ELECTROMAGNETIC ROTATING DRIVE AND ROTATIONAL DEVICE

Description

[0001] The invention relates to an electromagnetic rotary drive and a rotation device according to the preamble of the independent patent claim of the respective category.

[0002] Electromagnetic rotary drives are known that are designed and operated according to the principle of the bearingless motor. The term "bearingless motor" refers to an electromagnetic rotary drive in which the rotor is fully magnetically mounted relative to the stator, without the need for separate magnetic bearings. The stator is designed as both a bearing and drive stator, serving as the stator for the electrical drive and the stator for the magnetic mounting. The electrical windings of the stator generate a rotating magnetic field that exerts a torque on the rotor, causing it to rotate, and also exerts an adjustable lateral force on the rotor, allowing its radial position to be actively controlled. Thus, three degrees of freedom of the rotor are actively controllable: its rotation and its radial position (two degrees of freedom).With regard to three further degrees of freedom—namely its position in the axial direction and tilting relative to the radial plane perpendicular to the desired axis of rotation (two degrees of freedom)—the rotor is passively magnetically supported and stabilized by reluctance forces, meaning it cannot be controlled. The absence of a separate magnetic bearing, combined with the complete magnetic support of the rotor, is the characteristic that gives the bearingless motor its name.

[0003] The bearingless motor is now well known to experts and is used in numerous different applications. Basic descriptions can be found, for example, in EP A 0 860 046 and EP-A-0 819 330.

[0004] In Fig. 1 A perspective drawing, illustrative in nature, shows a possible design of a bearingless motor, which is known from the state of the art. For better understanding, it shows Fig. 2 Another perspective sectional view of the bearingless motor from Fig. 1 , where the cut is made in the axial direction A'. To indicate that the representation is in Fig. 1 und Fig. 2 Since this is a prior art device, the reference numerals are indicated by an apostrophe or a dash. The bearingless motor is collectively designated by the reference numeral 1' and is designed here as an external rotor. This means that the stator 2' is arranged radially inside and is surrounded by the rotor 3'.

[0005] The stator 2' comprises a plurality – here six – distinct stator poles 21', each extending radially outwards from an annular backplate 22'. A radial direction is defined as a direction perpendicular to the axial direction A', which is defined by the nominal axis of rotation of the rotor 3', i.e., the axis of rotation around which the rotor 3' rotates in the operating state when it is in a centered and untilted position relative to the stator 2'. The backplate 22' and the stator poles 21' are made of a ferromagnetic material, for example, iron.

[0006] In Fig. 1 und Fig. 2 Only the magnetically active core 31' of the rotor 3' is shown, which is ring-shaped and permanent magnet. The magnetically active core 31' comprises a plurality of permanent magnets 311', each configured as a ring segment, with the entirety of the permanent magnets 311' forming a ring. Each permanent magnet 311' is magnetized radially, with adjacent permanent magnets 311' being magnetized in opposite directions, so that, viewed circumferentially, the permanent magnets 311' are alternately magnetized radially inwards and radially outwards. The magnetization of each individual permanent magnet 311' is indicated by an arrow without a reference symbol within the permanent magnet 311'.

[0007] The magnetically effective core 31' also has a return ring 312' made of a ferromagnetic material, for example iron, which surrounds the permanent magnets 311' and serves to guide the magnetic flux.

[0008] To generate the electromagnetic rotating fields necessary for the magnetic drive and magnetic bearing of the rotor 3', the stator poles 21' carry windings. In the Fig. 1 und Fig. 2 In the illustrated embodiment, the windings are designed, for example, such that a discrete coil 61' is wound around each stator pole 21'. These coils 61' generate, during operation, the rotating electromagnetic fields that produce a torque on the rotor 3' and that exert an arbitrarily adjustable lateral force in the radial direction on the rotor 3', so that the radial position of the rotor 3', i.e., its position in the radial plane perpendicular to the axial direction A', can be actively controlled or regulated.

[0009] With regard to three further degrees of freedom, namely the position of the rotor 3' in axial direction A' and tilting (two degrees of freedom), the rotor 3' is passively magnetically supported, i.e. not controllable, by reluctance forces or stabilized.

[0010] With regard to the passive magnetic bearing of the rotor 3', it is preferred that the inner diameter of the magnetically effective core 31' of the rotor 3' is dimensioned such that it is at least 2.6 times the height h' of the magnetically effective core 31' in the axial direction A'. Fig. 2 Here, R' denotes the inner radius of the annular magnetically active core 31' of the rotor 3'. The condition 2 * R' ≥ 2.6 * h' should therefore be satisfied, meaning that the inner diameter of the magnetically active core 31' should be larger than, or at least as large as, 2.6 times its height h' in the axial direction A'.

[0011] Electromagnetic rotary drives designed according to the principle of the bearingless motor have proven their worth in a wide variety of applications.

[0012] Due to the absence of mechanical bearings, the bearingless motor 1' is particularly suitable for pumping, mixing, or stirring devices that convey highly sensitive substances, such as blood pumps, or where very high purity requirements apply, for example, in the pharmaceutical or biotechnology industries, or that convey abrasive or aggressive substances that would very quickly destroy mechanical bearings, such as pumps or slurry mixers in the semiconductor industry. Bearingless motors are also used in semiconductor manufacturing to carry and rotate wafers, for example, when they are coated or treated with photoresist or other substances.

[0013] A further advantage of the bearingless motor principle arises from the design of the rotor as an integral rotor, which serves as the rotor for the electromagnetic drive, as well as for the pump, agitator, mixer, or wafer rotating holder. In addition to the contactless magnetic bearings, this design offers the advantage of a very compact and space-saving form factor.

[0014] Furthermore, the bearingless motor principle allows for designs where the rotor 3' can be easily separated from the stator 2'. This is a significant advantage because, for example, the rotor 3' can be designed as a single-use component. Such single-use applications frequently replace processes where, previously, due to very high purity requirements, all components that come into contact with the substances being treated had to be laboriously cleaned and sterilized, for example, by steam sterilization. In the single-use design, the components that come into contact with the substances being treated are used only once and then replaced by new, i.e., unused, single-use parts for the next application.

[0015] Examples include the pharmaceutical and biotechnology industries. These sectors frequently produce solutions and suspensions that require careful mixing or conveying of substances.

[0016] In the pharmaceutical industry, for example, the highest purity standards must be met in the production of pharmaceutically active substances; often, the components that come into contact with these substances must even be sterile. Similar requirements arise in biotechnology, for example, in the production, treatment, or cultivation of biological substances, cells, or microorganisms, where an extremely high degree of purity must be guaranteed to ensure the usability of the manufactured product. Bioreactors, in which biological substitutes for tissues or specific cells, or other highly sensitive substances, are cultivated, serve as another example. Here, too, pumps, stirrers, or mixing devices are needed to ensure, for example, the continuous mixing of the nutrient solution or its continuous circulation within the mixing vessel.A very high level of purity must be ensured in order to protect the substances or the products manufactured from contamination.

[0017] In such applications, the pumping, stirring, or mixing device consists of a single-use component and a reusable component. The single-use component comprises those parts that come into contact with the substances and are designed as single-use parts. This includes, for example, the pumping or mixing vessel with the rotor 3' provided therein, which then includes, for example, a paddle wheel for conveying the substances. The reusable component comprises those parts that are used continuously, i.e., multiple times, such as the stator 2'. Such a device is disclosed, for example, in EP-B-2 065 085.

[0018] In all these applications where the bearingless motor is successfully used, it is in principle possible to use the bearingless motor as an internal rotor, i.e. with an internal rotor and a stator arranged around it, or as an external rotor (see Fig. 1 ), that is, to be designed with an internal stator 2' and a rotor 3' arranged around it. However, particularly in external rotor configurations, it has been shown that for some applications the passive magnetic stabilization of the rotor 3', especially against tilting, reaches its limits or is even insufficient to guarantee safe and trouble-free operation of the rotary drive. Compared to the internal rotor, the maximum achievable tilt-stabilizing torque is drastically lower in the external rotor. This significantly reduced passive magnetic stabilization against tilting in the external rotor configuration is insufficient in practice for some applications.

[0019] US 5,686,772 discloses a magnetic bearing and an arrangement comprising a stator and a rotor mounted in such a bearing. The rotor is passively magnetically mounted in a radial plane and actively magnetically mounted in the axial direction.

[0020] US 2010 / 282528 discloses an electromechanical battery with a support element and a rotating frame that carries a battery. A rotating electrical connection between the support element and the battery is designed such that the battery can be charged and discharged while the rotating frame rotates.

[0021] J.-P. Yonnet: "Permanent magnetic bearings and couplings", IEEE TRANSACTIONS ON MAGNETICS, Vol. 17, No. 1, January 1, 198, pages 1169-1173 reveals the calculation of magnetic forces and stiffnesses based on the coupling energy between elementary dipoles.

[0022] US 2007 / 080595 discloses a superconducting contactless rotating device in which a rotating permanent magnet is used to rotate another permanent magnet without contact.

[0023] Based on this prior art, it is therefore an object of the invention to propose an electromagnetic rotary drive designed as an external rotor, comprising a magnetically contactless driven and magnetically contactless supported rotor, wherein the passive magnetic stabilization of the rotor is significantly improved, particularly with regard to tilting. Furthermore, it is an object of the invention to propose a rotary device comprising such a rotary drive.

[0024] The subject matter of the invention that solves this problem is characterized by the features of the independent patent claim of the respective category.

[0025] According to the invention, an electromagnetic rotary drive is proposed, designed as an external rotor, with a rotor comprising an annular, permanent-magnet, magnetically effective core arranged around a stator, and having a magnetic center plane, wherein the stator is designed as a bearing and drive stator, with which the rotor can be driven magnetically without contact about a desired axis of rotation in the operating state, which defines an axial direction, and with which the rotor can be magnetically supported without contact with respect to the stator, wherein the rotor is actively magnetically supported in a radial plane perpendicular to the axial direction, and is passively magnetically stabilized in the axial direction and against tilting, wherein the stator (2) comprises coils (61) with which a rotating magnetic field can be generated, which exerts a torque on the magnetically effective core (31) of the rotor (3),which causes its rotation, and which, on the other hand, exerts an arbitrarily adjustable transverse force on the magnetically effective core (31) of the rotor (3) so that its radial position - i.e., its position in the radial plane - is actively controllable or adjustable, and that the rotor comprises a magnetically effective bearing ring which is arranged radially outside and spaced apart from the magnetically effective core of the rotor, and wherein an additional bearing stator with a magnetically effective stator ring is provided for interaction with the bearing ring, wherein the additional bearing stator is designed and arranged such that the stator ring passively stabilizes the rotor magnetically against tilting,wherein the bearing ring is connected to the magnetically effective core of the rotor via a connecting element made of a low-permeable material, wherein both the bearing ring of the rotor and the stator ring of the additional bearing stator each comprise at least one permanent magnet, and wherein the additional bearing stator comprises a support body for supporting the stationary stator ring.

