Rotor of permanent magnet rotation machine

Abstract

A rotor according to one embodiment of the present invention comprises: a core; and a plurality of permanent magnet modules mounted on the outer circumferential surface of the core, wherein the permanent magnet module includes: a base block coupled to the outer circumferential surface of the core; a permanent magnet arranged on the base block; a cover, which covers the permanent magnet and is coupled to the base block; and a pole shoe interposed between the cover and the permanent magnet, and the pole shoe and the permanent magnet can have the same length extending in the tangential direction of the core.

Description

Rotor of permanent magnet rotator

[0001] The present invention relates to a rotor of a permanent magnet rotor capable of reducing irreversible demagnetization of a permanent magnet and reducing slot harmonic voltage components.

[0002] The rotor of a permanent magnet rotator is classified into a surface permanent magnet type rotor and an interior permanent magnet type rotor depending on the attachment location and manufacturing method of the permanent magnets. A surface permanent magnet rotor has a structure in which the permanent magnets are attached to the surface of the rotor and are exposed, while an interior permanent magnet rotor has a structure in which the permanent magnets are embedded inside the rotor and are not visible from the outside.

[0003] Depending on the load characteristics, a permanent magnet rotor with an appropriate rotor type can be selected. For example, a permanent magnet rotor with a surface-type rotor offers advantages such as higher power density and higher efficiency compared to a built-in permanent magnet rotor.

[0004] In a surface-type rotor, a protective cover made of a non-magnetic material may be placed around the outer periphery of the permanent magnet to prevent the permanent magnet from being detached or damaged due to centrifugal force when the rotor rotates at high speed. The protective cover may be secured to the radial outer periphery of the rotor core by a fastener such as a screw or holder, thereby firmly connecting and protecting the permanent magnet to the rotor.

[0005] However, the protective cover simply supports and protects the permanent magnets, and does not incorporate an electromagnetic shielding structure to protect them from irreversible demagnetization caused by fault currents. Irreversible demagnetization degrades the performance of the permanent magnets and, as it cannot be recovered, poses a critical threat to the performance of the permanent magnet rotor. Furthermore, the design of permanent magnet rotors is conservative, with increased permanent magnet usage and the use of higher-grade magnets to mitigate this risk, leading to higher costs.

[0006] Meanwhile, when a surface-type rotor with a protective cover is used in a permanent magnet generator, the no-load phase voltage and line-to-line voltage may be significantly distorted by slot harmonics. These slot harmonics are determined by the number of poles (a) of the rotor and the number of slots (b) of the stator. Specifically, when the number of slots per pole (c) is defined as b / a, and c is an integer, the voltage waveform may be significantly distorted by slot harmonics of the order [(2 × c) ± 1]. If the voltage distortion increases in this way, heat generation in the permanent magnet generator increases and performance such as power factor or efficiency deteriorates.

[0007] The purpose of the present invention is to provide a rotor of a permanent magnet rotor capable of reducing irreversible demagnetization of a permanent magnet.

[0008] In addition, an object of the present invention is to provide a rotor of a permanent magnet rotor that can reduce heat generation of the rotor and minimize performance degradation such as power factor or efficiency by configuring the rotor so as to reduce slot harmonic voltage components.

[0009] According to one embodiment of the present invention, a rotor includes a core and a plurality of permanent magnet modules mounted on an outer surface of the core, wherein the permanent magnet modules include: a base block coupled to the outer surface of the core; a permanent magnet disposed on the base block; a cover covering the permanent magnet and coupled to the base block; and a pole shoe interposed between the cover and the permanent magnet, wherein the pole shoe and the permanent magnet may have the same length extending along a tangential direction of the core.

[0010] The above-mentioned pole shoe can be formed by axially stacking a plurality of split plates formed from electrical steel plates in a predetermined shape.

[0011] The above pole shoe may include an outer surface radially outward and a contact surface radially inwardly contacting the radially outer surface of the permanent magnet.

[0012] The outer surface includes a curved surface that conforms to the shape of the inner surface of the cover, and the radius of curvature of the outer surface may be smaller than or equal to the radius of curvature of the curved portion of the cover.

[0013] The above contact surface may have the same length as the permanent magnet in the axial direction of the core.

