Rotor structure and its molding method and motor

Abstract

This invention provides a rotor structure, its molding method, and a motor. The rotor structure includes: a support frame (1), integrally injection molded from injection-molded permanent magnets, comprising a radial excitation source (3) and an axial excitation source (4). The axial excitation source (4) is located at both axial ends of the support frame (1) and is used to form an axial magnetic field. The radial excitation source (3) is disposed radially inside the axial excitation source (4) and is used to form a radial magnetic field. The radial excitation source (3) and the axial excitation source (4) form a first mounting groove (5); multiple radial plastic magnets (6) are arranged at intervals along the circumference of the support frame (1) within the first mounting groove (5), and a second mounting groove (22) is formed between adjacent radial plastic magnets (6); multiple tangential ferrites (2) are correspondingly disposed within the second mounting groove (22). According to the rotor structure of this invention, the assembly difficulty of the magnets can be reduced, ensuring the working performance and reliability of the motor.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and more specifically, to a rotor structure, its molding method, and a motor. Background Technology

[0002] With increasing global emphasis on energy conservation, emission reduction, and green energy, motor energy efficiency standards are constantly being raised, placing more stringent demands on the high efficiency and high torque density of permanent magnet motors. Due to their advantages such as high efficiency, high power density, and low noise, permanent magnet motors are widely used in home appliances, automobiles, and industrial drives. However, improving the performance of permanent magnet motors also faces technological challenges and limitations.

[0003] Traditional permanent magnet motors typically employ tangential or radial magnetization to create the necessary magnetic field. However, these methods have significant limitations in practical applications. With tangential magnetization, the magnetic field direction is perpendicular to the motor axis; with radial magnetization, it's parallel. Regardless of the method, the magnetic field is not completely enclosed in space, causing some magnetic field lines to "leak" at both ends of the motor axis, a phenomenon known as "magnetic leakage." This leakage not only reduces the effective magnetic flux of the permanent magnet and decreases the air gap magnetic flux density of the motor, but also degrades the material properties of the permanent magnet, directly impacting the motor's efficiency and torque density.

[0004] To address the problem of magnetic leakage and improve the utilization efficiency of permanent magnets, existing technologies have proposed a series of improvement schemes. One common approach is to add axial magnets at both ends of the motor. These axial magnets are magnetized axially. Theoretically, the addition of axial magnets can form a more closed magnetic circuit, thereby reducing magnetic leakage at both ends of the permanent magnet motor and improving the utilization efficiency of the permanent magnets.

[0005] However, this approach encountered new challenges during implementation. Due to the strong magnetic force between permanent magnets, when the magnetic poles of two magnets are the same, this magnetic force manifests as a repulsive force. When assembling axial magnets, the assembly process needs to overcome this repulsive force because of the potential magnetic pole repulsion between axial and tangential or radial magnets. This not only increases the assembly difficulty but also affects the final performance and reliability of the motor. Summary of the Invention

[0006] The main objective of this invention is to provide a rotor structure, its forming method, and a motor, which can reduce the assembly difficulty of magnets and ensure the working performance and reliability of the motor.

[0007] To achieve the above objectives, according to one aspect of the present invention, a rotor structure is provided, comprising:

[0008] The support frame is integrally injection molded from a permanent magnet. The support frame includes a tangential excitation source, a radial excitation source, and an axial excitation source. The axial excitation source is located at both ends of the support frame and is used to form an axial magnetic field. The tangential excitation source is used to form a tangential magnetic field. The radial excitation source is located on the radial inner side of the tangential excitation source and is used to form a radial magnetic field. The radial excitation source and the axial excitation source form a first mounting groove. The axial excitation source is located at both ends of the tangential excitation source and is used to form an axial magnetic field. The mounting groove is formed between adjacent tangential excitation sources.

[0009] Radial plastic magnets, multiple radial plastic magnets are arranged at intervals along the circumference of the support frame in the first mounting groove, and a second mounting groove is formed between adjacent radial plastic magnets. Each radial plastic magnet is correspondingly set in a mounting groove. The radial plastic magnets are formed by stacking rotor laminations.

[0010] Tangential ferrites are used to form a tangential magnetic field, and multiple tangential ferrites are arranged one-to-one in the second mounting slot.

[0011] Furthermore, there is an assembly gap between the tangential ferrite and the radial plastic magnet, and the support frame also includes an injection-molded connecting layer integrally injection-molded with the radial excitation source and the axial excitation source, the injection-molded connecting layer filling the assembly gap.

[0012] Furthermore, the radial outer side of the radial plastic magnet protrudes to both sides along the circumferential direction to form a first lateral protrusion, which stops on the radial outer side of the tangential ferrite.

[0013] Furthermore, the radial plastic magnet is made by melting.

[0014] Furthermore, radial plastic magnets include strontium ferrite, barium ferrite, and nylon.

[0015] Furthermore, the radial plastic magnet is radially magnetized, and the radial outer polarity of the radial plastic magnet is the same as the magnetism of the circumferentially adjacent excitation source on the side facing the radial plastic magnet.

