Magnetic suspension device and electromagnetic rotary driver

Abstract

The invention relates to a magnetic levitation device for contactless magnetic levitation of a rotor, the rotor having a disc-shaped or annular magnetically effective core, the magnetic levitation device having a stator with cup-shaped recesses, the cup-shaped recesses being arranged at the axial ends of the stator and the rotor being insertable into the cup-shaped recesses, the stator having a plurality of coil cores, each of the plurality of coil cores has a longitudinal leg and a pole piece, where each longitudinal leg extends in an axial direction from a first end to a second end, where a contact surface is arranged at the second end, where each pole piece extends at least partially in a radial direction from the contact surface to an end face, where the radial direction is perpendicular to the axial direction. Wherein the end face is arranged around the cup-shaped recess, at least one concentrated winding is arranged at each longitudinal leg, the concentrated winding surrounds the corresponding longitudinal leg, each pole piece is made of transverse elements in the form of metal plates, and the transverse elements are stacked in the axial direction. The invention further relates to an electromagnetic rotary drive having such a magnetic suspension device.

Description

Technical Field

[0001] The invention relates to a magnetic levitation device according to the preamble of the independent patent claim and to an electromagnetic rotary drive having such a magnetic levitation device. Background Art

[0002] Magnetic bearing arrangements for contactless magnetic bearings of rotors have the following advantages: they do not require mechanical bearings for the rotor. The rotor is supported or stabilized by means of magnetic forces generated by the stator of the magnetic bearing arrangement. Since there are no mechanical bearings, such magnetic bearing arrangements are particularly suitable for pumping, mixing, centrifuging, or stirring devices that transport very sensitive substances, such as blood pumps, or that have very high purity requirements, such as in the pharmaceutical or biotechnology industries, or that transport abrasive or corrosive substances that would quickly destroy mechanical bearings, such as in pumps or mixers for slurries, sulfuric acid, phosphoric acid, or other chemicals in the semiconductor industry.

[0003] In the biotechnology industry, such magnetic bearings are used, for example, in conjunction with bioreactors, for example in centrifugal pumps for conveying fluids into and out of bioreactors, or in mixing devices for mixing fluids within bioreactors. In the semiconductor industry, such magnetic bearings are used not only for conveying aggressive or abrasive substances but also in rotating devices, for example, for rotating wafers.

[0004] It is also known to use magnetic bearing arrangements for viscometers.

[0005] An advantageous design of a magnetic bearing device known per se is a design in the form of a temple, to which the present invention also relates.

[0006] The temple-like structure is characterized in that the stator of the magnetic bearing device has a plurality of coil cores, each of the plurality of coil cores including a longitudinal leg extending in an axial direction from a first end to a second end. Here, the axial direction refers to the direction defined by the desired axis of rotation of the rotor supported by the magnetic bearing device. The desired axis of rotation is the axis of rotation about which the rotor rotates when it is in a centered and non-tilted position relative to the stator in the operating state. In addition to the longitudinal legs, each coil core also includes a transverse leg (also called a pole piece), which is arranged at the second end of the longitudinal leg in each case and extends in a radial direction (usually toward the inside), wherein the radial direction is perpendicular to the axial direction. Therefore, the transverse legs extend essentially at right angles to the longitudinal legs. The coil cores each have an L-shape, wherein the transverse legs form the short legs of the L. The rotor to be supported is then arranged between the transverse legs.

[0007] The multiple longitudinal legs extending in the axial direction and reminiscent of temple columns give this construction its name.

[0008] In one embodiment, the stator of the magnetic bearing arrangement has, for example, six coil cores arranged circularly and equidistantly around a cup-shaped recess into which the rotor can be inserted. The first ends of the longitudinal legs are typically connected in the circumferential direction via a back iron for conducting the magnetic flux. The supported rotor comprises a magnetically active core, such as a permanent magnetic disk or a permanent magnet ring, which is arranged between the radially inner ends of the transverse legs and which rotates in the axial direction in the operating state, wherein the rotor is magnetically supported in a contactless manner relative to the stator.

[0009] For such magnetic bearing arrangements, it is not necessarily the case that the magnetically active core of the rotor must be designed as a permanent magnet. Designs are also known in which the magnetically active core of the rotor is designed as a non-permanent magnet, i.e., without permanent magnets. The magnetically active core of the rotor is then, for example, designed as a ferromagnetic material and made, for example, of iron, nickel iron, cobalt iron, silicon iron, μ-metal, or another ferromagnetic material.

[0010] Furthermore, designs are possible in which the rotor's magnetically active core comprises both ferromagnetic and permanent magnet materials. For example, permanent magnets can be placed or inserted into a ferromagnetic matrix. This design is advantageous, for example, if one wishes to reduce the cost of a large rotor by conserving permanent magnet material.

[0011] The longitudinal legs carry the windings that generate the electromagnetic fields necessary for the contactless magnetic bearing of the rotor. For example, the windings are designed so that one concentrated winding is wound around each longitudinal leg, i.e., the coil axis of each concentrated winding extends in the axial direction. In this case, it is typical for a temple-like design that the coil axes of the concentrated windings extend in the axial direction and that the concentrated windings are not arranged in the radial plane in which the rotor or its magnetically active core is supported in the operating state.

[0012] A design in which exactly one concentrated winding is arranged on each longitudinal leg is possible. In other designs, several, for example exactly two, concentrated windings are provided on each longitudinal leg. A design is also possible in which a winding is provided that is wound around two longitudinal legs that are adjacent in the circumferential direction, such that both adjacent longitudinal legs are located within the interior space of the concentrated winding.

[0013] The coil cores of magnetic bearing devices known from the prior art are usually designed as metal plates. This means that several metal plates in the shape of the coil core are stacked insulated from one another in the circumferential direction.

[0014] The sheet metal design of the coil core prevents eddy currents for magnetic fields extending in the direction of the sheet metal, ie magnetic fields following the longitudinal legs in the axial direction and the transverse legs in the radial direction.

[0015] For magnetic fields emerging laterally (ie in the circumferential direction) from the metal plates of the longitudinal and transverse legs, the insulation of the metal plates is ineffective and therefore eddy currents still occur since these magnetic fields pass orthogonally through the metal plates.

[0016] Especially in the case of magnetic bearing arrangements with a large magnetic gap, where the magnetic gap is defined as the distance in radial direction between the end faces of the pole pieces and the magnetically active core of the rotor, the orthogonal field components cannot be neglected and generate significant eddy current losses.

[0017] In the context of this application, a large magnetic gap means a magnetic gap that is greater than 1% of the diameter of the magnetically active core in the radial direction. In some cases, the magnetic gap may be greater than or equal to 5% of the diameter of the magnetically active core in the radial direction. Summary of the Invention

[0018] Starting from this prior art, the object of the present invention is therefore to provide a magnetic levitation device for contactless magnetic levitation of a rotor having a disk-shaped or annular magnetic active core, which has lower eddy current losses than the previous prior art.

