DE102023127956A1 - Stator for an electrical machine - Google Patents

Abstract

A stator (1, 1') for an electrical machine (2) comprises: a first plate (10A), a second plate (10B), an electrical coil (11) running between the first plate (10A) and the second plate (10B), a first holding part (12A) and a second holding part (12B), which are each fastened to the first plate (10A) and to the second plate (10B) and between which the coil (11) is held, wherein at least one of the holding parts (12A, 12B) is designed and/or arranged asymmetrically with respect to a center line (M1) running between the plates (10A, 10B).

Description

The present disclosure relates in particular to a stator for an electric machine, to an electric machine, to a vehicle having such an electric machine and to a method for producing a stator.

For electric motors and other electrical machines, the goal is to continually improve the target parameters of energy efficiency, power-to-weight ratio, reliability, and service life. Furthermore, electrical machines should have the lowest possible failure rate and a long service life. At the same time, it is desirable to manufacture electrical machines as simply and reliably as possible. These objectives are sometimes in conflict with one another.

The task is to make an electrical machine as easy to manufacture as possible.

According to one aspect, a stator for an electrical machine is provided. The stator comprises a first plate, a second plate, an electrical coil extending between the first plate and the second plate, a first holding part, and a second holding part, which are each fastened to the first plate and to the second plate and between which the coil is held. Provision is made for at least one of the holding parts to be designed and/or arranged asymmetrically with respect to a center line extending between the plates.

This is based on the realization that the manufacture of an electrical machine can be significantly simplified, since the described arrangement allows for easier assembly of the plates with the holding parts. DE 10 2022 109 871 A1 For example, an electrical machine is described which comprises C-shaped holding parts which enclose the coil on both sides. The holding parts are arranged symmetrically with respect to a center line between the plates and enable the coil to be held symmetrically centered between the plates. However, inserting the holding parts into openings in the plates is laborious and takes a relatively long time. The solution proposed here allows for simplified assembly and thus shorter production times. The center line runs, for example, parallel to the plates. The center line runs, for example, within a center plane which runs parallel to the plates and in the middle between the plates. At least one of the holding parts is, for example, also designed and/or arranged asymmetrically with respect to the center plane. The holding parts can simultaneously serve as iron cores of the electrical machine and thus fulfill a dual function.

Both retaining parts can be designed and/or arranged asymmetrically with respect to the centerline, further simplifying manufacturing.

One or both of the holding parts has/have (each) a first section and a second section that run at an angle to each other. The sections are therefore not parallel to each other. The angle is, for example, an obtuse angle. This allows the coil to be securely enclosed.

For example, the two plates run parallel to each other. The first section of one of the retaining parts, or the respective first section of both retaining parts, can be aligned perpendicular to the plates. This allows for particularly simple, straight insertion during production.

The first section of one of the retaining parts, or the respective first section of both retaining parts, can extend beyond the centerline. This allows the coil to be securely held centered between the plates.

The first section of the first retaining part can be inserted vertically into an opening in the second plate. Furthermore, the first section of the second retaining part can be inserted vertically into an opening in the first plate. This allows for easy, straight-line insertion during manufacturing.

The holding parts can be identical in design or mirror-imaged to each other. This allows for particularly simple production of a large number of holding parts, which is particularly important because the stator can comprise a plurality of first and second holding parts.

For example, the holding parts are each L-shaped or V-shaped. This allows for both easy assembly and secure mounting of the coil.

The holding parts can grip the coil in sections to securely lock the coil.

A square, particularly diamond-shaped, free space is formed between the holding parts. The coil can be arranged in this free space. This shape of the free space allows the coil to be fixed in all directions perpendicular to the coil.

The stator may comprise a plurality of pairs of first and second retaining members. This allows the coil to be securely held along its length.

The stator may further comprise a third plate, a fourth plate, a further electrical coil running between the third plate and the fourth plate, a third holding part and a fourth holding part, which are each fastened to the third plate and to the fourth plate, and between which the further coil is held. Provision may be made for at least one of the third and fourth holding parts to be designed and/or arranged asymmetrically with respect to a center line running between the third and fourth plates, and/or for at least one of the third and fourth holding parts to be inserted vertically into an opening in one of the third and fourth plates. The further coil can be operated independently of the first-mentioned coil, so that the electrical machine with the stator is still operational even if one of the two coils fails.

The four plates can all be arranged parallel to one another. Furthermore, the four plates can all be offset from one another along an axial direction. The axial direction corresponds, for example, to the rotational axis of a rotor mounted on the stator. The shape of the stator determines this rotational axis. The four plates are all arranged at different positions along the axial direction, for example. This allows for a compact design.

