MAGNETIC BEARING DEVICE

Description

[0001] The invention relates to a magnetic bearing device according to the preamble of the independent patent claim.

[0002] Magnetic bearing devices for the contactless magnetic support of a rotor have the advantage of eliminating the need for mechanical bearings. The rotor is supported and stabilized by magnetic forces generated by a stator within the magnetic bearing device. Due to the absence of mechanical bearings, such magnetic bearing devices are particularly suitable for pumps, mixers, centrifuges, or stirrers used to handle highly sensitive substances, such as blood pumps, or where very high purity requirements apply, for example, in the pharmaceutical or biotechnology industries. They are also suitable for handling abrasive or aggressive substances that would quickly destroy mechanical bearings, such as pumps or mixers for slurries, sulfuric acid, phosphoric acid, or other chemicals in the semiconductor industry.

[0003] In In the biotechnology industry, such magnetic bearing devices are used, for example, in connection with bioreactors, e.g., in centrifugal pumps for conveying fluids into or out of the bioreactor, or in mixing devices that mix the fluids in the bioreactor. In In the semiconductor industry, such magnetic bearing devices are used not only for conveying aggressive or abrasive substances, but also, for example, for rotary devices used to rotate wafers.

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

[0005] An advantageous and known embodiment of a magnetic bearing device is the temple-style design, to which the present invention also relates.

[0006] The characteristic feature of the temple design is that the stator of the magnetic bearing device has a plurality of coil cores, each comprising a longitudinal leg extending from a first end in an axial direction to a second end. The axial direction here refers to the direction defined by the nominal axis of rotation of the rotor, which is supported by the magnetic bearing device. The nominal axis of rotation is the axis around which the rotor rotates in the operating state when it is in a centered and untilted position relative to the stator. In addition to the longitudinal leg, each coil core comprises a transverse leg, which is located at the second end of the longitudinal leg and extends radially—usually inwards—with the radial direction being perpendicular to the axial direction. The transverse leg thus extends essentially at right angles to the longitudinal leg.The coil cores are each L-shaped, with the crossbars forming the shorter legs of the L. The rotor to be supported is then positioned between the crossbars.

[0007] The majority of the longitudinal legs, which extend in an axial direction and resemble the columns of a temple, gave this construction method its name.

[0008] In one embodiment, the stator of the magnetic bearing device 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 circumferentially by a return path, which serves to guide the magnetic flux. The rotor to be supported comprises a magnetically active core, for example, a permanent magnet disk or a permanent magnet ring, which is arranged between the radially inner ends of the transverse legs and rotates about the axial direction during operation, with the rotor being magnetically supported without contact with the stator.

[0009] For such magnetic bearing devices, it is not necessarily the case that the magnetically effective core of the rotor must be made of permanent magnets. Designs are also known in which the magnetically effective core of the rotor is free of permanent magnets, i.e., without permanent magnets. In such cases, the magnetically effective core of the rotor is, for example, made of ferromagnetic material such as iron, nickel-iron, cobalt-iron, silicon-iron, mu-metal, or another ferromagnetic material.

[0010] Furthermore, designs are possible in which the magnetically active core of the rotor comprises both ferromagnetic and permanent magnet materials. For example, permanent magnets can be embedded or inserted into a ferromagnetic base body. Such designs are advantageous, for instance, when one wants to reduce costs in large rotors by saving on permanent magnet material.

[0011] To generate the electromagnetic fields necessary for the contactless magnetic suspension of the rotor, the longitudinal legs carry windings. These windings are designed, for example, such that a concentrated winding is wound around each longitudinal leg, meaning that the coil axis of each concentrated winding extends in the axial direction. It is typical of the temple design that the coil axes of the concentrated windings run in the axial direction and that the concentrated windings are not arranged in the radial plane in which the rotor, or the magnetically active core of the rotor, is supported during operation.

[0012] Configurations are possible in which exactly one concentrated winding is arranged on each longitudinal leg. In other configurations, several concentrated windings, for example exactly two, are provided on each longitudinal leg. Configurations are also possible in which windings are provided that are wound around two circumferentially adjacent longitudinal legs, such that these two adjacent longitudinal legs are both located inside the concentrated winding. The magnetic bearing device typically includes a control unit, which contains the power electronics for controlling and supplying the stator windings, such as power converters or inverters for providing the current to be applied to the windings, or circuit breakers for controlling the windings.With a view to achieving the most compact design and the lowest possible complexity of the magnetic bearing device, attempts have already been made to position the control unit as close as possible to the stator. However, this results in significant thermal problems, because the control unit in particular generates large amounts of heat during operation, which are difficult to dissipate.

[0013] In the control unit, it is primarily the power electronics, such as the power switches for controlling the windings, that generate a significant amount of heat during operation. Therefore, if the motor unit and the control unit are located close to each other, there is a risk that the heat generated during operation cannot be dissipated sufficiently, which can lead to overheating of the electronic components and thus significantly reduce their lifespan.

[0014] A generic magnetic storage device is disclosed in EP 4 084 304 A1.

[0015] Based on this state of the art, it is therefore an object of the invention to propose a magnetic bearing device for the contactless magnetic bearing of a rotor with a ring- or disc-shaped magnetically effective core, which has a particularly compact design, wherein the control unit is reliably protected against overheating.

[0016] The subject matter of the invention that solves this problem is characterized by the features of the independent patent claim.

[0017] According to the invention, a magnetic bearing device is proposed for the contactless magnetic mounting of a rotor comprising a disk-shaped or ring-shaped magnetically active core, wherein the magnetic bearing device comprises a housing, a stator, and a control device. The stator comprises a plurality of coil cores, each of which has a longitudinal leg extending from a first end in an axial direction to a second end, and a transverse leg arranged at the second end of the longitudinal leg and extending in a radial direction perpendicular to the axial direction, wherein at least one concentrated winding is provided on each longitudinal leg, surrounding the respective longitudinal leg, wherein the stator further comprises a cup-shaped recess into which the rotor can be inserted, the cup-shaped recess being arranged at an axial end of the stator.The control unit comprises a circuit board with a front and a back, the front of which houses circuit breakers for controlling the windings. The housing comprises an outer wall, a stator housing for the stator, a control housing for the control unit, and a partition separating the stator housing from the control housing. At least one rib is arranged on the partition and adjacent to the outer wall, projecting into the control housing. The back of the circuit board rests on this rib, and a plurality of circuit breakers are arranged in the area of ​​the circuit board where the back of the board rests on the rib. Thermal connectors for heat dissipation are provided between the plurality of circuit breakers and the rib.

[0018] This specific arrangement of the circuit breakers, in combination with the thermal connectors, allows for particularly efficient dissipation of the heat generated by the circuit breakers via the thermal connections, the at least one web, and the partition into the outer wall of the housing. From there, the heat is then released to the environment, for example, via convection. This efficient heat dissipation reliably protects the electronic components of the control unit from overheating. Since the circuit breakers for driving the windings are typically one of, if not the main, heat sources in the control unit, reliable heat dissipation is essential for the longevity and operational reliability of the magnetic bearing device.

