DE102009019977A1 - Ring magnet for rotor of electrical machine, has multiple pole regions rotating around circumferential direction, where magnetization of pole regions is asymmetrical along circumferential direction - Google Patents

Abstract

The magnet (44) has multiple pole regions (32/1-32/12) rotating around a circumferential direction (30), where magnetization of the pole regions is asymmetrical along the circumferential direction. The pole regions comprise an equal length along the circumferential direction. The magnetization of the pole regions is point symmetrical under reflection in a center of the magnet. The magnet is magnetized by a magnetization system comprising yoke segments made of aluminum, copper, non-magnetic steel, iron or ferromagnetic steel. Independent claims are also included for the following: (1) a magnetization system for magnetization of ring magnets (2) a method for magnetization of ring magnets.

Description

FIELD OF THE INVENTION

The The present invention relates to asymmetric magnetization ring magnets Use in rotors of electrical machines and corresponding Magnetizing systems and magnetization processes.

BACKGROUND AND PRIOR ART

For the magnetization of ring magnets for rotors electrical Machines are both Magnetisieranlagen with ironless Magnetisierspulen as also magnetizing coils, which are applied to a magnetic core or embedded in it, known in the art.

Magnetizing coils are often applied to a bobbin similar to a stator coil, which is formed in the manner of a stator body of an external rotor motor with grooves and poles. Single thick Magnetisierdrähte the magnetizing coil are inserted into the grooves. An example of such a magnetizing coil is in US 6,232,862 B1 shown. A similar structure for the magnetization of rotor magnets also shows the US 6,519,833 B2 , wherein in each case a plurality of windings of the magnetizing coil are introduced into the individual grooves. Another example of a magnetization method and a corresponding magnetic core magnetizing coil is shown in FIG US 4,748,535 shown. Coils which are applied to or embedded in a nonmagnetic support are referred to in the art as ironless coils or as air coils.

1a shows by way of example in development the course of the magnetization M as a function of a spatial coordinate along the circumferential line of a ring magnet, as it results using a Magnetisieranlage with ironless Magnetisierspule for two pole pairs between a point A and a point B. Pole regions 10 with positive magnetization, which correspond to a north pole of the ring magnet, change with polar regions 12 negative magnetization corresponding to a south pole of the ring magnet from. The zeros of the magnetization curve correspond to the pole boundaries 14 of the ring magnet, ie the boundary between a north pole and a south pole. The pole boundaries are arranged equidistantly along the circumferential line of the ring magnet, so that an approximately sinusoidal magnetization curve typically results, as in FIG 1a shown. The resulting magnetization curve is symmetrical with displacement along the circumferential line by a distance d, which corresponds to two pole regions, ie a pole pair, so goes on displacement along the direction x of the circumferential line by this distance d in a magnetization over, with the original magnetization curve matches. A complete agreement, ie a highly symmetric magnetization curve of the ring magnet, is preferred in the prior art in order to ensure a smooth, smooth running during operation as a rotor of an electric machine. Although a completely symmetrical magnetization process is desired, small deviations from the symmetry can not be completely avoided due to the production; Such magnetization gradients with slight deviations from the symmetry nevertheless apply in the sense of this document as symmetrical magnetization gradients.

To simplify the illustration is in 1a the magnetization curve of a ring magnet with only two north poles and two south poles is shown. For practical applications, one skilled in the art will usually resort to ring magnets having a larger number of poles. Due to the symmetrical magnetization curve, however, it is always sufficient to display a section of the magnetization, since the magnetization results in cyclical continuation in the regions which are not shown.

How out 1a can be seen, the illustrated magnetization curve in the region of the pole boundaries 14 relatively flat transitions between areas of positive and negative magnetization areas, ie between the North Pole and the South Pole. Flat transitions promote the operation of an electric machine quiet and smooth rotor, but reduce the efficiency of the machine down.

For comparison shows 1b a corresponding magnetization curve of a ring magnet, as typically results using a Magnetisierspule in conjunction with magnetic return.

A comparison of the magnetization curves of the 1a and 1b shows that using magnetizing coils with magnetic return steeper transitions of the magnetization curve at the pole boundaries 14 can be achieved. In the 1b shown magnetization shows a substantially trapezoidal course, where Polbereiche 10 positive magnetization turn a north pole of the ring magnet and pole regions 12 negative magnetization correspond to a south pole of the ring magnet. Also the in 1b illustrated magnetization curve has the above with reference to 1a described symmetry with displacement by two pole regions corresponding to a pole pair and can be thought cyclically continued.

