DE102022002673A1 - Method for adjusting a magnetic property of a pole plate for an electrical machine, as well as pole plate and electrical machine - Google Patents

Abstract

The invention relates to a method for adapting a magnetic property of a pole plate (6) for an electrical machine (1), wherein - the pole plate (6) is formed in one piece and has two pole shoe sections (8) with a pole tooth section (7) in between, and - the two pole shoe sections (8) have a magnetic anisotropic material property, the following steps being carried out: - introducing thermal energy into at least a partial area (12) of at least one of the two pole shoe sections (8), and - converting the magnetically anisotropic material property of the partial area (12 ) of the at least one pole piece section (8) into a magnetic isotropic material property depending on the thermal energy introduced. The invention further relates to a pole plate (6) and an electrical machine (1).

Description

The invention relates to a method for adjusting a magnetic property of a pole plate for an electrical machine.

The invention further relates to a pole plate for an electrical pole of an electrical machine. The invention further relates to an electrical machine with a stack of pole plates.

Electrical machines, especially rotating electrical machines, can be used in a wide variety of demanding technical applications. For example, electrical machines play a central role in the automotive industry, especially when used in motor vehicles.

The use of electric machines as drive units or as traction motors in company vehicles or in electric vehicles is particularly important.

Electric machines mainly consist of a rotor and a stator. The stator can be constructed from a large number of individual teeth or stator teeth. Such a single tooth or stator tooth consists, for example, of a pole core and two pole shoes.

Measures for influencing the properties of materials for magnetic field guidance are known in the prior art. Materials can be combined with each other in a variety of ways, as is the case, for example EP 23 96 874 A1 is known. Furthermore, this influence can be carried out using mechanical stress or mechanical changes. This is for example in the DE 10 2015 013 447 A1 known.

Furthermore, from the DE 10 2014 208 866 A1 a heat-treated rotor for an electrical machine excited by permanent magnets is known. An axial area can be created by heat treating the laminated core.

Such electrical machines and their individual components of the prior art have an inhomogeneity in terms of their magnetic properties, which can have a negative effect on the efficiency of the electrical machine.

Therefore, an object of the present invention is to process a pole plate or several pole plates of an electrical machine in such a way that in particular the iron losses or total iron losses of the electrical machine can be reduced.

This task is solved by a method, a pole plate and an electrical machine according to the independent patent claims. Useful further training results from the dependent patent claims.

• - das Polblech einteilig gebildet ist und zwei Polschuhabschnitte mit einem dazwischenliegenden Polzahnabschnitt aufweist, und
• - die zwei Polschuhabschnitte eine magnetische anisotrope Materialeigenschaft aufweisen, wobei folgende Schritte durchgeführt werden:
• - Einbringen einer thermischen Energie in zumindest einen Teilbereich zumindest eines der beiden Polschuhabschnitte, und
• - Umwandeln der magnetisch anisotropen Materialeigenschaft des Teilbereichs des zumindest einen Polschuhabschnitts in eine magnetische isotrope Materialeigenschaft abhängig von der eingebrachten thermischen Energie.

One aspect of the invention relates to a method for adjusting a magnetic property of a pole plate for an electrical machine, wherein

• - the pole plate is formed in one piece and has two pole shoe sections with a pole tooth section in between, and
• - the two pole shoe sections have a magnetic anisotropic material property, the following steps being carried out:
• - Introducing thermal energy into at least a portion of at least one of the two pole shoe sections, and
• - Converting the magnetically anisotropic material property of the portion of the at least one pole piece section into a magnetic isotropic material property depending on the thermal energy introduced.

With the proposed method, the pole plate and in particular all pole plates of an electrical machine can be adapted or changed or processed in such a way that the iron losses or the total losses of the electrical machine can be reduced. This has the advantage, especially when using the electric machine in an electrically powered vehicle, that the electric range of the vehicle can be increased and the electric machine, which serves, for example, as the drive unit of the vehicle, can achieve higher performance. This is achieved primarily by modifying the pole plate, particularly locally. Furthermore, by converting the magnetically anisotropic material property of the partial area into a magnetically isotropic material property, a local modification of the material in this partial area can take place. As a result, the material property, in particular the magnetic material property, can be influenced in such a way that when the electrical machine is operating, a magnetic flux can be homogenized in the overall structure of the electrical machine and in particular in this sub-area. In this way, hotspots in particular, i.e. areas that cause negative magnetic properties or interference, can be minimized. The total losses and in particular the total iron losses of the electrical machine can thus be reduced.

