DE102022004616A1 - Stator for an axial flow machine and axial flow machine - Google Patents

Abstract

The invention relates to a stator (10) for an axial flow machine, with an annular core (12) which has recesses (16) on one of its axial end faces (S1, S2) which are open inwards and outwards in the radial direction of the stator (10), and with at least one winding (20) held on the core (12) which is formed by several conductors (22) formed separately from one another, wherein the respective conductor (22) viewed in a plane running perpendicular to the axial direction of the stator (10) forms a star-shaped or flower-shaped structure open in the circumferential direction (24) of the stator (10) with exactly three first turns (W1) running inwards in the radial direction of the stator (10) and exactly two second turns (W2) running outwards in the radial direction of the stator (10), wherein the conductors (22) are arranged offset from one another in the recesses (16) in the circumferential direction (24) of the stator (10). are.

Description

The invention relates to a stator for an axial flow machine according to the preamble of patent claim 1. Furthermore, the invention relates to an axial flow machine with at least one such stator.

Such a stator for an axial flow machine is, for example, already the EN 10 2021 124 995 A1 as known. The stator has an annular core which has recesses on at least one of its axial end faces. The recesses are open inwards and outwards in the radial direction of the stator. The stator also comprises at least one winding held on the core, which is formed by several conductors formed separately from one another.

The object of the present invention is to provide a stator for an axial flow machine and an axial flow machine with at least one such stator, so that a particularly simple manufacture of the stator and thus of the axial flow machine can be realized.

This object is achieved by a stator having the features of patent claim 1 and by an axial flow machine having the features of patent claim 4. Advantageous embodiments with expedient further developments of the invention are specified in the remaining claims.

In order to further develop a stator of the type specified in the preamble of claim 1 in such a way that a particularly simple and thus time- and cost-effective manufacture of the stator and thus of the axial flux machine can be realized, it is provided according to the invention that the respective conductor in itself, that is to say considered on its own, in a plane running perpendicular to the axial direction of the stator and thus of the annular core forms a star-shaped or flower-shaped, that is to say a star-shaped or flower-shaped structure open in the circumferential direction of the stator and thus of the annular core with exactly three first turns running inwards in the radial direction of the stator and exactly two second turns running outwards in the radial direction of the stator. The conductors, each designed as a solid body, are offset from one another in the circumferential direction of the rotor and are arranged in the recesses, which are designed as grooves and/or run in a straight line, for example, in such a way that first length regions of at least one first of the conductors running in the radial direction of the stator are arranged in first of the recesses, with at least two second recesses being arranged in the circumferential direction of the stator between each two adjacent first length regions of the at least one first conductor and being free of the at least one first conductor. In other words, the first conductor is not arranged in the second recesses, but rather the first conductor skips or overlaps the second recesses. In addition, it is provided that second length regions of at least one second of the conductors running in the radial direction of the stator, offset from the at least one first conductor, are each arranged in one of the second recesses, with at least one or exactly one of the first recesses being arranged in the circumferential direction of the stator between each two adjacent second length regions of the at least one second conductor and being free of the at least one second conductor. This means that the second conductor jumps over or overlaps at least one or exactly one of the first recesses, and is therefore not arranged in at least one or exactly one of the first recesses. It is also provided that in the circumferential direction of the stator, between the two adjacent second length regions of the at least one second conductor, at least one or exactly another of the second recesses is arranged and is free of the at least one second conductor, so that the second conductor also jumps over or overlaps the other of the second recesses, and is therefore not arranged in the other of the second recesses.

It has also been shown to be particularly advantageous if the core, also referred to as the carrier, is formed, in particular completely, by, in particular precisely, a spirally wound sheet metal strip, also simply referred to as a strip. The sheet metal strip is preferably designed in one piece, thus made from a single piece. As part of a method for producing the stator, for example, the sheet metal strip is wound around an imaginary winding axis and thus wound up to form the core. As a result, respective layers or plies of the sheet metal strip are arranged on top of one another in the radial direction of the stator and thus of the core, wherein the layers or plies of the sheet metal strip are preferably designed in one piece with one another, thus made from a single piece. In order to avoid, for example, undesired unwinding of the sheet metal strip, for example, respective ends of the sheet metal strip are connected to the rest of the sheet metal strip, in particular to one of the layers, in particular bonded, in particular welded. This allows a particularly simple and therefore time- and cost-effective production of the stator and thus of the axial flow machine as a whole.

