DE102013211691A1 - Device and method for attaching at least one magnet in a magnetic receptacle of a rotor laminated core of a rotor of an electric machine - Google Patents

Abstract

The present invention relates to a device for attaching at least one magnet (14) in a magnet holder (22) of a rotor core (12, 46) of a rotor (10) of an electrical machine. The device has: a receptacle (44) which is designed to receive the laminated rotor core (46) at least temporarily, an adjustment unit (48) which is designed to perform a lifting movement in order to thereby create a distance between a tappet (38) and to change the laminated rotor core (46) arranged on the receptacle (44), an embossing unit (42) which is arranged on the ram (38) and has at least one punch (84), the embossing unit (42) being designed such that The stamp (84) in the area of the magnet holder (22) penetrates at least partially around the circumference of the rotor core (46) due to the lifting movement and the magnet (14) is jammed in the magnet holder (22) due to the material deformation in the edge area of the magnet holder (22), and a control unit (32) which is designed to process an adjustment path size and a pressure force variable and to adjust the adjustment unit (48) as a function of the adjustment path size and the pressure force size The adjustment path size represents that adjustment path by which the plunger (38) and the rotor lamination stack (46) move towards one another due to the stroke movement, and the compressive force value represents the force with which the punch (84) presses on the rotor lamination stack (46) . The invention also relates to a corresponding method and the embossing unit used.

Description

The invention relates to a device and a method for fastening at least one magnet in a magnetic receptacle of a rotor lamination stack of a rotor of an electrical machine. Furthermore, the invention relates to a stamping unit, which is designed for fastening at least one magnet in a magnetic receptacle of a rotor laminated core of a rotor of an electric machine.

Electric machines can be used in a variety of ways, including in the recent past as a prime mover in automotive. The vehicles can be designed as a hybrid vehicle or as an electric vehicle. In a hybrid vehicle in addition to the electric machine another unit is used for the drive, usually an internal combustion engine. Whereas an electric vehicle is driven exclusively by an electric machine. The electrical machines used are usually designed as internal rotor machines, in which a rotatably mounted rotor is enclosed by a stationary stator. The stator generates a rotating magnetic field, through which the rotor is taken. The rotor carries a rotor shaft, which is technically connected to a drive shaft of the vehicle.

For driving a vehicle synchronous machines, in particular hybrid synchronous machines can be used. The synchronous machine can be designed as a permanent magnet synchronous machine, are incorporated in the permanent magnets in the rotor. A hybrid synchronous machine is to be understood here as meaning a permanently excited synchronous machine which additionally has a pronounced reluctance effect due to a correspondingly selected rotor geometry, which is used to generate the torque acting on the rotor.

The rotor of an electric machine designed as a synchronous machine or as a hybrid synchronous machine is usually constructed from a plurality of rotor laminations, whereby a particularly favorable magnetic field behavior is achieved. Usually, a plurality of rotor laminations are structurally combined to form a rotor laminations. The rotor laminations have magnetic recordings in which the magnets or permanent magnets are used.

Due to the sometimes extreme operating conditions that prevail for a used in the automotive industry as a prime mover electric machine, in particular the electric machine is operated at very high speeds, the permanent magnets are fixed in the magnetic recordings. One approach heretofore common is to glue the permanent magnets in the magnetic recordings. However, this bonding of the permanent magnets is disadvantageous in many respects. Thus, a very great effort to operate, to ensure a reliable dosing and positioning of the adhesive in the magnetic recordings. Furthermore, the bonding of the permanent magnets is very time-consuming, since the curing of the adhesive is to wait before the rotor laminated core can be supplied to subsequent processing or processing steps. Although the amount of time can be reduced to some extent by accelerating the curing of the adhesive by heating the rotor core, this measure results in additional energy consumption and thus causes additional costs in the manufacture of a rotor and consequently in the manufacture of an electric machine. In addition, in the event that the permanent magnets are not already used in their magnetized state, but in an initially unmagnetized state in the magnetic recordings, also a great effort to operate to the first not magnetized magnets before and during the curing process of the adhesive in to position or hold the magnetic recordings. There are also problems with the recycling of bonded permanent magnets. Thus, on the one hand, a relatively large effort is required to release bonded permanent magnets from a rotor laminated core. On the other hand, it is very expensive to clean a detached permanent magnet of any existing adhesive residues. In addition, the handle of the adhesives used for bonding in terms of dosing, curing and also the storage of adhesives is complex. Furthermore, it is disadvantageous that the adhesives which are suitable for fixing the magnets, because of the requirements to be imposed on them, in particular with regard to their temperature resistance, are relatively expensive, resulting in high costs in the manufacture of a rotor and consequently in manufacture an electric machine leads.

It is therefore an object of the present invention to provide an apparatus and a method for attaching at least one magnet or permanent magnet in a magnetic receptacle of a rotor lamination of a rotor of an electric machine, with which the magnet can be fastened quickly, inexpensively and inexpensively, and with the or at the same time a high strength of the fixation of the magnet is ensured in the magnetic recording. Another object is to allow a simple, inexpensive and inexpensive recycling of magnet mounted in a rotor core.