[0016] Furthermore, the tangential ferrite is made of plastic magnetic ferrite particles.

[0017] Furthermore, the thickness of the injection-molded bonding layer is 0.05mm to 0.2mm.

[0018] Furthermore, the support frame also includes an axial connection portion, which is axially connected between the two axial excitation sources and is located on the radially outer side of the tangential ferrite.

[0019] Furthermore, the radially outer side of the axial connection protrudes to both sides in the circumferential direction to form a second lateral protrusion, and the second lateral protrusion stops the radially outer side of the first lateral protrusion.

[0020] Furthermore, the rotor structure also includes an inner rotor core and damping rubber. The support frame has mounting through holes. Multiple first protrusions are spaced apart circumferentially on the inner wall of the mounting through holes. Second protrusions are spaced apart circumferentially on the outer peripheral wall of the inner rotor core. A first groove is formed between adjacent first protrusions, and a second groove is formed between adjacent second protrusions. The first protrusions are disposed in the second grooves and form a filling gap with the inner wall of the second grooves. The second protrusions are disposed in the first grooves and form a filling gap with the inner wall of the first grooves. The damping rubber fills the filling gaps.

[0021] Furthermore, a first positioning hole is provided through the radial plastic magnet along the axial direction. The first positioning hole is a non-circular hole and is filled with damping adhesive. And / or, an injection hole is provided on the inner rotor core along the axial direction and is filled with damping adhesive.

[0022] Furthermore, both the first positioning hole and the injection hole are filled with damping adhesive, and damping adhesive is provided on the outer end face of the axial excitation source. A flow hole is provided on the axial excitation source in a circumferential manner corresponding to the first positioning hole. The damping adhesive flows into the first positioning hole through the flow hole. The first positioning hole, the injection hole, the outer end face of the axial excitation source and the damping adhesive in the flow hole are an integral structure, and the damping adhesive forms a cage-like structure.

[0023] Furthermore, the sides of the first protrusion are parallel to the corresponding sides of the second groove, and the sides of the second protrusion are parallel to the corresponding sides of the first groove.

[0024] Furthermore, the damping rubber filling the gaps is continuous circumferentially, isolating and connecting the support frame and the inner rotor core.

[0025] Furthermore, the inner rotor core has a central shaft hole, and a second positioning hole is provided on the inner wall of the central shaft hole to position the circumferential relative position of the inner rotor core and the support frame.

[0026] Furthermore, the radial outer side of the tangential ferrite protrudes to both sides in the circumferential direction to form a second lateral protrusion, which stops on the radial outer side of the radial plastic magnet.

[0027] Furthermore, the tangential ferrite, radial excitation source, and axial excitation source have the same polarity when formed on the same radial plastic magnet, and the polarities of two adjacent radial plastic magnets along the circumferential direction are opposite.

[0028] Furthermore, the maximum distance between the outer periphery of the radial plastic magnet and the central axis of the support frame is greater than or equal to the maximum distance between the outer periphery of the tangential ferrite and the central axis of the support frame.

[0029] Furthermore, the thickness of the damping rubber between the inner rotor core and the support frame is L5≥0.5mm, the thickness of the damping rubber at the outer end of the axial excitation source is L6≥1mm, and the overlap dimension of the inner rotor core and the support frame in the tangential direction is L7≥1mm.

[0030] Furthermore, the maximum diameter of the rotor's outer circle is D1, and the diameter of the mounting through hole is D3, with 0.25*D1≤D3≤0.5*D1.

[0031] Furthermore, the axial thickness of the axial excitation source is L8, and the total axial thickness of the rotor structure is L9, where 0.1*L9≤L8≤0.4*L9.

[0032] According to another aspect of the present invention, a method for forming the above-described rotor structure is provided, comprising:

[0033] Multiple rotor laminations are stacked together to form a radial plastic magnet;

[0034] Preparation of tangential ferrite;

[0035] Multiple radial plastic magnets are placed into the mold and positioned individually;

[0036] Multiple tangential ferrites are placed in the mold and positioned respectively;

[0037] Injection-molded permanent magnets into the mold, encapsulate radial plastic magnets and tangential ferrites to form an outer rotor structure, and then magnetize and orient the injection-molded permanent magnets.

[0038] Furthermore, the molding method also includes:

[0039] The inner rotor core is placed into the mold, and the relative positions of the inner rotor core and the outer rotor structure are defined.

[0040] Shock-absorbing adhesive is injected into the mold to encapsulate the outer rotor structure and the inner rotor core into one unit.

[0041] Furthermore, the steps of placing and positioning the radial plastic magnet in the mold include:

[0042] The radial plastic magnet is placed into the mold through the first positioning hole for positioning.

[0043] According to another aspect of the present invention, an electric motor is provided, comprising a stator structure and a rotor structure, wherein the rotor structure is the rotor structure described above, and the stator structure is sleeved on the outer periphery of the rotor structure.

