Method for mounting a permanent magnet on a magnet carrier and electric machine

Abstract

The invention relates to a method (40) for mounting a permanent magnet (30), which has a reservoir (36) on its outer side, on a magnet carrier (26) which has a pocket (28). The reservoir (36) is filled with an adhesive (38), and the permanent magnet (30) is inserted into the pocket (28). The adhesive (38) is subsequently cured. The invention further relates to an electric machine (4).

Description

[0001] FDST Patent Attorneys, Nuremberg Page 1

[0002] P240599P-RF / SES / MS

[0003] Description

[0004] Method for mounting a permanent magnet on a magnet carrier and electrical machine

[0005] The invention relates to a method for mounting a permanent magnet on a magnet carrier and an electric machine.

[0006] Industrial plants typically feature actuators driven by electric motors. For example, in plastics processing and manufacturing, augers or press rams are usually driven by electric motors. Here, for instance, a ram or screw of a plastic injection molding machine is moved by the electric motor. It is also possible to operate a conveyor belt, a lifting device, and / or tools using such an electric motor. Another application of electric motors can be found in the maritime sector, where the electric motor is, for example, mounted in a gondola on the hull of a ship.

[0007] Electric motors are typically brushless and feature a stator with multiple electromagnets, usually connected to several electrical phases, for example, 3 or 6. These phases are generally connected in a delta or star configuration and are energized by an inverter. The rotor of the respective electric motor, on the other hand, is permanently excited and comprises a number of permanent magnets attached to a rotor body. It is possible to attach the permanent magnets to the outside of the rotor body. However, this requires a relatively specialized shaping of the permanent magnets, which increases manufacturing costs. Furthermore, it is possible that...

[0008] (w:\winpat5\document\amt\4101878 docx) Last saved: October 15, 2025 FDST Patent Attorneys, Nuremberg Page 2 Due to the high centrifugal forces, the permanent magnets can detach from the rotor body and destroy the electric motor due to the comparatively rapid rotation of the rotor.

[0009] Therefore, the rotor body typically has several pockets, into each of which one of the permanent magnets is inserted parallel to the axis of rotation, i.e., longitudinally. Usually, an interference fit is achieved between the permanent magnet and the pocket, resulting in a relatively stable connection. However, at elevated operating temperatures, the frictional connection between the rotor body and the permanent magnets can be compromised due to differing thermal expansion rates. In this case, the permanent magnets could detach from the rotor body. To prevent this, the permanent magnets are usually bonded to the rotor body after mounting, for which an adhesive is applied to their end faces. Due to the interference fit, only a relatively small amount of adhesive is applied between them, resulting in a comparatively weak bond.This also requires an additional work step, which is why the production time is extended.

[0010] The invention is based on the objective of providing a particularly suitable method for mounting a permanent magnet on a magnet carrier and a particularly suitable electrical machine, advantageously increasing robustness and expediently facilitating manufacturing and / or reducing manufacturing time.

[0011] With regard to the method, this problem is solved according to the invention by the features of claim 1, and with regard to the electrical machine by the features of claim 3. Advantageous further developments and embodiments are the subject of the respective dependent claims.

[0012] This process involves mounting a permanent magnet onto a magnet carrier. The magnet carrier can be, for example, a single piece made of a sintered material. Alternatively, the magnet carrier can be...

[0013] (w:\winpat5\document\amt\4101878 docx) Last saved: October 15, 2025 FDST Patent Attorneys, Nuremberg Page 3, for example, a laminated core. The magnet carrier has a pocket into which the permanent magnet is inserted and held after completion of the process. The pocket is suitably designed with a smooth inner surface, which facilitates manufacturing. Preferably, the magnet carrier is made of a ferromagnetic material, so that the magnetic fields provided by the permanent magnet are suitably shaped by means of it. The permanent magnet is, for example, made of ferrite or rare earth elements. The process is suitably used in the manufacture of an electric machine, such as an electric motor or a generator. In this case, the magnet carrier is, for example, a component of a stator or, preferably, a component of a rotor.In particular, the magnet carrier is provided by means of a laminated core, and preferably a rotor body of the rotor, which is expediently attached to a shaft of the electric machine in the assembly state.