[0014] The outer surface may include at least one pair of grooves formed to correspond to the permanent magnets, and the grooves may have an asymmetrical arc-shaped cross-section.

[0015] The two grooves forming a pair are arranged symmetrically with cross-sectional shapes that are symmetrical with respect to a reference line, and the reference line can be defined as an imaginary axis passing through the center of the circumferential length of the permanent magnet and the center of the rotor.

[0016] The cross-sectional shape of the above home portion may include a first circular arc and a second circular arc extending from the first circular arc and having a curvature smaller than that of the first circular arc.

[0017] The above first circular arc may be positioned relatively closer to the reference line than the above second circular arc.

[0018] The above-mentioned home portion includes a pair of first home portions and a pair of second home portions, and the first home portion can be positioned relatively farther away from the reference line than the second home portion.

[0019] The cross-sectional shape of the first groove may include a first circular arc and a second circular arc extending from the first circular arc and having a curvature smaller than that of the first circular arc, and the cross-sectional shape of the second groove may include a third circular arc and a fourth circular arc extending from the third circular arc and having a curvature smaller than that of the third circular arc.

[0020] The first circular arc may be positioned relatively closer to the reference line than the second circular arc, and the third circular arc may be positioned relatively closer to the reference line than the fourth circular arc.

[0021] The first groove portion and the second groove portion may have different cross-sectional sizes.

[0022] The first groove portion may be formed to have a larger cross-sectional area than the second groove portion.

[0023] The third circular arc may have a curvature radius that is 20-70% greater than the curvature radius of the first circular arc, and the fourth circular arc may have a curvature radius that is 20-70% greater than the curvature radius of the second circular arc.

[0024] The above base block may be made of a magnetic material, and the above cover may be made of a non-magnetic material.

[0025] According to an embodiment of the present invention, by applying an electromagnetic protection part to reduce irreversible demagnetization of a permanent magnet, it is possible to protect the permanent magnet from fault current and obtain the effect of enabling optimal design and cost reduction.

[0026] According to an embodiment of the present invention, by forming a groove having a specific cross-sectional shape on the opposite surface of the rotor, it is possible to reduce the slot harmonic voltage component, thereby obtaining the effect of reducing heat generation of the rotor and minimizing the deterioration of performance such as power factor or efficiency.

[0027] FIG. 1 is an enlarged view of a permanent magnet module of a rotor according to a first embodiment of the present invention.

[0028] FIG. 2 is an enlarged view of a part of an example in which a rotor according to a second embodiment of the present invention is used in a permanent magnet rotor.

[0029] Figure 3 is a detailed drawing of part A of Figure 2.

[0030] FIG. 4 is a diagram showing the no-load line-to-line voltage waveform of a permanent magnet rotor using a rotor according to a second embodiment of the present invention.

[0031] Hereinafter, the present invention will be described in detail with reference to exemplary drawings. When designating components in each drawing, it should be noted that, where possible, identical components are given the same reference numerals, even if they appear in different drawings.

[0032] In this specification, terms such as first, second, etc. may be used to describe various components, but these components are not limited in order, size, position, or importance by terms such as first, second, etc., and are named only for the purpose of distinguishing one component from another.

[0033] FIG. 1 is an enlarged view of a permanent magnet module of a rotor according to a first embodiment of the present invention.

[0034] A rotor (1) according to a first embodiment of the present invention may include a core (10) and a plurality of permanent magnet modules (20). Accordingly, the rotor according to the first embodiment of the present invention can function as a rotor of a permanent magnet motor when the rotor is used as an electric motor.

[0035] The rotor (1) can be fixedly connected to the outer surface of the shaft with the shaft (3) penetrating therethrough, and can be received in, for example, a rotor receiving hole (5; see Fig. 2) of a stator (2; see Fig. 2) and rotated together with the shaft.

[0036] In this case, the shaft (3) rotates together with the rotor (1), and the rotational power of the rotor can be transmitted to the outside or applied from the outside.

[0037] The core (10) may be formed in a drum shape, for example, using structural steel. The core may include a shaft insertion hole (11) formed to extend axially so that a shaft (3) can be inserted into the center.