This object is achieved by a device of the type mentioned, comprising the following means: a receptacle which is designed to is to accommodate the rotor core at least temporarily, an adjusting unit, which is adapted to perform a lifting movement, thereby changing a distance between a plunger and the rotor plate arranged on the receptacle, an embossing unit arranged on the plunger and having at least one plunger, wherein the embossing unit is designed in such a way that, due to the lifting movement, the stamp penetrates at least partially into the rotor laminated core and the magnet is jammed in the magnetic mount by the deformation of the material occurring in the edge region of the magnetic mount, and a control unit which is designed to process a Verstellweggröße and a compressive force size and to control the adjustment unit in dependence on the Verstellweggröße and the pressure force magnitude, wherein the Verstellweggröße represents those adjustment by which the plunger and the rotor core due to d he stroke movement move towards each other, and the pressure force size represents the force with which the punch presses on the rotor core.

• – Anordnen einer Prägeeinheit an einem Stößel, wobei die Prägeeinheit zumindest einen Stempel aufweist,
• – Anordnen des Rotorblechpakets an einer Aufnahme,
• – Einbringen des zumindest einen Magneten in die Magnetaufnahme,
• – Verarbeiten einer Verstellweggröße und einer Druckkraftgröße in einer Steuereinheit, wobei die Verstellweggröße denjenigen Verstellweg repräsentiert, um den sich der Stößel und das Rotorblechpaket aufgrund einer Hubbewegung aufeinander zubewegen, und wobei die Druckkraftgröße, diejenige Kraft repräsentiert, mit der der Stempel auf das Rotorblechpaket drückt,
• – Ansteuern einer Verstelleinheit in Abhängigkeit der Verstellweggröße und der Druckkraftgröße zum Durchführen der Hubbewegung, so dass der Stempel im Bereich der Magnetaufnahme aufgrund der Hubbewegung zumindest teilumfänglich in das Rotorblechpaket eindringt und der Magnet durch die dabei im Randbereich der Magnetaufnahme entstehende Materialverformung in der Magnetaufnahme verklemmt ist.

The object is further achieved by a method of the aforementioned type, in which the following steps take place:

• Arranging an embossing unit on a plunger, wherein the embossing unit has at least one stamp,
• Arranging the rotor lamination stack on a receptacle,
• Inserting the at least one magnet into the magnetic receptacle,
• Processing a Verstellweggröße and a pressure force magnitude in a control unit, wherein the Verstellweggröße represents the displacement by which the plunger and the rotor core stack move towards each other due to a stroke, and wherein the pressure force size, representing the force with which the punch presses on the rotor core,
• - Controlling an adjustment as a function of Verstellweggröße and the pressure force size for performing the lifting movement, so that the stamp penetrates in the region of the magnetic recording due to the lifting movement at least partially in the rotor core and the magnet is clamped by the resulting material deformation in the edge region of the magnetic recording in the magnetic recording ,

The inventive device and the method according to the invention is based on the idea of a magnet in a magnetic receptacle of a rotor laminated core without additional auxiliaries, d. H. without adhesive. Instead, the magnet is clamped by forming the rotor laminated core in the edge region of the magnet holder in this and thus secured. Consequently, eliminates the burden of dosing and positioning of the adhesive in the magnetic recordings. Furthermore, the time required for the manufacture of a rotor lamination stack or a rotor is reduced, since no time has to be spent with waiting for the adhesive to harden. Also reduces the cost of positioning and holding of non-magnetized magnets in the magnetic recordings, since the need to be taken in terms of a curing process measures. The recycling of magnets installed in a rotor laminated core is also simpler since the magnets fastened according to the invention can be removed much more easily from the rotor core and the removed magnets are not contaminated by adhesive residues. Since the special measures required for the handling of adhesives used for bonding in view of dosing, curing and also the storage of the adhesives are required, the overall simplifies the mounting of magnets in magnetic recordings of a rotor core. The elimination of the relatively expensive adhesives reduce the cost of manufacturing a rotor and consequently for the manufacture of an electrical machine. In addition, the invention attaching a magnet in a magnetic recording despite its simplicity allows a highly reliable magnetic mounting. Another advantageous aspect is that by eliminating adhesives when attaching the magnets making the rotor laminations and thus the electrical machine is environmentally friendly overall, since no resulting from adhesives solvent are released.

The above object is therefore completely solved.

Before advantageous embodiments of the invention are presented, it is intended to set out in advance individual aspects of the fastening of magnets according to the invention in a magnetic receptacle of a rotor lamination stack.