[0019] Since the control unit and the stator are both arranged in the housing of the magnetic bearing device, the magnetic bearing device according to the invention is characterized by a very compact and space-saving design.

[0020] The thermal interface elements are preferably designed as through-holes, also known as thermal vias. A thermal via is typically a hole that extends from the front of the circuit board, through the board, to the back. The heat generated by the electronic components located on the front of the board can be dissipated via the thermal vias to the back of the board, where it is then absorbed by a heat sink.

[0021] Power switches are the electronic components that control and energize the stator windings. They typically comprise transistors, preferably MOSFETs, which form half-bridges or full-bridges that drive the stator windings. Typically, one or more of these half-bridge or full-bridge circuits are housed in a power switch chip package, which may optionally also include drivers. The power switch chip package is then attached to the front of the circuit board using a die attach paddle (DAP). The power switch chip package has several connection pins through which the electronic components, such as the transistors, can be electrically connected to traces or terminals on the circuit board.The chip packages are attached to the circuit board using adhesive or a soldered connection, for example.

[0022] In In a preferred embodiment of the magnetic bearing device, the outer wall of the housing, the partition, and the web are designed as a single, integral unit. This enables a particularly compact design and efficient heat dissipation via the housing.

[0023] Preferably, each circuit breaker is arranged on a separate mounting surface, each mounting surface being connected to the back of the circuit board via a plurality of thermal connecting elements, and each thermal connecting element extending from the front to the back of the circuit board. These mounting surfaces on the front of the circuit board are preferably designed as cooling surfaces, in particular as metallic cooling surfaces, each of which is preferably thermally connected to the back of the circuit board via a plurality of thermal vias.

[0024] A preferred measure is to provide additional thermal connectors, each extending from the front to the back of the circuit board, with each additional thermal connector located outside the separate mounting areas. The thermal connectors thus also include those located not under the mounting areas for the circuit breakers, but in other areas of the circuit board. This allows targeted heat dissipation from those areas of the front of the circuit board where no circuit breakers are located.

[0025] Another preferred measure is to provide a contact pad on the back of the circuit board for each mounting surface. This pad thermally couples all thermal connectors belonging to that mounting surface. This means that all thermal connectors belonging to the same mounting surface terminate on the contact pad on the back of the circuit board, thus thermally coupling all these thermal connectors together. These contact pads further improve the thermal connection to the housing of the magnetic bearing device because they transfer heat to the housing over a large area.

[0026] Furthermore, it is a preferred measure to arrange a thermal conductivity layer between the bridge and the back of the circuit board, with which heat can be transferred from the circuit board to the housing.

[0027] The thermal interface is preferably designed as a film attached to the back of the circuit board. The film consists of a thermally conductive material. This film can be mounted or soldered to the back of the circuit board. The thermal interface is able to transfer heat over a wide area to the housing, thus reducing the thermal resistance.

[0028] Each thermally conductive layer designed as a film is preferably made of a thermally conductive and easily deformable, in particular ductile, material, so that the films can compensate for small irregularities and mechanical tolerances.

[0029] The thermal conductivity layer is preferably made of a metallic material, such as copper or silver. Each thermal conductivity layer is designed, for example, as a copper foil. Copper foils have the advantage of being easy to solder. To further improve solderability, the copper foils can also be coated with a precious metal (such as gold).

[0030] Another option is to use a coating for the thermally conductive layer. Coatings containing a high proportion of metal particles are preferred. These coatings are then applied to the contact surfaces to create the thermally conductive layer. The resulting thermally conductive layer is also relatively easy to deform and enables very good thermal contact.

[0031] According to a preferred embodiment, the control housing of the enclosure is designed with an interior having a substantially rectangular or square cross-sectional area perpendicular to the axial direction. This is preferred because the control housing is thereby particularly well suited to accommodating the preferably rectangular or square circuit board of the control device. A rectangular or square circuit board is significantly simpler to manufacture than, for example, a round one.

[0032] Furthermore, it is preferred that the stator housing of the enclosure is designed with an interior having a substantially circular cross-sectional area perpendicular to the axial direction A. This is preferred because the stator housing is thereby particularly well suited to accommodating the coil cores of the stator, which are preferably arranged on a circular path.

[0033] In In a preferred embodiment, a housing cover is arranged at one axial end of the magnetic bearing device, which closes the control housing. The housing cover is particularly preferably designed to hermetically seal the control housing.

[0034] Furthermore, it is preferred that the stator comprises a split pot which forms an axial end of the stator, wherein the split pot has the cup-shaped recess. In The cup-shaped recess of the splitting pot can then be used to insert the rotor to be stored.

[0035] Preferably, the partition comprises an inner cup, which is essentially cylindrical and is arranged radially inside the interior space surrounded by the windings. The inner cup is advantageous for better dissipating the heat generated in the stator during operation, e.g., the heat generated by copper and iron losses.

[0036] The housing comprises the stator housing and the control housing, which are preferably arranged adjacent to each other with respect to the axial direction, wherein the stator housing is designed to accommodate the coil cores with the concentrated windings arranged thereon, and the control housing is designed to accommodate the control unit for controlling and supplying the windings with electrical energy to generate electromagnetic fields.

[0037] Preferably, the housing is designed such that the coil cores with the concentrated windings arranged thereon can be inserted axially into the stator housing in a first installation direction, and the control unit can be inserted into the control housing in a second installation direction, the first installation direction being opposite to the second installation direction. The housing preferably has two separate sections, one forming the stator housing and the other the control housing. These two sections are separated by a partition wall. The partition wall has openings, e.g., for electrical connections. The housing is preferably designed as a single piece with respect to its circumference.

[0038] According to a particularly preferred embodiment, the stator is designed to generate a torque with which the rotor can be magnetically driven to rotate around the axial direction without contact.

[0039] Further advantageous measures and embodiments of the invention will be found in the dependent claims.

[0040] The invention will now be explained in more detail with reference to exemplary embodiments and the drawing. The drawing shows: Fig. 1: a sectional view of an embodiment of a magnetic bearing device according to the invention, Fig. 2: a perspective view of the embodiment from Fig. 1 in an exploded view, Fig. 3: a perspective view of the stator and the holding device, Fig. 4: a perspective exploded view of the coil cores, the windings and the holding device, Fig. 5: a sectional view of the stator's containment shell, Fig. 6: a perspective view of the control housing and the circuit board of the control device, Fig. 7: a schematic representation of thermal connecting elements, Fig. 8: a top view of the control housing, Fig. 9: a top view of the back of an exemplary embodiment of a circuit board, Fig. 10: a top view of the front of an exemplary embodiment of a circuit board, Fig. 11: a top view of the back of a variant for the circuit board, Fig. 12: a schematic sectional view of the circuit board made of Fig. 11 , and Fig. 13: a perspective view of a heat-conducting layer.

[0041] Fig. 1 Figure 1 shows a sectional view of an embodiment of a magnetic bearing device according to the invention, which is collectively designated by reference numeral 1. The magnetic bearing device 1 is designed for the contactless magnetic mounting of a rotor 3, which comprises a disk-shaped or ring-shaped magnetically active core 31.