[0038] For example, a core (10) may be formed to have a circular cross-section, a shaft (3) may be inserted and penetrated into the inner surface of the core, and a plurality of permanent magnet modules (20) may be arranged along the circumferential direction on the outer surface of the core, thereby forming a rotor (1).

[0039] The outer surface of the core (10) may have a circular or polygonal shape. Fig. 1 shows an example in which the outer surface of the core is formed in a circular shape, but the present invention is not necessarily limited thereto.

[0040] On the outer surface of the core (10), a plurality of fastening holes (12) for fastening members (30) that are fastened to fix the permanent magnet module (20) may be formed. For example, fastening members such as screws may be fastened to the fastening holes.

[0041] A plurality of permanent magnet modules (20) can be mounted on the outer surface of the core (10). The plurality of permanent magnet modules can be arranged in the circumferential direction of the core and stacked in the axial direction.

[0042] The number of permanent magnet modules (20) is not particularly limited, and they may be arranged alternately with different polarities along the circumference of the core (10). A plurality of permanent magnet modules may be formed to have the same structure and size.

[0043] Each permanent magnet module (20) may include a base block (21) coupled to the outer surface of the core (10); a permanent magnet (22) disposed on the base block; a cover (23) covering the permanent magnet and coupled to the base block; and a pole shoe (24) interposed between the cover and the permanent magnet.

[0044] The base block (21) can be made of a magnetic material such as iron, for example. The radially inner surface of the base block can have a curved or flat surface depending on the shape of the outer surface of the core (10).

[0045] On both sides of the circumferential direction of the base block (21), an extension portion (29) extending along the tangential direction of the core (10) can be formed, and a first through hole (31) can be formed in the extension portion parallel to a direction perpendicular to the tangential direction of the core.

[0046] The permanent magnet (22) may be positioned on the radially outer surface of the base block (21). The permanent magnet may be attached to the surface of the base block by bonding using an adhesive to prevent detachment. However, the method of attaching the permanent magnet is not necessarily limited to this, and a groove may be formed on the surface of the base block and pressed into it.

[0047] The plurality of permanent magnet modules (20) may include a plurality of N-pole permanent magnet modules and a plurality of S-pole permanent magnet modules alternately arranged on the outer surface along the circumference of the core (10).

[0048] A single permanent magnet module (20) may include a plurality of permanent magnets (22) having the same polarity. The plurality of permanent magnets may be arranged side by side and in contact with each other along the circumference of the core (10) on the base block (21). Adjacent permanent magnets may be bonded to each other using an adhesive.

[0049] The cover (23) can be made of a non-magnetic material, such as stainless steel or aluminum. The cover can be formed in a roughly box shape with one side open and a space inside.

[0050] The cover (23) may include a curved portion (25); a side wall portion (26) connected to both circumferential ends of the curved portion; and a fixed portion (27) connected to the radially inner ends of the side wall portion and extending along the tangential direction of the core (10).

[0051] The curved portion (25) may be formed in a round shape to constitute the radially outer surface of the cover (23). The curved portion of the cover may substantially face the stator.

[0052] The side wall portion (26) can constitute the circumferential surfaces of both sides of the cover (23), and can be connected to a fixed portion (27) formed by bending at the open end of the side wall portion, i.e., the radially inner end.

[0053] The fixed portion (27) may extend outward from the radially inner end of the side wall portion (26) along the tangential direction of the core (10) and overlap with one of the two side extension portions (29) of the base block (21). A second through hole (32) may be formed in the fixed portion in parallel with a direction perpendicular to the tangential direction of the core.

[0054] When the fastening member (30) is fastened to the fastening hole through the first through hole (31) of the extension (29) aligned with the fastening hole (12) of the core (10) and the second through hole (32) of the fixing member (27), the base block (21) together with the cover (23) can be fixed to the core (10), and thus the permanent magnet module (20) can be fixedly mounted on the outer surface of the core.

[0055] The fastener (30) is used to fix the cover (23) and the base block (21) to the core (10), that is, to couple the permanent magnet module (20) to the core (10). As described above, a fastener such as a screw or the like may be adopted, but is not necessarily limited thereto.

[0056] The permanent magnet (22) can be attached to the inner surface of the side wall (26) of the cover by bonding with an adhesive while being accommodated in the space within the cover (23). However, the method of attaching the permanent magnet is not necessarily limited to this.