The invention also includes an axial flux machine, i.e. an electrical machine designed as an axial flux machine and also referred to as an axial flux motor, wherein the axial flux machine according to the invention has at least one stator according to the invention. Advantages and advantageous embodiments of the stator according to the invention are to be regarded as advantages and advantageous embodiments of the axial flux machine according to the invention and vice versa.

The previous and following statements on the stator can be easily transferred to a rotor of an axial flow machine or to the axial flow machine mentioned above and vice versa. The axial flow machine has, for example, in a fully manufactured state, the stator and the rotor, which can be driven by means of the stator and can therefore be rotated about a machine axis of rotation relative to the stator. The axial flow machine is very preferably a high-voltage component whose electrical voltage, in particular electrical operating or nominal voltage, is preferably greater than 50 volts, in particular greater than 60 volts, and very preferably amounts to several hundred volts.

In particular, it is conceivable to equip a motor vehicle, also referred to simply as a vehicle and preferably designed as a motor vehicle, in particular as a passenger car, with the axial flow machine, so that the motor vehicle, which in its fully manufactured state has the axial flow machine, can be driven by means of the axial flow machine, in particular purely electrically. The motor vehicle is therefore preferably a hybrid vehicle or an electric vehicle, in particular a battery-electric vehicle (BEV).

The invention is based in particular on the following findings and considerations. Radial flux machines (RFM) dominate today for electric drives for vehicles designed, for example, as hybrid vehicles or electric vehicles, in particular battery-electric vehicles.

New types of axial flow machines (AFM) promise advantages in terms of performance, installation space, arrangement of components and weight, among other things. Previously known AFM concepts focus primarily on stator concepts with concentrated windings, but their large-scale implementation is hampered by major technological challenges in the manufacture of the laminated cores, the windings and their assembly. The compact design is a disadvantage for the required cooling of the system. Furthermore, AFM with concentrated windings show disadvantages in terms of their noise behavior, which is also referred to as NVH behavior. The stator according to the invention represents a solution for further development of an axial flow machine and its further application in automotive engineering. Stators in a so-called single-tooth design are known, in particular with a concentrated winding. Disadvantages here can be the noise behavior and the very complex manufacture of the stator laminated cores, since a lamination direction should run radially. Another disadvantage can be joining the individual teeth without metallic contact, i.e. complex gluing to plastic parts. Plastic parts limit the operating temperature or the long-term load capacity. Other disadvantages can be assembly and installation, which can be very complex and costly. Assembly tolerances can also be disadvantageous. The use of individual teeth with edgewise winding is also known. The resulting disadvantages can be: limited design freedom due to minimal bending radii, heavy stress on the wire insulation in corner areas (thinning when bending), complex bending with superimposed tensile force; in addition, increased losses occur due to the large cross-section (proximity effect). Distributed, parallel windings are also known, which are continuously wound, for example. Disadvantages here can be: difficult to automate due to long wire lengths.

The aforementioned problems and disadvantages can be avoided by the invention. In the invention, the core, also referred to as the stator package, is ring-shaped and thus a ring core, which can preferably be formed from the aforementioned, in particular continuously wound sheet metal strip. Thus, the core is in particular a sheet metal package. The recesses, for example designed as grooves, are introduced into the sheet metal strip before it is wound, in particular incrementally, for example by shearing or laser cutting, for example before the sheet metal strip is wound into the core so that it is wound up. The winding is formed, for example, from the several star- or flower-shaped bent conductors, which form, for example, respective wire coils. The respective conductor is designed, for example, as a flat wire or as a strand. Viewed in the circumferential direction of the stator, the conductors or wire coils have such a width that the respective conductor overlaps the respective recesses arranged between the adjacent radial length regions. The respective length regions running in the radial direction are also referred to as radial webs. In particular, the respective lengths areas in a straight line and in the radial direction of the stator. For example, in the recesses also referred to as slots or designed as slots, which are also referred to as stator slots, winding layers are stacked, which are formed, for example, by the conductors. An advantageous jump between the winding layers, also referred to as slot layers, is achieved, for example, by inserting or weaving them into one another, in particular the conductors. A simple form of an arrangement of the slot layers is, for example, a stack of individual winding mats, such as those formed by the conductors, whereby phases u, v and w can be formed, for example. An advantageous weaving of the star-shaped wire coil advantageously takes place in a spiralized state, i.e. respective starts and respective ends, in particular respective wire starts and respective wire ends of the conductors, are each pulled apart axially, for example, and the conductors forming, for example, a wire star or wire flower are twisted into one another and, for example, placed step by step over and/or under one another. This is followed by a joint movement of the conductors, which are designed as wire stars or form wire stars, into a shaft jig, from which they are then mounted into the core (stator package).