[0019] Furthermore, the object of the present invention is to provide an electromagnetic rotary drive having such a magnetic levitation device.

[0020] The subject matter of the invention which meets this object is characterized by the features of the independent patent claims.

[0021] Therefore, according to the present invention, a magnetic levitation device for contactless magnetic levitation of a rotor is proposed, the rotor having a disk-shaped or annular magnetically active core, wherein the magnetic levitation device has a stator having a cup-shaped recess, which is arranged at an axial end of the stator and into which the rotor can be inserted, wherein the stator has a plurality of coil cores, each of the plurality of coil cores having a longitudinal leg and a pole piece, wherein each longitudinal leg extends from a first end in the axial direction to a second end, wherein a contact surface is arranged at the second end, wherein each pole piece extends from the contact surface at least partially in a radial direction to an end face, wherein the radial direction is perpendicular to the axial direction, wherein the end face is arranged around the cup-shaped recess, wherein at least one concentrated winding is arranged at each longitudinal leg, wherein at least one concentrated winding surrounds the respective longitudinal leg, wherein each pole piece is made of a transverse element in the form of a metal sheet, and wherein the transverse elements are stacked in the axial direction.

[0022] Most of the eddy current losses occur at the pole pieces because the distance between adjacent pole pieces is particularly small, especially at their ends facing the cup-shaped recess. The reason for this is that the eddy current losses are mainly caused by the orthogonal field (i.e., the field that penetrates the transverse element orthogonally). Such an orthogonal field has the possibility of flowing from the pole piece of the first coil core to the pole piece of the adjacent second coil core in the circumferential direction, especially when there is a small distance between the pole pieces. Due to the transverse elements of the pole pieces stacked in the axial direction, the orthogonal field in the circumferential direction is prevented. This results in the fact that the eddy current losses are greatly reduced.

[0023] This results in another important advantage. The end faces of the pole pieces can be arranged much closer together in the circumferential direction, because the field flowing from a pole piece of a first coil core to a pole piece of an adjacent second coil core in the circumferential direction flows parallel to the axially stacked transverse elements and therefore does not generate any eddy current losses. This can, for example, improve the passive stiffness and active suspension forces and / or enable a more compact design of the stator.

[0024] Several possible connection methods can be used to attach the pole piece to the longitudinal leg. In particular, these methods include force-locking connection methods (such as clamping or crimping), form-locking connection methods (such as screwing or plugging), or material-locking connections (such as gluing). It is also possible to connect the longitudinal leg and the pole piece via a tongue-and-groove joint and / or a plug (such as a pin, a tines, or a dovetail joint). In a preferred embodiment, the material-locking connection method is achieved by gluing.

[0025] According to a preferred embodiment, each longitudinal leg is made of a longitudinal element in the form of sheet metal, wherein the longitudinal elements are stacked in the circumferential direction of the stator.

[0026] According to a preferred embodiment, the transverse elements and / or the longitudinal elements are made of electrical metal sheet.

[0027] According to the general definition, electrical sheet metal is understood to be a soft magnetic material used for magnetic cores. Materials with a low coercive field strength are often referred to as soft magnetic materials. The coercive field strength is the magnetic field strength required to demagnetize the material. Within the framework of this application, a soft magnetic material is understood to be a material with a coercive field strength, more precisely, a coercive field strength of the magnetic polarization, which is less than 2,000 A / m.

[0028] There is also the possibility of using μ-metal for the transverse elements and / or the longitudinal elements.

[0029] According to a preferred embodiment, the contact surface is designed in a planar manner and is arranged at a surface of the longitudinal leg that is perpendicular to the radial direction. In this case, the contact surface is particularly preferably arranged at the second end of the longitudinal leg.

[0030] According to a preferred embodiment, the end face of the pole piece is designed as a curved surface. Particularly preferably, the end face is designed and arranged coaxially with the cup-shaped recess. In other words, the end face of the pole piece is a segment of a cylindrical surface, wherein the central axis of the cylinder coincides with the central axis of the cup-shaped recess, and the radius of the cylinder is greater than the radius of the cup-shaped recess, so that the end face does not protrude into the cup-shaped recess.

[0031] Furthermore, it is preferred that the end surface be designed to be wider relative to the circumferential direction than the maximum circumferential extension of the contact surface. This means that one of the two circumferentially extending edges of the end surface is longer than one of the circumferentially extending edges of the contact surface. If the end surface is designed as a curved surface, the length of one of the arcs of the cylindrical surface segment in a radial plane is greater than the length of one of the circumferentially extending edges of the contact surface.

[0032] This widening of the end surface in the circumferential direction has the advantage of being beneficial to the magnetic function, for example, by improving the passive stiffness and the active suspension force.

[0033] Combined with the embodiment of pole pieces with transverse elements, further advantages arise. The end faces can be made significantly wider relative to the circumferential direction, i.e., their extension in the circumferential direction can be significantly greater than that of the end faces of coil cores known from the prior art. Conversely, the distance between the two end faces of two adjacent coil cores can be significantly reduced. This is because the field emerging laterally from the pole pieces flows parallel to the transverse elements stacked in the axial direction and therefore does not generate additional eddy currents.

[0034] According to a preferred embodiment, the end face has at least one groove extending in the axial direction. In other words, this means that the at least one groove can extend in the end face in the axial direction with any length.

[0035] According to a preferred embodiment, at least one slot extends from an axial first end of the pole piece to an axial second end of the pole piece.This extension will therefore be the maximum possible extension of the slot in the end face in the axial direction.

[0036] For possible embodiments in which an end face has more than one slot, it is possible that one slot extends axially from a first end of the pole piece, and a second slot extends in the opposite axial direction from the second axial end of the pole piece to the first slot. In this case, it is possible that the two slots each have an axial extension that is less than 50% of the axial extension of the end face. In other words, this means that the end face has two slots that do not touch in the middle of the end face, and therefore there is at least one transverse element of the pole piece that is not captured by the slot.

[0037] At least one slot is provided in the end face of the coil core to provide electrical insulation. This means that the at least one slot ensures that the path of eddy currents in the transverse element of the pole piece is interrupted and thus blocked. Eddy currents caused by the magnetic field emerging from the transverse element in the axial direction can thus be prevented. As a result, only small eddy currents remain in the coil core, and the eddy current losses in the coil core are greatly reduced overall. Advantageously, the at least one slot should extend parallel or at least approximately parallel to the course of the magnetic field in the transverse element of the pole piece so as not to block the magnetic field.

[0038] Many different methods can be used to produce the grooves. These methods include, in particular, mechanical processes such as milling, punching or cutting, wherein the latter also include the use of lasers and / or water jet cutters and / or wire erosion.

[0039] Furthermore, it is preferred that the radial extension of the at least one slot is smaller than the radial extension of the pole piece. In a preferred embodiment, the radial extension of the at least one slot is in the region of 5-30% of the radial extension of the pole piece. It is also possible for the extension to be more than 30% of the pole piece extension, for example 40%, 50%, or even 99%. A greater radial extension of the at least one slot is possible, in particular in designs in which the at least one slot does not extend through all transverse elements of the pole piece. In this case, even 100% is conceivable.

