the inside) and/or

- A provision of a preferably internally hollow insulating winding (which is preferably connected to the winding, for example by being screwed in like a screw).

In particular with a thin material thickness (or thin wall thickness) according to the second aspect and/or a comparatively high flexibility (according to the first aspect), there can be a significant improvement in the accessibility of individual windings and thus in the insulating capability. An elongation (spreading) is possible with little effort (expenditure on tools).

Different insulation systems in both the liquid and the solid phase can be used. This enables the use of known and already used insulation (for example wire enamel, epoxy resin and/or polyamide), but also other insulation.

In order to be able to achieve complete wetting in comparatively small gaps, in particular of less than 0.1 mm, it is possible to stretch the winding (coil) into a bath and then, after (complete) wetting, to open it with the help of a tool, for example final dimension to compress.

Another possibility is solid insulation. An insulating layer (insulating film), e.g. B. Mylar®, be arranged, which can provide (full-surface) insulation. This type of insulation is only possible due to a special (wall-like, see above) geometry. So-called prepregs represent another (similar) possibility. These are pre-impregnated layers (foils) which comprise a plastic (e.g. resin, in particular epoxy resin) and are coated on both sides with a Nomex® foil, for example. Such a pre-impregnation can, for example, fuse with the winding geometry (conductor geometry) by pressing, in particular in combination with a heat treatment (in an oven) and thereby ensure an adhesive bond. This can also be referred to as primary insulation, since the resin is then (directly) on the winding material (conductor) and also (particularly) clings to surface roughness (over the entire surface). On the other hand, inserted solids, such as a Mylar® foil, can be referred to as secondary insulation.

Additively manufactured solids are a further possibility for solid-state insulation. These can consist of wound (coil-like) geometries. An assembly can thus be made possible, for example, by screwing it in like a screw. Stereolithography, for example, can be considered as a production process, in which thermally stable materials in particular can also be processed.

In order to create a distance between the (individual) windings and the insulation, spacers (e.g. spacer plates) can be arranged between the individual windings in order to specify an insulation thickness (in the case of casting). The stretched (spread) coil can then be soaked and pressed to size, with spacers providing the minimum spacing.

A distance (when arranging the insulating material or a preliminary stage of the insulating material) can also be provided by granules in the insulating material. A stretched (spread) coil can then be soaked and pressed to size, with the granulate dictating the minimum spacing.

According to a fourth (independent) aspect of the invention (which is preferably combined with a first and/or second and/or third aspect of the invention) there is proposed a method for arranging a coil on a stator segment of an electric motor, comprising a method for additively manufacturing a three-dimensional component with at least one winding, in particular a coil for an electric motor, by applying it in layers of a construction material and locally selective hardening of the construction material by irradiation with at least one beam impinging on the construction material, with at least one elastic section of the coil being displaced outwards in the radial direction, the coil then (or at least in sections at the same time as the outward displacement process ) is brought over a projection of the stator, in particular a tooth base, with the outwardly displaced section then being displaced inward again in the radial direction due to its elasticity.

According to the invention, a three-dimensional component with at least one winding, in particular a coil for an electrical machine, in particular an electric motor or generator, is proposed which, according to the first and/or second and/or third and/or fourth aspect of the invention (and possibly continuing education features) is produced.

According to the invention, a coil on a stator segment is also proposed, in particular, which is produced using the above method.

According to the invention, an electrical machine, in particular an electric motor or generator, comprising a three-dimensional component and/or at least one coil on a stator segment, produced using the above method, is also proposed.

According to the invention, the use of a method for the additive manufacturing of a three-dimensional component with at least one winding, in particular a coil for an electrical machine, in particular an electric motor or generator, by applying a construction material in layers and locally selective solidification of the construction material by irradiation with at least one the beam impinging on the construction material, is proposed (the method preferably having further features according to the first and/or second and/or third and/or fourth aspect of the invention and optionally corresponding further developing features).

The invention preferably includes the additive production of coils (tooth coils) for electric motors, and in particular their (series) production, assembly and compaction on the end winding. Conventionally manufactured coils are subject to different restrictions due to the use of wires or wire-like cross-sections. Losses due to (poorly) filled stator slots, skin effect and eddy currents are current problems that can be reduced or eliminated by manufacturing using an additive process.

