Method for manufacturing a magnetic support, magnetic support, electrical machine with a magnetic support

Abstract

Method for manufacturing a magnetic carrier (MT) for an electric machine, comprising the following steps: - Providing a sheet metal stack (BP) with at least one recess (AN) for receiving at least one magnetic element (ME); - Providing at least one magnetic element (ME); - Providing at least one magnetic element (ME) with at least one elastic retaining element (HE) on its circumference; - Inserting the at least one magnetic element (ME) into the at least one recess (AN) after the at least one magnetic element (ME) has been provided with the at least one elastic retaining element (HE); - wherein the at least one magnetic element (ME) is provided with at least two retaining elements (HE), wherein the at least two retaining elements (HE) are arranged spatially separated from each other on the circumference of the at least one magnetic element (ME) and hold the at least one magnetic element (ME) in the at least one recess (AN); - wherein at least one insulating element (IE) is arranged on the circumference of the at least one magnetic element (ME) before the magnetic element (ME) is inserted into the recess, so that the insulating element (IE) is physically firmly connected to the magnetic element (ME), wherein the at least one insulating element (IE) electrically insulates the at least one magnetic element (ME) from the laminated core (BP), and the at least one insulating element (IE) and the at least one retaining element (HE) are formed integrally, wherein the retaining element (HE) is adapted to a contour of an inner wall (IW) of the recess (AN) by means of an elastic deformation.

Description

Technical area:

[0001] The invention relates to a method for producing a magnet carrier for an electrical machine. Furthermore, the invention relates to a magnet carrier for an electrical machine, as well as to an electrical machine, in particular a permanent-magnet synchronous machine, having such a magnet carrier. State of the art:

[0002] Electrical machines, especially permanent-magnet synchronous machines, comprise a stator and a rotor, with the stator and rotor, respectively, comprising a magnet carrier. The magnet carrier, in turn, comprises a laminated core with permanent magnets attached to or within it. These permanent magnets are made of brittle sintered magnets and are therefore brittle and fragile.

[0003] Due to the brittle nature and magnetic force of permanent magnets, attaching them to or within the laminated core is complex and costly in terms of manufacturing. Furthermore, permanent magnets are easily broken during operation of electrical machines due to strong vibrations and centrifugal forces.

[0004] DE 10 2011 119 512 A1 describes a method for producing a rotor for a permanent magnet electrical machine in which magnets are coated with an expandable adhesive.

[0005] DE 10 2012 016 927 A1 describes a rotor of an electric machine with permanent magnets arranged therein, as well as an assembly method. The assembly method for fixing a permanent magnet in a recess of a rotor provides for a permanent magnet to be inserted into the recess together with at least one clamping element arranged in a first direction of extension of the permanent magnet.

[0006] An object of the present invention is to show a possibility of producing magnetic carriers and thus also electrical machines more simply and cost-effectively. Description of the invention:

[0007] This problem is solved by the subject matter of the independent claims. Advantageous embodiments are the subject matter of the dependent claims.

[0008] According to a first aspect of the invention, a method for producing a magnet carrier for an electrical machine is provided.

[0009] According to the method, a laminated core with at least one recess is provided, wherein the at least one recess is designed to accommodate at least one magnetic element. Furthermore, at least one magnetic element is provided. The at least one magnetic element is provided with at least one elastic retaining element on its circumference. After being provided with the at least one elastic retaining element, the at least one magnetic element is then inserted into the at least one recess together with the at least one elastic retaining element.

[0010] A magnet carrier is a laminated core with built-in magnetic elements that will form a stator or rotor, or parts thereof, or a stator or rotor itself that comprises a laminated core with built-in magnetic elements. Depending on the perspective, a magnet carrier is thus an intermediate or final product of a stator or rotor of an electrical machine, especially a permanent magnet synchronous machine.

[0011] A recess means a groove-shaped depression (such as a dovetail groove) on the outer circumference of the laminated core or a through or blind hole in the laminated core in which at least one magnetic element is arranged and fastened.

[0012] The magnetic element can be a (fully magnetized) permanent magnet, for example, containing a hard magnetic material. Alternatively, the magnetic element can also be a (not yet fully magnetized) magnetizable element, for example, made of a magnetizable hard magnetic material, which can only be (fully) magnetized once it is arranged or secured in the recess.

[0013] The holding element is attached to the circumference of the magnetic element and is thus physically firmly connected to the magnetic element before the magnetic element is inserted into the corresponding recess. Due to its elasticity, the holding element is soft and spring-elastic. When the magnetic element together with the holding element is inserted into the recess, the holding element deforms, adapting to the contour of the opening of the recess and thus facilitating insertion. Due to this deformation, the holding element also allows the magnetic element to be inserted into the recess with a low pressing force. Furthermore, the holding element compensates for the compressive forces acting on the magnetic element and the holding element during insertion, thus protecting the magnetic element from deformation or breakage when inserted into the recess.