[0040] According to a preferred embodiment, several grooves are arranged parallel or at least approximately parallel to each other in the end face.In an advantageous embodiment, several grooves are arranged perpendicular to the end face.

[0041] An arrangement of several slots parallel to one another is advantageous, since this means that they also extend parallel or at least approximately parallel to the course of the magnetic field in the coil core, so that they do not block the magnetic field.

[0042] According to a preferred embodiment, each coil core has a rounding at the axial upper end, which redirects the coil core from the axial direction into the radial direction.

[0043] For example, in the case of an L-shaped coil core, in which the long part of the "L" is formed by the longitudinal legs and the short part of the "L" is formed by the pole pieces, the radially outer edges of the pole pieces, which extend in the radial plane in the circumferential direction when viewed from the cup-shaped recess, are designed to be rounded. This embodiment has the advantage that it has lower eddy current losses and is also easier to implement with regard to construction. This embodiment can be implemented with all possible embodiments of the end faces and the pole pieces or longitudinal legs.

[0044] According to a preferred embodiment, each coil core has a first lateral boundary surface and a second lateral boundary surface, wherein at least one of the first lateral boundary surface or the second lateral boundary surface has at least one slot. Providing a slot in at least one of the two lateral boundary surfaces of the coil core provides electrical insulation. This means that the at least one slot ensures that the path of eddy currents in the coil core is interrupted and thus blocked. As a result, only small eddy currents remain in the coil core, and the eddy current losses in the coil core are greatly reduced overall. In this case, it is advantageous if the at least one slot should extend parallel or at least approximately parallel to the path of the magnetic field in the coil core so as not to block the magnetic field.

[0045] How far the at least one groove extends in the longitudinal leg in the axial direction in the direction of the first end of the longitudinal leg can vary. All lengths of the at least one groove are possible, from a minimum extension in the axial direction of 5% of the total length of the longitudinal leg to an extension towards the first end of the longitudinal leg.

[0046] It is also possible that at least one groove has a rounding which redirects the groove from a radial direction into an axial direction.

[0047] An embodiment is also possible in which at least one groove extends from the first lateral boundary surface to the second lateral boundary surface.

[0048] In other embodiments, it is possible that the extension of at least one slot is shorter than the distance between the first and second lateral boundary surfaces, when viewed in the circumferential direction of the stator.

[0049] In other words, the at least one slot does not extend through the entire coil core in the circumferential direction of the stator. This means that the at least one slot is not provided in all longitudinal elements of the sheet metal design of the coil core. This is advantageous because the majority of eddy currents occur particularly in longitudinal elements that are arranged directly on or close to the two lateral boundary surfaces. Therefore, the path of eddy currents in the coil core is interrupted by the at least one slot, where eddy currents occur most frequently. This ensures a significant reduction in eddy current losses. Furthermore, this embodiment contributes to the stability of the coil core.

[0050] Embodiments in which several slots arranged parallel to one another are provided are also possible. Here, the arrangement of several slots parallel to one another is advantageous because they therefore also extend parallel or at least approximately parallel to the course of the magnetic field in the coil core so that they do not block the magnetic field.

[0051] Many different methods can be used to produce the grooves. These methods include, in particular, mechanical processes such as milling, punching or cutting, the latter also including the use of lasers or water jet cutters.

[0052] According to a particularly preferred embodiment, a back iron is arranged at the first end, which back iron connects the first ends of all longitudinal legs, wherein the back iron is designed in an annular manner with a metal strip which extends from a radially inner starting point to a radially outer end, wherein the strip forms several strip windings lying against one another with respect to the radial direction.

[0053] According to a particularly preferred embodiment, the stator of the magnetic levitation device is designed to generate a torque, with which the rotor can be driven magnetically in a contactless manner for rotation about an axial direction.

[0054] Here, the stator is designed as a bearing and drive stator, which is both an electrically driven stator and a magnetically suspended stator. The stator's electrical windings can be used to generate a magnetic rotating field. This magnetic rotating field, on the one hand, exerts a torque on the rotor, which causes the rotor to rotate about the desired axis of rotation. On the other hand, this magnetic rotating field exerts a arbitrarily adjustable transverse force on the rotor, so that the radial position of the rotor can be actively controlled or adjusted.

[0055] Especially with regard to embodiments in which the magnetic levitation device is designed to generate torque, embodiments with wider end faces are advantageous, since this facilitates the magnetic function. For example, increased torque can be generated, or the passive stiffness or active levitation force can be improved.

[0056] Furthermore, the present invention proposes an electromagnetic rotary drive designed as a temple-shaped motor, wherein the electromagnetic rotary drive comprises a magnetic levitation device according to the invention and a rotor having a disk-shaped or annular magnetically active core, wherein the rotor can be inserted into the cup-shaped recess, and wherein the rotor is designed as a rotor of the electromagnetic rotary drive.

[0057] Such electromagnetic rotary drives are also referred to as bearingless motors. The term bearingless motor refers to electromagnetic rotary drives in which the rotor is completely magnetically suspended relative to the stator, without separate magnetic bearings being provided.

[0058] Further advantageous measures and embodiments of the invention are evident from the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] In the following, the invention will be explained in more detail with reference to embodiments and with reference to the accompanying drawings, in which:

[0060] Figure 1 : A perspective view of a first embodiment of a magnetic levitation device according to the present invention,

[0061] Figure 2 :From Figure 1 A perspective view of a single coil core of a magnetic levitation device,

[0062] Figure 3 :From Figure 2 A perspective view of a first variant of a coil core,

[0063] Figure 4 :From Figure 3 An enlarged view of the pole piece of the coil core,

[0064] Figure 5 :From Figure 2 A perspective view of a second variant of the coil core,

[0065] Figure 6 : A perspective view of a second embodiment of the magnetic levitation device according to the present invention,

[0066] Figure 7 :From Figure 6 A perspective view of a single coil core of a magnetic levitation device,

[0067] Figure 8 : A perspective view of a third embodiment of a magnetic levitation device according to the present invention, and

[0068] Figure 9 : Schematic cross-sectional view of an embodiment of a stator housing. DETAILED DESCRIPTION

[0069] Figure 1 A perspective view of an embodiment of a magnetic levitation device according to the present invention is shown, which is designated in its entirety by reference numeral 1. The magnetic levitation device 1 is designed for contactless magnetic levitation of a rotor 3 comprising a disk-shaped or annular magnetic active core 31. The magnetic levitation device 1 is designed according to a temple-like configuration and comprises a stator 2. Typically, the stator 2 comprises a stator housing 21 ( Figure 9 ), however, for reasons of better overview, the stator housing 21 is not Figure 1 Therefore, in the schematic cross-sectional view, Figure 9 An embodiment of the stator housing 21 is shown.