The arranged on the receptacle rotor laminated core and the plunger are arranged or aligned with each other so that a longitudinal axis of the plunger and a surface of the rotor laminated core are orthogonal to each other, or that the longitudinal axis parallel to a surface normal to the surface of the rotor core and thus to an axial direction of Rotor laminations is. At the same time, the embossing unit on the plunger and the plunger in the embossing unit are each arranged such that a longitudinal axis of the plunger is parallel to the longitudinal axis of the plunger. Consequently, the punch penetrates into the rotor core due to the lifting movement in the axial direction. By thus introduced in the axial direction in the rotor laminated core force results in the rotor lamination stack below the punch First, a material flow in the axial direction, which leads with increasing penetration depth to a certain extent to a flow of material in the radial direction, towards the magnet to be fastened. There is thus a deformation of the rotor laminated core in both the axial and in the radial direction, wherein the deformation in the axial direction significantly stronger than in the radial direction, Preferably, the embossing unit is formed so that the punch seen in the radial direction at that edge region of the magnetic recording penetrates into the rotor core, which faces the inside of the magnet. The material flow in the radial direction then leads to the fact that the magnet rests against the side of the magnetic receptacle located in the radial direction. In other words, the magnet is pushed outward within the magnet holder and thus jammed. As a result, the magnet can be supported during operation of the electric machine due to the centrifugal forces occurring on this side. According to the invention, the magnet is fastened in the magnetic receptacle by partial reshaping of the rotor lamination stack. According to the invention, the magnet is fastened in the magnetic receptacle by forming referred to as embossing forming, for which purpose at least one embossing point is set or introduced into the rotor laminated core.

In an advantageous embodiment of the invention, the control unit is designed to control the adjustment so that the lifting movement is performed first depending on the pressure force magnitude and then, after fulfilling a predetermined for the pressure force criterion as a function of Verstellweggröße. This two-step procedure has the following advantage: The fact that the stroke movement is first carried out as a function of the pressure force size ensures that the rotor laminated core is clearly fixed with respect to the punch. At the same time this leads to the fact that it does not come to settling processes when penetrating the stamp and thus during deformation of the rotor core, which could occur due to the material transitions that exist within a rotor core, because this is composed of a plurality of individual rotor laminations. Thus, a reproducible penetration of the punch is ensured in the rotor core. By subsequently carried out as a function of Verstellweggröße lifting movement a reproducible material deformation is ensured both in the axial and in the radial direction, with a reproducible radial deformation of material in view of a reliable attachment of the magnets in the magnetic recording of great importance. Overall, this measure allows a process-reliable fastening of the magnets and at the same time ensures a high strength of the fixation of the magnets.

In a further embodiment of the aforementioned measure, the criterion is to achieve a threshold value predetermined for the compressive force quantity. This ensures that the rotor laminated core is fixed with a defined clamping force, which is also sufficiently large so that it does not come to any settling processes during the actual deformation or deformation process.

Advantageously, the adjusting unit is driven after fulfilling the predetermined criterion for the pressure force size until the adjustment size meets a predetermined criterion. Preferably, the adjusting unit is actuated until the plunger and the rotor laminated core have moved toward one another by a predetermined adjustment path due to the lifting movement which is subsequently carried out to fulfill the criterion specified for the compressive force variable.

In a further embodiment of the invention, the adjusting unit is adapted to move the plunger. The fact that the plunger and not the rotor laminated core is moved, the point at which the punch penetrates into the rotor core, can be set more accurately, because the plunger with the embossing unit arranged thereon can be moved more precisely and thus with a smaller deviation than the recording with the rotor core stacked thereon. Thus, the penetration points or penetration points with respect to the edge region of the magnetic recording can be positioned more accurately, resulting in a more reliable and thus more reproducible mounting the magnet in the magnetic recording.

Consequently, in the above-mentioned embodiment, the device has a displacement sensor which is designed to detect the adjustment path which the tappet covers due to the lifting movement. This measure makes it possible in a simple manner to determine the adjustment path by which the plunger and the rotor laminated core move towards each other, more precisely, by which the plunger is moved towards the rotor laminated core. Since the embossing unit is firmly connected to the plunger, and the punch is in turn firmly connected to the embossing unit, the adjustment path, which covers the plunger, at the same time corresponds to the path traveled by the stamp. Consequently, in a simple manner, the penetration depth of the punch can be detected in the rotor core and thus monitored. Alternatively, compliance with a predetermined penetration depth can also be ensured by, for example, providing a fixed stop representing the required penetration depth at the embossing unit.

In a further embodiment of the invention, the receptacle is designed as a further embossing unit. This measure makes it possible for a respective stamp to be able to penetrate both on the surface of the rotor laminated core facing the tappet and on the surface of the rotor laminations facing away from the tappet. Thus, the magnet can be fixed with a single stroke from both sides in the magnetic recording. It is not necessary to re-tighten the rotor core, resulting in short production times.

In a further advantageous embodiment, the embossing unit has a plurality of punches. Depending on the configuration of the embossing unit or arrangement of the stamp within the embossing unit, this makes it possible, for example, to simultaneously set several embossing points with only one stroke movement on a magnetic mount and thus to fasten the magnet at several points. In an alternative embodiment, it is possible to set embossing points on a plurality of magnetic recordings with only one stroke movement. It is also possible to combine both.

In a further embodiment of the invention, the embossing unit is designed such that the punch is initially hidden in the embossing unit, and only after the embossing unit is due to the lifting movement with the rotor core in contact, at least partially emerges from the embossing unit. This measure enables optimum pretensioning and thus fixing of the rotor laminated core before the actual deformation or deformation process takes place.

In an advantageous embodiment, the embossing unit has at least one spring. This allows the preload force defined and reproducible set or build. As a result, a process-reliable fastening of the magnets is achieved while ensuring a high strength of the fixation of the magnets.