[0014] Thanks to its elasticity, the retaining element holds the magnetic element softly and resiliently in the recess, compensating for vibrations or centrifugal forces acting on the magnetic element during operation of the electrical machine. This protects the magnetic element from deformation or breakage even during operation of the electrical machine. At the same time, the retaining element holds the magnetic element firmly in the recess, preventing it from slipping out of the recess during operation of the electrical machine.

[0015] This demonstrates a possibility of producing magnetic carriers or electrical machines more easily and cost-effectively, while also being stable.

[0016] The retaining element preferably contains an elastomer. The elastomer can be applied in liquid form to the circumference of the magnetic element by overmolding. Alternatively, an elastomer in powder form can be applied to the circumference of the magnetic element by fluidized-bed sintering. Alternatively, the retaining element can be applied to the circumference of the magnetic element in a dipping process in the form of a liquid elastomer. After hardening or after melting and subsequent hardening, the elastomer forms the aforementioned retaining element. Alternatively, the retaining element is designed as an extruded profile, which can be easily and cost-effectively manufactured from an elastomer in an extrusion process and attached or glued to the circumference of the magnetic element.

[0017] Preferably, the at least one magnetic element is only magnetized after it has been inserted into the at least one recess together with the at least one holding element.

[0018] For this purpose, the magnetic element is made of a magnetizable material, which becomes magnetizable through subsequent magnetization. The magnetization of the magnetic element occurs, for example, by the (repeated) application of a magnetic field to the magnetic element.

[0019] According to the invention, the at least one magnetic element is provided with at least two retaining elements, wherein the at least two retaining elements are arranged spatially separated from one another on the circumference of the at least one magnetic element. After inserting the at least one magnetic element together with the at least two retaining elements into the at least one recess, these retaining elements hold the at least one magnetic element firmly in the at least one recess.

[0020] When inserting the magnetic element together with the retaining elements into the recess, the at least two retaining elements maintain the distance between the magnetic element and the hard inner wall of the recess or the laminated core, thus preventing the magnetic element from colliding with the laminated core and breaking. After insertion into the recess, the retaining elements, which are spatially separated from each other and distributed between the magnetic element and the inner wall of the recess, softly and resiliently fix the magnetic element in the center of the recess from two or more sides.

[0021] According to the invention, the at least one magnetic element is provided on the circumference with at least one insulating element, wherein the at least one insulating element electrically insulates the at least one magnetic element (after insertion into the at least one recess) from the laminated core.

[0022] Preferably, the at least one magnetic element, together with the at least one insulating element, is inserted into the at least one recess after the at least one magnetic element has been provided with the at least one insulating element. The insulating element is attached to the periphery of the magnetic element and is thus physically firmly connected to the magnetic element before the magnetic element is inserted into the recess.

[0023] According to the invention, the at least one insulating element and the at least one holding element are formed integrally with one another.

[0024] Preferably, the insulating element and the holding element(s) consist of one and the same elastic and dielectric material, such as one and the same dielectric elastomer, and are formed on the magnetic element in one and the same injection or injection molding process, fluidized bed sintering or dipping process.

[0025] According to a further aspect of the invention, a magnet carrier for an electrical machine, in particular a permanent magnet synchronous machine, is provided.

[0026] The magnet carrier comprises a laminated core with at least one recess configured to receive at least one magnetic element. Furthermore, the magnet carrier comprises at least one magnetic element arranged in the at least one recess. Furthermore, the magnet carrier comprises at least one elastic retaining element arranged on the periphery of the at least one magnetic element and securing the at least one magnetic element in the at least one recess. The at least one magnetic element, together with the at least one elastic retaining element, is inserted into the at least one recess after the at least one magnetic element has been provided with the at least one elastic retaining element.

[0027] The at least one magnetic element is preferably only magnetized after it has been inserted into the at least one recess together with the at least one elastic holding element.

[0028] The magnet carrier preferably comprises at least two holding elements, which are arranged spatially separated from one another along the circumference of the at least one magnetic element and are inserted into the at least one recess together with the at least one magnetic element. In the at least one recess, the at least two holding elements are thus spatially separated from one another between the inner wall of the at least one recess and the at least one magnetic element, and thus jointly hold the at least one magnetic element in the at least one recess at at least two fastening points.

[0029] Preferably, the magnet carrier further comprises at least one insulating element which is arranged on the circumference of the at least one magnet element and electrically insulates the at least one magnet element from the laminated core.

[0030] The at least one magnetic element is inserted together with the at least one insulating element into the at least one recess after the at least one magnetic element is provided with the at least one insulating element and is thus physically connected.