In the 1b sometimes magnetization is also referred to as "rectangular". Although a completely rectangular magnetization is not possible. One tries, however, the so-called Pollücke 16 That is, the area of the ring magnet in which the transition from a north pole to a south pole (or vice versa from a south pole to a north pole) takes place as narrow as possible in order to increase the efficiency of equipped with such a ring magnet electric machine. In order to achieve particularly steep transitions it is possible to use magnetic inlays with inlays which attenuate the magnetic field generated by the magnetizing coil at predetermined positions. For example, inserts of copper may be used to attenuate magnetic induction behind the magnetic poles. The 2a shows schematically and in cross section a cylindrical yoke 34 along a perimeter line 24 at regular intervals arranged copper deposits 36 which forms a starting point for the invention. A similar effect can be achieved if the inner circumference of the yoke is provided with recesses at regular intervals. Similar to the in 2a Inserts also lead recesses to variations in permeability along the perimeter of the return path, thus modifying the induction produced by the magnetizing coil and imposed on the ring magnet. 2 B shows schematically and in cross section a cylindrical magneti rule conclusion 38 , whose inner circumference along the circumferential line 24 periodic recesses 40 having. To illustrate the recesses, these were not reproduced to scale.

Under Use of magnetizing coils with magnetic core and recesses with deposits, narrow pole gaps, d. H. steep transitions the magnetization between adjacent pole areas, and thus generate a high efficiency of the electric machine.

While magnetizing coils in conjunction with magnetic return pads, which may have inserts, are favorable to the reproducibility of the magnetization method and increase the efficiency of an engine equipped with such a rotor, such motors, however, are very sensitive to stator discontinuities in operation, and even more so , The steeper the transition between adjacent pole regions of the ring magnet is formed: During the rotation of a permanent magnetic rotor, which is a ring magnet with the in 1b shown magnetization gradient or a similarly steep transition between adjacent pole regions, in a stator provided with slot openings is stored by the variation of the air gap between the rotor and stator in the magnetic circuit of the motor in certain rotational angle ranges magnetic energy and released in other rotation angle ranges the previously stored energy again. To store the rotor from the outside energy must be supplied, whereby the rotor is braked. Conversely, where stored energy is released, the rotor is driving. The cogging torque or reluctance torque generated thereby upon rotation of the rotor leads to an uneven engine run, which is also called "cogging" and is perceived as very disturbing in many drive tasks. Particularly pronounced is the grooving for electrical machines, in which the number of stator teeth is integer divisible by the number of rotor poles. The grooving and his Ur things are z. B. in the published patent application DE 196 33 209 A1 described in further detail.

To reduce the grooving is from the DE 196 33 209 A1 it is known to divide the pole boundaries between two adjacent rotor poles into a plurality of pole staggered portions offset relative to one another. By suitable subdivision, additional reluctance torques can be generated upon rotation of the rotor, which can extend in antiphase to the reluctance moments which cause the grooving and can compensate for them. A disadvantage of this method called "skewing", however, is that the relatively offset pole boundary sections can cause forces in the axial direction during rotation of the rotor, which in turn disturb the uniform rotor and can also lead to undesirable noise. Although reveals the DE 196 33 209 A1 also the embodiments of Polgrenzabschnitten in which the generation of axial forces is reduced. However, these embodiments require the formation of pole boundaries with several carefully mutually shifted Polgrenzabschnitten with tight manufacturing tolerances, making high demands on the Magnetisieranlagen are made. Also in the in the DE 196 33 209 A1 Skewing presented the pole areas are arranged equidistantly along the circumference of the ring magnet and formed all Polgrenzabschnitte identical, so that in turn results in a regular, symmetrical course of the magnetization along the circumference.

It exists in view of the above-described disadvantages of PRIOR ART Need for an easy-to-manufacture ring magnet with a magnetization, which in operation as a rotor of an electric Machine ensures a noiseless, smooth running, as well as after a corresponding magnetizing system and a magnetization process.

OVERVIEW OF THE INVENTION

These Task is solved by a ring magnet with the features of claim 1 or a Magnetisieranlage with the features of Claim 10 and claim 23 and by a method for magnetization with the features of claim 27. The dependent claims refer to advantageous embodiments.

Of the present invention is the surprising finding underlying that a significant reduction of the grooving in Departure from the prior art also by a suitable asymmetric Formation of the magnetization along the circumference of a Ring magnet can achieve without thereby a significant Reduction of the efficiency of the electric machine in purchase must be taken.

One Inventive ring magnet comprises several longitudinal a circumferential direction alternating pole regions, wherein the magnetization the pole portions along the circumferential direction an asymmetry having.

Under an asymmetric course of the magnetization or the magnetic Induction in this document is a magnetization course along the circumferential direction, which of the above with reference uniform, described in the prior art, symmetrical course under displacement along the circumference, for example differs by a pole pair corresponding route.

by virtue of the asymmetric magnetization of the pole regions of the ring magnet is the occurring during its rotation relative to a grooved stator Reduced reluctance torque and minimizes grooving, without disturbing axial forces act on the rotor, which arise, for example, at an oblique magnetization. This allows a more even, Rock-free and low-noise operation of the electric machine guarantee.