[0070] A cup-shaped recess 211 is provided at one axial end of the stator housing 21, into which the rotor 3 can be inserted. The rotor 3 is designed to rotate about a desired rotation axis. The desired rotation axis defines an axial direction A. Typically, the center axis of the stator 2 extending in the axial direction A coincides with the desired rotation axis. The desired rotation axis specifies the axis about which the rotor 3 rotates in an operating state when the rotor 3 is in a centered and non-tilted position relative to the stator 2, as shown in FIG. Figure 1 Indicated.

[0071] The stator 2 has a plurality of coil cores 25 (here, six coil cores 25), each of which has a longitudinal leg 26 and a pole piece 27. Each longitudinal leg 26 extends from a first end 261 in the axial direction A to a second end 262, with a contact surface 271 disposed at the second end 262. Each pole piece 27 extends from the contact surface 271 at least partially in the radial direction R to an end face 272. The end face 272 faces the rotor 3 and is disposed around the rotor 3. In other words, the pole pieces 27 of the coil cores 25 are arranged such that the end faces 272 of the pole pieces 27 are disposed around the cup-shaped recess 211. The coil cores 25 of the stator 2 are arranged equidistantly on a circular line, so that when the rotor 3 is inserted into the cup-shaped recess 211, the end faces 272 surround the magnetically active core 31 of the rotor 3.

[0072] In this embodiment, the contact surface 271 is designed in a planar manner and is arranged at a surface of the longitudinal leg 26 that is perpendicular to the radial direction R.

[0073] For better understanding, Figure 2 Indicates from Figure 1 1 is a perspective view of a single coil core 25 of a magnetic bearing device 1 .

[0074] At least one concentrated winding 61 is arranged at each longitudinal leg 26, and at least one concentrated winding 61 surrounds the corresponding longitudinal leg 26. In other embodiments, more than one concentrated winding may be arranged at the longitudinal leg 26. For example, there is Figure 1 In the embodiment shown here, exactly two concentrated windings 61a, 61b are provided on each of the longitudinal legs 26, each of the concentrated windings 61a, 61b surrounding the respective longitudinal leg 26, wherein the two windings 61a, 61b arranged on the same longitudinal leg 26 are arranged adjacent to one another with respect to the axial direction A.

[0075] The concentrated winding 61 is used to generate an electromagnetic field, by which the rotor 3 can be magnetically suspended in the cup-shaped recess 211 ( Figure 9 )middle.

[0076] exist Figure 1 In the first embodiment of the magnetic levitation device 1 according to the invention represented in , the pole pieces 27 are made of transverse elements 273 in the form of metal sheets, and these transverse elements 273 are stacked in the axial direction A.

[0077] Due to the transverse elements 273 of the pole pieces 27 stacked in the axial direction, the field flowing in the circumferential direction is conducted parallel to the metal plate plane. In this way, eddy current losses are greatly reduced.

[0078] This creates another important advantage. The end faces 272 of the pole pieces 27 can be arranged much closer to each other in the circumferential direction because the field flowing from the pole piece 27 of the first coil core 25 to the pole piece 27 of the adjacent second coil core 25 in the circumferential direction does not generate any additional eddy current losses. Therefore, for example, the passive stiffness and active suspension force can be improved and / or a more compact design of the stator is possible. Several possible connection methods can be used to perform the attachment of the pole piece 27 to the longitudinal leg 26. In particular, these methods include force locking connection methods (such as clamping or crimping), shape locking connection methods (such as screwing or plugging) or material locking connection (such as gluing). It is also possible to connect between the longitudinal leg 26 and the pole piece 27 via a tongue and groove joint and / or a plug (such as a pin, a tines or a dovetail joint). In a preferred embodiment, the material locking connection method is achieved by gluing.

[0079] Here, the end surface 272 of the pole piece 27 is designed as a curved surface arranged coaxially with the cup-shaped recess 211. In this case, the end surface 272 is designed to be wider than the maximum extension of the contact surface 271 in the circumferential direction relative to the circumferential direction. The circumferential direction refers to a direction perpendicular to the radial direction R and perpendicular to the axial direction A.

[0080] Therefore, the end face 272 of the pole piece 27 can be considered as a segment of the surface of a cylinder, wherein the central axis of the cylinder coincides with the central axis of the cup-shaped recess 211, which in this embodiment is the axis of the axial direction A, and the radius of the cylinder is greater than the radius of the cup-shaped recess 211, so that the end face 272 does not protrude into the cup-shaped recess 211.

[0081] In other words, this means that one of the two edges 2721 or 2722 of the end surface 272 extending in the circumferential direction is longer than one of the edges 2711 or 2712 of the contact surface extending in the circumferential direction. If the end surface 272 is designed as a curved surface, the length of one of the arcs 2721 or 2722 of the cylindrical surface segment in the radial plane is greater than the length of one of the edges 2711 or 2712 of the contact surface 271 extending in the circumferential direction. Figure 1 , indicated by a line in the radial direction R perpendicular to the axial direction A. A radial plane is a plane perpendicular to the axial direction A and containing the radial direction R. The radial plane is the plane in which the magnetically active core 31 of the rotor 3 is actively magnetically suspended between the end faces 272 in the stator 2 in the operating state. If the rotor 3 is not tilted and is not deflected in the axial direction A, the magnetic center plane lies in the radial plane. The radial plane defines the xy plane of a Cartesian coordinate system, whose z-axis extends in the axial direction A.

[0082] The radial position of the magnetically active core 31 or of the rotor 3 refers to the position of the rotor 3 in a radial plane.

[0083] In this embodiment, the longitudinal legs 26 are also produced from longitudinal elements 263 in the form of sheet metal, wherein the longitudinal elements 263 are stacked in the circumferential direction of the stator 2 .

[0084] The longitudinal elements 263 and the transverse elements 273 can be made of electrical sheet metal. According to a general definition, electrical sheet metal is understood to be a soft magnetic material for the core. There is also the possibility of using mu-metal for the strips.

[0085] The number of longitudinal elements 263 and transverse elements 273 in all embodiments and figures is to be understood as purely exemplary. The number may be greater or even less than the number indicated.

[0086] According to a particularly preferred embodiment, the stator 2 is designed such that, in addition to the contactless magnetic levitation of the rotor 3, the stator 2 can also exert a torque on the rotor 3 or the magnetically active core 31 of the rotor 3, which drives the rotor 3 to rotate about the desired axis of rotation. This means that, in this preferred embodiment, the rotor 3 can be driven for rotation about the axial direction A.

[0087] The aforementioned widening of the end surface 272 in the circumferential direction has the advantage of facilitating the magnetic function. For example, the passive stiffness and the active levitation force can be improved. In embodiments in which the magnetic levitation device 1 is designed to generate torque, there is also the advantage that increased torque can be generated.

[0088] In this embodiment, the concentrated windings 61 a , 61 b ​​therefore generate an electromagnetic rotating field, with which the rotor 3 can be both magnetically levitated relative to the stator 2 and driven for rotation about the axial direction A in a contactless manner.

