Electromagnetic mat for a stator or rotor component of an electric machine

Abstract

A method of producing an electromagnetic mat for forming a stator or rotor component of an electric machine. The electromagnetic mat has structural fibre lengths and a plurality of winding fibre lengths for forming a winding fibre that is in a winding pattern for forming one or more windings of the electric machine. The electromagnetic mat is formed by forming a support structure with the structural fibre lengths and inserting the winding fibre lengths into the support structure so that the winding fibre lengths extend across the structural fibre lengths and the structural fibre lengths lock the winding fibre lengths in position.

Claims

1. A method of producing an electromagnetic mat for forming a stator or rotor component of a multiphase ironless or slotless electric machine, wherein the electromagnetic mat comprises: non-conductive structural fibre lengths; and a plurality of continuous winding fibre lengths for forming winding fibres that are in a winding pattern for forming multiple windings of the multiphase ironless or slotless electric machine, the method comprising: (a) forming a support structure with the non-conductive structural fibre lengths, and (b) inserting the continuous winding fibre lengths into the support structure so that the continuous winding fibre lengths extend across the structural fibre lengths and the structural fibre lengths lock the continuous winding fibre lengths in position to form the electromagnetic mat, wherein the inserting the continuous winding fibre lengths into the support structure comprises weaving the continuous winding fibre lengths back and forth across the structural fibre lengths and aligning the continuous winding fibre lengths in a winding pattern so as to create a moving electromagnetic field when induced with an alternating current or a constant electromagnetic field when induced with direct current.

2. The method according to claim 1, wherein the electromagnetic mat is formed with additional fibre lengths having predetermined electromagnetic, thermal, mechanical and/or electrical properties.

3. The method according to claim 1, comprising a step of shaping the electromagnetic mat into a shape for forming at least a part of the stator or rotor component of the electric machine.

4. The method according to claim 3, wherein the step of shaping the electromagnetic mat is performed on a base or by layering the electromagnetic mat onto itself to form the stator or rotor component.

5. The method according to claim 4, comprising shaping the electromagnetic mat by arranging or rolling the electromagnetic mat onto the base.

6. The method according to claim 5, comprising a step of connecting at least one of the structural fibre lengths to the base before the electromagnetic mat is rolled onto the base.

7. The method according to claim 4, comprising a step of forming the stator or rotor component with the base as a part of the stator or rotor component.

8. The method according to claim 1, comprising a step of incorporating an object within the rotor or stator component by providing the object between layers of the electromagnetic mat.

9. The method according to claim 1, comprising a step of impregnating the electromagnetic mat with a solidifiable material, and solidifying the solidifiable material to set the electromagnetic mat in the shape for forming the stator or rotor component.

10. The method according to claim 1, wherein the electromagnetic mat is formed as part of a continuous forming process that is for forming a plurality of electromagnetic mats, and wherein the method comprises cutting the structural fibre lengths to form the electromagnetic mat for forming the stator or rotor component of an electric machine.

11. The method according to claim 10, comprising a step of shaping the electromagnetic mat into a shape for forming at least a part of the stator or rotor component of the electric machine, wherein the step of shaping the electromagnetic mat is performed before the step of cutting the structural fibre lengths.

12. The method according to claim 1, wherein the electromagnetic mat is performed using a machine that is controllable to allow adjustment of one or more of a winding pattern and dimensions of the electromagnetic mat.

13. An electromagnetic mat for forming a stator or rotor component of a multiphase ironless or slotless electric machine, comprising: non-conductive structural fibre lengths that form a support structure; and a plurality of continuous winding fibre lengths forming winding fibres that is in a winding pattern for forming multiple windings of the multiphase ironless or slotless electric machine, wherein the continuous winding fibre lengths have been woven into the support structure so that the continuous winding fibre lengths extend back and forth across the structural fibre lengths and the structural fibre lengths lock the continuous winding fibre lengths in position, and wherein the continuous winding fibre lengths are aligned in a winding pattern configured to create a moving electromagnetic field when induced with an alternating current or a constant electromagnetic field when induced with direct current.

14. The electromagnetic mat according to claim 13, further comprising utilizing property modifying fibre lengths in the electromagnetic mat, said property modifying fibre lengths having predetermined electromagnetic, thermal, mechanical and/or electrical properties.

15. The electromagnetic mat according to claim 13, wherein the structural fibre lengths extend in a longitudinal direction of the electromagnetic mat and the winding fibre lengths extend in mainly transversal direction of the electromagnetic mat.

16. The electromagnetic mat according to claim 13, wherein the electromagnetic mat is shaped to form a stator or rotor component of an electric machine.

17. The electromagnetic mat according to claim 16, wherein the electromagnetic mat is shaped by being arranged or rolled onto a base or layered onto itself.

18. The electromagnetic mat according to claim 17, wherein the base is a part of the stator or rotor component.

19. The electromagnetic mat according to claim 13, comprising an object incorporated within the rotor or stator component, wherein the object is between layers of the electromagnetic mat.