Of the asymmetric magnetization curve leads in comparison to the previously known from the prior art symmetric magnetization gradients during operation of the ring magnet as a rotor of an electric machine to a noise spectrum with less sharp peaking (peaks): The asymmetric magnetization curve raises the acoustic Sidebands compared to the middle band. Due to the thereby causing distribution of the noise emission Another frequency range is the revolution of the invention Ring magnet experience has shown as quieter and more pleasant felt.

In an advantageous embodiment is the magnetization of the ring magnet with displacement along the circumferential direction asymmetrical about the length of a pole pair.

In In another embodiment, the magnetization differs in a first group of pole regions which are two adjacent ones Polar ranges includes, of a magnetization in a second group pole regions, which two successive adjacent pole regions includes.

In a development of the invention, the magnetization is different in a third group of pole regions, which are two of the second group subsequent, adjacent pole regions comprises, of the Magnetization of both the first group and the second group. The individual groups of poles can also do more or have less than two and unequal many Polbereiche.

In Departure from the prior art comprises the inventive Ring magnet thus pole regions with differently shaped magnetization curve, at least two different magnetization courses, in developments of the invention, three or more different Magnetization progressions, each predetermined sections are assigned to the ring magnet and, for example, in the steepness the flanks of the transition between adjacent poles as well can differ in the proportion of saturated areas.

Either in terms of the design of the magnetization curve as well the arrangement of groups of equal or similar magnetization along The circumferential direction of the ring magnet is within the scope of the invention a wide variation.

In In a preferred embodiment, the ring magnet is in subdivides a plurality of groups of respective successive pole regions, wherein each of the groups has a different magnetization and the groups are cyclically cycled along the circumferential direction alternate.

In another preferred embodiment, all Pole regions along the circumferential direction an equal length on.

In order to achieve a particularly uniform and quiet running of the ring magnet according to the invention during operation, it is advantageous that occurring reluctance moments compensate delocal, so that the reluctance occurring in a first position along the circumference line of a occurring at a second position Reluctance torque is compensated and cancel each other radial forces along the circumference. The present invention offers a variety of advantageous design options.

In a preferred embodiment is the resulting Magnetization of the pole regions point-symmetric under reflection at the center of the ring magnet. Under reflection at the midpoint of the ring magnet is the magnetization of the pole areas so in a magnetization over, which coincides with the original one Magnetization matches.

While a complete match is preferred can be due to production small deviations in the magnetization often only disproportionately large Efforts or not at all avoided. In this document is therefore basically under a match of magnetization in two Subareas of the ring magnet a match in the frame understood such production-related inaccuracies. Especially In this document, two magnetization courses are considered to correspond, when the relative deviations in the magnetization curve become smaller than 10% and preferably less than 5%. Whenever in this Writing symmetries or matches are described they are to be understood and interpreted in this sense.

In Another preferred embodiment is the resulting Magnetization with displacement along the circumferential direction Symmetrical by half or third circumference.

In a development of the invention is the resulting magnetization the Polbereiche symmetrically under reflection at a level, which a Axial direction of the ring magnet and the center of the ring magnet contains.

The The present invention also relates to a magnetizing system for the magnetization of ring magnets with a magnetizing coil with Magnetisierdrähten, which can be connected to a power source are, as well as a magnetic inference, which along a circumferential line of the magnetic yoke in several Inference segments is divided, and a receiving space for Recording of a ring magnet to be magnetized between the magnetizing coil and the magnetic inference. The shape and / or the Composition and / or the magnetization of the return segments arranged to have a resulting magnetic in the receiving space Induction to produce, which along a circumferential line of the receiving space has an asymmetry when the magnetizing coil is traversed by an electric current.

By asymmetric manipulation of the field increase in the return segments of the magnetic yoke can be Ring magnet with the properties and advantages described above produce.

In In a preferred embodiment, the return segments comprise Aluminum, copper or non-magnetic steel or air. In a another preferred embodiment (all or some) return segments ferromagnetic inserts. With the help of ferromagnetic inserts can be the magnetic Induction in predetermined return segments at appropriate Reinforce positions to an asymmetric resulting To produce induction.

In an alternative embodiment include the return segments Iron or ferromagnetic steel. In a further embodiment include non-magnetic (all or some) return segments Insoles. Using non-magnetic inserts The magnetic induction in the magnetization of the ring magnet adequately attenuate predetermined positions to go along the corresponding circumference an asymmetrical course of To produce induction.

The described with reference to the above embodiments Inserts can come in a variety of forms and from one Be formed variety of materials. The invention includes all Deposits that are suitable to the course of magnetic induction appropriate to manipulate along the perimeter of the recording room, in an annular magnet an asymmetric field profile of the magnetization to create.

In In a preferred embodiment, the inserts have a Cross-section, which differs from the rectangular shape. In which Cross-section is in particular a cross-sectional area, which by cutting the corresponding return segment created with an imaginary plane that runs along the circumferential direction the circumference of the magneti rule conclusion and a Axial direction of the magnetic yoke and / or the Recording room includes.