Various advantages can be achieved through the additive manufacturing of (tooth) coils compared to conventional winding technology. Conventional winding machines for conventional windings are comparatively expensive and in principle have to be redesigned for each new motor type. Additive manufacturing systems, on the other hand, can produce any winding without additional tooling costs. For the production of conventional windings, forming processes (bending, drawing, upsetting) are necessary, which have different effects on the final result (winding on a laminated core). Forming zones can have poorer conductivity due to partial material changes. During the actual winding process, large mechanical forces can occur because springback requires overcoming the elastic deformation range. Such a process can often be validated and optimized over months. This extends the development time by orders of magnitude and is not necessary for additively manufactured (tooth) coils.

The production of first samples, prototypes and series can be accelerated. A necessary forming work requires stable insulating bodies or base bodies, which are installed as the basis of the winding with conventional winding technology. When manufacturing coils using additive manufacturing, these can be reduced or saved, which in turn means that more material (in particular copper or copper alloy) can be integrated in the stator slot. The processing of wires or wire-like cross-sections as conductors in electrical machines (motors, generators) does not result in optimal filling of the stator slot. Filling factors of over 70% can be made possible through additive manufacturing, since the conductor cross-section can be ideally adapted to the slot. With conventional manufacturing methods, stator windings cannot be manufactured in any geometry. For example, walls that are often less than 1 mm thick cannot be formed at a 90° angle without tearing or buckling. However, these thin sheet-like conductor cross-sections are advantageous, since power losses due to skin Effect and eddy currents can be reduced. In addition, there is a loss of installation space at the winding head due to the specified bending radii when processing conventional wires. Additive manufacturing of coils means that the shape of the end winding is not tied to the restrictions of conventional manufacturing and can therefore be designed and manufactured in a very space-saving manner. In addition, the procedure according to the invention makes it possible, in particular, for electric motors to use other insulation systems than previously. Since forming processes are no longer necessary here, much simpler potting compounds can be used for insulation, which are characterized by high dielectric strength. A (higher) mechanical strength can be achieved through the high flexibility of the insulator, which is no longer required.

One possibility of (series) production is so-called stacking, in which as many parts as possible are packed comparatively close together and/or on top of each other in order to make ideal use of the construction platform. In order to be able to (easily) separate the components from one another, it is possible to grade the individual layers of the components. This makes it possible to produce an area that does not belong to the component with a comparatively porous parameter, with the result that the individual coils can be easily broken apart.

Furthermore, it should be noted that the winding (coil) can already be printed in a spread state, in order to simplify post-processing operations (especially in terms of accessibility).

Connections can be provided in different configurations (for example, crimp and/or plug-in connections).

The structural material can preferably comprise at least 30% by weight, in particular at least 90% by weight: one metal or more metals, preferably copper or a copper alloy; and/or aluminum or an aluminum alloy; and/or iron or an iron alloy. Each of the metals mentioned can form at least 10% by weight or at least 50% by weight or at least 90% by weight of the building material. In general, various additive manufacturing methods are possible within the scope of the present invention.

In a powder bed-based manufacturing process, powder can be applied in one plane, with structures within the plane being irradiated. As a result of the irradiation, the powder can be melted and then cooled. The irradiation can take place by means of a laser, electron beam and/or electric arc.

Alternatively, powder for the required layer thickness can be applied in a powder supply system only in the area that is to be solidified and solidified by irradiation (by means of laser, electron beam and/or arc).

In a wire feed system, instead of a powdered material, a build material can be provided in wire form. The wire can be melted and cooled by means of radiation (laser, electron beam and/or arc).

A powder bed-based manufacturing process is particularly preferably used.

Further embodiments of the invention result from the dependent claims.

The invention is described below using exemplary embodiments which are explained in more detail using the figures. Here show:

1 shows a schematic oblique view of a stator of an electric motor according to the invention;

2 shows a coil according to the invention in a (schematic) side view;

FIG. 3 shows the coil according to FIG. 2 in a stretched state; FIG. 4 shows a highly schematic plan view of a coil section;

Fig. 5 shows the coil section according to FIG. 4 with different

irradiation vectors;

6 shows a schematic section of a coil according to the invention in a state in which an insulation is being arranged;

FIG. 7 shows a detail from FIG. 6 in an enlarged representation; FIG.

