Coreless rotor structure and permanent magnet motor

Abstract

The invention belongs to the field of motor technical equipment, and particularly relates to a coreless rotor structure and a permanent magnet motor. The coreless rotor structure comprises a rotor shaft and an excitation magnetic conduction assembly, the excitation magnetic conduction assembly comprises an excitation layer and a magnetic conduction layer arranged on the excitation layer, the stator structure, the excitation layer and the magnetic conduction layer are sequentially arranged in the axial direction of the rotor shaft, the excitation layer comprises a plurality of first permanent magnets which are magnetized in the axial direction of the rotor shaft, and the magnetic conduction layer comprises a plurality of second permanent magnets which are magnetized in the axial direction of the rotor shaft. The magnetizing directions of the at least two first permanent magnets are opposite, the magnetic conductive layer comprises a plurality of second permanent magnets which are magnetized along the circumferential tangential direction, the first permanent magnets are circumferentially arranged along the circumferential direction of the rotor shaft, the second permanent magnets are used for magnetically conducting two adjacent first permanent magnets which are opposite in magnetizing direction, and the number of the excitation magnetic conductive assemblies is two. The stator structure is located between the two excitation layers, and a magnetic loop is formed between the two excitation magnetic conduction assemblies.

Description

Technical Field

[0001] The present invention belongs to the field of motor technology equipment, and in particular relates to an iron-coreless rotor structure and a permanent magnet motor. Background Art

[0002] The iron core is the magnetic conductive material of a motor and is commonly found in both the rotor and stator. The iron core provides a low-reluctance magnetic path for the stator and rotor magnetomotive force (MMF), helping to reduce magnetic flux leakage within the motor and converging the stator and rotor magnetic fields within the air gap. Consequently, the presence of the iron core contributes to the motor's high torque density.

[0003] However, the physical properties of the iron core material cause a series of problems in motor applications, including:

[0004] 1) The alternating magnetic field in the core generates core losses, which increase with increasing magnetic field and alternating frequency. 2) The core experiences magnetic saturation, meaning that when the core magnetic density reaches a certain value, the core magnetic resistance increases significantly, thereby removing the magnetomotive force originally in the air gap and causing the relationship between torque and current to no longer be linear.

[0005] 3) The difference in magnetic resistance between the core and the air gap causes the air gap magnetic resistance to change unevenly, resulting in the existence of uncontrollable cogging torque in the permanent magnet motor;

[0006] 4) The radial electromagnetic force transmitted through the stator teeth will cause vibration and noise problems in the motor.

[0007] The ironless motor is a special motor structure, which is characterized by the absence of iron core material inside the motor. The benefits of eliminating the iron core material to the motor are:

[0008] 1) No core loss;

[0009] 2) There is no magnetic saturation phenomenon of the iron core, and the current and torque are linearly related;

[0010] 3) No cogging torque and corresponding low electromagnetic torque ripple;

[0011] 4) Low electromagnetic vibration noise.

[0012] Although ironless motors have many advantages, they also have a significant disadvantage: they can severely reduce the torque density of the motor. Therefore, improving the torque density of ironless motors is a major challenge in the research of this type of motor. Summary of the Invention

[0013] The purpose of the embodiments of the present application is to provide an iron-coreless rotor structure, aiming to solve the problem of how to improve torque density and avoid magnetic leakage.

[0014] To achieve the above objectives, the technical solution adopted in this application is:

[0015] In a first aspect, a coreless rotor structure is provided, which cooperates with a stator structure. The coreless rotor structure includes: a rotor shaft and an excitation magnetic conductive component, the rotor shaft passes through the stator structure, the excitation magnetic conductive component includes an excitation layer that is arranged on the outer sleeve of the rotor shaft and opposite to the stator structure, and a magnetic conductive layer that is arranged on the outer sleeve of the rotor shaft, the magnetic conductive layer is located on the surface of the excitation layer facing away from the stator structure, the excitation layer includes a plurality of first permanent magnets that are magnetized axially along the rotor shaft, and the magnetization directions of at least two of the first permanent magnets are opposite, the magnetic conductive layer includes a plurality of second permanent magnets that are magnetized tangentially along the circumference, and the magnetization directions of at least two of the second permanent magnets are opposite, each of the first permanent magnets and each of the second permanent magnets are arranged along the circumference of the rotor shaft, two excitation magnetic conductive components are arranged, the stator structure is located between the two excitation layers, and a magnetic circuit is formed between the two excitation magnetic conductive components.

