Outer rotor structure and motor
By using a support ring structure in the external rotor motor, the problems of complex assembly and low output capacity are solved, achieving efficient assembly and stable operation, improving torque density, and reducing motor vibration and noise.
Patent Information
- Application Number
- CN202511318216.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-15
- Publication Date
- 2026-01-27
AI Technical Summary
The existing external rotor motor has low assembly efficiency, low output capacity and low torque density, mainly due to the large number of magnetic pole partitions, which leads to complex assembly, and the fixed ring, which increases magnetic resistance and affects output capacity.
The structure adopts a support ring, which is equipped with a limiting protrusion and a limiting groove. The permanent magnet is embedded in the limiting groove, and the support ring is embedded in the mating gap between the permanent magnets. The support ring is made of non-magnetic material to avoid increasing magnetic resistance.
It improves motor assembly efficiency, prevents permanent magnets from falling off, ensures output capacity and torque density, and reduces motor vibration and noise.
Smart Images
Figure CN121417541A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of motor technology, and more specifically, to an external rotor structure and a motor. Background Technology
[0002] Currently, the non-full-pole arc arrangement of permanent magnets in external rotor motors can effectively reduce motor vibration and noise, and lower motor costs. However, there are gaps between the permanent magnets in motors with non-full-pole arc arrangements. Existing technologies mainly address this by adding magnetic pole spacers of the same size between adjacent permanent magnets to ensure uniform distribution, or by using fixing rings between the permanent magnets and the yoke to fix multiple independent permanent magnets. However, the number of magnetic pole spacers required is the same as the number of permanent magnets. A large number of pole spacers leads to complex motor assembly and low assembly efficiency. Furthermore, the fixing rings increase the magnetic resistance between the permanent magnets and the yoke, resulting in low maximum torque output and low torque density. Summary of the Invention
[0003] The main objective of this invention is to provide an external rotor structure and motor to at least solve the problems of low motor assembly efficiency, low output capacity, and low torque density.
[0004] According to one aspect of the present invention, an external rotor structure is provided, comprising:
[0005] A ring-shaped body, wherein multiple permanent magnets are spaced apart on the inner peripheral sidewall of the ring-shaped body, and there is a fitting gap between two adjacent permanent magnets;
[0006] A support ring is provided on the side of the permanent magnet away from the annular body. The support ring has a plurality of limiting protrusions spaced apart in the circumferential direction. A limiting groove for placing the permanent magnet is formed between adjacent limiting protrusions. The limiting groove is embedded in the mating gap.
[0007] Furthermore, along the radial direction of the support ring, the width of the limiting protrusion at the end near the annular body is greater than the width of the limiting protrusion at the end away from the annular body, so as to limit the radial displacement of the permanent magnet.
[0008] Furthermore, the width of the limiting protrusion gradually increases along the radial direction of the support ring and in the direction close to the annular body.
[0009] Furthermore, along the radial direction of the support ring, the depth d1 of the limiting groove and the thickness d of the permanent magnet satisfy the following relationship: d / 2≤d1≤d.
[0010] Furthermore, along the axial direction of the support ring, the width L1 of the support ring and the length L of the permanent magnet satisfy the following relationship: L / 3≤L1≤L.
[0011] Furthermore, along the axial direction of the annular body, the support ring is disposed in the middle of the permanent magnet.
[0012] Furthermore, the outer rotor structure includes at least one of the support rings; wherein, when the outer rotor structure includes multiple support rings, the multiple support rings are arranged along the axial direction of the annular body.
[0013] Furthermore, the support ring includes a strip structure extending circumferentially along the annular body;
[0014] The strip structure is integrally formed; or...
[0015] The strip structure includes a first connecting end and a second connecting end, wherein the first connecting end and the second connecting end are fixedly connected or detachably connected.
[0016] Furthermore, the permanent magnet is configured with an arc-shaped structure on the side closest to the annular body, and the permanent magnet is attached to the inner peripheral sidewall of the annular body through the arc-shaped structure.
[0017] Furthermore, the support ring is a non-magnetic structure made of a non-magnetic material, which includes a magnetic material obtained by demagnetization.
[0018] Furthermore, the non-magnetic material includes aluminum alloy, plastic, or demagnetized stainless steel.
[0019] On the other hand, the present invention also provides an electric motor that includes the above-described external rotor structure.