[0057] In this way, by covering the permanent magnet (22) with the cover (23) and being coupled to the base block (21), it is possible to prevent damage or detachment of the permanent magnet due to centrifugal force when the rotor (1) rotates at high speed and to protect the permanent magnet.

[0058] The rotor (1) according to the first embodiment of the present invention may be characterized by including a pole shoe (24) interposed between a cover (23) and a permanent magnet (22) to reduce irreversible demagnetization of the permanent magnet.

[0059] The pole shoe (24) is provided with a plurality of split plates formed from electrical steel plates in a predetermined shape, and can be formed by stacking the plurality of split plates in the axial direction.

[0060] The pole shoe (24) may have an outer surface (41) that is formed convexly radially outward. The outer surface may have a curved surface that conforms to the inner surface of the curved portion (25) of the cover (23). It is preferable that the radius of curvature of the convex outer surface of the pole shoe is smaller than or equal to the radius of curvature of the curved portion of the cover.

[0061] The pole shoe (24) may have a flat contact surface (42) that contacts the radially outer surface of the permanent magnet (22) radially inwardly. The contact surface may extend the same length as the permanent magnet extends along the tangential direction of the core (10). Additionally, the contact surface may have the same length as the permanent magnet in the axial direction of the core.

[0062] The shape of the pole shoe (24) is not necessarily limited to the example described above. For example, the outer surface (41) of the pole shoe may be formed as a flat surface regardless of the shape of the cover (23). Even in this case, the pole shoe can be structurally stably positioned because it is accommodated and restrained within the cover.

[0063] The pole shoe (24) can be shaped to influence the magnetic flux generated by the permanent magnet (22). Due to the relatively low magnetic reluctance of the pole shoe compared to air, the magnetic flux can be focused in such a way that a limited region with high magnetic flux density is formed radially outwardly away from the core.

[0064] Accordingly, the pole shoe (24) together with the cover (23) can physically protect the permanent magnet (22) with complete reliability.

[0065] The pole shoe (24) constituting the permanent magnet module (20) of the rotor (1) according to the first embodiment of the present invention can act as an electromagnetic protection unit for the permanent magnet (22). In particular, the pole shoe primarily absorbs a sudden current change due to a fault current, thereby electromagnetically protecting the permanent magnet from irreversible demagnetization caused by a reverse magnetic field.

[0066] It is interpreted and evaluated that the permanent magnet module (20) applied to the rotor (1) according to the first embodiment of the present invention can reduce irreversible demagnetization by about 30 to 40% compared to a conventional permanent magnet module without an electromagnetic protection part such as a pole shoe (24).

[0067] As shown in Fig. 1, when the assembly of each permanent magnet module (20) is completed, all permanent magnet modules can be stacked in the axial direction of the core (10) and arranged in the circumferential direction.

[0068] Finally, the shaft (3) is inserted and penetrated into the inner surface of the core (10), i.e., the shaft insertion hole (11), thereby completing the rotor (1) according to the first embodiment of the present invention. This rotor (1) can be arranged in a form spaced apart from the stator within the rotor so as to face the stator (2) and rotate in one direction or in the opposite direction.

[0069] As described above, according to the first embodiment of the present invention, by applying an electromagnetic protection part to reduce irreversible demagnetization of a permanent magnet, it is possible to obtain the effect of protecting the permanent magnet from fault current and enabling optimal design and cost reduction.

[0070] FIG. 2 is an enlarged view of a part of an example in which a rotor according to a second embodiment of the present invention is used in a permanent magnet rotor, and FIG. 3 is a detailed view of part A of FIG. 2.

[0071] A rotor (1) according to a second embodiment of the present invention may include a core (10) and a plurality of permanent magnet modules (20). Accordingly, the rotor according to the second embodiment of the present invention can function as a rotor of a permanent magnet generator when the rotor is used as a generator.

[0072] The second embodiment illustrated in FIGS. 2 and 3 differs only in that a groove (40) is added to the pole shoe (24) of the permanent magnet module (20), and the remaining components are identical to those of the first embodiment. Accordingly, in describing the rotor (1) of the second embodiment, the same reference numerals are given to the same components as those of the rotor according to the first embodiment described above, and a detailed description of their configuration and function is omitted.