8 shows a schematic representation of a winding section;

FIG. 9 shows the winding section according to FIG. 8 in the stretched state;

10 shows a section of a coil according to the invention (in the region of the end winding);

11 shows an alternative embodiment of a coil according to the invention (in the area of the end winding);

12 shows an alternative embodiment of a coil according to the invention (in the area of the end winding);

13 shows a schematic representation of a coil according to the invention in the region of the end winding;

FIG. 14 shows a representation analogous to FIG. 13 in a different embodiment (in the region of the end winding);

15 is a plan view of a spool according to the invention;

16 shows a segmented stator in an oblique representation (with tooth base);

17 shows a schematic view of a winding head end in plan view; FIG. 18 shows the winding head end according to FIG. 17 in the stretched state;

FIG. 19 shows the winding head end according to FIG. 17 in an even further stretched position

Status;

20 shows a schematic side view of a winding of a coil on a stator;

FIG. 21 shows a schematic illustration analogous to FIG. 20 in a different embodiment of the coil;

FIG. 22 shows the coil according to FIG. 21 in a different view;

Figure 23 is a side cross-sectional view through a spool;

FIG. 24 shows a cross-sectional view through the coil analogous to FIG. 23 in a different embodiment;

FIG. 25 shows an illustration analogous to FIG. 23 according to a different embodiment of the coil;

26 is a schematic representation of a coil with spacers; and

Fig. 27 is a schematic representation of a coil with granulate between

single windings.

In the following description, the same reference numerals are used for the same parts and parts with the same effect.

1 shows a schematic representation of an electric motor produced using the method according to the invention or a corresponding stator (with a partially exposed view of the interior).

The electric motor preferably has a stator 10 with stator teeth 11 and stator slots 14 . Furthermore, coils 17 with respective end windings 18 and connections 16 can be seen. 2 shows a coil 17 according to the invention in an initial state. FIG. 3 shows the coil 17 according to FIG. 2 in a stretched state (in a schematic side view).

Insulation is particularly preferably introduced after the coil 17 has been stretched (according to FIG. 3). The coil can then be compressed or contract again.

4 shows a highly schematic plan view (in the direction of thickness) of a coil 17. In the present rectangular shape, the longer side defines the direction in which the coil material extends (in this section). 4 also shows irradiation vectors which are arranged antiparallel according to a conventional hatching method. As can be seen, there is a large number of jump points.

FIG. 5 shows an analog section (to FIG. 4). Here, however, the irradiation vectors are co-directional with the extension of the material of the coil. As a result, jump points can be reduced, which can shorten the construction time. In addition, the surface is improved, in particular smoother.

Figure 6 illustrates an advantageous method of placing insulation. Here, spacers 24 can be provided on individual windings, which in turn are spaced apart from one another by means of a fixation 19 . After the arrangement of an insulating material (e.g. by casting), these spacers 24 can be removed.

8 schematically shows a winding section.

FIG. 9 shows the winding section according to FIG. 8 in the stretched state.

A gripper 20 is shown in FIGS. 8 and 9 (see FIG. 8) by means of which the coil can be stretched, preferably over one or more tension straps 12 . After the insulating material has been arranged, the (active) stretching can be stopped and/or (active) compression can be carried out. The clamping strap(s) 12 can (can) be produced during the additive manufacturing process and, if necessary, removed after the operation. 10 to 12 show various possibilities for enlarging the surface area in the area of the end winding 18. In the cross-sectional representation according to FIG. 10, projections 21 can be seen (here, for example, which is not mandatory, three in a row in the longitudinal direction of the coil). The projections 21 according to FIG. 10 run straight (radially) and can be designed, for example, as webs or pins. FIG. 11 shows an embodiment basically like FIG. 10, but in this case the projections 21 (to further increase the surface area) are curved (multiple bends). Another solution is shown in FIG. Here, the protrusions 21 are simply curved (and bend towards each other, but this is not mandatory).

Fig. 13 shows a section of a coil 17 according to the invention with a structure for (radial) shortening of the coil in the area of the end winding 18.

The coil sections in the region of the end winding 18 are bent here (in a side view) (partly in one direction, partly in the other direction, it would also be conceivable for all sections to be bent in the same direction). As a result, the coil can be shortened in the radial extent (in the region of the end winding) (from a radial extent h2 without a kink to a radial extent h1 without necessarily reducing a conductor cross-sectional area).