[0026] The interaction of the additional bearing stator, more precisely the magnetically effective stator ring of the additional bearing stator, with the magnetically effective bearing ring of the rotor, results in significantly improved stabilization of the rotor against tilting relative to the radial plane. The radial plane is the one in which the radial position of the rotor is actively controlled magnetically. The additional bearing stator and the bearing ring of the rotor essentially function as an additional passive magnetic axial bearing for the rotor, which significantly increases the rotor's tilting stiffness.The maximum torque causing rotor tilting, which can be compensated for by the inventive design, is considerably greater than in known electromagnetic rotary drives designed as external rotors with a magnetically levitated, disk- or ring-shaped magnetically active rotor core, for example by at least a factor of 20. This allows the inventive rotary drive to be used in applications for which known designs are of little or no use, because the passive forces for stabilizing the rotor against tilting are not sufficiently large in these known designs.

[0027] The rotary drive according to the invention advantageously combines the known advantages of the bearingless motor principle with an additional passive magnetic axial bearing or axial stabilization of the rotor. For this purpose, the rotor of the rotary drive according to the invention has two different magnetically active areas, which are magnetically decoupled from each other, at least substantially, by the connecting element made of a low-permeability material: The annular magnetically active core of the rotor interacts with the stator, designed as a bearing and drive stator, in a manner known per se according to the principle of the bearingless motor.The magnetically effective bearing ring of the rotor, which is arranged radially outside the magnetically effective core, interacts with the magnetically effective stator ring of the additional bearing stator, thereby creating an additional passive magnetic axial bearing of the rotor, which in particular significantly increases the tilting stiffness of the rotor.

[0028] Several basic variants are possible regarding the design of the additional passive magnetic axial bearing.

[0029] For example, it is possible to design the magnetically active bearing ring as a permanent magnet and the stator ring of the additional bearing stator as a ferromagnetic material. The bearing ring can consist entirely of a permanent magnetic material, i.e., it can be designed as a permanent magnetic ring, either as a single piece or composed of several permanent magnetic segments, or it can comprise one or more permanent magnets connected by ferromagnetic spacers. The stator ring can be designed as a ferromagnetic ring, for example, as a single piece or segmented ring, and in particular as an iron ring.

[0030] Another option is to design the magnetically active stator ring of the additional bearing stator as a permanent magnet and the rotor bearing ring as a ferromagnetic material. The stator ring can consist entirely of a permanent magnetic material, for example, as a single permanent magnet ring, either as a single piece or composed of several permanent magnet segments, or it can comprise one or more permanent magnets connected by ferromagnetic spacers. The bearing ring can be a ferromagnetic ring, for example, as a single piece or segmented ring, and in particular as an iron ring.

[0031] According to the invention, both the bearing ring of the rotor and the stator ring of the additional bearing stator each comprise at least one permanent magnet, i.e., are each designed as a permanent magnet. The stator ring and the bearing ring can each consist entirely of a permanent magnetic material, i.e., they can each be designed as a permanent magnetic ring, either in one piece or composed of several permanent magnetic segments, or they can each comprise one or more permanent magnets which are connected to each other, for example, by ferromagnetic spacers.

[0032] According to a preferred embodiment, the rotor bearing ring is arranged in the magnetic center plane of the rotor's magnetically active core. That is, the rotor bearing ring and the annular, magnetically active core of the rotor are arranged as concentric rings in the same plane, such that the bearing ring surrounds the magnetically active core centrally with respect to the axial direction.

[0033] In another, also preferred, embodiment, the bearing ring is arranged at a non-zero axial distance from the magnetic center plane of the rotor's magnetically active core, said distance being at most one-quarter, preferably at most one-fifth, of the inner radius of the bearing ring. In this embodiment, the annular magnetically active core of the rotor and the rotor's bearing ring are arranged parallel to each other and centered axially, such that their centers lie on the same axis, with the magnetically active core and the bearing ring being spaced axially apart. The bearing ring can be arranged above or below the magnetic center plane of the magnetically active core with respect to its normal operating position.Preferably, the distance of the bearing ring from the magnetic center plane is at most one quarter, and particularly preferably at most one fifth, of the inner radius of the bearing ring, so that the destabilizing effect of the additional axial support does not exceed the additional stabilization against tilting. The distance of the bearing ring from the magnetic center plane refers to the distance between the center plane of the bearing ring and the magnetic center plane in the axial direction.

[0034] There are several variants regarding the arrangement of the stator ring. According to a preferred variant, the stator ring of the additional bearing stator is arranged concentrically with the bearing ring of the rotor, such that the stator ring surrounds the bearing ring radially on the outside. That is, the bearing ring of the rotor and the stator ring of the additional bearing stator are arranged as concentric rings in the same plane, so that the stator ring surrounds the bearing ring centrally with respect to the axial direction.

[0035] According to another, equally preferred embodiment, the stator ring of the additional bearing stator is arranged axially spaced from the bearing ring of the rotor, the stator ring preferably having the same inner radius as the bearing ring. In this embodiment, the stator ring of the additional bearing stator and the bearing ring of the rotor are arranged parallel to each other and centered axially, so that their centers lie on the same axis, with the stator ring and the bearing ring being axially spaced apart. The stator ring can be arranged above or below the bearing ring with respect to the normal operating position, with the bearing ring and the stator ring being particularly preferably aligned axially.

[0036] Several variations are possible regarding the design of the connecting element that links the magnetically active core of the rotor to the rotor's bearing ring. For example, the connecting element can be designed as a complete ring disk positioned radially between the annular magnetically active core of the rotor and the rotor's bearing ring. Preferably, the connecting element is disk-shaped and optionally features a plurality of recesses to reduce the material required for the connecting element and its weight.

[0037] According to another, also preferred variant, the connecting element comprises a plurality of spokes, each of which extends in a radial direction between the magnetically effective core of the rotor and the magnetically effective bearing ring of the rotor.

[0038] With a view to achieving maximum additional stabilization and simplifying manufacturing, it is preferred that the stator ring and the bearing ring each consist of a permanent magnetic material and are each segmented with a plurality of permanent magnets. In this preferred embodiment, both the stator ring and the bearing ring are therefore made entirely of a permanent magnetic material. For manufacturing reasons, it is preferred that both the bearing ring and the stator ring are segmented, i.e., each stator ring and the bearing ring comprises a plurality of permanent magnets, each configured as a ring segment, with the entirety of the permanent magnets forming a complete ring.

[0039] There are several variations regarding the magnetization of the stator ring and the bearing ring.

[0040] According to a first preferred embodiment, the stator ring and the bearing ring are each magnetized in the axial direction, wherein the magnetization of the stator ring is directed opposite to the magnetization of the bearing ring.

[0041] According to another, also preferred, variant, the stator ring and the bearing ring are each magnetized in a radial direction, wherein the magnetization of the stator ring and the magnetization of the bearing ring are in the same direction, and wherein preferably the magnetization of the stator ring and the magnetization of the bearing ring are each directed radially outwards.

[0042] Another preferred variant consists in either the stator ring being magnetized in the axial direction and the bearing ring in the radial direction, or the stator ring being magnetized in the radial direction and the bearing ring in the axial direction.

[0043] The invention further proposes a rotary device for treating the surface of a disk-shaped body, in which the body is rotatable for treatment. This rotary device comprises an electromagnetic rotary drive configured according to the invention, wherein the rotor includes a holder for the disk-shaped body. The holder allows the body to be held on the rotor, or the body can be fixed to the rotor by means of the holder. Such a rotary device can be used, for example, in the semiconductor industry to apply fluids, e.g., suspensions, to the surfaces of substrates, such as the surface of wafers for the production of electronic components, in a controlled manner in order to treat their surfaces.Examples include chemical-mechanical polishing (CMP) processes using slurry, wafer cleaning and / or etching, photoresist application, and photoresist removal with solvents. In addition to these wet processes, where wafers are exposed to a fluid, the rotary device is also suitable for dry processes, particularly in the semiconductor industry. Examples of such dry processes, in which wafers or other components or substrates are rotated, include plasma etching, rapid thermal processing (RTP), atomic layer deposition (ALD), chemical vapor deposition (CVD), and physical vapor deposition (PVD).

[0044] In such wet or dry processes, the wafers, typically in the form of thin discs, are rapidly rotated in a process chamber and then exposed to the respective fluid (wet processes) or to radiation or the substances to be deposited (dry processes). For this purpose, the wafer to be treated can be attached to the rotor of the rotating device according to the invention using the holder and then rotated.

[0045] The invention further proposes a rotary device for conveying, mixing, or stirring fluids, wherein the rotary device comprises an electromagnetic rotary drive configured according to the invention, and wherein the rotor of the rotary drive is configured as the rotor of the rotary device. This embodiment, also referred to as an integral rotor, enables a particularly compact design of the rotary machine because the rotor of the electromagnetic rotary drive is simultaneously also the rotor of the rotary machine, with which a force is exerted on the fluid to be conveyed, mixed, or stirred.

[0046] According to one embodiment, the rotor has a plurality of vanes for mixing or stirring fluids, the vanes being arranged on the connecting element.

[0047] The rotary device according to the invention can also be configured to include single-use components. In such a configuration, the rotary device preferably has a single-use component and a reusable component, wherein the single-use component includes at least the rotor, which optionally has a plurality of vanes for conveying, pumping, mixing, or stirring fluids, and wherein the reusable component includes at least the stator and the additional bearing stator, with which the rotor can be magnetically driven and supported without contact during operation. If the rotary device is configured as a mixing or stirring device, the single-use components preferably also include, for example, the flexible mixing container in which the rotor is arranged.