In In a preferred embodiment, the inserts have a trapezoidal cross section. In particular, you can the deposits have a diamond-shaped cross-section. By deviation from the rectangular shape can be appropriate asymmetric Create field increases.

In a further preferred embodiment, two adjacent return segments comprise differently shaped inserts and / or Deposits of different sizes and / or inserts of different composition. Variations of the inserts make it possible to create suitable asymmetries in the field course.

In Another preferred embodiment varies Width of the return segments in a direction transverse to first circumference. In particular, this direction can be about an axial direction of the magnetic yoke or the Recording space for receiving the ring magnet act.

Of the the aforementioned embodiment is based on the knowledge that is a suitable asymmetric field profile in the ring magnet in addition to or instead of the variations of the insoles as well can be generated by the fact that the return segments even be formed in appropriate forms.

In In a preferred embodiment, the return segments a trapezoidal or diamond-shaped cross-section on.

In Another preferred embodiment comprises Inference segments Recesses or recesses. Also by suitably shaped recesses or Ausnehmun conditions can be manipulate the course of magnetic induction such that the complete symmetry of the induction course along the corresponding circumference is broken.

In In a preferred embodiment, a cross-sectional area varies the recesses or recesses in a direction perpendicular to the first circumference. This can be both the axial direction the magnetic yoke or the receiving space as also about a direction perpendicular to the axial direction or one between them Heading directions.

Preferably are the perimeter of the conclusion and the perimeter of the recording room concentric.

Of the magnetic return and / or the receiving space for recording of the ring magnet can preferably be cylindrical be formed and in particular the shape of vertical circular cylinder exhibit. The ring magnet according to the invention is preferably shaped accordingly.

In a development of the invention is the resulting magnetic Induction under displacement along the second circumferential line by one length, which two return segments corresponds, asymmetrically. In particular, the shift can be longitudinal the circumferential line of the receiving space by a length corresponding to the Angular range of two return segments corresponds to asymmetrical be.

In another embodiment of the present invention have all return segments along the corresponding Circumference equal length.

In a preferred embodiment is the resulting magnetic induction with displacement along the circumferential line the receiving space by half a circumference symmetrical. Especially can the magnetic induction under the shift by half Circumference in a magnetic induction pass, which complete or with the magnetic induction before the shift almost completely (as described above). As stated above, this can be during operation compensate for the reluctance occurring torques of the ring magnet delocal.

As described above, are also induction curves, which point symmetric to the center of the recording space or symmetrical Reflected on a plane through the center of the recording room are advantageous for the compensation of the reluctance torques.

alternative is an over the circumference changed width of the Air gap between the magnetizing and the magnetizing Magnetic material and / or between the magnetic material and the conclusion possible.

The The invention also relates to a magnetizing system for the magnetization of ring magnets with a Magnetisierspule with Magnetizing wires, which are connectable to a power source, and a receiving space for receiving a to be magnetized Ring magnet. The shape and / or the arrangement and / or the composition the magnetizing coil and / or the Magnetisierdrähte are set up in the receiving space a resulting magnetic Induction to produce, which along a circumferential line of the receiving space has an asymmetry when the magnetizing coil is traversed by an electric current.

Of the the aforementioned embodiment is based on the knowledge that that is a ring magnet with asymmetric magnetization and the resulting beneficial effects also under Use of a magnetizing system without magnetic return can be prepared by the magnetizing coil or the Magnetisierdrähte in suitable form and / or composition are arranged.

In a preferred embodiment, vari The distance of the magnetizing wires from the receiving space. The variation of the distance between the magnetizing wires and the space receiving the ring magnet leads to a corresponding variation of the magnetization along its circumferential line. By asymmetrically varying the distance along the outer diameter of the coil, the ring magnet can be given a corresponding asymmetrical magnetization with the advantages described above.

In Another preferred embodiment comprises Magnetizing according to the invention a first Group of magnetizing wires extending from the magnetizing wires a second group in their electrical conductivity differ.

In a development of the invention comprises the magnetizer Magnetizing wires of different diameters and / or different shape. Additionally or alternatively Also, the arrangement and shape of the poles of the magnetizing coil vary.

By Variation of the electrical conductivity or the diameter or the geometry of the magnetizing wires with the Magnetisieranlage invention Along the circumferential line also an asymmetrical induction course produce.

The described characteristics of Magnetisieranlage, both individually or in combination.

The The invention further includes a method for magnetizing ring magnets with the following steps: Provision of a ring magnet to be magnetized along a ring-shaped circumferential line; Create a magnetic induction at the location of the ring magnet such that the magnetic Induction along the circumferential line has an asymmetry; and generating pole regions of predetermined magnetization the circumference.

As stated above, allows the formation of an asymmetric Course of the magnetic induction along the circumferential line an effective reduction of reluctance moments, so that the Grooving is reduced.

In A preferred embodiment is the magnetic induction under displacement along the circumferential line around the length two pole areas asymmetrical.