20. The electromagnetic mat according to claim 13, comprising a solidifiable material impregnated into the electromagnetic mat, wherein the solidifiable material is solidified to set the electromagnetic mat in the shape for forming the stator or rotor component.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Certain embodiments of the present invention will below be described by way of example only with references to the attached drawings, where:

(2) FIG. 1 shows a woven mat,

(3) FIGS. 2A-2E show electromagnetic mats (i.e. mesh fibre structures) for a stator or rotor component,

(4) FIGS. 3A-3C show further embodiments of electromagnetic mats,

(5) FIGS. 4A and 4B show EM-design patterns,

(6) FIG. 5 shows a rolled-up electromagnetic mat,

(7) FIGS. 6A-6C show stages of a production method,

(8) FIGS. 7A-7D show electromagnetic mats and connection of cut electrical conductor fibre wefts,

(9) FIG. 8 shows windings formed by continuous winding fibers,

(10) FIG. 9 shows a rolled up mat with additional property modifying fibres,

(11) FIGS. 10 and 11 show an electromagnetic mat with multiple layers,

(12) FIG. 12 shows further electromagnetic mats,

(13) FIGS. 13, 14A and 14B illustrate weaving of shaped electromagnetic mats,

(14) FIG. 15 shows the production of electromagnetic mats for four machines at the same time, and

(15) FIGS. 16A-16C show the production of an electromagnetic mat by means of twining.

DETAILED DESCRIPTION

(16) Reference is now made to FIG. 1 which shows a woven mat according to prior art. A woven mat is formed by fibres extending in longitudinal direction (i.e. a first direction) of the mat (X-fibres) called warps, and fibres extending in transversal direction (i.e. a second direction) of the mat (Y-fibres) called wefts. There exists different types of weaving which can be utilized to form such a woven mat, these include percale, twill, satin, sateen, LENO, Dutch, etc.

(17) The disclosed embodiments may be based on using weaving for the production of stator or rotor components of rotary or linear electric machines. This may be achieved by production of a woven electromagnetic mat 10.

(18) As shown in FIGS. 2A-2E for example there is provided a 2D electromagnetic mat 10 with structural fibres 20 extending in a first direction (e.g. fibre warps with non-conductive surface extending in longitudinal direction) of the electromagnetic mat and at least one winding formed by at least one winding fibre that comprises a plurality of winding fibre lengths 30, wherein each winding fibre length extends in a second direction of the electromagnetic mat. The winding fibre may be a fibre weft. For example, the winding fibre may be at least one continuous electrical conductor fibre weft extending mainly in transversal direction of the electromagnetic mat (as shown for example in FIGS. 6B, 8 and 12) or discrete (e.g. cut) electrical conductor fibre wefts extending in mainly transversal direction of the electromagnetic mat and connected (e.g. at end windings) to create at least one continuous conductor fibre weft (as shown in FIG. 3A for example). The at least one continuous electric conductor fibre weft or cut electrical conductor fibre weft is formed by electrical conductors.

(19) The winding fibre, e.g. the at least one continuous electrical conductor fibre weft, is aligned in a winding pattern that creates a moving electromagnetic field when induced with an alternating current or a constant electromagnetic field when induced with direct current from a power supply source.

(20) The winding pattern formed by the winding fibre (e.g. electrical conductor fibre weft pattern) can be adapted/modified/tailored according to different applications requiring different motor designs.

(21) For rotary machines, e.g. rotating motors, the electromagnetic mat 10 can according to one embodiment be rolled up on an object 50 (e.g. a base) (as shown for example in FIG. 6B), that may for example be a cylindrical shape. The electromagnetic mat is formed into the shape for the rotor or stator component. The electromagnetic mat 10 is cast/molded/impregnated with a solidifiable material (e.g. curable liquid potting material, such as resin or epoxy, thermosetting plastic, thermoplastic and/or a ceramic slurry etc.). The stator or rotor component may be removed from the object 50 (e.g. base) (as shown in FIG. 6C for example) or the object may form part of the stator or rotor component (as shown in FIG. 6B for example). The stator or rotor component may be assembled with the other electric machine, e.g. electric motor, components.

(22) As will be described in further detail below the electromagnetic mat may comprise property modifying fibres, i.e. fibre warps, with particular mechanical, electromagnetic and/or thermal properties.

(23) The structural fibres and/or property modifying fibres (e.g. the fibre warps with non-conductive surface and/or fibre warps with particular mechanical, electromagnetic and/or thermal properties) are fibres (i.e. threads) with particular mechanical, electromagnetic and/or thermal properties, e.g. fiberglass, Kevlar, carbon fiber, or similar, and can be in any form (such as flat, circular etc.) and any size (e.g. various diameters, length and/or width) depending on the application. Accordingly, the structural fibres and property modifying fibres may be formed from materials suitable for forming a support structure such as a grid (e.g. a single- or multi-dimensional grid/mesh). The electromagnetic mat may comprise a single type of structural fibre, or a mix of different types of fibres. The number of structural fibre lengths (i.e. warps) with non-conductive surface in the electromagnetic mat may be at least two.