[0044] According to the technical solution of this invention, the rotor structure includes: a support frame, which is integrally injection molded from injection-molded permanent magnets. The support frame includes tangential ferrite, radial excitation source, and axial excitation source. The tangential ferrite is used to form a tangential magnetic field. The radial excitation source is disposed on the radial inner side of the tangential ferrite and is used to form a radial magnetic field. The axial excitation source is disposed at both ends of the tangential ferrite and is used to form an axial magnetic field. An mounting groove is formed between adjacent tangential ferrites; radial plastic magnets, multiple radial plastic magnets are arranged at intervals along the circumference of the support frame, and each radial plastic magnet is correspondingly disposed in a mounting groove; tangential ferrite, which is used to form a tangential magnetic field, multiple tangential ferrites are correspondingly disposed in the second mounting groove. The support frame is integrally injection molded from injection-molded permanent magnets, integrating the tangential ferrite, radial excitation source, and axial excitation source together. Compared with traditional assembly methods, integral injection molding can reduce errors in the assembly process, improve the accuracy and reliability of the overall structure, simplify the production process, and reduce production costs. Since the tangential ferrite, radial excitation source, and axial excitation source are integrally injection molded with the radial plastic magnet before being magnetized, the types and number of permanent magnet rotor parts and the corresponding assembly processes can be reduced. There is no problem of mutual repulsion between different parts during assembly. The production process is relatively simple, the assembly difficulty is greatly reduced, and the reliability of motor assembly can be effectively improved. Attached Figure Description

[0045] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0046] Figure 1 A perspective structural diagram of the rotor structure according to an embodiment of the present invention is shown;

[0047] Figure 2 An exploded structural diagram of the rotor structure according to an embodiment of the present invention is shown;

[0048] Figure 3 A front view of the radial plastic magnet of the rotor structure according to an embodiment of the present invention is shown;

[0049] Figure 4 A schematic diagram of the overall structure of the radial plastic magnet of the rotor structure according to an embodiment of the present invention is shown;

[0050] Figure 5 A schematic diagram of the rotor structure before glue injection is shown in an embodiment of the present invention;

[0051] Figure 6 It shows Figure 5 A schematic diagram of the AA-direction cross-section structure;

[0052] Figure 7 It shows Figure 6 Schematic diagram of the BB-direction cross-section structure;

[0053] Figure 8 A schematic diagram of the external rotor structure according to an embodiment of the present invention is shown;

[0054] Figure 9 It shows Figure 8 Schematic diagram of the CC-direction cross-section structure;

[0055] Figure 10 It shows Figure 9 Schematic diagram of the DD-direction cross-section structure;

[0056] Figure 11 A schematic diagram of the internal rotor structure according to an embodiment of the present invention is shown;

[0057] Figure 12 A three-dimensional structural schematic diagram of the inner rotor structure according to an embodiment of the present invention is shown;

[0058] Figure 13 A cross-sectional structural diagram of the shock-absorbing adhesive according to an embodiment of the present invention is shown;

[0059] Figure 14 A schematic diagram of the rotor structure according to an embodiment of the present invention is shown;

[0060] Figure 15 It shows Figure 14 A schematic diagram of the EE cross-section structure; and

[0061] Figure 16 It shows Figure 15 A schematic diagram of the FF-directed cross-sectional structure.

[0062] The above figures include the following reference numerals:

[0063] 1. Support frame; 2. Tangential ferrite; 3. Radial excitation source; 4. Axial excitation source; 5. First mounting slot; 6. Radial plastic magnet; 7. Inner rotor core; 8. Damping rubber; 9. Mounting through hole; 10. First protrusion; 11. Second protrusion; 12. First groove; 13. Second groove; 14. Filling gap; 16. First positioning hole; 17. Injection hole; 18. Flow hole; 19. Central shaft hole; 20. Second positioning hole; 21. Second lateral protrusion; 22. Second mounting slot; 23. Injection molded connecting layer; 24. First lateral protrusion; 25. Axial connection; 26. Assembly hole. Detailed Implementation

[0064] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0065] See also Figures 1 to 16 As shown, according to an embodiment of the present invention, the rotor structure includes: a support frame 1, which is integrally injection molded from a permanent magnet; the support frame 1 includes a radial excitation source 3 and an axial excitation source 4; the axial excitation source 4 is located at both ends of the support frame 1 in the axial direction and is used to form an axial magnetic field; the radial excitation source 3 is disposed on the radial inner side of the axial excitation source 4 and is used to form a radial magnetic field; the radial excitation source 3 and the axial excitation source 4 form a first mounting groove 5; a radial plastic magnet 6, a plurality of radial plastic magnets 6 are arranged at intervals along the circumference of the support frame 1 in the first mounting groove 5, and a second mounting groove 22 is formed between adjacent radial plastic magnets 6; and a tangential ferrite 2, which is used to form a tangential magnetic field; a plurality of tangential ferrites 2 are disposed one-to-one in the second mounting groove 22.