[0048] Further advantageous measures and embodiments of the invention will be found in the dependent claims.

[0049] The invention will now be explained in more detail with reference to exemplary embodiments and the drawing. The partially schematic drawing shows (partially in section): Fig. 1: a perspective view of an electromagnetic rotary drive designed as a bearingless motor according to the prior art, Fig. 2: a perspective sectional view of the drive made of Fig. 1 Fig. 3: a perspective sectional view of a first embodiment of an electromagnetic rotary drive according to the invention, Fig. 4: a schematic section in the axial direction through the first embodiment made of Fig. 3 Fig. 5: a variant of the first embodiment in a perspective sectional view, Fig. 6: a schematic section in the axial direction through the variant made of Fig. 5 Fig. 7: a perspective sectional view of a second embodiment of an electromagnetic rotary drive according to the invention, Fig. 8: a schematic section in the axial direction through the second embodiment made of Fig. 7 Fig. 9: a variant of the second embodiment in a perspective sectional view, Fig. 10: a schematic section in the axial direction through the variant made of Fig. 9 , Fig. 11: a first variant for the design of the connecting element in a perspective view, Fig. 12: the first variant made of Fig. 11 in a perspective sectional view, Fig. 13: a second variant for the design of the connecting element in a perspective view, Fig. 14: the second variant from Fig. 13 in a perspective sectional view, Fig. 15: a variant for the design of the bearing ring and the stator ring in a perspective view, Fig. 16: the variant made of Fig. 15 In a perspective sectional view, Figs. 17-21: various variants for the magnetization of the bearing ring and the stator ring, each in a schematic sectional view, Fig. 22: a perspective view of an embodiment of a rotation device according to the invention, which is designed for treating a surface of a disk-shaped body, Fig. 23: a perspective sectional view of the embodiment made of Fig. 22 , Fig. 24: a schematic section in axial direction through the exemplary embodiment from Fig. 22 , Fig. 25: a perspective view of a variant of the embodiment from Fig. 22 , Fig. 26: a perspective sectional view of the variant from Fig. 24 , Fig. 27: a schematic section in axial direction through the variant made of Fig. 25 Fig. 28: a perspective view of an embodiment of a rotary device according to the invention for conveying, mixing or stirring fluids, Fig. 29: a perspective sectional view of the embodiment made of Fig. 28 , and Fig. 30: a schematic section in axial direction through the embodiment from Fig. 28 .

[0050] As already mentioned and explained, in Fig. 1 und Fig. 2 An electromagnetic rotary drive is shown, which is known from the prior art and which is designed as a bearingless motor.

[0051] Fig. 3 Figure 1 shows a perspective sectional view of a first embodiment of an electromagnetic rotary drive according to the invention, which is collectively designated by reference numeral 1. For better understanding, the figure is shown. Fig. 4 A schematic section in the axial direction through this first embodiment is shown. The rotary drive 1 is designed as an external rotor and comprises a stator 2 and a rotor 3 magnetically supported without contact with the stator 2. Furthermore, the rotor 3 can be magnetically driven to rotate about a target axis of rotation by means of the stator 2 without contact. The target axis of rotation is the axis about which the rotor 3 rotates in the operating state when the rotor 3 is in a centered and untilted position with respect to the stator 2. This target axis of rotation defines an axial direction A. Typically, the target axis of rotation defining the axial direction A coincides with the central axis of the stator 2.

[0052] In the following, a radial direction is defined as a direction that is perpendicular to the axial direction A.

[0053] The stator 2 comprises a plurality – here six – distinct stator poles 21, each extending radially outwards from a radially internal, annular return 22. To generate the rotating electromagnetic fields necessary for the magnetic drive and magnetic bearing of the rotor 3, the stator poles 21 carry windings. In the case of the Fig. 3 und Fig. 4 In the illustrated embodiment, the windings are designed, for example, such that a discrete coil 61 is wound around each stator pole 21. These coils 61 generate, during operation, the rotating electromagnetic fields that produce a torque on the rotor 3 and that exert an arbitrarily adjustable lateral force in the radial direction on the rotor 3, so that the radial position of the rotor 3, i.e., its position in the radial plane perpendicular to the axial direction A, can be actively controlled or regulated.

[0054] The rotor 3 comprises a magnetically active core 31, which is designed in the form of an annular disk or a circular cylindrical ring with height HR in the axial direction A and with inner radius IR. As is typical for an external rotor, the rotor 3, or rather its magnetically active core 31, is arranged around the stator 2, such that the stator 2 is radially inside the magnetically active core 31 of the rotor 3, and the stator poles 21 face the surrounding magnetically active core 31. The "magnetically active core 31" of the rotor 3 refers to that region of the rotor 3 which magnetically interacts with the stator poles 21 for torque generation and for generating the magnetic bearing forces.

[0055] At the In Fig. 3 und Fig. 4 In the first embodiment shown, the magnetically active core 31 of the rotor 3 is ring-shaped and permanent magnetized. The magnetically active core 31 comprises a plurality of permanent magnets 311, each configured as a ring segment, with the entirety of the permanent magnets 311 forming a ring. Each permanent magnet 311 is magnetized radially, with adjacent permanent magnets 311 being magnetized in opposite directions, so that, viewed circumferentially, the permanent magnets 311 are alternately magnetized radially inwards and radially outwards. The magnetization of each individual permanent magnet 311 is indicated by the arrow without a reference numeral within the respective permanent magnet 311.

[0056] Permanent magnets are generally defined as ferromagnetic or ferrimagnetic materials that are hard magnetic, i.e., exhibit a high coercive field strength. The coercive field strength is the magnetic field strength required to demagnetize a material. For the purposes of this application, a permanent magnet is defined as a material that has a coercive field strength, more precisely a coercive field strength of magnetic polarization, exceeding 10,000 A / m.

[0057] The magnetically effective core 31 also has a return ring 312 made of a ferromagnetic material, which radially surrounds the permanent magnets 311 and serves to guide the magnetic flux.

[0058] Both the annular return path 22 and the stator poles 21 of the stator 2, as well as the return path ring 312 of the magnetically active core 31 of the rotor 3, are each made of a soft magnetic material because they serve as flux guides for directing the magnetic flux. Suitable soft magnetic materials are, for example, ferromagnetic or ferrimagnetic materials, in particular iron, nickel-iron, or silicon-iron. In the case of the stator 2, a stator lamination stack configuration is particularly preferred, in which the stator poles 21 and the return path 22 are laminated, meaning they consist of several thin elements stacked together. The return path ring 312 of the magnetically active core 31 of the rotor 3 can also be laminated.

[0059] During operation of the rotary drive 1, the magnetically active core 31 of the rotor 3 interacts with the stator poles 21 of the stator 2 according to the bearingless motor principle described above, in which the rotor 3 can be driven magnetically without contact and can be magnetically supported without contact with respect to the stator 2. For this purpose, the stator 2 is designed as a bearing and drive stator, with which the rotor 3 can be driven magnetically around the desired axis of rotation without contact in the operating state – i.e., set into rotation – and can be magnetically supported without contact with respect to the stator 2.

[0060] The principle of the bearingless motor is now well known to those skilled in the art, so a detailed description of its function is no longer necessary. The principle of the bearingless motor means that the rotor 3 is fully magnetically supported, with the stator 2 designed as both a bearing and drive stator, serving as both the stator of the electric drive and the stator of the magnetic support. The stator 2 comprises windings, in this case the coils 61, which realize both the drive and bearing functions. The coils 61 generate a rotating magnetic field that, firstly, exerts a torque on the magnetically active core 31 of the rotor 3, causing its rotation, and secondly, exerts an adjustable lateral force on the magnetically active core 31 of the rotor 3, so that its radial position—that is, its position in the radial plane—can be actively controlled or regulated.In contrast to conventional magnetic bearings, the bearingless motor achieves its magnetic bearing and drive via rotating electromagnetic fields. These fields exert a torque and an adjustable lateral force on the magnetically active core 31 of the rotor 3. The required rotating fields can be generated either with different coils or by computationally superimposing the necessary currents and then using a single coil system, in this case, the coils 61. Therefore, in a bearingless motor, it is not possible to divide the electromagnetic flux generated by the coils 61 of the stator 2 into one flux solely for rotor drive and another solely for the magnetic bearing of the rotor.

[0061] According to the principle of the bearingless motor, at least three degrees of freedom of the rotor 3, namely its position in the radial plane and its rotation, are actively controllable. With respect to its axial deflection in the axial direction A, the magnetically active core 31 of the rotor 3 is passively magnetically stabilized, i.e., not controllable, by reluctance forces. With respect to the remaining two degrees of freedom, namely tilting with respect to the radial plane perpendicular to the desired axis of rotation, the magnetically active core 31 of the rotor 3 is also passively magnetically stabilized. Thus, the rotor 3 is passively magnetically supported or passively magnetically stabilized in the axial direction A and against tilting (a total of three degrees of freedom) by the interaction of the magnetically active core 31 with the stator poles 21, and actively magnetically supported in the radial plane (two degrees of freedom).

[0062] As is generally the case, in this application an active magnetic bearing refers to one that is actively controllable or adjustable, for example, via the rotating electromagnetic fields generated by the coils 61. A passive magnetic bearing or passive magnetic stabilization refers to one that is not controllable or adjustable. Passive magnetic bearing or stabilization is based, for example, on reluctance forces, which return the rotor 3 to its equilibrium position when it is deflected from its equilibrium position, i.e., when it is displaced axially or tilted.

[0063] Furthermore, the magnetic median plane C of the magnetically active core 31 of the rotor 3 is defined as the plane perpendicular to the axial direction A in which the magnetically active core 31 of the rotor 3 is mounted in the operating state when the rotor 3 is not tilted. Typically, for an annular magnetically active core 31, the magnetic median plane C is the geometric median plane of the magnetically active core 31 of the rotor 3, which lies perpendicular to the axial direction A. The plane in which the magnetically active core 31 of the rotor 3 is mounted in the stator 2 during operation is also referred to as the radial plane. The radial plane defines the xy-plane of a Cartesian coordinate system whose z-axis runs in the axial direction A. If the magnetically active core 31 of the rotor 3 is not tilted, the radial plane coincides with the magnetic median plane C.