(24) The structural fibres (i.e. fibre warps with non-conductive surface (and possibly fibre warps with other mechanical, electromagnetic and/or thermal properties)) will keep the winding fibre lengths (e.g. electrical conductor fibre wefts) in place in the electromagnetic mat by acting as a supporting grid. The electromagnetic mat may also comprise property modifying fibres (i.e. fibre wefts with mechanical, electromagnetic and/or thermal properties) which will be supported in the same manner as the winding fibre lengths. The property modifying fibres may also be referred to as non-winding fibres because they are not used to form windings of the electrical machine.

(25) One or more or all fibres (e.g. warps and wefts) in the electromagnetic mat may contribute to mechanical support, as well as thermal and/or electromagnetic properties of the electromagnetic mat and/or rotor or stator component.

(26) The winding fibres (e.g. electrical conductor fibre wefts) may be conductive fibres, e.g. made of copper, aluminum, or other conductive materials, as threads or fibres.

(27) In the case that discrete (e.g. cut) winding fibre lengths (e.g. electrical conductor fibre wefts) are used to form the at least one winding, the discrete winding fibre lengths arranged in the electromagnetic mat may have ends outside of the electromagnetic mat's width, i.e. outside the grid formed by the structural fibres (e.g. warps with non-conductive surface and possibly warps with mechanical, electromagnetic and/or thermal properties). The ends may be connected by desired connectors to form one or more winding fibres, e.g. continuous electrical conductor fibre warps, as described above.

(28) The winding fibres (e.g. electrical conductor fibre wefts) may have any geometrical form (e.g. flat/circular/other) and any size (i.e. any diameter, length and/or width). The particular geometry and size of the fibres may be based on the desired design of the stator or rotor component, and/or general requirements of the windings of the electric machine.

(29) Reference is now made to FIGS. 2A-2E which show electromagnetic mat 10 for a stator or rotor component the electromagnetic mat 10 is formed by structural fibre lengths 20 (i.e. fibre warps 20 with non-conductive surface) and winding fibre lengths 30 (i.e. electrical conductor fibre wefts 30) that may be used to form windings. FIG. 2A) shows eight un-connected discrete (e.g. cut) winding fibre lengths 30 (e.g. electrical conductor fibre wefts 30) inserted into the grid (i.e. support structure) formed by the structural fibres 20 (e.g. fibre warps 20 with non-conductive surface). The support structure (i.e. grid) is provided by having a plurality (in this illustration, three) parallel structural fibres. FIGS. 2B-2E show different ways/combinations of connecting the discrete winding fibre lengths 30 so to create different winding patterns (i.e. different EM-fields). In particular 2b) shows a 2-phase, concentrated winding, 2c) shows a 3-phase, wave winding, 2d) shows 2-phase, distributed winding, and 2e) shows 2-phase, wave winding, with two winding fibres 30 per phase.

(30) The EM-design is e.g. given by the inner and outer diameter of the stator or rotor component for rotary machines, and length and thickness for linear machines. This information can be used for calculating the total length of the electromagnetic mat 10, and the number of layers in total.

(31) In the case of a cylindrical rotor or stator component which is formed by rolling the electromagnetic mat 10 into a cylinder with one or multiple layers, each layer will have a larger circumference than the previous layer. It is desirable for the windings of each layer to align so as to form the slots of the rotor or stator component. As the circumference increases, each new layer will be slightly longer than the layer within. For each new “layer length” of the electromagnetic mat 10 the winding fibre lengths 30 (i.e. electrical conductor fibre wefts 30) may thus be separated more so that they fall onto their correct position. Thus the winding pattern may be arranged so that independent of diameter, the angle of slots may be constant.

(32) FIGS. 3A-3C illustrate parts of forming of a stator or rotor component. The disclosed electromagnetic mat 10 may be pulled linearly and cut, or rolled up on an object (e.g. base), typically mainly cylindrical, for rotary electrical machines. For linear electrical machines the electromagnetic mat 10 may be folded.

(33) FIG. 3A shows a grid of structural fibre lengths 20 (i.e. fibre warps 20 with non-conductive surface) and winding fibre lengths 30 (e.g. electrical conductor fibre wefts 30). In between the winding fibre lengths 30, seen in longitudinal direction of the electromagnetic mat 10, are arranged property modifying fibres 40. These property modifying fibres may for example be non-conductive fibre wefts 40. The property modifying fibres 40 can be arranged to provide insulation or other mechanical or thermal properties. As will be described below there can also be arranged property modifying fibres with electromagnetic properties in the first direction of the electromagnetic mat, e.g. in the form of fibre wefts with electromagnetic properties. In the shown embodiment the windings are formed by discrete (e.g. cut) electrical conductor fibre wefts 30 that may be connected (as illustrated by the arrows) outside of the grid formed by the structural fibres 20, e.g. with non-conductive surface, property modifying fibres 40 and winding fibre lengths 30. Underneath the illustration of the electromagnetic mat 10 is shown the resulting EM-field—alternating north and south poles—when current is applied in the direction of the arrows.