[0066] The injection-molded permanent magnet structure serves as the rotor's excitation source and consists of two main parts. The radial part's magnetization direction is parallel to the rotor's radial direction, while the axial part's magnetization direction is parallel to the rotor's shaft direction. The tangential parts are evenly distributed circumferentially, with the radial parts located on the inner sides between adjacent tangential parts and the axial parts located at the upper and lower ends of the tangential parts. The excitation sources in the radial, tangential, and axial directions are injection-molded from the same permanent magnet material, typically using plastic-coated ferrite particles.

[0067] See also Figure 1 The diagram shows a perspective view of the rotor structure. The support frame 1 includes tangential ferrites 2, radial excitation sources 3, and axial excitation sources 4. The tangential ferrites 2 form the outer edge of the rotor, and a first mounting groove 5 is provided between adjacent tangential ferrites 2 to provide space for the installation of radial plastic magnets 6. The radial plastic magnets 6 are designed to correspond one-to-one with the first mounting grooves 5, thereby ensuring that each ferrite piece can be accurately embedded in its predetermined position. This structure not only simplifies the assembly process but also utilizes the synergistic effect of the tangential ferrites 2, radial excitation sources 3, and axial excitation sources 4 to form a stronger and more uniform magnetic field distribution, thereby improving the magnetic performance of the rotor.

[0068] In this embodiment, the support frame 1, radial excitation source 3, and axial excitation source 4 are integrally injection molded from permanent magnets. During the injection molding process, the tangential ferrite 2 and radial plastic magnet 6 are wrapped around each other, integrating the tangential ferrite 2, radial plastic magnet 6, radial excitation source 3, and axial excitation source 4 into a single rotor structure. Compared to traditional assembly methods, integral injection molding can reduce errors during assembly, improve the accuracy and reliability of the overall structure, simplify the production process, and reduce production costs. Since the tangential ferrite 2, radial excitation source 3, and axial excitation source 4 are magnetized after integral injection molding with the radial plastic magnet 6, the types and number of permanent magnet rotor parts and the corresponding assembly steps are reduced. There is no problem of mutual repulsion between different parts during assembly, the production process is simpler, the assembly difficulty is greatly reduced, and the reliability of motor assembly is effectively improved.

[0069] By setting tangential ferrite 2, radial excitation source 3 and axial excitation source 4, a three-dimensional magnetic field layout is realized on the rotor structure. The magnetic path of the excitation source can be realized as three parallel paths in three-dimensional space: radial, tangential and axial. This improves the performance of the motor, reduces the size of the motor, enhances the magnetic cohesion effect of the motor, and improves the utilization efficiency of magnetic force.

[0070] The first mounting groove 5 on the support frame 1 provides a mounting position for the radial plastic magnets 6. The radial plastic magnets 6 are arranged at intervals along the circumference of the support frame 1, and their precise fit with the first mounting groove 5 ensures the continuity and stability of the magnetic circuit. The axial excitation source 4 is located at both ends of the support frame 1 and is used to form the axial magnetic field. The radial excitation source 3 is set on the radial inner side of the axial excitation source 4. By setting the axial excitation source 4 at both ends of the support frame 1 and the radial excitation source 3 on the radial inner side of the axial excitation source 4, leakage flux can be effectively reduced, the utilization efficiency of the permanent magnets can be improved, and the mechanical strength of the rotor structure can be increased. Stress concentration during high-speed operation or when subjected to external impact can be reduced, structural damage can be avoided, and the reliability and life of the motor can be improved.

[0071] In one embodiment, there is an assembly gap between the tangential ferrite 2 and the radial plastic magnet 6, and the support frame 1 also includes an injection-molded connecting layer 23 integrally injection-molded with the radial excitation source 3 and the axial excitation source 4, the injection-molded connecting layer 23 filling the assembly gap.

[0072] Through the above-mentioned limitations, the assembly gap ensures that the tangential ferrite 2 maintains an appropriate distance from the radial plastic magnet 6 during assembly. This prevents collisions between the tangential ferrite 2 and the radial plastic magnet 6, which could damage the surface of the tangential ferrite 2, or friction with the radial plastic magnet 6 could generate high temperatures that could damage the magnetic circuit of the tangential ferrite 2. This protects the magnetic circuit of the tangential ferrite 2 from damage, maintaining the high performance and reliability of the motor. After the permanent magnet material is injection-molded to fill the assembly gap, forming the injection-molded connecting layer 23, the geometric accuracy of the rotor structure assembly is ensured, and the connection strength and stability between components are enhanced.

[0073] In one embodiment, the radial outer side of the radial plastic magnet 6 protrudes circumferentially to both sides to form a first lateral protrusion 24, which stops the radial outer side of the tangential ferrite 2.