• - einzeln gebogene Wicklungslagen, vorteilhaft automatisierbar, stapelbar, lagerbar
• - Kern als Ringkernblechpaket, vorteilhaft automatisierbar, Backlackbeziehungsweise MO- oder GO-Material wählbar (keine Sinterbauteile), Kostenpotenzial
• - die Wicklung kann durch unterschiedliche Grundformgebungsverfahren dargestellt werden: Drahtbiegen: 3D-Druck und/oder thermisches Fügen (Schweißen/Löten) von Einzelelementen
• - Direktkühlung im Statorblech integrierbar, höhere Leistung, höhere Leistungsfähigkeit, dauerlastfähig

For this purpose, the recesses are open in the radial direction inwards and thus to an air gap of the axial flow machine. Advantageously, a slot insulation paper is first inserted and then the winding mat is inserted axially and compressed. Pole shoes can optionally be subsequently attached to teeth, whereby the winding can be axially fixed. Finally, for example, a stator assembly comprising the core and the winding is impregnated, in particular with a resin. The invention can achieve at least the following advantages:

• - individually bent winding layers, advantageously automatable, stackable, storable
• - Core as toroidal core sheet package, advantageously automatable, baking varnish or MO or GO material selectable (no sintered components), cost potential
• - the winding can be represented by different basic forming processes: Wire bending: 3D printing and/or thermal joining (welding/soldering) of individual elements
• - Direct cooling can be integrated into the stator sheet, higher performance, higher efficiency, capable of continuous load

Further advantages, features and details of the invention emerge from the following description of a preferred embodiment and from the drawing. The features and combinations of features mentioned above in the description as well as the features and combinations of features mentioned below in the description of the figures and/or shown alone in the figures can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the invention.

• 1 eine schematische Perspektivansicht eines Stators für eine Axialflussmaschine, insbesondere eines Kraftfahrzeugs;
• 2 eine schematische Vorderansicht des Stators;
• 3 ausschnittsweise eine weitere schematische Vorderansicht des Stators;
• 4 eine schematische Vorderansicht eines Leiters des Stators;
• 5 schematische Vorderansichten des Stators
• 6 ausschnittsweise eine schematische Schnittansicht der Axialflussmaschine;
• 7 ausschnittsweise eine weitere schematische Schnittansicht der Axialflussmaschine
• 8 ausschnittsweise schematische Schnittansichten der Axialflussmaschine; und
• 9 eine schematische Perspektivansicht des Stators.

The drawing shows in:

• 1 a schematic perspective view of a stator for an axial flux machine, in particular of a motor vehicle;
• 2 a schematic front view of the stator;
• 3 another schematic front view of the stator;
• 4 a schematic front view of a conductor of the stator;
• 5 schematic front views of the stator
• 6 a schematic sectional view of the axial flow machine;
• 7 another schematic sectional view of the axial flow machine
• 8th partial schematic sectional views of the axial flow machine; and
• 9 a schematic perspective view of the stator.

In the figures, identical or functionally identical elements are provided with identical reference symbols.