[0031] In the at least one recess, the at least one insulating element is located between the inner wall of the recess and the magnetic element located in the recess and thus electrically insulates the at least one magnetic element from the magnetic carrier.

[0032] The insulating element is preferably designed in a layered or sheathed manner and surrounds the at least one magnetic element around its periphery, preferably completely. In particular, the insulating element has a layer thickness of more than 1 millimeter, preferably more than 2 millimeters, especially more than 5 millimeters or more than 10 millimeters.

[0033] Preferably, the at least one insulating element and the at least one holding element or the at least two holding elements are formed in one piece.

[0034] In particular, the insulating element and the holding element(s) are formed from one and the same elastic and dielectric material, such as one and the same dielectric elastomer, in one and the same extrusion, injection molding, fluidized bed sintering or dipping process on the circumference of the at least one magnetic element.

[0035] According to yet another aspect of the invention, an electrical machine, in particular a permanent-magnet synchronous machine or a DC machine, is provided. The electrical machine comprises a stator and a rotor, wherein the stator and / or the rotor comprise a previously described magnet carrier.

[0036] Advantageous embodiments of the method described above are also to be regarded as advantageous embodiments of the magnetic carrier or the electrical machine, insofar as they are otherwise transferable to the above-mentioned magnetic carrier or the electrical machine. Similarly, advantageous embodiments of the magnetic carrier described above are also to be regarded as advantageous embodiments of the method or the electrical machine, insofar as they are otherwise transferable to the above-described method or the electrical machine.

[0037] In the following, exemplary embodiments of the invention are explained in more detail with reference to the accompanying drawings. In the drawings: Fig. 1A, Fig. 1B shows, in respective schematic cross-sectional representations, a rotor of a permanent magnet synchronous machine according to an embodiment of the invention; Fig. 2 in a schematic cross-sectional view a recess of a Fig. 1A, Fig. 1B shown rotor including an inserted magnetic element.

[0038] Fig. 1A shows a rotor RT of a permanent magnet synchronous machine according to an embodiment in a schematic cross-sectional view transverse to its rotor axis RA, which runs perpendicular to the plane of the figure.

[0039] The rotor RT comprises a magnet carrier MT, which in turn comprises a laminated core BP with a number of recesses AN. The recesses AN extend in the direction of the rotor axis RA from one axial end to another opposite axial end of the laminated core BP and thus form individual through-holes in the laminated core BP. The recesses AN are arranged in a circular distribution in the radial edge region RB of the laminated core BP, viewed in the direction of the rotor axis RA. In each of the recesses AN, a magnetic element made of an iron-cobalt-nickel alloy and several holding elements made of a dielectric elastomer are arranged, which are described below with reference to Fig. 2 are described in detail.

[0040] Fig. 1B shows a rotor RT of a permanent magnet synchronous machine according to a further embodiment, also in a schematic cross-sectional view transverse to its rotor axis RA, which runs perpendicular to the plane of the figure.

[0041] In this embodiment, the recesses AN in the radial edge region RB of the laminated core BP are distributed and placed at an angle to one another in such a way that, viewed in the direction of the rotor axis RA, they simulate the shape of the corners of a multi-pointed star, such as a Star of David or an asterisk. Also arranged in the recesses AN are a magnetic element made of an iron-cobalt-nickel alloy and several holding elements made of a dielectric elastomer, which are also described below with reference to Fig. 2 are described in detail.

[0042] An embodiment of the recesses, the magnetic elements and the holding elements of a Fig. 1A and Fig. The rotor RT shown in Figure 1B is shown as an example in Fig. 2 shown in detail.

[0043] In this embodiment, the recess AN has a substantially rectangular cross-sectional area. A magnetic element ME along with a protective arrangement SA is arranged in the recess AN.

[0044] The magnetic element ME is designed to extend in the direction of the rotor axis RA and has a substantially rectangular cross-sectional area.

[0045] The protective arrangement SA is made of a dielectric elastomer and comprises an insulating element IE, which completely encloses the magnetic element ME in its circumference like a jacket.

[0046] The protective arrangement SA further comprises five retaining elements HE, which are distributed on the outside of the insulating element IE and protrude from the surface of the insulating element IE, extending in a rib-like manner in the direction of the rotor axis RA. The magnetic element ME, together with the protective arrangement SA, is secured in the recess AN via the five retaining elements HE. The five retaining elements HE press against the inner wall IW of the recess AN, thus softly and resiliently holding the magnetic element ME in the center of the recess AN. The jacket-like insulating element IE electrically insulates the magnetic element ME from the laminated core BP.

[0047] The following describes a method by which the magnetic elements ME are inserted into the recesses AN and held in the respective recesses AN by the holding elements HE.