[0074] Through the above-mentioned limitations, the first lateral protrusion 24 can effectively restrict the radial and tangential displacement of the tangential ferrite 2, ensuring that the tangential ferrite 2 can remain stable during motor operation, especially during high-speed rotation, and preventing the tangential ferrite 2 from shifting or even being thrown out and detached from the support frame 1 under the action of centrifugal force, thereby ensuring the continuity and strength of the magnetic field, and thus improving the magnetic performance and working stability of the motor.

[0075] In one embodiment, the radially shaped magnet 6 comprises strontium ferrite, barium ferrite, and nylon, which are formed by melting the above materials.

[0076] In this embodiment, strontium ferrite and barium ferrite are two common magnetic materials with excellent magnetic properties, including high remanence and coercivity. Compared to more expensive rare-earth permanent magnet materials, ferrite magnets offer a cost advantage while providing sufficient magnetic flux, making them suitable for various motor applications. Using strontium ferrite and barium ferrite as the main components of the radial plastic magnet 6 ensures good electromagnetic performance of the motor rotor while controlling costs. Nylon, as a polymer material, possesses excellent mechanical strength and processing properties. Adding nylon to the radial plastic magnet 6 improves the structural stability and impact resistance of the magnet.

[0077] In one embodiment, the radial plastic magnet 6 is radially magnetized, and the polarity of the radial plastic magnet 6 on the radially outer side is the same as the polarity of the tangential ferrite 2 and the axial excitation source 4 on the side facing the radial plastic magnet 6, while the polarities of two adjacent radial plastic magnets 6 in the circumferential direction are opposite.

[0078] In this embodiment, the polarity of the tangential ferrite 2 and the axial excitation source 4 formed on the same radial plastic magnet 6 is the same as the polarity of the radially magnetized radial plastic magnet 6 on its radially outer side. The polarities of two adjacent radial plastic magnets 6 along the circumferential direction are opposite. This magnetic pole arrangement can generate a more complex and efficient magnetic field distribution, significantly enhancing the magnetic flux path of the motor. Specifically, the excitation sources with the same polarity work synergistically on the same radial plastic magnet 6, superimposing with the magnetic field on the radial plastic magnet 6, enhancing the magnetic field strength in this region, thereby improving the electromagnetic torque and power density of the motor. The design of adjacent radial plastic magnets 6 with opposite polarities promotes the alternating flow of magnetic flux, optimizes the motor's magnetic circuit, reduces magnetic flux leakage and loss, and thus improves the motor's efficiency and operating performance.

[0079] In one embodiment, the tangential ferrite 2 is made of plastic magnetic ferrite particles.

[0080] In one embodiment, the bottom of the axial excitation source 4 is provided with an assembly hole 26.

[0081] In this embodiment, after the axial excitation source 4 is placed into the mold, it is supported by the assembly hole 26, maintaining a certain height between the axial excitation source 4 and the mold base plate. This allows the injection-molded permanent magnet to evenly wrap around the axial excitation source 4 on both sides along the axial direction. Simultaneously, the assembly hole 26 positions the axial excitation source 4, ensuring its stability during the injection molding process and preventing circumferential or radial movement under external forces, which could cause positional deviation and affect the performance and reliability of the finished rotor.

[0082] In one embodiment, the thickness of the injection-molded connecting layer 23 is 0.05 mm to 0.2 mm.

[0083] In this embodiment, an excessively thick injection-molded connecting layer 23 will occupy the accommodating space of the tangential ferrite 2, reducing the effective volume of the tangential ferrite 2, thereby affecting the overall performance of the rotor and motor.

[0084] In one embodiment, the support frame 1 further includes an axial connection portion 25, which is axially connected between the two axial excitation sources 4 and is located radially outside the tangential ferrite 2.

[0085] In this embodiment, the axial connection 25 enhances the structural stability of the entire rotor by connecting two axial excitation sources 4 along the axial direction. Especially when subjected to axial force or high-speed rotation, it can effectively reduce the displacement of the axial excitation sources and improve the rotor's vibration resistance and reliability. Placing the axial connection 25 on the radially outer side of the tangential ferrite 2 can form a more continuous and closed magnetic circuit. The axial magnetic field generated by the axial excitation source 4 can be smoothly transmitted to the tangential ferrite 2, and then cooperate with the magnetic field of the radial excitation source 3 to reduce magnetic flux leakage and improve magnetic circuit efficiency. The axial connection 25 is integrally injection molded with the support frame 1, which can reduce the number of independent parts, simplify assembly steps, reduce alignment errors during assembly, and improve production efficiency and assembly accuracy.

[0086] In one embodiment, the radially outer side of the axial connecting portion 25 protrudes circumferentially to both sides to form a second lateral protrusion 21, which stops the radially outer side of the first lateral protrusion 24.

[0087] In this embodiment, the second lateral protrusion 21 of the axial connection portion 25 effectively fixes the position of the radial plastic magnet 6 by means of the radially outer stop, thereby enhancing the structural stability of the rotor assembly and the integrity of the magnetic circuit, and thus improving the efficiency and reliability of the motor.