Using the proposed method, magnetization behavior of the electrical machine can be optimized to make it less susceptible to operational influences, such as speed requirements and/or torque requirements of the electrical machine. In particular, the proposed method can be used to locally adapt or change a magnetic property, a magnetic material property, a material property and/or a magnetic flux of a pole plate.

Through the one-piece or integrally formed pole plate, which can be formed from a material or an electrical sheet, a pole tooth can be formed in such a way that it can be manufactured more efficiently and causes lower manufacturing costs.

The pole plate can be a pole plate of a pole tooth or a pole element or a stator tooth. This means that a pole tooth or an individual tooth of the electrical machine can be formed, especially by stacking several pole plates.

The pole plate can, for example, be manufactured simultaneously from one material or one material in a manufacturing step or a manufacturing process step. The pole tooth section can be, for example, a sheet metal cut or a partial cut of a pole tooth or a pole tooth core or a pole tooth base body. The pole sections are individual cuts or sheet metal cuts from pole pieces of the pole tooth. A pole tooth of the electrical machine can be formed by a stack of several pole plates. With the help of a pole tooth, an electrical pole of the electrical machine can be provided or formed.

The two pole shoe sections have a base material that has a magnetically anisotropic material property. For example, an electrical sheet can be used for this. In particular, soft magnetic materials can be used. The magnetically anisotropic material property can be a grain-oriented property. The two pole shoe sections can therefore be designed as a grain-oriented electrical sheet.

A magnetic anisotropic material property can be understood as a direction-independent material behavior. A pronounced crystallographic texture can be present here, so that a preferred magnetic direction in the rolling direction can be specified. Accordingly, such an anisotropic material property and thus the two pole sections have a lower power loss in the preferred direction. Above all, there is a homogeneous distribution of the grain structure. For example, a grain size there can be larger than 1000 micrometers. The sheet metal thickness of the pole piece sections can optionally be between 0.1 and 0.3 millimeters. In particular, the two pole shoe sections can therefore have very good properties in one direction, in particular in the rolling direction.

By introducing or applying or generating the thermal energy, which can in particular be a specifically predetermined thermal energy, such as a specific heat input, the magnetic material property of the at least one partial area can be changed. In particular, the thermal energy can occur during a manufacturing process of the pole sheet or after a manufacturing process. In particular, the partial area can be an area in a respective pole shoe section which has a negative magnetic property. By introducing the thermal energy into the at least one subregion or into several subregions, which can be, for example, an outer area of the pole plate or a magnetic hotspot of the pole plate, the magnetically anisotropic material property of the subregion can be converted or modified or manipulated into a magnetically isotropic material property.

The isotropic material property is a direction-independent material behavior in this sub-area. Thus, after the conversion, the partial area can now be a non-grain-oriented electrical sheet or a non-grain-oriented electrical sheet section. Such an isotropic material property can be defined in such a way that the respective area or material area has a non-crystallographic texture and therefore this sub-area does not have a preferred magnetic direction. Furthermore, after the transformation into the partial area, there is an irregular distribution of the grain structure. This converted portion can have a grain size of 60 micrometers to 200 micrometers. The sheet thickness remains unchanged, for example between 0.1 and 0.3 millimeters.

In other words, a local modification of soft magnetic structures in the pole sheets can be carried out using the proposed method. Accordingly The electrical machine can have areas that have a local, targeted, location-dependent isotropy. In particular, an anisotropic sheet or pole sheet can be locally modified, so that this sheet, which is anisotropic in itself, has an isotropic property in some areas. This means that the magnetic flux can be improved, especially when the pole plate is later used in the electrical machine.

In one exemplary embodiment it is provided that the thermal energy is introduced by means of a heat treatment process. In particular, with the help of the heat treatment process, a targeted, in particular specific, introduction of thermal energy takes place. A local heat treatment of the partial area can therefore be carried out. In particular, a wide variety of heat treatment processes can be applied or used. Above all, the thermal energy can be introduced, in particular exclusively, into at least one partial area using special tools. This makes it possible to ensure that, above all, only the partial area to be converted is exposed to this special thermal energy or heat.

Above all, with the help of the heat treatment process, a local introduction of temperature, in particular depending on a predetermined temperature value, can be carried out into at least a partial area.

