Rotor

Abstract

The invention relates to a rotor (19) for a dynamoelectric rotary machine (11), comprising a support body (4) and a plurality of magnets (2, 2b), the magnets (2, 2b) being arranged on and / or at least partly inside the support body (4) and the magnets (2, 2b) being lenticular.

Description

[0001] Description

[0002] rotor

[0003] The invention relates to a rotor for a dynamoelectric rotary machine.

[0004] Permanent-magnet synchronous machines typically use NdFeB magnets. However, the production of these magnets is energy-intensive. Furthermore, focusing on one material carries the risk that it will no longer be available or that its price will rise. Using other magnets usually results in a loss of machine dynamics.

[0005] The invention is based on the object of providing a highly dynamic machine taking into account the magnet problem.

[0006] The object is achieved by claim 1, i.e. a rotor for a dynamoelectric rotary machine, comprising a support body and a plurality of magnets, wherein the magnets are arranged on and / or at least partially within the support body, wherein the magnets are lens-shaped, wherein the magnets comprise rare earth material, wherein at least 50% of the rare earth material is cerium.

[0007] The magnets are advantageously designed as biconvex lenses and / or plano-convex lenses and / or concave-convex lenses.

[0008] The magnets are preferably laterally magnetized.

[0009] This is achieved advantageously by magnetizing the magnet from one side or surface.

[0010] In a lens-shaped magnet, the poles are preferably located on the surface facing the rotor. These magnets, particularly permanent magnets, are advantageously magnetized laterally, i.e., one can imagine a bar magnet in this regard, the ends of which, i.e., the poles facing each other, are in particular almost folded together or even folded together. In principle, a magnetic north or south pole of the rotor is advantageously formed by two adjacent poles of the same name, north-north or south-south, of the permanent magnet. This has already been described in more detail in EP 2991195 A1.

[0011] One pole of the rotor is advantageously formed by the poles of the same name of two adjacent magnets.

[0012] The supporting body is preferably ironless.

[0013] For example, by avoiding soft magnetic materials in the rotor, the motor's inductances are reduced. This allows the current to be injected more quickly into the motor winding, which in turn increases the motor's dynamics.

[0014] An embodiment is advantageous according to which the support body comprises ceramic, in particular technical ceramic and / or aluminum and / or carbon fiber reinforced plastic.

[0015] Laterally magnetized lens magnets, in particular, allow for a non-magnetic substrate material, such as technical ceramics, aluminum, or carbon fiber-reinforced plastic (CFRP). This offers many advantages, including lower weight, a lower moment of inertia, and greater rigidity. This advantageously leads to increased motor dynamics and a lower tendency to vibration.

[0016] An embodiment in which the magnets contain cerium is advantageous.

[0017] Cerium (Ce) is a much more common element than the previously used rare earth element neodymium (Nd) and is abundantly available in mining areas. Cerium has a good ecological balance and is inexpensive.

[0018] Rare earths such as neodymium and especially the heavy rare earths such as dysprosium and terbium, which are sometimes also contained as alloying elements in the permanent magnets described, mostly come from Asia.

[0019] Cerium is available worldwide and therefore contributes to the diversification of supply chains. This increases security of supply.

[0020] The magnets may also comprise an alloy comprising cerium, neodymium, iron and boron.

[0021] The magnets comprise, as already mentioned above, rare earth material, wherein at least 50% of the rare earth material is cerium.

[0022] This allows the creation of a dynamic machine that is also cost-effective.

[0023] The magnets preferably have a stoichiometric composition such as R^Fe^B. R advantageously includes the elements neodymium (Nd), praseodymium (Pr), cerium (Ce), lanthanum (La), yttrium (Y) and / or other trace elements.

[0024] Cerium preferably makes up at least 50% of R. Particularly advantageous, especially with regard to environmental aspects, are magnets made from recycled material containing neodymium, iron and / or boron.

[0025] In a further advantageous embodiment, the magnets have a shape deviation on the air gap side.

[0026] This shape deviation is advantageously formed as a linear depression with a rounded and / or flat base. The shape deviation is advantageously formed as a groove and / or ridge.

[0027] The shape deviation is advantageously formed around an outer circumference of the rotor.

[0028] This offers the advantage that a bandage, particularly one arranged on the outer circumference of the rotor, holds well and there is no risk of slipping.

[0029] Bandaging during the manufacturing process is also made easier.

[0030] The bandage is advantageously a thread bandage, wherein a bandage thread is arranged in depressions of the shape deviation.

[0031] The problem is further solved by a dynamoelectric machine having such a rotor.

[0032] The problem is further solved by a method for producing a cerium-containing magnet for such a rotor, wherein the magnet is produced by means of metal injection molding, in short: MIM.

[0033] The MIM process is a metal powder injection molding process and is known from the state of the art.

[0034] Advantageously, a shape deviation or a structure is formed on at least one side of the magnet.

[0035] Advantageously, a linear depression, in particular grooves and / or ridges, is formed.

[0036] Using the MIM process, a structured surface can be easily created, especially on the side of the magnets facing the air gap, which can be used especially for bandaging with bandaged wires. A bandage enables a smaller magnetic air gap, which leads to higher torques and improved motor dynamics.