[0088] In one embodiment, the injection width L3 of the axial connecting part 25 on the outer circle is greater than the injection width L4 of the middle part, which can effectively fix and limit the radial plastic magnet 6 in the circumferential direction. The axial excitation source 4 can form an axial fixation of the radial plastic magnet 6. The axial connecting part 25 and the axial excitation source 4 cooperate to form a stable and reliable limit for the radial plastic magnet 6.

[0089] In this embodiment, the radial excitation source 3 and the axial excitation source 4 are injection molded from the same permanent magnet material. The tangential portion is evenly distributed circumferentially, the axial portion is distributed at the upper and lower ends of the tangential portion, and the radial portion is distributed between two adjacent tangential portions.

[0090] In one embodiment, the rotor structure further includes an inner rotor core 7 and damping rubber 8. The support frame 1 has a mounting through hole 9. A plurality of first protrusions 10 are spaced apart circumferentially on the inner wall of the mounting through hole 9. Second protrusions 11 are spaced apart circumferentially on the outer peripheral wall of the inner rotor core 7. A first groove 12 is formed between adjacent first protrusions 10, and a second groove 13 is formed between adjacent second protrusions 11. The first protrusions 10 are disposed in the second grooves 13 and form a filling gap 14 with the inner wall of the second grooves 13. The second protrusions 11 are disposed in the first grooves 12 and form a filling gap 14 with the inner wall of the first grooves 12. The damping rubber 8 is filled in the filling gap 14.

[0091] In this embodiment, the support frame 1 and the radial plastic magnet 6 are combined to form the outer rotor core, and the inner rotor core 7 is disposed in the mounting through hole 9 of the radial plastic magnet and connected and fixed by the damping adhesive 8. The rotor structure of this embodiment includes the support frame 1 formed by injection-molded permanent magnets, the radial plastic magnet 6, the inner rotor core 7, and the damping adhesive 8. Among them, the injection-molded permanent magnet mainly serves as the excitation source, providing a stable permanent magnet field for the rotor; the radial plastic magnet 6 mainly serves as the magnetic conductor, exporting the magnetic field generated by the injection-molded permanent magnet and coupling it with the stator magnetic field of the motor; the inner rotor core 7 mainly serves as the torque transmitter, outputting the motor torque to the application end through cooperation with the motor rotor shaft; the damping adhesive 8 mainly serves as the absorber of electromagnetic vibration waves and buffers vibration.

[0092] See also Figure 2 The diagram provides a perspective view of the rotor's internal structure, revealing the connection between the support frame 1 and the inner rotor core 7, as well as the distribution of the damping adhesive 8. The support frame 1 has mounting through holes 9, and its inner wall has multiple first protrusions 10 evenly distributed circumferentially. Correspondingly, second protrusions 11 are arranged on the outer peripheral wall of the inner rotor core 7. Each second protrusion 11 corresponds to a first groove 12, and each first protrusion 10 corresponds to a second groove 13. The first protrusions 10 are embedded in the second grooves 13, and the second protrusions 11 are embedded in the first grooves 12. This staggered interlocking structure not only enhances the mechanical connection between the support frame 1 and the inner rotor core 7 but also provides filling gaps 14, offering a channel for the injection of the damping adhesive 8. The damping adhesive 8 fills these gaps, forming an effective vibration isolation layer that absorbs stress generated by vibration during motor operation, reduces noise, and improves the smoothness of motor operation.

[0093] Radial plastic magnets 6 are evenly distributed around the rotor along the circumference. The number of radial plastic magnets 6 is Z1 = 2 * P, where P is the number of pole pairs of the rotor. The injection-molded permanent magnets wrap and fix the radial plastic magnets 6 through injection molding to form the outer rotor structure of the rotor structure, and leave a mounting through hole 9 on the inner side of the outer rotor structure. The inner rotor core 7 is placed in the mounting through hole 9 of the outer rotor structure. The damping adhesive 8 is injected into the gap between the outer rotor structure and the inner rotor core 7 and wraps the two in the axial direction to increase the bonding strength.

[0094] The damping adhesive 8 filled in the gaps forms a three-dimensional interlocking and limiting structure, which not only enhances the connection between the inner rotor core 7 and the support frame 1 in the axial, radial, and tangential directions, but also effectively reduces stress concentration when transmitting torque or subjected to external impact, preventing damage to the damping structure and improving the overall strength and reliability of the structure. The fit between the first protrusion 10 on the inner wall of the mounting through hole 9 and the second protrusion 11 on the inner rotor core 7 not only helps to position the inner rotor core 7, but also ensures the uniform distribution of the damping adhesive 8 during injection molding, thereby achieving the best damping effect.

[0095] In one embodiment, a first positioning hole 16 is provided axially through the radial plastic magnet 6. The first positioning hole 16 is a non-circular hole and is filled with damping adhesive 8. By providing the non-circular first positioning hole 16 to install and position the radial plastic magnet 6, the positioning of the radial plastic magnet 6 during the injection molding of the support frame 1 can be effectively prevented from rotating during the injection molding of the support frame 1, ensuring the structural stability of the radial plastic magnet 6 during the injection molding of the support frame 1 and ensuring the injection molding quality of the support frame 1.