[0064] The radial position of the magnetically effective core 31 or of the rotor 3 refers to the position of the rotor 3 in the radial plane.

[0065] A radial bearing or radial support refers to a bearing arrangement for the rotor 3 with which the radial position of the rotor 3 can be stabilized, i.e., a bearing arrangement which supports the rotor 3 in the radial plane and thus with respect to its radial position.

[0066] An axial bearing or axial stabilization refers to a bearing or stabilization of the rotor 3 that stabilizes its position with respect to the axial direction A and prevents tilting. Such tilting represents two degrees of freedom and describes deflections where the instantaneous axis of rotation of the rotor 3 no longer points exactly in the axial direction A, but forms a non-zero angle with the intended axis of rotation. In the case of tilting, the magnetic center plane C is therefore no longer in or parallel to the radial plane, but forms a non-zero angle with the radial plane.

[0067] As already mentioned, the magnetically active core 31 of the rotor 3 interacts with the stator poles 21 of the stator 2 according to the principle of a bearingless motor. This interaction drives the rotation of the rotor 3. Furthermore, this interaction provides active magnetic radial bearing support for the rotor 3, and the rotor 3 is passively magnetically stabilized against tilting.

[0068] With regard to the passive magnetic bearing of the rotor 3, it is preferred that the inner diameter of the magnetically effective core 31 of the rotor 3 is dimensioned such that it is at least 1.3 times the height HR of the magnetically effective core 31 in the axial direction A. Fig. 4 IR is the inner radius of the ring-shaped magnetically active core 31 of the rotor 3. The condition 2 * IR ≥ 1.3 * HR should therefore be satisfied, meaning that the inner diameter should be larger than or at least as large as 1.3 times the height HR.

[0069] Another advantageous measure with regard to the passive magnetic bearing of the rotor 3 is if the stator poles 21 are dimensioned such that the outer diameter SD ( Fig. 4 The outer diameter SD of the stator 2 is at least 2.6 times the height SH of the stator poles 21 in the axial direction A. The outer diameter SD of the stator 2 is determined by the radial extent of the stator poles 21. It is therefore advantageous if the condition SD ≥ 2.6 * SH is met, meaning that the outer diameter SD of the stator 2 should be larger than, or at least as large as, 2.6 times the height SH of the stator poles 21.

[0070] According to the representation in Fig. 3 and in Fig. 4 The height SH of the stator poles 21 is equal to the height HR of the magnetically effective core 31 of the rotor 3. While this is a possible configuration, it is by no means necessary. Embodiments are also possible in which the height SH of the stator poles 21 is smaller or larger than the height HR of the magnetically effective core 31 of the rotor 3.

[0071] The previously described design of the magnetically effective core 31 of the rotor 3 and the stator 2 is a preferred design, but is only to be understood as an example.

[0072] The magnetically active core 31 of the rotor can also have other forms of magnetization. Furthermore, the magnetically active core 31 can be designed entirely without permanent magnets that contribute to the drive torque or the generation of bearing forces. Thus, the magnetically active core 31 can also be purely ferromagnetic, for example, as a reluctance rotor.

[0073] There are also numerous known configurations of the stator 2. For example, the stator can contain one or more permanent magnets, or it can be designed as the stator of a temple motor with L-shaped stator poles. The long legs of the L extend axially in direction A, and the magnetically active core of the rotor is arranged around the short, radially outward-facing legs of the L. The coils are then arranged around these long legs, i.e., below the magnetic center plane of the magnetically active core of the rotor.

[0074] The regulation or control of an electromagnetic rotary drive, which is operated according to the principle of the bearingless motor, as well as the sensors required for this, e.g. position sensors and / or angle sensors, are sufficiently known to the person skilled in the art and therefore do not require further explanation here.

[0075] To significantly improve the passive magnetic stabilization of the rotor 3, particularly against tilting, an additional bearing stator 7 is provided according to the invention, which interacts with a magnetically effective bearing ring 34 of the rotor 3. This will be explained in more detail below with reference to the first embodiment.

[0076] The rotor 3 comprises the magnetically effective bearing ring 34, which is arranged radially outside and spaced apart from the magnetically effective core 31 of the rotor 3. The bearing ring 34 is designed as a permanent magnet ring with an inner radius LR, wherein the ring is magnetized in the axial direction A, as shown in the illustration ( Fig. 3 und Fig. 4 ) in axial direction A upwards. The magnetization of the bearing ring 34 is indicated by the arrows without reference numerals (in the bearing ring 34). The bearing ring 34 can be designed as a single-piece permanent magnet ring, or segmented, that is, composed of a plurality of ring-segment-shaped permanent magnets which together form the bearing ring 34 (see also Fig. 15 und Fig. 16 In the first embodiment, the bearing ring 34 is arranged in the magnetic center plane C of the magnetically active core 31 of the rotor 3; that is, the geometric center plane LM of the bearing ring 34, which extends perpendicular to the axial direction A, lies in the magnetic center plane C of the magnetically active core 31 of the rotor 3. The annular magnetically active core 31 and the bearing ring 34 are arranged concentrically, that is, they have a common center point. With respect to the axial direction A, the bearing ring 34 is arranged centered on the magnetically active core 31.

[0077] In the axial direction A, the bearing ring 34 has a height HL which is preferably smaller than the height HR of the magnetically effective core 31. However, embodiments are also possible in which the height HL of the bearing ring 34 is equal to or greater than the height HR of the magnetically effective core 31.

[0078] The bearing ring 34 and the magnetically active core 31 are connected to each other via an annular connecting element 35, which is arranged radially between the magnetically active core 31 and the bearing ring 34. The connecting element 35 extends radially from the return ring 312 of the magnetically active core 31 to the bearing ring 34. The connecting element 35 has an outer radius equal to the inner radius LR of the bearing ring 34.

[0079] The connecting element 35 is made of a low-permeability material, i.e., a material with low magnetic permeability (magnetic conductivity), so that the magnetically effective core 31 and the magnetically effective bearing ring 34 are magnetically decoupled from each other. This means that at least no significant magnetic flux can flow between the bearing ring 34 and the magnetically effective core 31 through the connecting element 35.

[0080] This low-permeability material can be, for example, a plastic, a paramagnetic metal (e.g., aluminum or stainless steel), a diamagnetic metal, or combinations of these materials. For the purposes of this application, low-permeability refers to materials whose permeability (relative permeability) deviates only slightly or not at all from 1 (the permeability of a vacuum). In any case, a low-permeability material has a permeability of less than 1.1. The low-permeability material from which the connecting element 35 is made forms flux barriers for the magnetic flux because it has a significantly lower magnetic conductivity than, for example, the ferromagnetic material from which the return ring 312 is made.

[0081] To decouple the magnetically active core 31 from the bearing ring 34 as effectively as possible, it is advantageous if the radial distance between the magnetically active core 31 and the bearing ring 34 is as large as possible. Advantageously, the bearing ring 34 is dimensioned such that its inner radius LR is at least 1.1 times, preferably at least 1.3 times, and particularly preferably at least 1.6 times the outer radius of the annular magnetically active core 31.

[0082] Since it is sufficient for understanding the invention, the drawing includes, for example, the following: Fig. 3 und Fig. 4 , of the rotor 3 only the magnetically active core 31, the connecting element 35 and the bearing ring 34 are shown. It is understood that the rotor 3 can of course also include further components such as casings or encapsulations, which are preferably made of a plastic, or vanes for mixing, stirring or pumping fluids (see e.g. Fig. 28 ), or supports for rotating bodies (see e.g. Fig. 23 ) or other components.

[0083] The additional bearing stator 7 comprises a magnetically active stator ring 71, which is designed and arranged to interact with the bearing ring 34 of the rotor 3. The stator ring 71 is stationary, meaning it does not rotate. In the first embodiment, the stator ring 71 is arranged radially outside and spaced apart from the bearing ring 34 of the rotor 3, such that it surrounds the bearing ring 34. The stator ring 71 is designed as a permanent magnet ring with an inner radius SR, wherein the ring 71 is magnetized in the axial direction A, as shown in the illustration ( Fig. 3 und Fig. 4 ) in axial direction A downwards. The magnetization of the stator ring 71 is indicated by the arrows without reference symbols (in the stator ring 71). The bearing ring 34 and the stator ring 71 are therefore each magnetized in axial direction A, with the magnetization of the stator ring 71 being directed opposite to the magnetization of the bearing ring 34.

[0084] The stator ring 71 can be designed as a single permanent magnet ring, or segmented, that is, composed of a plurality of ring-segment-shaped permanent magnets which together form the stator ring 71 (see also Fig. 15 und Fig. 16 In the first embodiment, the stator ring 71 is arranged in the magnetic center plane C of the magnetically active core 31 of the rotor 3; that is, the geometric center plane SM of the stator ring 71, which extends perpendicular to the axial direction A, lies in the magnetic center plane C of the magnetically active core 31 of the rotor 3. The bearing ring 34 and the stator ring 71 are arranged concentrically, that is, they have a common center point. With respect to the axial direction A, the stator ring 71 is centered on the bearing ring 34.

[0085] In the first embodiment, the ring-shaped magnetically effective core 31, the bearing ring 34 and the stator ring 71 are arranged concentrically in the magnetic rotor plane C, wherein the inner radius IR of the magnetically effective core 31 is smaller than the inner radius LR of the bearing ring 34 and the inner radius LR of the bearing ring 34 is smaller than the inner radius SR of the stator ring .

[0086] The inner radius SR of the stator ring 71 is dimensioned such that the stator ring 71 surrounds the bearing ring 34 with minimal clearance, thus minimizing the magnetic air gap between the bearing ring 34 and the stator ring 71 in the radial direction. On the one hand, the bearing ring 34 should be able to rotate freely within the stator ring 71; on the other hand, the magnetic resistance caused by the gap between the bearing ring 34 and the stator ring 71 should be as low as possible to enable efficient magnetic flux flow between the bearing ring 34 and the stator ring 71. The width of the gap between the bearing ring 34 and the stator ring 71 in the radial direction is at most a few millimeters, or even just one millimeter or less.

[0087] In the axial direction A, the stator ring 71 has a height HS that is preferably equal to the height HL of the bearing ring 34. However, embodiments are also possible in which the height HS of the stator ring 71 is smaller or larger than the height HL of the bearing ring 34.