In a further embodiment of the invention, the embossing unit has at least one force sensor in operative connection with the stamp. This enables a particularly precise determination of the force with which the punch presses into the rotor laminated core. This measure also results in a process-reliable fastening of the magnets with high strength of the fixation of the magnets.

Preferably, the embossing unit which is used in the device according to the invention or used in the context of the method according to the invention, the following components: a receiving element which is adapted to attach the embossing unit to a plunger or on a receptacle, a stamp holding member, on which at least one stamp is arranged, a contact element which is connected via at least one guide movably connected to the punch holding member, wherein the abutment member has an opening through which the punch can pass at least partially circumferentially, and at least one arranged between the punch holding member and the abutment member spring holding the punch holding member and the abutment member spaced from each other. The so executed embossing unit, which can also be referred to as embossing tool, on the one hand, a defined construction of the biasing force and on the other a defined penetration of the punch and thus a defined setting a penetration depth of the punch in the rotor laminated safely. Preferably, the further embossing unit is constructed identically.

As already stated, the adjusting unit is preferably designed in such a way that the plunger is moved and thus moves towards the rotor laminated core arranged on the receptacle. To implement the movement of the plunger, a corresponding activation of the adjustment unit by the control unit takes place. This activation is advantageously carried out in two stages or this activation is subdivided into two sections. In a first stage or in a first section, the control takes place as a function of the pressure force magnitude, ie the pressure force magnitude is evaluated and thus the pressure force monitored. This first stage or this first portion is over when a predetermined for the pressure force size criterion is met, especially if the pressure force size has reached or exceeded a predetermined threshold. In the adjoining second stage or in the second section, the control takes place as a function of the adjustment path, ie the Verstellweggröße is evaluated and thus monitors the adjustment. For this purpose, the Verstellweggröße is first zeroed, ie the value of the Verstellgröße, which is present at the time at which the pressure force size has reached the predetermined threshold or exceeded, is overwritten by the value zero. Then, the plunger is further moved toward the rotor laminated core until the zeroed Verstellweggröße corresponds to a predetermined value or reference value corresponding to the required or desired penetration depth of the punch in the rotor core. Overall, it can be achieved that the rotor laminated core is first compressed by the embossing unit with a defined, predetermined preload force (first step or first section) and then the plunger penetrates or retracts into the rotor core over a defined, predetermined penetration depth (second step or retraction) . second part). Preferably, the movement of the plunger is continuous, ie there is no interruption of movement in the transition from the first to the second stages or between the two sections. Furthermore, the threshold for the compressive force size is selected so that the biasing force at the end of the first step or section does not correspond to the spring force that would be generated by the spring contained in the embossing unit when the die-holding element and the abutment element abut each other.

At this point, it should be explained how the formulation used in connection with the adjustment path size is to be understood, which states that the tappet and the rotor lamination stack move toward one another due to the stroke movement. This formulation is not to be understood that inevitably both components, so the plunger and the rotor core are moved simultaneously. Rather, this formulation is intended to express that the distance between these two components is changed, which can be achieved in that at least one of the two components, so either the plunger or the rotor core is moved. However, it is also conceivable to move both components simultaneously. Preferably, however, only the plunger is moved.

Embodiments of the invention are illustrated in the drawings and will be explained in more detail in the following description. Show it:

1 the construction of a rotor of an electric machine based on two sub-figures,

2 the basic arrangement of first and second magnetic recordings in a rotor laminated core,

3 a schematic representation of the device according to the invention,

4 a schematic representation of an embossing unit used in the device according to the invention,

5 Detailed representations of first and second permanent magnets fastened in a rotor laminated core with differently arranged embossing points,

6 a further detailed representation of a fixed in a rotor laminated core with embossing points first and second permanent magnet.

1 consists of two sub-figures. subfigure 1a shows in an exploded view the essential components that make up a rotor 10 a non-illustrated electric machine is constructed. In the present exemplary embodiment, the electric machine should be a synchronous machine, in particular a hybrid synchronous machine. Usually, the rotor 10 from rotor laminations 12 built, wherein in the rotor laminations 12 each permanent magnet 14 are used. The rotor laminations 12 In turn, each of a plurality of (not shown) rotor laminations are constructed. The rotor laminations 12 are between two support discs 16 arranged. The rotor laminations 12 and the support disks 16 be with each other by screws 18 and associated nuts 20 connected. One screw each 18 and a mother 20 together form a connecting element. subfigure 1b shows the assembled rotor 10 ,

In 2 is a rotor core 12 shown. The rotor core 12 has magnetic recordings 22 which are also known as caverns or magnetic bags. The magnetic recordings 22 are designed in two ways: as the first magnetic recordings, one of which is exemplified by the reference numeral 22a is designated, and as a second magnetic recordings, one of which by way of example with the reference numeral 22b is designated. In the first magnetic recordings 22a are first permanent magnets 14a and in the second magnetic recordings 22b are second permanent magnets 14b brought in. For clarity, was in 2 on the representation of the first and second permanent magnets 14a . 14b waived. Preferably, adjacent first permanent magnets 14a a different mounting position and thus a different magnetic polarity. The same applies to the second permanent magnets 14b ,

One with the reference numeral 24 marked circle marks a partial area 26 of the rotor core 12 , which will be discussed below, in connection with those to be described 5 , in which this subregion is shown enlarged. Based on the subarea 26 the arrangement of embossing points is described, which with the device according to the invention in the field of magnetic recording 22 in the rotor core 12 are introduced.