[0014] In this process, a reservoir within the permanent magnet is filled with an adhesive. The permanent magnet has the reservoir on its external surface. For example, the reservoir is first inserted into the outside of the permanent magnet, or the permanent magnet is expediently manufactured or provided with the reservoir already present. The reservoir is located on the outside of the permanent magnet and is, for example, at least partially formed by the surface of the permanent magnet. In particular, it is a depression, and the surface area of ​​the permanent magnet is suitably enlarged, at least locally, due to the reservoir. In summary, the surface of the permanent magnet is at least locally recessed due to the reservoir. The reservoir expediently has edges that are offset outwards relative to other components of the reservoir.For example, the edges and other components of the side of the permanent magnet containing the reservoir are located in a common plane, whereas the reservoir is offset with respect to this plane and therefore does not lie in it.

[0015] (w:\winpat5\document\amt\4101878 docx) Last saved: October 15, 2025 FDST Patent Attorneys, Nuremberg Page 4

[0016] The adhesive is, for example, liquid or paste-like when it is poured into the reservoir. It is advantageous to completely fill the reservoir with the adhesive. This ensures that the adhesive is flush with the rest of the surface of the side of the permanent magnet that contains the reservoir.

[0017] The permanent magnet is then inserted into the pocket. Advantageously, the permanent magnet is guided along the inside of the pocket and, after insertion, preferably rests against the inside of the pocket. Suitablely, the permanent magnet is completely surrounded by the inside of the pocket and preferably rests completely against it. The reservoir advantageously remains free of the magnet carrier, and the magnet carrier thus does not, in particular, immerse itself in the reservoir. Consequently, due to the reservoir, the permanent magnet is locally spaced from the magnet carrier, and the adhesive is located in this area.

[0018] After the permanent magnet has been inserted into the pocket and, in particular, positioned appropriately, the adhesive is cured. This is achieved, for example, by heating the magnet carrier and / or the permanent magnet itself, causing the adhesive to dry. Alternatively, the curing process can be initiated by waiting for a certain period of time. Another alternative is to add an additional component, especially if the adhesive is a multi-component adhesive. Alternatively, the adhesive can be exposed to a specific type of radiation, such as infrared or ultraviolet radiation, to cure. As the adhesive cures, it cross-links, effectively bonding the permanent magnet to the pocket. Ideally, the adhesive creates at least a localized, metallurgical bond between the permanent magnet and the magnet carrier.

[0019] Due to the process, the permanent magnet is thus connected to the adhesive over a comparatively large area, namely via the surface of the reservoir. The adhesive is also in contact with the magnet carrier over a comparatively large area, resulting in a comparatively large bond between the permanent magnet and the magnet carrier. Because of this

[0020] (w:\winpat5\document\amt\4101878 docx) Last saved: October 15, 2025 FDST Patent Attorneys, Nuremberg Page 5 Due to the large adhesive surface, forces acting between the permanent magnet and the magnet carrier can be absorbed relatively well by the adhesive bond, thus increasing robustness. Thanks to the reservoir, shearing or stripping of the adhesive during insertion and movement of the permanent magnet in the pocket is essentially prevented. This ensures that, after the permanent magnet is inserted into the pocket, the reservoir remains full of adhesive for bonding. This reduces rejects during production. No special precautions are necessary when inserting the permanent magnet into the pocket, simplifying the insertion process and therefore also the manufacturing process.The gluing process also takes place in one step along with the insertion of the permanent magnets into the pocket, which reduces manufacturing time.

[0021] An acrylate, particularly a multi-component acrylate system, is advantageously used as the adhesive. Such an adhesive is available, in particular, under the trade name "precote" from omniTECHNIK Mikroverkapselungs GmbH. For example, only the reservoir is coated with the adhesive. If the adhesive has a comparatively high initial tack, the force required to insert the permanent magnet into the pocket is reduced due to the arrangement being limited to the reservoir. Alternatively, other components of the permanent magnet, in particular parts of the surface of the permanent magnet that lie against the inside of the pocket during assembly, are also coated with the adhesive. This further improves the adhesive effect. For example, the magnet carrier has only a single pocket. However, it is particularly preferred that the magnet carrier comprises several such pockets, each containing a permanent magnet.For example, the permanent magnets are inserted into the respective pockets one after the other or simultaneously.