According to one aspect, a stator for an electrical machine is provided, in particular according to any of the embodiments described above. The stator comprises a first plate, a second plate, an electrical coil extending between the first plate and the second plate, a first holding part and a second holding part, which are respectively fastened to the first plate and to the second plate, and between which the coil is held, wherein at least one of the holding parts is inserted vertically into an opening in one of the plates. With regard to the advantages, reference is made to the above information.

According to one aspect, an electric machine is provided, e.g., for a vehicle, in particular for an aircraft. The electric machine comprises a stator according to any of the embodiments described herein and a rotor rotatable relative to the stator.

The rotor may surround the stator externally. The electric machine may therefore be an external rotor. Alternatively, the electric machine may be designed as an internal rotor.

The electric machine can be designed as a transverse flux machine, alternatively as an axial flux machine, or as a radial flux machine. A transverse flux machine allows for a low installation height and relatively low speeds while simultaneously delivering high torque.

The rotor can be configured to drive a propeller (or be driven by a propeller). The electric motor is, for example, an aircraft engine.

According to one aspect, a vehicle, in particular an aircraft, is specified, comprising the electric machine according to any of the embodiments described herein.

According to one aspect, a method for producing a stator, in particular according to any of the embodiments described herein, is specified. The method comprises providing a first plate to which a first holding part is fastened and which has an opening; providing a second plate to which a second holding part is fastened and which has an opening; arranging an electrical coil on the first holding part or on the second holding part; and moving the first plate in a straight line towards the second plate until the first holding part is inserted into the opening of the second plate and the second holding part is inserted into the opening of the first plate. The stator can thus be produced in a particularly simple manner.

• 1 ein Luftfahrzeug mit mehreren elektrischen Maschinen zum Antrieb mehrerer Propeller;
• 2 eine aufgeschnittene Ansicht einer der elektrischen Maschinen des Luftfahrzeugs gemäß 1 mit einem Stator und einem Rotor;
• 3 einen Teil des Stators der elektrischen Maschine gemäß 2;
• 4 Platten und Halteteile des Stators gemäß 3 in einer schematischen Seitenansicht;
• 5 einen Teil eines Stators für die elektrische Maschine gemäß 2;
• 6 Platten und Halteteile des Stators gemäß 5 in einer schematischen Seitenansicht; und
• 7 ein Verfahren zur Herstellung eines Stators.

Embodiments will now be described by way of example with reference to the figures, in which:

• 1 an aircraft with several electric machines for driving several propellers;
• 2 a cutaway view of one of the aircraft's electrical machines according to 1 with a stator and a rotor;
• 3 a part of the stator of the electrical machine according to 2 ;
• 4 Plates and holding parts of the stator according to 3 in a schematic side view;
• 5 a part of a stator for the electrical machine according to 2 ;
• 6 Plates and holding parts of the stator according to 5 in a schematic side view; and
• 7 a method for manufacturing a stator.

1 shows an aircraft 3 in the form of an air taxi. The aircraft 2 comprises a cabin 30 and several, here four, electrical machines 2, each in the form of an electric motor. Each of the electrical machines 2 drives a propeller 21. For this purpose, each of the propellers 21 is operatively connected to a rotor of the respective electrical machine 2 (e.g., attached thereto). A battery 31 supplies electrical current to operate the electrical machines 2. The electrical machines 2 in this case are direct drives.

2 illustrates the basic structure of the example according to 1 electrical machines of the same design 2.

The electric machine 2 comprises a stator 1 and a rotor 20 which is rotatable about a rotational axis D relative to the stator 1. The rotor 20 is rotatably mounted on the stator by means of bearings 22, here in the form of ball bearings, alternatively e.g. plain bearings. The electric machine 2 is designed here, for example, as an external rotor. The rotor 20 surrounds the stator 1. The stator 1 is arranged within the rotor 20. The stator 1 can be mounted on a supporting structure of the aircraft 3 by means of a fastening region 14, here in the form of a flange, and in the state according to 1 mounted.

The rotor 20 comprises a shaft flange 200, to which a shaft can be mounted and in the state according to 1 is mounted. The rotor 20 then drives the propeller 21 via the shaft.

The stator 1 further comprises a base 15. The base 15 comprises holders 150 on which coils of the stator 1 are mounted (these are shown in 2 not shown for the sake of simplicity, but instead shown separately in 3 illustrated.

