Synchronous motor comprising at least one stator and rotor comprising rotor permanent magnets, method for producing rotor permanent magnets for rotor of synchronous motor

Abstract

The invention relates to a synchronous motor comprising at least one stator and a rotor comprising rotor permanent magnets, characterized in that the rotor comprises a shaft element in addition to the rotor permanent magnets, the rotor permanent magnets comprising a first permanent magnet element and a second permanent magnet element, wherein the first permanent magnet element mainly comprises or consists of a first hard magnetic material, and wherein the second permanent magnet element mainly comprises or consists of a second hard magnetic material.

Description

Technical Field

[0001] The present invention relates to a synchronous motor comprising at least one stator and a rotor, the rotor comprising rotor permanent magnets.

[0002] Furthermore, the present invention relates to a pump comprising a synchronous motor according to the present invention.

[0003] Furthermore, the present invention relates to a method for manufacturing rotor permanent magnets of a rotor of a synchronous motor according to the present invention. Background Art

[0004] Synchronous motors are well known and are now particularly used as drives, for example for pumps, especially synchronous pumps. Such motors generally comprise a rotating rotor having a metal shaft and comprising rotor permanent magnets which are typically mounted on the shaft; such a rotor generally transmits torque to drive an actuator (such as a pump unit). Such a rotor having a metal shaft and comprising rotor permanent magnets is generally arranged such that the rotor permanent magnets arranged around the metal shaft interact with corresponding stator means in the assembled electric motor, wherein such rotor permanent magnets arranged around the metal shaft comprise at least one permanent magnet element.

[0005] Thus, such rotor permanent magnets are generally at least partially or in certain regions thereof, for example, embedded therein, comprising one or more permanent magnet elements, wherein such one or more permanent magnet elements are generally made of a hard magnetic material (i.e., having a relatively high remanence or remanent magnetization). Although certain hard magnetic materials, such as rare earth hard magnetic materials, generally have a higher magnetic coercivity compared to, for example, ferrites and are more sensitive, especially to corrosion if exposed to water and / or moisture, other hard magnetic materials, such as ferrites, are less sensitive to water contact (or are stable in water); however, such less sensitive hard magnetic materials generally have a lower remanence. Thus, with regard to electric motors for, for example, water pumps, it is generally and conventionally known to use a rotor having a rotor permanent magnet with at least one permanent magnet element in such a manner that, -- the permanent magnet element(s) is / are (allowed to be) exposed to water or moisture and thus need to be made of or comprise a hard magnetic material such as ferrite which is less sensitive to water contact (or is stable in water). --or in such a way that at least one permanent magnet element of the rotor permanent magnet comprises a high coercivity - hard magnetic material (such as a rare earth hard magnetic material), wherein such a permanent magnet element is encapsulated in a watertight manner, i.e., for example, by using a water - tight housing as part of the rotor permanent magnet to shield water contact, the water - tight housing being, for example, a water - tight housing made of metal (and, for example, welded to the shaft element), or by overmolding at least one permanent magnet element (the permanent magnet element of the rotor permanent magnet comprising a high remanence - hard magnetic material sensitive to water) with a protective encapsulation formed, for example, by high - pressure injection molding. Both of the above - known solutions have drawbacks, typically including, --if a hard magnetic material less sensitive to water contact (such as ferrite) is used, the electromagnetic performance is lower (such as an increase in phase current), and --the expense (and additional cost) of implementing a water - tight housing in the case of using a high remanence - hard magnetic material that needs to be shielded from water and / or moisture. Summary of the Invention

[0006] The object of the present invention is to provide a technically simple, effective and cost - effective solution for providing a rotor for a synchronous motor, wherein the rotor, in addition to a shaft element, further comprises a rotor permanent magnet, which is configured such that it has a relatively elevated electromagnetic performance and, in particular, does not necessarily require a water - tight housing made of a high remanence - hard magnetic material that needs to shield water and / or moisture. Another object of the present invention is to provide a corresponding pump comprising a synchronous motor according to the present invention, especially for a hydraulic system and especially for pumping water, and to provide a corresponding method for manufacturing the rotor permanent magnet of the rotor for a synchronous motor.

[0007] The object of the present invention is achieved by a synchronous motor comprising at least one stator and a rotor, the rotor comprising a rotor permanent magnet, characterized in that, in addition to the rotor permanent magnet, the rotor further comprises a shaft element, wherein the rotor permanent magnet comprises a first permanent magnet element and a second permanent magnet element or consists of a first permanent magnet element and a second permanent magnet element, wherein the first permanent magnet element mainly comprises a first hard magnetic material or consists of a first hard magnetic material, and wherein the second permanent magnet element mainly comprises a second hard magnetic material or consists of a second hard magnetic material.