[0042] For better understanding, shows Fig. 2 Another perspective view of the exemplary embodiment from Fig. 1 in a perspective exploded view, wherein in Fig. 2 The rotor 3 is not shown. The magnetic bearing device 1 is designed according to the temple construction method and comprises a stator 2, which has a plurality of coil cores 25 – here six coil cores 25 – each of which comprises a longitudinal leg 26 extending from a first end 261 in an axial direction A to a second end 262, and a transverse leg 27 arranged perpendicular to the longitudinal leg 26, which extends in a radial direction perpendicular to the axial direction A. Each transverse leg 27 is bounded with respect to the radial direction by an end face 271, which forms the pole of the associated coil core 25.

[0043] Each longitudinal leg 26 has at least one, in this embodiment exactly one, concentrated winding 61 provided, which encloses the respective longitudinal leg 26.

[0044] The magnetic bearing device 1 comprises a housing 10 in which the coil cores 25 are arranged.

[0045] For better understanding, the Fig. 3 und Fig. 4 Further representations of the stator 2 of the embodiment of the magnetic bearing device 1, wherein the housing 10 is not shown. Fig. 3 Figure 1 shows a perspective view of the stator 2 and a holding device 9 for the coil cores 25. Furthermore, in Fig. 3 a conclusion 22 is shown, which includes all first ends 261 of the longitudinal legs 26 - i.e., those shown according to the representation ( Fig. 1 ) lower ends 261 - connect to each other and serve to guide the magnetic flux. The return 22 is preferably designed in a ring shape. Fig. 4 shows a perspective exploded view of the coil cores 25 with the concentrated windings 61 arranged on them and the holding device 9.

[0046] The housing 10 is preferably made of a metallic material, for example, aluminum or stainless steel. For improved chemical resistance, the housing 10 can be coated, preferably with a plastic coating made of a highly chemically resistant plastic. Examples of such plastics are PTFE (polytetrafluoroethylene), PFA (perfluoroalkoxy polymers), ECTFE (ethylene chlorotrifluoroethylene), ETFE (ethylene tetrafluoroethylene), epoxy resin (polyepoxide), PPA (polyphthalamide), and PE (polyethylene). Depending on the intended application, the housing 10 can also be made of titanium or chromium steel.

[0047] The stator 2 further comprises a split pot 21 with a cup-shaped recess 211 (see also Fig. 5 ), into which the rotor 3 to be stored can be inserted (see Fig. 1 The containment pot 21 forms one of the two axial ends of the stator 2 or the magnetic bearing device 1, as shown in the illustration in Fig. 1 the upper axial end of the stator 2. At the other axial end of the magnetic bearing device 1, a housing cover 11 is arranged, which closes the housing 10.

[0048] The containment pot 21 is firmly connected to the housing 10, for example by means of a positive-locking connection and / or by means of an elastic seal 201. Preferably, the containment pot 21 is hermetically sealed to the housing 10. The housing cover 11 is firmly connected to the housing 10, for example by means of screws 111 ( Fig. 1 ), wherein a sealing element 105 is optionally arranged between the housing cover 11 and the housing 10. The sealing element 105 can in particular be designed as a flat gasket. Preferably, the housing cover 11 is hermetically sealed to the housing 10.

[0049] Preferably, the housing 10, together with the containment shell 21 and the housing cover 11, forms a hermetically sealed housing in which the other components of the stator 2 are hermetically encapsulated. The housing 10 is preferably filled with a thermally conductive potting compound, for example, an epoxy resin, so that the components arranged inside the housing 10 are surrounded by the potting compound. This reduces the overall thermal resistance and dampens vibrations.

[0050] The housing cover 11 is preferably made of a plastic. Particularly for applications in chemically aggressive environments, a chemically resistant plastic such as polypropylene is preferred.

[0051] The transverse legs 27 of the coil cores 25 are arranged in the split pot 21 such that the end faces 271 of the transverse legs 27 are arranged around the cup-shaped recess 211.

[0052] The coil cores 25 of the stator 2 are arranged equidistantly on a circular line, such that the end faces 271 surround the magnetically active core 31 of the rotor 3 when the rotor 3 is inserted into the cup-shaped recess 211. Exactly one concentrated winding 61 is provided on each longitudinal leg 26, surrounding the longitudinal leg 26.

[0053] In other embodiments, more than one concentrated winding can be arranged on the longitudinal legs 26. For example, there are embodiments in which exactly two concentrated windings are provided on each of the longitudinal legs 26, each of which surrounds the respective longitudinal leg 26, with the two windings arranged on the same longitudinal leg 26 being adjacent to each other with respect to the axial direction A.

[0054] The concentrated windings 61 serve to generate electromagnetic fields with which the rotor 3 can be magnetically stored without contact in the cup-shaped recess 211 of the cracked pot 21.

[0055] Furthermore, a control unit 40 is provided for controlling and supplying the windings 61 with electrical energy. The control unit 40 includes, in particular, the power electronics that feed the required currents into the windings 61. The control unit 40 is in Fig. 1 and in Fig. 2 as shown. In particular, the control unit 40 is also preferably arranged inside the housing 10, for example as shown ( Fig. 1 ) below the first ends 261 of the longitudinal legs 26 of the coil cores 25. The control unit 40 is optionally also encapsulated with a thermal potting compound or coupled to the housing 10 and the return 22 and / or the coil cores 25 of the stator 2. The control unit 40 comprises a circuit board 41 on which various electronic components 42 are arranged.

[0056] As is particularly evident in the Fig. 1 and Fig. 2 As can be seen, the housing 10 preferably comprises two separate areas arranged adjacent to each other with respect to the axial direction A, one of which forms a stator housing 101 and the other a control housing 102. The stator housing 101 of the housing 10 is designed to receive the coil cores 25 with the windings 61 arranged thereon, and the control housing 102 is designed to receive the control unit 40. The stator housing 101 and the control housing 102 are separated from each other by a partition 103, wherein the partition 103 has passages or openings 104 (see e.g. Fig. 6 ) are provided through which connecting lines, for example electrical connections from the control housing 102 to the stator housing 101, can be passed.

[0057] According to a preferred embodiment, the partition 103 comprises an inner cup 13, which is substantially cylindrical and is arranged radially inside the interior space surrounded by the windings 61. The inner cup 13 is connected to an outer wall 15 of the housing 10 via a flange-like projection 14 of the partition 103. The outer wall 15 forms the radially outer boundary of the housing 10. Particularly preferably, the partition 103, which comprises the inner cup 13 and the flange-like projection 14, is an integral part of the housing 10. The outer wall 15 and the partition 103 are formed as a single piece and constitute the preferably one-piece housing 10.

[0058] The partition 103 with the inner cup 13 and the flange-like projection 14 separates the area of ​​the housing 10, which forms the stator housing 101, from the area which forms the control housing 102.