[0089] It is understood that the number of six coil cores 25, although preferred, is to be understood only as an example. Of course, embodiments are also possible in which the stator 2 has fewer than six (e.g., five, four, or three) coil cores 25, or embodiments are also possible in which the stator 2 has more than six (e.g., seven, eight, or nine) coil cores 25, or any greater number of coil cores 25.

[0090] The rotor 3 comprises a magnetically active core 31 designed in an annular or disk-shaped manner. Figure 1 As shown in FIG, the magnetically effective core 31 is designed as a ring and defines a magnetic center plane. Alternatively, the magnetically effective core 31 can also be designed as a disk. Generally, in the case of a disk-shaped or ring-shaped magnetically effective core 31, the magnetic center plane is the geometric center plane of the magnetically effective core 31 of the rotor 3, perpendicular to the axial direction A. In the operating state, the magnetically effective core 31 is suspended in a radial plane perpendicular to the axial direction A.

[0091] Since this is sufficient for understanding the present invention, Figure 1 Only the magnetically active core 31 of the rotor 3 is shown. It is understood that the rotor 3 may also include further components, such as a jacket or an encapsulation, which is preferably made of plastic, or metal, or a metal alloy, or ceramic or a ceramic material. In addition, the rotor 3 may also include guide vanes or other components for mixing, stirring or pumping the fluid.

[0092] When the rotor 3 is inserted into the cup-shaped recess 211 ( Figure 9 ), the rotor 3 and in particular the magnetically active core 31 of the rotor 3 is surrounded by the radially outwardly arranged end faces 272 of the pole pieces 27 of the coil core 25 of the stator 2. The pole pieces 27 thus form a plurality of distinct stator poles, in this case six stator poles.

[0093] When the magnetically active core 31 of the rotor 3 is in its desired position during operation, it is centered between the end faces 272 of the pole pieces 27. According to this representation, the concentrated windings 61 are arranged below a radial plane and are aligned so that their coil axes extend in the axial direction A.

[0094] All first ends 261 of the longitudinal legs 26 (ie, according to the representation ( Figure 1 ) are connected to each other via a back iron 28. The back iron 28 is preferably designed in an annular manner. Such an embodiment is possible (see for example Figure 1 ), wherein the back iron 28 extends radially inwardly along all first ends 261 of the longitudinal legs 26.

[0095] In order to generate the electromagnetic field required for magnetic levitation of the rotor 3 and optionally for generating a torque on the rotor 3 , the longitudinal legs 26 of the coil core 25 carry a winding designed as a concentrated winding 61 .

[0096] In operation, these concentrated windings 61 generate electromagnetic rotating fields that can exert on the rotor 3 arbitrarily adjustable transverse forces in the radial direction, making it possible to actively control or adjust the radial position of the rotor 3 , i.e., its position in a radial plane perpendicular to the axial direction A. Optionally, these electromagnetic rotating fields can also be used to generate a torque on the rotor 3 .

[0097] The “magnetically active core 31 ” of the rotor 3 refers to the region of the rotor 3 that magnetically cooperates with the stator 2 for generating a magnetic levitation force and optionally for generating a torque.

[0098] As already mentioned, in this embodiment, the magnetically active core 31 is designed in an annular manner. Furthermore, the magnetically active core 31 is designed in a permanent magnetic manner. For this purpose, the magnetically active core 31 may include at least one permanent magnet, but may also include several permanent magnets, or (as in the embodiment described here) may consist entirely of permanent magnetic material, so that the magnetically active core 31 is a permanent magnet. For example, the magnetically active core 31 is magnetized in the radial direction.

[0099] Ferromagnetic or ferrimagnetic materials that are magnetically hard, i.e., have a high coercive field strength, are typically referred to as permanent magnets. The coercive field strength is the magnetic field strength required to demagnetize the material. Within the scope of this application, a permanent magnet is understood to be a component or material that has a coercive field strength, more precisely, a coercive field strength of the magnetic polarization, that is greater than 10,000 A / m.

[0100] An embodiment is also possible in which the magnetically active core 31 is designed without permanent magnets, i.e., without permanent magnets. The rotor 3 is then designed, for example, as a reluctance rotor. The magnetically active core 31 of the rotor 3 is then made, for example, of a soft magnetic material. Suitable soft magnetic materials for the magnetically active core 31 are, for example, ferromagnetic or ferrimagnetic materials, i.e., in particular iron, nickel iron, cobalt iron, silicon iron, or mu metal.

[0101] Furthermore, embodiments are possible in which the magnetically active core 31 of the rotor 3 comprises both ferromagnetic and permanent magnet materials. For example, permanent magnets may be placed or inserted into a ferromagnetic matrix. Such an embodiment is advantageous, for example, if one wishes to reduce the cost of a large rotor by conserving permanent magnet material.

[0102] Embodiments are also possible in which the rotor is designed according to the principle of a cage rotor.

[0103] The stator 2 has no permanent magnets. Within the framework of the present application, the term stator 2 is designed “without permanent magnets” to be understood as meaning that the stator 2 does not include any permanent magnets that contribute substantially to the drive field for driving the rotation of the rotor 3 or for generating the magnetic levitation force of the rotor 3. Therefore, the magnetic flux generated by the stator 2 for driving and levitation of the rotor 3 does not include any flux of permanent magnet excitation.

[0104] Of course, it is possible that the rotor 3 and / or the stator 2 include other magnets or permanent magnets, for example in sensors used for example to capture the angular position of the rotor or otherwise to achieve purposes unrelated to generating magnetic flux for driving and levitation of the rotor 3 .

[0105] Therefore, the term "without permanent magnets" refers only to the magnetic flux generated by the stator 2 for driving and levitating the rotor 3. In other words, the stator 2 has no permanent magnets contributing to the magnetic flux by means of which the rotor 3 is driven and magnetically levitated.

[0106] However, it is still possible that the magnetic flux used for the drive and levitation of the rotor 3 comprises permanent magnetic flux, but this is then only generated by the rotor 3 itself. This would be the case if the rotor 3 itself were to comprise permanent magnets.

[0107] The annular back iron 28 can be made of a soft magnetic material, since this is very suitable for conducting magnetic flux. It is also possible that the coil core 25 of the stator 2 is also made of a soft magnetic material.

[0108] Suitable soft magnetic materials for the coil core 25 and the back iron 28 are, for example, ferromagnetic or ferrimagnetic materials, i.e. in particular iron, nickel iron, cobalt iron, silicon iron or mu metal. In this case, a design as a stator sheet metal stack is preferred for the stator 2, wherein the back iron 28 is designed as sheet metal, i.e. it consists of several thin sheet metal elements (also called back iron elements 283), which are stacked parallel to each other in the axial direction A. All back iron elements 283 are designed identically, i.e. in this case are essentially annular and also have the same thickness in each case. Therefore, the back iron 28 itself is designed essentially in an annular manner and, in the assembled state, extends radially inwards along the first end 261 of the longitudinal leg 26.

[0109] An embodiment is also possible in which a so-called tape-wound annular core is used as the back iron 28. This is the coiled strip 29. Figure 8 Such a design is implemented in the third embodiment shown in FIG.

