Rotor yoke of rotor of rotating electric machine

Abstract

The invention relates to a rotor yoke (1) of a rotor of a rotary electric machine, comprising a yoke base (3) and at least one slot plate (4) fixed to the yoke base. The slot plate (4) comprises a plurality of through slots (10) formed by radially distributed slot portions (11), and wherein a slot-free plate portion (13) is formed between two adjacent slot portions (11).

Description

Technical Field

[0001] The present invention relates to rotating electric machines, and more particularly to rotating electric machines with improved energy efficiency. Background Art

[0002] In the case of electric motors, an electric machine is a device used to convert electrical energy into mechanical energy, and vice versa in the case of generators. They are generally composed of a rotor (rotating part), a static element called a stator, bearings that connect the static and rotating parts, and a housing that not only forms the housing for the above-mentioned systems but also facilitates integration with other auxiliary systems.

[0003] The energy efficiency of a motor is related to its energy consumption and performance. The performance of a machine can be negatively affected by various factors, such as mechanical losses caused by excessive wear and electrical losses.

[0004] Electrical losses generally include Joule effect losses, hysteresis losses, and eddy current losses.

[0005] Due to the variations in magnetic flux, eddy current losses are generated in the various components of the motor. In the case of synchronous motors, the fundamental component of the magnetic flux seen by the rotor is static and does not generate eddy current losses. However, effects such as the opening of stator slots and the supply of power by the frequency converter can cause harmonics in the rotor flux waveform, resulting in eddy current losses in all the solid and conductive parts that make up the rotor, such as the steel yoke and permanent magnets.

[0006] Since eddy current losses depend on the square of the solid cross-section over which the magnetic flux varies, solutions to reduce eddy current losses often involve dividing the body into smaller cross-sections.

[0007] For example, document CN116054519 shows an axial magnetic field motor rotor structure, whose solution includes an iron core, which includes a plurality of surface layer bodies and a plurality of interpole bodies, and the surface layer bodies and the interpole bodies are connected in an interval sequence to form an iron core. A plurality of permanent magnets are arranged circumferentially at certain intervals, and the surface layer bodies at least partially cover the upper surface of the permanent magnets, and the interpole bodies are installed between two adjacent permanent magnets. The core may include a groove formed in the surface layer body and the interpole body, which is designed to reduce the formation of eddy current losses. The groove is shown in the document as an annular groove, which extends through the surface body and through the side plate of the interpole body, but does not completely pass through the interpole side plate, so that the core plate is not broken.

[0008] Document CN110391703 shows a rotor yoke for an axial flux permanent magnet motor. The rotor yoke comprises a solid annular plate-shaped rotor yoke body with inner and outer annular protrusions and an annular recess between the inner and outer protrusions for mounting a permanent magnet. The annular recess comprises multiple radially distributed annular grooves to reduce eddy current losses.

[0009] Although the above cited documents show solutions for reducing eddy current losses in rotors, there is still a need in the art for more effective solutions in reducing eddy current losses and improving the energy efficiency of rotating electrical machines. Summary of the Invention

[0010] Purpose of the present invention

[0011] One of the objects of the present invention is to provide a rotor yoke for a rotating electrical machine capable of reducing the occurrence of eddy current losses, increasing the energy efficiency of the machine, while exhibiting improved manufacturing and mechanical robustness.

[0012] Another object of the present invention is to provide a rotor yoke for a rotary electric machine that is capable of reducing the occurrence of eddy current losses while maintaining the rigidity of the yoke without adversely affecting the robustness of the electric machine.

[0013] Another object of the present invention is to provide a rotor yoke for a rotating electric machine that reduces the occurrence of eddy current losses by enabling magnets to be correctly and safely positioned in the rotor of the electric machine.

[0014] Brief Description of the Invention

[0015] The present invention achieves the above object by a rotor yoke of a rotor of a rotating electrical machine, the rotor yoke comprising:

[0016] A yoke base and at least one slot plate welded to the yoke base.