In 3 is a device according to the invention in its entirety by the reference numeral 28 designated, wherein the device 28 a press 30 and a control unit associated therewith 32 having. The press 30 has a particular C-shaped base 34 and a stand 36 on. In the stand 36 is a pestle 38 movably mounted. At the pestle 38 is by means of a tool holder 40 an embossing unit 42 attached. The substructure 34 has a recording 44 which is adapted to receive a rotor core. 3 shows one on the recording 44 arranged rotor laminated core 46 , Furthermore, the device 28 an adjustment unit 48 , which is adapted to perform a lifting movement, thereby one Distance between the plunger 38 and the rotor core 46 to change. The lifting movement is in 3 through an arrow 50 indicated. The control unit 32 is adapted to the adjustment 48 to control what is in 3 through a connection 52 is indicated. The chosen representation in this regard should not have any limiting effect, of course, via the control unit 32 more in the press 30 contained components are controlled. Preferably, the adjustment is 48 designed to be the plunger 38 to move.

With regard to the activation of the adjustment 48 is the control unit 32 formed such that an adjustment path size and a pressure force size are processed for this purpose, wherein the driving takes place as a function of these two variables. The Verstellweggröße represents that adjustment to which the plunger 38 and the rotor core 46 move towards each other due to the lifting movement. Because the embossing unit 42 on the plunger 38 is fastened, the Verstellweggröße represented in the same way the adjustment by which the embossing unit 42 or a stamp arranged in it, to be described later on the one hand, and the rotor laminated core 46 on the other hand to move towards each other. The pressure force size represents the force with which the stamp to be described later on the rotor core 46 suppressed. As the illustration in 3 it can be seen, the device 28 a displacement sensor 54 on, which is adapted to detect the adjustment, the plunger 38 travels due to the lifting movement. On the pressure sensor, which is intended to detect said force is associated with 4 received.

The control unit 32 is adapted to the adjustment 48 to be controlled so that the lifting movement is carried out first as a function of the pressure force magnitude and then, after fulfilling a predetermined for the pressure force criterion, depending on the Verstellweggröße. The criterion may be the achievement of a threshold value for the amount of compressive force.

As the above statements show, the adjustment is 48 designed as a lifting unit, in such a way that the lifting movement of a first part movement and a subsequent to the first part movement second part movement composed, wherein the first part movement is realized depending on the pressure force magnitude and the second part movement in dependence of Verstellweggröße.

Preferably, the recording 44 designed as a further embossing unit. In this embodiment, it is possible, the rotor core 46 from both sides at the same time, ie with regard to its arrangement within the press 30 thus edit from top and bottom.

4 shows in the form of a Schittdarstellung a schematic representation of a device according to the invention 28 used embossing unit 42 , The embossing unit 42 has a receiving element 58 on, with which they attach to a pestle 38 associated tool holder 40 is attached. Thus, the embossing unit 42 at least indirectly on the plunger 38 attached. The embossing unit 42 also has a punch holding member 62 on, over a pressure plate 64 with the receiving element 58 connected is. The receiving element 58 , the pressure plate 64 and the stamp holder 62 form a first building unit 66 due to the arrangement on the plunger 38 can be referred to as upper unit.

Furthermore, the embossing unit 42 an investment element 68 on, about the embossing unit 42 during the mounting of the magnets on the rotor core 46 rests. With reference to the above nomenclature, the abutment element 68 a second or lower unit. The contact element 68 is about guides 70 , preferably at least two, movable with the punch holding member 62 connected. The guides 70 each consist of one in the stamp holder 62 arranged guide bore 72 and one with the abutment element 68 connected guide pin 74 , The investment element 68 is about screws 76 on the stamp holder 62 secured. These are the screws 76 each in screw holding elements 78 screwed in, wherein the screw holding elements 78 with the stamp holder 62 are connected. Between the screw holding elements 78 and the contact element 68 or between the punch holding member 62 and the contact element 68 are each springs 80 arranged. At the springs 80 it is a compression springs, which are preferably designed as coil springs. As shown in 4 Should it be a screw 76 comprehensive spring 80 act, ie the screw 76 is within him pen 80 arranged. However, this should not have any limiting effect. Furthermore, it is conceivable that between the contact element 68 and the punch holding member 62 only a single spring 80 is arranged. In other words, the embossing unit should be at least one spring 80 exhibit. Regardless of the number of springs actually used and their concrete configuration or arrangement within the embossing unit, the purpose of at least one spring 80 in that between the punch holding member 62 and the contact element 68 A gap 82 formed. By the at least one spring 80 are the stamp holder 62 and the contact element 68 kept spaced from each other. Preferably, the spring or springs are designed so that this biasing force of about 6 to 9.5 kN is generated.