Fig. 14 shows a solution with a triangular cross-section of the coil 17 in the area of the end winding 18. This also allows the coil to be shortened in the radial extent (in the area of the end winding) (from a radial extent h2 without changing the geometry to a radial extent hl without mandatory to reduce a conductor cross-sectional area). In concrete terms (which is not mandatory, however), the triangles are arranged alternately in such a way that the tip of one triangle points in the opposite direction to the tip of the respective neighboring triangle.

FIG. 15 shows a (schematic) plan view of a coil 17 according to the invention with a bulge 22 which is delimited by deformation ears 23. FIG.

16 shows a segmented stator with a tooth base. The coil 17 according to FIG. 15 is now preferably placed on one side of the stator segment according to FIG. 16 (ie moved over the tooth base on one side). In order to now also move the second (opposite) side over the tooth root, the deformation ears are used for elastic deformation over the tooth root.

FIG. 17 shows an alternative geometry for such a method, which here has a wavy end winding. The waveform can be stretched as shown in Figure 18 (by an appropriate force F) and further stretched (as shown in Figure 19).

Fig. 20 shows a conventional coil winding in the form of a helix.

21 shows an alternative embodiment for a coil winding. Here (in the view according to FIG. 21) the individual windings of the coil 17 are oriented perpendicular to the axial extent of the coil. This is achieved (see FIG. 22) by appropriate compensation (in the form of jump points) on one of four sides of the winding.

When looking at the course of an individual winding, there are different ways of constructing the winding (coil). The simplest is a continuous helix. However, it is advantageous for the coil to have a course with corresponding sections, referred to below as "jump points", at which the increase (or the gradient required to form the coil) takes place, i.e. where the transition to the next winding or the next revolution takes place this now, for example, on only one (or two) of four sides of a winding, it can be seen that it is possible to integrate a further winding, since the skew of a continuously and circumferentially increasing helix takes place at the beginning and end of the coil and space is lost as a result .

23 shows a laminar structure of the coil material. The coil material here has a rectangular cross section. The laminar structure consists of (completely) fused sections and interruptions outlined by dashes or, in particular, porous sections 13 between the fully melted sections where the coil material is only partially (or not at all) melted.

24 shows an analogous structure, but with a triangular cross-section of the conductor material. Here, too, however, the individual fused and non-fused regions are arranged in a laminar manner.

Figure 25 shows a chaotic arrangement of merged and unmerged areas.

Such measures reduce eddy current losses.

26 shows a coil with (here schematically: three) individual windings which are separated from one another by spacers 26, preferably in the form of spacer plates. The spacers 26 (spacer plates) specify an insulating thickness when casting.

27 shows (here in the schematic representation: two) individual windings with granules 25 in between. The coil spread by the granules can be soaked and pressed to size, with the granules being able to specify the minimum spacing.

At this point it should be pointed out that all the parts described above, viewed individually and in any combination, in particular the details shown in the drawings, are claimed to be essential to the invention. Modifications of this are familiar to those skilled in the art.

Reference List

F force hl,h2 extension

10 stator

11 stator tooth

12 turnbuckle clamp porous section

14 stator slot

16 connection coil winding head fixation gripper protrusion bulge deformation ear spacer granule spacer