In Another preferred embodiment is the magnetic Induction symmetrical under reflection at a plane, which is a Axial direction of the ring magnet and the center of the ring magnet contains.

In a development of the method according to the invention Magnetic induction is symmetric under displacement along the circumferential line by half or third circumference.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The Features and numerous advantages of the present invention The best way to understand this is to read a detailed description of the attached Understand figures in which:

1a schematically shows the course of the magnetization along a circumferential line of a ring magnet which has been magnetized in a Magnetisieranlage with a conventional magnetizing coil shows;

1b a corresponding magnetization curve of a ring magnet which has been magnetized using a Magnetisieranlage with a magnetic yoke shows;

2a schematically shows a formed with copper deposits magnetic yoke for a magnetizing system;

2 B schematically shows another magnetic yoke, which is provided along a circumferential line with recesses shows;

3a shows a ring magnet according to the invention in unwound representation;

3b schematically the course of magnetization along a perimeter of the in 3a shown ring magnet shows;

4a a magnetizing system according to the invention in a schematic overview shows;

4b a perspective view of a Magnetisierspule the Magnetisieranlage invention;

5 a magnetic conclusion of the magnetization of the invention 4a in a developed schematic representation;

6a shows a section of a yoke according to the invention with honeycomb yoke segments; and

6b an alternative inference according to the invention according to another embodiment of the invention shows.

The in the 1a and 1b shown Magnetization characteristics typically resulting from the use of a conventional magnetizing coil or magnetizing coil have been explained in detail above with respect to the prior art, as well as those in FIGS 2a and 2 B shown, magnetic conclusions, which represent the starting point of the invention.

3a shows a cylindrical ring magnet according to the invention 44 in unwound representation with 12 pole regions 32/1 to 32/12 along the perimeter 30 , The Polbereiche have the same length, with north poles with N and south poles with S and the asymmetric magnetization is indicated as hatching. The in 3a shown ring magnet 44 is a circular ring with constant diameter and constant height. However, the invention is not limited to a ring magnet of this shape and relative dimensions, but transferable to a variety of different magnets in different shapes and made of different materials.

3b shows the in 3a As a hatching indicated course of the magnetization M along the circumference 30 in a diagram. In correspondence to 3a shows 3b along the perimeter 30 three different magnetization curves: a trapezoidal course with a broad saturation plateau and a flattened transition at the pole boundary 14 for the pole areas 32/1 and 32/2 , a steep magnetization curve with a slightly flattened transition at the pole boundary 14 for the subsequent pole areas 32/3 and 32/4 and a saturation region with a steeper transition at the pole boundaries for the pole regions which is less broad than the first curve 32/5 and 32/6 , The magnetization takes place in all pole areas in each case to saturation. All pole areas each have identical length d / 2. This sequence of the magnetization curve becomes in the following pole regions 32/7 to 32/12 repeated, wherein the end point B coincides with the starting point A.

In the embodiment shown, the 12 Divide Polbereiche so in three groups of different magnetization, the first group, the Polbereiche 32/1 and 32/2 such as 32/7 and 32/8 , the second group the pole areas 32/3 and 32/4 such as 32/9 and 32/10 and the third group the pole areas 32/5 and 32/6 such as 32/11 and 32/12 and the groups comprise each other along the circumferential direction 30 alternate cyclically. The departure from the previously known from the prior art symmetric magnetization curve, as exemplified in the 1a and 1b is shown, leads to an effective compensation of disturbing reluctance torques and therefore to a jerk-free, smooth running during operation of the electrical machine.

Of the shown asymmetric magnetization course leads in Operation of the electric machine also causes the acoustic Emission spectrum has a less pronounced peak, but over a further frequency range is distributed. The so-called pure tone ratio (pure tone ratio), which is the ratio of the maximum frequency range Indicates emission (center frequency) to the sidebands is lowered, so that when operating the electric machine resulting noise compared to machines with previously known Ring magnets of highly symmetric magnetization as less loud and be distracting.

As stated above, is in the 3a and 3b shown magnetization course under displacement along the circumferential direction 30 Symmetrical by half a circumference, so goes under displacement by a distance 3d along the direction x in a magnetization, which corresponds to the original magnetization substantially, ie as described above in the context of manufacturing tolerances. Schematically, such a magnetization can be characterized by the letter sequence abcabc, where a stands for the magnetization of the first group, b for the magnetization of the second group and c for the magnetization of the third group. As stated in the introduction, this ensures that the reluctance torques occurring during operation of the ring magnet are delocal compensated along the circumferential direction and cancel each other out.

A similarly effective compensation of the reluctance occurring moments can be except in the 3a and 3b for example, in a configuration in which the resulting magnetization is symmetrical with reflection at a plane containing an axial direction of the ring magnet and the center of the ring magnet. An example of such a configuration is the sequence abaaba, where a again stands for a first magnetization of two first pole regions and b for a second magnetization of two subsequent pole regions. Although the latter configuration, in contrast to the previous example, is not symmetrical with displacement along the circumferential direction by half the circumference, it nevertheless has a point symmetry with reflection at the center of the ring magnet, which also causes a delocal compensation of the reluctance torques that occur.