[0110] Furthermore, it is possible that the back iron 28 consists of pressed and subsequently sintered grains of the aforementioned materials. The metal grains are preferably embedded in a plastic matrix so that they are at least partially insulated from one another, thereby minimizing eddy current losses. Therefore, soft magnetic composite materials consisting of electrically insulating and compressed metal particles are also suitable for the stator. In particular, these soft magnetic composite materials (also designated as SMC (soft magnetic composite)) can consist of iron powder particles coated with an electrically insulating layer. These SMCs are then formed into the desired shape using a powder metallurgy process.

[0111] During operation of the magnetic levitation device 1, the magnetically active core 31 of the rotor 3 cooperates with the stator 2 so that the rotor 3 can be magnetically levitated contactlessly relative to the stator 2 and, preferably, can also be magnetically set to rotate contactlessly about the axial direction A. In this case, it is particularly advantageous if the same windings 61 used to achieve the magnetic levitation of the rotor 3 are also used to generate torque on the rotor 3. Preferably, three degrees of freedom of the rotor 3 can then be actively adjusted: its position in the radial plane and its rotation. With respect to its axial deflection in the axial direction A from the radial plane, the magnetically active core 31 of the rotor 3 is passively magnetically stabilized by magnetic resistance, meaning it cannot be controlled. The magnetically active core 31 of the rotor 3 is also passively magnetically stabilized with respect to the remaining two degrees of freedom: tilt relative to a radial plane perpendicular to the desired axis of rotation. Through the cooperation of the magnetically active core 31 with the coil core 25, the rotor 3 is thus passively magnetically levitated or passively magnetically stabilized against tilt in the axial direction A (a total of three degrees of freedom), and actively magnetically levitated in the radial plane (two degrees of freedom).

[0112] As is generally the case, active magnetic suspension is also referred to in the present application as magnetic suspension that can be actively controlled or adjusted, for example, by means of an electromagnetic field generated by concentrated windings 61. Passive magnetic suspension or passive magnetic stabilization is magnetic suspension or magnetic stabilization that cannot be controlled or adjusted. Passive magnetic suspension or stabilization is based, for example, on a reluctance force that returns the rotor 3 to its desired position when it is deflected from its desired position, i.e., when it is displaced or deflected in the axial direction A or when it is tilted.

[0113] In the magnetic levitation device 1, in contrast to classical magnetic bearings, the magnetic levitation and optionally the generation of a torque acting on the rotor are achieved by means of an electromagnetic rotating field. In order to combine the generation of a magnetic levitation force and a torque for rotating the rotor 3 about the axial direction A, it is possible, on the one hand, to Figure 7 As shown in FIG, exactly one concentrated winding 61 is arranged on each longitudinal leg 26 .

[0114] On the other hand, an embodiment is also possible in which two different winding systems are provided for the combined generation of the magnetic levitation force and the torque for rotating the rotor 3. For this purpose, for example, Figure 1 As represented in , at each longitudinal leg, exactly two concentrated windings 61 a , 61 b ​​are arranged in each case, which are arranged adjacent to one another with respect to the axial direction A. One of the two windings 61 a , 61 b ​​belongs to a first winding system of the two winding systems, and the other belongs to a second winding system of the two winding systems.

[0115] exist Figure 8In the exemplary embodiment shown in FIG. 1 , in which there is precisely one concentrated winding 61 per coil core 25, the current values ​​required for levitation and the current values ​​required for torque generation, determined in each case in the control unit, are added or superimposed by calculation (e.g., using software). The resulting total current is then applied to the corresponding concentrated winding 61.

[0116] If the stator 2 of the magnetic levitation device 1 according to the present invention is designed to generate torque, the magnetic levitation device 1 is suitable for an electromagnetic rotary drive designed as a temple motor. It is also possible that the magnetic levitation device 1 according to the present invention is also suitable for other devices, such as centrifugal pumps, mixing devices for mixing flowable substances, stirring devices for mixing fluids in tanks, for example, fans, or devices for supporting and rotating wafers, for example, in semiconductor production.

[0117] Figure 3 Shown from Figure 2 A perspective view of a first variant of the coil core 25. One difference from the first variant is that the end face 272 has at least one slot 2724, wherein the at least one slot 2724 extends from the axial first end 274 of the pole piece 27 to the axial second end 275 of the pole piece 27. For a better understanding, Figure 4 Indicates from Figure 3 FIG. 2 is an enlarged view of the pole piece 27 of the coil core 25 .

[0118] At least one slot 2724 is provided in the end face 272 of the coil core 25 to provide electrical insulation. This means that the at least one slot 2724 ensures that the path of eddy currents in the transverse element 273 of the pole piece 27 is interrupted and thus blocked. As a result, only small eddy currents remain in the coil core 25, and the eddy current losses in the coil core 25 are significantly reduced overall. Advantageously, the at least one slot 2724 should extend parallel or at least approximately parallel to the path of the magnetic field in the transverse element 273 of the pole piece 27 so as not to block the magnetic field.

[0119] Many different methods can be used to produce the grooves 2724. In particular, these methods include mechanical processes such as milling, punching or cutting, the latter also including the use of lasers and / or water jet cutters and / or wire erosion.

[0120] In this variant of the coil core 25, several slots 2724 (here, five slots 2724) are arranged parallel to one another in the end face 272. The number of slots 2724 in all embodiments and figures is to be understood purely as an example. This number may be greater or less than the number indicated. It is also possible that the slots 2724 may only be approximately parallel to one another, such as being inclined or curved toward one another. What is important here is that they follow the field path of the magnetic flux. This depends, in particular, on the outer shape of the pole piece 27 or the transverse element 273.

[0121] In this embodiment, the extension T of the slot 2724 in the radial direction R is smaller than the extension L of the pole piece 27 in the radial direction R.

[0122] In a preferred variant, the extension T of the at least one slot 2724 in the radial direction R is in the region of 5-30% of the extension L of the pole piece 272 in the radial direction R. It is also possible that the extension T has more than 30%, for example 40% or 50% or even 99%, of the extension L of the pole piece 27 .

[0123] For the embodiment of the coil core 25 shown here, in which the end face 272 is designed as a curved surface, it is applicable that the extension T is determined individually for each individual slot 2724, since the length L is different at each point on the edge 2722 due to the curvature. For this reason, the slots 2724 in this variant of the coil core 25 have different extensions T compared to one another.

[0124] Variants of the coil core 25 are also possible in which the slots 2724 all have the same extension T. This can be the case for coil cores 25 with curved end faces 272 as well as for coil cores 25 with non-curved end faces 272, as in Figure 2 Of course, it is also possible that, in the case of a non-curved end face 272, the slot 2724 can have a different extension T.

[0125] Figure 5 Shown from Figure 2 In the following description of the second variant of the coil core, only the components from Figure 3 The differences from the first variant of 1 / 4 are shown. The explanations of the first variant also apply in the same way or analogously to the second variant. The same reference numerals designate the same features or functionally equivalent features as explained with reference to the first variant.