[0088] Preferably, but not necessarily, the magnetically effective core 31, the bearing ring 34 and the stator ring 71 each have a rectangular cross-sectional area perpendicular to their respective circumferential direction.

[0089] The additional bearing stator 7 further comprises a support body 72 for supporting the stationary stator ring 71. The support body 72 forms a mechanically stable connection between the stator 2 and the magnetically effective stator ring 71 of the additional bearing stator 7.

[0090] The support body 72 comprises a disk-shaped radial part 721, which extends radially outwards from the stator 2, and an annular axial part 722, which extends axially from the radially outer edge of the radial part 721 in the direction A as shown ( Fig. 3 und Fig. 4 ) extends upwards. The stator ring 71 is attached to the axial part 722. At its radially inner edge, the disk-shaped radial part 721 has an annular connecting piece 723, with which the support body 72 is fixed to the stator 2. For this purpose, the connecting piece 723 can be attached, for example, to the annular return 22 of the stator 2, or also to a stator housing of the stator 2 (not shown).

[0091] How this Fig. 3 und Fig. 4 As shown, the support body 72 extends radially outwards below the coils 61 to beyond the bearing ring 34 of the rotor 3 and then axially upwards, so that the stator ring 71, fixed to the support body 72, is opposite or surrounds the bearing ring 34. The stator ring 71 is connected to the stator 2 and fixed relative to the stator 2 by the support body 72. Preferably, the support body 72 is formed in one piece, that is, the connecting piece 723, the radial part 721, and the axial part 722 are formed as a single structural unit.

[0092] To magnetically decouple the stator ring 71 from the stator 2 and, in particular, from the return 22 and the stator poles 21, the support body 72 – in the same manner as explained for the connecting element 35 – consists of a low-permeability material, i.e., a material that exhibits only low magnetic permeability (magnetic conductivity). The low-permeability material can be, for example, a plastic, a paramagnetic metal (e.g., aluminum or stainless steel), a diamagnetic metal, or combinations of these materials.

[0093] In the operating state of the electromagnetic rotary drive 1, the interaction of the bearing ring 34 and the stator ring 71 provides additional passive magnetic axial support and / or additional passive magnetic axial stabilization of the rotor 3. This significantly increases the stabilization of the rotor 3 against tilting, for example, by a factor of at least twenty. This increase, particularly in tilting stiffness, means that the entire passive magnetic axial support of the rotor 3 can absorb or compensate for tilting-inducing torques that are at least twenty times greater than those of comparable embodiments without the bearing ring 34 and the stator ring 71.It is particularly advantageous that the influence of the additional magnetic axial bearing (bearing ring 34 and stator ring 71) on the radial bearing of the rotor 3 can be compensated by the active radial bearing, which is realized by the interaction of the magnetically effective core 31 of the rotor 3 with the stator poles 21.

[0094] The electromagnetic rotary drive 1 thus comprises two magnetic circuits which are separated or magnetically decoupled from each other by the low-permeable connecting element 35 and the low-permeable support body 72: The magnetically effective core 31 interacts magnetically with the stator poles 21 according to the principle of the bearingless motor, and the bearing ring 34 of the rotor 3 interacts magnetically with the stator ring 71, thereby realizing an additional passive magnetic axial stabilization or axial bearing.

[0095] Fig. 5 A perspective sectional view shows a variant of the first embodiment in one of the Fig. 3 corresponding illustration. For better understanding, it shows Fig. 6 Another schematic section in the axial direction through this variant.

[0096] At the in Fig. 5 und Fig. 6 In the depicted variant, the bearing ring 34 of the rotor 3 is arranged with respect to the axial direction A at a non-zero distance D to the magnetic center plane C of the magnetically effective core 31 of the rotor 3. That is, the bearing ring 34 is arranged such that the geometric center plane LM of the bearing ring 34 no longer lies in the magnetic center plane C, but rather that the geometric center plane LM of the bearing ring 34 is arranged parallel to the magnetic center plane C at a distance D. As shown in the illustration ( Fig. 5, Fig. 6 The bearing ring 34 is arranged above the ring-shaped magnetically active core 31. It is understood that the bearing ring 34 can also be arranged in the same manner as shown in the illustration ( Fig. 5, Fig. 6 ) may be arranged below the magnetically effective core 31.

[0097] In this variant, the two rings, namely the magnetically active core 31 and the bearing ring 34, are no longer arranged concentrically but offset from each other by a distance D with respect to the axial direction A. The centers of the bearing ring 34 and the magnetically active core 31 lie on the same axis, namely the axis of rotation of the rotor 3, but are axially spaced apart from each other. Thus, the bearing ring 34 is centered with respect to the magnetically active core 31 with respect to the radial direction and spaced with respect to the axial direction by a distance D from the magnetically active core 31.

[0098] The connecting element 35 is arranged between the bearing ring 34 and the magnetically effective core 31 and connects the bearing ring 34 to the magnetically effective core 31. The connecting element 35 can be optionally and as shown in Fig.4 as well as Fig. 5 The connecting element 35 extends in a radial direction to the radially inner edge of the magnetically effective core 31.

[0099] The stator ring 71 of the additional bearing stator 7 is arranged concentrically with the bearing ring 34, such that the geometric center plane SM of the stator ring 71 lies in the geometric center plane LM of the bearing ring 34. Consequently, the stator ring 71 is also arranged at a distance D from the magnetic center plane C with respect to the axial direction A. The stator ring 71 surrounds the bearing ring 34, so that the stator ring 71 and the bearing ring 34 are aligned with respect to the radial direction.

[0100] To limit the destabilizing effect of the additional axial support (bearing ring 34 and stator ring 71) on the additional stabilization against tilting to a practically applicable value, embodiments are preferred in which the distance D between the bearing ring 34, more precisely its geometric center plane LM, and the magnetic center plane C is at most one quarter and, more preferably, at most one fifth of the inner radius LR of the bearing ring 34. Preferably, the geometric condition is met that D ≤ LR / 4 and, more preferably, that D ≤ LR / 5.

[0101] Fig. 7 Figure 1 shows a second embodiment of a rotary drive 1 according to the invention in a perspective sectional view, in a representation similar to that shown in Figure 1. Fig. 3 corresponds. For better understanding, shows Fig. 8 A schematic representation of a section in axial direction A through this second embodiment is shown. The following discussion focuses solely on the differences from the first embodiment. Identical or functionally equivalent parts of the second embodiment are designated with the same reference numerals as in the first embodiment and its variants. In particular, the reference numerals have the same meaning as already explained in connection with the first embodiment. It is understood that all preceding explanations of the first embodiment and its variants apply equally or analogously to the second embodiment.

[0102] The second embodiment differs from the first embodiment in that, in the second embodiment, the stator ring 71 of the additional bearing stator 7 is spaced apart from the bearing ring 34 of the rotor 3 with respect to the axial direction A. That is, the stator ring 71 is arranged such that the geometric center plane SM of the stator ring 71 no longer lies in the geometric center plane LM of the bearing ring 34, but rather that the geometric center plane SM of the stator ring 71 is arranged parallel to the geometric center plane LM of the bearing ring 34 at a non-zero distance E. As shown in the illustration ( Fig. 7, Fig. 8 The stator ring 71 is arranged below the bearing ring 34. It is understood that the stator ring 71 is arranged in the same manner as shown in the illustration ( Fig. 7, Fig. 8 ) can be located above the bearing ring 34.

[0103] The stator ring 71 and the bearing ring 34 are no longer arranged concentrically, but offset from each other by a distance E with respect to the axial direction A. The centers of the bearing ring 34 and the stator ring 71 lie on the same axis, namely the axis of rotation of the rotor 3, but are axially spaced apart. Particularly preferably, the stator ring 71 has an inner radius SR that is the same as the inner radius LR of the bearing ring 34. The bearing ring 34 and the stator ring 71 are aligned with each other with respect to the axial direction A, so that the bearing ring 34 and the stator ring 71 are arranged opposite each other or one above the other in the axial direction A.

[0104] At the in Fig. 7 und Fig. 8 In the illustrated embodiment, the bearing ring 34 is arranged in the magnetic center plane C, that is, concentrically with the magnetically effective core 31. In this arrangement, the stator ring 71 is arranged with respect to the axial direction A at a non-zero distance E to the magnetic center plane C, that is, the geometric center plane SM of the stator ring 71 lies parallel to the magnetic center plane C and has a distance E from it.

[0105] Since the stator ring 71 is in Fig. 7 und Fig. 8 In the illustrated embodiment, where the axial part 722 is arranged below the bearing ring 34, it is optional to omit the axial part 722 in the support body 72.

[0106] Fig. 9 A perspective sectional view shows a variant of the second embodiment in one of the Fig. 7 corresponding illustration. For better understanding, it shows Fig. 10 Another schematic section in the axial direction through this variant.

[0107] At the in Fig. 9 und Fig. 10 In the illustrated variant of the second embodiment, the bearing ring 34 of the rotor 3 is arranged with respect to the axial direction A at a non-zero distance D to the magnetic center plane C of the magnetically active core 31 of the rotor 3. That is, the bearing ring 34 is arranged such that the geometric center plane LM of the bearing ring 34 no longer lies in the magnetic center plane C, but rather that the geometric center plane LM of the bearing ring 34 is arranged parallel to the magnetic center plane C at a distance D. As illustrated ( Fig. 9, Fig. 10 The bearing ring 34 is arranged below the ring-shaped magnetically active core 31. It is understood that the bearing ring 34 can also be arranged in the same manner as shown in the illustration ( Fig. 9, Fig. 10 ) can be arranged above the magnetically effective core 31, for example in a manner analogous to that described in connection with Fig. 5 und Fig. 6 was explained.

[0108] In this variant, the two rings, namely the magnetically active core 31 and the bearing ring 34, are no longer arranged concentrically, but offset from each other by a distance D with respect to the axial direction A. The centers of the bearing ring 34 and the magnetically active core 31 lie on the same axis, namely the axis of rotation of the rotor 3, but are axially spaced apart from each other. Thus, the bearing ring 34 is centered with respect to the magnetically active core 31 with respect to the radial direction and spaced with respect to the axial direction by a distance D from the magnetically active core 31.