As in 3 As can be seen, the stator of the electric machine 2 comprises a first plate 10A and a second plate 10B. The first plate 10A and the second plate 10B are flat and aligned parallel to one another. The first and second plates 10A, 10B are spaced apart from one another. An electrical coil 11 runs between the first plate 10A and the second plate 10B. When the coil 11 is energized, a magnetic field is created which interacts with permanent magnets of the rotor 20 and thus causes the rotor 20 to rotate relative to the stator 1.

The stator 1 further comprises a first holding part 12A and a second holding part 12B, which are respectively fastened to the first plate 10A and to the second plate 10B. In the example shown, the first plate 10A has openings 100, 102, here for example in the form of through-openings, into which the holding parts 12A, 12B are each inserted. The wide plate 10B also has openings 101, 103, here also for example in the form of through-openings, into which the holding parts 12A, 12B are each inserted. One end of a respective holding part 12A, 12B is thus inserted into one plate 10A, 10B and the other end of the holding parts 12A, 12B is inserted into the other plate 10A, 10B. For example, the holding parts 12A, 12B are welded to the plates 10A, 10B in the openings 100-103.

The holding parts 12A, 12B each extend from the first plate 10A to the second plate 10B. The holding parts 12A, 12B are each engaged with the first plate 10A and the second plate 10B.

The holding parts 12A, 12B are made of iron, for example. The holding parts 12A, 12B can comprise or consist of a ferromagnetic metal alloy. The holding parts 12A, 12B can also be referred to as iron cores or magnetic cores. The holding parts 12A, 12B are in the form of holding webs. In this case, the holding parts 12A, 12B form an inductance together with the coil 11. The holding parts 12A, 12B conduct the magnetic flux of the coil 11. Thus, the holding parts 12A, 12B have two functions: an electromagnetic one and a mechanical one, namely the holding of the coil 11. The holding parts 12A, 12B are made of sheet metal.

The coil 11 is held between the plates 10A, 10B by means of the holding parts 12A, 12B. The plates 10A, 10B are similar or identical to each other.

The windings of coil 11, located radially closer to the rotational axis D, run concentrically one-third of a circle around the rotational axis D, are then wound radially outwards and run radially further away from the rotational axis D back concentrically one-third of a circle around the rotational axis D. The coil 11 is then supplied with one of the three phases of a rotary phase alternating voltage. Three such phase units are arranged in a circle in the stator 1. This enables an efficient and flat construction. The plates 10A, 10B each describe a part of a circular disk. In the present case, the plates 10A, 10B, of which 3 a cutaway view is shown, each one third of a circular disk.

The radially inner winding part of the coil 11 is enclosed by several pairs of the described holding parts 12A, 12B. The electrical The conductor of the coil 11 is encapsulated in a potting compound 16, which is in contact with the holding parts 12A, 12B. The radially outer winding part of the coil 11 is also enclosed by several pairs of the described holding parts 12A, 12B. There, too, the electrical conductor of the coil 11 is encapsulated in a potting compound 16, which is in contact with the corresponding holding parts 12A, 12B.

Viewed in the circumferential direction around the rotation axis D, the first and second holding parts 12A, 12B alternate. The first and second holding parts 12A, 12B are arranged offset from one another in the circumferential direction.

With reference to 4 Further details of stator 1 will now be explained.

In the present case, it is provided that at least one of the holding parts 12A, 12B is designed and arranged asymmetrically with respect to a center line M1 running between the plates 10A, 10B. 4 It can be seen that both holding parts 12A, 12B are designed and arranged asymmetrically with respect to the center line M1 running between the plates 10A, 10B. The holding parts 12A, 12B are also arranged asymmetrically with respect to each of the plates 10A, 10B.

In the present case, both holding parts 12A, 12B are designed as identical parts and are mounted with the reverse orientation between the plates 10A, 10B.

The holding parts 12A, 12B each have a first section 120 and a second section 121. The respective first section 120 and the respective second section 121 are at an angle α of more than 90 degrees and less than 180 degrees to each other, in particular an angle of between 100 and 170 degrees. Here, an angle α of (approximately) 120 degrees is provided as an example.

The respective first section 120 extends from the respective plate 10A, 10B perpendicularly thereto. The respective first section 120 extends from the respective plate 10A, 10B beyond the center line M1. The center line M1 runs parallel to the plates 10A, 10B and halfway between them. The respective first section 120 therefore crosses the center line M1 at a right angle.

The respective first section 120 is just inserted into the respective opening 100, 101 of the corresponding plate 10A, 10B.

The respective second section 121 is inserted into the opening 102, 103 made in the plate at an angle to the surface of the respective plate 10A, 10B.