The embossing unit 42 has at least one stamp 84 on, with its fixed end in the stamp holder 62 is attached. At the fixed end of each stamp 84 is a force sensor 86 arranged. In other words: the embossing unit 42 has at least one with the stamp 84 operatively connected force sensor 86 on. At its free end, the stamp 84 one stamp tip each 88 on. The investment element 68 has a survey 90 on, in the formed as through holes, in the contact element 68 arranged openings 92 end, through which the stamp 84 can pass through in part.

In the 4 illustrated embossing unit 42 is designed for fastening at least one magnet in a magnetic receptacle of a rotor lamination stack of a rotor of an electrical machine. For this purpose, the points on the plunger 38 arranged embossing unit 42 at least, a stamp 84 on, with the embossing unit 42 is formed such that the punch 84 in the region of a (not shown) magnetic recording due to a stroke of the plunger 38 at least partially penetrates into a (not shown) rotor laminated core and the magnet is clamped by the resulting in the edge region of the magnetic recording material deformation in the magnetic recording. For this purpose, the embossing unit 42 formed such that the punch 84 first in the embossing unit 42 is hidden, and only after the embossing unit 42 due to the lifting movement with the (not shown) rotor core in contact, at least partially from the embossing unit 42 emerges. Under the partial circumferential emergence of the stamp 84 It should be understood that at least part of the stamp tip 88 through the opening 92 from the investment element 68 protrudes.

In the 4 chosen representation, the embossing unit 42 pointing at a pestle 38 is fixed, and thus with reference to the illustration in 3 from above onto the rotor laminated core 46 is intended to have no limiting effect. This also applies to the statements made for this purpose. In a corresponding manner, these statements also apply to the case that the recording 44 is designed as a further embossing unit, and thus with reference to the illustration in 3 , the embossing unit from below onto the rotor core 46 acts. Likewise, these statements apply in the event that an embossing unit 42 at the reception 44 is attached, for example via a receiving element directly to the recording 44 or at one of the recording 44 associated tool holder. In both cases, the in 4 shown arrangement rotated by 180 °, ie the punch 84 would not like in 4 shown from top to bottom, but drive from bottom to top in the rotor core.

Also, the in 4 with respect to the force sensor selected representation have no limiting effect. According to 4 the at least one force sensor is arranged in the embossing unit. Alternatively, the force sensor can also be arranged in the press itself, for example in the region of the stator.

5 consists of five sub-figures 5a to 5e , each of which, according to the explanations to 2 , a section 26 a rotor core 12 in an enlarged view shows. Everyone in the subfigures 5a to 5e shown sections 26 each has a first magnetic recording 22a and a second magnet holder 22b on. In the first magnet recording 22a is a first permanent magnet 14a and in the second magnet recording 22b is a second permanent magnet 14b brought in. The first and second permanent magnets 14a . 14b are in the magenta shots 22a . 22b by means of embossing points 94 attached. The two permanent magnets shown 14a . 14b are arranged according to a first installation position or polarity. To these adjacent, ie arranged in an adjacent magnetic recording permanent magnets are arranged according to a second mounting position or polarity. The one in the subfigures 5a to 5e each discernible gap between the magnetic recordings and the permanent magnets should have no limiting effect. In the subfigures 5a to 5e are the embossing points 94 each shown without the caused by the embossing radial material flow, since with these sub-figures only different arrangement possibilities of the embossing points to be shown. subfigure 5a shows a previously selected arrangement of the embossing points 94 whereas the subfigures 5b to 5e new arrangements of the embossing points 94 show, which are distinguished from the previously selected arrangement in that the permanent magnets are held with a larger holding force in the Magentaufnahmen.

In subfigure 5a are both the first magnetic recording 22a associated first embossing points 94a as well as the second magnetic recording 22b associated second embossing points 94b each arranged in the region of the corners of the magnetic recordings. In terms of one for the first magnet recording 22a or the first permanent magnet 14a defined perpendicular bisectors are the first embossing points 94a very far, preferably maximally removed from this. The same applies to the second magnetic recording 22b or the second permanent magnet 14b , where from the founder of the clarity of the representation assigned to this one Mid-vertical was waived. In the subfigures 5b to 5e was also omitted for reasons of clarity on the representation of the mid-perpendicular.

In subfigure 5b are the first and second embossing points 94a . 94b further into the center area of the first and second magnetic receptacles 22a . 22b or the first and second permanent magnets 14a . 14b moved. This is the preferred arrangement of the embossing points, as in this case the force acting on the permanent magnets holding force is greatest.

In subfigure 5c is for each of the first and second magnetic recordings 22a . 22b or for each of the first and second permanent magnets 14a . 14b only an embossing point 94a . 94b provided, which is preferably arranged centrally and thus on the perpendicular bisector.

In subfigure 5d in turn are for the first and second magnetic recordings 22a . 22b or the first and second permanent magnets 14a . 14b two embossing points each 94a . 94b provided, in comparison to the one in subfigure 5b arrangement are arranged at an even closer distance to the mid-perpendicular.

