PERMANENT MAGNET, METHOD FOR MAKING A PERMANENT MAGNET, ROTOR WITH A PERMANENT MAGNET AND METHOD FOR MAKING A ROTOR WITH A PERMANENT MAGNET

Abstract

Method for producing a permanent magnet from a magnetic powder (200) comprising the steps of: providing a press (100) having a die (130) with at least one press cavity (150) arranged in the die (130); providing a magnetic powder (200); filling the magnetic powder (200) into the press cavity (150); aligning the magnetic orientation of the particles of the magnetic powder (200) filled into the press cavity (150) by generating an orientation magnetic field (HOM) in the press cavity (150), wherein the orientation magnetic field (HOM) along a straight line segment running within the press cavity (150) between two endpoints (H1, H2) located on the surface of the press cavity (150) exhibits a magnetic angular dispersion (DOM) in a cross-sectional plane containing the straight line segment, the absolute magnitude of which is greater than 20° or even greater than 30°; pressing the aligned magnetic powder (200) into the press cavity (150);and sintering of the compressed magnetic powder (200) to form a powder-pressed permanent magnet; wherein at least one of the two features (a1) and (a2) is fulfilled, namely that (a1) the die (130) forms part of the wall of the press cavity (150, 150'); and a flux guide (140, 140') inserted into the die (130) forms part of the wall of the press cavity (150, 150') and, under the influence of the orientation magnetic field (HOM), has a greater magnetic polarization than the die (130); (a2) the pressing is carried out by means of a punch (110, 120) having a pressing surface (110p, 120p) which acts on the magnetic powder (110p, 120p) located in the press cavity (150, 150') during pressing;and comprising at least a first section (111) made of a first material and at least a second section (112) made of a second material different from the first material, wherein the first section (111) and the second section (112) exhibit different magnetic polarizations under the influence of the orientation magnetic field (HOM).

Description

[0001] Permanent magnets are used in a wide variety of technical fields. A key requirement is that the permanent magnets exhibit a magnetic field with a high magnetic flux density. One example of this is the magnetic flux within an air gap, such as between two poles of the same or different permanent magnets, or between a pole of a permanent magnet and an iron backplate. Examples of such applications include motors and generators. For instance, permanent magnets are frequently used in the rotors of motors and generators. Permanent magnets with high magnetic flux density are also advantageous in many other technical fields, such as magnet systems for magnetocalorics. However, conventional magnet arrangements capable of generating high flux densities are complex and therefore expensive to manufacture.

[0002] The object of the present invention is, among other things, to provide a permanent magnet and a rotor with permanent magnets with which high magnetic flux densities can be generated in a simple manner, for example in an air gap. A further object of the invention is to provide methods for manufacturing such a permanent magnet or such a rotor.

[0003] These problems are solved by a method for manufacturing a permanent magnet according to claim 1, by permanent magnets according to claims 12 and 14, by a rotor according to claim 15 or by a method for manufacturing a rotor according to claim 21. Embodiments and further developments of the invention are the subject of dependent claims.

[0004] A first aspect concerns a process for manufacturing a permanent magnet from magnetic powder. For this purpose, a press and magnetic powder are provided. The die has at least one pressing cavity arranged within it. The magnetic powder is filled into the pressing cavity, and the magnetic orientation of the particles of the filled magnetic powder is aligned by generating an orientation magnetic field within the pressing cavity. Along a straight line segment running within the pressing cavity between two endpoints located on the surface of the pressing cavity, the orientation magnetic field exhibits a magnetic angular dispersion in a cross-sectional plane containing the straight line segment, the absolute value of which is greater than 20° or even greater than 30°. The aligned magnetic powder within the pressing cavity is then compressed and subsequently sintered, resulting in a powder-pressed permanent magnet.

[0005] A second aspect concerns a permanent magnet made from a magnetic powder. The magnet has a magnetic orientation axis. Along a straight line that completely intersects the permanent magnet and is perpendicular to the magnetic orientation axis, the permanent magnet exhibits a magnetic angular dispersion of at least 20° or at least 30°.

[0006] A third aspect concerns a permanent magnet made of magnetic powder, which has plane-parallel pole surfaces and which exhibits a north-south effect at a temperature of 20°C, the strength of which has an absolute value of at least 0.18, at least 0.25 or at least 0.30.

[0007] A fourth aspect concerns a rotor equipped with one or more permanent magnets, each of which – in the case of multiple permanent magnets independently of the other permanent magnets – is designed according to the second aspect and / or according to the third aspect.

[0008] A fifth aspect concerns a method for manufacturing a rotor. For this purpose, a large number of permanent magnets are each manufactured according to a method according to the first aspect and arranged in a rotor designed according to the fourth aspect.

[0009] The invention is explained in more detail below with reference to exemplary embodiments and the accompanying figures. In the figures, identical reference numerals denote identical or corresponding elements. The figures show:

[0010] Fig. 1 a motor having a rotor equipped with permanent magnets.

[0011] Fig. 2A and Fig. 2B Permanent magnets with a strong north-south effect.

[0012] Fig. 2C the view of the magnet according to Fig. 2A with several equidistant cutting planes perpendicular to the magnetic orientation axis.

[0013] Fig. 2D view of the magnet according to Fig. 2B with several equidistant cutting planes perpendicular to the magnetic orientation axis.

[0014] Fig. 2E a perspective view of a permanent magnet projected onto a projection plane.

[0015] Fig. 2F a top view of the in Fig. 2E Projection plane shown.

[0016] Fig. 3A a vertical section through a press for the production of a magnet pressed from a magnetic powder, during the pressing process.

[0017] Fig. 3B an enlarged representation of the image in the press according to Fig. 3A compressed magnetic powder.

[0018] Fig. 4A a view of the pressing surface of the lower punch of the press according to Fig. 3A.

[0019] Fig. 4B a view of the pressing surface of the upper die of the press according to Fig. 3A.

[0020] Fig. 5A to Fig. 5F Vertical sections through various designs of lower dies, such as those that can be used in a press for the production of magnets with a strong north-south effect.

[0021] Fig. 6A and Fig. 6B Horizontal sections through various designs of lower dies, such as those that can be used in a press for the production of magnets with a strong north-south effect.

[0022] Fig. 7A and Fig. 7B Possible horizontal sections through further different designs of lower dies, such as those that can be used in a press for the production of magnets with a strong north-south effect.

[0023] Fig. 8A to Fig. 8C Schematic representations of the magnetic flux profiles when using upper dies composed of different components.

[0024] Fig. 9A and Fig. 9B another press for the production of powder-pressed permanent magnets.

[0025] Fig. 10A to Fig. 10C another press for the production of powder-pressed permanent magnets, by means of which a powder-pressed permanent magnet with a strong north-south effect can be produced using several coils.

[0026] Fig. 11A to Fig. 11D a press for the production of powder-pressed permanent magnets, by means of which two permanent magnets can be pressed simultaneously during a pressing process.

[0027] Fig. 12 a press for the simultaneous pressing of four magnets identical with respect to their geometric shape and their distribution of the magnetic field.

[0028] Fig. 13. Filling two press hollows with a magnetic powder.

[0029] Fig. 14 the orientation of the magnetic powder after a change in the relative position between the magnetic coil and the press hollows.

[0030] Fig. 15A a procedure in accordance with the Fig. 13 and Fig. 14, with which permanent magnets are produced that have a strongly inhomogeneous magnetic field.

[0031] Fig. 15B a procedure in accordance with the Fig. 13 and Fig. 14, with which permanent magnets are produced that have a strongly inhomogeneous magnetic field.

[0032] Fig. 15C according to the procedure according to Fig. 15A manufactured permanent magnets.

[0033] Fig. 15D according to the procedure according to Fig. 15B manufactured permanent magnets.

[0034] Fig. 15E a top view of the filling opening of a press cavity.

[0035] Fig. 16 a filling funnel for filling a magnetic powder into a wide press cavity.

[0036] Fig. 17 a filling funnel for filling a magnetic powder into a narrow press cavity.

[0037] Fig. 18 a filling funnel for filling a magnetic powder into two adjacent, wide press hollows.

[0038] Fig. 19 a filling funnel for filling a magnetic powder into two adjacent, narrow press hollows.

[0039] Fig. 20 an example to illustrate the concepts of “pressing in the axial field” and “pressing in the transverse field”.

[0040] Fig. 21 a motor having a rotor fitted with permanent magnets, each of the magnets having a high magnitude of magnetic angular dispersion and / or a large magnitude of north-south effect.

[0041] Fig. 22A to Fig. 22C Arrangements with two permanent magnets whose magnetization directions intersect on the north pole side of the two magnets.

[0042] Fig. 23A to Fig. 23C Arrangements with two permanent magnets whose magnetization directions intersect on the south pole side of the two magnets.

[0043] Fig. 24 a motor having a rotor fitted with permanent magnets, along the circumference of which north poles and south poles alternate, each of the north poles being formed by two magnets. MAGNETS WITH HIGH MAGNETIC ANGLE SPREAD

[0044] Fig. Figure 1 shows a schematic representation of a motor with a rotor. 1 and a stator 2 , between which there is an air gap 12 is present. The rotor 1 has an axle 15 , around which it can rotate relative to the stator. Along the circumference of the rotor1 are permanent magnets 10 , 20 arranged. The orientation of the permanent magnets 10 is chosen such that the north poles N are in the radial direction of the rotor 1 are directed outwards, while the south poles S of the axis 15 of the rotor 1 are facing each other. The permanent magnets 20 In contrast, they possess an oppositely directed magnetization, i.e., the south poles S are in the radial direction of the rotor. 1 directed outwards, while the north poles N of the axis 15 of the rotor 1 are facing each other. The permanent magnets 10 and the permanent magnets 20 are therefore along the circumference of the rotor 1 arranged so that along the circumference a North Pole N always follows a South Pole S and a South Pole S is always followed by a North Pole N. In Fig. Figure 1, as well as some other figures, shows the orientations of the magnetic orientation axes M0 of the permanent magnets, which will be explained later. 10 , 20 as well as the orientation of the local magnetization at individual points of the permanent magnets 10 , 20 schematically marked by stylized compass needles, the tips of which point towards the North Pole (N). The ends of the compass needles opposite the tips point accordingly towards the South Pole (S). Not shown in Fig. 1 are those in the stator 2 existing electric magnetic coils.

[0045] According to one aspect of the invention, it has proven advantageous to generate high magnetic flux densities in an air gap, for example the air gap mentioned above. 12 , permanent magnets 10 , 20 to use where the inside of the permanent magnet 10 , 20The existing local magnetization directions are highly inhomogeneously distributed. This inhomogeneous distribution is chosen such that, with a single, unmounted permanent magnet... 10 , 20 , i.e. a permanent magnet 10 , 20 , which is not located in an environment influencing the course of its magnetic field, the flux density measured at it at a first point, which is located on the side of the magnet that is in the installed state of the permanent magnet 10 , 20 The area facing the air gap is larger than the area opposite the first point, which is located on the side of the magnet that, in the installed state, faces away from the air gap.

[0046] The inhomogeneity of such a highly inhomogeneous distribution of local magnetization directions within a permanent magnet 10 , 20This can be determined by the angular deviations of the local magnetization directions from the direction of the magnetic orientation axis M0 of the permanent magnet in question. 10 , 20 describe what follows with reference to the Fig. 2A to Fig. 2D is explained. As a measure of the inhomogeneity of the distribution of local magnetization directions within the permanent magnet. 10 , 20 The following section discusses the “magnetic angular scattering” of a permanent magnet. 10 , 20 It was introduced. It provides a measure of how much the local magnetization directions vary in a permanent magnet.

[0047] The Fig. 2A to Fig. 2D images show cross-sectional views of permanent magnets 10 or 20 , as is the case, for example, with a permanent magnet 10 , 20 excited engine 1 according to Fig. 1 can be used. The permanent magnets 10 , 20 Each has a magnetic orientation axis M0 represented by an arrow.

[0048] In the context of the present invention, the direction of the magnetic orientation axis M0 of a permanent magnet is 10 , 20 as follows: If you bring the permanent magnet 10 , 20 When placed in a homogeneous magnetic field, the permanent magnet aligns itself 10 , 20 Provided that no forces other than those resulting from the homogeneous magnetic field act upon it, the magnet orients itself within the homogeneous magnetic field such that its magnetic orientation axis M0 runs parallel to the homogeneous magnetic field. Furthermore, the magnetic orientation axis M0 passes through the center of mass SP of the permanent magnet. 10 , 20 The orientation of the magnetic orientation axis M0 is therefore linked to the orientation of the magnet.10 , 20 bound, i.e., the magnetic orientation axis M0 is relative to the permanent magnet 10 , 20 firmly.