In a further exemplary embodiment it is provided that laser texturing or uniform laser irradiation takes place during a heat treatment process. The at least one partial area can thus be specifically thermally processed or modified, so that a conversion from the anisotropic material property to the isotropic material property can be brought about within the partial area. For example, laser texturing can be laser structuring. Above all, a laser can be used to provide uniform laser irradiation, so that at least one partial area can be processed evenly. Laser-based heat treatment takes place here using laser radiation.

In one exemplary embodiment it is further provided that the thermal energy is introduced during a manufacturing process of the pole sheet or as a post-processing process immediately following the manufacturing process. Thus, the magnetic material properties can be changed or locally adjusted in the at least one predetermined partial area either during the manufacturing process or the production of the pole plate. Likewise, the conversion of the magnetic material properties of the partial area can take place in particular immediately, i.e. directly following the manufacturing process of the pole plate.

It is also conceivable that each pole plate or each plate layer of the pole tooth is thermally processed individually or that the pole tooth formed by stacking the pole plates is thermally processed as a whole in the respective areas.

In one exemplary embodiment it is further provided that a texture within the at least one partial area is changed depending on the thermal energy introduced. Thus, the conversion of the grain-oriented sheet metal area into a non-grain-oriented sheet metal area within the partial area can be caused or generated here. Thus, the nature or the material quality, in particular a surface quality, and above all a crystalline structure of the at least one partial area can be manipulated or changed, so that a magnetically isotropic material property is formed within the at least one partial area.

Thus, a homogeneous texture of a base material of at least one partial area can be generated here, so that a magnetic flux can be optimized, especially in the at least one partial area, and thus the proportion of magnetic material flowing through can be increased, so that, above all, in operation of the electrical Machine losses, especially iron losses, decrease.

In one exemplary embodiment it is further provided that the thermal energy is introduced at least in a transition region of the at least one partial region which extends between the pole tooth section and one of the two pole shoe sections. Above all, areas that have a transition between elements have negative magnetic properties. Above all, edges and/or corners are a reason for poor magnetic flux and therefore poor magnetic properties. This can occur especially in the H-shaped and, above all, one-piece pole plate in the transition area between the pole tooth section and the outer pole shoe sections. The at least one partial area can therefore have a transition between the pole shoe section and one of the two pole shoe sections. In this transition area The magnetic properties can be particularly poor, so that the magnetically anisotropic material property should be converted into a magnetically isotropic material property. Thus, the magnetic properties of the pole plate can be specifically processed or adjusted in local areas that have or cause negative magnetic properties.

A further aspect of the invention relates to a pole plate for an electrical pole of an electrical machine, wherein the pole plate is formed in one piece and has two pole shoe sections with a pole tooth section in between. The two pole shoe sections have a magnetically anisotropic or grain-oriented material property. The pole plate has at least a predetermined partial area of at least one of the two pole shoe sections, which has a magnetically anisotropic material property, which is generated by converting the magnetically anisotropic material property of the partial area depending on the introduction of thermal energy into at least one predetermined partial area.

In particular, the pole plate just shown can be processed or adapted using a method according to the previous aspect or an advantageous development thereof. Thus, the method according to the previous aspect or an advantageous development thereof can be used to adapt a magnetic property of the pole plate.

In particular, the proposed pole plate can be a pole plate layer or a sheet metal layer or a sheet metal cut of a pole tooth or pole element. In particular, an electrical pole of the electrical machine can be provided with the aid of the pole tooth.

In particular, the pole plate can be a locally modified soft magnetic plate, which serves to improve a magnetic flux in a component of an electromotive drive unit, in particular the electric machine.

In an exemplary embodiment of the further aspect, it is provided that the pole plate is designed as an electrical sheet, in particular as a cobalt-iron sheet or as a nickel-iron sheet. In particular, the pole plate can be made from an electrical sheet or from a soft magnetic material. In particular, the electrical sheet is formed from an iron-based material.

In a further exemplary embodiment of the further aspect, it is provided that the electrical sheet has silicon, aluminum and/or manganese as an alloy component. In particular, depending on the application of the pole sheet and in particular the electrical machine, the respective material composition or material composition of the electrical sheet can be adjusted. In particular, the electrical sheet can have at least 0.5 percent silicon, in particular at least one percent silicon, as an alloy component. Above all, the electrical sheet can have at least 0.5% by weight of silicon. Further alloying elements can also be provided.

For example, the electrical sheet can be in the form of cobalt iron sheet (CoFe) with a cobalt content of at least 10 percent. It is also conceivable that the iron-based material, in particular the electrical sheet, is in the form of nickel-iron sheet (NiFe) with a nickel content of at least 10 percent. These material composition examples mentioned are not intended to be exhaustive, but are only intended to provide a small insight into the possible material compositions with regard to the electrical sheet. Other materials or substances, particularly for use in electrical machines, are also conceivable.