(34) FIG. 3B shows a first a 2D-pattern of winding fibre lengths, i.e. conductors 30. Initially, all winding fibre lengths 30 are the same. Letters A, B, C indicates which cut electrical conductor fibre wefts 30 that are to be connected together to form Phase A, Phase B and Phase C. Underneath the 2D-pattern of winding fibre lengths is shown how the electromagnetic mat 10 can be rolled up on a cylindrical object (e.g. base) 50.

(35) FIG. 3C illustrates folding of the electromagnetic mat 10, which may be the basis of linear electric machine components, e.g. linear motor components.

(36) FIGS. 4A and 4B illustrate exemplary winding patterns (i.e. EM-designs) for 1-phase motor and 2-phase motor, respectively, in the form of a 2D-representation. By applying a current, EM-fields will be induced.

(37) In the production method the winding pattern may be tailored according to the desired rotor or stator component design. For example the winding pattern is in the form of a barcode pattern that can be changed easily. This may be achieved for example by using discrete, e.g. cut, winding fibre lengths 30 (e.g. electrical conductor fibre wefts 30), the desired winding pattern (number of wires per slots, number of phases, etc.) can be arranged by connecting (e.g. selecting how to connect) the ending windings of the discrete winding fibre lengths 30 after they are arranged in the electromagnetic mat 10. Accordingly, this may allow for the production of a similar electromagnetic mat 10 for different electrical machines as the winding can be arranged at the end.

(38) In the case of an electromagnetic mat 10 with winding fibre lengths 30 formed from continuous winding fibres (e.g. continuous electrical conductor wefts 30) the winding pattern (electromagnetic design (number of wires per slots, number of phases, etc.)) may have to be decided during the interweaving of the fibres to form the mat, i.e. during the winding process. The winding pattern (electromagnetic design) can be modified by modifying how the continuous winding fibres 30 are inserted, i.e. inserted into a supporting grid formed by the structural fibre lengths.

(39) Thus, regardless if continuous winding fibres 30 or discrete (e.g. cut) winding lengths 30 are used to provide the winding lengths, all designs, i.e. winding patterns and/or EM designs, can be created.

(40) As it can be seen in FIGS. 3A and 3B and FIGS. 2A-2E, all discrete (e.g. cut) winding fibre lengths 30 may extend mainly in a transversal direction in the active area, and makes up a winding pattern. This pattern may be different for different types of electric machines, but as regards the production process all the discrete fibre winding lengths 30 (e.g. cut electrical conductor fibre wefts 30) may be the same until connected to other discrete fibre winding lengths 30 (e.g. cut electrical conductor fibre wefts 30). Thus, changing the winding pattern (EM-design) (the machine specifications) may only affect how the discrete fibre winding lengths 30 are connected.

(41) The diameter of the stator or rotor component may easily be changed by changing the geometry of object 50 (e.g. mainly cylindrical base) the electromagnetic mat 10 is rolled up on.

(42) FIG. 5 shows a rolled-up electromagnetic mat 10. The thickness of a stator or rotor component may easily be changed by rolling/folding more of the electromagnetic mat 10 on top of the other layers. Accordingly, the longer the electromagnetic mat 10, the thicker the component may be.

(43) Further, by adding or removing structural fibre lengths 20 (e.g. fibre warps 20 with non-conductive surface (and/or non-conductive property modifying fibre wefts 40 and/or electrical conductor fibre wefts 30)) the mechanical strength of the stator or rotor component can be altered/tailored. The mechanical strength can also be affected/altered/tailored by the tension in the fibres, i.e. fibre warps and/or wefts, and/or impregnation/molding material chosen. Further, by adding or removing other fibres also other properties can be altered, such as thermal properties.

(44) A production method for a rotor or stator component will include a step (e.g. initial step) of forming (e.g. weaving, twining or winding) electromagnetic mat 10. The method may also comprise a step (e.g. final step) of molding. The production method may further comprise one or more steps (e.g. intermediate steps) for forming through roll-up, folding or other, and/or impregnation. In the case that the mat is formed from discrete winding fibre lengths 30 (e.g. cut electrical conductor fibre wefts 30), the method may also comprise a step (e.g. intermediate step) of connecting the ends thereof (which may be referred to as connection of end windings). The sequence of steps may be altered, such that the steps may be performed in any order, depending on the application or desires, for example the method steps may be performed in the following orders:

(45) connection of ends (only when using discrete winding fibre lengths), roll-up or folding and impregnation,

(46) connection of ends (only when using discrete winding fibre lengths), impregnation and roll-up or folding,

(47) roll-up or folding, connection of ends (only when using discrete winding fibre lengths) and impregnation,

(48) roll-up or folding, impregnation and connection of ends (only when using discrete winding fibre lengths),

(49) impregnation, roll-up or folding and connection of ends (only when using discrete winding fibre lengths),

(50) impregnation, connection of ends (only when using discrete winding fibre lengths) and roll-up or folding.

(51) Reference is now made to FIGS. 6A-6C. In FIG. 6A is shown an electromagnetic mat with three phases A, B and C. It should be mentioned that even though only one winding fibre 30 (i.e. electrical conductor fibre weft 30) is shown per phase, several electrical conductor fibre wefts 30 may be used for each phase/winding.