The The above exemplary configurations are merely illustrative The illustration of the invention and should not be limited.

4a shows schematically and exemplarily the structure of a magnetizing system according to the present invention for producing a ring magnet having the above-described asymmetric magnetization.

The magnetizing system shown comprises a magnetizing coil 18 with cylindrical structure, wherein the cylinder axis Z perpendicular to the plane of the 4a runs. The magnetizing coil 18 is connectable to a power source (not shown). The illustrated magnetization system further comprises an annular magnetic yoke 20 , which is the magnetizing coil 18 concentrically surrounds, and a likewise annular receiving space 22 for receiving a ring magnet to be magnetized between the magnetizing coil 18 and the magnetic inference 20 , In the presentation of the 4a is the recording room 22 shown without ring magnet. The recording room 22 Also contains fixing elements for fixing a ring magnet during the magnetization, in the representation of 4a are also not shown for clarity.

The magnetic inference 20 is along a first circumferential line 24 , which the magnetic conclusion 20 once completely traversed in the drawing plane and therefore forms a closed circular line, in several return segments 1.26 to 26/12 divided. In the illustration shown are 12 Return segments are shown, which have identical lengths and depths and thus cover the same angular ranges. In addition, all return segments 1.26 to 26/12 transverse to the circumferential direction on a constant width b.

The present invention is not based on the in 4a illustrated magnetic return 20 but includes a wide variety in their number, shape, composition and size of varying conclusion segments 26 , In particular, the magnetic inference 20 into any number of inference segments 26 be divided, which include different sizes, shapes and materials. Also, the width b of the return segments 26 transverse to the first circumferential line 24 vary. Alternative magnetic conclusions 20 will be referred to below with reference to 6a and 6b described.

The in 4a shown magnetic inference 20 includes several deposits 1.28 to 12.28 , each with a return segment 26 / n a deposit 28 / n with n = 1, ..., 12 has. In the conclusion shown 20 are the inference segments 1.26 to 26/12 Made of non-magnetic steel, while the deposits 1.28 to 12.28 are formed of ferromagnetic steel. Alternatively, however, vice versa, the return segments 1.26 to 26/12 be formed of ferromagnetic steel, while the deposits 1.28 to 12.28 are formed of non-magnetic steel. Likewise, a part of the inserts of ferromagnetic steel and the other deposits may be formed of non-magnetic steel.

A perspective view of a magnetizing coil according to the invention 18 with a bobbin 46 and magnetizing wires 48 is in 4b shown. The magnetizing wires 48 For example, copper wires are each two or more bent magnetizing wires 48 in adjacent grooves of the bobbin 46 can be inserted.

Will the magnetizing coil 18 A current flows through it, producing it in cooperation with the magnetic inference 20 in the recording room 22 a resulting magnetic induction along a second circumferential line 30 of the recording room 22 has an asymmetry. In particular, the inventive design of the return segments 1.26 to 26/12 with differently shaped inserts 1.28 to 12.28 a deviation from the previously known from the prior art symmetrical trapezoidal gene field profile. In departure from the state of the art, the course of the magnetic induction resulting according to the invention is under displacement along the second circumferential line 30 by one stretch, the two return segments 1.26 respectively. 2.26 corresponds, no longer symmetrical. Under a distance which the angular range α of two return segments 1.26 and 2.26 corresponds, becomes a distance d along the second circumferential line 30 which, measured from the center P of the concentric yoke arrangement, covers the same angular range as the two adjacent return segments 1.26 and 2.26 ,

The shape and design of the insoles 1.28 to 12.28 is in more detail in the drawing of 5 shown, which is a section through the magnetic yoke 20 along the first perimeter 24 shows. A comparison of the representation of 5 with the picture of 3a who are using the in 5 shown deposits resulting magnetization of the ring magnet 44 shows that illustrates the shape and design of the deposits 1.26 to 26/12 directly in the magnetization of the corresponding pole regions 32/1 to 32/12 reflects. In the embodiment shown, two consecutive return segments 1.26 and 2.26 a first group of deposits 1.28 . 2.28 with halbellipsenförmigem cross-section on. The inference segments 3.26 and 4.26 a second group of return segments, on the other hand, have inserts with a triangular cross-section 3.28 . 4.28 on. The inference segments 5.26 and 6.26 a third Group of inference segments have deposits 5.28 . 6.28 with rectangular cross section. For the following six inference segments 7.26 to 26/12 the same sequence of deposits is repeated.

In the in 4a The arrangement shown is the second circumferential line 30 concentric with the first circumferential line 24 and divides the annular receiving space 22 center. However, the relevant in the context of the invention asymmetry of the generated magnetic induction can also along other circumferential lines in the receiving space 22 be measured, ie in particular along circumferential lines, which closer to the magnetic yoke 20 or further away from him.