[0109] The stator ring 71 of the additional bearing stator 7, which is arranged below the bearing ring 34 with respect to the axial direction A, has a distance D + E from the magnetic center plane C in this variant. The three rings, namely the magnetically active core 31, the bearing ring 34, and the stator ring 71, are each arranged in different positions with respect to the axial direction A and parallel to each other. Their centers all lie on the same axis, namely the axis of rotation of the rotor 3 (when the rotor 3 is centered with respect to the stator and is not tilted). The geometric center plane SM of the stator ring 71 lies below the geometric center plane LM of the bearing ring 34 at a distance E, and the latter lies below the magnetic center plane C at a distance D.

[0110] To limit the destabilizing effect of the additional axial support (bearing ring 34 and stator ring 71) on the additional stabilization against tilting to a practically applicable value, embodiments are preferred in which the distance D between the bearing ring 34, more precisely its geometric center plane LM, and the magnetic center plane C is at most one quarter and, more preferably, at most one fifth of the inner radius LR of the bearing ring 34. Preferably, the geometric condition is met that D ≤ LR / 4 and, more preferably, that D ≤ LR / 5.

[0111] As an optional feature, in the Fig. 9 und Fig. 10 In the illustrated variant, the stator ring 71 is radially attached to the radial outer boundary surface of the radial part 721 of the support body 72.

[0112] It is understood that the measures and designs described in connection with the first embodiment and its variant can be combined analogously with the measures and designs described in connection with the second embodiment and its variant.

[0113] The following will now be based on the Fig. 11 - Fig. 14 Variants for the design of the connecting element 35 and / or for the design of the support body 72 are explained. It is understood that these variants can be used for both the first embodiment and its variant, as well as for the second embodiment and its variant.

[0114] Fig. 11 shows a first variant for the design of the connecting element 35 and / or for the design of the supporting body 72 in a perspective view. Fig. 12 This first variant is shown in a perspective section view with a section in axial direction A.

[0115] In this first variant, the connecting element 35, which is arranged radially between the magnetically active core 31 and the bearing ring 34 of the rotor 3, is not designed as a solid disk, but has a plurality of recesses 351, each of which extends completely through the connecting element 35 in the axial direction A. Eight essentially identical recesses 351 are shown here as examples. The recesses 351 are arranged equidistantly with respect to the circumferential direction of the connecting element 35. Each recess 351 has the form of a ring segment, with the common center point of all ring segments coinciding with the geometric center point of the disk-shaped connecting element 35.

[0116] The recesses 351 reduce the material requirement and thus also the weight of the connecting element 35. The recesses 351 are designed, dimensioned, and arranged such that the intervening material of the connecting element 35 still forms a sufficiently stable mechanical connection to fasten the bearing ring 34 to the magnetically effective core 31.

[0117] Similarly, the support body 72, more precisely the radial part 721 of the support body 72, is also provided with a plurality of second recesses 724, each of which extends completely through the radial part 721 of the support body 72 with respect to the axial direction A. Eight essentially identical second recesses 724 are shown here as examples. The second recesses 724 are arranged equidistant with respect to the circumferential direction of the radial part 721. Each second recess 724 has the form of a ring segment, with the common center point of all ring segments coinciding with the geometric center point of the disk-shaped radial part 721 of the support body 72.

[0118] The second recesses 724 reduce the material requirement and thus also the weight of the support body 72. The second recesses 724 are designed, dimensioned, and arranged such that the intervening material of the radial part 721 still forms a sufficiently stable mechanical connection to attach the stator ring 71 to the stator 2.

[0119] Of course, embodiments are also possible in which only the recesses 351 are provided in the connecting element 35, or only the second recesses 724 in the support body 72.

[0120] Fig. 13 shows a second variant for the design of the connecting element 35 and / or for the design of the supporting body 72 in a perspective view. Fig. 14 This second variant is shown in a perspective section view with a section in axial direction A.

[0121] In this second variant, the connecting element 35 has a plurality of spokes 352, each of which extends radially between the magnetically effective core 31 of the rotor 3 – or optionally a sheathing of the magnetically effective core 31 (not shown) – and the bearing ring 34 of the rotor 3 – or optionally a sheathing of the bearing ring 34 (not shown). Each spoke 352 connects the magnetically effective core 31 to the bearing ring 34.

[0122] Eight essentially identical spokes 352 are provided here as an example. The spokes 352 are arranged equidistant with respect to the circumferential direction of the connecting element 35. The spokes 352 are designed, dimensioned, and arranged such that they form a sufficiently stable mechanical connection to fasten the bearing ring 34 to the magnetically effective core 31.

[0123] Similarly, the support body 72, more precisely the radial part 721 of the support body 72, is also designed with a plurality of second spokes 725, each of which extends radially between the stator 2 – or optionally a stator housing (not shown) – and the annular axial part 722 of the support body 72. Each second spoke 725 connects the stator 2 – or a stator housing (not shown) – to the axial part 722 of the support body 72.

[0124] Eight essentially identical second spokes 725 are provided here as an example. The second spokes 725 are arranged equidistant with respect to the circumferential direction of the support body 72. The second spokes 725 are designed, dimensioned, and arranged such that they form a sufficiently stable mechanical connection to fasten the stator ring 71 to the stator 2.

[0125] Of course, embodiments are also possible in which only the spokes 352 are provided in the connecting element 35, or only the second spokes 725 in the support body 72.

[0126] In the Fig. 15 und Fig. 16 A variant for the design of the bearing ring 34 and / or for the design of the stator ring 71 is described. It is understood that this variant can be used for both the first embodiment and its variant, as well as for the second embodiment and its variant.

[0127] According to this variant, the bearing ring 34 and the stator ring 71 are each designed in a segmented form. Fig. 15 This variant is shown in a perspective view using the example of an embodiment of the rotary drive 1, which is otherwise the one described in Fig. 3 The illustrated embodiment corresponds to this. For better understanding, it shows Fig. 16 this variant from Fig. 15 still in a perspective sectional view.

[0128] Both the bearing ring 34 and the stator ring 71 are made of a permanent magnetic material and are each segmented with a plurality of permanent magnets 341 and 711 respectively.

[0129] Each of the permanent magnets 341 of the bearing ring 34 is designed as a ring segment. All permanent magnets 341 are magnetized in the same direction, here in the axial direction A upwards. This is in Fig. 16 The direction of magnetization is indicated by the arrows without reference symbols in the bearing ring 34. For illustrative purposes, the bearing ring 34 consists of twenty-four identical individual permanent magnets 341, each designed as a ring segment. The permanent magnets 341 are arranged circumferentially, with two adjacent permanent magnets 341 directly abutting each other, so that the entirety of the permanent magnets 341 forms the permanent magnet bearing ring 34. Each of the permanent magnets 711 of the stator ring 71 is designed as a ring segment. All permanent magnets 711 are magnetized in the same direction, here in the axial direction A downwards. This is shown in Fig. 16 The direction of magnetization is indicated by the arrows without reference symbols in the stator ring 71. For illustrative purposes, the stator ring 71 consists of twenty-four identical individual permanent magnets 711, each of which is designed in the form of a ring segment. The permanent magnets 711 are arranged circumferentially, with two adjacent permanent magnets 711 directly abutting each other, so that the entirety of the permanent magnets 711 forms the permanent magnet stator ring 71.

[0130] The segmented design of the bearing ring 34 or the stator ring 71 is preferred because it allows for simpler manufacturing, but it is of course also possible to design the bearing ring 34 and / or the stator ring 71 as a single-piece ring.

[0131] If the bearing ring 34 and / or the stator ring 71 is designed with permanent magnets, it is not necessary for the respective ring 34 or 71 to consist entirely of a permanent magnetic material or to comprise only permanent magnets. It is also possible to design the ring in which a permanent magnet bearing ring 34 and / or a permanent magnet stator ring 71 each comprise a plurality of permanent magnets between which ferromagnetic connecting pieces are arranged. In a segmented design of the respective ring 34 or 71, several permanent magnet ring segments can then be provided, which are connected to each other by ferromagnetic ring segments.

[0132] As already mentioned, it is preferred, but not necessary, that both the bearing ring 34 and the stator ring 71 are designed as permanent magnet rings. Embodiments are also possible in which either only the bearing ring 34 or only the stator ring 71 is designed as a permanent magnet. If only the bearing ring 34 is a permanent magnet, then the stator ring 71 is designed as a ferromagnet, for example as an iron ring or a ring made of another ferromagnetic material.

[0133] If the bearing ring 34 or the stator ring 71 is designed to be ferromagnetic, then this ring 34 or 71 can be designed as a one-piece ring or as a segmented ring in the same manner as described above.

[0134] For the preferred embodiment, in which both the bearing ring 34 and the stator ring 71 are each designed with a permanent magnet, it is shown in the Fig. 3 - Fig. 16 The same form of magnetization of the stator ring 71 and the bearing ring 34 is always shown, namely that the bearing ring 34 and the stator ring 71 are each magnetized in axial direction A, with the magnetization of the stator ring 71 (downwards, as shown) being directed opposite to the magnetization of the bearing ring 34 (upwards, as shown). Besides this preferred embodiment, there are also other preferred embodiments with regard to the magnetization of the stator ring 71 and the bearing ring 34. These will be described below using the following examples. Fig. 17 - Fig. 21 Various options for magnetizing the bearing ring 34 and the stator ring 71 are explained. It is understood that these options can be used for both the first embodiment and its variant, as well as for the second embodiment and its variant.

[0135] The Fig. 17 - Fig. 21 Each figure shows a schematic sectional view of an embodiment of the rotary drive 1. In each of the Fig. 17 - Fig. 21 The arrows without reference numerals in the bearing ring 34 indicate the direction of the magnetization of the bearing ring 34, and the arrows without reference numerals in the stator ring 71 indicate the direction of the magnetization of the stator ring 71.

[0136] Fig. 17 The first embodiment shows a variant in which the stator ring 71 and the bearing ring 34 are each magnetized in a radial direction, wherein the magnetization of the stator ring 71 and the magnetization of the bearing ring 34 are in the same direction, namely radially outwards.