A further aspect of the invention relates to an electrical machine, in particular an axial flux machine, with a stack of pole plates according to the previous aspect or an advantageous development. In particular, the electrical machine has a large number of pole teeth. For example, the electrical machine can have a stator, so that this stator has a large number of pole teeth or stator teeth.

For example, the electrical machine can be a three-phase alternating current machine such as an asynchronous machine or a synchronous machine. In particular, the electric machine is a three-phase machine, which can be used for an electric traction drive of an electrically operated vehicle. For example, the electrical machine can be a transverse flux machine.

Since the electrical machine according to the invention can be used primarily in the automotive industry, the electrical machine can be designed specifically as an axial flux machine. Such an axial flux machine has a high level of efficiency over a wide speed range, which is particularly important in the area of driving vehicle traction is advantageous. Such an axial flux machine can have, for example, a disk-shaped stator, which is formed from a large number of pole teeth or stator teeth. Here, the pole plate according to the invention, from which a pole tooth can be formed, can be made, for example, from a powder composite material.

In particular, the pole tooth can have a plurality of pole plates stacked one above the other or arranged one above the other. The pole tooth therefore consists of a large number of pole plates, each of which is formed in one piece. In particular, a pole plate according to the previous aspect can be used to be able to form a corresponding pole tooth. The pole tooth thus has a sheet metal arrangement, i.e. a stacking of individual pole sheets or pole sheet sections. Accordingly, in a sectional view, the pole tooth each has a corresponding, one-piece pole plate.

For example, the pole tooth according to the invention can be used as a single tooth for a rotor or a stator. Accordingly, at least one pole tooth according to the invention or several such pole teeth can be used for electrical machines. In particular, the pole tooth according to the invention can be a stator tooth of a stator of an axial flux machine.

In particular, the pole tooth can be formed by packaging or sheet metal packaging of individual pole plates according to the previous aspect.

By means of the pole tooth according to the invention, an electrical machine, in particular an axial flux machine, can be produced with minimal effort and, in particular, with reduced costs. The pole tooth can therefore be produced cost-effectively in the simplest manner, in particular through a process involving the packaging of the pole sheets.

Accordingly, the pole tooth has a respective cut through the stack or the stacking of the pole sheets, which has, for example, an H-shape of the pole shoe sections formed in one piece with one another and of the pole tooth section. Accordingly, each sheet metal layer or each pole plate of the pole tooth has a one-piece unit and, above all, the respective pole plate or a respective sheet metal layer of the pole tooth is made from one and the same material, in particular in one processing step.

With the help of the pole tooth or a pole element, an electrical pole of the electrical machine, in particular an axial flux machine, can be provided or created.

The pole tooth has two opposite pole pieces, between which a winding to be carried by the pole tooth can be arranged. The stack of pole plates simultaneously forms a pole tooth base body or a pole tooth core and the two pole pieces. The pole tooth base body can therefore be formed by the pole tooth sections stacked on top of one another. The two pole pieces can be formed by the pole piece sections stacked on top of each other.

Advantageous developments of one aspect of the present invention can be viewed as advantageous developments of another aspect and/or all other aspects. This also applies in reverse.

In particular, the pole plate and/or the electrical machine can have, in particular technical, means to carry out or carry out the method according to the invention.

Advantageous embodiments of the method are to be viewed as advantageous embodiments of the electrical machine and the. Advantageous embodiments of the electrical machine or the pole plate can also be viewed as advantageous embodiments of the method.

Further advantages, features and details of the invention result from the following description of preferred exemplary embodiments and from the drawing(s). The features and feature combinations mentioned above in the description as well as the features and feature combinations mentioned below in the description of the figures and/or shown in the figures alone can be used not only in the combination specified in each case, but also in other combinations or on their own, without the scope of the invention to leave.

• 1 eine schematische Darstellung einer elektrischen Maschine;
• 2 eine schematische Darstellung eines Polzahns der elektrischen Maschine aus 1, wobei der Polzahn anhand mehrerer Polblech gebildet ist;
• 3 eine schematische Darstellung eines Polblechs des Polzahns aus 2;
• 4 eine schematische Darstellung eines Polzahnabschnitts des Polblechs aus 3;
• 5 eine schematische Darstellung von Polschuhabschnitten des Polblechs aus 3;
• 6 ein beispielhafter Prozessschritt für ein Einbringen einer thermischen Energie in einen Teilbereich eines Polblechs; und
• 7 ein weiterer beispielhafter Prozessschritt für ein Einbringen einer thermischen Energie in einen fertig gebildeten Polzahn.