[0073] The rotor (1) according to the second embodiment of the present invention may be characterized by further including at least one pair of grooves (40) formed on the outer surface (41) of the pole shoe (24) constituting the permanent magnet module (20).

[0074] At least one pair of grooves (40) can be arranged correspondingly to each single pole (N pole or S pole) of the permanent magnet (22) of the permanent magnet module on the opposite surface of the permanent magnet module (20) facing the stator (2) with the gap (G; see FIG. 3) and the cover (23) interposed therebetween, more specifically on the outer surface (41) of the pole shoe (24).

[0075] For example, in the case of a 28-pole rotor (1), 56 grooves (40) can be formed in the rotor. Each groove can be formed by extending along the axial direction of the rotor from the outer surface (41) of the pole shoe (24).

[0076] The two grooves (40) forming a pair can be arranged symmetrically with respect to a reference line (L). Here, the reference line can be defined as an imaginary axis passing through the center of the circumferential length of the permanent magnet module (20) and the center of the rotor (1).

[0077] In other words, the two paired grooves (40) each have the same distance from the reference line (L). In this case, each groove can be arranged adjacent to each end of the circumferential length of the permanent magnet (22).

[0078] Each groove (40) may have an asymmetrical arc-shaped cross-section. For example, the cross-sectional shape of each groove may include a first circular arc (45) and a second circular arc (46) extending from the first circular arc and having a curvature smaller than that of the first circular arc. In addition, the first circular arc may be positioned relatively close to the reference line (L), and the second circular arc may be positioned relatively far from the reference line.

[0079] Accordingly, the two grooves (40) forming a pair can be formed with cross-sectional shapes that are symmetrical with respect to the reference line (L). The inner surface of each groove has a relatively steep curve adjacent to the reference line, while it has a relatively gentle curve farther away from the reference line.

[0080] On the opposite surface of the permanent magnet module (20), more specifically, on the outer surface (41) of the pole shoe (24), a plurality of pairs of grooves (43, 44) may be arranged for each single pole of the permanent magnet (22). That is, a pair of first grooves (43) and a pair of second grooves (44) may be formed corresponding to the permanent magnets on the outer surface (41) of the pole shoe (24).

[0081] A pair of first grooves (43) may be positioned relatively further away from the reference line (L) than a pair of second grooves (44). In this case, each of the first grooves may be positioned adjacent to each of the ends on both sides of the circumferential length of the permanent magnet (22).

[0082] The first groove (43) and the second groove (44) may each have an asymmetrical arc-shaped cross-section. For example, the cross-sectional shape of the first groove may include a first circular arc (45) and a second circular arc (46) extending from the first circular arc and having a curvature smaller than that of the first circular arc. Similarly, the cross-sectional shape of the second groove may include a third circular arc (47) and a fourth circular arc (48) extending from the third circular arc and having a curvature smaller than that of the third circular arc.

[0083] Additionally, the first circular arc (45) and the third circular arc (47) may be positioned relatively close to the reference line (L), and the second circular arc (46) and the fourth circular arc (48) may be positioned relatively far from the reference line.

[0084] Accordingly, the two first grooves (43) forming a pair can be formed with cross-sectional shapes that are symmetrical with respect to the reference line (L). The two second grooves (44) can also be formed with cross-sectional shapes that are symmetrical with respect to the reference line. The inner surface of each groove has a relatively steep curve adjacent to the reference line, while it has a relatively gentle curve farther away from the reference line.

[0085] The first groove (43) and the second groove (44) may have different cross-sectional sizes. For example, the first groove, which is located relatively far from the reference line (L), may be formed to have a larger cross-sectional area than the second groove.

[0086] For this purpose, the third circular arc (47) may have a curvature radius of 20-70% greater than the curvature radius of the first circular arc (45), and the fourth circular arc (48) may have a curvature radius of 20-70% greater than the curvature radius of the second circular arc (46).

[0087] The rotor (1) configured as described above can be arranged in a manner such that it faces the stator (2) and is spaced apart from the stator by a certain distance, i.e., a gap (G), within the rotor so that it can rotate in one direction or in the opposite direction.