[0016] In some embodiments, the magnetization directions of any two adjacent first permanent magnets are opposite.

[0017] In some embodiments, the magnetization directions of any two adjacent second permanent magnets are opposite.

[0018] In some embodiments, the two excitation layers are arranged in an axial array along the rotor shaft.

[0019] In some embodiments, the two magnetic conductive layers are arranged in a mirror image relative to the stator structure.

[0020] In some embodiments, the magnetic conductive layer further includes a third permanent magnet, the third permanent magnet is located between the two second permanent magnets, and the magnetization direction of the third permanent magnet is along the axial direction of the rotor shaft.

[0021] In some embodiments, the magnetization directions of any two adjacent third permanent magnets are opposite.

[0022] In some embodiments, the excitation magnetic conductive component further includes an end cover, and the end cover is disposed on the magnetic conductive layer.

[0023] In some embodiments, the end cover is provided with a plurality of positioning grooves arranged along the circumference of the rotor shaft, and each of the second permanent magnets is respectively disposed in each of the positioning grooves.

[0024] In a second aspect, a permanent magnet motor is provided, which includes the coreless rotor structure. The permanent magnet motor also includes the stator structure, and the stator structure includes a fixing member and a coil winding arranged on the stator fixing member.

[0025] The beneficial effect of the present application is that the coreless rotor structure plays the role of the rotor yoke iron core through the two magnetic conductive layers. The two magnetic conductive layers not only have the effect of collecting magnetic flux and avoiding magnetic leakage, but also the two magnetic conductive layers simultaneously enhance the magnetic flux entering the air gap through their own magnetic field, playing an excitation role, so that the coreless rotor structure not only has the characteristics of low torque pulsation, low vibration noise, torque linearity, no core loss, no magnetic saturation problem, etc., but also can improve torque density and avoid magnetic leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or exemplary technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0027] Figure 1 This is a schematic diagram of the principle of the coreless rotor structure provided by an embodiment of the present application;

[0028] Figure 2 This is a schematic diagram of the principle of a coreless rotor structure provided by another embodiment of the present application;

[0029] Figure 3 This is a schematic diagram of the principle of a coreless rotor structure provided by another embodiment of the present application;

[0030] Figure 4 yes Figure 1 A schematic diagram of stacking the first permanent magnet and the second permanent magnet;

[0031] Figure 5 This is an equivalent schematic diagram of the permanent magnet circuit inside the permanent magnet motor of the present application;

[0032] Figure 6 This is a schematic diagram of the equivalent magnetic circuit of the yoke of a permanent magnet motor including an iron core in the prior art;

[0033] Figure 7 This is a schematic diagram of the equivalent magnetic circuit of a permanent magnet motor in the prior art, in which the yoke does not contain an iron core;

[0034] Figure 8 Schematic diagram of an explosion of a permanent magnet motor provided in another embodiment of the present application.

[0035] Among them, the reference numerals in the figures are:

[0036] 100, coreless rotor structure; 200, excitation magnetic permeable assembly; 205, rotor shaft; 210, excitation layer; 201, first permanent magnet; 220, magnetic permeable layer; 202, second permanent magnet; 203, third permanent magnet; 204, end cap; 206, partition; 110, air gap; 300, stator structure; 301, fixing member; 302, coil winding; 207, positioning slot; DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0038] It should be noted that when a component is referred to as being "fixed on" or "disposed on" another component, it may be directly on the other component or indirectly on the other component. When a component is referred to as being "connected to" another component, it may be directly or indirectly connected to the other component. The terms "upper", "lower", "left", "right", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of description and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on this application. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances. The terms "first" and "second" are only used for the purpose of convenience of description and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0039] See also Figures 1 to 8 An embodiment of the present application provides an ironless rotor structure 100 and a permanent magnet motor having the same, wherein the ironless rotor structure 100 can be coaxial with and opposite to the stator structure 300 and jointly form an air gap 110, a stator through hole is opened at the center position of the stator structure 300, and the rotor shaft 205 can be connected to the stator structure 300 through a bearing arranged in the through hole.