[0049] In the aforementioned sense, a permanent magnet is located in a "homogeneous" magnetic field if, after being placed in the magnetic field and until its spatial orientation is determined solely by the magnetic field, the permanent magnet is exclusively located in a region of space where the magnetic field has the same direction and strength at every point. Such a homogeneous magnetic field can be generated to a good approximation, for example, using a Helmholtz coil pair.

[0050] How the Fig. 2A and Fig. 2B shows a permanent magnet 10 , 20at each point S1, S2 of its volume area a local magnetization direction emerges, each represented by a stylized, white-filled compass needle, and which corresponds to the direction of the local magnetic orientation axis m1, m2 of the permanent magnet 10 , 20 at the corresponding location S1, S2. A permanent magnet located at a location S1, S2 10 , 20 The existing local magnetization direction can be relative to the permanent magnet. 10 , 20 and thus, in principle, arbitrarily oriented relative to its magnetic orientation axis M0.

[0051] At each point R of the permanent magnet 10 , 20 The local magnetic orientation direction m1, m2 present there differs from the direction of the magnetic orientation axis M0 of the entire permanent magnet. 10 , 20 a local angular deviation Φ dependent on this point R lok (R). In Fig. 2A are examples of the local angular deviations Φ for the locations R = S1 and R = S2. lok (S1) and Φ lok (S2) is shown.

[0052] An “angular dispersion” D PM a permanent magnet 10 , 20 In the sense of the present invention, the direction of a straight line G is specified, which is the magnetic orientation axis M0 of the entire permanent magnet. 10 , 20 intersects at a right angle such that the direction of the line G points towards the magnetic orientation axis M0 by a rotation of 90° in the mathematically positive sense (leftward rotation). Fig. 2C shows the permanent magnet again. 10 according to Fig. 2A in the same sectional view, but in an enlarged representation. Accordingly, it shows Fig. 2D: an enlarged representation of the permanent magnet 20 according to Fig. 2B in the same sectional view. The permanent magnet extends in the direction of line G. 10 over a length L.

[0053] In the Fig. 2C and Fig. In 2D, several mutually parallel cutting planes E are shown, which run perpendicular to the line G and parallel to the magnetic orientation axis M0 and represent the respective permanent magnets. 10 , 20 cut. This will cut the permanent magnet in question. 10 , 20 virtually into an even number n ≥ 2 partial magnets 10 i or 20 i (i = 1...n) divided, which have identical thicknesses D in the direction of the line G. To determine the angular dispersion D PM To determine the magnet size of a real magnet, this magnet or an identical reference magnet can be cut along the cutting planes E, so that the partial magnets 10 i or 20 ias individual, separate partial magnets. The cutting planes E are generally parallel to each other. One (E0) of the cutting planes E is such that it separates two half-spaces: a positive half-space HR + , which extends from the cutting plane EO in the direction of the line G and which is one half of the partial magnets 10 i or 20 i (i = 1...n / 2) contains, as well as a negative half-space HR – , which extends from the cutting plane EO in the opposite direction to the line G and which comprises the other half of the partial magnets 10 i or 20 i (i = n / 2 + 1...n) contains. The number of partial magnets 10 i or 20 i , located in the negative half-space HR – The number of partial magnets is therefore identical to the number of partial magnets. 10 i or 20 i, which are located in the positive half-space HR + condition.

[0054] In the example shown, one (E0) of the cutting planes E passes through the center of gravity SP of the magnet. 10 , 20 , which is not necessarily the case for magnets of any shape.

[0055] Each of the partial magnets 10 i or 20 i has a magnetic orientation axis M i (i = 1...n), as well as a magnetic orientation direction which, with respect to the respective magnetic orientation axis M i , from south to north of the relevant submagnet 10 i or 20 i is directed. These magnetic orientation axes M i and the associated magnetic orientation directions can be determined for the respective partial magnet 10 i or 20 iin the same way, e.g. by their alignment in a homogeneous magnetic field, which can be generated, for example, by a Helmholtz coil pair, as the magnetic orientation axis M0 for the entire permanent magnet can be determined. 10 , 20 . In the Fig. 2C and Fig. 2D is for each of the partial magnets 10 i or 20 i the magnetic orientation axis M i of the relevant partial magnet 10 i or 20 i shown, as well as the direction r pointing from south to north. M0 the magnetic orientation axis M0 of the entire permanent magnet 10 or 20 The angle Φ is also shown in each case. i (i = 1...n) between the magnetic orientation axis M0 and the projection J i the magnetic orientation axis M i of the relevant partial magnet 10 i or20 i onto a projection plane spanned by the magnetic orientation axis M0 and the line G. This projection plane is therefore identical to the representation plane of the Fig. 2C or Fig. 2D. Note that the angles Φ i (i = 1...n) on the relative orientation of the partial magnets 10 i or 20 i (i = 1...n) are to be obtained, which are the partial magnets 10 i or 20 i (i = 1...n) in the compound of the undivided permanent magnet 10 or 20 take.

[0056] Each of the angles Φ i (i = 1...n) is in the projection plane starting from the direction r M0to determine the magnetic orientation axis M0 in the mathematically positive direction of rotation (i.e., rotating counterclockwise) in an angular range from 0° to 180° inclusive, or in the mathematically negative direction of rotation (i.e., rotating clockwise) in an angular range from 0° to 180° inclusive, where the angle Φ i A rotation in the mathematically positive direction has a positive sign, and a rotation in the mathematically negative direction has a negative sign. The directions of the magnetic orientation axes M0 and M i (i = 1...n) are each oriented from south to north. If the magnetic orientation axis M0 of the entire magnet is rotated 10 or 20 to one of the partial magnets 10 i or 20 i belonging angle Φ i , so its direction (after the rotation) is identical to the direction of the orthogonal projection J. ithe associated magnetic orientation axis M i of the relevant partial magnet 10 i or 20 i to the projection plane. In Fig. For example, in 2C, angles Φ1 and Φ2 are negative, and angles Φ n-1 and Φ n positive, in Fig. In 2D, however, angles Φ1 and Φ2 are positive, and angles Φ n-1 and Φ n negative.

[0057] In accordance with the present invention, the angular dispersion D now results PM one divided into individual partial magnets 10 i=1...n or 20 i=1...n divided permanent magnets 10 or 20 as follows:

[0058] Here, Φ corresponds to i (i = 1...n) which already with reference to the Fig. 2C and Fig. 2D explained angle between the magnetic orientation axis M0 and the projection J i the magnetic orientation axis Mi of the relevant partial magnet 10 i or 20 i onto a projection plane spanned by the magnetic orientation axis M0 and the line G.

[0059] The function sign(g i – g0) is a sign function. It takes the value '+1' when the corresponding partial magnet changes. 10 i or 20 i in the positive half-space HR + is located, and the value '-1' if the associated partial magnet is located 10 i or 20 i in the negative half-space HR – is located. Here, g stands for g. i for the position of the center of gravity of the relevant partial magnet 10 i or 20 i on the line G and g0 for the position of the center of gravity SP on the line G.

[0060] The (even) number n of partial magnets 10 i or 20 iIn principle, n can be chosen arbitrarily. Preferably, n ≥ 10 or even ≥ 20.

[0061] As previously explained, the direction of line G is chosen such that, when rotated by 90° in the projection plane around its intersection point with the magnetic orientation axis M0, it maps onto the magnetic orientation axis M0. Therefore, the direction of the magnetic orientation axis M0 and the direction of line G are identical after the rotation. L = n·D. According to the preceding definition, the coordinate values ​​on line G increase in the direction of line G. The coordinate of point G2 is therefore greater than the coordinate of point G1, and also greater than the coordinate of the center of mass SP. Furthermore, the coordinate of the center of mass SP is greater than the coordinate of point G1.

[0062] The value of the magnetic angular scattering D PMThe magnetic field strength generally takes on different values ​​along various straight lines G, each perpendicular to the magnetic orientation axis M0. For example, a cuboid-shaped magnet can... 10 , 20 , whose magnetic orientation axis M0 runs parallel to its thickness direction (i.e. in the direction of the or a shortest edge length of the cuboid), in the direction of a first straight line g1 an angular scattering D PM1 possess an angular dispersion D whose magnitude is greater than 20° or greater than 30°, while along a second straight line g2, which is perpendicular to both g1 and the magnetic orientation axis M0, it exhibits an angular dispersion D PM2 may exhibit a magnitude much smaller than 20°, for example, smaller than 1°.

[0063] An alternative way to express or easily determine the inhomogeneous distribution of the magnetic field of a permanent magnet with a simple numerical value is the so-called "north-south effect." The north-south effect is suitable for magnets with the geometry of a right prism with plane-parallel pole faces (including the limiting case of a cuboid). The pole faces are defined as the two opposite flat faces of the prism, each of which intersects the magnetic orientation axis M0. The north-south effect is further explained below with reference to the following: Fig. 2A and Fig. 2B explained.

[0064] To determine the strength of the north-south effect, two points P1 and P2 are first located on the magnetic orientation axis M0 of the permanent magnet in question. 10 , 20 Definitely. Regarding permanent magnets. 10 , 20Point P1 is located on the north pole side and point P2 on the south pole side.

[0065] Along the magnetic orientation axis M0, points P1 and P2 possess the properties of the permanent magnet in question. 10 , 20 the same distance d0, which is also referred to below as the measurement distance d0. As shown by the Fig. 2E and Fig. 2F using the example of a permanent magnet 10 As explained, the orthogonal projection F P of the permanent magnet 10 onto a projection plane E perpendicular to the magnetic orientation axis M0 P a minimum width of the orthogonal projection F P to be determined. For this purpose, the (generally different) widths B10 of the orthogonal projection F are needed. P to determine each along straight lines b that lie in the projection plane E P lie and intersect the magnetic orientation axis M0. The minimum width B10 minThis corresponds to the smallest of all possible widths, B10. Fig. Figure 2E shows a perspective view of the permanent magnet. 10 and the projection plane E P with the orthogonal projection F P of the permanent magnet 10 , and Fig. 2F a top view of the projection plane E P with the orthogonal projection F P The measuring distance d0 is now chosen so that it is at least as large as the minimum width B10. min For example, the measuring distance d0 can be chosen so that it is equal to B10. min is, or such that it is at least 1.5 times B10 min amounts.

[0066] At points P1 and P2, the absolute values ​​B1 and B2, respectively, can now be determined, which represent the magnetic flux density of the object emitted by the magnets. 10 or 20The outgoing field in air radiates in the direction of the magnetic orientation axis M0. The measurements of B1 and B2 must be taken at the same temperature, e.g., room temperature (20°C). The greater the difference between the magnitudes of B1 and B2, the stronger the north-south effect. The following value serves as a measure of the strength of the north-south effect: W NS = 2*(B1 – B2) / (B1 + B2) (2).

[0067] If B1 is larger than B2, the north side N of the permanent magnet becomes 10 or 20 The opposite side, south side S, is called the "hot side," and the corresponding south side S is called the "cold side." If B2 is greater than B1, the south side S of the permanent magnet is... 10 or 20 The north side is referred to as the "hot side," and the opposite north side (N) as the "cold side." The north-south effect is more pronounced the larger the absolute value of W. NS is. If W NS(i.e., not the absolute value of W) NS If ) is greater than zero, then the hot side is located on the north side N and the cold side on the south side S of the magnet. 10 , which in Fig. 2A is shown. Conversely, W NS If the value is less than zero, then the hot side is located on the south side (S) and the cold side on the north side (N) of the magnet. 20 , which in Fig. Figure 2B illustrates this. The prerequisite for the emergence of an N / S effect in magnets that have the geometry of a right prism with plane-parallel pole faces is local deviations of the magnetic orientation direction from the magnetic orientation axis M0.

[0068] Permanent magnets 10 , 20 , where the absolute value of the angular dispersion D PM and / or the absolute value of the measure W NSThe strength of the North-South effect is significantly higher than with conventional values, and can be produced, for example, using one of the methods explained below.

[0069] For example, with such a permanent magnet 10 , 20 , which may have plane-parallel polar surfaces and may optionally have the shape of a right prism, the absolute value of W NS The measurement distance d0 must be at least 0.18 (e.g., less than or equal to -0.18 or greater than or equal to +0.18), or at least 0.25 (e.g., less than or equal to -0.25 or greater than or equal to +0.25), or at least 0.30 (e.g., less than or equal to -0.30 or greater than or equal to +0.30). The measurement distance d0 can, for example, be at least B10. min to be, or even at least 1.5·B10 min .