[0059] The inner cup 13 of the partition 103, connected to the flange-like projection 14, extends from the radially inner edge of the flange-like projection 14 in axial direction A and is arranged radially inside the windings 61 and the return 22 in the interior space surrounded by the windings 61, as shown in particular in Fig. 1 This can be seen. With respect to the radial direction, the inner cup 13 is located adjacent to the longitudinal legs 26 of the coil cores 25 and the windings 61 arranged thereon, so that the inner cup 13 can absorb and dissipate the heat generated by the windings 61 and the coil cores 25 particularly well. With respect to the axial direction A, the inner cup 13 extends approximately to the cup-shaped recess 211 of the containment shell 21.

[0060] As is particularly evident in Fig. 2 As can be seen, the stator housing 101 of the housing 10 is designed with an interior having a substantially circular or annular cross-sectional area perpendicular to the axial direction A. This is preferred because the stator housing 101 can thereby accommodate the annular return 22 with the coil cores 25 arranged around the return 22 particularly well. The control housing 102 of the housing 10 is designed with an interior having a substantially rectangular or square cross-sectional area perpendicular to the axial direction A. This is preferred because the control housing 102 is thereby particularly well suited to accommodating the preferably rectangular or square circuit board 41 of the control device 40. A rectangular or square design of the circuit board 41 is considerably simpler to manufacture than, for example, a round design.

[0061] Due to this design of the stator housing 101 and the control housing 102, the axial end of the stator 2, at which the containment shell 21 closes the housing 10, has a substantially round cross-section, so that the containment shell 21 has a round or annular shape. In contrast, the axial end of the stator 2, at which the housing cover 11 closes the housing 10, has a substantially rectangular or square cross-section, so that the housing cover 11 has a rectangular or square shape.

[0062] Exemplary in character are in Fig. 1 Some components of the control unit 40 are shown. The control unit 40 includes, for example, the circuit board 41, on which the electronic components 42 are provided, e.g., the power electronics for controlling the windings 61. This will be explained in more detail later. The circuit board 41 can also contain, for example, evaluation electronics for evaluating the signals from sensors, e.g., magnetic field sensors, and serve as a communication interface. The circuit board 41 is preferably designed as an electronic circuit board or PCB (printed circuit board). Furthermore, a connecting cable 45 is provided, which is connected to the circuit board 41 via a cable connector (not shown) or a plug. The connecting cable 45 leads out of the housing 10 and serves, for example, to supply power to the magnetic bearing device 1. The connecting cable 45 is led out of the housing 10 by means of a sealing cable gland 47.Preferably, the cable entry 47 is designed to be hermetically sealed.

[0063] The circuit board 41 of the control unit 40 is connected to the windings 61 via connecting lines (not shown), for example cables, in order to control and supply them with energy. For this purpose, the feedthroughs or openings 104 are provided in the partition 103 ( Fig. 8 ) provided, through which the connecting lines are routed. Such feedthroughs can be arranged, for example, in the flange-like projection 14 or in the inner cup 13.

[0064] The circuit board 41 is preferably arranged on the flange-like projection 14, as will be explained in more detail later. This makes it possible to dissipate the heat generated in the control unit 40 via the housing 10 in a particularly efficient manner.

[0065] The interior of the inner cup 13, i.e., the space enclosed by the inner cup 13, can be used for further electronic components, electronic boards, or connectors or connections. These are in Fig. 1 Not shown for the sake of clarity.

[0066] According to a particularly preferred embodiment, the stator 2 is configured such that, in addition to the contactless magnetic bearing of the rotor 3, it 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 a predetermined axis of rotation. The predetermined 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 relative to the stator 2, as is the case in Fig. 1 This desired axis of rotation extends in the axial direction A, meaning that, in this preferred embodiment, the rotor 3 arranged in the containment shell 21 of the stator 2 can be driven to rotate about the axial direction A. Typically, the desired axis of rotation coincides with the central axis of the stator 2, which extends in the axial direction A.

[0067] In this configuration, the concentrated windings 61 generate electromagnetic rotating fields with which the rotor 3 can be magnetically mounted without contact with respect to the stator 2 and can also be driven to rotate without contact in the axial direction A.

[0068] It is understood that the number of six coil cores 25 is preferred, but only exemplary. Of course, configurations are also possible in which the stator 2 has fewer than six, e.g., five, four, or three coil cores 25, or configurations in which the stator 2 has more than six, e.g., seven, eight, or nine coil cores 25, or any larger number of coil cores 25.

[0069] The rotor 3 comprises the magnetically active core 31, which is designed in a ring or disc shape. The magnetically active core 31 is as shown in the illustration in Fig. 1 The magnetically active core 31 is designed as a ring and defines a magnetic center plane. Alternatively, the magnetically active core 31 can also be designed as a disk. Typically, in the case of a disk-shaped or ring-shaped magnetically active core 31, the magnetic center plane is the geometric center plane of the magnetically active core 31 of the rotor 3, which lies perpendicular to the axial direction A. In the operating state, the magnetically active core 31 is mounted in a radial plane E, which is perpendicular to the axial direction A. The radial plane is in Fig. 1 indicated by line E, which is perpendicular to the axial direction A. The radial plane E is therefore the plane which is perpendicular to the axial direction A and contains line E.

[0070] The radial plane E is the plane in which the magnetically active core 31 of the rotor 3 is magnetically supported between the end faces 271 in the stator 2 during operation. If the rotor 3 is neither tilted nor deflected in the axial direction A, the magnetic center plane lies in the radial plane E. The radial plane E defines the xy-plane of a Cartesian coordinate system whose z-axis runs in the axial direction A.

[0071] 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 E.

[0072] Since it is sufficient for understanding the invention, the drawing in the Fig. 1 Only the magnetically active core 31 of the rotor 3 is shown. It is understood that the rotor 3 can, of course, also include further components such as casings or encapsulations, preferably made of a plastic, or of a metal or metal alloy, or of a ceramic or ceramic material. Furthermore, the rotor 3 can also include vanes for mixing, stirring, or pumping fluids, or other components.

[0073] When the rotor 3 is inserted into the cup-shaped recess 211 of the containment pot 21, the rotor 3, and in particular the magnetically active core 31 of the rotor 3, is surrounded by the radially outwardly arranged end faces 271 of the transverse legs 27 of the coil cores 25 of the stator 2. The transverse legs 27 thus form a plurality of pronounced stator poles—here, six stator poles. The transverse legs 27 are arranged at the upper ends of the longitudinal legs 26 and in the radial plane E. Each transverse leg 27 extends radially toward the rotor 3.

[0074] When the magnetically active core 31 of the rotor 3 is in its intended position during operation, it is centered between the end faces 271 of the transverse legs 27, such that the transverse legs 27, which are arranged in the radial plane E, also lie in the magnetic center plane. The concentrated windings 61 are arranged below the radial plane E and oriented such that their coil axes run in the axial direction A.

[0075] All first ends 261 of the longitudinal legs 26 - i.e., those shown in the illustration ( Fig. 1 ) lower ends 261 - are through inference 22 (see also Fig. 3 ) connected to each other. The return 22 is preferably designed in a ring shape. Such configurations are possible (see e.g. Fig. 1 ), in which the inference 22 extends radially inwards along all first ends 261 of the longitudinal legs 26.