[0137] Fig. 18 The first embodiment shows a variant in which the stator ring 71 is magnetized in the radial direction and the bearing ring 34 is magnetized in the axial direction A. The magnetization of the stator ring 71 is directed radially outwards, and the magnetization of the bearing ring 34 is directed upwards in the axial direction A.

[0138] Fig. 19 The first embodiment shows a variant in which the stator ring 71 is magnetized in the axial direction A and the bearing ring 34 is magnetized in the radial direction. The magnetization of the stator ring 71 is directed downwards in the axial direction A, and the magnetization of the bearing ring 34 is directed radially outwards.

[0139] Fig. 20 The second embodiment shows a variant in which the stator ring 71 and the bearing ring 34 are each magnetized in the axial direction, with the magnetization of the stator ring 71 and the magnetization of the bearing ring 34 being directed in opposite directions. The magnetization of the stator ring 71 is directed downwards in axial direction A, and the magnetization of the bearing ring 34 is directed upwards in axial direction A.

[0140] Fig. 21 The second embodiment shows a variant in which the stator ring 71 and the bearing ring 34 are each magnetized in a radial direction, wherein the magnetization of the stator ring 71 and the magnetization of the bearing ring 34 are in the same direction, namely radially outwards.

[0141] The invention further proposes a rotation device for treating a surface of a disc-shaped body, with which the body can be rotated for treatment, characterized in that the rotation device comprises an electromagnetic rotary drive 1, which is designed according to the invention, wherein the rotor 3 comprises a holder for the disc-shaped body.

[0142] Fig. 22 Figure 1 shows a perspective view of an embodiment of a rotating device according to the invention for treating the surface of a disk-shaped body. The rotating device is collectively designated by reference numeral 100 and the disk-shaped body by reference numeral 110. For better understanding, Figure 2 shows... Fig. 23 Another perspective sectional view of the rotating device 100 in a section in axial direction A and Fig. 24 a schematic sectional view of the rotating device 100 in a section along the axial direction A.

[0143] The following example refers to a practical application from the semiconductor industry, where the object to be treated is a wafer for the production of electronic components, i.e., a thin, disk-shaped body. The rotary device 100 can be used to treat the surface 111 of the wafer, for example, to apply fluids such as suspensions to the surface 111 in a controlled manner. Examples include chemical-mechanical polishing (CMP) processes using slurry, cleaning and / or etching of wafers, application of photoresist, or removal of photoresist with solvents. In addition to these wet processes, in which the wafer 110 is exposed to a fluid, the rotary device 100 is also suitable for dry processes.Examples of such drying processes in which the wafer 110 is rotated include: plasma etching, rapid thermal processing (RTP), atomic layer deposition (ALD), chemical vapor deposition (CVD), or physical vapor deposition (PVD).

[0144] In such processes, the wafers 110 are typically placed in rapid rotation in a process chamber 20 and then treated with the respective fluid, radiation, plasma, or substances to be deposited. The rotating device 100 according to the invention is particularly suitable for processes in which the process chamber 20 must be evacuated, and especially for processes carried out in a high vacuum.

[0145] Typically, in all these processes, the stator 2 and the additional bearing stator 7 are arranged outside the process chamber 20, while the rotor 3 is arranged inside the process chamber 20.

[0146] In the Fig. 22 - Fig. 24 In the illustrated embodiment, the rotary device 100 comprises the electromagnetic rotary drive 1, which here is according to the first embodiment ( Fig. 3 ) is designed. Furthermore, a trial chamber 20 is provided, from which in the Fig. 22 - Fig. 27 Only those areas of the process chamber wall that separate the stator 2 from the rotor 3 are shown. It is understood that the entire process chamber 20 is designed such that the rotor 3 with the wafer 110 is completely within the closable process chamber 20. The stator 2 and the additional bearing stator 7 are arranged outside the process chamber 20. How this is best illustrated in Fig. 23 and Fig. 24 As can be seen, the process chamber 20 is designed such that it extends between the rotor 3 on the one hand and the stator 2 and the additional bearing stator 7 on the other hand; that is, the stator 2 and the additional bearing stator 7 are arranged outside the process chamber 20, while the rotor 3 with the wafer 110 is arranged inside the process chamber 20. The process chamber 20 also includes a wall section 201 ( Fig. 24 ) and a centrally arranged hollow cylindrical part 202, which is arranged within the annular return 22 of the stator 2. From the hollow cylindrical part 202, the wall part 201 extends radially outwards, initially running above the coils 61 of the stator 2, then below the rotor 3 along the magnetically effective core 31, the connecting element 35 and the bearing ring 34, and subsequently above the stator ring 71 of the additional bearing stator 7.

[0147] This design has the advantage that the stator 2 and the additional bearing stator 7 can be arranged outside the process chamber 20 in which the wafer 110 is processed, while the rotor 3 with the wafer 110 can be arranged inside the process chamber 20. The hollow cylindrical part 202 of the process chamber 20 provides access to the process chamber 20, through which, for example, fluids can be discharged from or introduced into the process chamber 20. Furthermore, the hollow cylindrical part 202 can be used more generally as an access point to the process chamber 20, for example, for electrical supply or signal lines connected to heaters, plasma sources, radiation sources, sensors, etc. The hollow cylindrical part 202 can also be used for supplying and removing a cooling fluid from the process chamber 20.

[0148] The rotor 3 includes a holder 120 for holding or fixing the wafer 110 on the rotor 3. The holder 120 comprises a plurality of retaining arms 121, which are distributed equidistantly around the rotor 3 in the circumferential direction. In the embodiment described here, eight substantially identical retaining arms 121 are provided. Each retaining arm 121 is arranged on the connecting element 35 of the rotor 3 and fixed to the connecting element 35, so that each retaining arm 121 is rotationally fixed to the connecting element 35 and thus also rotationally fixed to the rotor 3. It is also possible that all retaining arms 121 are an integral part of the connecting element 35, i.e., that the connecting element 35 is formed in one piece with all retaining arms 121.

[0149] Each retaining arm 121 extends radially outwards from the connecting element 35 and above the bearing ring 34 of the rotor 3. The radially outer end of each retaining arm 121 is designed to receive the wafer 110. For this purpose, the radially outer end of each retaining arm 121 can have a stop, a recess, or another type of retaining mechanism for the wafer 110, so that the wafer 110 can be held on the rotor 3 by the entirety of the retaining arms 121, or can be fixed to the rotor 3. The radially outer ends of the retaining arms 121 all lie on a circle whose diameter corresponds to the diameter DK of the wafer 110.

[0150] To treat the wafer 110 or its surface 111, the wafer 110 is placed in the holder 120 and then rotated with the rotor 3.

[0151] The in the Fig. 22 - Fig. 24 The illustrated embodiment of the rotary device 100 is particularly suitable for the treatment of large wafers 110 whose diameter DK is larger than the outer diameter of the stator ring 71 or the bearing ring 34.

[0152] Fig. 25 shows a variant of the in a perspective view. Fig. 22 - Fig. 24 The illustrated embodiment of a rotary device 100 according to the invention for treating the surface 111 of the disk-shaped body 110 is shown. For better understanding, Fig. 26 Another perspective sectional view of this variant in a section in axial direction A and Fig. 27 a schematic sectional view of this variant in a section along the axial direction A.

[0153] The variant of the rotary device 100 differs in the design of the holder 120 for the wafer 110. This variant is designed for smaller wafers 110 whose outer diameter DK is smaller than the inner diameter of the bearing ring 34. The retaining arms 121, which are arranged equidistantly on the connecting element in the circumferential direction, are each designed as a rod-shaped retaining arm 121 extending in the axial direction A.

[0154] It is understood that the inventive rotary device 100 for treating the surface 111 of the disk-shaped body 110 can also be equipped with an electromagnetic rotary drive 1, which according to the second embodiment ( Fig. 7 ) is designed in which the stator ring 71 is spaced apart from the bearing ring 34 with respect to the axial direction A, in particular below the bearing ring 34.

[0155] The invention further proposes a rotary device for conveying, mixing or stirring fluids, characterized in that the rotary device comprises an electromagnetic rotary drive 1, which is designed according to the invention, wherein the rotor 3 of the rotary drive 1 is designed as the rotor 3 of the rotary device.

[0156] Fig. 28 Figure 1 shows a perspective view of an embodiment of a rotary device according to the invention, which is configured as a mixing device. The mixing device is collectively designated by reference numeral 200. For better understanding, Figure 2 shows... Fig. 29 Another perspective sectional view of the mixing device 200 in a section in axial direction A and Fig. 30 a schematic sectional view of the mixing device 200 in a section along the axial direction A.

[0157] In the Fig. 28 - Fig. 30 In the illustrated embodiment, the mixing device 200 comprises the electromagnetic rotary drive 1, which here is according to the second embodiment ( Fig. 7 ) is designed in which the stator ring 71 is spaced apart from the bearing ring 34 with respect to the axial direction A. The stator ring 71 is as shown ( Fig. 29, Fig. 30 ) arranged below the bearing ring 34 such that the stator ring 71 and the bearing ring 34 are aligned with each other with respect to the axial direction A.

[0158] The rotor 3 comprises a plurality of vanes 210 for mixing or stirring fluids. In the embodiment described here, a total of four vanes 210 are provided, although this number is exemplary. All vanes 210 are arranged on the connecting element 35 and are equidistant with respect to the circumferential direction of the rotor 3. Each vane 210 extends radially outwards and is rotationally fixed to the connecting element 35 and thus also to the rotor 3. The vanes 210 can be separate components that are then fixed to the connecting element 35. It is also possible, of course, for all vanes 210 to be an integral part of the connecting element 35, i.e., for the connecting element 35 to be formed in one piece with all the vanes 210. The rotor 3 with the vanes 210 forms the impeller or the wheel of the mixing device 200, which acts on the fluid or fluids.

[0159] An advantageous aspect is that rotor 3 is designed as an integral rotor, because it serves both as rotor 3 of the electromagnetic rotary drive 1 and as rotor 3 of the mixing device 200, which can be used to convey, mix, or stir fluids. Overall, rotor 3 thus fulfills three functions in one: it is the rotor of the electromagnetic drive, it is the rotor of the magnetic bearing, and it is the impeller that acts on the fluid(s). This integral rotor design offers the advantage of a very compact and space-saving construction.