[0088] Here, the stator (2) includes a coil (4) wound on the stator, may be formed in a form that allows the shaft (3) to pass through, and may be fixedly supported on a housing (not shown) of a rotating machine.

[0089] The stator (2) may be formed by, for example, forming a plurality of stator core plates made of electrical steel plates into a predetermined shape, and stacking the plurality of stator core plates in the axial direction, but is not necessarily limited thereto.

[0090] The stator (2) may include a rotor receiving hole (5) formed to extend axially so that a rotor (1) can be received at the center. In addition, the stator may include a plurality of slots (6) and a plurality of teeth (7) formed alternately around the periphery of the rotor receiving hole.

[0091] A plurality of teeth (7) can be arranged at equal intervals along the circumference of the stator (2), and a slot (6) can be formed between two adjacent teeth. A coil (4) is wound around the teeth in the slots on both sides, and a coil is wound on each tooth to form a stator.

[0092] As illustrated in Fig. 2, when the number of slots (6) of the stator (2) per pole of the rotor (1) is 6 and the number of corresponding teeth (7) is 5, a pair of first grooves (43) can be arranged to correspond to the outermost teeth on both sides among the corresponding teeth. In other words, each first groove can be arranged on the rotor to correspond to the first and fifth teeth of the stator defined along the circumferential direction.

[0093] In addition, each second groove (44) may be arranged on the rotor (1) to correspond to the second tooth (7) and the fourth tooth (7) of the stator (2) defined along the circumferential direction, but is not necessarily limited thereto.

[0094] In this way, in the rotor (1) according to the second embodiment of the present invention, at least one pair of grooves (40) are arranged on the outer surface (41) of the pole shoe (24) of the permanent magnet module (20) facing the stator (2) with the gap (G) and cover (23) therebetween, so that the permeance of the gap portion changes and the zigzag reactance is reduced, thereby reducing the slot harmonic voltage component.

[0095] Specifically, the occurrence of a fringing effect in the rotor (1) is increased by at least one pair of grooves (40), thereby increasing the effective air gap length within the rotor. In addition, the length of the rotor surface is reduced by the grooves.

[0096] Moreover, since the cross-section of the groove (40) has an asymmetrical arc shape, the effective gap length can be further increased and the length of the rotor surface can be further reduced compared to the case of a groove having a symmetrical cross-section.

[0097] Due to their influence, the permeance of the gap portion decreases, which in turn reduces the zigzag reactance and reduces harmonic components. In other words, at least one pair of grooves (40) can act as a voltage filter capable of removing specific harmonics from the permanent magnet rotator.

[0098] FIG. 4 is a diagram showing the no-load line-to-line voltage waveform of a permanent magnet rotor using a rotor according to a second embodiment of the present invention.

[0099] In FIG. 4, the solid line indicates the no-load line-to-line voltage waveform of a permanent magnet rotor using a rotor according to the second embodiment of the present invention illustrated in FIG. 2, and the dotted line indicates the no-load line-to-line voltage waveform of a permanent magnet rotor according to the prior art without a groove.

[0100] Here, the conventional permanent magnet rotor includes a stator having, for example, six slots per pole, in which case the 11th and 13th harmonics are mainly generated.

[0101] As can be seen in Fig. 4, by using the rotor according to the second embodiment of the present invention, it can be confirmed that the distortion of the no-load line voltage is visibly and significantly reduced in the permanent magnet rotor.

[0102] When analyzing the waveform by fast Fourier transform (FFT), it is shown that the total harmonic distortion (THD) of the no-load line voltage in the second embodiment of the present invention is significantly reduced from 8.03% in the prior art to 1.38%.

[0103] Additionally, in the second embodiment of the present invention, the 11th harmonic is reduced from 6.07% of the prior art to 0.82%, and the 13th harmonic is reduced from 5.13% of the prior art to 0.59%.

[0104] Moreover, when the fundamental wave (first component) of the counter electromotive force of the no-load line voltage in the prior art is 100%, the fundamental wave in the second embodiment of the present invention shows 100.2%, so it can be seen that the fundamental wave is maintained at an equivalent level.