[0076] In order to generate the electromagnetic fields necessary for the magnetic bearing of the rotor 3 and optionally for generating a torque on the rotor 3, the longitudinal legs 26 of the coil cores 25 carry the windings designed as concentrated windings 61.

[0077] With these concentrated windings 61, those electromagnetic rotating fields are generated in the operating state with which an arbitrarily adjustable transverse force in the radial direction can be exerted 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, is E, It is actively controllable or adjustable. Optionally, these electromagnetic rotating fields are also used to exert a torque on rotor 3.

[0078] The "magnetically effective core 31" of the rotor 3 refers to the area of ​​the rotor 3 which magnetically interacts with the stator 2 for the generation of magnetic bearing forces and optionally for torque generation.

[0079] As already mentioned, the magnetically effective core 31 in this embodiment is ring-shaped. Furthermore, the magnetically effective core 31 is a permanent magnet. For this purpose, the magnetically effective core 31 can comprise at least one permanent magnet, but also several permanent magnets, or – as in the embodiment described here – consist entirely of a permanent magnetic material, so that the magnetically effective core 31 is the permanent magnet. The magnetically effective core 31 is, for example, magnetized in the radial direction.

[0080] It is also possible to configure the rotor 3 in such a way that the magnetically effective core 31 is free of permanent magnets. The rotor 3 is then, for example, designed as a reluctance rotor. The magnetically effective core 31 of the rotor 3 then consists, for example, of a soft magnetic material. Suitable soft magnetic materials for the magnetically effective core 31 are, for example, ferromagnetic or ferrimagnetic materials, in particular iron, nickel-iron, cobalt-iron, silicon-iron, and mu-metal.

[0081] Furthermore, configurations are possible in which the magnetically active core 31 of the rotor 3 comprises both ferromagnetic and permanent magnet materials. For example, permanent magnets can be inserted or embedded in a ferromagnetic base body. Such configurations are advantageous, for example, when one wants to reduce costs in large rotors by saving on permanent magnet material.

[0082] It is also possible to design the rotor according to the principle of a squirrel cage rotor.

[0083] Both the annular return 22 and the coil cores 25 of the stator 2 are each made of a soft magnetic material because they serve as flux guide elements to guide the magnetic flux.

[0084] Suitable soft magnetic materials for the coil cores 25 and the return 22 are, for example, ferromagnetic or ferrimagnetic materials, in particular iron, nickel-iron, cobalt-iron, silicon-iron, or mu-metal. For the stator 2, a stator lamination stack configuration is preferred, in which the coil cores 25 and the return 22 are laminated, i.e., they consist of several thin lamination elements stacked together.

[0085] Furthermore, it is possible that the coil cores 25 and the return 22 consist of pressed and subsequently sintered grains of the aforementioned materials. The metallic grains are preferably embedded in a polymer matrix so that they are at least partially insulated from each other, thereby minimizing eddy current losses. Soft magnetic composite materials, consisting of electrically insulated and compressed metal particles, are also suitable for the stator. In particular, these soft magnetic composites, also known as SMC (Soft Magnetic Composites), can consist of iron powder particles coated with an electrically insulating layer. These SMCs are then formed into the desired configuration using powder metallurgy processes.

[0086] During operation of the magnetic bearing device 1, the magnetically active core 31 of the rotor 3 interacts with the stator 2 such that the rotor 3 can be magnetically supported without contact with the stator 2, and preferably can also be set into magnetic rotation about the axial direction A without contact. It is particularly advantageous that the same windings 61 used to provide the magnetic support of the rotor 3 also serve to generate a torque on the rotor 3. Preferably, three degrees of freedom of the rotor 3, namely its position in the radial plane E and its rotation, are actively controllable. With respect to its axial displacement from the radial plane E 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 relative to the radial plane E perpendicular to the nominal axis of rotation, the magnetically effective core 31 of the rotor 3 is also passively magnetically stabilized. Thus, the rotor 3 is passively magnetically supported in the axial direction A and against tilting (a total of three degrees of freedom) or passively magnetically stabilized and actively magnetically supported in the radial plane (two degrees of freedom) by the interaction of the magnetically effective core 31 with the coil cores 25.

[0087] 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 electromagnetic fields generated by the concentrated windings 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 target position when it is deflected from its intended position, i.e., when it is displaced or deflected in the axial direction A or tilted.

[0088] In contrast to conventional magnetic bearings, the magnetic bearing device 1 achieves magnetic support – and optionally the generation of a torque acting on the rotor – via rotating electromagnetic fields. To generate the magnetic bearing forces and a torque for rotating the rotor 3 about the axial direction A in the combined manner, it is possible – as in Fig 1 shown, to arrange exactly one concentrated winding 61 on each longitudinal leg 26.

[0089] On the other hand, configurations are also possible in which two different winding systems are provided for the combined generation of the magnetic bearing forces and a torque for rotating the rotor 3. For this purpose, for example, exactly two concentrated windings are arranged on each longitudinal leg, which are adjacent to each other with respect to the axial direction A. One of these two windings belongs to the first of the two winding systems and the other to the second of the two winding systems.

[0090] At the in Fig. 1 In the illustrated embodiment with exactly one concentrated winding 61 on each coil core 25, the values ​​determined in the control unit 40 for the current required for bearing operation and the current required for generating the torque are added or superimposed computationally – e.g., with the aid of software. The resulting total current is then applied to the respective concentrated winding 61.

[0091] In Fig. 3 For better understanding, the return path 22 is shown separately from the coil cores 25. The return path 22 is essentially ring-shaped and extends in the assembled state (see also Fig. 1 ) radially inward along the first ends 261 of the longitudinal legs 26. Preferably, the return 22 is constructed of laminated material. In the laminated design, the return 22 is composed of a plurality of thin elements stacked parallel to each other in the axial direction A. All elements are identical in design, i.e., essentially ring-shaped and of the same thickness.

[0092] The return 22 has a plurality of flats 222 on its radially outer circumferential surface, which are planar, i.e., not curved. In the assembled state of the stator 2, a first end 261 of one of the longitudinal legs 26, which preferably have a rectangular profile, rests against each of these flats 222. The planar design of the flats 222 ensures a large contact area between the return 22 and the longitudinal legs 26 of the coil cores 25, resulting in particularly good magnetic flux guidance and very low magnetic resistance at the interface between the return 22 and the longitudinal legs 26. The flats can also be arranged on separate segments 225, with the separate segments 225 being arranged in grooves of the return 22. The grooves are dimensioned so that the separate segments 225 are flush with the rest of the backing 22.

[0093] Preferably, the number of flattened areas 222 is equal to the number of coil cores 25; here, six flattened areas 222 are provided, which are distributed equidistantly along the outer circumference of the return 22.

[0094] Furthermore, one or more vent holes or recesses 223 may be provided on the return 22, extending completely through the return 22 in the axial direction A. Air can escape through the vent recesses 223, for example, when the housing 20 is filled with a thermally conductive potting compound.

[0095] To determine the current position of the rotor 3 in the cup-shaped recess 211, the magnetic bearing device 1 preferably comprises a plurality of magnetic field sensors (not shown) which, in the assembled state of the magnetic bearing device 1, are arranged around the cup-shaped recess 211. The magnetic field sensors are sensors with which a magnetic field can be measured. With the aid of the magnetic field sensors, the current position of the rotor 3 in the cup-shaped recess 211 of the containment pot 21 or in the radial plane E can be determined in a manner known per se.