In subfigure 5e a further alternative arrangement of the embossing points is shown. For the second magnetic recording 22b or the second permanent magnet 14b are the second embossing points 94b as shown in subfigure 5d arranged. In contrast, in the first magnetic recording 22a arranged first permanent magnet 14a over three first embossing points 94a fastened, of which the middle embossing point is preferably arranged on the mid-perpendicular and the two outer embossing points as shown in the subfigure 5d are arranged. The in part figure 5e shown arrangement of the second embossing points 94b is just an example. Of course, the second or the embossing points also as in the sub-figures 5b or 5c be shown shown.

As the representation in the subfigures 5b to 5e it can be seen, the permanent magnets can be fixed with a different number of embossing points in the respective magnetic recordings. As a result, an embossing unit has at least one punch relative to a magnet holder. Advantageously, with a single embossing unit both for a first magnetic recording of the arranged therein first permanent magnet, as well as for a second magnetic recording of the arranged therein second permanent magnet at the same time attached. Consequently, the embossing unit has both the first magnetic recording and the second magnetic recording associated stamp. In a preferred embodiment, the permanent magnets disposed therein are fastened at the same time with a single embossing unit both for two first magnetic recordings and for two second magnetic recordings, which means that this stamping unit has a corresponding number of stamps. With respect to the exemplary presentation in 4 This means that the embossing unit shown there is to be adjusted accordingly, depending on how many magnetic recordings at the same time the permanent magnets are to be fixed with a single stroke, or with how many embossing points per magnet recording this is to take place.

The arrangement of embossing points in relative proximity to the perpendicular bisector has the advantage that such embossing points arranged cause a lower magnetic field disturbance, because it comes to only little to no narrowing of the air gap.

6 shows a first permanent magnet 14a , which means first embossing points 94a in a first magnetic recording 22a is attached and a second permanent magnet 14b , which means second embossing points 94b in a second magnetic recording 22b is attached. In 6 are the embossing points 94a . 94b deliberately not circular. Rather, the embossing points are elliptical, wherein the large semiaxis of the ellipse is aligned orthogonal to the respective Magentaufname or to the permanent magnet arranged therein. This illustration is intended to clarify the flow of material that arises when the permanent magnets are fastened due to the penetration of the stamp into the rotor laminated core. The stamp penetrates in the axial direction in the rotor core. Thus, a force in the axial direction is introduced into the rotor core. The material flow takes place in the majority or first in the axial direction and then, ie, to a small extent in the radial direction, toward the magnet receptacle or to the permanent magnet to be fastened. The material flow in the radial direction results from the fact that due to the material flow in the axial direction, the initially moving material evades increasingly in the radial direction. By the flow of material in the radial direction is achieved that the permanent magnet bears against the outside of the magnetic recording, whereby the magnet is supported there during the operation of the electric machine due to the centrifugal forces occurring there.

At this point, the sequence of attaching permanent magnets in magnetic recordings of a rotor laminated core should be summarized again: first, at least one permanent magnet is positioned in a magnetic receptacle of a rotor laminated core, wherein the rotor laminated core is arranged on a receptacle. By means of an embossing unit arranged on a plunger, the rotor laminated core is deformed in the region of the magnetic receptacle, namely by a plunger which penetrates into the rotor laminated core in the axial direction. Preferably, the receptacle is designed as a further embossing unit or, alternatively, a further embossing unit is arranged on the receptacle, so that the deformation of the rotor lamination stack takes place in the region of the magnetic receptacle on both sides of the rotor lamination stack. With respect to one side of a magnetic receptacle, a permanent magnet may be attached to one, to two, or to a larger number of imprinting points, respectively. Preferably, the stamp tips may be cylindrical, alternatively conical or pyramidal. With the device according to the invention or the method according to the invention permanent magnets are fixed by embossing in a rotor core. The permanent magnets to be introduced into the magent receptacles can either already be magnetized or unmagnetized. If the permanent magnets to be introduced are already magnetized, then the fixing of the permanent magnets according to the invention is simplified in such a way that they automatically hold in the magnet holder during the magnetic force development due to a magnetic force development. If, however, the permanent magnets to be introduced are not magnetized, then these permanent magnets must be held by appropriate measures, and indeed until they are held due to the resulting material deformation during embossing.

As already stated, embossing points are set in the rotor laminated core simultaneously from both sides. Further preferably, this is done simultaneously for two first magnetic recordings and for two second magnetic recordings. Are the permanent magnets per magnetic recording by means of two embossing points attached (partial figures 5b or 5d ), this means that sixteen embossing points are set simultaneously with a single stroke. Advantageously, the penetration depth of a punch is less than the width of the gap formed between the contact element and the punch holding member, preferably less than 1 mm.