[0040] See also Figure 8The coreless rotor structure 100 includes a rotor shaft 205 and an excitation magnetic conductive assembly 200. The rotor shaft 205 passes through the stator through-hole. The excitation magnetic conductive assembly 200 includes an excitation layer 210 that surrounds the rotor shaft 205 and is arranged opposite the stator structure 300, and a magnetic conductive layer 220 that surrounds the rotor shaft 205. It is understood that the excitation layer 210 and the magnetic conductive layer 220 are both annular in shape, and the stator structure 300, the excitation layer 210, and the magnetic conductive layer 220 are all coaxially arranged. The air gap 110 is formed between the excitation layer 210 and the stator structure 300. The magnetic conductive layer 220 is located on the surface of the excitation layer 210 that faces away from the stator structure 300 or the air gap 110.

[0041] See also Figure 1 The excitation layer 210 includes a plurality of first permanent magnets 201 that are magnetized axially along the rotor shaft 205, and the magnetization directions of at least two of the first permanent magnets 201 are opposite. The magnetic conductive layer 220 includes a plurality of second permanent magnets 202 that are magnetized tangentially along the circumference, and the magnetization directions of at least two of the second permanent magnets 202 are opposite. Each of the first permanent magnets 201 and each of the second permanent magnets 202 are arranged circumferentially in sequence along the circumference of the rotor shaft 205. The second permanent magnets 202 are used to conduct magnetic field between two adjacent first permanent magnets 201 with opposite magnetization directions. Two excitation magnetic conductive components 200 are arranged, and the stator structure 300 is located between the two excitation layers 210, and a magnetic circuit is formed between the two excitation magnetic conductive components 200. It can be understood that two first permanent magnets 201 with opposite magnetization directions on the same excitation layer 210 conduct magnetic conduction through the corresponding second permanent magnets 202, that is, the magnetic flux is input from one of the first permanent magnets 201 to the second permanent magnet 202, and then from the second permanent magnet 202 to the other first permanent magnet 201.

[0042] See also Figure 1 It can also be understood that, for ease of description, the two excitation layers 210 are respectively referred to as the first excitation layer 210 and the second excitation layer 210. The magnetic conductive layer 220 corresponding to the first excitation layer 210 is the first magnetic conductive layer 220, and the magnetic conductive layer 220 corresponding to the second excitation layer 210 is the second magnetic conductive layer 220. The first permanent magnet 201 in the first excitation layer 210 inputs magnetic flux into the air gap 110. The magnetic flux passes through the air gap 110 and enters the first permanent magnet 201 in the second excitation layer 210. The magnetic flux is then concentrated by the second magnetic conductive layer 220 and flows back into the first excitation layer 210. The magnetic flux then passes through the air gap 110 and enters the first excitation layer 210. After passing through the magnetic concentration of the first magnetic conductive layer 220, the magnetic flux enters the first excitation layer 210 again, thereby forming a magnetic circuit.

[0043] See also Figure 1The coreless rotor structure 100 provided in the embodiment of the present application plays the role of the rotor yoke iron core through the two magnetic conductive layers 220. The two magnetic conductive layers 220 not only have the effect of concentrating magnetic field and avoiding magnetic leakage, but also the two magnetic conductive layers 220 simultaneously enhance the magnetic flux entering the air gap 110 through their own magnetic field, playing an excitation role. As a result, the coreless rotor structure 100 not only has the characteristics of low torque pulsation, low vibration noise, torque linearity, no core loss, no magnetic saturation problem, etc., but also can improve torque density and avoid magnetic leakage.

[0044] Optionally, the first permanent magnet 201 and the second permanent magnet 202 are both fan-shaped, and a plurality of first permanent magnets 201 are spliced ​​together to form a ring shape, and a plurality of second permanent magnets 202 can also be spliced ​​together to form a ring shape.

[0045] See also Figure 1 In some embodiments, the magnetization directions of any two adjacent first permanent magnets 201 are opposite, and the adjacent portions are covered by the second permanent magnet 202. The second permanent magnet 202 enables magnetic conduction between the two adjacent first permanent magnets 201. It is understood that the first permanent magnets 201 are arranged circumferentially, and of any two adjacent first permanent magnets 201, one first permanent magnet 201 inputs magnetic flux into the air gap 110, while the other first permanent magnet 201 inputs magnetic flux into the corresponding second permanent magnet 202. This allows the magnetic flux to form a loop between the two excitation and magnetic permeability components 200, thereby improving the uniformity of the magnetic field within the air gap 110.