[0070] Alternatively or additionally, the permanent magnet can be used 10 , 20 an angular dispersion D PMexhibit, whose absolute value D PM For example, it is greater than 20° (e.g., less than -20° or greater than +20°), or even greater than 30° (e.g., less than -30° or greater than +30°). The shape of the permanent magnet is also a factor. 10 , 20 Basically, any shape is possible. For example, it can be cuboid or essentially cuboid. All of the values ​​given refer to a temperature of 20°C. PRODUCTION OF MAGNETS WITH HIGH MAGNETIC ANGLE SPREAD

[0071] The production of a permanent magnet that exhibits a high magnitude of magnetic angular dispersion D PM and / or exhibits a pronounced north-south effect, by pressing a magnetic or magnetizable powder (hereinafter also referred to as "magnetic powder") whose powder particles have been magnetically aligned in a strongly inhomogeneous magnetic field. Several examples are explained below.

[0072] Fig. Figure 3A shows an example of a press setup. 100 , with which powder-pressed permanent magnets with a large magnetic angular dispersion or a strong north-south effect can be produced, in vertical section. The press 100 includes a die 130 with a cavity 150 , which is used to hold magnetic powder to be compressed into a magnet 200 serves as a space. 150 is also referred to as "press hollow".

[0073] To press one into the press cavity 150 filled powder 200 will be a substamp 110 and / or a top stamp 120 used. The lower stamp 110 and / or the upper stamp 120 are changed relative to the die during the pressing process 130 with simultaneous compression of the powder 200 proceed parallel to the pressing direction, which in Fig. 3A is indicated by corresponding arrows. Optionally, the sub-stamp can be 110 or the upper stamp 120 opposite the die 130 be fixed, while the other stamp 120 or 110 for compressing the powder 200 relative to the die 130 is being moved.

[0074] By compressing the magnetic powder 200 This results in a single magnetic body, which can be used, for example, as a permanent magnet. 10 or 20 It can be used as described above.

[0075] The individual particles of the magnetic powder 200 Each possesses a preferred magnetic direction, the alignment of which is determined by the compression of the magnetic powder. 200 The magnetic body is fixed in place relative to the manufactured magnetic body. However, the pressing process results in a compaction of the magnetic powder. 200and consequently also a slight shift in the particles of the magnetic powder 200 relative to each other, as well as slight rotations of the particles. This means that the orientations of the preferred directions of the individual particles can change slightly during the pressing process. In the finished pressed magnet, however, the orientations of the preferred directions of the individual particles relative to each other are permanently fixed.

[0076] To produce such a pressed magnet, it is provided that the magnetic preferred directions of the particles of the powder are determined. 200 already occurs before permanent fixing, i.e., the preferred directions are aligned before and / or during pressing so that the manufactured magnetic body has a large magnetic angular dispersion D. PM or a significant north-south effect W NSexhibits. In the embodiment according to Fig. 3A Alignment is achieved using an orientation magnetic field (represented by field lines in bold), which in this example is provided by an electric coil. 161 is generated. In this example, the axis a161 of the coil runs 161 parallel to the pressing direction, i.e., the direction in which the lower punch 110 and / or the upper stamp 120 relative to the die 130 during the compression of the powder 200 The procedure will be carried out.

[0077] When the polarization of an element is mentioned below, this always refers to the magnetic polarization that the element in question exhibits under the influence of an orientation magnetic field when the element is in its intended position in the respective press. In the example according to... Fig. 3A the orientation magnetic field is passed through the coil 161generated. In principle, however, the orientation magnetic field can also be generated by any other configuration with one, two or more coils, or by one or more permanent magnets, or by a combination of one or more coils with one or more permanent magnets.

[0078] To now create a permanent magnet with a large magnetic angular dispersion D PM or a strong north-south effect in terms of magnitude W NS The present invention provides for the production of a press cavity within the press cavity. 150 or at least in the area of ​​the magnetic powder that has been filled or is to be filled but has not yet been compressed. 200 to adjust the orientation magnetic field so that the flux density is at the future hot side of the magnetic powder 200 or of the magnetic body to be produced from it, is significantly larger than on the opposite cold side.

[0079] In any case, an orientation magnetic field is generated that is present in the volume of the press cavity. 150 or in the volume range of the magnetic powder that is filled or to be filled but not yet compacted. 200 is highly inhomogeneous. Due to this orientational magnetic field, the magnetic powder located in the pressed cavity 200 magnetically aligned, i.e., each of the particles of the magnetic powder is magnetically aligned. 200 Ideally, it aligns itself with the direction of the orientation magnetic field at the location of the particle in question, provided it is not prevented from doing so by other forces. This aligns the orientation magnetic field of the particle in the pressed hollow. 150 The existing orientation magnetic field is virtually mapped onto the permanent magnet to be produced. The alignment of the particles in the pressed hollow 150 located magnetic powder 200 This occurs before and / or during the magnetic powder 200is compressed. Due to frictional forces, especially between the particles of the magnetic powder. 200 Furthermore, due to the compression caused by pressing and the associated displacement of the particles relative to each other, the orientation magnetic field is mapped onto the permanent magnet to be produced to a good approximation, but not completely identically.

[0080] As in Fig. 3B using the example of the press hollow 150 According to the press Fig. As shown in 3A, an existing orientation magnetic field H OM at any point within the volume of the press cavity 150 or at least within the volume range of the material being pressed into the hollow 150 The magnetic powder, whether already filled or to be filled, has a local orientation direction, which is represented for some locations by stylized compass needles. The orientation magnetic field H exhibits this orientation. OMalong a straight segment of a straight line H that lies within the press hollow 150 between two at the edge surface of the press cavity 150 The magnetic field direction between the endpoints H1 and H2, which depend on the specific location of the line segment, is local. The tips of the compass needles point in the magnetic north direction of the orientation magnetic field H present at the respective location. OM .

[0081] This allows for projection in a plane spanned by the line H, as well as by a line K extending in a direction r. K extends and passes perpendicularly through the midpoint H0 of the line segment, an angle θ for each point of the line segment. lok between the direction r K and determine the orthogonal projection of the local magnetic field direction onto the projection plane. The angle θ lok is in the projection plane, starting from the direction rK The local direction of the orientation magnetic field H is to be determined in the mathematically positive direction of rotation (i.e., counterclockwise) within an angular range from 0° to 180° inclusive, or in the mathematically negative direction of rotation (i.e., clockwise) within an angular range from 0° to -180° inclusive. OM is directed from south to north in each case. Based on this, a magnetic angular scattering D can be calculated as follows. OM determine the orientation magnetic field H OM along the straight section:

[0082] L is involved H the length of the straight segment of line H between points H1 and H2, where line H meets the edges of the press hollow 150 intersects, h is a coordinate on the line segment, h0 is the coordinate of the midpoint H0 of the line segment between H1 and H2, and θ lok (h) is the angle between the direction r Kand the orthogonal projection of the local magnetic field direction onto the projection plane at coordinate h. Furthermore, sign(h – h0) is a function that takes the value '+1' for h – h0 > 0, the value '–1' for h – h0 < 0, and the value '0' for h – h0 = 0.

[0083] The straight section runs inside the press cavity. 150 Optionally, the straight segment can also lie entirely within the volume area that the material enters the press cavity. 150 Magnetic powder that has been filled or is to be filled but not yet compressed 200 occupies.

[0084] The position of the straight line segment between points H1 and H2 is therefore chosen such that it lies within a volume region of the press cavity. 150 located, which is after the magnetic powder has been poured in 200 into the press cavity 150 is filled with magnetic powder (apart from unavoidable gaps between the individual particles of magnetic powder) 200After filling with magnetic powder 200 Does the straight line segment therefore intersect the magnetic powder? 200 Thus, the magnetic powder 200 along the straight line segment through the orientation magnetic field H OM magnetically aligned. A high magnetic angular scattering D is present along the straight line segment. OM of the orientation magnetic field H OM This will then affect the magnetic powder 200 depicted, i.e., the individual particles of the magnetic powder 200 are essentially parallel to the orientation magnetic field H acting locally on them OM aligned and retain this alignment after the subsequent compression of the magnetic powder 200 , apart from small displacements and rotations that occur during pressing. This allows the production of permanent magnets that exhibit a high magnetic angular dispersion, as previously explained.

[0085] In all embodiments of the invention, the orientation magnetic field H OM Optionally, the magnetic field strength can be selected such that, when magnetic powder is filled into the press cavity, it exhibits a field strength of at least 400 kA / m, at least temporarily, within the volume of the press cavity and / or within the volume of the magnetic powder itself. The orientation magnetic field is effective during compaction at least from the point at which the particles can be easily rotated until the point at which the rotatability of the particles is significantly reduced by the progress of the compaction, or until the end of the compaction. However, this does not mean that the orientation magnetic field must have a constant magnitude and / or direction during this period. Rather, it is also possible to orient the magnetic powder using several successive fields with different directions.

[0086] Furthermore, it is pointed out that the magnetic angular scattering D OM of the orientation magnetic field H OM from the choice of the position of the line H or the line segment relative to the press hollow 150 depends. An orientation magnetic field H OM Therefore, depending on the choice of the position of the line H or the line segment, different magnetic angular scattering can occur.

[0087] Furthermore, it should be noted that the line K, as shown, can but does not have to run in the pressing direction z. In principle, the line K can be oriented in any direction. For example, it can also run perpendicular to the pressing direction z, or form an angle with the pressing direction z of more than 0° and less than 90°.

[0088] To produce a permanent magnet with a strong N / S effect or with strong magnetic angular scattering D OM can the orientation magnetic field H OMfor example, it can be adjusted so that it is in the press cavity 150 a magnetic angular scattering D OM exhibits an magnitude greater than 20°, or even greater than 30°.

[0089] In Fig. 3A schematically shows the path through the magnetic field H OM the orientation coil 161 caused magnetic flux within the magnetic powder 200 This is illustrated by bold flow lines. As can be seen, the flow lines on the hot side to be produced (here, on the lower die) 110 side facing the magnetic powder 200 or the press hollow 150 ) a greater density than on the cold side to be produced (here on the upper die) 120 side facing the magnetic powder 200 or the press hollow 150 ).

[0090] One possibility within the press cavity 150or within the volume range that the material enters the press cavity 150 filled or to be filled magnetic powder 200 occupies a strongly inhomogeneous orientational magnetic field H OM To create it, optionally, the walls of the press cavity 150 to form segments which are under the influence of the orientation magnetic field H OM They exhibit different magnetic polarizations. These polarizations depend on the permeability, the field strength of the orientational magnetic field H. OM and depends on the saturation polarization of the material from which the respective section is formed.

[0091] One of these walls could be the pressing surface. 110p of the substamp 110 deal with another wall to create a pressure surface 120p of the upper stamp 120 As a pressing surface 110p of the substamp 110 This process involves the press hollow 150facing side of the lower stamp 110 viewed, which are located within the matrix 130 trained guide channel for guiding the lower die 110 is located. Accordingly, it is used as a pressing surface. 120p of the upper stamp 120 the press hollow 150 facing side of the upper stamp 120 viewed, which are located within the matrix 130 trained guide channel for guiding the upper die 120 is located. Fig. 4A shows a top view of the pressing surface. 110p of the substamp 110 , Fig. 4B a top view of the pressing surface 120p of the upper stamp 120 .

[0092] In the example according to Fig. 3A is the sub-stamp 110 from at least two sections 111 , 112composed of elements that exhibit different magnetic polarizations under the influence of an orientation magnetic field and can therefore influence the course of the magnetic flux. The arrangement of the different components 111 , 112 can be chosen in such a way that – as in Fig. 4A is shown – each of the at least two different sections 111 , 112 a part of the pressing surface 110p of the substamp 110 forms a section of the pressing surface. 110p is through a surface section 111p of the section 111 formed, another section 112p through a surface section 112p of the section 112 .

[0093] The materials for the sections 111 , 112 of the substamp 110 can optionally be selected so that one of these sections 111 , 112under the influence of an orientation magnetic field H OM a higher or, alternatively, – as for example in Fig. 3A is shown – exhibiting a lower polarization than the other (if the substamp 110 (only has two parts) or as another (if the substamp 110 (more than two sections) of the sections 111 , 112 under the influence of the same through the coil 161 generated orientation magnetic field H OM If the pressing surface 110p of the substamp 110 from the surface sections 111p , 112p of two or more such sections 111 , 112 The composition may optionally include the area proportion of that which forms the pressing surface. 110p forming the sections 111 , 112 , that of all these sections 111 , 112 under the influence of an orientation magnetic field HOM exhibiting the greatest polarization in magnitude, at the pressing surface 110p The pressing area must be greater than or equal to 20%, and / or less than or equal to 80%. To determine the pressing area, the actual area must be used, and not its projection onto a plane perpendicular to the pressing direction, for example. This is particularly important for designs where the pressing area 110p It is not even.