[0008] Thus, according to the present invention, advantageously, a relatively high degree of flexibility can be achieved in the design of the rotor permanent magnet, and in particular, the rotor permanent magnet can be provided in such a way that both the first permanent magnet element and the second permanent magnet element contribute to the magnetic performance of the synchronous motor. Furthermore, it is advantageously possible (by using such a rotor design with such rotor permanent magnets) to realize an electric motor having advantageous electrical or electromagnetic properties and / or performance. That is, for example (but not necessarily), such rotor permanent magnets can be used in a single-phase (or more than single-phase) synchronous motor, which includes, for example, at least one stator winding, such as a U-shaped laminated stator core having, for example, two poles. The rotor is arranged between the magnetic poles and includes rotor permanent magnets.

[0009] In particular, according to the present invention, the first and second permanent magnet elements can be realized in two different steps. For example, the first permanent magnet element is realized as an inner core, and the second permanent magnet element is realized as an outer core.

[0010] In particular, according to the present invention, it is advantageous that both the first hard magnetic material and the second hard magnetic material are moldable materials.

[0011] Advantageously, thereby, the rotor permanent magnet (or the rotor except for the shaft element) can be realized by injection molding of the first hard magnetic material and the second hard magnetic material, in particular by overmolding the second hard magnetic material onto the first hard magnetic material, that is, overmolding the second permanent magnet element onto the first permanent magnet element. Thus, according to the present invention, it is advantageously possible to combine the injection (molding) steps of two (or even more) plastic magnetic materials (or multiple plastic magnetic materials), and in particular, use the last step to protect the other or multiple plastic magnetic materials from external contact, such as contact with fluids.

[0012] According to the present invention, it is also advantageously possible and preferred that the first and second hard magnetic materials are axially adjacent (adjacent to each other) along a part of the shaft element and are positioned parallel to the rotor rotation axis, wherein in particular the radial extensions of both the first and second hard magnetic materials are substantially the same.

[0013] Advantageously, thereby, the rotor permanent magnet (or the rotor except for the shaft element) can be easily and cost-effectively realized, in particular by using two injection molding steps.

[0014] According to the present invention, it is further advantageously possible and preferred that the first hard magnetic material is exclusively positioned in the radially inner region of the rotor permanent magnet with respect to the rotor rotation axis, and wherein the second hard magnetic material is mainly positioned in the radially outer region of the rotor permanent magnet with respect to the rotor rotation axis.

[0015] Therefore, according to the present invention, it is advantageously possible that the second hard magnetic material (i.e., the second permanent magnet element) can at least radially protect the first hard magnetic material (i.e., the first permanent magnet element).

[0016] In particular, according to the present invention, it is advantageously possible and preferred that the second hard magnetic material is radially adjacent to the first hard magnetic material along the radial outer surface of the first hard magnetic material.

[0017] Thereby, advantageously, the rotor or the rotor permanent magnet of the present invention can be realized and implemented in a relatively simple and effective manner.

[0018] According to the present invention, it is further advantageously possible and preferred that the first permanent magnet element is formed to be substantially cylindrical in the region of the shaft element corresponding to the first maximum radius and / or around the shaft element, in particular around the outer cylindrical or substantially cylindrical surface of the shaft element, and wherein the second permanent magnet element is formed to be cylindrical in the region around the first permanent magnet element corresponding to the second maximum radius, in particular around the outer substantially cylindrical or substantially cylindrical surface of the first permanent magnet element.

[0019] Thus, according to the present invention, the first and second hard magnetic materials (i.e., the first and second permanent magnet elements) can be advantageously realized as concentric, more or less cylindrical elements.

[0020] In particular, according to the present invention, it is advantageously possible and preferred that both the first permanent magnet element and the second permanent magnet element extend along a certain length parallel to the rotation axis of the rotor, and this length is in particular less than the length of the shaft element.

[0021] Thereby, advantageously, the rotor or the rotor permanent magnet of the present invention can be realized and implemented in a relatively simple and effective manner; in particular, advantageously, it is possible to provide the possibility that the shaft element is (axially) longer than the first and second permanent magnet elements, and thus can transmit (or apply) torque to a downstream actuator, such as a pump unit.

[0022] According to the present invention, it is further advantageously possible and preferred that the shape of the first permanent magnet element is substantially cylindrical, in particular around the outer cylindrical or substantially cylindrical surface of the shaft element, in the region of the shaft element corresponding to the first maximum radius and / or around the shaft element, wherein, axially, the first permanent magnet element extends along a certain length parallel to the rotation axis of the rotor, and wherein the second permanent magnet element extends parallel to the rotation axis of the rotor along the total extension length of the second permanent magnet element, wherein -- along the extension length of the first permanent magnet element parallel to the rotation axis of the rotor, the second permanent magnet element is formed to be cylindrical in the region around the first permanent magnet element corresponding to the second maximum radius, in particular around the outer cylindrical or substantially cylindrical surface of the first permanent magnet element, and -- extending parallel to the rotor rotation axis beyond the first permanent magnet element, especially at both ends of the first permanent magnet element, the second permanent magnet element being shaped as a cylinder, especially around the outer cylindrical or substantially cylindrical surface of the shaft element, also in the region around the shaft element corresponding to the second maximum radius.