[0046] In some embodiments, the edges of any two adjacent first permanent magnets 201 are butted together and the butt joint line evenly divides the corresponding second permanent magnets 202 along the axial direction of the rotor shaft, so that the magnetic flux of one of the first permanent magnets 201 can better enter the second permanent magnet 202 and then be conducted to the other first permanent magnet 201 through the second permanent magnet 202.

[0047] See also Figure 1 In some embodiments, the magnetization directions of any two adjacent second permanent magnets 202 are opposite. It is understood that the second permanent magnets 202 are circumferentially arranged on the corresponding excitation layer 210, and a corresponding first permanent magnet 201 is arranged at the adjacent position of any two adjacent second permanent magnets 202. The adjacent position of the two second permanent magnets 202 evenly divides the corresponding first permanent magnet 201 along the axial direction of the rotor shaft 205, and the magnetic flux is concentrated by the second permanent magnets 202 and re-input into the first permanent magnet 201.

[0048] In some embodiments, the two excitation layers 210 are arranged in an array along the axial direction of the rotor shaft 205, and the two first permanent magnets arranged in any array have the same magnetization direction. The first permanent magnets 201 at corresponding positions on the two excitation layers 210 have the same magnetization direction, so that magnetic flux can form a magnetic circuit between the two excitation layers 210.

[0049] In some embodiments, the two magnetic conductive layers 220 are mirror-imaged relative to the stator structure 300, and the magnetization directions of the two second permanent magnets in any mirror-image arrangement are opposite, so that the magnetic conductive layer 220 can concentrate the magnetic flux and input the magnetic flux into the corresponding excitation layer 210 to form a magnetic circuit.

[0050] See also Figure 2 In some embodiments, the magnetic conductive layer 220 further includes a third permanent magnet 203, which is located between the two second permanent magnets 202, and the magnetization direction of the third permanent magnet 203 is along the axial direction of the rotor shaft 205, and at least two of the third permanent magnets 203 have opposite magnetization directions.

[0051] See also Figure 2 It can be understood that, by providing the third permanent magnet 203 , the magnetic flux leakage at the magnetic conductive layer 220 can be reduced, and the magnetic flux input to the air gap 110 of the excitation layer 210 can be enhanced.

[0052] In some embodiments, the magnetization directions of any two adjacent third permanent magnets 203 are opposite.

[0053] See also Figure 4 It can be understood that by adjusting the height H of the first permanent magnet 201 and / or the second permanent magnet 202 along the magnetization direction M , wherein the height of the first permanent magnet 201 is represented as H1, the height of the second permanent magnet 202 is represented as H2, and the width W of the second permanent magnet 202 and / or the third permanent magnet 203 along the circumferential tangential magnetization direction is adjusted M , wherein the width of the second permanent magnet 202 is represented as W2, and the width of the third permanent magnet 203 is represented as W3. The output parameters of the coreless rotor structure 100 can be adjusted to form a coreless rotor structure 100 with different structures.

[0054] See also Figure 3 In some embodiments, the excitation magnetic conductive component 200 further includes an end cover 204 , and the end cover 204 is disposed on the magnetic conductive layer 220 .

[0055] Optionally, the end cover 204 is made of a non-iron core material, such as a plastic material. By providing the end cover 204 , the excitation layer 210 and the magnetic conductive layer 220 can be fixed, thereby improving stability during the rotation process.

[0056] In some embodiments, the end cover 204 is provided with a plurality of positioning grooves 207 arranged circumferentially along the rotor shaft 205, and each second permanent magnet 202 is respectively disposed in each positioning groove 207. Each positioning groove 207 is arranged around the circumference of the rotor shaft 205. By respectively installing each second permanent magnet 202 in each positioning groove 207, stability during operation is improved.

[0057] See also Figure 3 Optionally, a plurality of partitions 206 may be spaced apart on the end cover 204 , and any two adjacent partitions 206 and the end cover 204 body jointly define a positioning groove 207 .

[0058] The present application also proposes a permanent magnet motor, which includes an ironless rotor structure 100. The specific structure of the ironless rotor structure 100 refers to the above embodiment. Since the present permanent magnet motor adopts all the technical solutions of all the above embodiments, it also has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here.