[0096] Preferably, the magnetic field sensors are arranged on a sensor board 7 and connected to it via electrical connections, so that all magnetic field sensors can be controlled via the sensor board 7 and the signals measured by the magnetic field sensors can be received and processed via the sensor board 7 or, for example, transmitted to the control device 40.

[0097] The sensor board 7 is arranged with respect to the axial direction A between the windings 61 on one side and the cross legs 27 on the other. The holding device 9 is designed to receive the sensor board 7.

[0098] The sensor board 7 further comprises an electrical connection element 76, which connects the sensor board 7 to the control device 40, so that the control device 40 and the sensor board 7 can exchange electrical voltages or currents via the electrical connection element 76. The electrical connection element 76 is preferably designed as a flexible printed circuit board (FPC). Of course, the electrical connection element 76 can also be designed differently, for example as a cable, a cable bundle, or a ribbon cable.

[0099] Fig. 5 Figure 1 shows a sectional view of the cracked pot 21 of the stator 2 of the embodiment of the magnetic bearing device 1, the section being made in the axial direction A.

[0100] The split cup 21 with the cup-shaped recess 211 is preferably designed as a single piece. The cup-shaped recess has an outer diameter DA such that the rotor 3 to be supported can be inserted into the cup-shaped recess 211. The split cup 21 is preferably made of a plastic, and particularly preferably of a plastic that can be processed by injection molding. The split cup 21 is thus preferably designed as an injection-molded part. Suitable plastics for manufacturing the split cup 21 are, for example, acrylonitrile butadiene styrene (ABS), polyamide (nylon, PA), polypropylene (PP), polytetrafluoroethylene (PTFE), perfluoroalkoxy alkanes (PFA), polyvinyl chloride (PVC), polybutylene terephthalate (PBT), polyimide (PI), polyethereterketone, polysuccinimide (PSI), polyphthalamide (PPA), or polyether ether ketone (PEEK).

[0101] The split pot 21 comprises the cup-shaped recess 211, into which the rotor 3 can be inserted, and a radially outer rim 212, which in the assembled state encompasses the axial rim region 92 of the holding device 9.

[0102] The holding device 9 is essentially plate-shaped and ring-shaped, and includes several recesses 91 ( Fig. 4 ) for receiving the cross legs 27 of the coil cores 25. Exactly one recess 91 is provided for each cross leg 27, so that the number of recesses 91 is equal to the number of coil cores 25. The holding device 9 is inserted into the containment pot 21 (see Fig. 1 ) and extends from the bottom of the split pot 21 in axial direction A to a point as shown in the illustration ( Fig. 1 ) lower edge, which is arranged above the windings 61 with respect to the axial direction A as shown in the illustration.

[0103] The holding device 9 is designed in such a ring shape that it can be arranged around the cup-shaped recess 211 of the split pot 21, so that the cup-shaped recess 211 is enclosed radially on the outside by the holding device 9.

[0104] The holding device 9 is preferably made of a plastic, and particularly preferably of a plastic that can be processed by injection molding. The holding device 9 is therefore preferably designed as an injection-molded part. Suitable plastics for manufacturing the holding device 9 are, for example, acrylonitrile butadiene styrene (ABS), polyamide (nylon, PA), polypropylene (PP), or fiber-filled polypropylene.

[0105] The holding device 9 serves both as a holder for the sensor board 7 with the magnetic field sensors and as a guide and holder for the coil cores 25.

[0106] Fig. 6 Figure 1 shows a perspective view of the control housing 102 and the circuit board 41 of the control unit 40. The circuit board 41 has a front side 411 and a back side 412. The electronic components 42, which are necessary for controlling and supplying the windings 61 with electrical energy, are arranged on the front side of the circuit board 41 of the control unit 40. These are, in particular, circuit breakers 420 (see also Fig. 10 ) for controlling the windings 61, which switch the current supplied to the windings 61. The electronic components 42 further include control and regulation components for monitoring the contactless magnetic bearing and, optionally, the contactless magnetic drive, which are known per se and therefore will not be described in detail here.

[0107] The power switches 420 typically comprise transistors, preferably MOSFETs, with which half-bridges or full-bridges are implemented, which drive the windings 61 of the stator 2. Typically, one or more such half-bridge or full-bridge circuits are contained in a chip package 424 ( Fig. 7 The power switch 420 is arranged in the chip package 424, optionally also including drivers. The chip package 424 of the power switch 420 is then attached to the front side 411 of the circuit board 41 by means of a so-called die attach paddle (DAP). Several connection pins (not shown) are provided on the chip package 424 of the power switch 420, via which the electronic components of the power switch 420, for example the transistors, can be electrically connected to conductor tracks or electrical connections on the circuit board 41. The chip packages 424 of the power switch 420 are attached to the circuit board 41, for example by means of adhesive or by means of a soldered connection.

[0108] For better understanding, shows Fig. 8 a view of the control housing 102. Fig. 9 shows a top view of the back side 412 of circuit board 41, and Fig. 10 shows a top view of the front side 411 of circuit board 41.

[0109] As is particularly evident in the Fig. 6 and Fig. 8 As can be clearly seen, several webs 8 are provided on the partition 103, which delimits the control housing 102, and adjacent to the outer wall 15 of the housing 10, projecting into the control housing 102. Preferably, the webs 8 are an integral part of the partition 103 and the outer wall 15. Particularly preferably, the housing 10, and in particular the outer wall 15, the partition 103, and the webs 8 form a structural unit, which is preferably made of a metallic material, for example, aluminum or stainless steel.

[0110] The webs 8 are arranged where the partition 103 abuts the outer wall 15. The webs 8 serve to support the circuit board 41. The circuit board 41 is placed with its back side 412 onto the webs 8 and fastened to the webs 8, for example with a plurality of screws which pass through screw holes 82 ( Fig. 9 ) reach through the circuit board 41 and engage in threaded holes 81 which are arranged on the webs 8.

[0111] The ribs 8 thus serve as a support on which the back side 412 of the circuit board 41 rests. "Support" or "resting" is therefore to be understood as meaning that the ribs 8 support the circuit board 41, but this does not imply that the back side 412 of the circuit board 41 must be in direct physical contact with the ribs 8. Of course, embodiments are possible in which the back side 412 is in direct physical contact with the ribs 8. However, it is also possible in which the ribs 8 are only partially or not at all in direct physical contact with the back side of the circuit board 41, because, for example, contact pads 87 or thermally conductive layers 88 can be arranged between the back side 412 of the circuit board 41 and the ribs 8. This is illustrated, for example, in the embodiments in Fig. 10 und Fig. 11 shown. The areas with which the back side 412 of the circuit board 41 rests on the bridges 8 are therefore those areas which, viewed in axial direction A, overlap the bridges 8, whereby it is possible but by no means necessary that these areas are wholly or partially in direct physical contact with the bridges 8.