[0022] For example, the permanent magnet is simply inserted loosely into the bag, and it is conveniently attached there only by means of the adhesive. Therefore, there is a suitable barrier between the permanent magnet and the bag.

[0023] (w:\winpat5\document\amt\4101878 docx) Last saved: October 15, 2025 FDST Patent Attorneys, Nuremberg Page 6 A clearance fit is achieved, which facilitates insertion. However, the permanent magnet is preferably pressed into the pocket. Consequently, an interference fit is created between the permanent magnet and the magnet carrier, resulting in a frictional connection. As a result, the permanent magnet is also held to the magnet carrier by this frictional connection, thus reducing the forces that the adhesive bond must additionally absorb. This reduces the demands placed on the adhesive. The reservoir ensures that when the permanent magnet is pressed into the pocket, the adhesive remains on the permanent magnet and is not sheared or wiped off.

[0024] The electric machine is, for example, equipped with brushes. However, it is particularly preferred that the electric machine be brushless. For example, the electric machine is a generator. However, it is particularly preferred that the electric machine is an electric motor, especially a brushless electric motor. The electric machine is, in particular, a synchronous machine, such as a synchronous motor. Preferably, during operation, the electric machine is electrically connected to and operated by means of a converter, or includes the converter. The electric machine has, for example, a power output between 0.1 kW and 30 kW, between 0.2 kW and 25 kW, or between 0.3 kW and 19 kW, and in particular equal to 10 kW, with, for example, a deviation of 2 kW, 1 kW, 0.5 kW, or 0 kW in each case.

[0025] Suitablely, the electric machine has a speed, for example a rated speed or maximum speed, between 10 rpm and 800 rpm, between 30 rpm and 600 rpm, between 50 rpm and 500 rpm, or between 100 rpm and 400 rpm, with a deviation of 100 rpm, 50 rpm, 20 rpm, or 0 rpm being particularly desirable. Alternatively, the electric machine expediently has a speed, for example a rated speed or maximum speed, between 10 rpm and 5,000 rpm, between 100 rpm and 3,000 rpm, between 1,000 rpm and 3,000 rpm, or between 2,000 rpm. and 3,000 rpm, in particular where a deviation of 500 rpm, 200 rpm, 100 rpm or 0 rpm is present.

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[0027] Particularly preferably, the electric machine has a torque, for example a maximum and / or rated torque between 300 Nm and 200,000 Nm, between 500 Nm and 175,000 Nm, between 500 Nm and 150,000 Nm, between 500 Nm and 100,000 Nm or between 500 Nm and 80,000 Nm, wherein in particular there is a deviation of 100 Nm, 50 Nm, 10 Nm or 0 Nm.

[0028] Preferably, the electric machine serves to drive an actuator in an industrial plant, such as a conveyor belt, a robot, or a component for processing or manufacturing a component, such as a press or a conveyor crawler. For example, the electric machine is a component of a servo press. In other words, the electric machine is used to drive a press. Alternatively, the electric machine is preferably used in plastics processing and / or plastics manufacturing. For example, an extruder or another component of a plastics injection molding machine, such as a die, is driven by the electric machine. For example, the electric machine is a component of a filling system, an injection molding machine, or a textile machine.

[0029] Alternatively, the electric machine is a component of a ship's propulsion system, specifically designed and configured to be mounted inside a gondola on the hull of a ship. In another alternative, the electric machine is a component of a bicycle, such as a pedelec, and serves to propel the bicycle. For example, the electric machine is a component of a commercial vehicle, and in particular, of the vehicle's drive system. Most preferably, the electric machine is a component of the commercial vehicle's main drive system and thus serves to propel the vehicle. For this purpose, in its assembled state, the electric machine is coupled to a wheel of the commercial vehicle, for example, directly or indirectly via a transmission. In other words, the electric machine forms a main machine of the commercial vehicle or at least one of its components.