[0126] A second variant of coil core 25 has slots 2724 in end face 272 that extend in axial direction A but do not extend through all transverse elements 273. A first number of slots 2724 extends from a first axial end 274 of pole piece 27 in axial direction A, and a second number of slots 2724 extends from a second axial end 275 of pole piece 27 in an axial direction A opposite to the first number of slots 2724. In this case, the amount of each extension TA of all slots 2724 in axial direction A is less than 50% of the extension SA of end face 272 in axial direction A. In other words, end face 272 has a first number of slots 2724 starting at first axial end 274 and a second number of slots 2724 starting at second axial end 275, such that the first number of slots 2724 and the second number of slots 2724 do not touch each other at axial center AM of end face 272, and therefore at least one transverse element 273 of pole piece 27 is not captured by a slot 2724.

[0127] In this variant, it is possible for the extension T of the at least one slot 2724 in the radial direction to be even equal to the extension L of the pole piece 27 in the radial direction R. Figure 6 A perspective view of a second embodiment of the magnetic levitation device 1 according to the present invention is shown. For a better understanding, Figure 7 Indicates from Figure 6 In the following description of the second embodiment of the magnetic levitation device 1, only the coil core 25 from FIG. Figure 1 The explanations of the first embodiment also apply in the same way or analogously to the second embodiment. The same reference numerals designate the same features or functionally equivalent features as explained with reference to the first embodiment.

[0128] One difference is that each coil core 25 has a rounding 257 at the upper axial end 252 , which redirects the coil core from the axial direction A to the radial direction R.

[0129] For example, in the case of an L-shaped coil core 25, wherein the long portion of the "L" is formed by the longitudinal legs 26 and the short portion of the "L" is formed by the pole piece 27, when viewed from the cup-shaped recess 211, the radially outer locating edge 258 ( Figure 1-Figure 3 ) is designed in a rounded manner. This embodiment has the following advantages: it has lower eddy current losses and is also easier to implement in terms of construction. This embodiment can be implemented with all possible embodiments of the end face 272 and the pole piece 27 or the longitudinal leg 26.

[0130] Each coil core 25 has a first lateral boundary surface 255 and a second lateral boundary surface 256, wherein at least one of the first lateral boundary surface 255 or the second lateral boundary surface 256 has at least one slot 254. In this embodiment, three slots 254 are arranged in each of the first lateral boundary surface 255 and the second lateral boundary surface 256. The slots 254 extend in the longitudinal leg 26. The provision of the slots 254 in the two lateral boundary surfaces 255, 256 of the coil core 25 provides electrical insulation. This means that the slots 254 ensure that the path of the eddy currents in the coil core 25 is interrupted and thus blocked. As a result, only small eddy currents remain in the coil core 25, and the eddy current losses in the coil core 25 are greatly reduced overall.

[0131] In this embodiment, each of the slots 254 has a rounded portion 2541 that redirects the corresponding slot 254 from the radial direction R to the axial direction A. The slots 254 are arranged parallel to one another and parallel or at least approximately parallel to the course of the magnetic field in the coil core 25. This has the advantage that the slots 254 therefore do not hinder and / or block the course of the magnetic field in the coil core 25.

[0132] In this embodiment, the extension of the slot 254 is shorter than the distance between the first lateral boundary surface 255 and the second lateral boundary surface 256 when viewed in the circumferential direction of the stator 2. In other words, the slot 254 does not penetrate all longitudinal elements 263 of the coil core 25, but only penetrates a certain number of longitudinal elements 263.

[0133] This is advantageous because the majority of eddy currents occur particularly in longitudinal elements 263, which are arranged directly on or close to the two lateral boundary surfaces 255, 256. Consequently, the path of eddy currents in coil core 25 is interrupted by slots 254, where eddy currents occur most frequently. This ensures a significant reduction in eddy current losses. Furthermore, the fact that slots 254 do not completely penetrate all longitudinal elements 263 of coil core 25 contributes to the stability of coil core 25.

[0134] However, embodiments are also possible in which the groove 254 extends from the first lateral boundary surface 255 to the second lateral boundary surface 256 .

[0135] In this embodiment, the slot 254 does not extend over the entire extension of the longitudinal leg 26 in the axial direction A, but only partially and ends before the axially upper end of the concentrated winding 61 a.

[0136] In addition, however, at least one of the slots 254 has a length in the longitudinal leg 26 that is longer than Figure 7 Extended embodiments of the embodiments shown in are also possible. Such possible embodiments are Figure 8Indicated in.

[0137] Figure 8 A perspective view of a third embodiment of a magnetic levitation device 1 according to the invention is shown. In the following description of the third embodiment of the magnetic levitation device 1, only the components from FIG. Figure 1 and Figure 6 The differences between the first and second embodiments are shown in FIG. 1 . The explanations of the first and second embodiments also apply in the same manner or analogously to the third embodiment. The same reference numerals designate the same features or functionally equivalent features as explained with reference to the first embodiment.

[0138] As already mentioned, one difference of the third embodiment is the extension of the slot 254 in the longitudinal leg 26. This is significantly longer than the extension of the slot 254 of the coil core 25 from the second embodiment. The maximum possible extension of the slot 254 in the longitudinal leg 26 ends at the first end 261 of the longitudinal leg 26. It is therefore possible for the slot 254 to have any extension length in the longitudinal leg 26.

[0139] This embodiment of the magnetic levitation device 1 is similar to the embodiment of the magnetic levitation device 1 from Figure 1 and Figure 6 Another difference in the embodiment of the present invention lies in the different design of the back iron 28. The back iron 28 is designed in an annular manner, comprising a metal strip 29 extending from a radially inner starting point 291 to a radially outer end 292. The strip 29 forms a plurality of strip windings 293, which lie flat against one another relative to the radial direction R. The longitudinal leg 26 is bounded at its first end 261 by an axial end face 265, against which the back iron 28 rests. The back iron 28 forms a circular ring whose radial width is equal to the radial width of the end face 265 of the longitudinal leg 26. This means that the radially inner starting point 291 is flush with the inner surface 266 of the longitudinal leg 26, located radially inwardly, in the axial direction A, and the radially outer end 292 is flush with the outer surface 267 of the longitudinal leg 26, located radially outwardly, in the axial direction A.

[0140] In particular, this has the advantage that there is more space inside the stator 2, which can be used to install other components therein. In doing so, the stator 2 together with the stator housing can be made smaller and more compact, which increases the flexibility of use of the magnetic levitation device 1.

[0141] A further advantage of such an arrangement of the back iron 28 results from the arrangement of the strip windings 293 with the strips 29 wound around the annular core. Due to the fact that the strip windings 293 are arranged perpendicular to the radial direction R, they have an orientation parallel to the magnetic field course in the longitudinal legs 26. As a result, the magnetic field from the longitudinal legs 26 enters the back iron 28 in the axial direction A and therefore parallel to the strip windings 293. This means that the magnetic field does not penetrate any of the strip windings 293 in the radial direction R, thereby avoiding eddy current losses.