[0094] As also in Fig. As shown in 3A, the upper die (located here on the cold side to be produced) can 120 or – as in Fig. 4B is shown – at least its pressing surface. 120p optionally consist of a uniform material which, under the influence of an orientation magnetic field H OM exhibits low magnetic polarization or is non-magnetic. Alternatively, the upper die could also be used. 120have a two- or multi-part structure, as already used for the lower stamp 110 was explained. The substamp 110 Conversely, the properties of the present upper die would then be affected. 120 .

[0095] As further in Fig. As shown in 3A, a substamp composed of two or more different materials can be used in addition to or as an alternative to a substamp. 110 and / or upper stamp 120 also one or more magnetic flux guides 140 are used which are under the influence of an orientation magnetic field H OM exhibit a different magnetic polarization than the die 130 . Such river diversion structures 140 They also serve to determine the course of the magnetic flux in the area containing the powder. 200 filled press cavity 150 to influence favorably. In the example shown, this is / are the river guide pieces. 140 into the die 130used. Optionally, the river guide piece(s) can be used. 140 in the die 130 be interchangeable, so that the same die can be used 130 by using different river guide pieces 140 Magnets with different magnetic angular dispersion D PM or can be produced with varying degrees of north-south effect. The river conduit(s). 140 They can optionally be made from a uniform, homogeneous material. However, it is also possible to manufacture one, several, or all of the river guide pieces from a single, homogeneous material. 140 to be assembled from various sections, at least two of which are under the influence of an orientation magnetic field H OM exhibit different magnetic polarizations, as already exemplified by the sub-sections 111 , 112 of the substamp 110 This was explained. Furthermore, an optional magnetic feedback loop is available.145 , for example made of iron, which will form the river channel 140 or the river diversions 140 with the understamp 110 magnetically couples.

[0096] At the in Fig. In the example shown in 3A, the hot side of the magnetic body to be manufactured is located at the bottom die. 110 side facing the press cavity 150 or the magnetic powder contained therein 200 produced. The multi-part lower stamp 110 is therefore designed in such a way that the pressed hollow 150 or the magnetic powder contained therein 200 facing side of the lower stamp 110 in the area of ​​the first section 111 exhibits a lower magnetic flux density than in the area of ​​the section 112 This can be achieved in particular by ensuring that the first section 111 under the influence of an orientation magnetic field H OMexhibits a lower magnetic polarization than the second section 112 under the influence of the same orientation magnetic field H OM For example, the first section can 111 be non-magnetic, and / or the second part 112 can be influenced by a coil 161 generated orientation magnetic field H OM and exhibit a magnetic polarization of more than 0.8 T or more than 1.5 T at a pressing temperature of, for example, 20°C. Materials are considered “non-magnetic” within the meaning of this application if, at the pressing temperature of the relevant component under the influence of a magnetic field of strength of 800 kA / m, they exhibit a polarization of less than 0.1 T. This corresponds, for example, to a permeability of μ = 1.1 if the material has a linear magnetization curve, or to a maximum alpha-Fe content of approximately 5% in an otherwise “non-magnetic” steel.

[0097] Regardless, the upper stamp 120 , since in the present example this is located on the cold side of the magnetic body to be produced, under the influence of an orientation magnetic field H OM exhibit low magnetic polarization, for example less than 0.4 T, or be non-magnetic.

[0098] Accordingly, one, several, or each of the river guide pieces can also be used. 140 during the pressing process under the influence of an orientation magnetic field H OM exhibit a magnetic polarization that is higher than the magnetic polarization of the matrix 130 For example, one, several, or each of the river guide pieces can be used. 140 under the influence of an orientation magnetic field H OM exhibit a magnetic polarization that is at least 0.8 T or at least 1.5 T greater than the magnetic polarization of the matrix 130For example, one, several, or each of the river guide pieces can be used. 140 under the influence of an orientation magnetic field H OM and exhibit a magnetic polarization of more than 0.8 T or more than 1.5 T at a pressing temperature of, for example, 20°C, and / or the die 130 can under the influence of the orientation magnetic field H OM exhibit a magnetic polarization of less than 0.4 T or less than 0.1 T.

[0099] The values ​​mentioned in the preceding embodiment also apply in principle to all other embodiments of the invention, in particular to any other presses.

[0100] The Fig. 5A to Fig. Figure 5F shows examples of various possible designs of a sub-stamp. 110 , as in any press for the production of magnets with a high magnitude of magnetic angular dispersion D PMor can be used with a strong north-south effect, using the example of Fig. 3A explained to the press 100 . As far as the following description of this sub-stamp applies 110 on the magnetic polarization of the relevant sub-punch 110 or a section thereof 111 , 112 , 113 When reference is made to this, this information refers to the polarization that is present in the relevant substamp. 110 or in the relevant section 111 , 112 , 113 sets when the associated sub-stamp 110 in the press 100 is used and the orientation magnetic field H is applied to it OM It works. Provided that a sub-stamp is used. 110 various sections 111 , 112 , 113 Sections marked with the same reference symbol show, under the influence of the same orientation magnetic field H OMthe same magnetic polarization. This can be achieved in particular by ensuring that the individual components, marked with the same reference symbol, are made of the same material.

[0101] The substamp 110 according to Fig. 5A corresponds to what is already in the Fig. 3A and Fig. 4A explained sub-stamp 110 .

[0102] The in Fig. 5B shown substamp 110 differs from the substamp 110 according to the Fig. 3A, Fig. 4A and Fig. 5A by the fact that between adjacent sections 111 and 112 each one further section 113 is arranged, whose magnetic polarization is under the influence of an orientation magnetic field H OM is greater than the magnetic polarization of the part in question 113 adjacent section 111, but smaller than the magnetic polarization of the section in question 113 adjacent section 112 This allows for pressure on the pressing surface. 110p of the substamp 110 a smoother transition from flux density at the section 111p and the flux density at the section 112p This can be achieved. Such a smoother transition can advantageously reduce the risk of cracks occurring in the permanent magnet being manufactured.

[0103] Other variants that prevent an overly sudden change in the magnetic flux density at the pressing surface 110p which can be prevented, are in the Fig. 5C to Fig. 5F shown.

[0104] At the substamp 110 according to Fig. 5C will be the pressing surface 110p through another section 113 formed that the other parts 111 and 112 of the substamp 110covered. This results in an effect when the orientation magnetic field H is applied. OM to a smoothing of the magnetic polarization profile of the lower die 110 near the pressing surface 110p The smoothing effect is greatest when under the influence of the orientational magnetic field H OM the polarization of the segment 113 approximately the polarization of the magnetic powder 200 or green body (= pressed but still unsintered magnetic powder). In principle, a section can 113 However, they can also consist of a non-magnetic or very highly permeable material. The smoothing effect is due, among other things, to the fact that the fragments 111 and 112 through the section 113 , that the pressing surface 110p provides, during the pressing process of the magnetic powder 200 are spaced apart.

[0105] The in Fig. 5D shown sub-stamps 110differs from the substamp 110 according to the Fig. 3A, Fig. 4A and Fig. 5A by the fact that the press hollow 150 facing edges of the section(s) 112 , which are under the influence of an orientation magnetic field H OM exhibit a higher magnetic polarization than the sub-pieces 111 , are beveled at an angle and the section(s) 111 extend into the area between the pressing surface 110p and the phase(s).

[0106] Fig. 5E shows a similar substamp 110 , which differs from the sub-stamp 110 according to Fig. 5D differs only in that the chamfer is not angled but rounded.

[0107] In yet another one, in Fig. The example shown in 5F is the same as the example according to Fig. 5C, both the one that press hollow 150facing edges of the section(s) 112 as well as the one in the press hollow 150 facing edges of the section(s) 111 rounded chamfer and from another section 113 covered, which is attached to all of the sections 111 and 112 borders the sections 113 according to the Fig. 5C and Fig. 5Fs work in the same way and the same principles apply to them as already mentioned with reference to Fig. 5C explained the properties.

[0108] To connect different, adjacent sections 111 , 112 (see the Fig. 6A and Fig. 7A) or 111 , 112 , 113 (see the Fig. 6B and Fig. 7B) of a sub-stamp 110 mechanically connecting them can be achieved between adjacent sublayers. 111 , 112 , 113Any joining techniques can be used. For example, pinning, soldering, or dovetail joints are suitable joining techniques.

[0109] Regarding the sub-stamps 110 according to the Fig. 6A and Fig. 7A are the respective connections between the adjacent sections. 111 and 112 realized, at the sub-stamps 110 according to the Fig. 6B and Fig. 7B between the adjacent sections 111 and 113 , as well as between the adjacent sections 112 and 113 The views according to the Fig. 6A and Fig. 7A represent horizontal sections, such as those found in the section planes E1-E1, E3-E3, E4-E4, E5-E5 and E6-E6 of the Fig. 5A, Fig. 5C, Fig. 5D, Fig. 5E or Fig. 5F may be present, and the views according to the Fig. 6B and Fig. 7B represent horizontal sections, such as those found in the section plane E2-E2 of the Fig. 5B may be present.

[0110] Another possibility is to use different sections. 111 , 112 , 113 The method of joining them involves shrink-fitting. In this process, one of the parts can enclose one or more other parts in the form of a closed ring. In the example shown... Fig. 7A encloses the section 111 the section 112 ring-shaped, and in the example according to Fig. 7B encloses the section 111 the sections 112 and 113 ring-shaped, and the section 113 surrounds the section 112 .

[0111] At the substamp 110 according to the Fig. 6A and Fig. 6B encloses the outer section 111 the inner sections 112 or 112 and 113in the area of ​​the pressing surface 110p not completely. Regarding the sub-stamp 110 according to the Fig. 7A and Fig. 7B is the outermost section 111 formed as a closed ring, which encloses the inner sections 112 or 112 and 113 at least in the area of ​​the pressing surface 110p encloses in a ring shape, and the section which is also formed as a closed ring 113 surrounds the inner section 112 at least in the area of ​​the pressing surface 110p ring-shaped. This makes the pressing surface 110p formed by surface sections of at least two parts which are under the influence of an orientation magnetic field H OM exhibit different polarizations.

[0112] With the orders according to Fig. 6A and Fig. 6B magnets are produced that only move in the direction perpendicular to the interfaces between the parts.111 , 112 u. 113 a high magnitude of magnetic angular dispersion D PM or a significant N / S effect W NS have.

[0113] Regarding the sub-stamps 110 according to the Fig. 7A and Fig. 7B will be the inner section 112 or 112 and 113 from the outermost sections 111 surrounded in a ring shape. In this case, a high magnitude of magnetic angular dispersion D is observed in all directions perpendicular to the magnetic axis. PM or a significant N / S effect W NS generated.

[0114] Another influence on the course of the orientational magnetic field H OM in the area of ​​the press cavity 150 or the course of the magnetic flux in the pressed hollow 150 magnetic powder located 200 This can be determined by the material of the stamps. 110 or120 to achieve what will be shown below based on the Fig. 8A to Fig. 8C using the example of an upper die 120 This is explained, in which the course of the flow lines is schematically illustrated using bold lines. In the example according to Fig. 8A has the upper stamp 120 under the influence of an orientation magnetic field H OM a magnetic polarization that is greater than the magnetic polarization of the powder 200 and the die 130 under the influence of the same orientation magnetic field H OM In the example according to Fig. 8C is the top stamp 120 essentially non-magnetic, and those under the influence of an orientation magnetic field H OM magnetic polarization occurring in the upper die 120 is smaller than those under the influence of the same orientation magnetic field H OM magnetic polarization occurring in the die 130and the powder 200 In the example according to Fig. 8B, finally, is under the influence of an orientation magnetic field H OM magnetic polarization occurring in the upper die 120 greater than zero and greater than those under the influence of the same orientation magnetic field H OM magnetic polarization occurring in the upper die 120 according to Fig. 8C, but smaller than those under the influence of the same orientational magnetic field H OM magnetic polarization occurring in the upper die 120 according to Fig. 8A. Furthermore, it is under the influence of the same orientation magnetic field H OM occurring magnetic polarization of the upper die according to Fig. 8B similar to that under the influence of the same orientation magnetic field H OM magnetic polarization of the powder 200 .

[0115] A further development of a press 100for the production of a pressed permanent magnet with a high magnitude of magnetic angular dispersion D PM or with a strong north-south effect in terms of magnitude W NS show the Fig. 9A in horizontal section and Fig. 9B in vertical section. The view according to Fig. 9B corresponds to the one in Fig. Section plane E7 shown in 9A, the view according to Fig. 9A of the in Fig. Section plane E8 shown in 9B. The press 100 a die 130 with a pressed hollow 150 up into which a magnetic powder 200 is filled in. The orientation magnetic field H OM for aligning the individual particles of the magnetic powder 200 is achieved using two coils arranged coaxially to each other and spaced apart from each other. 161 and 162 generated, into which an optional coil core is inserted. 171 or 172is used. As this setup demonstrates, the axes a161 and a162 of the coils can be used. 161 or 162 run perpendicular to the pressing direction (z / –z). Optionally, the axes a161 and a162 can be identical.