1 shows a schematic perspective view of a stator 10 for an axial flow machine, in particular of a motor vehicle. This means that the axial flow machine in its fully manufactured state has the stator 10 and, for example, also a rotor, which can be driven, for example, by means of the stator 10 and can thus be rotated about a machine axis of rotation relative to the stator. For example, the axial flow machine can provide drive torques via its rotor, by means of which the motor vehicle can be driven, in particular purely electrically. In particular, the previous and following statements on the stator 10 can also be easily transferred to the rotor and vice versa. For example, the stator 10 is a double stator, or the stator 10 is part of a double stator of the axial flow machine. Thus, it is It is conceivable that the said rotor of the axial flow machine is a double rotor of the axial flow machine, or that the said rotor is a component of a double rotor of the axial flow machine.

The stator 10 has an annular core 12, which is also referred to as a carrier or stator carrier. The core 12 is a laminated core which is formed, in particular completely, by, in particular precisely, a spirally wound sheet metal strip. This means that in a method for producing the stator 10, the sheet metal strip is wound around a particularly imaginary winding axis and is thereby wound up to form the core 12, wherein the imaginary winding axis runs, for example, in the axial direction of the stator 10 and thus of the axial flux machine, and thus coincides with the axial direction of the stator 10. It can be seen that the core 12 itself has a, in particular central, through-opening 14. The core 12 has recesses 16 on one of its axial end faces S1 and S2, which are mainly designed as grooves and are also referred to as stator grooves. 1 It can be seen that in the embodiment shown in the figures, the core 12 has the recesses 16 (grooves) on the axial end face S1. The respective recess 16 runs straight and in the radial direction of the stator 10 and thus of the axial flow machine. The respective recess 16 is in a direction parallel to the axial direction of the stator 10 and in 1 by an arrow 18. In addition, the respective recess 16 is open in the radial direction of the stator 10 inwards and thus towards the through opening 14 as well as outwards, in particular when considering the core 12 alone.

In conjunction with 2 it can be seen that the stator 10 also has at least one winding 20, which is formed separately from the core 12 and held on the core 12 and thus supported by the core 12. Particularly good in conjunction with 3 and 4 It can be seen that the winding 20 is formed by several conductors 22 which are formed separately from one another and are each formed as a solid body. One of the conductors 22 is in 3 and 4 shown.

In order to be able to realize a particularly simple and thus time- and cost-effective production of the stator 10 and thus of the axial flow machine as a whole, as in 3 and 4 As can be seen from the example of the conductor 22 shown there, the respective integrally formed conductor 22 is in itself in a direction perpendicular to the axial direction of the stator 10 and, for example, with the image plane of 2 , 3 and 4 coincident plane considers a flower-shaped structure, that is to say a flower-shaped and in this case flower-shaped curved structure, open in the circumferential direction of the stator 10 with exactly three first windings W1 running inwards in the radial direction of the stator 10 and exactly two second windings W2 running outwards in the radial direction of the stator 10. The circumferential direction of the stator 10 runs around the axial direction of the stator 10, the axial direction of which is perpendicular to the image plane of 3 and 4 In addition, the circumferential direction is illustrated by an arrow 24.

Out of 1 to 4 it can be seen that the conductors 22 are offset from one another in the circumferential direction of the stator 10 and are arranged in the recesses 16 in such a way that first length ranges L1 of at least one first of the conductors 22, which run in the radial direction of the stator 10, the radial direction of which runs perpendicular to the axial direction of the stator 10, are arranged in the first of the recesses 16. It can be seen that the respective conductor 22 has exactly six length ranges which run in a straight line and in the radial direction of the stator 10, namely the previously mentioned length ranges L1 in relation to the at least one first of the conductors 22. The length ranges are also referred to as radial webs. In the circumferential direction of the stator 10, between each two adjacent first length ranges L1 of the at least one first conductor 22, in the present case exactly two second of the recesses 16 are arranged, wherein the two second recesses 16 are free of the at least one first conductor 22. This means that the at least one first conductor 22, for example, in 3 is shown. Furthermore, it is provided that the second length region L2 of at least one of the conductors 22, which extends in the radial direction of the stator 10 and is offset from the at least one first conductor in the circumferential direction of the stator 10, is each arranged in one of the second recesses 16, wherein the at least one second conductor is arranged in 4 is shown. Furthermore, it is provided that in the circumferential direction of the stator 10 between each two adjacent second length regions L2 of the at least one second conductor 22, in the present case, exactly one of the first recesses is arranged and is free of the at least one second conductor, wherein in the circumferential direction of the stator 10 between each two adjacent second length regions L2 of the at least one second conductor, in the present case, exactly another of the second recesses is arranged and is free of the at least one second conductor 22.