[0023] Advantageously, the rotor or rotor permanent magnet of the present invention can be realized and implemented in a relatively simple and effective manner, and in particular, the second permanent magnet element is provided such that it completely surrounds the first permanent magnet element (and extends axially along a specific part of the shaft element); thus, the first permanent magnet element is at least approximately and assuming that the cylindrical outer surface of the shaft element corresponds to a cylindrical shell (with an outer shell diameter twice the first maximum radius), and the second permanent magnet element is at least approximately and assuming that the cylindrical outer surface of the first permanent magnet element corresponds to a cylindrical shell (with an outer shell diameter twice the second maximum radius).

[0024] Furthermore, according to the present invention, it is advantageously possible and preferred that, in addition to the shaft element, the second permanent magnet element completely surrounds the first permanent magnet element, wherein in particular, in addition to the shaft element, the second hard magnetic material completely surrounds the first hard magnetic material, wherein in particular the first hard magnetic material is thereby protected or sealed from the influence of external fluids, especially from external water or moisture in the external air, i.e., outside the rotor and / or the rotor permanent magnet.

[0025] Advantageously, the rotor or rotor permanent magnet of the present invention can be realized and implemented in a relatively simple and effective manner; in particular, it is advantageously possible to use a material that is sensitive to water and / or moisture (but has, for example, superior magnetic properties (compared to the second permanent magnet element and / or the second hard magnetic material)) as the first permanent magnet element and / or as the first hard magnetic material, and to protect (or seal or encapsulate) the first permanent magnet element and / or the first hard magnetic material by means of the second permanent magnet element and / or as the second hard magnetic material. In particular, it is advantageously possible, especially by providing the corresponding shapes of the first and / or second permanent magnet elements and / or hard magnetic materials, to enhance the magnetic properties of the first permanent magnet element and / or the first hard magnetic material by means of the second permanent magnet element and / or the second hard magnetic material. In particular, according to the present invention, it is advantageously possible to shape the first and / or second permanent magnet element and / or the hard magnetic material such that, in a radial cross-section, i.e., a cross-section perpendicular to the rotational axis of the rotor, the first and / or second permanent magnet element and / or the hard magnetic material is shaped differently from a mere cylinder (i.e., cylindrical, meaning having a respective (radial) outer surface that is equidistant radially from the rotational axis of the rotor), in particular, by varying the distance of the (radial) outer surface of the first and / or second permanent magnet element and / or the hard magnetic material from the rotational axis of the rotor, for example, in a fluctuating manner or varying around or along the circumference of the rotor permanent magnet. In particular, this results in the following advantages: Rare earth magnetic materials, which are commonly used for their magnetism, are generally sensitive to corrosion when in contact with water. By means of a second hard magnetic material (e.g., a hard ferrite material) that completely surrounds the first hard magnetic material (e.g., a rare earth magnetic material), the rare earth magnetic material is protected by an injection-molded ferrite layer, and advantageously, it is possible that both materials, i.e., the entire rotor volume, contribute to the magnetic characteristics of the rotor. The internally injection-molded layer, i.e., the first permanent magnet element, typically comprises rare earth metals, such as NdFeB or SmFeN (injection-molded in an isotropic or anisotropic manner), while the outer layer, i.e., the second permanent magnet element, typically comprises or consists of injection-molded ferrite, which is particularly stable in water.

[0026] Furthermore, according to the present invention, it is advantageously possible and preferred that the first hard magnetic material is a moldable material comprising or consisting of a first hard magnetic component and a molding component, and wherein the second hard magnetic material is a moldable material comprising or consisting of a second hard magnetic component and another molding component.

[0027] Thereby, advantageously, the rotor or the rotor permanent magnet of the present invention can be realized and implemented in a relatively simple and effective manner; in particular, it is advantageously possible to provide the first hard magnetic material in the form of a mixture that comprises or consists of a first hard magnetic component and a molding component. In particular, the first hard magnetic component itself is the part of the first hard magnetic material that provides its magnetism, while the molding component of the first hard magnetic material corresponds to a material, in particular a thermoplastic material, by means of which the mixture (of the first hard magnetic material) can be used as a moldable material. Similarly, the second hard magnetic component itself is preferably the part of the second hard magnetic material that provides its magnetism, while the other molding component of the second hard magnetic material corresponds to such a material, in particular a thermoplastic material, by means of which the mixture (of the second hard magnetic material) can be used as a moldable material. In the context of the present invention, according to one embodiment of the present invention, the molding component (of the first hard magnetic material) and the other molding component (of the second hard magnetic material) are different materials, which are selected such that the resulting rotor permanent magnet (and its connection to the shaft element of the rotor) has appropriate mechanical properties, in particular sufficient mechanical strength, elasticity and / or load capacity, especially considering the temperature range used and / or considering its sensitivity to vibration. However, according to another embodiment of the present invention, the molding component (of the first hard magnetic material) and the other molding component (of the second hard magnetic material) are the same material, i.e., there is only one molding component for both the first and second hard magnetic materials, and this (unique) molding component is again selected such that the resulting rotor permanent magnet including the first and second permanent magnet elements (and its connection to the shaft element of the rotor) has appropriate mechanical properties, in particular sufficient mechanical strength, elasticity and / or load capacity, especially considering the temperature range used and / or considering its sensitivity to vibration.