The following figures show:

• 1 a schematic representation of an electrical machine;
• 2 a schematic representation of a pole tooth of the electrical machine 1 , whereby the pole tooth is formed using several pole plates;
• 3 a schematic representation of a pole plate of the pole tooth 2 ;
• 4 a schematic representation of a pole tooth section of the pole plate 3 ;
• 5 a schematic representation of pole shoe sections of the pole plate 3 ;
• 6 an exemplary process step for introducing thermal energy into a portion of a pole plate; and
• 7 another exemplary process step for introducing thermal energy into a fully formed pole tooth.

In the figures, functionally identical elements are provided with the same reference numbers.

In the 1 a schematic representation of an electrical machine 1 is shown. This electrical machine 1 can be a three-phase machine, in particular for use in electrically powered vehicles. Other types of electrical machines are also conceivable embodiments.

The electrical machine 1 can have, for example, a stator and a rotor. In particular, the electrical machine 1 is rotatable with respect to an axis of rotation 2. An axial direction A can be predetermined in the direction of the rotation axis 2, which extends in particular through the center of the electrical machine 1. The axial direction A thus extends corresponding to the axis of rotation 2. The electrical machine 1 has a radial direction R perpendicular to this axial direction A.

Furthermore, the electrical machine 1 can have a circumferential direction U. This runs, for example, according to the circumference of the electrical machine 1 and in particular according to the stator or rotor.

The electrical machine 1 can have a pole tooth 3, for example. This can be, for example, a single tooth or a stator tooth. The at least one pole tooth 3 or further pole teeth 4 can be arranged accordingly in the circumferential direction U, in particular in a ring shape.

In the 2 A schematic representation of the pole tooth 3 is now shown. A sectional view of the pole tooth 3 is shown here as an example.

So that the pole tooth 3 can be manufactured as cost-effectively and, above all, efficiently, especially in a manufacturing process, it can be made from a stack of several pole plates 5 (cf. 1 ) be educated. The pole tooth 3 is therefore formed from several stacked sheet metal layers or electrical sheets. Furthermore, in normal operation of the pole tooth 3 as a component of the electrical machine 1, the same reference for the pole tooth with respect to the radial direction R and the axial direction A corresponds.

The special design of the sheet metal layers 4 sheet metal layers 5 on a sheet metal layer 6 is explained below. This applies to all sheet metal layers or pole plates 5 of the pole tooth 3.

The pole plate 6 has a pole tooth section 7 and two opposite pole shoe sections 8, between which the pole tooth section 7 is arranged. The pole shoe sections 8 and the pole tooth section 7 can be designed or formed as a one-piece or one-piece unit. The pole plate 6 can therefore be referred to as a one-piece element or unit. The pole tooth 3 thus consists of an arrangement of one-piece or one-piece pole plates 5, 6.

As an example in the 2 shown, the pole plate 6 can have an H-shape. This is primarily due to the fact that both the pole tooth section 7 and the pole shoe sections 8 are formed as a one-piece unit or are designed as a one-piece unit.

Above all, both pole shoes 9 and a pole tooth base body 10 can be formed at the same time by the stack of pole plates 5, 6, especially in one processing step. By stacking the pole sheets 5, 6 together, the pole tooth base body 10 or a pole tooth core can be formed by the pole tooth sections 7 stacked together. The two pole shoes 9, which are arranged opposite one another between the pole tooth base body 10, can be formed by the pole shoe sections 8 stacked together or adjacent to one another. Thus, for example, the pole tooth 3 of the electrical machine 1 can be manufactured directly from a sheet metal package. This has the main advantage over the prior art that in the prior art the pole tooth base body 10 and then the pole pieces 9 are manufactured first. The assembly is done there, for example, by gluing.

For example, each of the pole plates 5, 6 can be designed as an electrical sheet. The pole plates 5, 6 or the pole plate 6 therefore consist, for example, of a soft magnetic material. In one embodiment, the pole can Sheet 6 can be formed from a stack or an adjacent arrangement of sheet metal layers or electrical sheets.