[0020] In this invention, limiting protrusions are spaced circumferentially on the support ring, and limiting grooves are formed between adjacent limiting protrusions to accommodate permanent magnets. These grooves fix the permanent magnets in place, and the limiting protrusions are embedded in the mating gaps between adjacent permanent magnets, ensuring the permanent magnets are tightly attached to the inner circumferential sidewall of the annular body, preventing them from falling off or shifting. The support ring can simultaneously fix all permanent magnets inside the annular body, eliminating the cumbersome assembly process required when using magnetic separators between adjacent permanent magnets, significantly improving motor assembly efficiency. It also ensures uniform circumferential distribution and consistent gap dimensions of the permanent magnets along the annular body, reducing motor vibration and noise. The support ring is located on the side of the permanent magnets away from the annular body. The inner wall of the limiting grooves provides radial support and circumferential limiting for the permanent magnets, dispersing the radial force borne by the permanent magnets during motor operation, preventing the risk of permanent magnets falling off, and not increasing the magnetic resistance between the permanent magnets and the yoke, thus ensuring the motor's output capacity and torque density. Attached Figure Description
[0021] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:
[0022] Figure 1 This is a three-dimensional structural diagram of the external rotor structure disclosed in an embodiment of the present invention;
[0023] Figure 2 This is a schematic diagram of the assembly of the permanent magnet and the support ring of the external rotor structure disclosed in an embodiment of the present invention;
[0024] Figure 3 This is a plan view of the assembly of the permanent magnet and the support ring of the external rotor structure disclosed in an embodiment of the present invention;
[0025] Figure 4 for Figure 3 Enlarged diagram of A in the middle;
[0026] Figure 5 This is a partial schematic diagram of the external rotor structure disclosed in an embodiment of the present invention;
[0027] Figure 6 for Figure 5 Enlarged diagram of B in the middle;
[0028] Figure 7 This is a partial schematic diagram of the support ring of the external rotor structure disclosed in an embodiment of the present invention;
[0029] Figure 8 for Figure 7 An enlarged diagram of C in the diagram.
[0030] The above figures include the following reference numerals:
[0031] 10. Ring-shaped main body; 20. Permanent magnet; 21. Fitting gap; 30. Support ring; 31. Limiting groove; 32. Limiting protrusion; 321. Predetermined gap; 33. First connecting end; 34. Second connecting end. Detailed Implementation
[0032] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.
[0033] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.
[0034] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.
[0035] In related technologies, permanent magnets in motors with non-full-pole arc arrangement have a certain gap between them. This is mainly achieved by embedding magnetic pole spacers between adjacent permanent magnets, or by setting fixing rings between permanent magnets and yokes to fix multiple permanent magnets simultaneously, thus ensuring the uniform distribution and fixation of the permanent magnets. However, the method using magnetic pole spacers requires a large number of spacers, leading to complex motor assembly, low assembly efficiency, and the permanent magnets being subjected to radial forces during assembly or operation, posing a risk of permanent magnet detachment. The method using fixing rings increases the magnetic reluctance between the permanent magnet and the yoke, thereby reducing the motor's output capacity. Therefore, this application provides an external rotor structure and motor. This external rotor structure is provided with a support ring, which has alternating limiting grooves and limiting protrusions. The permanent magnets are embedded in the limiting grooves, and the limiting protrusions are embedded in the mating gaps, allowing the support ring to fix the permanent magnets, improving the motor assembly efficiency and avoiding the risk of permanent magnet detachment during motor operation.
[0036] See Figures 1 to 8As shown, according to an embodiment of this application, an external rotor structure is provided, including an annular body 10, permanent magnets 20, and a support ring 30. Multiple permanent magnets 20 are spaced apart on the inner circumferential sidewall of the annular body 10, with a fitting gap 21 between adjacent permanent magnets 20. The support ring 30 is located on the side of the permanent magnets 20 away from the annular body 10, and multiple limiting protrusions 32 are spaced apart circumferentially on the support ring 30. A limiting groove 31 for placing the permanent magnets 20 is formed between adjacent limiting protrusions 32, and the limiting protrusions 32 are embedded within the fitting gap 21.
[0037] It is understood that when the outer rotor structure is assembled into the outer rotor motor in the embodiments of this application, the outer rotor structure is sleeved on the outer periphery of the stator. The permanent magnet 20 of the outer rotor structure can generate a rotating magnetic field after the winding of the stator is energized, and generate electromagnetic torque on the outer rotor structure, thereby driving the outer rotor structure to rotate relative to the stator.