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[0031] Main engine of the commercial / motor vehicle, provided the commercial / motor vehicle has several main engines.

[0032] The electric machine comprises a permanent magnet with an external reservoir and a magnet holder with a pocket into which the permanent magnet is inserted. An adhesive is contained within the reservoir, bonding the permanent magnet and the magnet holder together.

[0033] Due to the reservoir, a relatively large amount of adhesive is available, ensuring that the permanent magnet is securely held to the magnet carrier, even if, for example, manufacturing tolerances or similar factors result in relatively weak forces holding the permanent magnet to the magnet carrier, or if other fastening methods are limited in their functionality. This increases robustness.

[0034] The adhesive is, for example, liquid, pasty, or preferably cured. In other words, the adhesive is primarily a solid. This prevents unwanted leakage of the adhesive from the reservoir and ensures that the permanent magnet remains bonded to the magnet holder even after a relatively long operating period. For example, during assembly, the permanent magnet is first inserted into the pocket, and then the reservoir is filled with the adhesive. However, it is particularly preferred that the reservoir is filled with the adhesive first, and only then is the permanent magnet inserted into the pocket. This simplifies the manufacturing process.

[0035] Preferably, the electric machine comprises a stator and a rotor. The stator is expediently designed as a hollow cylinder and extends along a machine axis. In other words, the stator is arranged around the machine axis. An axial direction, parallel to the machine axis, is defined by means of this axis. Radial and tangential directions are also defined by means of the machine axis. Preferably, the stator is designed to be rotationally symmetrical with respect to the machine axis.

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[0037] In its assembled state, the stator advantageously surrounds a rotor of the electric machine, which is rotatably mounted about the machine axis, thus constituting the axis of rotation of the electric machine. In particular, the electric machine is thus designed as an internal rotor. The rotor is advantageously designed to be rotationally symmetrical with respect to the machine axis. Specifically, the electric machine has a shaft, which is made, for example, of steel. The shaft is advantageously arranged concentrically to the machine axis, and the rotor is advantageously mounted on the shaft. For this purpose, the rotor advantageously has a suitable recess, so that the rotor is essentially hollow-cylindrical. Preferably, the rotor is connected to the shaft in a rotationally fixed manner, for example, by means of a tongue-and-groove connection.

[0038] For example, the magnet carrier is independent of the stator and the rotor. In particular, the magnet carrier forms part of the stator or, more preferably, of the rotor. Advantageously, a rotor body of the rotor is formed by means of the magnet carrier. Preferably, the magnet carrier comprises several laminations and is, for example, designed as a laminated core. The pocket advantageously runs parallel to the axial direction. For example, the pocket is open at the edges, particularly in the radial direction. More preferably, however, the pocket is closed circumferentially and has an opening only at the ends in the axial direction through which the permanent magnet can be inserted.

[0039] Preferably, the magnet carrier comprises several corresponding pockets, each containing an associated permanent magnet. The permanent magnets are suitably identical in construction. Preferably, they are arranged rotated relative to each other, resulting in a comparatively effective form of the magnetic field thus generated.

[0040] The reservoir, for example, comprises several separate depressions or craters, so that the surface of the permanent magnet in the reservoir area is corrugated or ribbed. Alternatively, the reservoir can be constructed using

[0041] (w:\winpat5\document\amt\4101878 docx) Last saved: October 15, 2025 FDST Patent Attorneys, Nuremberg Page 10 Several indentations are formed, so that the surface of the permanent magnet in the reservoir area is golf ball-like. This creates distinct areas and improves the adhesion of the adhesive to the permanent magnet. Preferably, however, the reservoir includes a groove that is machined into the surface of the permanent magnet. In this case, for example, the permanent magnet is pre-formed with the groove already in place, or the groove is preferably machined into the permanent magnet only after its initial production. Thus, it is possible to use an existing permanent magnet as a kind of semi-finished product and machine the groove into it to provide the reservoir. Consequently, no special mold is required for manufacturing the permanent magnet, which reduces production costs.This reduces the time required to insert the reservoir. Furthermore, it allows the groove depth to be adjusted to the specific application, while always using the same semi-finished product: the permanent magnet, which does not yet have a groove. This enables adaptation to different applications without the need for special pre-forming of the permanent magnet, thus reducing manufacturing costs.