(52) FIG. 6A illustrates a step of weaving continuous winding fibres 30 (i.e. electrical conductor fibre wefts 30) into an electromagnetic mat 10 formed by structural fibre lengths 20 (e.g. fiber warps with non-conductive surface). The pattern of fibres may be customised, based on the electric machine, e.g. motor, design.

(53) FIG. 6B illustrates a step of rolling the electromagnetic mat 10 formed by structural fibres 20 and winding fibre lengths 30 up on a cylindrical object 50 (e.g. a base 50).

(54) FIG. 6C shows a stator or rotor component, i.e. electromagnetic mat 10 after the step of molding, where the object 50, i.e. base 50, is removed, and the stator or rotor component is ready for integration in an electrical machine and connection of the windings to a power supply source and/or control system.

(55) The cylindrical object 50 (e.g. base 50) may not be removed, and may be a part of the final stator or rotor component. The properties of the object 50, e.g. base 50, may be of mechanical, electromagnetic, thermal, conductive or other nature.

(56) The step of impregnation may be performed with a solidifiable material such as a curable liquid potting material, such as epoxy, resin or similar. The solidifiable material may be applied before or after the forming, e.g. roll-up or folding, of the mat into the stator or rotor component. The fibres 20, 30, e.g. warps 20 and/or wefts 30, 40, 70, may be pre-impregnated.

(57) FIGS. 7A-7D further illustrate connection of discrete winding fibre lengths 30, e.g. electrical cut conductor fibre wefts 30, of the electromagnetic mat 10.

(58) The figures show the electromagnetic mat 10 formed with discrete winding fibre lengths 30, e.g. cut electrical conductor fibre wefts 30, through the winding process. After the electromagnetic mat 10 is created, each discrete winding fibre lengths 30 is to be connected to its respective partner(s), i.e. corresponding discrete winding fibre lengths to form the windings.

(59) FIG. 7A shows an electromagnetic mat 10 with discrete winding fibre lengths 30, e.g. cut electrical conductor fibre wefts 30. The length of the electromagnetic mat in this example corresponds to two layers. Each discrete winding fibre length 30 is to be connected to the neighboring discrete winding fibre length 30 of same phase. In the shown example the winding pattern is wave winding. FIG. 7B shows the electromagnetic mat 10 in FIG. 7A rolled up on a cylindrical object 50 seen from above. Arrows show how the cut electrical conductor fibre wefts 30 are connected, where thick arrow is used to illustrate the front side, and a dotted arrow is used to illustrate the back side.

(60) The discrete winding fibre lengths 30 may be connected before or after the rotor or stator component is formed.

(61) FIGS. 7C and 7D illustrate how discrete winding fibre lengths 30, e.g. cut electrical conductor fibre wefts 30, may be connected. Using discrete winding fibre lengths 30 may simplify the production method. In that case, connections between respective discrete winding fibre lengths 30 will have to be performed.

(62) FIG. 7C shows a connection strip 60, formed by a conductive material 61 enclosed by insulating (non-conductive) material 62 at three of the sides thereof which can be used for connection of discrete winding fibre lengths 30. Underneath this is shown how the end windings/discrete winding fibre lengths 30 of the electromagnetic mat 10 may be connected to different connection strips 60, where each phase A, B, and C, is connected to separate connection strips 60.

(63) FIG. 7D illustrates how each connection strip 60 may be inserted during the production process, where discrete winding fibre lengths 30 are inserted in the same way as in the electromagnetic mat 10.

(64) Reference is now made to FIG. 8 illustrating continuous winding fibres (e.g. electrical conductor wefts) 30. Accordingly, an alternative embodiment to the discrete winding fibre lengths is continuous electrical conductor fibre wefts 30, where instead of having separate winding fibre lengths, e.g. instead of cutting the electrical conductor wefts 30 for each time it is passed over the grid of the structural fibres 20, i.e. warps 20 with non-conductive surface, and possibly warps with other properties, in the electromagnetic mat 10, the electrical conductor fibre wefts 30 are continuous. FIG. 8 shows an example of 3-phases, with three continuous electrical conductor fibre wefts 30 per phase, where only the continuous winding fibres, e.g. electrical conductor fibre wefts, 30 are shown. The continuous winding fibres 30 can be arranged as last in—first out-principle or first in—first out-principle.

(65) Here one can for example utilise multi-shuttle weaving, where each shuttle may be in control of one or more continuous electrical conductor fibre wefts 30.

(66) Accordingly, there may be provided a multidimensional grid with multiple properties.

(67) FIG. 9 shows a further embodiment, where there are arranged property modifying fibres 70 (additional fibre wefts) with mechanical, electromagnetic and/or thermal properties, e.g. ferromagnetic, arranged between the winding fibres, e.g. electrical conductor fibre wefts 30. This may create a slotted (iron-cored) stator or rotor component. The density and variations of the fibre wefts 70 may be modified so they create unique electromechanical or mechanical (or other) properties. In the shown example the pattern alternates between electrical conductor fibre wefts 30 and fibre wefts 70 with mechanical, electromagnetic and/or thermal properties. When the electromagnetic mat 10 is rolled up, the fibre wefts 70 with mechanical, electromagnetic and/or thermal properties, e.g. formed by iron fibres, may form iron slots. This may mimic the properties of iron-cored electrical machines with iron teeth. For this setup, back-iron may not be needed. The density of fibre wefts 70 with mechanical, electromagnetic and/or thermal properties may be chosen so to create a lightweight stator or rotor component with good mechanical, electromagnetic and/or thermal properties.