[0160] The mixing device 200 further comprises a mixing container 220 with a dimensionally stable base 221. The mixing container 220 is divided into the Fig. 28 und Fig. 29 Only the base 221 is shown. The mixing vessel 220 serves to hold the fluid or fluids that are to be mixed or stirred. In addition to the dimensionally stable base 221, the mixing vessel 220 comprises at least one further wall 223 ( Fig. 30 ), which delimits the mixing vessel 220. This wall 223 is in Fig. 28 und Fig. 29 not shown and in Fig. 30 The wall 223 can be designed as a dimensionally stable wall, for example made of a plastic. Alternatively, the wall 223 can be designed as a flexible wall 223, preferably also made of a plastic. The flexible wall 223, together with the dimensionally stable base 221, then forms the mixing container 220 for receiving the substances to be mixed or stirred. This mixing container 220 is then designed as a flexible bag, for example as a plastic bag, which can be folded so that it takes up as little space as possible during storage. This design of the mixing container 220 is particularly suitable for single-use applications, in which the mixing container 220 with the rotor 3 arranged therein is intended to be used only once and is replaced by a new mixing container for subsequent applications.

[0161] It is understood that the mixing device 200 or the mixing container 220 can also be designed for multiple applications, i.e., for multiple uses. For multiple applications, it is preferred if the entire mixing container 220 is dimensionally stable. Preferably, the mixing container 220 is then made of stainless steel, but it can also be made of plastic, glass, or another material.

[0162] The dimensionally stable base 221 of the mixing vessel 220 comprises a containment shell 222 for receiving the stator 2 of the rotary drive 1. The containment shell 222 is arranged centrally in the base 221 and within the annular, magnetically active core 31 of the rotor 3, such that the magnetically active core 31 of the rotor 3 surrounds the containment shell 222 during operation. The containment shell 222 is dimensioned such that the magnetically active core 31 of the rotor 3, or a casing (not shown), encloses the containment shell 222 with minimal clearance.

[0163] How this is particularly Fig. 29 und Fig. 30 As shown, the dimensionally stable base 221 with the containment pot 222 in the mixing device 200 is designed and arranged such that the containment pot 222 is located between the stator poles 21 of the stator 2 and the magnetically active core 31 of the rotor 3, and that the dimensionally stable base 221 extends radially between the magnetically active core 31, the connecting element 35, and the bearing ring 34 of the rotor 3 on the one hand, and the support body 72 and the stator ring 71 of the additional bearing stator 7 on the other. In the assembled state, the stator 2 and the additional bearing stator 7 are thus located outside the mixing container 220, while the rotor 3 with the blades 210 is located inside the mixing container 220.

[0164] This embodiment of the mixing device 200 is particularly suitable for embodiments that include components for single use. The mixing device preferably has a single-use component and a reusable component designed for multiple uses.

[0165] The term "single-use device" and other compound words containing "single-use" refer to components or parts designed for single use, meaning they are intended to be used only once and then disposed of. For a new application, a new, previously unused single-use part must be inserted. Therefore, a key aspect in the design and development of the single-use device is that it can be easily assembled with the reusable device to form the mixing device 200. The single-use device should be replaceable very easily, without requiring extensive assembly. Ideally, the single-use device should be able to be assembled with and separated from the reusable device without the use of tools.

[0166] In the mixing device 200, the disposable device comprises the mixing container 220 with the rotor 3 located therein, and the reusable device comprises the stator 2 and the additional bearing stator 7.

[0167] In order to achieve the simplest possible design and assembly / disassembly of the disposable device and the reusable device, it is advantageous that the rotary drive 1 according to the second embodiment ( Fig. 7 The mixing vessel 220 is designed in such a way that the stator ring 71 is spaced apart from the bearing ring 34 with respect to the axial direction A. This allows the mixing vessel 220 to be easily assembled with and separated from the stator 2 and the additional bearing stator 7. To assemble the vessel, it is simply necessary to place the containment cup 222 over the stator 2, and the mixing device 200 is then ready for use. After use, the mixing vessel 210 can be easily separated again from the stator 2 and the additional bearing stator 7.

[0168] It is understood that the mixing device 200 can also be designed as a whole as a reusable device, i.e., for multiple uses. In such a configuration, the mixing container 220 with the rotor 3 arranged therein is also designed for multiple uses.

[0169] The rotary device configured as a mixing device 200 can be used particularly in the pharmaceutical and biotechnology industries. The mixing device 200 is especially suitable for applications where a very high degree of purity or sterility of the components that come into contact with the substances to be mixed is essential. The mixing device 200 can also be configured as a bioreactor or fermenter. However, it is understood that the mixing device 200 is not limited to such configurations, but can be configured more generally as a mixing device 200 with which media or substances can be mixed or stirred. In particular, these substances can be fluids or solids, preferably powders.The mixing device 200 is suitable for mixing liquids with each other and / or for mixing at least one liquid with a powder or other solid and / or for mixing gases with liquids and / or solids.

[0170] It is understood that the inventive rotary device 200 for conveying, mixing or stirring fluids can also be equipped with an electromagnetic rotary drive 1, which according to the first embodiment ( Fig. 3 ) is designed in which the stator ring 71 is arranged concentrically with the bearing ring 34, so that the stator ring 71 surrounds the bearing ring 34.

Claims

1. An electromagnetic rotary drive, which is designed as an external rotor, having a rotor (3) comprising a ring-shaped and permanent-magnetically designed magnetically effective core (31) being arranged around a stator (2) and having a magnetic central plane (C), wherein the stator (2) is designed as a bearing and a drive stator, with which, in the operating state, the rotor (3) is contactlessly magnetically drivable about a desired axis of rotation defining an axial direction (A), and with which the rotor (3) is contactlessly magnetically levitatable with respect to the stator (2), wherein the rotor (3) is actively magnetically levitated in a radial plane perpendicular to the axial direction (A), and is passively magnetically stabilized in axial direction (A) and against tilts, wherein the stator (2) comprises coils (61), by means of which a magnetic rotary field can be generated, which, on the one hand, exerts a torque on the magnetically effective core (31) of the rotor (3), causing it to rotate, and which, on the other hand, exerts an arbitrarily adjustable transverse force on the magnetically effective core (31) of the rotor (3), so that its radial position - i.e., its position in the radial plane - can be actively controlled or regulated, wherein the rotor (3) comprises a magnetically effective bearing ring (34), which is arranged radially externally disposed and spaced from the magnetically effective core (31) of the rotor (3), wherein an additional bearing stator (7) having a magnetically effective stator ring (71) is provided for interaction with the bearing ring (34), wherein the additional bearing stator (7) is designed and arranged in such a way that the stator ring (71) passively magnetically stabilizes the rotor (3) against tilts, wherein the bearing ring (34) is connected to the magnetically effective core (31) of the rotor (3) via a connecting element (35) made of a low-permeable material, wherein both the bearing ring (34) of the rotor (3) and the stator ring (71) of the additional bearing stator (7) each comprise at least one permanent magnet (341, 711), and wherein the additional bearing stator (7) comprises a supporting body (72) for supporting the stationary stator ring (71).

2. A rotary drive according to claim 1, wherein the bearing ring (34) of the rotor (3) is arranged in the magnetic central plane (C) of the magnetically effective core (31) of the rotor (3).

3. A rotary drive according to claim 1, wherein the bearing ring (34) is arranged with respect to the axial direction (A) at a distance (D) different from zero to the magnetic central plane (C) of the magnetically effective core (31) of the rotor (3), and wherein said distance (D) is at most one quarter, preferably at most one fifth, of the inner radius (LR) of the bearing ring (34).

4. A rotary drive according to anyone of the preceding claims, wherein the stator ring (71) of the additional bearing stator (7) is arranged concentrically with the bearing ring (34) of the rotor (3) such that the stator ring (71) surrounds the bearing ring (34) radially externally disposed.

5. A rotary drive according to anyone of the claims 1 to 3, wherein the stator ring (71) of the additional bearing stator (7) is arranged spaced from the bearing ring (34) of the rotor (3) with respect to the axial direction (A), and wherein the stator ring (71) preferably has the same inner radius (SR) as the bearing ring (34).

6. A rotary drive according to anyone of the preceding claims, wherein the connecting element (35) has a disk-shaped design and optionally has a plurality of recesses (351).

7. A rotary drive according to anyone of the claims 1 to 5, wherein the connecting element (35) comprises a plurality of spokes (352) each extending in radial direction between the magnetically effective core (31) of the rotor (3) and the magnetically effective bearing ring (34) of the rotor (3).

8. A rotary drive according to anyone of the preceding claims, wherein the stator ring (71) and the bearing ring (34) each consist of a permanent magnetic material and are each designed segmented with a plurality of permanent magnets (341, 711).

9. A rotary drive according to anyone of the preceding claims, wherein the stator ring (71) and the bearing ring (34) each are magnetized in axial direction (A), and the magnetization of the stator ring (71) being directed in the opposite direction to the magnetization of the bearing ring (34).

10. A rotary drive according to anyone of the preceding claims, wherein the stator ring (71) and the bearing ring (34) each are magnetized in radial direction, the magnetization of the stator ring (71) and the magnetization of the bearing ring (34) being directed in the same direction, and preferably the magnetization of the stator ring (71) and the magnetization of the bearing ring (34) each being directed radially outwards.

11. A rotary drive according to anyone of the preceding claims, wherein either the stator ring (71) is magnetized in axial direction (A) and the bearing ring (34) is magnetized in radial direction, or the stator ring (71) is magnetized in radial direction and the bearing ring (34) is magnetized in axial direction (A).

12. A rotational device for treating a surface (111) of a disk-shaped body (110) with which the body (110) is rotatable for treatment, characterized in that the rotational device (100) comprises an electromagnetic rotary drive (1) being designed according to anyone of the claims 1 to 11, wherein the rotor (3) comprises a holder (120) for the disk-shaped body (110).

13. A rotational device for conveying, mixing or stirring fluids, characterized in that the rotational device (200) comprises an electromagnetic rotary drive (1) being designed according to anyone of the claims 1 to 11, wherein the rotor (3) of the rotary drive (1) is designed as rotor (3) of the rotational device (200).

14. A rotational device according to claim 13, wherein the rotor (3) has a plurality of vanes (210) for mixing or stirring fluids, the vanes (210) being arranged on the connecting element (35).