[0017] The flat base is arranged to receive at least one slot plate, and the slot plate comprises a plurality of through slots formed by radially distributed slot portions, wherein a slotless plate portion is formed between two adjacent slot portions, so that the slot plate comprises a plurality of slotless plate portions.

[0018] In one embodiment of the present invention, the rotor yoke includes a plurality of magnets fixed on the slot plate, wherein a central radial geometric line of each magnet coincides with a central radial geometric line matching each slotless portion.

[0019] Furthermore, in one embodiment of the present invention, each of the plurality of grooveless plate portions has a recess for dispensing glue to the magnets.

[0020] The yoke base may comprise an annular disc having a central hole, an outer rim wall, an inner rim wall, and in this embodiment, the flat base is a lowered flat base formed between the outer rim wall and the inner rim wall.

[0021] In one embodiment of the present invention, the outer edge wall comprises a cutout wall formed by a plurality of wall sections of a first height and a plurality of wall sections of a second height, wherein the second height is higher than the first height. In this embodiment, the sections of the plurality of wall sections of the first height have an arc length greater than an arc length of the sections of the plurality of wall sections of the second height.

[0022] In one embodiment of the present invention, each of the plurality of slotless plate portions is radially aligned with a portion of the plurality of wall portions at the second height.

[0023] Preferably, each slot portion comprises a continuous zigzag through slot having substantially parallel portions, the lengths of the portions decreasing as they approach the central hole.The continuous zigzag through slot may advantageously be formed by laser cutting.

[0024] In an embodiment of the invention, the rotor yoke comprises two identical slot plates welded to a yoke base. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will now be described in more detail with reference to the accompanying drawings, in which:

[0026] Figure 1 is a perspective view of a rotor yoke according to one embodiment of the present invention, with magnets fixed to the yoke;

[0027] Figure 2 is a perspective view of a rotor yoke according to an embodiment of the present invention;

[0028] Figure 3 is a perspective top view of a base of a rotor yoke according to one embodiment of the present invention;

[0029] Figure 4 is a bottom perspective view of a base of a rotor yoke according to one embodiment of the present invention;

[0030] Figure 5 is an exploded view of a portion of an outer edge wall of a base of a rotor yoke according to one embodiment of the present invention;

[0031] Figure 6 is a top view of a base and a slot plate of a rotor yoke according to one embodiment of the present invention;

[0032] Figure 7 is a top view of a slot plate of a rotor yoke according to an embodiment of the present invention;

[0033] Figure 8 is a front view of two slot plates of a rotor yoke according to an embodiment of the present invention;

[0034] Figure 9 is a schematic diagram of five magnets fixed to a rotor yoke according to one embodiment of the present invention, with the yoke also shown; and

[0035] Figure 10 FIG. 1 is a top view of five magnets fixed to a rotor yoke according to an embodiment of the present invention, with the yoke also shown. DETAILED DESCRIPTION

[0036] Now it will be based on Figures 1 to 10 The present invention has been described with reference to the preferred embodiments shown.

[0037] The present invention includes a rotor yoke for a rotating electrical machine, such as a motor or a generator. The structure and function of rotors of this type are known to those skilled in the art, and therefore, only the elements and features necessary for a person skilled in the art to fully understand the rotor yoke of the present invention will be described in detail in this specification.

[0038] Figure 1 A rotor yoke 1 according to the invention is shown, more particularly a rotor yoke for an axial flux machine, which is arranged to receive a plurality of magnets 2 .

[0039] Figure 2 The rotor yoke 1 is shown without the plurality of magnets 2 .

[0040] The rotor yoke 1 includes a yoke base 3 and at least one slot plate 4 fixed to the yoke base 3. In the embodiment of the present invention shown, the slot plate 4 is fixed to the yoke base 3 by welding, but in other embodiments the fixing method may be different, such as using screws, rivets or glue.