Furthermore, a width of the pole tooth 3 in the axial direction A can be constant. Thus, a respective width in the axial direction A of each pole plate 5, 6 can be the same or identical. Furthermore, as for example in the 2 You can see the stack of pole plates 5, 6, which form the pole tooth 3, in a wedge shape or wedge-shaped. This is a possible embodiment.

The pole tooth 3 thus has a wedge shape. A width of this formed wedge shape or the pole tooth 3 can in turn increase or widen outwards in the radial direction R. This means that the width of the wedge shape or the pole tooth 3 can become wider radially outwards. The pole tooth 3 is therefore narrower in its area which extends radially inwards than the areas which extend radially outwards. In particular, the width 15 is a width of the pole tooth 3 with respect to the circumferential direction U.

Accordingly, for example, a complete single tooth or pole tooth 3 for an electrical machine 1 can be produced or manufactured from an electrical sheet.

For this purpose, the pole tooth 3 in particular can be manufactured in such a way that both pole shoes 9 and a pole tooth base body 10 are formed by the stack of pole plates 5 at the same time.

Viewed in the axial direction A, the pole base body 10 is located between the two plate-like pole pieces 9.

In particular, the pole tooth 3 can be produced by stamping. Above all, the pole tooth base body 10 and the pole shoes 9 can be manufactured in a laminated core.

For example, the pole core or the pole tooth base body 10 as well as the two pole shoes 9 can be constructed together using an electrical sheet or another soft magnetic material. The pole sheets 5 can be tiled to form the pole tooth 3, for example by baking or welding.

In the 3 a schematic representation of the pole plate 6 is shown. The pole plate 6 can have a main flow direction 11, for example. This can be directed essentially perpendicular to the axial direction A.

Through the one-piece pole plate 6, from which the pole tooth 3 can be formed, an integrated design with respect to the pole tooth 3 or an integrated pole piece can be achieved. This one-piece design with respect to the pole plate 6 results in the main advantage that the pole tooth base body 10 does not have to be glued to the pole shoes 9, as in the prior art. As a result of the bonding or the adhesive, a corresponding pole tooth has an air gap or an air gap insulation, so that this leads to a disruption of the magnetic flux in the cross-sectional transition between the pole tooth base body 10 and the pole shoe 9. This can be prevented or reduced by the pole plate 6 according to the invention, since the one-piece structure of the pole plate 6 means that there is no air gap between the pole tooth section 7 and the pole shoe sections 8. Accordingly, a grain-oriented laminated core for the pole tooth 3 can be produced here. Above all, the pole plate 6 can have a highly inhomogeneous structure and have a pronounced texture, which, for example, has a grain size greater than one millimeter. The pole plate 6 can therefore have an anisotropic material as the base material. Above all, the pole shoe sections 8 have a magnetically anisotropic material property. In order to be able to design the pole plate 6 with better magnetic properties and thus also the electrical machine 1, the pole plate 6, which is inherently anisotropic, can be modified in such a way that it becomes at least locally isotropic in relevant cross-sectional areas.

In order to be able to adapt or change the magnetic properties and in particular a magnetic flux of the pole plate 6, the inherently magnetically anisotropic material property can be converted into a magnetically isotropic material property in places or areas that cause negative magnetic properties. For this purpose, in at least one partial area 12 (see 6 ) a thermal energy, in particular a specific, predetermined and / or directed thermal energy, can be introduced into this subarea 12. In particular, this at least one partial area 12 can be present in at least one of the two pole pieces 8. It is also conceivable that each pole piece section 8 has a respective partial area whose material properties can be changed.

By introducing the thermal energy in this way, the magnetically anisotropic material property of the partial region 12 can be converted into a magnetically isotropic material property. The inner or The middle area, i.e. the pole tooth section 7, remains untreated. The pole tooth section 7 in particular therefore has a directional magnetic guide. In the outer areas, i.e. in the at least a partial area 12 of the pole shoe sections 8, an isotropic material property can be created by heat treatment or structuring, so that there is a non-directional flow direction there.

In particular, the pole tooth section 7 has a directional orientation 13 (cf 4 ) and the pole shoe sections 8 have a non-directional orientation 14 (see 5 ) on.

In particular, the thermal energy can be introduced by means of a heat treatment process, such as laser texturing or uniform laser treatment. Here, the thermal energy can be generated in a manufacturing process of the pole plate 6 by means of a laser 15 (see 6 ) are introduced. Such treatment or processing of a respective pole plate 6 is, for example, in 6 shown. It is also conceivable that after the pole tooth 3 has been produced, in particular as a laminated core, the heat input or the heat treatment is carried out. This is for example in the 7 shown.