6a shows an alternative magnetic inference 20 in schematic section. Unlike in the 4a and 5 illustrated magnetic return 20 has the in 6a shown magnetic return neither a constant width transverse to the first circumferential line 24 still deposits 28 on. Rather, the shows in 6a illustrated conclusion a honeycomb-like shape, wherein each return segment of a honeycomb 42 equivalent. With suitable dimensioning, this inference 20 affect the magnetization of the ring magnet similarly as the conclusion with the deposits described.

Another alternative magnetic inference 20 , which has recesses along its circumferential direction is shown in schematic section in FIG 6b illustrated. Unlike the in 6a shown honeycomb has the inference 20 of the 6b a sequence of differently shaped segments of rectangular, circular and diamond-shaped cross section. As above the example of the 5 also explained in this case, the shape of the return segments in the magnetization of a ring magnet magnetized with such a conclusion.

As stated above, however, an asymmetric magnetization curve of the ring magnet can also be used in a magnetizing system without any conclusion 20 achieve. By modifying the magnetizing coil 18 In particular, the distance between the Magnetisierdrähte 48 from the recording room 22 vary, with an asymmetric variation along an outer circumference of the magnetizing coil 18 in turn, in a corresponding asymmetric magnetization of the ring magnet 44 reflects. Likewise, the asymmetry of the magnetization can be achieved by varying the geometry and the material of the magnetizing wires 48 Taxes. In particular, along an outer peripheral line of the magnetizing coil 18 Magnetisierdrähte 48 variable diameter used to be in the receiving space 22 to generate an asymmetric field course. Likewise, in addition to magnetizing wires with a circular cross-section, it is also possible to use flat-tube wires.

In a further embodiment comprises the inventive Magnetizing system both a magnetic return as well as an asymmetrically shaped bobbin.

The The above-described embodiments and the illustrative Drawings are solely for the purpose of illustrating the invention Magnetizing and the invention Ring magnet and the method according to the invention for the magnetization of ring magnets and the invention in restrict no way. The scope of the invention gives alone from the following claims.

10 12

pole areas

14

pole boundary

16

pole gap

18

magnetizing

20

magnetic conclusion

22

accommodation space

24

first peripheral line

26 / 1-26 / 12

Inference segments

28 / 1-28 / 12

insoles

30

second circumferential line of the receiving space 22 ; circumferentially

32 / 1-32 / 12

Pole areas of the ring magnet 44

34

cylindrical return with inserts 36

36

Copper inserts of the cylindrical yoke 34

38

cylindrical return with recesses 40

40

Recesses of the cylindrical yoke 38

42

diamonds a magnetic yoke according to the invention

44

ring magnet

46

bobbins

48

Magnetisierdrähte

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - US 6232862 B1 [0003]
• - US 6519833 B2 [0003]
• US 4748535 [0003]
• - DE 19633209 A1 [0011, 0012, 0012, 0012]

Claims (30)