[0042] Specifically, the groove is located on an otherwise flat side of the permanent magnet. To provide the reservoir, the groove is cut into this flat surface. In other words, if the groove were not present, the side / surface of the permanent magnet would be flat. Because of the groove, the side is not flat, and the surface of the permanent magnet is recessed inwards in the area of ​​the reservoir.

[0043] For example, the cross-section of the permanent magnet, particularly with the exception of irregularities caused by the reservoir, is semicircular or triangular. However, a rectangular cross-section is particularly preferred, particularly with the exception of irregularities caused by the reservoir. Consequently, the permanent magnet is cuboid-shaped, with, for example, any edges being flattened. This simplifies storage, and existing permanent magnets can be used, for example. Alternatively, or particularly preferably in combination with this,

[0044] (w:\winpat5\document\amt\4101878 docx) Last saved: October 15, 2025 FDST Patent Attorneys, Nuremberg Page 11 The pocket has a rectangular cross-section. This simplifies manufacturing and, in particular, makes it possible to use an existing magnet carrier, such as a rotor or stator.

[0045] For example, the groove has a rectangular cross-section. However, a semicircular cross-section is particularly preferred. This simplifies the application of the adhesive, and the absence of relatively sharp edges ensures that the reservoir is completely filled with the adhesive, even if it is relatively viscous. This simplifies manufacturing and increases the adhesive strength. Consequently, the bonding of the permanent magnet to the magnet carrier is improved.

[0046] For example, the groove runs perpendicular to the contour of the pocket. The groove can, for instance, be circumferential. However, it is particularly preferred that the groove runs parallel to the pocket and is thus, in particular, parallel to the machine axis and / or axial direction. As a result of the groove, the path of the magnetic field provided by the permanent magnet is not excessively altered, and therefore the operation of the electric machine is not impaired. Consequently, a complete redesign of an existing electric machine is essentially unnecessary, and the modification has essentially no negative effects on the electric machine. The modification, for example, simply requires cutting a corresponding groove into the existing permanent magnet and applying the adhesive to it.This also makes it possible to visually check whether the adhesive has been displaced from the reservoir due to or after the insertion of the permanent magnet into the pocket. Furthermore, refilling the adhesive is possible. Additionally, the curing process is simplified if further treatment is required, such as adding another component and / or exposing the adhesive to a specific type of radiation.

[0047] A cuboid-shaped permanent magnet is particularly preferred, which allows for the use of an existing semi-finished product. The groove is conveniently integrated into one of the long sides. This ensures that

[0048] (w:\winpat5\document\amt\4101878 docx) Last saved: October 15, 2025 FDST Patent Attorneys, Nuremberg Page 12 the adhesive arranged in the reservoir comes into contact with the inside of the bag over a comparatively large length / area, so that an adhesive force is increased, i.e. the forces provided by means of the adhesive and acting between the permanent magnet and the magnet carrier.

[0049] For example, the reservoir comprises only a single groove. However, it is particularly preferred that the reservoir has an additional groove, which is suitably identical in design to the first groove. Advantageously, the two grooves run parallel to each other. For example, the two grooves are located on the same longitudinal side. However, it is particularly preferred that the additional groove is located on the opposite longitudinal side. Thus, the permanent magnet is held to the magnet carrier on two opposite longitudinal sides by means of the adhesive, which increases stability.

[0050] Particularly preferably, the permanent magnet is symmetrically designed, with the two grooves preferably lying on a common axis / plane of symmetry. Thus, there is no preferred orientation of the permanent magnet, and the permanent magnet is always correctly oriented in the pocket. Consequently, assembly is simplified. Furthermore, the magnetic field lines provided by the permanent magnet are not asymmetrically deformed.