[0037] The invention is described and explained in more detail below with reference to the exemplary embodiments shown in the figures. They show:

[0038] FIG 1 a unit comprising a carrier body and a plurality of magnets,

[0039] FIG 2 a dynamoelectric rotary machine,

[0040] FIG 3 a rotor,

[0041] FIG 4 a magnet,

[0042] FIG 5 possible lens shapes,

[0043] FIG 6 shows an exemplary manufacturing process.

[0044] FIG 1 shows a unit 1 having a carrier body 4 carrying a plurality of magnets 2 and a shaft recess 3 for a rotor 19, see FIG 2.

[0045] The supporting structure is advantageously iron-free.

[0046] The magnets 2 in the figure are biconvex lens-shaped. Other lens shapes can also be used.

[0047] The lens shapes shown in FIG. 5 are particularly advantageous: A: biconvex lens, B: plano-convex lens, C: concave-convex lens. Others are also possible.

[0048] The two curvatures of the biconvex lens-shaped magnet 2 can be identical. It is also possible for the radii of the opposing curvatures to differ. The figure also shows an axial extension of the unit 1, or rather, a length L.

[0049] The magnets 2 are advantageously laterally magnetized. This is indicated by the magnetization directions 7 and 8.

[0050] FIG 2 shows a dynamoelectric rotary machine 11, comprising a stator 10 and the rotor 19 with a shaft 12.

[0051] FIG. 3 shows the rotor 19 having a thread bandage. The bandage thread 20 advantageously lies in grooves or ridges 21, which, for example, a magnet 2b has (see FIG. 4).

[0052] However, the bandage can also be applied if the magnet has no structure or shape deviation.

[0053] FIG. 6 shows an exemplary manufacturing process. A cerium-containing magnet 2, 2b for a rotor 19 is produced by means of metal injection molding.

[0054] In a process step S1, feedstock production takes place, i.e., in particular, the production of a metal powder-binder mixture. This advantageously contains cerium in powder form.

[0055] Other materials may also be included, in particular neodymium, iron and / or boron.

[0056] In a process step S2, injection molding takes place. Advantageously, a shape deviation or structure is formed on at least one side of the magnet.

[0057] In a process step S3, debinding takes place.

[0058] In a process step S4, the magnet is sintered. This process is advantageous because it requires only a small amount of energy. The invention allows the production of a dynamic, permanently excited synchronous machine. The advantageously ironless carrier body 4 and the reduced energy requirements during magnet production particularly contribute to environmental considerations. Production is particularly sustainable when recycled material is used for feedstock production.

Claims

Patent claims 1. Rotor (19) for a dynamoelectric rotary machine (11), comprising a support body (4) and a plurality of magnets (2, 2b), wherein the magnets (2, 2b) are arranged on and / or at least partially within the support body (4), wherein the magnets (2, 2b) are lens-shaped, wherein the magnets (2, 2b) comprise rare earth material, wherein at least 50% of the rare earth material is cerium.

2. Rotor (19) according to claim 1, wherein the magnets (2, 2b) are biconvex lens-shaped and / or plano-convex lens-shaped and / or concave-convex lens-shaped.

3. Rotor (19) according to one of the preceding claims, wherein the supporting body (4) is ironless.

4. Rotor (19) according to one of the preceding claims, wherein the supporting body (4) comprises ceramic, in particular technical ceramic, and / or aluminum and / or carbon fiber reinforced plastic.

5. Rotor (19) according to one of the preceding claims, wherein the magnets (2, 2b) are laterally magnetized.

6. Rotor (19) according to one of the preceding claims, wherein the magnets (2, 2b) comprise cerium.

7. Rotor (19) according to one of the preceding claims, wherein the magnets (2, 2b) comprise cerium, neodymium, iron and boron.

8. Rotor (19) according to one of the preceding claims, wherein the magnets (2, 2b) are composed stoichiometrically as R2Fe4B, where R comprises the elements Nd, Pr, Ce, La and / or Y.

9. Rotor (19) according to one of the preceding claims, wherein the magnets (2, 2b) comprise neodymium, iron and / or boron obtained from recycled material.

10. Rotor (9) according to one of the preceding claims, wherein the magnets (2, 2b) have a shape deviation on the air gap side.

11. Rotor (19) according to claim 10, wherein the shape deviation is formed as a linear depression (21) with a rounded and / or flat base.

12. Rotor (19) according to one of the preceding claims 10 or 11, wherein the shape deviation, in particular as a groove and / or groove, is formed circumferentially on an outer circumference of the rotor.

13. Rotor (19) according to one of the preceding claims, wherein the rotor has a bandage.

14. Rotor (19) according to one of the preceding claims 11 to 13, wherein the bandage is a thread bandage, wherein a bandage thread (20) of the thread bandage is arranged in depressions (21) of the shape deviation.

15. Dynamoelectric machine (11) comprising a rotor (19) according to one of claims 1 to 14.

16. A method for producing a cerium-containing magnet (2, 2b) for a rotor (19) according to one of claims 1 to 14, wherein the magnet (2, 2b) is produced by means of metal injection molding.

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