[0028] Furthermore, according to the present invention, it is advantageously possible and preferred that the first hard magnetic component is or comprises at least one of the following: --SmFeN, --NdFeB --or other hard magnetic materials that are prone to corrosion, and / or wherein the second hard magnetic component is or comprises at least one of the following: --ferrite, --SmCo, --AlNiCo, --MnAlC, --one or more iron nitrides of iron nitride, in particular one or more of: Fe2N, Fe3N4, Fe4N, Fe7N3 and Fe16N2, or any hard magnetic material that is stable in a humid environment (and thus, corrosion should be prevented).

[0029] Advantageously, the rotor or rotor permanent magnet of the present invention can be realized and implemented in a relatively simple and effective manner, and in particular, the first and second hard magnetic materials can be appropriately selected to enhance the magnetic properties of the rotor permanent magnet and / or the electric motor.

[0030] Furthermore, according to the present invention, it is advantageously possible and preferred that the first hard magnetic material and / or the first permanent magnet element has or comprises a specific first magnetization pattern, and / or wherein the second hard magnetic material and / or the second permanent magnet element has or comprises a specific second magnetization pattern.

[0031] Advantageously, the rotor or rotor permanent magnets of the present invention can be implemented and implemented in a relatively simple and effective manner, and in particular, the first and / or second magnetization modes can be appropriately selected to enhance the magnetic characteristics of the rotor permanent magnets and / or the electric motor.

[0032] Furthermore, the present invention relates to a pump comprising a synchronous motor according to the present invention, in particular a single-phase or three-phase synchronous motor.

[0033] Furthermore, the present invention relates to a method for manufacturing a rotor permanent magnet for a rotor of a synchronous motor according to the present invention, wherein the rotor permanent magnet comprises or consists of a first permanent magnet element and a second permanent magnet element located on a shaft element, wherein the first permanent magnet element mainly comprises or consists of a first hard magnetic material, and wherein the second permanent magnet element mainly comprises or consists of a second hard magnetic material, wherein in particular both the first hard magnetic material and the second hard magnetic material are moldable materials, wherein the method comprises the following steps: -- In a first step, molding the first hard magnetic material, in particular substantially axially around the shaft element -- In a second step, molding the second hard magnetic material, in particular substantially axially around the shaft element and / or around the first hard magnetic material, wherein in particular a first magnetic cage is used during the first step and / or a second magnetic cage is used during the second step, wherein the first magnetic cage and / or the second magnetic cage achieve -- A specific first magnetization mode of the first hard magnetic material and / or the first permanent magnet element, and / or -- A specific second magnetization mode of the second hard magnetic material and / or the second permanent magnet element.

[0034] These and other features, characteristics and advantages of the present invention will become apparent from the following detailed description in conjunction with the accompanying drawings, which illustrate the principles of the present invention by way of example. This description is given by way of example only and does not limit the scope of the present invention. The reference figures cited below refer to the accompanying drawings. Description of the Drawings

[0035] Figure 1 The electric motor of the present invention, which is a synchronous motor and is part of an assembly with a pump or pump element, is schematically and exemplarily shown in a perspective view.

[0036] Figure 2 The top view (or more precisely, a cross-sectional view with a cross-sectional plane perpendicular to the axis of rotation) of the electric motor of the present invention, which is an example of a single-phase synchronous electric motor with a stator and a rotor, is schematically and exemplarily shown, wherein the stator is implemented as a U-shaped laminated stator core with two poles.

[0037] Figure 3 , 4 and 6 schematically and exemplarily show different examples of the rotor and rotor permanent magnets of the present invention by means of cross-sectional views along the rotational axis of the rotor, the rotor and rotor permanent magnets having a first permanent magnet element and a second permanent magnet element.

[0038] Figure 5 Schematically and exemplarily shows a method for manufacturing a rotor permanent magnet for a rotor of a synchronous motor according to the present invention.

[0039] Figure 7 Schematically and exemplarily shows, in a cross-sectional view, the electric motor of the present invention as a synchronous motor which is part of an assembly having a pump or pump element.

[0040] Figure 8 Also schematically and exemplarily shows, in a cross-sectional view and a projection parallel to the rotational axis of the rotor, an embodiment of the rotor and rotor permanent magnets of the present invention, the rotor and rotor permanent magnets having a first permanent magnet element and a second permanent magnet element. Detailed Description

[0041] The present invention will be described with reference to specific embodiments and with reference to certain drawings, but the present invention is not limited thereto, but is only limited by the claims. The described drawings are only schematic and not restrictive. In the drawings, for purposes of illustration, the dimensions of some elements may be exaggerated and not drawn to scale.

[0042] When referring to a singular noun, the indefinite or definite article is used, such as "a", "an", "the", which includes the plural of the noun, unless otherwise expressly stated.

[0043] Furthermore, the terms first, second, third, etc. used in the specification and claims are used to distinguish similar elements and are not necessarily used to describe an order or temporal sequence. It should be understood that the terms so used are interchangeable where appropriate, and that the embodiments of the present invention described herein are capable of operating in other sequences than those described or illustrated herein.