[0038] In this embodiment, the annular body 10 is configured as a rotor yoke with an outer rotor structure. Multiple permanent magnets 20 are spaced apart along the inner circumferential sidewall of the annular body 10, and a support ring 30 ( Figures 1 to 6 , Figure 8 In the red section, among the multiple limiting protrusions 32 spaced circumferentially, any two adjacent limiting protrusions 32 form a limiting groove 31. The permanent magnet 20 is fixed within the limiting groove 31. The multiple limiting grooves 31, spaced circumferentially along the support ring 30, can fix the multiple permanent magnets 20 one by one in the circumference of the annular body 10. Furthermore, the limiting protrusions 32 are embedded in the mating gaps 21 between adjacent permanent magnets 20, thus preventing the permanent magnets 20 from falling off or shifting, improving the stability of motor operation. In this embodiment, the support ring 30 can simultaneously fix all the permanent magnets 20 on the inner circumferential sidewall of the annular body 10, eliminating the need for separate magnetic pole partitions between adjacent permanent magnets 20. This makes motor assembly more convenient and significantly improves assembly efficiency. The permanent magnets 20 are evenly distributed on the inner circumferential sidewall of the annular body 10, ensuring motor performance. The support ring 30 does not increase the magnetic resistance between the permanent magnets 20 and the yoke, ensuring the motor's output capacity. The support ring 30 can provide a radial force to the permanent magnet 20 toward the annular body 10, ensuring that the permanent magnet 20 will not fall off when subjected to a radial force toward the inside of the annular body 10 during motor operation.
[0039] Furthermore, along the radial direction of the support ring 30, the width of the end of the limiting protrusion 32 near the annular body 10 is greater than the width of the end of the limiting protrusion 32 away from the annular body 10, so as to limit the radial displacement of the permanent magnet 20. Thus, when the limiting protrusion 32 is embedded in the mating gap 21 between adjacent permanent magnets 20, the end of the limiting protrusion 32 near the annular body 10 can abut against the permanent magnets 20 on both sides, preventing the permanent magnets 20 from moving radially along the support ring 30, and ensuring that the permanent magnets 20 can be fixed in the limiting groove 31.
[0040] Preferred, Reference Figure 8 As shown, along the radial direction of the support ring 30 and close to the annular body 10 (e.g.) Figure 8 (In the direction indicated by the middle arrow x1), the width s2 of the limiting protrusion 32 gradually increases.
[0041] In this embodiment, by setting the width of the limiting protrusion 32 to gradually increase along the radial direction of the support ring 30 and in the direction close to the annular body 10, the limiting groove 31 can form a trapezoidal structure. The side of the trapezoidal structure close to the annular body 10 is the long side, and the side away from the annular body 10 is the short side. In this way, when the permanent magnet 20 is assembled in the limiting groove 31, the limiting protrusion 32 can be locked in the mating gap 21 between two adjacent permanent magnets 20 and abut against the permanent magnets 20 on both sides, so as to ensure that the permanent magnet 20 can be better fixed on the inner side of the annular body 10. Correspondingly, since the limiting groove 31 in this embodiment is formed by adjacent limiting protrusions 32, the width of the limiting groove 31 gradually increases along the radial direction of the support ring 30 and close to the annular body 10, so that the permanent magnet 20 can achieve an interference fit with the limiting groove 31, so that the permanent magnet 20 can be stably embedded in the limiting groove 31, ensuring that the permanent magnet 20 and the support ring 30 will not separate when the motor is running at high speed, thus improving the reliability of motor operation.
[0042] refer to Figure 6 and Figure 8As shown, along the radial direction of the support ring 30, the depth d1 of the limiting protrusion 32 and the thickness d of the permanent magnet 20 satisfy the relationship: d / 2 ≤ d1 ≤ d. Thus, by setting the depth d1 of the limiting protrusion 32 along the radial direction of the support ring 30 to be greater than or equal to half the thickness d of the permanent magnet 20 and less than or equal to the thickness d of the permanent magnet 20, when the depth d1 of the limiting protrusion 32 is less than half the thickness d of the permanent magnet, only a small portion of the permanent magnet 20 is embedded in the limiting groove 31. That is, the gap between the support ring 30 and the annular body 10 is too large, and the limiting groove 31 cannot effectively fix the permanent magnet 20. During high-speed operation of the motor, the support ring 30 may detach from the permanent magnet. When the depth d1 of the limiting groove 31 is greater than the thickness d of the permanent magnet 20, a certain gap may exist between the permanent magnet 20 and the annular body 10, making it impossible to effectively support the permanent magnet 20.