[0112] As is particularly evident in Fig. 10 As can be seen, a majority of the circuit breakers 420 are arranged in the area on the front side 411 of the circuit board 41 where the back side 412 of the circuit board 41 rests on the webs 8. Preferably, all circuit breakers 420 are arranged in the area on the circuit board 41 where the back side 412 of the circuit board 41 rests on the webs 8. Furthermore, thermal connecting elements 85 are provided for each circuit breaker 420 ( Fig. 7 ) provided, which thermally connect the circuit breaker 420 to the bridge 8 on which the area of ​​the circuit board 41 rests on which the respective circuit breaker 420 is arranged.

[0113] Each thermal connection element 85 is preferably designed as a through-hole. These through-holes are also commonly referred to as thermal vias. They form thermal bridges that extend from the front 411 of the circuit board 41 to the back 412 of the circuit board 41.

[0114] Preferably, a plurality of thermal connecting elements 85 are provided for each circuit breaker 420. This is illustrated in the schematic diagram in Fig. 7. Fig. 7 The right-hand illustration shows a section of the back side 412 of the circuit board 41, specifically the area where one of the circuit breakers 420 is located on the front side 411. A total of sixteen thermal connectors 85 are provided, each designed as a via, which thermally connects the circuit breaker 420 to the back side 412 of the circuit board 41 and thus to the web 8 on which this area of ​​the circuit board 41 rests. The sixteen thermal connectors 85 are arranged in four rows of four thermal connectors 85 each. It should be understood that the number of sixteen thermal connectors 85 per circuit breaker is exemplary. Naturally, a larger or smaller number than sixteen thermal connectors 85 per circuit breaker 420 can also be provided.

[0115] The left-hand representation in Fig. 7 Figure 1 schematically shows a cross-section through circuit board 41 with one of the circuit breakers 420 arranged on the front side 411 of circuit board 41. Preferably, a separate mounting surface 421 is provided for each circuit breaker 420 on the front side 411 of circuit board 41, on which the respective circuit breaker 420 is attached, for example by means of a soldered connection. The mounting surface 421 preferably consists of a thermally conductive material, for example a metallic material.

[0116] The power switches 420 typically comprise transistors, preferably MOSFETs, with which half-bridges or full-bridges are implemented that drive the windings 61 of the stator 2. Typically, one or more such half-bridge or full-bridge circuits are arranged in the chip package 424 of the power switch 420, optionally also including drivers in the chip package 424. The chip package 424 of the power switch 420 is mounted on the mounting surface 421 on the front side 411 of the circuit board 41. Several connection pins (not shown) are provided on the chip package 424 of the power switch 420, via which the electronic components of the power switch 420, for example the transistors, can be electrically connected to conductor tracks or electrical connections on the circuit board 41. The electronic components of the circuit breaker 420 are electrically insulated from the chip housing 424.The mounting surface 421, which also serves as a cooling surface for the circuit breaker 420, is normally at earth potential. The thermal connecting elements 85 extend from the mounting surface 421 through the circuit board 41 to the back side 412 of the circuit board 41.

[0117] In operating mode, the circuit breakers 420 constitute one of the main heat sources, if not the main heat source, of the control unit 40. By arranging the circuit breakers 420 in the areas of the circuit board 41 that rest on the webs 8 in the control housing 102, the heat generated by the circuit breakers can be dissipated very efficiently and reliably via the thermal connecting elements 85 into the webs 8 and thus into the housing 10, so that the control unit 40 in particular is reliably protected against overheating.

[0118] As this is in Fig. 9 As can be seen, additional thermal connecting elements 86 are preferably provided, each extending from the front 411 to the back of the circuit board 41. The additional thermal connecting elements 86 are arranged outside the areas where the separate mounting surfaces 421 for the circuit breakers 420 are located. The additional thermal connecting elements 86 serve to selectively dissipate heat from other areas of the front 411 of the circuit board 41 to the back 412 of the circuit board 41. These other areas are those in which no circuit breakers 420 are arranged. The additional thermal connecting elements 86 are also preferably arranged such that they terminate at the webs 8 or are thermally coupled to the webs 8. Each additional thermal connecting element 86 is preferably designed as a through-hole connection.

[0119] Another advantageous measure is to (see Fig. 9 ) that for each mounting surface 421 on the back 412 of the circuit board, a contact pad 87 is provided, which thermally couples all thermal connecting elements 85 belonging to that mounting surface 421. Each contact pad 87 rests on one of the ribs 8. Each contact pad 87 is made of copper, for example. Each contact pad 87 is designed, for example, as a copper foil or as a copper layer, which thermally connects the ends of all thermal connecting elements 85 belonging to the same power switch 420 on the back 412 of the circuit board 41. These large contact pads 87 allow the heat to be dissipated particularly well into the ribs 8 and thus into the housing 10.

[0120] Fig. 11 shows a top view of the back side 412 of a variant for circuit board 41. For better understanding, it shows Fig. 12 a schematic sectional view of this variant of circuit board 41, wherein the section along line XII-XII in Fig. 11 This has been done.

[0121] In this variant, a thermal conducting layer 88 is arranged between the back 412 of the circuit board 41 and the respective bridge 8 on which the circuit board 41 rests, with which heat can be transferred from the circuit board 41 to the respective bridge 8 and thus to the housing 10.

[0122] For better understanding, shows Fig. 13 a perspective view of one of the heat-conducting layers 88.

[0123] Preferably, the shape of the thermal conducting layer 88 corresponds to the surface of the bridge 8 on which the thermal conducting layer 88 rests, so that the entire surface of the bridge 8 on which the circuit board 41 rests is covered by the thermal conducting layer 88.

[0124] The thermal interface layer 88 improves the thermal connection to the housing 10. Preferably, the thermal interface layer 88 is designed as a film made of a thermally conductive material and is arranged between the circuit board 41 and the respective rib 8 on which the circuit board 41 rests. The thermal interface layer 88, designed as a film, can, for example, be mounted or soldered onto the back side 412 of the circuit board 41. It is understood that several thermal interface layers 88 can be provided, so that such a thermal interface layer 88 is arranged between each rib 8 on which the circuit board 41 rests and the circuit board. The thermal interface layers 88 transfer the heat over a broad area to the ribs 8 and thus to the housing 10, thereby reducing the thermal contact resistance.The thermally conductive layers 88, preferably designed as foils, are made of a thermally conductive and easily deformable (ductile) material, enabling them to compensate for minor irregularities and mechanical tolerances. Metallic materials, such as copper or silver, are particularly suitable for the thermally conductive layers 88. Designing the thermally conductive layers 88 as copper foils offers the advantage of easy soldering. To further improve solderability, the copper foils can also be coated with a precious metal, such as gold.

[0125] The following section explains how the magnetic storage device 1 can be assembled in a very simple manner. Assembly can be carried out, for example, as follows: The sensor board 7, with the magnetic field sensors arranged and attached to it, is inserted into the holding device 9.

[0126] The holding device 9 can then be completely filled with a potting compound, such that the sensor board 7 is completely covered by the potting compound.