[0051] For example, several such grooves are present. However, it is particularly preferred that only the first groove and the second groove are present, which prevents excessive structural weakening of the permanent magnet. Manufacturing is also simplified.

[0052] For example, a clearance fit is formed between the permanent magnets and the pocket. This facilitates the insertion of the permanent magnet into the pocket. However, a frictional connection is particularly preferred between the permanent magnet and the pocket, especially between the inside of the pocket and the outside of the permanent magnet, i.e., the surface of the permanent magnet, with the exception of the surface in the reservoir area. There, due to the reservoir, the surface of the permanent magnet is...

[0053] (w:\winpat5\document\amt\4101878 docx) Last saved: October 15, 2025 FDST Patent Attorneys, Nuremberg Page 13 The permanent magnet is held in the pocket by means of the adhesive. Due to the frictional connection, the permanent magnet is thus held in the pocket, and the adhesive preferably serves only as an additional safeguard, for example, if the frictional connection is partially lost due to differing thermal expansion. Consequently, the requirements for the adhesive are reduced. A positive connection is also suitably formed between the permanent magnet and the pocket, particularly with the exception of the reservoir. This increases stability.

[0054] For example, to achieve a force-fit connection, the magnet carrier is shrunk onto the permanent magnet. Here, the adhesive acts as a lubricant, reducing the force required to insert the permanent magnet. Ideally, the permanent magnet is completely surrounded by the adhesive, which facilitates insertion. However, if the adhesive already has a relatively high initial tack, it is preferable to have the adhesive only in the reservoir, which also simplifies insertion.

[0055] However, the most preferred method is to achieve the force-fit connection by pressing the permanent magnet into the pocket. This is done by applying a sufficiently large force to press the permanent magnet into the pocket. As a result, the inside of the pocket, for example if there are manufacturing tolerances, is elastically and / or plastically deformed, thus achieving a comparatively secure connection between the permanent magnet and the magnet carrier.

[0056] The invention further relates to an industrial plant with such an electric machine, which is expediently designed as an electric motor. The industrial plant expediently includes a converter by means of which the electric motor is energized and electrically connected.

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[0058] The further training and advantages gained in connection with the process can also be transferred analogously to the electrical machine / the industrial plant and to each other, and vice versa.

[0059] An embodiment of the invention is explained in more detail below with reference to a drawing. The drawing shows:

[0060] Fig. 1 schematically shows an industrial plant with an electric machine shown in a sectional view along an axis of rotation, comprising a rotor acting as a magnet carrier,

[0061] Fig. 2 schematically shows in a sectional view perpendicular to the axis of rotation the rotor, which has several pockets, each containing a permanent magnet,

[0062] Fig. 3 shows one of the permanent magnets in perspective, and

[0063] Fig. 4 shows a method for mounting the permanent magnets on the magnet carrier.

[0064] Corresponding parts are marked with the same reference symbols in all figures.

[0065] Figure 1 shows a simplified schematic representation of an industrial plant 2 comprising an electric machine 4. The electric machine 4 is designed as a brushless electric motor, and an actuator 6, such as a conveyor belt, is driven by means of this motor. The electric machine 4 is powered by a converter 8, which is electrically connected to the electric machine 4.

[0066] The electric machine 4, shown in a sectional view along a machine axis 10, has a shaft 12 made of steel, arranged on and concentric to the machine axis 10. The actuator 6 is mechanically connected to this shaft. A rotor 14 is fixed to the circumference of the shaft 12 in a rotationally fixed manner.

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[0068] The rotor 14 is surrounded by a hollow cylindrical stator 16, which is arranged concentrically to the machine axis 10. The stator 16 is attached to a hollow cylindrical housing 18 at its circumferential side, the end faces of which are each closed by means of a bearing shield 20. The bearing shields 20 are arranged perpendicular to the machine axis 10, and each bearing holds a bearing (not shown) by means of which the shaft 12, and therefore also the rotor 14, is rotatably mounted about the axis of rotation 10.