[0043] In one embodiment, when d1 = d, the limiting protrusion 32 fits against the inner side of the annular body 10. At this time, the annular body 10 directly supports the support ring 30 in the circumferential direction, so that the support ring 30 can be stably fixed on the inner side of the annular body 10, which improves the fixing effect of the support ring 30 on the permanent magnet 20 and improves the reliability of motor operation.
[0044] In one embodiment, when d1 < d, there is a predetermined gap 321 between the limiting protrusion 32 and the inner peripheral sidewall of the annular body 10. The permanent magnet 20 is attached to the inner side of the annular body 10. At this time, the permanent magnet 20 serves as a support structure for the support ring 30, ensuring that the support ring 30 can effectively fix the permanent magnet 20 during motor operation, reducing the magnetic resistance between the permanent magnet 20 and the annular body 10 (yoke), and improving the maximum torque output capability and torque density of the motor.
[0045] It should be noted that the depth d1 of the limiting protrusion 32 in this embodiment can be set according to actual conditions. For example, d1 can be set to 0.5d, 0.6d, 0.7d, 0.8d, 0.9d, or d. Specifically, this application does not limit this.
[0046] refer to Figure 4As shown, along the axial direction of the support ring 30, the width L1 of the support ring 30 and the length L of the permanent magnet 20 satisfy the relationship: L / 3 ≤ L1 ≤ L. Thus, setting the width L1 of the support ring 30 along the axial direction to be greater than or equal to one-third of the length of the permanent magnet 20 and less than or equal to the length L of the permanent magnet 20 ensures the support and fixation effect of the support ring 30 on the permanent magnet 20. For example, when the width L1 of the support ring 30 is less than one-third of the length L of the permanent magnet 20, the portion of the permanent magnet 20 extending beyond the support ring 30 is too long, and during motor operation, it is prone to detachment or displacement due to inertia due to the lack of a supporting and fixing structure. When the width L1 of the support ring 30 is greater than the length L of the permanent magnet 20, the width L1 of the support ring 30 is too large, resulting in material waste and increased weight of the outer rotor structure. Furthermore, a portion of the support ring 30 will protrude from the permanent magnet 20, which will affect the assembly of the outer rotor structure.
[0047] More preferably, the width L1 of the support ring 30 is set to: L / 3≤L1≤L / 2. In this way, the width of the support ring 30 is set to one-third to one-half of the length L of the permanent magnet 20, which can not only ensure the fixing effect of the permanent magnet 20, but also reduce the material weight of the support ring 30 and reduce the production cost of the motor.
[0048] It should be noted that the width L1 of the support ring 30 along its own axis in this embodiment can be set according to actual conditions. For example, L1 can be set to 0.4L, 0.45L, or 0.5L. Specifically, this application does not limit this.
[0049] Furthermore, the support ring 30 is a non-magnetic structure made of a non-magnetic material, which includes materials obtained by demagnetizing magnetic materials. It is understood that the non-magnetic material in this embodiment includes not only materials with zero permeability, but also materials with permeability much lower than that of strongly magnetic materials (e.g., iron, silicon steel sheets). In this embodiment, the non-magnetic material includes not only materials that are inherently non-magnetic, but also materials obtained by demagnetizing magnetic materials; for example, magnetic stainless steel can be heat-treated to obtain non-magnetic stainless steel.
[0050] Preferably, the non-magnetic material in this embodiment includes aluminum alloy, plastic, or demagnetized stainless steel. By using non-magnetic materials such as aluminum alloy, plastic, or demagnetized stainless steel for the support ring 30, no additional magnetic path is formed in the motor stator, avoiding stray magnetic losses caused by magnetic field shunting of the permanent magnet 20, ensuring motor torque output, and improving motor reliability. Stainless steel has high rigidity and corrosion resistance, making it suitable for high-speed, high-load applications. Aluminum alloy can significantly reduce the weight of the outer rotor structure, reducing inertial resistance and vibration noise, meeting the lightweight requirements of the motor. Plastic offers low cost, high molding precision, and insulation, avoiding electrochemical corrosion and being easy to process.