LIST OF REFERENCE NUMBERS

10

rotor

12

Laminated core

14

permanent magnet

16

support disc

18

screw

20

mother

22

magnetic recording

24

circle

26

subregion

28

contraption

30

Press

32

control unit

34

substructure

36

stand

38

tappet

40

tool holder

42

embossing unit

44

admission

46

Laminated core

48

adjustment

50

arrow

52

connection

54

displacement sensor

58

receiving element

62

Punch holding element

64

printing plate

66

first building unit

68

contact element

70

guide

72

guide bore

74

guide pin

76

screw

78

Screws holding element

80

feather

82

gap

84

stamp

86

force sensor

88

punch tip

90

survey

92

opening

94

embossing point

96

Perpendicular bisector

Claims (13)

Device for fastening at least one magnet ( 14 ) in a magnet holder ( 22 ) of a rotor core ( 12 . 46 ) of a rotor ( 10 ) of an electric machine, with a receptacle ( 44 ), which is adapted to the rotor core ( 46 ) at least temporarily, an adjustment ( 48 ) which is adapted to perform a lifting movement, thereby a distance between a plunger ( 38 ) and the recording ( 44 ) arranged rotor core ( 46 ), one on the ram ( 38 ) embossing unit ( 42 ), which has at least one stamp ( 84 ), wherein the embossing unit ( 42 ) is designed such that the punch ( 84 ) in the region of the magnetic recording ( 22 ) due to the lifting movement at least partially in the rotor laminated core ( 46 ) and the magnet ( 14 ) by the case in the edge region of the magnetic recording ( 22 ) resulting material deformation in the magnetic recording ( 22 ) and with a control unit ( 32 ), which is adapted to a Verstellweggröße and a compressive force size process and the adjustment unit ( 48 ) in dependence on the Verstellweggröße and the pressure force magnitude, wherein the Verstellweggröße represents that adjustment path by which the plunger ( 38 ) and the rotor core ( 46 ) move towards each other due to the lifting movement, and the pressure force magnitude represents the force with which the punch ( 84 ) on the rotor core ( 46 ) presses. Device according to claim 1, characterized in that the control unit ( 32 ) is adapted to the adjustment unit ( 48 ) so that the lifting movement is first carried out as a function of the pressure force magnitude and then, after fulfilling a predetermined for the pressure force criterion, depending on the Verstellweggröße. Apparatus according to claim 2, characterized in that it is the criterion to reach a predetermined threshold for the pressure force size. Device according to one of the preceding claims, characterized in that the receptacle ( 44 ) is formed as a further embossing unit. Device according to one of the preceding claims, characterized in that the adjusting unit ( 48 ) is adapted to the plunger ( 38 ) to move. Device according to claim 5, characterized in that the device ( 28 ) a displacement sensor ( 54 ), which is adapted to detect the displacement, which the plunger ( 38 ) travels due to the lifting movement. Device according to one of the preceding claims, characterized in that the embossing unit ( 42 ) is designed such that the punch ( 84 ) first in the embossing unit ( 42 ) and only after the embossing unit ( 42 ) due to the lifting movement with the rotor core ( 46 ) is in contact, at least partially from the embossing unit ( 42 ) emerges. Device according to one of the preceding claims, characterized in that the embossing unit ( 42 ) at least one spring ( 80 ) having. Device according to one of the preceding claims, characterized in that the embossing unit ( 42 ) at least one with the stamp ( 84 ) operatively connected force sensor ( 86 ) having. Embossing unit, which is used to attach at least one magnet ( 14 ) in a magnet holder ( 22 ) of a rotor core ( 46 ) of a rotor ( 10 ) is formed of an electrical machine, with a receiving element ( 58 ), which is adapted to the embossing unit ( 42 ) on a pestle ( 38 ) or on a recording ( 44 ), a stamp holder ( 62 ), on which at least one stamp ( 84 ) is arranged, an investment element ( 68 ), which has at least one guide ( 70 ) movable with the punch holding member ( 62 ), the abutment element ( 68 ) an opening ( 92 ), through which the punch ( 84 ) can pass through at least part of the circumference, and with at least one between the stamp holding member ( 62 ) and the contact element ( 68 ) arranged spring ( 80 ) holding the punch holder ( 62 ) and the contact element ( 68 ) spaced apart holds. Rotor core for a rotor ( 10 ) of an electrical machine in which at least one magnet ( 14 ) in a magnet holder ( 22 ) using a device ( 28 ) is attached according to one of claims 1 to 8. Electric machine comprising a rotor laminated core according to claim 11. Method for attaching at least one magnet ( 14 ) in a magnet holder ( 22 ) of a rotor core ( 12 ) of a rotor ( 10 ) of an electric machine, comprising the steps of: - arranging an embossing unit ( 42 ) on a pestle ( 38 ), wherein the embossing unit ( 42 ) at least one stamp ( 84 ), - arranging the rotor laminated core ( 46 ) on a recording ( 44 ), - introducing the at least one magnet ( 14 ) in the magnetic recording ( 22 ), Processing a Verstellweggröße and a pressure force magnitude in a control unit ( 32 ), wherein the Verstellweggröße represents that adjustment path by which the plunger ( 38 ) and the rotor core ( 46 ) due to a stroke movement towards each other, and wherein the pressure force magnitude, that force with which the punch ( 84 ) on the rotor core ( 46 ), - activating an adjustment unit ( 48 ) in dependence on the adjustment path size and the pressure force variable for performing the lifting movement, so that the punch ( 84 ) in the region of the magnetic recording ( 22 ) due to the lifting movement at least partially in the rotor laminated core ( 46 ) and the magnet ( 14 ) by the case in the edge region of the magnetic recording ( 22 ) resulting material deformation in the magnetic recording ( 22 ) is jammed.

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