[0048] First, a laminated core BP with a number of recesses AN and a corresponding number of magnetizable elements made of the iron-cobalt-nickel alloy are provided.

[0049] A protective assembly SA, each with a sheath-like insulating element IE and five elastic retaining elements HE, is attached to the periphery of the respective magnetizable elements. For this purpose, the magnetizable elements are overmolded with a dielectric elastomer, which, after curing, forms the respective protective assembly SA or the sheath-like insulating element IE and the five elastic retaining elements HE.

[0050] The magnetizable elements, along with their respective protective devices (SA), are then inserted into the corresponding recesses (AN) in the respective insertion direction, which runs parallel to the rotor axis (RA) and the longitudinal direction of the magnetizable element. Due to the elastic deformation, the retaining elements (HE) adapt to the contour of the inner wall (IW) of the respective recesses (AN), allowing the magnetizable elements to be inserted into the respective recesses (AN) without exerting a great deal of pressing force. Furthermore, the deformation of the retaining elements (HE) creates positive and frictional connections between the retaining elements (HE) and the corresponding recesses (AN), which hold the magnetizable elements firmly in the respective recesses (AN).

[0051] After the magnetizable elements together with the protective arrangements SA have been introduced into the respective recesses AN and fastened, they are magnetized (in a manner known to the person skilled in the art) to form magnetic elements ME by repeated exposure to a magnetic field.

Claims

[1] Method for producing a magnetic carrier (MT) for an electrical machine, comprising the following steps: - Providing a laminated core (BP) with at least one recess (AN) for receiving at least one magnetic element (ME); - Providing the at least one magnetic element (ME); - Providing the at least one magnetic element (ME) on its circumference with at least one elastic holding element (HE); - inserting the at least one magnetic element (ME) into the at least one recess (AN) after the at least one magnetic element (ME) has been provided with the at least one elastic holding element (HE); - wherein the at least one magnetic element (ME) is provided with at least two holding elements (HE), wherein the at least two holding elements (HE) are arranged spatially separated from one another on the circumference of the at least one magnetic element (ME) and hold the at least one magnetic element (ME) in the at least one recess (AN); - wherein at least one insulating element (IE) is arranged on the circumference of the at least one magnetic element (ME) before inserting the magnetic element (ME) into the recess, so that the insulating element (IE) is physically firmly connected to the magnetic element (ME), wherein the at least one insulating element (IE) electrically insulates the at least one magnetic element (ME) from the laminated core (BP), and the at least one insulating element (IE) and the at least one holding element (HE) are formed integrally with one another, wherein by elastic deformation of the holding element (HE) it is adapted to a contour of an inner wall (IW) of the recess (AN). [2] The method of claim 1, further comprising the step of: - Magnetizing the at least one magnetic element (ME) after the at least one magnetic element (ME) together with the at least one holding element (HE) has been introduced into the at least one recess (AN). [3] Method according to one of the preceding claims, wherein the at least one magnetic element (ME) together with the at least one insulating element (IE) is introduced into the at least one recess (AN) after the at least one magnetic element (ME) has been provided with the at least one insulating element (IE). [4] Magnetic carrier (MT) for an electrical machine, comprising: - a laminated core (BP) with at least one recess (AN) for receiving at least one magnetic element (ME); - at least one magnetic element (ME) arranged in the at least one recess (AN), - at least one elastic holding element (HE) which is arranged on the circumference of the at least one magnetic element (ME) and which holds the at least one magnetic element (ME) in the at least one recess (AN); - wherein the at least one magnetic element (ME) together with the at least one elastic holding element (HE) is inserted into the at least one recess (AN) after the at least one magnetic element (ME) is provided with the at least one elastic holding element (HE); - the magnet carrier (MT) further comprises at least two holding elements (HE) which are arranged spatially separated from one another on the circumference of the at least one magnet element (ME) and hold the at least one magnet element (ME) in the at least one recess (AN); - wherein at least one insulating element (IE) in the at least one recess (AN), which is arranged on the circumference of the at least one magnetic element (ME) and electrically insulates the at least one magnetic element (ME) from the laminated core (BP), wherein the insulating element is physically firmly connected to the magnetic element (ME), and the at least one insulating element (IE) and the at least one holding element (HE) are formed integrally with one another, and by elastic deformation of the holding elements (HE), these adapt to a contour of an inner wall (IW) of the respective recesses (AN). [5] Magnetic carrier (MT) according to claim 4, wherein the at least one magnetic element (ME) is magnetized after insertion into the at least one recess (AN). [6] Electrical machine comprising a rotor (RT) and a stator, wherein the rotor (RT) and / or the stator comprise a magnet carrier (MT) according to one of claims 4 to 5.

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