[0116] The two coils 161 and 162 are connected in such a way that an electric current flows through them in the same direction during operation, which as a result leads to the current passing through the first coil 161 generated first partial magnetic field in the center of the first coil 161 points in the same direction as the one through the second coil 162 generated second partial magnetic field in the center of the second coil 162 The orientational magnetic field H OM This is created by the superposition of the first partial magnetic field and the second partial magnetic field. Optionally, the coils can be... 161 and 162have the same number of turns and / or are subjected to currents of the same strength during operation.

[0117] The die 130 with the press hollow 150 and into the press cavity 150 filled magnetic powder 200 is between the two coils 161 and 162 arranged. Also between the two coils 161 and 162 Two magnetic guide pieces are arranged. 140 and 141 Furthermore, an optional magnetic return path is available. 145 , for example made of iron, which forms the coil core 171 with the coil core 172 magnetically couples. The first guide piece 140 , which goes into the die 130 It is inserted, is located between the coil 161 and the press hollow 150 , and it extends in a direction perpendicular to the axes of the coils 161 , 162as well as the direction y running perpendicular to the pressing direction (z / –z) over a smaller area than the press cavity 150 This causes the magnetic flux density at the first guide piece to be 140 facing first page 151 of the press cavity 150 or the magnetic powder 200 in a section of this first page 151 locally elevated.

[0118] In contrast, the second guideline extends 141 in the same perpendicular to the axes of the coils 161 , 162 as well as the direction y running perpendicular to the pressing direction (z / –z) over a larger area than the press cavity 150 This in turn causes the magnetic flux density at the second guide piece to increase. 141 facing second side 152 of the press cavity 150 or the magnetic powder 200 in a section of this second page 152 is reduced.

[0119] As a result, the magnetic flux density on a sub-area of ​​the first side 151 assumes a maximum value that is higher than the maximum value of the magnetic flux density on the second side 152 The course of the field lines is therefore from the first side 151 to the second page 152 strongly spread out, resulting in a compressed magnet with the desired, high magnitude of magnetic angular dispersion D. PM or the desired, strongly pronounced north-south effect, if the magnetic powder 200 in the press cavity 150 with an attached orientation field (i.e., when the first coil 161 and the second coil 162 (as described, they are electrified) between the lower stamp 110 and the upper stamp 120The material is compressed. The resulting magnetic angular scattering is more pronounced in the y-direction than in the z-direction. The stamps used have, under the influence of the orientation magnetic field H, OM a magnetic polarization that is less than or equal to the polarization of the powder.

[0120] In addition to the tapering in the y-direction, the flow guide piece can 140 also be shorter in the z-direction than the height of the press cavity 150 Furthermore, the river diversion section 141 , similar to the y-direction, it should also be longer in the z-direction than the height of the press cavity. 150 Optionally, the coil core can be 172 a larger cross-section than the coil core 171 exhibiting this. With this arrangement, a magnet with a high N / S effect W can be produced. NS and / or with a high magnitude of magnetic angular dispersion D PM produce. The angular scattering D PMThe angular scatter is approximately equally pronounced in the y- and z-directions. A further increase in angular scatter in the z-direction can be achieved by using dies that are at least partially made of a material that, under the influence of the orientation magnetic field H, OM exhibits a magnetic polarization that is greater than the polarization of the die and the powder.

[0121] Another design of a press 100 for the production of a pressed permanent magnet with a high magnitude of magnetic angular dispersion D PM or with a strongly pronounced north-south effect in terms of magnitude, the Fig. 10A in horizontal section as well as Fig. 10B and Fig. 10C in vertical section. The view according to Fig. 10B corresponds to the one in Fig. Section plane E9 shown in 10A, the view according to Fig. 10C of the in Fig. Section plane E10 shown in 10A, and the view according to Fig. 10A which is in the Fig. 10B and Fig. Section plane E11 shown in 10C.

[0122] The press 100 in turn, a matrix 130 with a pressed hollow 150 up into which a magnetic powder 200 is filled in. The orientation magnetic field H OM for aligning the individual particles of the magnetic powder 200 is done by means of three coils 161 , 163 and 164 generated. The axes of the coils 161 , 163 and 164 are designated a161, a163 and a164 respectively.

[0123] The coils spaced apart 163 and 164 , into which an optional coil core is inserted 173 or 174 The components used can be arranged coaxially to each other, as shown. Furthermore, an optional magnetic feedback mechanism is available. 145 , for example made of iron, which forms the coil core 173 magnetically connected to the coil core174 magnetically couples. As this setup demonstrates, both the axis a161 of the coil can be magnetically coupled. 161 as well as the axes a163 and a164 of the coils 163 or 164 perpendicular to the pressing direction (z / –z). Furthermore, the axis a161 can be perpendicular to both the axis a163 and the axis a164.

[0124] The two coils 163 and 164 They are connected in such a way that an electric current flows through them in opposite directions during operation, which as a result leads to the current flowing through the coil. 163 generated partial magnetic field in the center of the coil 163 points in the opposite direction to that through the coil 164 generated partial magnetic field in the center of the coil 164 Optionally, the coils can 163 and 164The coils must have the same number of turns and / or be subjected to the same current during operation and / or have the same coil cross-section and / or generate the same (maximum) magnetic flux. Any two or three of these features, linked by "and / or", can be implemented in combination, or exactly one of these features can be implemented, or all of these features can be implemented.

[0125] The coil 161 It is then energized in such a way that part of the magnetic flux it generates passes through the coil. 163 and another part of the magnetic flux it generates passes through the coil 164 is guided. Optionally, these parts can be the same size and / or their sum can equal that of the coil. 161 generated flow corresponds.

[0126] The die 130 with the press hollow 150 and into the press cavity 150filled magnetic powder 200 is between the two coils 163 and 164 arranged. Into the die 130 Magnetic guide pieces are used. 140 , 143 and 144 The lead piece 140 is between the press hollow 150 and the coil 161 arranged, the guide piece 143 between the press cavity 150 and the coil 163 , and the lead piece 144 between the press cavity 150 and the coil 164 .

[0127] The lead piece 140 extends in a direction (y) that is perpendicular to the axis a161 of the coil 161 as well as perpendicular to the pressing direction (z / –z), over a smaller area than the press cavity 150 This causes the magnetic flux density at the guide piece to change. 140 facing side 151 of the press cavity 150 or the magnetic powder 200in a section of this page 151 locally elevated.

[0128] Furthermore, the coils 163 and 164 generated magnetic partial fields at least in the area of ​​the press cavity 150 and thus of the magnetic powder 200 essentially opposite each other, which in particular leads to the magnetic flux density at the guide piece 140 far side of the press cavity 150 or the magnetic powder contained therein 200 is reduced. This results in the magnetic powder exhibiting 200 The manufactured magnet exhibits a high absolute magnetic angular dispersion D. PM or a strong north-south effect in terms of magnitude, with the hot side being characterized by its leading piece 140 facing side and the cold side through its leading piece 140 The opposite side is formed.

[0129] Similar to the arrangement according to the Fig. 9A and Fig. 9B can also be used here for the river guide pieces. 140 , 143 and 144 also be shorter in the z-direction than the length of the press cavity 150 to achieve a pronounced, high-magnitude magnetic angular dispersion D in both the y- and z-directions PM to achieve.

[0130] Based on the Fig. 11A to Fig. Section 11D is explained below using an example of how to create a press. 100 during a single stroke of the press 100 simultaneously at least two, each made from a pressed magnetic powder 200 , 200' manufactured magnets can be produced, which means a significantly increased output.

[0131] The view according to Fig. 11B corresponds to the one in Fig. Section plane E12 shown in 11A, the view according to Fig. 11C of the in Fig. Section plane E13 shown in 11A, and the view according to Fig. 11A which is in the Fig. 11B and Fig. Section plane E14 shown in 11C.

[0132] The press 100 a die 130 with two spaced-apart press holes 150 and 150' on, into which each a magnetic powder to be compressed 200 or 200' is filled in. The orientation magnetic field H OM for aligning the individual particles of the two magnetic powders 200 , 200' is done by means of two coils 161 162 generated. The axes of the coils 161 and 162 are labelled a161 and a162 respectively.

[0133] The coils spaced apart 161 and 162 , into which an optional coil core is inserted 171 or 172 The components used can be arranged coaxially to each other, as shown. Furthermore, an optional magnetic feedback mechanism is available. 145 , for example made of iron, which forms the coil core 171with the coil core 172 magnetically couples. As this setup demonstrates, both the axis a161 of the coil can be magnetically coupled. 161 as well as the axis a162 of the coils 162 run perpendicular to the pressing direction (z / –z).

[0134] The two coils 161 and 162 They are connected in such a way that an electric current flows through them in the same direction during operation, which as a result leads to the current flowing through the coil. 161 generated partial magnetic field in the center of the coil 161 which points in the same direction as the one through the coil 162 generated partial magnetic field in the center of the coil 162 Optionally, the coils can 161 and 162 have the same number of turns and / or are subjected to currents of the same strength during operation.

[0135] The die 130 with the press holes 150 and 150' as well as with those in the press cavity150 , 150' filled magnetic powders 200 or 200' is between the two coils 161 and 162 arranged. Into the die 130 Magnetic flux guides are used. 140 , 140' , 142 and 143 The lead piece 140 is between the press hollow 150 and the coil 161 arranged, the guide piece 140' between the press cavity 150' and the coil 162 Furthermore, the spaced guide pieces can 142 and 143 Each of their facing sides has a terminal section. 142e or 143e exhibiting the space between the two press hollows 150 and 150' is arranged. The river guide pieces 142 and 143 can be as shown from the two press holes 150 , 150' They may be spaced apart. However, it is also possible that their end sections 142eand / or 143e up to the press holes 150 and 150' reach up and thus part of the inner wall of the press hole 150 and 150' form, which is based on the otherwise identical arrangement according to Fig. 11D is shown.

[0136] Each of the guide pieces 140 and 140' extends in a direction (y) that is perpendicular to both the axes a161 and a162 of the coils 161 or 162 as well as perpendicular to the pressing direction (z / –z), over a smaller area than the respective guide piece 140 , 140' nearest of the press holes 150 and 150' Furthermore, each of the guide pieces 140 , 140' , 142 , 143 under the influence of an orientation magnetic field H OM exhibits a magnetic polarization that is higher than the magnetic polarization of the matrix 130 and the powder 200under the influence of the same orientation magnetic field H OM , is the magnetic flux density at the guide piece 140 facing side 151 of the press cavity 150 or the magnetic powder 200 in a section of this page 151 locally increased. 140' facing side 151' of the press cavity 150' or the magnetic powder 200' in a section of this page 151' locally increased. In contrast, the guide pieces 142 and 143 on the sides facing each other 152 or 152' the press hollow 150 and 150' or the magnetic powder 200 or 200' a decrease in magnetic flux density compared to the flux density at the sides 151 and 151' .

[0137] As a result, the magnetic flux density at the guide piece 140facing first page 151 of the press cavity 150 or the magnetic powder 200 in a section of the page 151 locally increased. The maximum value of the magnetic flux density in the area of ​​the page 151 exhibits a higher value than any in the area of ​​the page 152 The magnetic flux density occurring. Accordingly, the maximum value of the magnetic flux density in the area of ​​the page can be determined. 151' exhibits higher than any in the area of ​​the page 152' The magnetic flux density occurring. The flux densities in the region of the sides 151 and 152 each within the magnetic powder 200 to determine, and the flux densities in the area of ​​the sides 151' and 152' are each within the magnetic powder 200' to determine.

[0138] Those who use such a press 100 from the powders 200 or 200'The pressed magnets each exhibit a high magnitude of magnetic angular dispersion D. PM or a large north-south effect in terms of magnitude, whereby the one from the powder 200 manufactured magnets the hot-side through the guide piece 140 facing side and the cold side through the guide piece 140 opposite side is formed, and in the case of the powder 200' manufactured magnets the hot-side through the guide piece 140' facing side and the cold side through the guide piece 140' The opposite side is formed.