[0044] In Figure 1 , a perspective view of the electric motor 100 of the present invention, which is exemplarily shown as a (single-phase) synchronous motor, is schematically shown. The synchronous motor 100 is shown as being part of an assembly having a pump or pump element: In Figure 1 the upper part, the electric motor 100 is schematically shown, while in Figure 1At the lower part of, the pump 200 (or pump unit 200) is schematically shown. In particular, the electric motor 100 has a rotational axis, and the pump 200, which is a rotary pump and thus also has a rotational axis, is aligned along the rotational axis 120' of the electric motor 100 (at Figure 1 the lower part of).

[0045] Figure 2 A top view (or more precisely, a cross-sectional view with a cross-sectional plane perpendicular to the rotational axis 120') of an example of an electric motor according to the invention for a single-phase synchronous motor having a stator and a rotor is schematically and exemplarily shown, wherein the stator is implemented as a U-shaped laminated stator core having two poles. As is well known, for a synchronous motor, the electric motor 100 includes a stator and a rotor 120. In particular, the stator is exemplarily shown as having a U-shaped laminated stator core, which has two poles 111, 112 and which exemplarily has or is arranged with at least one stator winding. The rotor 120 having or defining the rotational axis 120' is arranged between the poles 111, 112 of the stator core, and the rotor 120 includes rotor permanent magnets ( Figure 2 not specifically shown in). The U-shaped laminated stator core 110 is exemplarily shown as having one or more stator windings 110' arranged in a part thereof remote from the poles 111, 112.

[0046] In a conventionally known manner, the poles 111, 112 may include (or the laminated stator core 110 may include) recesses 115 in order to increase the starting torque of the electric motor 100; however, this is only exemplarily shown in Figure 2 . The recesses 115 create small asymmetries in the sheet metal part of the laminated stator core 110, thereby producing an angular change of the cogging torque with respect to the electrical torque, thus improving (or enabling) the starting of the motor. If present, such recesses 115 may be arranged in different ways, for example radially opposite to each other (with respect to the rotational axis 120') and their connecting line (not shown) is offset by an angle with respect to the connecting line (not shown) between the poles 111, 112 via the rotational axis 120' (indicated by "0°" in Figure 2 ).

[0047] Figure 3 , 4 and 6 schematically and exemplarily show different examples of the rotor 120 according to the invention. The rotor 120 includes a (rotor) shaft element 125 and a rotor permanent magnet 126 having a first permanent magnet element 121 and a second permanent magnet element 122. In all embodiments according to the invention, the first permanent magnet element 121 mainly comprises or consists of a first hard magnetic material, while the second permanent magnet element 122 mainly comprises or consists of a second hard magnetic material.

[0048] In a manner similar to Figure 1 the way, Figure 7 the electric motor 100 (as a synchronous motor) of the present invention, which is part of an assembly having a pump 200 or a pump element 200, is also shown schematically and by way of example by means of a sectional view along the axis of rotation 120' of the rotor 120. Figure 7 The rotor 120 (assembled) of the present invention, which is part of the electric motor 100, is specifically shown, wherein the rotor 120 includes a (rotor) shaft element 125 and rotor permanent magnets 126 (having a first permanent magnet element 121 and a second permanent magnet element 122; however, these permanent magnet elements 121, 122 are not specifically shown and represented by reference numerals in Figure 7 it.

[0049] In particular, the first hard magnetic material is a moldable material including or consisting of a first hard magnetic component and a molding component, and the second hard magnetic material is a moldable material including or consisting of a second hard magnetic component and another molding component. In particular, the first hard magnetic material is or corresponds to a mixture containing or consisting of a first hard magnetic component and a molding component. In particular, the first hard magnetic component itself is the part of the first hard magnetic material that provides its magnetic properties, while the molding component of the first hard magnetic material corresponds to a material, in particular a thermoplastic material, by means of which the mixture (of the first hard magnetic material) can be used as a moldable material. Similarly, the second hard magnetic component itself is preferably the part of the second hard magnetic material that provides its magnetic properties, while the other molding component of the second hard magnetic material corresponds to such a material, in particular a thermoplastic material, by means of which the mixture (of the second hard magnetic material) can be used as a moldable material. In the context of the present invention, the molding component (of the first hard magnetic material) and the other molding component (of the second hard magnetic material) can be different materials (which are especially selected such that the resulting rotor permanent magnet 126 (and its connection to the shaft element 125 of the rotor 120) has appropriate mechanical properties, in particular sufficient mechanical strength. However, the molding component (of the first hard magnetic material) and the other molding component (of the second hard magnetic material) can also be the same material, i.e., there is only one molding component for the first and second hard magnetic materials, and this (unique) molding component is again selected such that the resulting rotor permanent magnet 126 including the first and second permanent magnet elements 121, 122 (and its connection to the shaft element 125 of the rotor 120) has appropriate mechanical properties.