The respective first section 120 and the respective second section 120 are each linear and are connected to each other via a bend. The holding parts 12A, 12B are V-shaped in this case, with the obtuse angle α, but could alternatively also be L-shaped.

A diamond-shaped free space is formed between the holding parts 12A, 12B, in which the respective section of the coil 11 is arranged, wherein the holding parts 12A, 12B each encompass the coil 11 in sections.

5 illustrates a stator 1' which is constructed similarly to the stator 1 described above, with four plates 10A-10D being provided instead of two.

The first and second plates 10A, 10B, with the coil 11 held therebetween by the holding parts 12A, 12B, are designed as described above. A further electrical coil 13 is arranged between a third plate 10C and a fourth plate 10D and is held by a plurality of pairs each consisting of a third holding part 12C and a fourth holding part 12D. The unit comprising the third and fourth plates 10C, 10D, the further coil 13, and the third and fourth holding parts 12C, 12D is arranged in this case as a mirror image of the unit comprising the first and second plates 10A, 10B, the coil 11, and the first and second holding parts 12A, 12B.

Accordingly, it is provided that the third and fourth holding parts 12C, 12D are designed and arranged asymmetrically with respect to a center line M2 running between the third and fourth plates 10C, 10D and that the third and fourth holding parts 12C, 12D are each inserted vertically into an opening 100, 101 in one of the third and fourth plates 10C, 10D.

Mountings 201 are provided on the rotor 20', on which permanent magnets 202 arranged in rings are mounted. The permanent magnets 202 face the respective plates 10A-10D, so that a current flow in the coils 11, 13 causes the rotor 20' to rotate. In the case of the stator 1 according to 2-4 Permanent magnets arranged in rings are also mounted on the rotor 20 holders, but not in four planes as in 5 shown, but only in two.

5 further illustrates an inverter 23 of the electric machine with the stator 1' and the rotor 20'. The inverter 23 is e.g. electrically connected to the battery 31 and has two inverter units 230A, 230B. One of the inverter units 230A, 230B supplies the coil 11 (and two other phase units located in the same plane) with current (one phase of a three-phase alternating current). The other of the inverter units 230A, 230B supplies the further coil 13 (and two other phase units located in the same plane) with current (one phase of a three-phase alternating current).

6 illustrates the arrangement of the holding parts 12A-12D relative to the plates 10A-10D. The third and fourth holding parts 12C, 12D are arranged mirror-inverted (with respect to a plane perpendicular to the third and fourth plates 10C, 10D) compared to the first and second holding parts 12A, 12B. This allows a balanced torque to be achieved for the inclined diamond shape.

Alternatively, the third and fourth holding parts 12C, 12D are not mirror images, but are inclined in the other direction from the vertical (towards the respective plate 10C, 10D).

The four plates 10A-10D are all arranged parallel to each other and all offset from each other along an axial direction parallel to the axis of rotation D.

7 illustrates a method for producing a stator 1, 1', in particular one of the stators 1, 1' described above.

The method comprises the following steps, which may be performed in a different order than specified, or alternatively in exactly the order specified.

Providing a first plate 10A, to which a first holding part 10A is attached and which has an opening 100, and a second plate 10B, to which a second holding part 10B is attached and which has an opening 101; arranging an electrical coil 11 on the first holding part 12A or on the second holding part 12B; and moving the first plate 10A straight towards the second plate 10B (see the arrow in 7 ) until the first holding part 12A is inserted into the opening 101 of the second plate 10B and the second holding part 12B is inserted into the opening 100 of the first plate 10A.

The described design allows for straight insertion, which prevents damage to the encapsulation 16 or even the coil 11, 13 during assembly. Furthermore, this enables simple and quick installation.

It should be understood that the disclosure is not limited to the embodiments described above, and various modifications and improvements may be made without departing from the concepts described herein. Any of the features may be employed separately or in combination with any other features, provided they are not mutually exclusive, and the disclosure extends to and encompasses all combinations and subcombinations of one or more of the features described herein.