[0139] In principle, it is possible during a press stroke 100 The goal is to simultaneously produce two or more identical green bodies or identical powder-pressed magnets, meaning they have geometrically identical shapes and an identical magnetic field distribution. An example of this is shown by the press. 100 according to Fig. 12. Here are in the matrix 130 four press hollows 150 , 150' , 150'' and 150''' arranged with a magnetic powder 200 , 200' , 200'' or 200''' are filled. The arrangement of the press hollows 150 , 150' , 150'' and 150''' in the die 130 is mirror-symmetric with respect to two different planes of symmetry, SE1 and SE2. These planes of symmetry, SE1 and SE2, can optionally be perpendicular to each other. The coils 161 and 162 in conjunction with the coil cores 171 and 172 as well as the river conduit sections 140 and 140'The generated magnetic field is mirror-symmetric with respect to both the plane of symmetry SE1 and the plane of symmetry SE2. This enables the production of two or more magnets that are identical and / or mirror-symmetric with respect to their geometric shape and the distribution of their magnetic field. For this purpose, the press hollows are used. 150 , 150' , 150'' and 150''' For the production of these magnets, they are also arranged in a mirror-symmetrical manner with respect to the planes of symmetry SE1 and SE2.

[0140] In the present example, the press hollow 150 with respect to the plane of symmetry SE1, mirror-symmetric to the press hollow 150' in the die 130 arranged accordingly, the press hollow 150'' with respect to the plane of symmetry SE1, mirror-symmetric to the press hollow 150''' in the die 130 arranged. Furthermore, the press hollow 150 with respect to a plane of symmetry SE2, mirror-symmetric to the press hollow 150''in the die 130 arranged, and the press hollow 150' is mirror-symmetric with respect to the plane of symmetry SE2 to the press hollow 150''' in the die 130 arranged.

[0141] In principle, two, three, four, or more magnets can be manufactured simultaneously during a single press stroke using this or a similar method. Each magnet is pressed into the press cavity. 150 , 150' , 150'' and 150''' located magnetic powder 200 , 200' , 200'' or 200''' At least one separate upper die and / or one separate lower die is used. In the case of multiple upper dies, these can be independently movable, or rigidly connected to each other and / or formed in one piece. Likewise, in the case of multiple lower dies, these can be independently movable, or rigidly connected to each other and / or formed in one piece.

[0142] Provided that at least one first permanent magnet and a second permanent magnet that is (geometrically and magnetically) symmetrical to it are produced, the course of the orientation magnetic field H OM within the press cavity for the first permanent magnet, with respect to at least one plane of symmetry (e.g. SE1 and / or SE2), from a first time point to a second time point, continuously mirror-symmetric to the course of the orientation magnetic field H. OM within the press cavity for the second permanent magnet. The first point in time is given by the moment after the magnetic powder has been filled into the respective press cavities, at which the orientation magnetic field H OMThe second point in time is determined by the end of the compression (reaching the green density) of the magnetic powder located in the two press cavities. Regarding the symmetry plane SE1, this criterion can be applied, for example, to the press cavities... 150 and 150' manufactured permanent magnets apply, and / or for use with the press hollows 150'' and 150''' permanent magnets manufactured. Regarding the plane of symmetry SE2, this criterion can be applied, for example, to those made with press hollow cores. 150 and 150'' manufactured permanent magnets apply, and / or for use with the press hollows 150' and 150''' manufactured permanent magnets.

[0143] Alternatively or in addition to mirror symmetry with respect to a first symmetry plane SE1 and / or a second symmetry plane SE2, the course of the orientation magnetic field H can be OMwithin the press cavity for the first permanent magnet, with respect to a symmetry axis SA, from the first time to the second time, there is a continuous twofold rotational symmetry to the course of the orientation magnetic field H. OM within the press cavity for the second permanent magnet. This twofold rotational symmetry with respect to the axis of symmetry SA means that the course of the orientational magnetic field H OM within the press cavity for the first permanent magnet, after a rotation of 180° around the axis of symmetry SA, the course of the (unrotated) orientation magnetic field H OM within the press cavity for the second permanent magnet. This is equivalent to the fact that the course of the orientation magnetic field H OM within the press cavity for the first permanent magnet, the orientation of the magnetic field H is mirror-symmetric with respect to the axis of symmetry SA. OMwithin the press cavity for the second permanent magnet. The axis of symmetry SA thus represents both a rotational axis and a mirror axis. The aforementioned criterion can be used, for example, for the press cavities 150 and 150''' manufactured permanent magnets apply, and / or for use with the press hollows 150' and 150'' manufactured permanent magnets.

[0144] The criteria concerning the symmetry of the orientational magnetic field H OM These are merely optional. Using the methods described here, the magnetic powder filled into each of two or more press cavities arranged in a common die can, of course, be magnetically aligned simultaneously without affecting any of the described symmetries of the orientation magnetic field H. OM is available.

[0145] Assuming the same fill quantities in the respective press cavities and the same compression force of the magnetic powder filled in each case, such symmetries of the orientation magnetic field H can be used. OM To produce permanent magnets that have the same shape and in which the permanent magnetic field they each provide exhibits the same pattern relative to the shape of the magnet. Such permanent magnets are therefore identical. This can be achieved, for example, by ensuring that both the two extrusion dies used in their production and the orientation magnetic field H are identical. OMPermanent magnets are axially symmetric about an axis of symmetry SA. However, it is also possible to produce permanent magnets that are mirror-symmetric with respect to a plane of symmetry SE1, SE2, both in terms of their shape and the permanent magnetic field they each provide. Such permanent magnets are generally not identical, although they can be.

[0146] The following will be based on the Fig. 13 and Fig. 14 explains a method for producing a powder-pressed magnet in a particularly simple way by using a coil arrangement 161 , 162 , which are used anyway to generate an orientation magnetic field H OM is available, is also used to process the magnetic powder 200 into a press cavity 150 to pour in. Fig. Figure 13 shows an example of the simultaneous filling of two press hollows. 150 , 150', which are arranged together in the same matrix, although for the sake of clarity the matrix has not been shown. Fig. Figure 14 shows, by way of example, the effect of the orientation magnetic field H OM caused magnetic alignment of the magnetic powder 200 in the press cavity closed by the upper die 150 , 150' The arrangement of the press holes 150 , 150' In the matrix, for example, this can be done as in the arrangement according to the Fig. 11A to Fig. 11C.

[0147] Fig. Figure 13 shows the arrangement during the filling of the magnetic powder. 200 into the two press holes 150 , 150' The die indicates this. 130 for each of the pressed hollows 150 , 150' a filling opening 131 or 131' A funnel, also known as a "filling shoe", is used for filling. 210used, which is located on its underside for each of the press hollows 150 , 150' has an outlet opening. Alternatively, it can also be used for any press cavity. 150 , 150' A separate filling funnel can be used. The outlet openings can optionally be opened and closed as needed via a slide (not shown) or similar device. The magnetic powder 200 It is initially located in the filling funnel 210 To the press holes 150 , 150' with the magnetic powder 200 To fill, the coil arrangement is used. 161 , 162 a filling magnetic field H F generated. The coil arrangement is located there for this purpose. 161 , 162 regarding the die 130 in a first relative position. The first relative position is chosen such that the filling magnetic field H F at the respective filling opening 131 or 131'exhibits a large gradient, through which the particles in the filling funnel 210 located magnetic powder 200 a magnetic force acts, through which the respective outlets of the filling funnel are located. 210 particles of the powder 200 into the associated press cavity 150 , 150' be driven. The filling magnetic field H F It therefore supports the filling of the press hollows. 150 , 150' with the magnetic powder 200 .

[0148] If z is the pressing direction and H Fx a transverse component of the filling magnetic field H F in a direction x perpendicular to the pressing direction z, then the product H can be used as an approximate measure of the filling force. Fx ·∂H Fx / ∂z from the transverse component H Fx and the gradient ∂H Fx / ∂dz of the transverse component H FxThe force is applied in the pressing direction z. Based on this equation, the location of the maximum filling force can be determined by measuring the field distribution in the press cavity. 150 , 150' to estimate. The "filling force" is defined as the force exerted by the filling magnetic field H. F caused, parallel to the pressing direction z onto the magnetic powder 200 The acting force is understood. Optionally, the first relative position can be chosen such that the point of maximum filling force in the pressing direction z is at the level of the filling opening. 131 , 131' The location of the maximum filling force can also be determined, for example, by measuring the filling magnetic field H. F (i.e., the measurement of its component in the z-direction) in air.

[0149] Alternatively or additionally, the location of the maximum filling force can also be determined by simulation, e.g. using finite elements, and / or by measuring the force acting on the powder, and / or by completely measuring the filling magnetic field with subsequent calculation of the resulting location of the maximum filling force.

[0150] Regardless of the method used to determine the location of the maximum filling force, it is generally advantageous if the location of the maximum force is determined by the filling magnetic field H. F The filling force is located at the top edge of the matrix.

[0151] For filling a press cavity 150 , 150' , which, perpendicular to the pressing direction z, may, for example, have an inner width (i.e., measured from inner wall to inner wall) of less than or equal to 10 mm or even less than or equal to 5 mm, but also in the case of press hollows with a larger inner width, the product μ0 2 ·H F (x)·∂HFx / ∂z at the point of maximum filling force, e.g. at least 40 T 2 / m. For example, the product can range up to 40 T. 2 / m to 50 T 2 / m. Here, μ0 denotes the vacuum permeability. μ0 = 12.566 × 10 –7 V·s / (A·m).

[0152] After the press holes 150 , 150' in this way with the magnetic powder 200 Once filled, this will be done in the respective press cavity. 150 , 150' magnetic powder located 200 with the aid of an orientation magnetic field H O aligned and, in the aligned state, pressed into a magnetic body, as previously described. The generation of the orientation magnetic field H OM This is done using the same coil arrangement. 161 , 162 , which are already used to generate the filling magnetic field H F was used. However, the coil arrangement is located161 , 162 during the magnetic alignment of the magnetic powder 200 regarding the die 130 in a second relative position different from the first relative position, which results in Fig. Figure 14 shows that, for example, to switch from the first relative position to the second relative position or back, the press can, for instance, use a position relative to the die. 130 have an adjustable yoke. This can be achieved, for example, through the coil cores. 171 or 172 be provided, and / or by one or more flux guides through which the magnetic flux to the press cavity 150 , 150' is being managed.

[0153] After filling with magnetic powder 200 into the press holes 150 , 150' can the funnel 210from the filling position so that it does not obstruct the press rams, which are used as described below. For example, the filling funnel can be 210 , unlike in Fig. 14 shown, can also be shifted in the y-direction, thereby releasing the filling openings so that there is no obstruction of the upper stamp(s). 120 , 120' comes.

[0154] As in Fig. 14 shown can be used for each of the press holes 150 , 150' a pair with a substamp 110 or 110' and a top stamp 120 or 120' These stamps must be present. 110 , 110' , 120 , 120' represent press stamps with which the material in the press hollow 150 or 150' The powder is compressed into individual magnets. Instead of a pair of stamps. 110 and 120 or 110' and 120'Each could also only have one stamp 110 or 120 or 110' or 120' per press hollow 150 or 150' be present. In any case, for each pressed hollow 150 , 150' at least one press die in a pressing direction z relative to the die 130 (shown here only schematically using dashed lines) adjustable.

[0155] Provided, as in the Fig. 13 and Fig. As shown in 14, with at least two press hollows 150 and 150' When work is carried out simultaneously, this can also be used to fill all press cavities. 150 , 150' , 150'' , 150'''The filling magnetic field used must exhibit mirror symmetry with respect to a first symmetry plane SE1 and / or a second symmetry plane SE2 throughout the entire filling process. This means that in the first relative position, the course of the filling magnetic field within the press cavity for the first permanent magnet is continuously mirror-symmetric with respect to at least one symmetry plane (e.g., SE1 and / or SE2) to the course of the filling magnetic field within the press cavity for the second permanent magnet. Regarding the symmetry plane SE1, this criterion can, for example, apply to the press cavities... 150 and 150' manufactured permanent magnets apply, and / or for use with the press hollows 150'' and 150''' permanent magnets manufactured. Regarding the plane of symmetry SE2, this criterion can be applied, for example, to those made with press hollow cores. 150 and 150'' manufactured permanent magnets apply, and / or for use with the press hollows 150' and150''' manufactured permanent magnets.

[0156] The criteria concerning the symmetry of the filling magnetic field are merely optional. Using the magnetic filling methods described here, two or more press cavities arranged in a common die can of course be filled simultaneously with magnetic powder without any of the described symmetries of the filling magnetic field being present.

[0157] When magnets have a high magnitude of magnetic angular dispersion D PM or with a strong north-south effect in terms of magnitude W NS If the products are to be manufactured, the second relative position can also be chosen so that the press hollow(s) are positioned as follows: 150 , 150' during the influence of the orientation magnetic field H OM in a highly inhomogeneous region of the orientation magnetic field H OM as exemplified in the Fig. 15A and Fig. 15B is shown. As in Fig. As shown in 15A, the press hole(s) can be used for this purpose. 150 , 150' in a symmetrical position between the coil cores 171 and 172 or the orientation magnetic field H OM are located. However, it is also the case – as exemplified in Fig. 15B shown – it is possible that this is the press hole or holes. 150 , 150' clearly outside a symmetry position between the coil cores 171 and 172 or the orientation magnetic field H OM are located in the area of ​​the press cavity(s). 150 , 150' the inhomogeneity of the orientation magnetic field H OM by one or more optional ones inserted into the die 130 deployed river guide pieces 147 be reinforced.