[0050] In particular, according to the present invention, the first hard magnetic component is or includes at least one of the following: --SmFeN, --NdFeB, -- or other hard magnetic materials that are prone to corrosion (i.e., resistant to corrosion and / or contact with water or (atmospheric) moisture).

[0051] Furthermore, according to the present invention, the second hard magnetic component is or comprises at least one of the following: -- ferrite, -- SmCo, AlNiCo, MnAlC, -- one or more iron nitrides, especially one or more of: Fe2N, Fe3N4, Fe4N, Fe7N3, and Fe16N2, -- or any hard magnetic material that is stable in a humid environment (therefore, corrosion should be prevented).

[0052] Figure 3 An embodiment according to the present invention is shown by means of a cross-sectional view along the rotational axis 120' of the rotor 120, wherein the shaft element 125 extends along the rotational axis 120' of the rotor 120 and thus has a certain length (of the shaft element 125). In Figure 3 the embodiment shown, the rotor permanent magnet 126 (i.e., its first permanent magnet element 121 and second permanent magnet element 122) extends along a length L1 parallel to the rotational axis 120' of the rotor, and this length L1 is less than the length of the shaft element 125, i.e., the extension length L1 of both the first and second permanent magnet elements 121, 122 only extends along a part (length L1) of the (total) length of the shaft element 125. Furthermore, Figure 3 it is shown that the rotor permanent magnet 126 is arranged concentrically around the shaft element 125: the shape of the first permanent magnet element 121 is substantially cylindrical (or more precisely, a cylindrical shell), especially around the outer cylindrical or substantially cylindrical surface of the shaft element 125. In particular, the first permanent magnet element 121 extends in the region of the shaft element 125 corresponding to the first maximum radius r1 and / or radially around the shaft element 125. Similarly, the second permanent magnet element 122 is shaped cylindrically, especially around the outer substantially cylindrical or substantially cylindrical surface of the first permanent magnet element 121, and (radially) in the region around the first permanent magnet element 121 corresponding to the second maximum radius r2.

[0053] Figure 4Another embodiment according to the invention is shown by means of a sectional view along the axis of rotation 120' of the rotor 120, in which the rotor permanent magnets 126 are again arranged substantially concentrically around the shaft element 125: The shape of the first permanent magnet element 121 is substantially cylindrical (or more precisely a cylindrical shell), in particular around the outer cylindrical or substantially cylindrical surface of the shaft element 125: Radially, the first permanent magnet element 121 extends in the region of the shaft element 125 corresponding to the first maximum radius r1 and / or around the shaft element 125, and axially, it extends along a length L1 parallel to the axis of rotation 120' of the rotor. The second permanent magnet element 122 extends axially parallel to the axis of rotation 120' of the rotor along the total extension length L2 of the second permanent magnet element 122 (the extension length of the second permanent magnet element 122 exceeds the corresponding extension length L1 of the first permanent magnet element 121); along the extension length L1 of the first permanent magnet element 121, the second permanent magnet element 122 is shaped as a cylinder (or more precisely, shaped as a cylindrical shell), in particular around the outer cylindrical or substantially cylindrical surface of the first permanent magnet element 121, and the second permanent magnet element 122 extends radially in the region around the first permanent magnet element 121 corresponding to the second maximum radius r2. Outside the first permanent magnet element 121 (parallel to the axis of rotation 120' of the rotor), in particular at both ends of the first permanent magnet element 121, the second permanent magnet element 122 is also shaped as a cylinder (or more precisely a cylindrical shell), but around the outer cylindrical or substantially cylindrical surface of the shaft element 125, and also extends radially in the region around the shaft element 125 corresponding to the second maximum radius r2. Thereby, the second permanent magnet element 122 completely surrounds (or encloses) the first permanent magnet element 121 and can thus shield or protect the first permanent magnet element 121 from, for example, external fluids, especially water and / or moisture, and thereby advantageously avoid corrosion of the components of the first permanent magnet element 121, especially the first hard magnetic material or its components.