[0105] Accordingly, the rotor (1) according to the second embodiment of the present invention has the advantage that, when a rotor employing the rotor (1) is used as a generator, the slot harmonic voltage component can be reduced by forming at least one pair of grooves (40) on the outer surface (41) of the pole shoe (24) constituting the permanent magnet module (20), and the fundamental voltage can be maintained at the same level.

[0106] As described above, according to the second embodiment of the present invention, by forming a groove having a specific cross-sectional shape on the opposite surface of the rotor, it is possible to reduce the slot harmonic voltage component, thereby obtaining the effect of reducing heat generation of the rotor and minimizing the deterioration of performance such as power factor or efficiency.

[0107] The above description is merely an example of the technical idea of ​​the present invention, and those skilled in the art will appreciate that various modifications and variations can be made without departing from the essential characteristics of the present invention.

[0108] Accordingly, the embodiments disclosed in this specification and drawings are intended to illustrate, rather than limit, the technical concepts of the present invention, and the scope of the technical concepts of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the following claims, and all technical concepts within the scope equivalent thereto should be construed as being included within the scope of the present invention.

[0109] The present invention is useful for providing a high-performance permanent magnet rotator that can prevent performance degradation.

Claims

1. Core and, A plurality of permanent magnet modules mounted on the outer surface of the above core Including, The above permanent magnet module, A base block coupled to the outer surface of the above core; A permanent magnet placed on the base block; A cover covering the permanent magnet and coupled to the base block; and A pole shoe interposed between the above cover and the above permanent magnet Including, The above pole shoe and the above permanent magnet are rotors whose lengths extending along the tangential direction of the core are the same.

2. In paragraph 1, The above pole shoe is a rotor formed by axially stacking a plurality of split plates formed of electrical steel plates in a predetermined shape.

3. In paragraph 1, The above Paul Shoe, The outer surface radially outward, A contact surface that contacts the radially outer surface of the permanent magnet radially inward A rotor including:

4. In paragraph 3, The above outer surface includes a curved surface that conforms to the shape of the inner surface of the cover, A rotor having a radius of curvature of the outer surface of the above-mentioned cover that is less than or equal to the radius of curvature of the curved portion of the above-mentioned cover.

5. In paragraph 3, The above contact surface is a rotor having the same length as the permanent magnet in the axial direction of the core.

6. In paragraph 3, The outer surface includes at least one pair of grooves formed corresponding to the permanent magnet, The above home portion is a rotor having an asymmetrical arc-shaped cross-section.

7. In paragraph 6, The two above-mentioned grooves forming a pair are arranged symmetrically with cross-sectional shapes symmetrical with respect to the reference line, The above reference line is a rotor defined as an imaginary axis passing through the center of the circumferential length of the permanent magnet and the center of the rotor.

8. In paragraph 7, A rotor having a cross-sectional shape of the above-mentioned home portion, including a first circular arc and a second circular arc extending from the first circular arc and having a curvature smaller than that of the first circular arc.

9. In paragraph 8, The first circular arc is a rotor positioned relatively closer to the reference line than the second circular arc.

10. In paragraph 7, The above home portion includes a pair of first home portions and a pair of second home portions, A permanent magnet rotor in which the first groove is located relatively farther away from the reference line than the second groove.

11. In paragraph 10, The cross-sectional shape of the first groove includes a first circular arc and a second circular arc extending from the first circular arc and having a curvature smaller than that of the first circular arc. A rotor having a cross-sectional shape of the second groove, including a third circular arc and a fourth circular arc extending from the third circular arc and having a curvature smaller than that of the third circular arc.

12. In paragraph 11, The above first arc is positioned relatively closer to the reference line than the above second arc, The third circular arc is a rotor positioned relatively closer to the reference line than the fourth circular arc.

13. In paragraph 11, A rotor in which the first groove and the second groove have different cross-sectional sizes.

14. In paragraph 13, A rotor in which the first groove portion is formed with a larger cross-sectional area than the second groove portion.

15. In paragraph 13, A rotor in which the third circular arc has a curvature radius that is 20-70% greater than the curvature radius of the first circular arc, and the fourth circular arc has a curvature radius that is 20-70% greater than the curvature radius of the second circular arc.

16. In any one of paragraphs 1 to 15, The above base block is made of magnetic material, The above cover is a rotor made of non-magnetic material.

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