[0158] Fig. 15C shows a permanent magnet 10 , which is based on Fig. The procedure described in section 15A was used. Fig. 15D a permanent magnet 10 , which is based on Fig. The process described in section 15B was used. The magnetic orientation axis M0 is also shown in each case. Both permanent magnets 10 the Fig. 10 exhibit a high magnetic angular scattering D PM or a strong north-south effect.

[0159] Optionally, the permanent magnets can be used. 10 Each also has two plane-parallel polar surfaces. 101 and 102 exhibiting the magnetic orientation axis M0 perpendicular to the pole faces. 101 and 102 proceeded, which in Fig. 15C is shown, or it can – as in Fig. 15D is shown – with the surface normals N101, N102 of the polar surfaces 101 or 102Each includes a first angle γ101 in the range of 0° < γ101 < 90° and a second angle γ102 in the range of 0° < γ102 < 90°. These criteria apply not only to permanent magnets. 10 realise that exhibit a north-south effect, but also those where the north-south effect is equal to or approximately equal to zero.

[0160] The first and second angles γ101 and γ102, respectively, which occur when pressing the permanent magnet 10 through the position and orientation of the press cavity 150 , 150' in the orientation magnetic field H OM as well as optionally by using one or more river guide pieces 147 The angles can be set to, for example, greater than 0° or greater than 5°, and / or less than 20° or less than 10°. Permanent magnets 10, where the first and second angles γ101 and γ102 respectively are greater than 0° and less than 90°, can be used, for example, in arrangements such as those relating to the Fig. 22 to Fig. 24 will be explained further. One advantage of the method is that the position of one, several, or all coil cores can be selected. 171 , 172 , 173 , 174 (if any) relative to the pressed hollow(s) 150 , 150' , by using one or more magnetic flux guides 140 until 147 , as well as by the orientation of the press cavity(s) 150 , 150' , with a press 100 different types of permanent magnets 10 to produce objects that have different first angles γ101 and / or different second angles γ102. This can be achieved, for example, by one or – in any combination – several of the following measures: Inserting differently shaped flux guides into the die when pressing different grades. Inserting flux guides made of different materials into the die when pressing different grades. Selecting different positions of the press cavity in the orientation magnetic field during the magnetic alignment of the magnetic powder located in the press cavity when pressing different grades.

[0161] Based on the Fig. 13, Fig. 14 and Fig. 15A to Fig. In the manner described in section 15D, any powder-pressed permanent magnet can, in principle, be produced, provided that the desired magnet shape can be achieved with only one die. 110 or 120 can be produced that opposes a fixed die 130 works, or with two stamps acting against each other 110 , 120, i.e., with so-called "single-stage" pressing. A particular advantage of this method is that magnets with a high aspect ratio can also be produced. For example, the aspect ratio of green body height (= extent of the pressed green body parallel to the pressing direction) to preferred direction dimension (see definition below) can be at least 2.5 ÷ 1 or even at least 3.5 ÷ 1. The preferred direction dimension can optionally be less than or equal to 10 mm or even less than or equal to 5 mm. Sintering the green body into a permanent magnet increases the aspect ratio due to anisotropic shrinkage. Accordingly, a green body after sintering (i.e.,(before any subsequent mechanical processing) have an aspect ratio of at least 2.9 ÷ 1 or even at least 4.0 ÷ 1, wherein the height of the green compact sintered to form the magnet is again to be determined parallel to the direction in which the green compact was pressed. The preferred direction dimension of the magnet can, for example, be less than 8 mm or even less than 4 mm. Here, the preferred direction dimension of the green compact is defined by the arithmetic mean 〈s〉 of the opening widths s that define the filling opening. 131 in the direction of the later reference to Fig. 20 explained middle transverse direction of the orientation magnetic field H OM exhibits, which, with reference to Fig. 15E is illustrated. Fig. Figure 15E shows a top view of the filling opening. 131 the die 130 , as well as the central transverse direction the (generally locally variable) cross-components of the orientation magnetic field H OM Parallel to this central transverse direction indicates the filling opening 131 Various opening widths s are used. The arithmetic mean 〈s〉 of all these opening widths s represents the preferred direction of the green body.

[0162] After sintering and before any subsequent mechanical processing, the preferred direction dimension is in the same mean transverse direction with respect to the green body. to be determined as the arithmetic mean of the widths that the sintered magnet produced from the green body has parallel to this direction.

[0163] The magnets can be manufactured without further cutting the finished, sintered green bodies to obtain (then smaller) magnets with a high aspect ratio. High-aspect-ratio magnets can therefore be produced directly by pressing the magnetic powder and subsequent sintering without any later mechanical cutting. The problem with manufacturing high-aspect-ratio magnets lies in the fact that the press hollows 150 , 150' then they must also have a high aspect ratio, which is important for filling the press hollows 150 , 150' with the magnetic powder 200 more difficult.

[0164] The orientation magnetic field H OM The coil arrangement can, in principle, be arbitrary and oriented according to the type of magnet being manufactured. If a magnet pressed in a so-called "transverse field" is to be produced, the coil arrangement can be... 161 , 162have a coil axis which, at least in the second relative position, runs perpendicular or substantially perpendicular to the pressing direction.

[0165] The present invention enables, among other things, the production of first a first pressed permanent magnet and subsequently a second pressed permanent magnet, which have different angles γ101 and γ102, using the same die. 130 and the same coil arrangement 161 , 162 Furthermore, any method can be used for filling, magnetically aligning, and pressing the magnetic powder into the press cavity(s). The crucial point is that the orientation magnetic fields H present within the press cavity are aligned during the production of the first and second permanent magnets. OMdiffer in their orientation and / or strength. This can be determined by the different orientational magnetic fields H within the pressed hollow. OM In principle, this can be achieved through any measures.

[0166] One first measure could be to ensure that the second relative position when manufacturing the first permanent magnet is different from the second relative position when manufacturing the second permanent magnet.

[0167] A second measure could consist of adjusting the orientation magnetic field H OM during the manufacture of the first permanent magnet with regard to its strength and / or its orientation from the magnetic field H OM the manufacturing process for the second permanent magnet differs.

[0168] A third measure could consist of inserting a first flux guide piece into the die during the production of the first permanent magnet. 130is inserted, whereas during the production of the second permanent magnet, no flux guide piece is inserted into the die at the location of the first flux guide piece. 130 is used, or another, second flux guide piece that differs from the first flux guide piece in terms of its geometry and / or its magnetic saturation polarization.

[0169] A fourth measure could consist of using a first pressing die to press the first permanent magnet. 110 and a second press die to produce the second permanent magnet 110 is used, whereby the first press stamp 110 with regard to its geometry and / or with regard to its magnetic saturation polarization from the second press die 110 differs.

[0170] The measures mentioned can be applied individually or in any combination with two or more of the measures mentioned.

[0171] As already mentioned, the invention thus enables the successive production of a first and then a second permanent magnet with different first angles γ101 using the same press. 100 or the same press parts (e.g., the same press cavity, the same die, the same upper punch, the same lower punch, the same coil arrangement, or any combination thereof). The angular difference between the first angles γ101 of the first and second permanent magnets is in principle arbitrary (> 0°), it can, for example, be at least 5° or at least 10°.

[0172] Optionally, the first and second permanent magnets can also have different second angles γ102. The angular difference between the second angles γ102 of the first and second permanent magnets is, in principle, arbitrary (> 0°); it can, for example, be at least 5° or at least 10°. The following examples illustrate this. Fig. 16 to Fig. 19 more different examples of filling funnels 210 for filling a magnetic powder into a press cavity 150 or in two press hollows 150 , 150' shown.

[0173] The Fig. 16 and Fig. 17 each show a filling funnel 210 . This includes a schematic diagram of the filling funnel. 210 Press cavity to be filled with magnetic powder 150 depicted at its press hollow 150 The underside facing the filling funnel has 210 an outlet opening 211up, through which one in the filling funnel 210 the magnetic powder contained in the press cavity 150 can be introduced. Starting from the outlet opening. 211 the filling funnel indicates 210 a first section of wall 221 a wall section which extends parallel to the pressing direction z over a height b221 and which forms an angle φ with a plane E perpendicular to the pressing direction z. The angle φ can be determined via the wall section 221 vary or be constant. On the press hollow 150 far side of the first wall section 221 A second wall section closes. 222 on. The height that the filling funnel 210 Each of the following has a slant in the pressing direction z, is designated h210.

[0174] The same applies to anyone who is in the Fig. 18 and Fig. 19 shown filling funnels 210 with the difference that the funnel 210for the simultaneous filling of two press cavities spaced apart perpendicular to the pressing direction z 150 and 150' This is served by the filling funnel. 210 a first outlet opening 211 to fill the first press cavity 150 on, as well as one from the first outlet opening 211 spaced second outlet opening 211' for filling the second press cavity 150' . At each of the filling funnels 210 can the first outlet opening 211 have the same opening width b211 and the same opening shape as the second outlet opening 211' The first wall section extends parallel to the pressing direction z. 221 each over two-thirds of the height h210 of the filling funnel 210 .

[0175] The funnels 210 the Fig. 16 and Fig. 18 are used for filling press hollows 150 or 150', which have a large press cavity width b150 or b150', for example at least 7 mm each. The angle φ can be, for example, 50° in this case. In addition, the first inlet opening 211 and, if applicable, the second entrance opening 211' in a section plane parallel to the pressing direction z, have an opening width w211 or w211' which is, for example by 1 mm, smaller than the pressing cavity width b150 or b150' of the opening through the respective inlet opening. 211 or 211' filled press hollow 150 or 150' The funnel can be used for this purpose. 210 in the area of ​​its relation to the relevant press cavity 150 or 150' belonging outlet opening 211 or 211' the entrance opening 211 or 211 of the press cavity below 150 or 150'at their outer edge by a certain distance d211 or d211', for example 0.5 mm, all around the outer edge of the inlet opening 211 or 211' tower over.

[0176] The funnels 210 the Fig. 17 and Fig. 19, however, are used for filling press hollows. 150 or 150 and 150' , which have a small press cavity width b150 or b150', for example less than 7 mm. The angle φ can in this case be, for example, 70° or even more than 70°. In addition, the first inlet opening 211 and which, if applicable, the second entrance opening 211' in a section plane parallel to the pressing direction z, have an opening width w211 or w211' which is equal to the pressing cavity width b150 or b150' of the opening through the respective inlet opening. 211 or 211' filled press hollow 150 or 150' is.

[0177] With the present invention, a magnetic powder can be produced. 200 not only in the "axial field" but also in the "transverse field". Based on Fig. 20 is illustrated using the example of an enlarged section of Fig. Section 15A explains what is meant by “pressing in an axial field” and “pressing in a transverse field” within the meaning of the present invention. Basically, the orientation magnetic field H can be described as follows: OM at every point Q in the volume area of ​​the press cavity 150 to decompose into exactly two components, namely into one component H⇀ z in axial or pressing direction z and a component H⇀ q transverse (i.e. perpendicular) to the pressing direction z, where the components H⇀ q at various points in the press cavity, generally running in different directions perpendicular to the pressing direction z. For each of the components H⇀ z and H⇀ q It is now possible to calculate an average value 〈|H⇀ z |〉 the absolute amounts |H⇀z | from H⇀ z or an average value 〈|H⇀ q |〉 the absolute amounts |H⇀ q | from H⇀ q determine.

[0178] For the purposes of the present invention, “pressing in the axial field” is understood to mean when the ratio 〈|H⇀ z |〉 ÷ 〈|H⇀ q |〉 is greater than 1.

[0179] Accordingly, “pressing in the cross field” means that the ratio when the ratio 〈|H⇀ q |〉 ÷ 〈|H⇀ z |〉 is greater than 1.

[0180] In all variants of the invention, pressing can take place in both the longitudinal and transverse fields, provided that a corresponding orientation magnetic field H is present. OM is being discontinued.

[0181] Also based on Fig. 20 will be the aforementioned central transverse direction defined. In the middle transverse direction These are the average directions of the (generally locally variable) transverse components H⇀ q of the orientation magnetic field H OM , whereby the averaging is again performed over the volume range of the press cavity 150 This has been done.