[0054] It should be understood that with respect to Figure 3 the embodiment shown and Figure 4 the embodiment shown, the surface of the shaft element 125 (at least along a part or the entire length of the extension length L1 of the first permanent magnet element 121) (i.e., the interface between the shaft element 125 and the first permanent magnet element 121) can be cylindrical or at least substantially cylindrical, but need not be: The outer surface of the shaft element 125 can also include recesses and protrusions (e.g., in the manner of a gear) of any shape, for example in order to provide an increased attachment of the rotor permanent magnets 126 to the shaft element 125. Similarly, it should also be understood that with respect to Figure 3 the embodiment shown and Figure 4In the illustrated embodiment, the (radially outer) surface of the first permanent magnet element 121 (at least along a part of the extension length L1 of the first permanent magnet element 121 or along the entire length of the extension length L1 of the first permanent magnet element 121) (i.e., the interface between the first permanent magnet element 121 and the second permanent magnet element 122) can be cylindrical or at least substantially cylindrical, but it is not necessary that: the outer surface of the first permanent magnet element 121 can also include recesses and protrusions (of any shape) (e.g., in the manner of a gear), for example in order to provide an increased attachment of the second permanent magnet element 122 to the first permanent magnet element 121 and / or in order to impart to the rotor permanent magnet 126 specific and advantageous magnetic properties and / or a specific orientation of the magnetic field generated by the positions and / or shapes of the first and second permanent magnet elements 121, 122 and / or their interaction. In Figure 8 an example of such a configuration is schematically and exemplarily shown (i.e., where the (radially outer) surface of the first permanent magnet element 121, i.e., the interface between the first and second permanent magnet elements 121, 122 is not cylindrical (or substantially cylindrical)) (in a cross-sectional view and in a projection parallel to the rotor rotation axis 120'): From Figure 8 and the outer shape or profile of the (radial) outer surface of the first permanent magnet element 121, it can be seen that the outer shape or profile includes protrusions extending radially outwards (at three specific angles around the rotor rotation axis 120', i.e., around the rotor rotation axis 120', these three angles of the maximum radial extension of the first permanent magnet element 121 are approximately spaced 120° apart). However, different numbers of such protrusions (around the rotor rotation axis 120') are equally possible, for example only two protrusions, or four protrusions, or five protrusions, or six protrusions, or more than six protrusions. In addition, the shape of the protrusions (outer shape or profile) can be different from Figure 8 the shape shown, for example having a triangular, square, pentagonal or hexagonal profile.

[0055] Figure 6 Another embodiment according to the invention is also shown by means of a cross-sectional view along the rotation axis 120' of the rotor 120, in which the first and second hard magnetic materials (or the first and second permanent magnet elements 121, 122) are axially adjacent to each other along a part of the shaft element 125 and parallel to the rotor rotation axis 120'. In particular, according to Figure 6 the representation, the radial extensions of the first and second hard magnetic materials (or the first and second permanent magnet elements 121, 122) are substantially the same, and the first and second permanent magnet elements 121, 122 are positioned adjacent to each other along the shaft element 125 of the rotor 120.

[0056] Figure 5A method for manufacturing a rotor permanent magnet 126 for a synchronous motor according to the present invention is schematically and exemplarily shown: According to the present invention, the method includes a step of molding a first hard magnetic material, in particular substantially axially around a shaft element 125. In addition, it includes a step of molding a second hard magnetic material, in particular substantially axially around the shaft element 125 and / or around the first hard magnetic material. These steps are schematically shown in Figure 6 the upper and lower parts: The upper part shows the shaft element 125 positioned within a first tool including a first magnetic cage 121'. By means of the first tool, the extension of the first permanent magnet element 121 is defined, and the first permanent magnet element 121 is realized by injection molding the first hard magnetic material. The lower part shows the shaft element 125 (together with the already molded first hard magnetic material or first permanent magnet element 121, i.e., in place) positioned within a second tool including a second magnetic cage 122'. By means of the second tool, the extension of the second permanent magnet element 122 is defined, and the second permanent magnet element 122 is realized by injection molding the second hard magnetic material. In particular according to the present invention, the first magnetic cage 121' is used during the first step and / or the second magnetic cage 122' is used during the second step in order to achieve a respective specific first and / or specific second magnetization pattern of the first and / or second hard magnetic materials and / or of the first and / or second permanent magnet elements 121, 122 (or within the first and / or second hard magnetic materials) and / or of the first and / or second permanent magnet elements 121, 122 (or within the first and / or second permanent magnet elements 122). Advantageously, a specific first magnetization pattern can thus be achieved within the first hard magnetic material and / or the first permanent magnet element 121 and / or a specific second magnetization pattern within the second hard magnetic material and / or the second permanent magnet element 122 in such a way that a specific and advantageous magnetic property is imparted to the rotor permanent magnet 126 and / or a specific orientation of the magnetic field generated by the position and / or shape of the first and second permanent magnet elements 121, 122 and / or by their interaction.

Claims

1. A synchronous motor (100) comprising at least one stator and a rotor (120), wherein the rotor (120) comprises rotor permanent magnets (126), It is characterized in that In addition to the rotor permanent magnet (126), the rotor (120) further comprises a shaft element (125), wherein the rotor permanent magnet (126) comprises a first permanent magnet element (121) and a second permanent magnet element (122), or consists of the first permanent magnet element (121) and the second permanent magnet element (122), wherein the first permanent magnet element (121) mainly comprises a first hard magnetic material, or consists of a first hard magnetic material, and wherein the second permanent magnet element (122) mainly comprises a second hard magnetic material, or consists of a second hard magnetic material.

2. The synchronous motor (100) according to claim 1, characterized in that: The first hard magnetic material and the second hard magnetic material are both moldable materials.

3. The synchronous motor (100) according to any one of the preceding claims, characterized in that The first and second hard magnetic materials are positioned axially adjacent to each other along a portion of the shaft element (125) and parallel to the rotor rotation axis (120'), In particular, the radial extension of both the first and the second hard magnetic material is essentially the same.