[0041] It must be emphasized that the term "trough plate" as used herein may include both a one-piece plate and a plurality of separate plate segments fixed to the yoke base 3 to form a plate.

[0042] like Figure 3 and Figure 4 As shown, in the embodiment shown in the drawings, the yoke base 3 has an annular disk with a central hole 5 , an outer peripheral wall 6 , an inner peripheral wall 7 and an inner wing 8 surrounding the central hole 5 .

[0043] Between the outer rim wall 6 and the inner rim wall 7, the disc has a flat annular base 9 arranged to receive at least one slot plate 4. In the embodiment shown in the drawings, the flat annular base 9 is a lowered annular base, but other shapes may equally well be used in alternative embodiments.

[0044] The outer edge wall 6, which serves as a structural support ring, preferably comprises a cutout wall, such as Figure 5 is better shown in the exploded view.

[0045] In this embodiment, the cutout wall thus comprises a plurality of wall portions of a first height 6a and a plurality of wall portions of a second height 6b, the second height being higher than the first height, thereby forming teeth 6b. It is worth noting that in an alternative arrangement of the invention, these two portions may be of the same height, without defining teeth 6b.

[0046] Figure 6 The slot plate 4 is shown, which is received on the lowered flat annular wall of the yoke base, Figure 7 The isolated state of the board is shown.

[0047] The groove plate 4 is annular, and a plurality of through grooves 10 are formed on its surface.

[0048] The through grooves 10 are preferably formed by laser cutting and are distributed radially along the plate 4 .

[0049] In the embodiment shown in the drawings, the plurality of through slots 10 are formed by radially distributed slot portions 11. One of each slot portion 11 preferably comprises a continuous zigzag through slot 12, such that the slot 12 has substantially parallel portions whose lengths decrease as they approach the central hole 5.

[0050] In an embodiment of the present invention, wherein the trough plate is formed of a plurality of plate segments fixed to the base, the trough portions are correspondingly formed in the plate segments.

[0051] In an alternative embodiment of the present invention, the continuous zigzag through-channel may be formed by a plurality of substantially parallel portions extending radially.

[0052] Additionally, the slots 12 may alternatively be formed by substantially parallel portions of other shapes, such as straight portions or arcuate segments.

[0053] Since the slots 12 are formed by laser cutting in the preferred embodiment, the starting point of the continuous slot may comprise a small hole created by the cutting process.

[0054] Fabrication using laser cutting seeks to utilize thinner beams / slots than thinner sheets to produce the slots 12. The smaller thickness of the slots means that the magnetic permeability of the yoke is not adversely affected.

[0055] A grooveless plate portion 13 is formed between two adjacent groove portions 11, so that the groove plate 4 has a plurality of grooveless plate portions 13. Therefore, each of the grooveless portions 13 extends in a radius portion between the inner and outer edges of the annular plate.

[0056] like Figure 6 As shown, in the embodiment shown, each of the non-grooved portions 13 is radially aligned with one of the plurality of wall portions of the second height 6b of the outer edge cutout wall 6 of the base plate 3. However, in other embodiments, such alignment may not exist.

[0057] The non-grooved portion 13 helps maintain the rigidity of the assembly and achieves a one-piece structure and structural robustness.

[0058] In embodiments of the invention, in which the slotted plate is formed by a plurality of plate segments fixed to a base, the slot-free portions may be respectively formed on the edges of the plate segments, or alternatively, the slot-free portions may be formed by gaps between the segments.

[0059] In one embodiment of the invention, the rotor yoke comprises two identical, overlapping slot plates fixed to the yoke base 3. The fixing can be performed, for example, by welding, glue or screws. Figure 8 Two identical, overlapping channel plates 4, 15 are shown, which may be welded to the yoke base 3. However, in alternative embodiments the base may be formed from a single plate or even from a plurality of plates.