List of reference symbols

1, 1'

stator

10A-10D

first, second, third, fourth plate

100-103

opening

11

Sink

12A-12D

first, second, third, fourth holding part

120

first section

121

second section

13

additional coil

14

Mounting area

15

base

150

bracket

16

Casting

2

electric machine

20, 20'

rotor

200

Shaft flange

201

bracket

202

permanent magnet

21

propeller

22

warehouse

23

Inverter

230A, 230B

Inverter unit

3

aircraft

30

cabin

31

battery

α

angle

D

axis of rotation

M1, M2

center line

QUOTES CONTAINED IN THE DESCRIPTION

This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 10 2022 109 871 A1 [0005]

Claims (20)

Stator (1, 1') for an electrical machine (2), comprising: - a first plate (10A), - a second plate (10B), - an electrical coil (11) extending between the first plate (10A) and the second plate (10B), - a first holding part (12A) and a second holding part (12B), which are respectively fastened to the first plate (10A) and to the second plate (10B) and between which the coil (11) is held, wherein at least one of the holding parts (12A, 12B) is designed and/or arranged asymmetrically with respect to a center line (M1) extending between the plates (10A, 10B). Stator (1, 1') after Claim 1 , wherein both holding parts (12A, 12B) are designed and/or arranged asymmetrically with respect to the center line (M1). Stator (1, 1') after Claim 1 or 2 , wherein the holding parts (12A, 12B) each have a first section (120) and a second section (121) which extend at an angle (α) to one another. Stator (1, 1') after Claim 3 , wherein the two plates (10A, 10B) run parallel to each other and the respective first section (120) is aligned perpendicular to the plates (10A, 10B). Stator (1, 1') after Claim 3 or 4 , wherein the respective first section (120) extends beyond the center line (M1). Stator (1, 1') according to one of the Claims 3 until 5 , wherein the first portion (120) of the first holding part (12A) is inserted vertically into an opening (101) in the second plate (10B) and the first portion (120) of the second holding part (12B) is inserted vertically into an opening (100) in the first plate (10A). Stator (1, 1') according to one of the preceding claims, wherein the holding parts (12A, 12B) are of identical construction or are mirror-inverted to one another. Stator (1, 1') according to one of the preceding claims, wherein the holding parts (12A, 12B) are each L-shaped or V-shaped. Stator (1, 1') according to one of the preceding claims, wherein the holding parts (12A, 12B) each encompass the coil (11) in sections. Stator (1, 1') according to one of the preceding claims, wherein a diamond-shaped free space is formed between the holding parts (12A, 12B), in which the coil (11) is arranged. Stator (1, 1') according to one of the preceding claims, comprising a plurality of pairs each comprising a first holding part (12A) and a second holding part (12B). Stator (1') according to one of the preceding claims, further comprising: - a third plate (10C), - a fourth plate (10D), - a further electrical coil (13) extending between the third plate (10C) and the fourth plate (10D), - a third holding part (12C) and a fourth holding part (12D), which are respectively fastened to the third plate (10C) and to the fourth plate (10D), and between which the further coil (13) is held, wherein at least one of the third and fourth holding parts (12C, 12D) is designed and/or arranged asymmetrically with respect to a center line (M2) extending between the third and fourth plates (10C, 10D), and/or wherein at least one of the third and fourth holding parts (12C, 12D) is inserted perpendicularly into an opening (100, 101) in one of the third and fourth plates (10C, 10D). Stator (1, 1') after Claim 12 , wherein the four plates (10A-10D) are arranged parallel to each other and all offset from each other along an axial direction. Stator (1, 1') for an electrical machine (2), in particular according to one of the preceding claims, comprising: - a first plate (10A), - a second plate (10B), - an electrical coil (11) extending between the first plate (10A) and the second plate (10B), - a first holding part (12A) and a second holding part (12B), which are respectively fastened to the first plate (10A) and to the second plate (10B), and between which the coil (11) is held, wherein at least one of the holding parts (12A, 12B) is inserted vertically into an opening (100, 101) in one of the plates (10A, 10B). An electrical machine (2) comprising: - a stator (1, 1') according to one of the preceding claims and - a rotor (20, 20') rotatable relative to the stator (1, 1'). Electrical machine (2) according to Claim 15 , wherein the rotor (20, 20') surrounds the stator (1, 1') on the outside. Electrical machine (2) according to Claim 15 or 16 , designed in the form of a transverse flux machine. Electrical machine (2) according to one of the Claims 15 until 17 , wherein the rotor (20, 20') drives a propeller (21). Vehicle, in particular aircraft (3), comprising the electric machine (2) according to one of the Claims 15 until 18 . Method for producing a stator (1, 1'), in particular according to one of the Claims 1 until 14 , comprising: - providing a first plate (10A) to which a first holding part (10A) is fastened and which has an opening (100); - providing a second plate (10B) to which a second holding part (10B) is fastened and which has an opening (101); - arranging an electrical coil (11) on the first holding part (12A) or on the second holding part (12B); and - moving the first plate (10A) in a straight line towards the second plate (10B) until the first holding part (12A) is inserted into the opening (101) of the second plate (10B) and the second holding part (12B) is inserted into the opening (100) of the first plate (10A).

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