[0059] See also Figure 8 In some embodiments, the permanent magnet motor further includes the stator structure 300, and the stator structure 300 includes a coil winding 302 and a fixing member 301. It is understandable that the coil winding 302 is made of copper wire, and the material of the fixing member 301 can be an iron core material or a non-iron core material. In this embodiment, the fixing member 301 is made of a non-iron core material. In other embodiments, the material can be selected according to actual conditions and is not limited here. It is understandable that due to the adoption of the above-mentioned coreless rotor structure 100, the permanent magnet motor of the present application has many characteristics such as high torque density, low torque pulsation, low loss, low electromagnetic vibration noise, and no torque nonlinearity caused by magnetic saturation.

[0060] See also Figures 1 to 3 The permanent magnet motor provided in the embodiment of the present application has no iron core material inside, and the internal magnetic circuit of the permanent magnet motor is constructed by the first permanent magnet 201, the second permanent magnet 202 and the third permanent magnet 203. The permanent magnet motor has a dual-rotor, single-stator structure 300, and each excitation magnetic conductive component 200 of the permanent magnet motor includes an excitation layer 210 at the end near the air gap 110 and a magnetic conductive layer 220 at the end far from the air gap 110. Among them, the first permanent magnet 201 at the end near the air gap 110 is axially magnetized and is responsible for providing magnetic flux to the air gap 110; the magnetization direction of the second permanent magnet 202 at the end far from the air gap 110 is circumferential tangential magnetization, or a combination of tangential magnetization and axial magnetization, and is responsible for providing a yoke magnetic flux circuit while increasing the excitation magnetic source.

[0061] See also Figures 1 to 3Optionally, the pole arc coefficients (the ratio of permanent magnets to a single magnetic pole) of the first permanent magnet 201, the second permanent magnet 202, and the third permanent magnet 203 in the permanent magnet motor can be adjusted, and are not limited to the exemplary structure of this embodiment. Specifically, the magnetic permeable layer 220 can use a Halbach structure in which the second permanent magnet 202 and the third permanent magnet 203 conform, or a structure in which only tangential magnetization is used. The pole arc coefficients of the second permanent magnet 202 and the third permanent magnet 203 can also be adjusted to obtain maximum torque output.

[0062] Optionally, the coreless rotor structure 100 can be used not only for coreless permanent magnet motors, but also for permanent magnet motors with iron cores in the stator, thereby increasing the magnetic density of the air gap 110 and thus increasing the output torque, thereby expanding the scope of use of the coreless rotor structure 100.

[0063] It is understood that the permanent magnet motor provided in this application does not contain any iron core material, and therefore does not generate cogging torque, resulting in smaller torque ripple and significantly reducing vibration and noise caused by the electromagnetic force of the iron core. In addition, the lack of iron core material means that there is no core loss and no iron core magnetic saturation problem.

[0064] See also Figures 5 to 7 Alternatively, to improve the torque density of the coreless permanent magnet motor, the present application proposes an axial magnetic flux structure with a dual rotor and a single stator. Since the dual rotors jointly excite the air gap 110, the magnetic flux density of the air gap 110 is increased. Alternatively, the double-layer permanent magnet array with different magnetization directions proposed in the present application can directly form a magnetic circuit inside the permanent magnet motor, so that multiple permanent magnets are jointly excited in the magnetic circuit, thereby significantly increasing the magnetic flux density of the air gap 110 and improving the output torque.

[0065] See also Figure 5 , the permanent magnet magnetic circuit inside the permanent magnet motor of this application is equivalent to Figure 5 , after the magnetic flux generated by the axially upward / downward magnetized first permanent magnet 201 enters the air gap 110, it first enters the same direction magnetized permanent magnet, and then enters the adjacent axially downward / upward magnetized permanent magnet after passing through the tangential magnetization of the rotor yoke permanent magnet, and then similarly passes through the air gap 110, the axially magnetized permanent magnet, and the tangentially magnetized permanent magnet, and finally returns to form a loop. It can be understood that there are a total of permanent magnet magnetic source magnetization in the above-mentioned magnetic circuit, and it is difficult to form a leakage magnetic circuit on other paths of the permanent magnet motor. Therefore, the coreless rotor structure 100 can provide a larger magnetic flux to the air gap 110, thereby improving the torque density of the permanent magnet motor.