(68) The electromagnetic mat 10 may also comprise, in addition to structural fibres (e.g. warps 20 with non-conductive surface), warps exhibiting mechanical, electromagnetic and/or thermal properties (i.e. property modifying fibres). These may be arranged to guide the magnetic flux, or work as a heat sink for example. For a combination of fibre warps and fibre wefts with mechanical, electromagnetic and/or thermal properties, e.g. back iron could be created by applying layers of these mechanical, electromagnetic and/or thermal properties on top of, under, or between layers.

(69) In yet a further embodiment, Z-fibres may be introduced, i.e. fibres extending in a direction that is a direction that is not in the plane formed by the first and second directions, e.g. thickness, vertical, and/or radial direction of the electromagnetic mat. By introducing Z-fibres, both electromagnetic and mechanical properties may be altered. Z-fibres may be added for support by e.g. stitching the layers of the electromagnetic mat 10 together. Z-fibres may also have e.g. flux carrying properties. In this way, iron slots may be created as described above, but with the fibre in the radial direction.

(70) In an alternative embodiment, instead of using Z-fibres directly in the production, electromagnetic mats 10 may be arranged/folded on top of each other and stitched together with fibres in the Z-direction.

(71) FIG. 10 shows an embodiment of the electromagnetic mat 10 with multiple layers. One of the major benefits of the production method may be the flexible way of adding material in the thickness direction of the formed component. This may be achieved by simply by rolling up and/or adding more layers of the electromagnetic mat 10.

(72) In the case of a rolled up mat, as the circumference increases with each new layer of the electromagnetic mat 10, the length of each layer also increases. That means that the pattern also should be more spread out, or distributed, i.e. the spacing between fibres widened. If each layer of the electromagnetic mat 10 is designed to be the same length then the slots for each new layer of the electromagnetic mat 10 will be placed slightly “off-set”. For several layers, the effect would be as shown in FIG. 11.

(73) Winding fibre lengths 30, e.g. electrical conductor fibre wefts 30 are inserted and arranged in a pattern which can be used to form a stator or rotor component, e.g. for electromagnetic purposes. The direction of the winding fibre lengths 30, e.g. electrical conductor fibre wefts 30, relative to each other, can be in several dimensions, thus providing a 2-dimensional or 3-dimensional winding for example. Reference is here made to FIGS. 12A-12D which show examples of different winding patterns which may be achieved.

(74) In FIGS. 12A-12D, the X-direction is in the direction of the structural fibres 20, e.g. fibre warps 20, while the Y-direction is the direction perpendicular to the X-direction and the direction (at least broadly) of the winding fibre lengths, e.g. fibre wefts 30, in the same plane. The Z-direction is in a direction perpendicular to both X and Y. The X direction may be parallel to the length of the electromagnetic mat, the Y direction may be parallel to the width of the electromagnetic mat and the Z direction may be parallel to the thickness direction of the electromagnetic mat.

(75) In each example shown in 12a) to d) the structural fibres 20 extend in the X-direction. In example a) the winding fibre lengths 30 extend in parallel and only in the “normal” Y-direction inside the “active area” (where the active area may be regarded as the area within the outermost structural fibres 20). In example b) the winding fibre lengths 30 extend in parallel, in the YX-direction, i.e. a direction that is non-parallel to the X or Y directions but in the plane formed by the X and Y directions. The winding fibre lengths 30 form a constant angle with the structural fibres 20 inside the “active area”. In example c) the winding fibre lengths 30 extend in parallel in both the YX and XY direction. The winding fibre lengths 30 form a constant angle with the structural fibres 20, but change direction for each “turn”. This pattern may be described as a tilted or zig-zag winding pattern. In example d) the structural fibres 20 are formed in two (or more) layers, creating a 3D-grid. The winding fibre lengths 30 extend in YX-, XY- and Z-direction, thus in all directions simultaneously. The winding fibre lengths 30 do not need to be aligned, meaning some winding fibre lengths 30 could extend in ZY-direction, some in XY-direction and some in XYZ-direction, simultaneously. Accordingly, forming a 3D winding.

(76) If the winding fibre lengths 30 are arranged in other dimensional directions than Y-direction, the forming of the stator or rotor component might have to be performed differently. For example the electromagnetic mat 10 may be plied onto something, instead of rolled up or folded. In an alternative embodiment the 3D-winding may take place on, around, or through a previously made stator or rotor component, e.g. a cube or rectangle with holes.