[0051] Furthermore, along the axial direction of the annular body 10, a support ring 30 is disposed at the center of the permanent magnet 20. Thus, by placing the support ring 30 at the center of the permanent magnet 20 along the axial direction of the annular body 10, the support ring 30 can apply a supporting force to the center of the permanent magnet 20 in the axial direction of the annular body 10, preventing the permanent magnet 20 from being unsupported at one end and prone to detachment. This centering and limiting of the permanent magnet 20 allows it to effectively resist the inertia and electromagnetic force during motor operation, preventing the permanent magnet 20 from radially detaching or circumferentially shifting. When the support rings 30 are placed at both ends of the permanent magnet 20 along the axial direction of the annular body 10, if there is only one support ring 30 and the width of the support ring 30 is small, a large part of one end of the permanent magnet 20 will not be supported and fixed by the support rings 30. As a result, when the motor is running at high speed, the part of the permanent magnet 20 that is not fixed by the support rings 30 is prone to falling off or shifting, which may further cause the entire permanent magnet 20 to fall off or shift, reducing the reliability of the motor. Therefore, in this embodiment, the support rings 30 are placed in the middle of the permanent magnet 20, which can improve the reliability of the motor.
[0052] Furthermore, the outer rotor structure includes at least one support ring 30. That is, the outer rotor structure can have one support ring 30, two support rings 30, or even other numbers of support rings 30.
[0053] It should be noted that the number of support rings in this embodiment can be selected according to the actual situation. For example, the number of support rings 30 can be one, two or three, as long as they can effectively and reliably fix and support the permanent magnet 20. This application does not limit this.
[0054] When the outer rotor structure includes multiple support rings 30, these support rings 30 are arranged along the axial direction of the annular body 10. In this way, the multiple support rings 30 are arranged sequentially, ensuring that each support ring 30 can support and fix the permanent magnet 20. Different support rings 30 fix the permanent magnet 20 at different positions. When the size of the support ring 30 is small and the size of the permanent magnet 20 is large, a single support ring 30 cannot effectively support and fix the permanent magnet 20. Therefore, setting multiple support rings 30 along the axial direction of the annular body 10 to support and fix the permanent magnet 20 avoids the risk of the permanent magnet 20 falling off or shifting, and eliminates the need to redesign and manufacture large-sized support rings 30, thus improving the economic efficiency of motor production.
[0055] Furthermore, the support ring 30 includes a strip structure extending circumferentially along the annular body 10. Thus, designing the support ring 30 as a strip structure extending circumferentially along the annular body 10 allows for better adaptation to the permanent magnets 20 arranged circumferentially along the annular body 10. This enables all permanent magnets 20 to be supported and fixed using a single support ring 30, improving the support effect, reducing the production cost of the motor, and simplifying assembly.
[0056] Preferably, the strip structure is integrally molded. This integral molding of the strip structure, such as through injection molding or stamping, significantly improves the structural strength and stability of the support ring 30. The seamless, one-piece molding prevents cracking, breakage, or detachment of the support ring 30 during high-speed motor operation due to weak joints, ensuring effective fixation of the support ring 30 to the permanent magnet 20.
[0057] Preferably, the strip structure includes a first connecting end 33 and a second connecting end 34, which are fixedly connected or detachably connected. The fixed connection includes welding, riveting, etc., while the detachable connection includes self-locking connection, snap-fit, and screw connection, etc. Thus, compared to a one-piece structure, configuring the strip structure with a first connecting end 33 and a second connecting end 34, and using a fixed or detachable connection for the first and second connecting ends 33 and 34, allows for easier assembly of the permanent magnet 20 during motor assembly. This simplifies the assembly of the permanent magnet 20, reduces the difficulty of motor assembly, and improves assembly efficiency.
[0058] Preferably, when a self-locking connection is used between the first connecting end 33 and the second connecting end 34, refer to Figure 8As shown, the first connecting end 33 can adopt an L-shaped structure, and the second connecting end can adopt a U-shaped structure. When the support ring 30 is assembled with the permanent magnet 20 and the annular body 10, the L-shaped structure abuts against the inner wall of the annular body 10, and the U-shaped structure presses against the L-shaped structure. Under the action of the support ring 30 as a whole and the permanent magnet 20, the side of the U-shaped structure abuts against the side of the L-shaped structure to achieve circumferential locking, and the bottom of the U-shaped structure abuts against the bottom of the L-shaped structure to achieve radial locking, so as to fix the first connecting end 33 and the second connecting end 34 of the strip structure.