[0096] In one embodiment, the first positioning hole 16 is a polygonal hole, such as a square hole or a pentagonal hole.

[0097] After the positioning injection molding of the support frame 1 is completed, the damping adhesive 8 can be filled into the first positioning hole 16, thereby using the damping adhesive 8 to further enhance the bonding strength between the radial plastic magnet 6 and the support frame 1, and at the same time, it can also form an effective damping effect.

[0098] In one embodiment, the inner rotor core 7 has an axially oriented injection hole 17, which is filled with damping adhesive 8.

[0099] By creating injection holes 17 on the inner rotor core 7 and filling the holes with damping adhesive 8, the motor's vibration damping performance and overall strength are effectively improved. The design of the injection holes 17 not only provides a path for the filling of the damping adhesive 8, ensuring its uniform distribution within the rotor structure, but also further strengthens the bond between the inner rotor core 7 and the outer rotor structure, preventing adhesive detachment during high-speed operation or impact, thus enhancing the overall stability of the rotor. Furthermore, the uniformly distributed damping adhesive 8 can more effectively absorb vibrations and noise generated during motor operation, achieving low-vibration, low-noise operation of the motor.

[0100] In one embodiment, both the first positioning hole 16 and the injection hole 17 are filled with damping adhesive 8. The outer end face of the axial excitation source 4 is provided with damping adhesive 8. A flow hole 18 is provided on the axial excitation source 4 in a circumferential manner corresponding to the first positioning hole 16. The damping adhesive 8 flows into the first positioning hole 16 through the flow hole 18. The first positioning hole 16, the injection hole 17, the outer end face of the axial excitation source 4 and the damping adhesive 8 in the flow hole 18 are an integral structure, and the damping adhesive 8 forms a cage-like structure.

[0101] In this embodiment, the damping adhesive 8 not only fills the first positioning hole 16 and the injection hole 17, but also forms a covering layer on the outer end face of the axial excitation source 4, and connects these filling positions through the flow hole 18 to form an integrated cage structure. The damping adhesive 8 of the cage structure forms a continuous adhesive layer in the radial, tangential and axial directions, effectively connecting the inner rotor core 7, the radial plastic magnet 6 and the support frame 1 tightly, improving the bonding strength between these key components, and ensuring the structural stability of the rotor when running at high speed or subjected to external impact. The integrated damping adhesive 8 can be more evenly distributed in the rotor structure, not only absorbing the vibration energy caused by electromagnetic excitation force, but also effectively buffering the radial, tangential and axial vibration force waves generated between the outer rotor structure and the inner rotor core 7 during motor operation, reducing the operating noise of the motor, improving the overall damping effect, and ensuring the smooth operation of the motor.

[0102] By providing a flow hole 18 on the axial excitation source 4, the damping adhesive 8 can flow into the first positioning hole 16 through the flow hole during injection molding, ensuring accurate filling of the damping adhesive at critical positions, simplifying the assembly process, reducing positional deviations caused by multi-step assembly, and improving the consistency and reliability of motor performance. The cage-like structure of the damping adhesive 8 is formed in one step through injection molding, reducing material costs and assembly time, while avoiding additional connecting parts and lowering production costs. The integrated adhesive layer formed on the first positioning hole 16, the injection hole 17, and the outer end face of the axial excitation source 4 can better support and fix the magnetic material, improving material utilization.

[0103] In one embodiment, a recessed groove is provided on the radially inner part of the axial end face of the axial excitation source 4, and the damping adhesive 8 is filled in the recessed groove. Without affecting the axial height and axial magnetic field strength of the axial excitation source 4, it is more convenient to form an integrated adhesive injection structure with the inner rotor core 7 located on the radially inner circumference of the axial excitation source 4, and it is more convenient to realize the connection and fixation between the inner rotor core 7 and the outer rotor structure.

[0104] In one embodiment, each side of the first protrusion 10 is parallel to the corresponding side of the second groove 13, and each side of the second protrusion 11 is parallel to the corresponding side of the first groove 12.

[0105] The parallel side engagement structure ensures precise alignment and a secure connection between the inner rotor core 7 and the support frame 1. This design effectively reduces relative slippage during torque transmission, improving the rotor's tangential positioning accuracy. Furthermore, the parallel side contact evenly distributes contact pressure, avoiding stress concentration and thus reducing material wear and potential structural failure risks, increasing the rotor's reliability and lifespan. During motor operation, this engagement limiting structure effectively suppresses vibration and noise. By limiting radial and tangential displacement, it enhances the motor's smooth operation and quietness, further improving overall motor performance and user experience.

[0106] In one embodiment, the damping adhesive 8 filled in the filling gap 14 is continuous in the circumferential direction, isolating and connecting the support frame 1 and the inner rotor core 7.