In particular, the introduction of thermal energy can take place directly as an intermediate step in the production of the individual pole plate 6 or the pole plates 5. Otherwise, this can be done after the pole tooth 3 has been manufactured or only at the end when the stator or electrical machine 1 has been produced. Thus, depending on the process step relating to the production of the pole sheet or the pole tooth 3, a process step can be introduced as heat treatment or laser texturing.

In this way, a flux-optimized stator can be created for an axial flux machine.

What is particularly important is the introduction of the thermal energy into at least one transition region 16 or a hotspot of the at least one partial region 12. This transition region 16 extends in particular between the pole tooth section 7 and the two pole shoe sections 8. Above all, negative magnetic properties or disturbance variables can be present there . This transition region 16 can, above all, be converted into an area which has an isotropic material property. It can thus be achieved that magnetic flow can flow through the pole plate 6 evenly. In this way, the magnetic flux in particular can spread evenly in the pole plate 6.

Above all, depending on the thermal energy introduced, such as heat, a texture or condition within the at least one partial area 12 and in particular the entire partial area 12 can be changed or manipulated.

Because the pole plate 6, which is anisotropic in itself, is locally converted into isotropic areas, iron losses can be reduced. This is done in particular by manipulating the inherently anisotropic material of the pole plate 6 into local or targeted isotropic material areas.

Because the pole plate 6 has a grain-oriented sheet or electrical sheet as the base material or base, local manipulation of the texture of the inherently anisotropic material can be carried out in particularly critical cross-sectional areas, in particular in the transition area 16, so that the texture of the material in These critical cross-sectional areas can be made non-grain-oriented, i.e. isotropic.

Accordingly, an inherently anisotropic base material can be created locally isotropically. Accordingly, a homogeneous texture of the respective base material can be achieved, especially in areas of a cross-sectional transition, i.e. from a pole tooth section 7 to the pole shoe sections 8, so that a magnetic flux can be optimized locally and thus the proportion of magnetic material of the pole plate 6 that flows through can be increased . For example, with the help of the heat treatment process, the pole shoe sections 8 in particular can be processed as locally heat-treated zones, so that the texture there can be changed or manipulated.

By converting the magnetically anisotropic material property of the at least one partial region 12 into an isotropic material property, iron losses of the electrical machine 1 can be reduced. Furthermore, the electrical machine 1 in particular can have material behavior that is more independent of the operating point and thus has a more constant torque behavior. Furthermore, local hotspots can be minimized, which has a particularly positive effect on thermal management and/or NVH behavior (noise, vibration, harshness).

In particular, the thermal energy can be introduced, for example, during the cutting process relating to the production of the hollow sheet 6. Likewise, thermal energy or thermal energies can be introduced in serial sequence during this cutting process. It is also conceivable that the energy input takes place on the fully formed pole tooth 3 as downstream processes. This can be done, for example, by surface finishing of the pole pieces 9.

For example, the pole plate 6 can be designed as an electrical sheet, in particular as a cobalt-iron sheet or as a nickel-iron sheet. Here, the pole plate can have, for example, silicon, aluminum and/or manganese as an alloy component or alloy components.

In other words, a material of the iron core, i.e. the pole plate 6, can be modified locally according to requirements so that the magnetic flux within the pole plate 6 and thus the electrical machine 1 can be optimized or improved. For this purpose, a texture of the material, in particular within the partial region 12, can be modified or changed by means of local introduction of temperature, such as by means of local laser heat treatment or inductive heat treatment. Furthermore, the base material, in particular the material of the pole plate 6, can be structured locally in the relevant cross-sectional area, in particular in the transition area 16. This can be done, for example, using a laser or a mechanical method.

Accordingly, especially the outer area of the pole plate 6, i.e. the pole shoe sections 8, can be processed, so that an isotropic material can be locally made from an anisotropic material.

In other words, a method can be provided to be able to generate local isotropy in the outer area of a pole tooth 3 or a pole plate 6. In particular, the pole tooth section 7 or the central region of the pole plate 6, which forms the core of the pole plate 6, has a homogeneous magnetic field due to a core-aligned electrical sheet. To support this, in the outer area, i.e. in the areas of the pole shoe sections 8, a homogeneous magnetic field is eliminated by the conversion in order to make this inhomogeneous, so that at least some areas there are isotropic. Thus, the portion 12 may be non-core oriented after conversion. By means of the conversion process, which takes place with the help of the thermal energy input, the orientation of the cores or the homogeneity of the magnetic field can be broken up or changed or manipulated, especially in the outer area of the pole plate 6.