[0142] As already mentioned, here too, in the third exemplary embodiment, only one concentrated winding 61 is arranged in each case on each longitudinal leg 26 .

[0143] It goes without saying that all embodiments shown in the description of the figures with their corresponding features can be combined with one another in any way.

[0144] Furthermore, it is possible that all of the illustrated exemplary embodiments of the coil core 25 can be designed such that the space available for the rotor 3 in the magnetic levitation device 1 is increased. This is achieved by the special outer shape of the coil core 25 .

[0145] During this process, the coil core 25 is divided into an axially lower section and an axially upper section, wherein the lower section and the upper section are arranged adjacent to each other relative to the axial direction A. Pole pieces 27 are arranged in the axially upper section. For each coil core 25, the end face 272 of the pole piece 27 has a first radial distance from the axially lower section of the associated longitudinal leg 26, and a second radial distance from the axially upper section, wherein the second distance is greater than the first distance. This means that each longitudinal leg 26 is designed such that the axially upper section is displaced radially outward relative to the axially lower section, thereby increasing the space available for the rotor 3 between the end faces 272 without risking direct magnetic flux transfer between the longitudinal legs 26 and the magnetically active core 31 of the rotor 3. Due to the fact that the axially upper section is offset radially outward relative to the radial direction and relative to the axially lower section, the distance between the longitudinal leg 26 and the end face 272 (i.e., the second distance) increases in the region of the axially upper section. In doing so, the distance between the magnetically active core 31 of the rotor and the longitudinal legs 26 , in particular in the region of the axially upper section, is also increased.

[0146] The coil core 25 just described is designed similarly to that in European patent application EP 4 084 304 A1. Figure 3 Those coil cores shown in FIG.

[0147] Figure 9 A schematic cross-sectional view of an embodiment of a stator housing 21 is shown. Figure 1 、 Figure 6 and Figure 8 In the embodiment shown in FIG, the stator housing 21 is not shown for reasons of better overview. Figure 9 It is intended merely to serve as a diagram showing the encapsulated appearance of the interior of the stator 2 necessary for the operation of the magnetic levitation device 1. For this reason, the other components of the stator 2 are only represented schematically and are to be understood as purely illustrative.

[0148] An embodiment of the stator housing 21 is also possible in which the cup-shaped recess 211 merges into a bore which extends centrally in the axial direction A along the center axis of the stator 2 through the entire stator housing 21 .

[0149] During operation of the magnetic levitation device 1 in a field where, for example, chemically aggressive substances are used, it is important that the interior of the stator 2 is securely encapsulated and thus protected from the effects of these substances. To ensure that the rotor 3 can still be used, the stator housing 21 has a cup-shaped recess 211 into which the rotor 3 can be inserted.

Claims

1. A magnetic levitation device for contactless magnetic levitation of a rotor (3) having a disk-shaped or annular magnetically active core (31), wherein: The magnetic levitation device has a stator (2), the stator (2) has a cup-shaped recess (211), the cup-shaped recess (211) is arranged at an axial end of the stator (2) and the rotor (3) can be inserted into the cup-shaped recess (211), wherein the stator (2) has a plurality of coil cores (25), each of the plurality of coil cores (25) has a longitudinal leg (26) and a pole piece (27), wherein each longitudinal leg (26) extends from a first end (261) to a second end (262) in an axial direction (A), wherein wherein a contact surface (271) is arranged at the second end portion (262), wherein each pole piece (27) extends from the contact surface (271) at least partially in a radial direction (R) to an end face (272), wherein the radial direction (R) is perpendicular to the axial direction (A), wherein the end face (272) is arranged around the cup-shaped recess (211), and wherein at least one concentrated winding (61) is arranged at each longitudinal leg (26), the at least one concentrated winding (61) surrounding the respective longitudinal leg (26), It is characterized by: Each pole piece (27) is made of a transverse element (273) in the form of a metal sheet, wherein the transverse elements (273) are stacked in the axial direction (A).

2. The magnetic levitation device according to claim 1, wherein: Each longitudinal leg (26) is made of a longitudinal element (263) in the form of a metal sheet, wherein the longitudinal elements (263) are stacked in the circumferential direction of the stator (2).

3. A magnetic levitation device according to any one of the preceding claims, wherein: The transverse elements (273) and / or the longitudinal elements (263) are made of electrical metal sheets.

4. A magnetic levitation device according to any one of the preceding claims, wherein: The contact surface (271) is designed in a planar manner and is arranged on a surface of the longitudinal leg (26) perpendicular to the radial direction (R).

5. A magnetic levitation device according to any one of the preceding claims, wherein: The end surface (272) of the pole piece (27) is designed as a curved surface, and the end surface (272) is designed and arranged to be coaxial with the cup-shaped recess (211).

6. A magnetic levitation device according to any one of the preceding claims, wherein: The end surface (272) is designed to be wider with respect to the circumferential direction than the maximum extension of the contact surface (271) in the circumferential direction.

7. A magnetic levitation device according to any one of the preceding claims, wherein: The end surface (272) has at least one groove (2724) extending in the axial direction A.

8. The magnetic levitation device according to claim 7, wherein: The at least one slot (2724) extends from an axial first end (274) of the pole piece (27) to an axial second end (275) of the pole piece (27).

9. The magnetic levitation device according to claim 7-8, wherein: An extension (T) of the at least one slot (2724) in the radial direction (R) is shorter than an extension (L) of the pole piece (27) in the radial direction (R).

10. The magnetic levitation device according to claims 7-9, wherein: Several grooves (2724) are arranged parallel or at least approximately parallel to each other in the end surface (272).

11. A magnetic levitation device according to any one of the preceding claims, wherein: Each coil core (25) has a rounding (257) at an axially upper end (252), which redirects the coil core from the axial direction (A) to the radial direction (R).

12. A magnetic levitation device according to any one of the preceding claims, wherein: Each coil core (25) has a first lateral boundary surface (255) and a second lateral boundary surface (256), and wherein at least one of the first lateral boundary surface (255) or the second lateral boundary surface (256) has at least one slot (254).

13. A magnetic levitation device according to any one of the preceding claims, wherein: A back iron (28) is arranged at the first end (261), the back iron (28) connecting the first ends (261) of all longitudinal legs (26), wherein the back iron (28) is designed in an annular manner with a metal strip (29), which extends from a radially inner starting point (291) to a radially outer end (292), wherein the strip (29) forms several strip windings (293) lying against each other with respect to the radial direction (R).

14. A magnetic levitation device according to any one of the preceding claims, wherein: The stator (2) is designed to generate a torque with which the rotor (3) can be driven magnetically without contact for rotation about the axial direction (A).

15. Electromagnetic rotary drive designed as a temple motor, characterized in that The electromagnetic rotary drive comprises a magnetic levitation device (1) according to claim 14 and a rotor (3) having a disk-shaped or annular magnetically active core (31), wherein the rotor (3) can be inserted into the cup-shaped recess (211) and wherein the rotor (3) is designed as the rotor (3) of the electromagnetic rotary drive.

Images