[0127] The coil cores 25 are guided through the recesses 91 in the holding device 9 and through the concentrated windings 61. The magnetic return 22 is arranged between the first ends 261 of the longitudinal legs 26. The holding device 9, the return 22, and the coil cores 25 with the concentrated windings 61 arranged thereon are installed in a first orientation in axial direction A (as shown in the illustration in Fig. 2 (from the left side) into the stator housing 101 of the housing 10. The electrical connecting element 76 is guided parallel to the longitudinal legs 26 of the coil cores 25 through the stator housing 101 to the control housing 102.

[0128] When the holding devices 9, the windings 61, the return 22 and the coil cores 25 are arranged in the stator housing 101 of the housing 10, the containment pot 21 is placed on the housing 10 and connected to the housing 10 in a sealing, preferably hermetically sealed, manner, with the seal 201 being arranged between the containment pot 21 and the housing 10.

[0129] The housing 10 of the magnetic bearing device 1 is then filled with a thermally conductive potting compound. The potting compound preferably has particularly good thermal conductivity to quickly and reliably dissipate the heat generated during operation into the housing 10, from where the heat is then primarily carried away by convection. Suitable thermally conductive potting compounds include, for example, polyurethanes, epoxy resins, acrylic resins, or polyesters.

[0130] After the stator housing 101 of the housing 10 has been filled with the second potting compound, the control unit 40 is inserted into the control housing 102 of the housing 10 in a second installation direction, the second installation direction being opposite to the first installation direction. As shown in Fig. 2 The control unit 40 is therefore inserted into the control housing 102 from the right. The electrical connecting element 76 is connected to the control unit 40.

[0131] When the control unit 40 is arranged in the control housing 102 of the housing 10, the housing cover 11 is placed on the housing 10 and connected to the housing 10 in a sealing, preferably hermetically, manner, with the sealing element 105 being arranged between the housing cover 11 and the housing 10. The housing cover 11 is, for example, fastened by means of several screws 111 ( Fig. 1 ) attached to housing 10.

[0132] Optionally, the control housing 102 of the housing 10 can also be filled with a potting compound, for example, for applications with highly corrosive, aggressive, or explosive fluids. If the control housing 102 is also filled, this is done before the housing cover 11 is placed on the housing 10 and firmly connected to it.

[0133] The magnetic bearing device 1 according to the invention is particularly suitable for centrifugal pumps, as well as for mixing devices for mixing flowable substances, for stirring devices, for example for mixing a fluid in a tank, for fans or also for devices for carrying and rotating wafers, for example in semiconductor manufacturing.

Claims

1. A magnetic levitation device for contactless magnetic levitation of a rotor (3) comprising a disk-shaped or ring-shaped magnetically effective core (31), wherein the magnetic levitation device comprises a housing (10), a stator (2) and a control device (40), wherein the stator (2) comprises a plurality of coil cores (25), each of which has a longitudinal leg (26) extending from a first end (261) in an axial direction (A) to a second end (262), and a transverse leg (27) which is arranged at the second end (262) of the longitudinal leg, and which extends in a radial direction perpendicular to the axial direction (A), wherein at least one concentrated winding (61) is provided at each longitudinal leg (26), which winding surrounds the respective longitudinal leg (26), wherein the stator (2) further has a cup-shaped recess (211) into which the rotor (3) can be inserted, wherein the cup-shaped recess (211) is arranged at an axial end of the stator (2), wherein the control unit (40) comprises a circuit board (41) with a front side (411) and a back side (412), wherein circuit breakers (420) for controlling the windings (61) are arranged on the front side (411), wherein the housing (10) comprises an outer wall (15), a stator housing (101) for receiving the stator (2), a control housing (102) for receiving the control unit (40), and a separating wall (103) which separates the stator housing (101) from the control housing (102), characterized in that at least one web (8) is arranged on the separating wall (103) and adjacent to the outer wall (15), which web projects into the control housing (102), wherein the back side (412) of the circuit board (41) is supported on the web (8), wherein a plurality of the circuit breakers (420) is arranged in the area of the circuit board (8) with which the back side (412) of the circuit board (41) is supported on the web (8), and wherein thermal connecting elements (85) for dissipating heat are provided between the plurality of circuit breakers (420) and the web (8).

2. The magnetic levitation device according to claim 1, in which the outer wall (15) of the housing (10), the separating wall (103) and the web (8) are designed as a single-piece unit.

3. The magnetic levitation device according to any one of the preceding claims, wherein each circuit breaker (420) is arranged on a respective separate mounting surface (421), wherein each mounting surface (421) is connected to the back side (412) of the circuit board (41) via a plurality of the thermal connecting elements (85), and wherein each thermal connecting element (85) extends from the front side (411) to the back side (412) of the circuit board (41).

4. The magnetic levitation device according to claim 3, wherein additional thermal connecting elements (86) are provided, each of which extends from the front side (411) to the back side (412) of the circuit board (41), wherein each additional thermal connecting element (86) is arranged outside the separate mounting surfaces (421).

5. The magnetic levitation device according to any one of the claims 3 to 4, wherein for each mounting surface (421) a contact pad (87) is provided in each case on the back side (412) of the circuit board (41), which thermally couples all thermal connecting elements (85) belonging to this mounting surface (421) to each other.

6. The magnetic levitation device according to any one of the preceding claims, wherein a heat conducting layer (88) is arranged between the web (8) and the back side (412) of the circuit board (41), with which heat can be transferred from the circuit board (41) to the housing (10).

7. The magnetic levitation device according to claim 6, wherein the heat conducting layer (88) is designed as a film which is attached to the back side (412) of the circuit board (41).

8. The magnetic levitation device according to any one of the claims 6 to 7, wherein the heat conducting layer (88) is made of a metallic material.

9. The magnetic levitation device according to any one of the preceding claims, wherein the control housing (102) of the housing (10) is designed with an interior space having a substantially rectangular or square cross-sectional area perpendicular to the axial direction (A).

10. The magnetic levitation device according to any one of the preceding claims, wherein the stator housing (101) of the housing (10) is designed with an interior space having a substantially round cross-sectional area perpendicular to the axial direction (A).

11. The magnetic levitation device according to any one of the preceding claims, wherein a housing cover (11) is arranged at one axial end of the magnetic levitation device, which cover closes the control housing (102).

12. The magnetic levitation device according to any one of the preceding claims, wherein the stator (2) comprises a containment can (21) which forms one axial end of the stator (2), wherein the containment can (21) has the cup-shaped recess (211).

13. The magnetic levitation device according to any one of the preceding claims, wherein the separating wall (103) comprises an inner cup (13) which is substantially designed in a cylindrical manner, and which is arranged radially inwardly with respect to the windings (61) in the interior space surrounded by the windings (61).

14. The magnetic levitation device according to any one of the preceding claims, wherein the housing (10) is designed in such a way that the coil cores (25) with the concentrated windings (61) arranged thereon can be inserted into the stator housing (101) in a first installation direction in the axial direction (A), and the control unit (40) can be inserted into the control housing (102) in a second installation direction, wherein the first installation direction is directed in the opposite direction to the second installation direction.

15. The magnetic levitation device according to any one of the preceding claims, wherein 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).