[0182] Magnets 10 , 20 , which exhibit a high angular dispersion and / or a strong north-south effect, can be used in a motor or in a rotor 1 be used, as he already referred to Fig. 1 was explained. An example of this is shown Fig. 21. The magnets 10 , 20 , each of which has a magnetic angular scattering D PM can exhibit angles whose magnitude is greater than 20° or even greater than 30°, and which have a north-south effect, are thus incorporated into the rotor. 1 arranged so that their hot sides each faced the air gap 12 are facing or in the radial direction of the rotor 1are directed outwards. As a result, along the circumference of the rotor... 1 North poles and south poles are arranged alternately, with each of these north and south poles passing through the hot side of one of the magnets. 10 , 20 is formed. At least one, several, or each of the magnets. 10 , 20 It may have been manufactured using one of the methods described above. In particular, each of these magnets may 10 , 20 can be used without its geometric shape changing after the pressing and sintering of the underlying magnetic powder. 200e.g., by mechanical processing such as sawing, abrasive cutting, waterjet cutting, laser cutting, etc., the magnet is divided into several parts. Furthermore, subsequent cleaning of the surface, e.g., by sandblasting or pickling, as well as grinding or calibration grinding of the surfaces, particularly the pole faces, is possible to reduce any dimensional tolerances. Such surface treatments are not considered mechanical division of the magnet within the meaning of the present invention.

[0183] Furthermore, each of these magnets 10 , 20 formed in one piece, i.e. it is not composed of two or more separately manufactured partial magnets that are then glued together.

[0184] As illustrated by the example according to Fig. 21 can be seen, anyone along the circumference of the rotor can 1 alternating north poles and south poles arranged consecutively by exactly one of the magnets 10or 20 are formed. In contrast, the following is determined based on the Fig. 22A to Fig. 22C, Fig. 23A to Fig. 23C and Fig. 24 a motor with a rotor 1 explained, in which each one along the circumference of the rotor 1 alternating north and south poles arranged successively by two magnets 10 or 20 is formed.

[0185] Fig. 22A shows two magnets 10 1 and 10 2, each with a magnetic orientation axis a101 or a102. The two magnets 10 1 and 10 2 can, as in Fig. As shown in 22B, the magnets are arranged next to each other at a small distance d10. 10 1 and 10 2 can also be directly adjacent to each other, i.e., the distance d10 is zero in this case, which in Fig.Figure 22C illustrates this. In each of these magnetic arrangements, the directions (from south to north) of the magnetic orientation axes a101 and a102 can form an angle α greater than 0° and less than 120°, or greater than 10° and less than 120°. If the two magnetic orientation axes a101 and a102 are not parallel to each other, their directions form an angle α. This applies both when the magnetic orientation axes a101 and a102 intersect and when they are skew to each other. If they intersect, the point of intersection lies on the north pole side of each of the magnets. 10 1 and 102. If the magnetic orientation axes a101 and a102 are otherwise skew to each other, there is exactly one connecting line between them, the length of which corresponds to the (smallest) distance between the magnetic orientation axes a101 and a102. This connecting line then lies on the north pole side of each of the magnets. 10 1 and 10 2.

[0186] Accordingly, it shows Fig. 23A two magnets 20 1 and 20 2, each with a magnetic orientation axis a201 or a202. The two magnets 20 1 and 20 2 can, as in Fig. As shown in 23B, the magnets are arranged next to each other at a small distance d20. 20 1 and 20 2 can also be directly adjacent to each other, i.e., the distance d20 is zero in this case, which in Fig. 23C is shown. In each of these magnet arrangements of the Fig. 23B and Fig. 23C The directions of the magnetic orientation axes a201 and a202 can form an angle α greater than 0° and less than 120° or greater than 10° and less than 120°. If the two magnetic orientation axes a201 and a202 are not parallel to each other, their directions form an angle β. This applies both when the magnetic orientation axes a201 and a202 intersect and when they are skew to each other. If they intersect, the point of intersection lies on the south pole side of each of the magnets. 20 1 and 20 2. If the magnetic orientation axes a201 and a202 are otherwise skew to each other, there is exactly one connecting line between them, the length of which corresponds to the (smallest) distance between the magnetic orientation axes a201 and a202. This connecting line then lies on the south pole side of each of the magnets. 20 1 and 202.

[0187] The angles α and β explained above are each given by the smaller of the two angles between the respective north directions (tips of the black arrows) of the magnetic orientation axes a201 and a202. For example, the north directions of the magnetic orientation axes a201 and a202 in the Fig. 22B, Fig. 22C, Fig. 23B and Fig. 23C allows for angles of 40° and 320°. For angles α and β, the smaller value, namely 40°, should be chosen.

[0188] According to the Fig. 22A, Fig. 22B, Fig. 22C, Fig. 23A, Fig. 23B, Fig. 23C and Fig. 24 can be any of those along the circumference of the rotor 1The alternating north and south poles can also be formed from more than two individual permanent magnets, each manufactured according to one of the methods described above. Optionally, each of these permanent magnets can be placed in the rotor after the underlying magnetic powder has been pressed and sintered. 1 can be used without its geometric shape being changed by cutting or separating after pressing and sintering.

[0189] By using permanent magnets 10 , 20 , 10 1, 20 1, 10 2, 20 2 with high magnetic angular dispersion D PM and / or with a large north-south effect W NS in a rotor 1 can be placed in an air gap 12 between the rotor 1 and a stator 2The motor achieves a high spatial concentration of magnetic flux. Such a rotor 1 It can be used not only in a motor but also in a generator.

Claims

[1] Method for producing a permanent magnet from a magnetic powder ( 200 ) with the following steps: Providing a press ( 100 ), which is a die ( 130 ) with at least one in the die ( 130 ) arranged press hollow ( 150 ) exhibits; Providing a magnetic powder ( 200 ); Pouring in the magnetic powder ( 200 ) into the press cavity ( 150 ); Aligning the magnetic orientation of the particles in the press cavity ( 150 ) filled magnetic powder ( 200 ) by generating an orientation magnetic field (H OM ) in the press cavity ( 150 ), where the orientation magnetic field (H OM ) along a straight section that lies within the press cavity ( 150 ) between two on the surface of the press cavity ( 150A magnetic angular scattering (D) runs between the endpoints (H1, H2) located in a section plane that contains the line segment. OM ) exhibits an absolute value greater than 20° or even greater than 30°; Compressing the aligned magnetic powder ( 200 ) in the press cavity ( 150 ); and Sintering of the compressed magnetic powder ( 200 ) to a powder-pressed permanent magnet. [2] Method according to claim 1, wherein the magnetic angular scattering (D OM ) of the orientation magnetic field (H OM ) is given by where h is a coordinate on a first straight line (H) that contains the line segment; h0 is the coordinate of the midpoint of the line segment; L H the length of the line segment between the endpoints (H1, H2) is; Θ lok(h) in a projection plane spanned by the first line (H) and by a second line (K) that intersects the first line (H) perpendicularly at the midpoint (H0) of the line segment, forming an angle between a direction (r K ) the second line (K) and the orthogonal projection of the direction of the orientation magnetic field present at coordinate h (H) OM ) represents the projection plane; the angle θ lok (h) in the projection plane starting from the direction r K to be determined in the mathematically positive direction of rotation in an angular range from 0° to 180° inclusive, or in the mathematically negative direction of rotation in an angular range from 0° to 180° inclusive; the direction of the orientation magnetic field present at coordinate h (H OM ) is directed from south to north; sign(h – h0) takes the value '+1' for h – h0 > 0, the value '0' for h – h0 = 0, and the value '–1' for h – h0 < 0; and The integration is performed along the line segment between its endpoints (H1, H2). [3] Method according to claim 1 or 2, wherein the powder-pressed permanent magnet has a magnetic orientation axis (M0); and along a straight path that holds the permanent magnet ( 10 , 20 ) completely intersects and runs perpendicular to the magnetic orientation axis (M0), a magnetic angular scattering (D PM ) exhibits an magnitude greater than 20° or greater than 30°. [4] Method according to one of the preceding claims with a flow guide ( 140 , 140' ), which is inserted into the die ( 130 ) is used, whereby the die ( 130 ) a part of the wall of the press cavity ( 150 , 150') forms; the river diversion ( 140 , 140' ) a part of the wall of the press cavity ( 150 , 150' ) forms; the river diversion ( 140 , 140' ) under the influence of the orientation magnetic field (H OM ) has a greater magnetic polarization than the matrix ( 130 ). [5] Method according to claim 4, wherein the magnetic polarization that the flux guide ( 140 , 140' ) under the influence of the orientation magnetic field (H OM ) exhibits a magnetic polarization that is at least 700 mT greater than the magnetic polarization exhibited by the matrix at a temperature of 20°C ( 130 ) under the influence of the orientation magnetic field (H OM ) exhibits. [6] Method according to one of the preceding claims, wherein the pressing is carried out using a punch ( 110 , 120 ) takes place, the a pressing surface ( 110p , 120p) exhibits, which during pressing onto the material in the press cavity ( 150 , 150' ) located magnetic powder ( 110p , 120p ) affects; as well as at least a first section ( 111 ) from a first material and at least a second component ( 112 ) from a second material different from the first material. [7] The method of claim 6, wherein at least one of the first components ( 111 ) at least one of the second sections ( 112 ) surrounds in a ring shape. [8] Method according to one of claims 6 or 7, wherein a second component ( 112 ) in a direction perpendicular to the pressing direction (z) sandwich-like between two first sections ( 111 ) is arranged. [9] Method according to any one of claims 6 to 8, wherein the pressing surface ( 110p ) a first surface section ( 111p ) exhibits, which is formed by a first segment (111 ) is formed; and a second surface section ( 112p ) exhibits a second section ( 112 ) is formed. [10] Method according to any one of claims 6 to 9, wherein the magnetic polarization of one, several or every second segment ( 112 ) under the influence of the orientation magnetic field (H OM ) exhibits, at a temperature of 20°C is at least 700 mT greater than the magnetic polarization that characterizes all first segments ( 111 ) under the influence of the orientation magnetic field (H OM exhibit. [11] Method according to one of the preceding claims, wherein the orientation magnetic field (H OM ) into the press cavity ( 150 ) filled magnetic powder ( 200 ) within the volume range of the press cavity ( 150 ) and / or within the volume range of the material being pressed into the cavity ( 150 ) filled magnetic powder ( 200) exhibits a field strength of at least 400 kA / m, at least temporarily. [12] Permanent magnet made from a magnetic powder has a magnetic orientation axis (M0), as well as along a straight path that holds the permanent magnet ( 10 , 20 ) completely intersects and runs perpendicular to the magnetic orientation axis (M0), a magnetic angular scattering (D PM ) exhibits a magnitude of at least 20° or at least 30°. [13] Permanent magnet according to claim 12, wherein the magnetic angular scattering (D PM ) is given by equation (1), where n ≥ 10 or n ≥ 20. [14] Permanent magnet made of a magnetic powder with plane-parallel pole faces ( 101 , 102 ) possesses and exhibits a north-south effect at a temperature of 20°C, the strength of which (W NS) has an absolute value of at least 0.18, at least 0.25 or at least 0.

30. [15] Rotor, which includes one or more permanent magnets ( 10 , 20 ) exhibits, each of which is designed according to one of claims 12 to 13 and / or claim 14. [16] Rotor according to claim 15, comprising a circumference along which a plurality of north poles and a plurality of south poles are arranged alternately. [17] Rotor according to claim 16, wherein each of the north poles and / or each of the south poles is each connected by exactly one one-piece permanent magnet ( 10 , 20 ) is generated. [18] Rotor according to claim 16, wherein each of the north poles and / or each of the south poles is each connected by at least two one-piece permanent magnets ( 10 1, 10 2, 20 1, 20 2) is generated. [19] Rotor according to claim 17 or 18, wherein each of the one-piece permanent magnets ( 10 , 20 , 10 1, 10 2, 20 1, 20 2) consists of exactly one powder-pressed and sintered magnetic body that is not composed of two or more partial magnets glued together. [20] Rotor according to any one of claims 16 to 19, wherein one, several or each of the permanent magnets ( 10 , 20 ) is designed according to one of claims 12 to 13 and / or according to claim 14. [21] Method for manufacturing a rotor ( 1 ) with the following steps: Manufacturing a large number of permanent magnets ( 10 , 20 , 10 1, 10 2, 20 1, 20 2) each according to a method according to one of claims 1 to 11; Arranging the permanent magnets ( 10 , 20 , 10 1, 10 2, 201, 20 2) to a rotor designed according to one of claims 15 to 20 ( 1 ). [22] The method of claim 21, wherein the geometric shape of each of the permanent magnets ( 10 , 20 , 10 1, 10 2, 20 1, 20 2) is not divided into two or more partial magnets after pressing and sintering.

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