Ring magnet ( 44 ) with several along a circumferential direction ( 30 ) alternating pole regions ( 32/1 - 32/12 ), wherein a magnetization of the pole regions ( 32/1 - 32/12 ) along the circumferential direction ( 30 ) has an asymmetry. Ring magnet ( 44 ) according to claim 1, in which the magnetization is displaced along the circumferential direction ( 30 ) by the length (d) of two pole regions ( 32/1 . 32/2 ) is asymmetric. Ring magnet ( 44 ) according to claim 1 or 2, wherein a magnetization in a first group of pole regions, which M mutually adjacent pole regions ( 32/1 . 32/2 ), of a magnetization in a second group of pole regions, which N subsequent, adjacent pole regions ( 32/3 . 32/4 ), where M and N are positive integers, preferably 2. Ring magnet ( 44 ) according to claim 3, wherein a magnetization in a third group of pole regions, which P of the second group subsequent, adjacent pole regions ( 32/5 . 32/6 ) differs from the magnetization of both the first group and the second group, where P is a positive integer, preferably 2. Ring magnet ( 44 ) according to one of claims 1 to 4, having a plurality of groups of a plurality of successive pole regions ( 32/1 - 32/12 ), wherein each of the groups has a different magnetization and the groups are arranged along the circumferential direction ( 30 ) alternate cyclically. Ring magnet ( 44 ) according to claims 1 to 5, in which all pole regions ( 32/1 - 32/12 ) along the circumferential direction ( 30 ) have an equal length. Ring magnet ( 44 ) according to one of Claims 1 to 6, in which the magnetization is displaced along the circumferential direction ( 30 ) is symmetrical about a half or a third circumference. Ring magnet ( 44 ) according to one of claims 1 to 7, in which the magnetization of the pole regions ( 32/1 - 32/12 ) point-symmetrical with reflection at the center of the ring magnet ( 44 ). Ring magnet ( 44 ) according to one of claims 1 to 8, in which the magnetization of the pole regions ( 32/1 - 32/12 ) is symmetrical with reflection at a plane which an axial direction of the ring magnet ( 44 ) and the center of the ring magnet ( 44 ) contains. Magnetizing system for the magnetization of ring magnets ( 44 ) comprising: a magnetizing coil ( 18 ) with magnetizing wires ( 48 ), which are connectable to a power source; a magnetic inference ( 20 ), which along a circumferential line ( 24 ) of the magnetic inference ( 20 ) into several return segments ( 1.26 - 26/12 ) is divided; and a recording room ( 22 ) for receiving a magnetizable ring magnet ( 44 ) between the magnetizing coil ( 18 ) and the magnetic inference ( 20 ); wherein the shape and / or the composition and / or the magnetic properties of the return segments ( 1.26 - 26/12 ) are arranged in the receiving room ( 22 ) to produce a resulting magnetic induction along a circumferential line ( 30 ) of the recording room ( 22 ) has an asymmetry when the magnetizing coil ( 18 ) is traversed by an electric current. Magnetizing system according to claim 10, wherein the return segments ( 1.26 - 26/12 ) Comprise aluminum, copper or non-magnetic steel. Magnetizing system according to claim 10, wherein the return segments ( 1.26 - 26/12 ) Iron or ferromagnetic steel. Magnetizing system according to claim 10 or 11, wherein at least some of the return segments ( 1.26 - 26/12 ) ferromagnetic inserts ( 1.28 - 12.28 ). Magnetizing system according to claim 10 or 12, wherein at least some of the return segments ( 1.26 - 26/12 ) non-magnetic deposits ( 1.28 - 12.28 ). Magnetizing system according to claim 13 or 14, wherein the inserts ( 1.28 - 12.28 ) have a trapezoidal cross-section or a diamond-shaped cross-section. Magnetizing system according to one of claims 10 to 15, wherein two adjacent return segments ( 1.26 - 26/12 ) differently shaped inserts ( 1.28 - 12.28 ). Magnetizing system according to one of claims 10 to 16, wherein the width of the return segments ( 1.26 - 26/12 ) in a direction transverse to the first circumferential line ( 24 ) varies. Magnetizing system according to claim 17, wherein the return segments ( 1.26 - 26/12 ) have a trapezoidal or diamond-shaped cross-section. Magnetizing system according to Ansprü 10 to 18, with the inference segments ( 1.26 - 26/12 ) Have recesses. The magnetizing apparatus according to claim 19, wherein a cross-sectional area of the recesses is along a direction perpendicular to the first circumferential line (FIG. 24 ) varies. Magnetizing system according to one of claims 10 to 20, wherein the resulting magnetic induction with displacement along the circumferential line ( 30 ) of the recording room ( 22 ) by a length (d), which two return segments ( 1.26 . 2.26 ), is asymmetric. Magnetizing system according to one of claims 10 to 21, wherein the resulting magnetic induction with displacement along the peripheral line ( 30 ) of the receiving space is symmetrical about a half or third circumference. Magnetizing system for the magnetization of ring magnets ( 44 ) comprising: a magnetizing coil ( 18 ) with magnetizing wires ( 48 ), which are connectable to a power source; and a recording room ( 22 ) for receiving a magnetizable ring magnet ( 44 ); the shape and / or the arrangement and / or the composition of the magnetizing coil ( 18 ) and / or the magnetizing wires ( 48 ) are arranged in the receiving room ( 22 ) to produce a resulting magnetic induction along a circumferential line ( 30 ) of the recording room ( 22 ) has an asymmetry when the magnetizing coil ( 18 ) is traversed by an electric current. Magnetizing system according to one of Claims 10 to 23, in which the spacing of the magnetizing wires ( 48 ) from the recording room ( 22 ) varies. Magnetizing system according to one of the claims 10 to 24 with a first group of magnetizing wires, which differ from the magnetizing wires of a second group differ in their electrical conductivity. Magnetizing system according to one of claims 10 to 25 with magnetizing wires ( 48 ) of different diameter and / or different shape. Method for magnetizing ring magnets ( 44 ) comprising the following steps: providing a ring magnet to be magnetized ( 44 ) along an annular peripheral line ( 30 ); Generating a magnetic induction at the location of the ring magnet ( 44 ) such that the magnetic induction along the circumferential line ( 30 ) has an asymmetry; and generating pole regions ( 32/1 - 32/12 ) predetermined magnetization along the circumferential line ( 30 ). Method according to Claim 27, in which the magnetic induction is shifted along the circumferential line ( 30 ) is asymmetric by a length of two pole regions. A method according to claim 27 or 28, wherein the magnetic induction along the peripheral line ( 30 ) is symmetrical with reflection at a plane which an axial direction of the ring magnet ( 44 ) and the center of the ring magnet ( 44 ) contains. Method according to one of claims 27 to 29, wherein the magnetic induction is symmetrical with displacement along the peripheral line ( 30 ) is half a third of the circumference.