(77) Reference is now made to FIG. 13 which shows an electromagnetic mat 10 with bent/curved shape. An electromagnetic mat 10 may be formed (e.g. woven, twined or wound) as for the prior embodiments, but it may have a bent/curved shape. This may be achieved by having structural fibres 20 (i.e. fibre warps 20) having different lengths. This may for example be achieved by allowing different pull-up speeds for different structural fibres 20 during production of the electromagnetic mat 10. The result may be a bent/curved electromagnetic mat 10, as shown in FIG. 13. FIG. 13 shows winding fibre lengths 30, e.g. electrical conductor fibre wefts 30, inserted into a bent/curved grid formed by structural fibres 20, i.e. warps 20 with non-conductive surface. In the shown electromagnetic mat 10 the bend/curve is constant, and is a circle/arc with a constant inner and outer diameter. The winding fibre lengths 30 may be arranged in the radial direction, and the grid is formed by structural fibre lengths 20 in a tangential/circumferential direction. Also this embodiment can comprise property modifying fibres, e.g. wefts 40, 70 as well as warps with mechanical, electromagnetic and/or thermal properties as described above.

(78) By changing/altering/controlling the rate of bending (curvature) the resulting electromagnetic mat 10 may be shaped as for example a circle, an “S” or the number “8”.

(79) One application for an electromagnetic mat 10 with a bent/curved shape is electrical axial-flux machines. Electrical axial-flux machines have their magnetic flux in the axial direction. This may be achieved by providing a bent/curved electromagnetic mat 10 to create the form of a helix. By collapsing the helix a desired disc-shaped single- or multi-layered electromagnetic mat 10 may be created, as shown in FIGS. 14A and 14B, where FIG. 14A shows a helix-shaped electromagnetic mat 10, and FIG. 14B shows the collapsed helix-shaped electromagnetic mat 10 forming a disc-shaped multi-layered stator or rotor component.

(80) This embodiment may benefit from the advantages of the other described embodiments, including the design of the pattern of the winding fibre lengths 30, e.g. electrical conductor fibre wefts 30, geometry, connection of the winding fibre lengths 30, and the use of discrete or continuous winding fibre lengths, e.g. cut or continuous electrical conductor fibre wefts 30.

(81) Also this embodiment will have flexibility in that the distance between the outermost structural fibres 20, in combination with the “bending angle” (curvature), may be used to determine the inner and outer diameter of stator or rotor component. Further, the thickness of each layer, and the number of layers of the electromagnetic mat 10 may be used to decide/determine the thickness of the stator or rotor component.

(82) Also this embodiment can make use of the above described property modifying fibres, e.g. warps or wefts with other properties, i.e. the use of fibre warps or fibre wefts with mechanical, electromagnetic and/or thermal properties. For example iron fibre wefts and/or fibre warps may be used to create iron teeth or back-iron, for increased magnetic flux.

(83) Similar to the above embodiments also this embodiment can make use of the step of impregnation and molding to form the final stator or rotor component.

(84) FIG. 15 shows the production of stator or rotor components for four machines at the same time, wherein dotted lines show where the mat may be cut after the electromagnetic mat 10 is formed. For a set of equal stator or rotor components, the pattern of fibre warps and wefts will be identical. If the width of the electromagnetic mat 10 (and hence grid) formed by the structural fibres, i.e. fibre warps 20 (and possibly fibre warps with mechanical, electromagnetic and/or thermal properties) is increased (e.g. by a factor of 4 (plus optionally any necessary buffer) (e.g. by spacing the outer most structural fibres on each side further apart from each other), and the lengths of each winding fibre length 30, i.e. electrical conductor fibre weft 30, and optionally property modifying fibres, e.g. non-conductive fibre wefts 40 and/or fibre wefts 70 with mechanical, electromagnetic and/or thermal properties, inserted into the grid, is increased (e.g. by a factor of 4), this may enable the mat to be used to form more products, for example it may enable the basis of four identical products. After the forming (e.g. winding) of the electromagnetic mat is performed, the stator or rotor component may in a simple manner be cut from the formed mat/sheet, e.g. by cutting in the longitudinal direction of the electromagnetic mat 10. This may be scaled up to as many products as wanted.

(85) FIGS. 16A-16C show a method suitable for continuous winding fibres 30, e.g. electrical conductor fibre wefts 30. The pattern of the winding fibres 30 is provided by means of twining. In this embodiment at least two structural fibre lengths 20, e.g. warps 20 with non-conductive surface (and possibly fibre warps with mechanical, electromagnetic and/or thermal properties) form a grid (i.e. support structure) that is stretched out between a cylindrical object 50 (i.e. base 50) and a feeder assembly 80. A twining assembly 90 is positioned around the grid formed by the structural fibres 20, which is arranged to rotate around the grid. The twining assembly 90 is arranged to lay out continuous winding fibres 30 in a desired pattern around the grid. Similar to the embodiments above the mechanical, electromagnetic and/or thermal properties may be altered. For example all continuous winding fibres 30 from all phases A, B, C (e.g. 3) may be wound at the same time. This may for example be achieved if the winding fibres are arranged in a thin, flat, tape-format, as shown in FIG. 16B. In this embodiment the continuous winding fibres 30, i.e. electrical conductor fibre wefts 30, are arranged on the grid formed by the structural fibres 20, i.e. fibre warps 20 with non-conductive surface (and possibly fibre warps with mechanical, electromagnetic and/or thermal properties), at the same time as the electromagnetic mat 10 is rolled-up on the cylindrical object 50, e.g. base 50. Alternatively the resulting electromagnetic mat 10 may be folded. This production method results in a zig-zag, skewed, or tilted, winding pattern, as shown in FIG. 16C. Benefits of this design are that end-windings and harmonics may be reduced, which may result in lower weight and higher efficiency.