Claims

Claims Method for the additive manufacturing of a three-dimensional component with at least one winding, in particular a coil (17) for an electrical machine, in particular an electric motor or generator, by applying a construction material in layers and locally selective solidification of the construction material by irradiating the construction material with at least one impinging jet, wherein an axial length of the winding, in particular the coil (17), is or at least can be stretched from a relaxed initial state by at least 30%, preferably at least 100%, in particular without plastic deformation, and/or by at least 30 % is compressed or at least can be compressed, in particular without plastic deformation. Method, in particular according to claim 1, for the additive manufacturing of a three-dimensional component with at least one winding, in particular a coil (17) for an electrical machine, in particular an electric motor or generator, by applying a construction material in layers and locally selective solidification of the construction material by irradiation with at least one beam impinging on the build material, the irradiation being configured such that a thickness of the winding at least in sections is less than or equal to 1.0 mm, preferably less than or equal to 0.5 mm and/or wherein in a thickness direction at least in sections at most ten, preferably at most five, more preferably at most two or exactly one, irradiation path(s) is/are next to each other/ -en. Method according to one of the preceding claims, wherein a gap between adjacent winding sections is less than or equal to 1 mm, preferably less than or equal to 0.2 mm and/or at most equal to a thickness of at least one of the two adjacent winding sections, preferably at most 0.5 times the thickness of at least one of the two adjacent winding sections. Method according to one of the preceding claims, wherein a respective irradiation path runs perpendicular to the thickness direction and/or runs at least essentially without interruptions from one end of the component in the region of a/the respective irradiation path to the other end of the component in the region of the respective irradiation path. Method according to one of the preceding claims, in which several irradiation paths lie next to one another in the direction of thickness and are preferably traversed in opposite directions. Method according to one of the preceding claims, wherein the thickness direction runs parallel to the respective coating plane and/or building platform surface or wherein the thickness direction runs perpendicular to the respective coating plane and/or building platform surface. Method according to one of the preceding claims, wherein the winding has an at least substantially constant thickness at least in sections and/or is configured like a plate. Method according to one of the preceding claims, wherein a cross section of the winding varies and/or preferably at least one end winding (18) has a surface-enlarging structure for cooling and/or at least one end winding (18) is shortened in the radial direction compared to the other areas of the winding. Method according to one of the preceding claims, in which the winding has at least one indentation and/or runs in a wavy or zigzag manner at least in sections, in particular in the region of a winding overhang (18). A method according to any one of the preceding claims, wherein the winding has a polygonal, in particular quadrangular, configuration. Method according to one of the preceding claims, wherein the winding has no gradient at least in sections, preferably in at least one 360° revolution only over an angular range of less than or equal to 180°, more preferably less than or equal to 120°, and/or at a square configuration of the winding has a pitch on only two or only on one side of the square. Method according to one of the preceding claims, wherein the winding (coil) has non-melted areas at least in sections, which are preferably held together by sintering processes and/or adjacent melted areas in the composite material. Method for producing a three-dimensional component with at least one winding, in particular a coil (17) for an electrical machine, in particular an electric motor or generator, comprising a method step of additive manufacturing, in particular according to one of the preceding claims, of a three-dimensional component with at least one winding, in particular a coil (17) for an electrical machine, in particular an electric motor or generator, by applying a construction material in layers and locally selective solidification of the construction material by irradiation with at least one beam impinging on the construction material, and at least one process step of a surface treatment and/or - covering, wherein an axial length of the winding, in particular the coil (17), is stretched and a surface treatment and/or covering of the Winding, in particular coil, is carried out in the stretched state, and/or an axial length of the winding of the coil is compressed, with a surface treatment and/or covering of the winding, in particular coil, being carried out in the stretched state before compression. The method of claim 13, wherein the surface treatment step comprises polishing, preferably comprising grit blasting. Method according to claim 13 or 14, wherein the surface treatment step comprises cleaning, preferably with a liquid and/or gaseous cleaning agent. Method for producing an insulated winding, in particular an insulated coil (17) for an electrical machine, in particular an electric motor or generator The method according to any one of the preceding claims 13 to 15, wherein the surface covering comprises the placement of insulation. A method according to claim 16, wherein the winding prior to the placement of the insulation or one, e.g. B. liquid, starting material for the insulation is stretched and / or is compressed after the arrangement of the insulation or a, possibly liquid, starting material for the insulation and / or contracts independently due to an elastic restoring force. A method according to any one of claims 15 or 16, wherein the placement of the insulation comprises:

- Provision of a solid starting material which is at least partially melted or dissolved and/or

- Provision of a liquid or pasty starting material and/or

- a provision of a solid insulating material, which is placed between adjacent winding sections and / or

- a provision of insulation produced by an additive manufacturing process and/or

- A provision of a preferably internally hollow insulating winding. A method of arranging a coil (17) on a stator segment of an electric motor, comprising the method according to any one of the preceding claims, wherein at least an elastic portion of the coil (17) is displaced radially outwards, the coil (17) then over a projection of the stator, in particular a tooth base, is moved away, the outwardly displaced section then being displaced inward again in the radial direction due to its elasticity. Three-dimensional component with at least one winding, in particular coil (17) for an electrical machine, in particular an electric motor or generator, manufactured according to one of claims 1 to 18. Coil (17) on a stator segment manufactured according to claim 19. Electrical machine, in particular electric motor or generator , comprising a three-dimensional component according to claim 20 and/or at least one coil (17) on a stator segment according to claim 21.