[0060] Figure 9 and Figure 10 The fixing of the magnets 2 to the slot plate 4 of the rotor yoke 1 is schematically shown. These figures show the fixing of five magnets, thereby allowing a portion of the plate 4 to be visualized, but it should be understood that more magnets can be fixed. It is worth noting that the magnets mentioned in the present invention can be composed of multiple magnet segments or a single-piece magnet.

[0061] like Figure 9 As shown, in a preferred embodiment of the present invention, the center of each magnet of the rotor is aligned with one of the slotless portions 13.

[0062] This alignment can be defined by coinciding the L-center radial line of the magnet with the center line of the slotless portion 13 (see Figure 10 ), which is advantageous because the yoke region in the center of the magnet is a region of lower magnetic induction.

[0063] In the embodiment of the invention shown in the drawings, the groove portion 11 includes a recess 14 that can be used to distribute glue for fastening the magnets. However, it should be emphasized that in alternative embodiments of the invention, the recess may not be present and the glue may be placed directly on the plate 4.

[0064] Thus, the rotor yoke of the present invention provides a structure that reduces the occurrence of eddy current losses while maintaining the rigidity of the yoke, and enables the magnets to be correctly and securely fixed to the rotor of the machine. Furthermore, the alignment between the center of the magnet and the slot-free portion of the slot plate, as well as the intermittent presence of the yoke and support ring, significantly contributes to reducing eddy current losses.

[0065] Having described the preferred exemplary embodiment of the present invention, it should be understood that the scope of the present invention encompasses other possible variations of the described inventive concept, being limited only by the content of the appended claims and the potential equivalents therein.

Claims

1. A rotor yoke (1) of a rotor of a rotating electrical machine, characterized in that include: yoke base (3); as well as at least one slot plate (4), fixed to the yoke base (3), wherein the flat base (9) is arranged to receive the at least one slot plate (4); A slot plate (4) comprising a plurality of through slots (10) formed by radially distributed slot portions (11); A non-grooved plate portion (13) is formed between two adjacent groove portions (11), so that the groove plate (4) includes a plurality of non-grooved plate portions (13).

2. The rotor yoke (1) according to claim 1, characterized in that The invention comprises a plurality of magnets fixed on the slot plate (4), wherein the central radial geometric line (L) of each magnet coincides with the central radial geometric line matched with each slotless part (13).

3. The rotor yoke (1) according to claim 1 or 2, characterized in that Each of the plurality of slot portions (11) has a recess (14) for dispensing glue to the magnet.

4. The rotor yoke (1) according to any one of claims 1 to 3, characterized in that The yoke base (3) comprises an annular disk with a central hole (5), an outer edge wall (6) and an inner edge wall (7), wherein the flat base (9) is a lowered flat base formed between the outer edge wall (6) and the inner edge wall (7).

5. The rotor yoke (1) according to claim 4, characterized in that The outer edge wall (6) includes a cutout wall formed by a plurality of wall portions (6a) of a first height and a plurality of wall portions (6b) of a second height, wherein the second height is higher than the first height.

6. The rotor yoke (1) according to claim 5, characterized in that Each of the plurality of grooveless plate portions (13) is radially aligned with a portion of the plurality of wall portions at the second height (6b).

7. The rotor yoke (1) according to any one of claims 1 to 6, characterized in that Each of the slot portions (11) includes a continuous zigzag through-slot (12) having substantially parallel portions whose length decreases as it approaches the central hole (5).

8. The rotor yoke (1) according to claim 7, characterized in that The continuous Z-shaped through groove (12) is formed by laser cutting.

9. The rotor yoke (1) according to any one of claims 1 to 6, characterized in that Each of the slot portions (11) comprises a continuous zigzag through-slot having a plurality of substantially parallel radially extending portions.

10. The rotor yoke (1) according to any one of claims 1 to 9, characterized in that It comprises two slot plates (4, 15).

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