The respective conductor 22 is, for example, a flat wire, so that the respective conductor 22 has, for example, a rectangular cross-section on the outer circumference. Furthermore, the respective conductor 22 can be a stranded wire, the cross-section of which can be round, in particular circular, on the outer circumference. The winding 20 can thus be designed as a flat wire winding.

Out of 5 it can be seen that the winding 20 and/or the respective conductor 22 can optionally have an S-bevel. For example, the multiple conductors 22 are arranged on top of one another in the stator slots in the axial direction of the stator 10, so that the conductor 22 forms, for example, layers or winding layers or mats or winding mats. An interweaving of the winding layers or winding mats can be provided, in particular in an advantageously spiral-shaped stretched or twisted state, in particular conductor 22. It is conceivable that pole shoes can be joined axially afterwards. A compressible stacking in the stator slots can be represented. A horizontal dripping and thus impregnation of the core 12 and/or the winding 20, in particular with resin, is possible. Alternatively or additionally, a scooping impregnation is conceivable. A connector function by extending and winding ends of the conductors 22, also referred to as wire ends, can be easily represented.

In 6 Two of the pole shoes are shown in detail and labelled 28. Also in 6 The winding 20, which is designed as a wave winding, can be seen in detail. 6 The core 12 designed as a stator laminated core is also shown.

In 7 It can be seen that the pole shoes 28 can be at least partially embedded in a mat 30, for example, wherein the mat 30 is formed from a carbon fiber reinforced plastic (CFRP). 8th shows partial sectional views of the axial flow machine. Finally, in 9 the stator 10 is shown in a schematic perspective view.

List of reference symbols

10

stator

12

core

14

Passage opening

16

Recess

18

Arrow

20

Winding

22

Director

24

Arrow

26

Sloped roof

28

Pole shoe

30

mat

L1

first length range

L2

second length range

S1

axial face

S2

axial face

W1

first turn

W2

second turn

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely to provide the reader with better information. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• DE 102021124995 A1 [0002]

Claims (4)

Stator (10) for an axial flow machine, with an annular core (12) which has recesses (16) on at least one of its axial end faces (S1, S2) which are open inwards and outwards in the radial direction of the stator (10), and with at least one winding (20) held on the core (12) which is formed by several conductors (22) formed separately from one another, characterized in that the respective conductor (22) as viewed in a plane running perpendicular to the axial direction of the stator (10) forms a star-shaped or flower-shaped structure which is open in the circumferential direction (24) of the stator (10) with exactly three first turns (W1) running inwards in the radial direction of the stator (10) and exactly two second turns (W2) running outwards in the radial direction of the stator (10), wherein the conductors (22) are offset from one another in the circumferential direction (24) of the stator (10) and in the recesses in such a way (16) are arranged such that: - first length regions (L1) of at least one first of the conductors (22), which run in the radial direction of the stator (10), are arranged in first of the recesses (16), wherein in the circumferential direction (24) of the stator (10) between each two adjacent first length regions (L1) of the at least one first conductor (22), at least or exactly two second of the recesses (16) are arranged and are free of the at least one first conductor (22); and - second length regions (L2) of at least one second conductor (22) arranged in the circumferential direction (24) of the stator (10) offset from the at least one first conductor (22) are each arranged in one of the second recesses (16), wherein in the circumferential direction (24) of the stator (10) between each two adjacent second length regions (L2) of the at least one second conductor (22) at least or exactly one of the first recesses (16) is arranged and free of the at least one second conductor (22), and wherein in the circumferential direction (24) of the stator (10) between each two adjacent second length regions (L2) of the at least one second conductor (22) at least or exactly one other of the second recesses (16) is arranged and free of the at least one second conductor (22). Stator (10) after Claim 1 , characterized in that the core (12) is formed by a spirally wound sheet metal strip. Stator (10) after Claim 1 or 2 , characterized in that the conductors (22) are inserted into one another and/or woven together. Axial flux machine, with at least one stator (10) according to one of the preceding claims.

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