[0069] The rotor 14, shown in a sectional view perpendicular to the machine axis 10 in Figure 2, has a rotor body 22 formed by a laminated core. The individual laminations of the core are stacked one above the other in an axial direction parallel to the machine axis 10. The rotor body 22 has a smooth surface on its circumferential side and a round, continuous opening 24 on its inner side, which lies on the machine axis 10 and within which the shaft 12 is located in the assembled state.

[0070] The rotor body 22 forms a magnet carrier 26 and has several pockets 28 that have a rectangular cross-section perpendicular to the machine axis 10. The pockets 28 are identical in construction to each other, but rotated with respect to the machine axis 10. In the example shown, there are a total of four such pockets 28, which are rotated and offset from each other by 90° with respect to the machine axis 10. The pockets 28 extend through the entire rotor body 22.

[0071] Within each pocket 28, a permanent magnet 30 is inserted, one of which is shown in perspective in Figure 3. The permanent magnet 30 is made of sintered ferrite and is essentially cuboid in shape. Unlike a pure cuboid, the edges are flattened, and a groove 34 is formed in each of the opposite longitudinal sides 32, together forming a reservoir 36. Thus, the permanent magnet 30 surrounds the reservoir 36 on the outside.

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[0073] The two grooves 34 are identical and have a semicircular cross-section. The surface area of ​​the longitudinal sides 32 is increased by the two grooves 34. The grooves 34 are essentially located centrally in each longitudinal side 32 and run parallel to the pocket, i.e., parallel to the machine axis 10 and thus parallel to the axial direction. The grooves 34 are arranged such that the cross-section of the permanent magnet 30 is axially symmetrical, namely about an axis parallel to the longitudinal sides 32 and about an axis perpendicular to the longitudinal sides 32. In summary, each permanent magnet 30 is cuboid in shape, with one of the grooves 34 located in one of the longitudinal sides 32. The reservoir 36 also has the additional groove 34 located in the opposite longitudinal sides 32.The grooves 34 of the reservoir 36 are incorporated into the surfaces of the permanent magnet 30 and each has a semicircular cross-section.

[0074] The reservoir 36, i.e., the two grooves 34, are each filled with an adhesive 38, which is thus flush with the respective longitudinal side 32. The adhesive 38 therefore lies flat against the inside of the respective pocket 28 into which the respective permanent magnet 30 is inserted. A force-fit is thus formed between each permanent magnet 30 and the respective pocket 28. This holds the respective permanent magnet 30 in its assigned pocket 28. Furthermore, due to the adhesive 38, each permanent magnet 30 is bonded to the inside of the pocket 28 on the opposite longitudinal sides 32 and thus bonded to the magnet carrier 26. The adhesive 38 used is a multi-component acrylate system, namely "precote" from omni-TECHNIK Mikroverkapselungs GmbH.

[0075] Figure 4 shows a method 40 for mounting one of the permanent magnets 30 to the magnet carrier 26. In particular, the method 40 is carried out for each of the permanent magnets 30, preferably in parallel. In a first step 42, the reservoir 36 is filled with the adhesive 38. For this purpose, the permanent magnet 30 is first provided. For example, it already has the reservoir 36

[0076] (w:\winpat5\document\amt\4101878 docx) Last saved: October 15, 2025 FDST Patent Attorneys, Nuremberg Page 17. Alternatively, the longitudinal sides 32 are still smooth, and the permanent magnet 30 is obtained in this form from a supplier. To provide the reservoir 36, the respective groove 34 is then machined into the opposite longitudinal sides 32, preferably by milling. Thus, a special pre-forming of the permanent magnet 30 is not required, and it is not necessary, for example, to modify a mold used for sintering the permanent magnet 30.

[0077] Precote is used as the adhesive 38, which is filled into the grooves 34. The acrylate system is microencapsulated. Therefore, until activation / breakage of the encapsulation, it exhibits only a low adhesive and / or holding force, which facilitates handling of the permanent magnet 30. This also allows for storage. In particular, it is possible to carry out the first step 42 at a comparatively long interval before the subsequent steps of the process 40.