4. The synchronous motor (100) according to any one of the preceding claims, characterized in that The first hard magnetic material is located exclusively in a radially inner region of the rotor permanent magnet (126) relative to the rotor rotation axis (120'), and wherein the second hard magnetic material is located predominantly in a radially outer region of the rotor permanent magnet (126) relative to the rotor rotation axis (120'), In particular, along the radial outer surface of the first hard magnetic material, the second hard magnetic material is radially adjacent to the first hard magnetic material.

5. The synchronous motor (100) according to any one of the preceding claims, characterized in that The first permanent magnet element (121) is shaped as a substantially cylindrical shape in a region of the shaft element (125) corresponding to a first maximum radius (r1) and / or around the shaft element (125), in particular around an outer cylindrical or substantially cylindrical surface of the shaft element (125), and wherein the second permanent magnet element (122) is shaped as a cylindrical shape in a region around the first permanent magnet element (121) corresponding to a second maximum radius (r2), in particular around an outer substantially cylindrical or substantially cylindrical surface of the first permanent magnet element (121), In particular, the first permanent magnet element (121) and the second permanent magnet element (122) both extend along a certain length (L1) parallel to the rotor rotation axis (120'), wherein the length (L1) is in particular smaller than the length of the shaft element (125).

6. The synchronous motor (100) according to any one of the preceding claims, characterized in that The first permanent magnet element (121) is shaped substantially cylindrically in a region of the shaft element (125) corresponding to a first maximum radius (r1) and / or around the shaft element (125), in particular around an outer cylindrical or substantially cylindrical surface of the shaft element (125), wherein the first permanent magnet element (121) extends along a certain length (L1) parallel to the rotor rotation axis (120'), and wherein the second permanent magnet element (122) extends parallel to the rotor rotation axis (120') along a total extension length (L2) of the second permanent magnet element (122), wherein - along an extension length (L1) of the first permanent magnet element (121) parallel to the rotor rotation axis (120'), the second permanent magnet element (122) is cylindrically shaped in a region around the first permanent magnet element (121) corresponding to a second maximum radius (r2), in particular around an outer cylindrical or substantially cylindrical surface of the first permanent magnet element (121), and - extending beyond the first permanent magnet element (121) parallel to the rotor rotation axis (120'), in particular at both ends of the first permanent magnet element (121), the second permanent magnet element (122) is shaped as a cylinder, in particular around the outer cylindrical or substantially cylindrical surface of the shaft element (125), also in the area around the shaft element (125) corresponding to the second maximum radius (r2).

7. The synchronous motor (100) according to any one of the preceding claims, characterized in that The second permanent magnet element (122) completely surrounds the first permanent magnet element (121) except for the shaft element (125), wherein, in particular, apart from the shaft element (125), the second hard magnetic material completely surrounds the first hard magnetic material, In particular, the first hard magnetic material is thereby protected or sealed from external fluids, in particular from external water or moisture in the external air.

8. The synchronous motor (100) according to any one of the preceding claims, characterized in that The first hard magnetic material is a moldable material including or consisting of a first hard magnetic component and a molding component, and wherein the second hard magnetic material is a moldable material including or consisting of a second hard magnetic component and another molding component.

9. The synchronous motor (100) according to any one of the preceding claims, characterized in that The first hard magnetic component is or includes at least one of the following: --SmFeN, --NdFeB, -- or other hard magnetic materials that are susceptible to corrosion, And / or wherein the second hard magnetic component is or includes at least one of the following: --Ferrite, --SmCo, AlNiCo, MnAlC, - one or more iron nitrides, in particular one or more of: Fe2N, Fe3N4, Fe4N, Fe7N3 and Fe16N2, -- or any hard magnetic material that is stable in a humid environment.

10. The synchronous motor (100) according to any one of the preceding claims, characterized in that The first hard magnetic material and / or the first permanent magnet element (121) has or includes a specific first magnetization mode, and / or wherein: The second hard magnetic material and / or the second permanent magnet element (122) has or includes a specific second magnetization mode.

11. A pump (200) comprising a synchronous motor (100) according to any one of the preceding claims, in particular a single-phase or three-phase synchronous motor (100).

12. Method for producing a rotor permanent magnet (126) of a rotor (120) of a synchronous motor (100) according to any one of the preceding claims, The rotor permanent magnet (126) comprises a first permanent magnet element (121) and a second permanent magnet element (122) located on the shaft element (125), or consists of the same, wherein the first permanent magnet element (121) mainly comprises a first hard magnetic material, or consists of the same, and The second permanent magnet element (122) mainly comprises a second hard magnetic material, or is composed thereof, wherein both the first hard magnetic material and the second hard magnetic material are moldable materials, The method comprises the following steps: - In a first step, molding the first hard magnetic material, in particular substantially axially around the shaft element (125) - in a second step, molding the second hard magnetic material, in particular substantially axially around the shaft element (125) and / or around the first hard magnetic material, In particular, a first magnetic cage (121') is used during the first step and / or a second magnetic cage (122') is used during the second step, wherein the first magnetic cage and / or the second magnetic cage (121', 122') are implemented a specific first magnetization mode of the first hard magnetic material and / or the first permanent magnet element (121), and / or - a specific second magnetization mode of the second hard magnetic material and / or the second permanent magnet element (122).

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