Accordingly, a local new core formation takes place in the partial area 12, in particular in the edge areas of the pole plate 6, so that the basic structure or the material there is homogenized there.

For example, the pole plate 6 can be referred to as a component of an electric motor drive unit, which has at least one soft magnetic sheet or which has a stack of soft magnetic sheets. There, at least one soft magnetic sheet can be at least largely grain-oriented in sections and have a microstructure or texture that deviates from the grain orientation in at least a second section. Such a soft magnetic sheet can be an iron-based material. The at least one second section, which has a structure that deviates from the grain-oriented one, may have been created by post-treatment of a previously grain-oriented electrical sheet. For this purpose, the non-grain-oriented structure can also be created by local, thermal aftertreatment. Local laser heat treatments can also be carried out here. For example, the pole plate 6 can be a component of a stator or an individual tooth of a stator. In particular, the pole plate 6 is used in electric motors, especially in axial flux machines. The pole tooth 3 can be, for example, a stator tooth of an axial flux machine, which is made from at least one grain-oriented pole plate 6 or electrical sheet or a stack of pole plates 6, 5.

In a conceivable further exemplary embodiment, a method for producing a pole plate 6 can be provided. A pole tooth 3 can have at least one pole plate 6 or a stack of pole plates 5, 6 and the at least one pole plate 6 is at least largely grain-oriented in sections and has a structure deviating from the grain orientation in at least one second section. Furthermore, the at least one section with a structure that deviates from the grain orientation can be created by preventing a previously at least largely grain-oriented sheet metal from being subjected to post-treatment, so that there is no or essentially no grain orientation there anymore. This can be done, for example, by post-treatment, such as local thermal after-treatment treatment, in particular laser heat treatment, can be used.

Reference symbol list

1

electric machine

2

Axis of rotation

3

pole tooth

4

another pole tooth

5

Pole plates

6

Pole plate

7

Pole tooth section

8th

Pole shoe sections

9

Pole shoes

10

Pole tooth base body

11

Main flow direction

12

Sub-area

13

directed orientation

14

non-directional orientation

15

Laser

16

Transition area

A

Axial direction

R

Radial direction

U

Circumferential direction

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The 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

• EP 2396874 A1 [0006]
• DE 102015013447 A1 [0006]
• DE 102014208866 A1 [0007]

Claims (10)

Method for adjusting a magnetic property of a pole plate (6) for an electrical machine (1), wherein - the pole plate (6) is formed in one piece and has two pole shoe sections (8) with an intermediate pole tooth section (7), and - the two pole shoe sections (8) have a magnetic anisotropic material property, the following steps being carried out: - Introducing thermal energy into at least a partial area (12) of at least one of the two pole shoe sections (8), and - Converting the magnetically anisotropic material property of the partial region (12) of the at least one pole piece section (8) into a magnetic isotropic material property depending on the thermal energy introduced. Procedure according to Claim 1 , whereby the thermal energy is introduced using a heat treatment process. Procedure according to Claim 2 , whereby laser texturing or uniform laser irradiation takes place during the heat treatment process. Method according to one of the preceding claims, wherein the thermal energy is introduced during a manufacturing process of the pole plate (6) or as a post-processing process immediately following the manufacturing process. Method according to one of the preceding claims, wherein a texture within the at least one partial region (12) is changed depending on the thermal energy introduced. Method according to one of the preceding claims, wherein the thermal energy is introduced at least into a transition region (16) of the at least one partial region (12), which extends between the pole tooth section (7) and one of the two pole shoe sections (8). Pole plate (6) for an electrical pole of an electrical machine (1), where - the pole plate (6) is formed in one piece and has two pole shoe sections (8) with an intermediate pole tooth section (7), and - The two pole shoe sections (8) have a magnetic anisotropic material property, wherein - at least one predetermined partial area (12) of at least one of the two pole shoe sections (8) has a magnetic isotropic material property, which is generated by converting the magnetic anisotropic material property of the partial area (12) depending on the introduction of thermal energy into the at least one predetermined partial area (12). is, has. pole plate (6). Claim 7 , which is designed as an electrical sheet, in particular as a cobalt-iron sheet or as a nickel-iron sheet. pole plate (6). Claim 8 , wherein the electrical sheet has silicon, aluminum and / or manganese as an alloy component. Electric machine (1) with a stack of pole plates (5, 6) according to one of the Claims 7 until 9 .

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