[0059] Preferably, the permanent magnet 20 is configured with an arc-shaped structure on the side near the annular body 10, and the permanent magnet 20 is attached to the inner peripheral sidewall of the annular body 10 through the arc-shaped structure. In this way, the permanent magnet 20 and the magnetic yoke (annular body 10) are attached, which reduces the magnetic resistance between the permanent magnet 20 and the magnetic yoke, improves the maximum torque output capability of the motor, and makes the motor torque density higher.
[0060] Understandably, when setting the structure of the support ring 30 in this embodiment, the structure of the limiting groove 31 is determined by the shape of the permanent magnet 20 to ensure that the limiting groove 31 can reliably fix the permanent magnet 20. The structure of the limiting protrusion 32 is determined by the fitting gap 21 between adjacent permanent magnets 20, so that multiple permanent magnets 20 can be fixed simultaneously by the support ring 30, which has good manufacturability, improves the fixing effect of the permanent magnets 20, and improves the reliability of the motor.
[0061] Optionally, in this embodiment, the permanent magnet 20 near the annular body 10 can be configured as an arc-shaped structure. The arc-shaped structure can fit tightly against the inner circumferential sidewall of the annular body 10, increasing the contact area between the permanent magnet 20 and the annular body 10. This results in greater friction between the permanent magnet 20 and the annular body 10 in the circumferential direction during motor rotation, ensuring that the permanent magnet 20 will not fall off and improving the reliability of the motor.
[0062] On the other hand, this application also discloses an electric motor that includes the aforementioned outer rotor structure. Therefore, this electric motor incorporates all the technical advantages of the aforementioned outer rotor structure. Since the technical advantages of the rotor structure have already been described in detail above, they will not be repeated here.
[0063] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.
[0064] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.
[0065] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. An external rotor structure, characterized in that, include: A ring-shaped body (10) has multiple permanent magnets (20) spaced apart on its inner peripheral sidewall, with a fitting gap (21) between two adjacent permanent magnets (20). A support ring (30) is provided on the side of the permanent magnet (20) away from the annular body (10). The support ring (30) has a plurality of limiting protrusions (32) spaced apart in the circumferential direction. A limiting groove (31) for placing the permanent magnet (20) is formed between adjacent limiting protrusions (32). The limiting protrusions (32) are embedded in the mating gap (21).
2. The external rotor structure according to claim 1, characterized in that, Along the radial direction of the support ring (30), the width of the limiting protrusion (32) near the annular body (10) is greater than the width of the limiting protrusion (32) away from the annular body (10), so as to limit the radial displacement of the permanent magnet (20).
3. The external rotor structure according to claim 2, characterized in that, Along the radial direction of the support ring (30) and close to the annular body (10), the width of the limiting protrusion (32) gradually increases.
4. The external rotor structure according to claim 1, characterized in that, Along the radial direction of the support ring (30), the depth d1 of the limiting protrusion and the thickness d of the permanent magnet (20) satisfy the following relationship: d / 2≤d1≤d.
5. The external rotor structure according to claim 1, characterized in that, Along the axial direction of the support ring (30), the width L1 of the support ring (30) and the length L of the permanent magnet (20) satisfy the following relationship: L / 3≤L1≤L.
6. The external rotor structure according to any one of claims 1 to 5, characterized in that, The support ring (30) is a non-magnetic structure made of non-magnetic material, which includes a material obtained by demagnetizing a magnetic material.
7. The external rotor structure according to claim 6, characterized in that, The non-magnetic material includes aluminum alloy, plastic, or demagnetized stainless steel.
8. The external rotor structure according to claim 1, characterized in that, Along the axial direction of the annular body (10), the support ring (30) is disposed in the middle of the permanent magnet (20).
9. The external rotor structure according to claim 1, characterized in that, The outer rotor structure includes at least one of the support rings (30); When the outer rotor structure includes multiple support rings (30), the multiple support rings (30) are arranged along the axial direction of the annular body (10).
10. The external rotor structure according to claim 1, characterized in that, The support ring (30) includes a strip structure extending circumferentially along the annular body (10); The strip structure is integrally formed; or... The strip structure includes a first connecting end (33) and a second connecting end (34), wherein the first connecting end (33) and the second connecting end (34) are fixedly connected or detachably connected.
11. The external rotor structure according to claim 1, characterized in that, The permanent magnet (20) is configured with an arc-shaped structure on the side near the annular body (10), and the permanent magnet (20) is attached to the inner peripheral sidewall of the annular body (10) through the arc-shaped structure.
12. An electric motor, characterized in that, The external rotor structure includes any one of claims 1 to 11.