[0066] See also Figures 5 to 7Optionally, in order to compare the magnetic field concentration effect of the permanent magnet motor of the present application, the present structure is compared with the rotor yoke-less structure (without iron core) and the rotor yoke-containing iron core structure in principle, and a comparison diagram of the equivalent magnetic circuits of the three structures of permanent magnet motors is provided. It is also noted that the excitation layer 210 and the magnetic conductive layer 220 in the present application, that is, the pole arc coefficients of the first permanent magnet 201 at the end entering the air gap 110 and the second permanent magnet 202 away from the air gap 110 are both 1, that is, the first permanent magnet 201 and the second permanent magnet 202 are fully covered with magnetic poles.

[0067] See also Figures 6 and 7 Alternatively, in a yokeless structure, since the yoke is made of air, most of the permanent magnet's magnetomotive force is consumed in the yoke's magnetic resistance, significantly reducing the magnetomotive force of the air gap 110. In contrast, in a yoke-containing iron core structure, although the iron core has an extremely high magnetic permeability and the yoke hardly consumes the permanent magnet's magnetomotive force, there is no additional second permanent magnet 202 to provide a magnetizing effect. Therefore, under the same parameters, the air gap 110 magnetic flux density of the iron core rotor structure is lower than the air gap 110 density of the iron coreless rotor structure 100 provided in this application.

[0068] The above are merely optional embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included within the scope of the claims of the present application.

Claims

1. A coreless rotor structure, matched with a stator structure, characterized in that: The coreless rotor structure includes: a rotor shaft and an excitation magnetic conductive component, the excitation magnetic conductive component includes an excitation layer and a magnetic conductive layer arranged on the excitation layer, the stator structure, the excitation layer and the magnetic conductive layer are arranged in sequence along the axial direction of the rotor shaft, the excitation layer includes a plurality of first permanent magnets that are magnetized along the axial direction of the rotor shaft, and the magnetization directions of at least two of the first permanent magnets are opposite, the magnetic conductive layer includes a plurality of second permanent magnets that are magnetized along the circumferential direction, each of the first permanent magnets is arranged along the circumference of the rotor shaft, and the second permanent magnet is used for magnetic conduction between two adjacent first permanent magnets with opposite magnetization directions, two excitation magnetic conductive components are arranged, the stator structure is located between the two excitation layers, and a magnetic circuit is formed between the two excitation magnetic conductive components.

2. The coreless rotor structure according to claim 1, wherein: The magnetization directions of any two adjacent first permanent magnets are opposite, and the adjacent portions are both covered by the second permanent magnet.

3. The coreless rotor structure according to claim 2, wherein: The edges of any two adjacent first permanent magnets are butted against each other, and the butting line equally divides the corresponding second permanent magnet along the axial direction of the rotor shaft.

4. The coreless rotor structure according to claim 1, wherein: The magnetization directions of any two adjacent second permanent magnets are opposite.

5. The coreless rotor structure according to claim 1, wherein: The two excitation layers are arranged in an array along the axial direction of the rotor shaft, and the magnetization directions of the two first permanent magnets arranged in any array are the same.

6. The coreless rotor structure according to claim 1, wherein: The two magnetic conductive layers are arranged in a mirror image relative to the stator structure, and the magnetization directions of the two second permanent magnets in any mirror image arrangement are opposite.

7. The coreless rotor structure according to any one of claims 1 to 6, characterized in that: The magnetic conductive layer further includes a third permanent magnet, which is located between the two second permanent magnets, and a magnetization direction of the third permanent magnet is along the axial direction of the rotor shaft.

8. The coreless rotor structure according to claim 7, wherein: The magnetization directions of any two adjacent third permanent magnets are opposite.

9. The coreless rotor structure according to any one of claims 1 to 6, wherein: The excitation magnetic conductive component further includes an end cover, which is arranged on the magnetic conductive layer. The end cover is provided with a plurality of positioning grooves arranged along the circumference of the rotor shaft, and each of the second permanent magnets is respectively arranged in each of the positioning grooves.

10. A permanent magnet motor, characterized in that: The permanent magnet motor comprises the coreless rotor structure according to any one of claims 1 to 9, and further comprises the stator structure, wherein the stator structure comprises a fixing member and a coil winding arranged on the stator fixing member.

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