[0078] After the first step 42, in a second step 44, the permanent magnet 30 is inserted into its corresponding pocket 28. During the manufacture of the rotor 14, all permanent magnets 30 are inserted, or pressed in, into their respective pockets 28 essentially simultaneously. The permanent magnet 30 has an oversize relative to the respective pocket 28, which is why this is only possible with a comparatively high force. During insertion, due to the oversize, the permanent magnet 30 and / or the magnet body 26 are at least partially elastically and / or plastically deformed. In summary, the permanent magnet 30 is pressed into its corresponding pocket 28. A comparatively large force is also exerted on the adhesive 38. As a result, the microencapsulations of the precote rupture, and the adhesive 38 is activated.

[0079] In a subsequent third step 46, the adhesive 38 is cured. For this, a certain period of time is allowed to set and / or the magnet carrier 26, i.e., the rotor body 22, is heated at least slightly. Thus,

[0080] (w:\winpat5\document\amt\4101878 docx) Last saved: October 15, 2025 FDST Patent Attorneys, Nuremberg Page 18 The permanent magnet 30 is held on the magnet carrier 26 by means of frictional contact, as well as by means of the adhesive 38. The adhesive 38 serves as a safeguard in case the frictional contact should be interrupted or reduced due to different thermal expansion during operation of the electric machine 4.

[0081] The invention is not limited to the embodiment described above. Rather, other variants of the invention can also be derived by a person skilled in the art without departing from the subject matter of the invention. In particular, all individual features described in connection with the embodiment can also be combined with one another in other ways without departing from the subject matter of the invention.

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[0083] Reference symbol list

[0084] 2 industrial plant

[0085] 4 electric machine

[0086] 6 Actuator

[0087] 8 inverters

[0088] 10 machine axis

[0089] 12th wave

[0090] 14 Rotor

[0091] 16 Stator

[0092] 18 cases

[0093] 20 Storage sign

[0094] 22 rotor bodies

[0095] 24-hour opening

[0096] 26 magnetic carriers

[0097] 28 bags

[0098] 30 permanent magnets

[0099] 32 Long side

[0100] 34 Nut

[0101] 36 Reservoir

[0102] 38 Adhesive

[0103] 40 procedures

[0104] 42 first step

[0105] 44 second step

[0106] 46 third step

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Claims

FDST Patent Attorneys, Nuremberg, page 20 Claims 1. Method (40) for mounting a permanent magnet (30) having an external reservoir (36) on a magnet carrier (26) having a pocket (28), wherein - the reservoir (36) is filled with an adhesive (38), - the permanent magnet (30) is inserted into the pocket (28), and - the adhesive (38) is cured.

2. Method (40) according to claim 1 , characterized in that the permanent magnet (30) is pressed into the pocket (28).

3. Electric machine (4) with a permanent magnet (30) having a reservoir (36) on the outside, and with a magnet carrier (26) having a pocket (28) into which the permanent magnet (30) is inserted, wherein an adhesive (38) is arranged in the reservoir (36) by means of which the permanent magnet (30) and the magnet carrier (26) are bonded together.

4. Electric machine (4) according to claim 3, characterized in that the reservoir (36) comprises a groove (34) which is provided in the surface of the permanent magnet (30).

5. Electric machine (4) according to claim 4, characterized in that the groove (34) has a semicircular cross-section.

6. Electric machine (4) according to claim 4 or 5, characterized in that the groove (34) runs parallel to the pocket (30). (w:\winpat5\document\amt\4101878 docx) Last saved: October 15, 2025 FDST Patent Attorneys, Nuremberg, page 21 7. Electric machine (4) according to one of claims 4 to 6, characterized in that the permanent magnet (30) is cuboid in shape, wherein the groove (34) is provided in one of the longitudinal sides (32).

8. Electric machine (4) according to claim 7, characterized in that the reservoir (36) comprises a further groove (34) which is provided in the opposite longitudinal side (32).

9. Electric machine (4) according to one of claims 3 to 8, characterized in that a force-fit connection is formed between the permanent magnet (30) and the pocket (28). (w:\winpat5\document\amt\4101878 docx) Last saved: October 15, 2025

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