(86) Also this embodiment can make use of the intermediate step of impregnation and final step of molding. This embodiment may also be adapted for the use of discrete winding fibre lengths 30, e.g. cut electrical conductor fibre wefts 30, but this will require attachment of the discrete winding fibre lengths 30 to the grid of structural fibres 20 e.g. fibre warps 20 with non-conductive surface (and possibly fibre warps with mechanical, electromagnetic and/or thermal properties) e.g. by the tape, by impregnation or some other suitable means.

(87) This embodiment may benefit from the advantages of the prior described embodiments, including the design of the pattern of the winding fibres, e.g. electrical conductor fibre wefts, geometry, connection of the winding fibres, and the use of discrete or continuous winding fibres, e.g. cut or continuous electrical conductor fibre wefts.

(88) As for the other embodiments property modifying fibres can be incorporated, e.g. fibre warps and/or fibre wefts with mechanical, electromagnetic and/or thermal properties can be utilized. For example iron fibre wefts 70 may be used to create tilted or skewed iron teeth. Iron fibre warps or wefts 70 may also be used to create back iron (e.g. in the case where the first, or last, part of the electromagnetic mat 10 is pure or mainly iron).

(89) The electromagnetic mat 10 may further be provided with other objects, such as magnets or pipes. For example the electromagnetic mat 10 may be provided with water pipes for improved cooling properties.

(90) In a further modification, the method may further comprise forming, e.g. weaving, twining or winding, a mat without winding fibres, e.g. a mat with non-conductive wefts and/or wefts with other mechanical, electromagnetic and/or thermal properties and warps with electromagnetic, mechanical and/or thermal properties and/or warps with conductive properties. For instance, a mat without conductive fibres but with electromagnetic, mechanical and/or thermal properties could be created and used as part of a rotor or stator component to enhance properties. For instance, mats of mentioned properties could be plied or formed by rolling or folding on rotor or stator components, either on top, under, or between layers with conductive properties, i.e. layers with the winding fibres. For instance, these mats may have flux carrying or thermally conductive properties and be applied to the outer or inner surface of a rotor or stator component. This may be as part of the production process of the electromagnetic mat with winding fibres or in a separate step before or after the production of the electromagnetic mat with winding fibres.

(91) The following section sets out an exemplary slotless electric motor that was designed and manufactured using an electromagnetic mat to form the windings. Whilst it should be appreciated that the stator and rotor can be constructed in a variety of ways, one exemplary stator was formed in the following way.

(92) A plurality of structural fibres 20 were threaded in a customized loom. A tension was applied per structural fibre 20, with the tension varying between the structural fibres 20. The outermost structural fibres 20 (the distance between which is the active area) were placed parallel with a number of structural fibres in parallel in the active area between the two outermost structural fibres. One end of each structural fibre was connected to a cylindrical base. The width of the base was equal to the active width of the electromagnetic mat 10. The outer diameter of the base was equal to the desired inner diameter of the stator.

(93) The base was attached to a rotor by which it could be turned, so as to roll up the connected structural fibres 20 (and hence electromagnetic mat 10) onto the base.

(94) The base had in this example two main purposes, 1) to act as a mold for the electromagnetic mat 10 so it can be shaped into a radial flux stator component, and 2) function as a flux leader (i.e. back-iron) in the stator.

(95) Winding fibres 30 were inserted in the structural fibre lengths to form the electromagnetic mat. The winding fibres 30 were inserted at the wire insertion region of the loom in a three phase winding pattern. The winding fibres 30 were locked in place in a plain-weave pattern by the structural fibres 20, so to create a three phase distributed winding pattern, with one winding fibre 30 per shed. Continuous winding fibres 30 were used and which were woven into the structural fibres using shuttles.

(96) The electromagnetic mat 10 was formed by rolling up the woven electromagnetic mat onto the base to form a plurality of layers. Each layer had a plurality of poles and the poles had an angular width of 360/(the number of poles) degrees. Each layer where thus of different/increasing lengths with an increased distance between the winding fibre lengths so that each pole was placed exactly in its respective slot, i.e. aligned with the other winding fibre lengths. The structural fibres extending out of the electromagnetic mat 10 were cut. The free ends of the structural fibers 20 were stitched to the rolled up electromagnetic mat to prevent it from unraveling. The rolled up electromagnetic mat was then molded with a resin and hardener, and cured. The end of the winding fibres extending out from the molded stator, were then connected to a circuit board in the desired parallel/series combinations.

(97) The above described embodiments and examples can be combined and modified to form other embodiments and examples which are within the scope of the invention as defined by the claims.