[0107] The damping rubber 8, filled in the circumferentially continuous filling gap 14, effectively isolates and connects the support frame 1 and the inner rotor core 7, enhancing the structural stability and damping effect of the rotor, while ensuring synchronous rotation between the two components, thus improving the smoothness and efficiency of motor operation.

[0108] In one embodiment, the inner rotor core 7 has a central shaft hole 19, and a second positioning hole 20 is provided on the inner wall of the central shaft hole 19 to position the inner rotor core 7 and the support frame 1 in a circumferential relative position.

[0109] The second positioning hole 20, located on the inner wall of the central shaft hole 19 of the inner rotor core 7, ensures precise circumferential positioning between the inner rotor core and the support frame 1, and ensures that the inner rotor core is centered in the mounting through hole 9 of the outer rotor structure. This effectively improves the assembly accuracy and operational stability of the rotor assembly, and makes the distribution of the damping rubber 8 in the filling gap 14 more uniform, thereby improving the overall performance and efficiency of the motor.

[0110] In one embodiment, the maximum distance D1 between the outer periphery of the radial plastic magnet 6 and the central axis of the support frame 1 is greater than or equal to the maximum distance D2 between the outer periphery of the injection-molded permanent magnet and the central axis of the support frame 1.

[0111] In this embodiment, the maximum distance D1 between the outer periphery of the radial plastic magnet 6 and the central axis of the support frame 1 forms the maximum outer diameter of the outer rotor structure, and the maximum distance D2 between the outer periphery of the injection-molded permanent magnet and the central axis of the support frame 1 forms the maximum outer diameter of the support frame 1. By limiting D2≤D1, the problem of the outer rotor structure rubbing against the stator due to burrs caused by poor injection molding can be effectively avoided, thereby improving the operational reliability of the rotor structure.

[0112] In one embodiment, the thickness L5 of the damping rubber 8 between the inner rotor core 7 and the support frame 1 is ≥0.5mm, the thickness L6 of the damping rubber 8 at the outer end of the axial excitation source 4 is ≥1mm, and the overlap dimension L7 between the inner rotor core 7 and the support frame 1 in the tangential direction is ≥1mm.

[0113] By ensuring that the thickness L5 of the damping rubber 8 between the inner rotor core 7 and the support frame 1 is ≥0.5mm, the thickness L6 of the damping rubber at the outer end of the axial excitation source 4 is ≥1mm, and the overlap dimension L7 of the two along the tangential direction is ≥1mm, the damping effect and the connection strength of the damping rubber 8 are effectively guaranteed, the damping effect and structural stability of the rotor structure are enhanced, and sufficient torque transmission efficiency is guaranteed at the same time.

[0114] In one embodiment, the maximum diameter of the rotor's outer circle is D1, and the diameter of the mounting through hole 9 is D3, where 0.25*D1≤D3≤0.5*D1.

[0115] By controlling the diameter D3 of the mounting through hole 9 to be between 25% and 50% of the maximum outer diameter D1 of the rotor, the magnetic circuit design and mechanical strength of the motor rotor are optimized, ensuring that the motor has good structural stability and resistance to external impact while achieving efficient energy conversion, thereby improving the overall performance and reliability of the motor.

[0116] In one embodiment, the axial thickness of the axial excitation source 4 is L8, and the total axial thickness of the rotor structure is L9, where 0.1*L9≤L8≤0.4*L9.

[0117] The axial thickness L8 of the axial excitation source 4 is set between 10% and 40% of the total axial thickness L9 of the rotor structure, which effectively balances the axial magnetic flux density of the motor with the overall structural compactness, improves the electromagnetic performance and operational stability of the motor, and reduces material costs, thus achieving a dual optimization of motor efficiency and economy.

[0118] According to an embodiment of the present invention, the above-mentioned method for forming the rotor structure includes: melting to form a radial plastic magnet; preparing a tangential ferrite; placing a plurality of radial plastic magnets into a mold and positioning them respectively; placing a plurality of tangential ferrites into a mold and positioning them respectively; injecting a molded permanent magnet into the mold, encapsulating the radial plastic magnet and the tangential ferrite together to form an outer rotor structure, and performing magnetization orientation of the molded permanent magnet.

[0119] The above-described molding method utilizes an integrated injection molding process. First, multiple radial plastic magnets 6 are formed by melting. Then, tangential ferrite particles are formed into tangential ferrites 2 through methods such as sintering. The radial plastic magnets 6 are then placed into a mold for fixation. A support rod is inserted into the mold, with its diameter matching that of the mounting hole 26. The support rod's position corresponds to the mounting hole 26, and its extension into the mold is equal to the height of the axial excitation source 4. This allows the support rod to position and support the tangential ferrite 2 in the vertical direction. The support rod, in conjunction with the radial plastic magnets 6, positions the tangential ferrite 2 within the mold. Subsequently, injection-molded permanent magnets are injected into the mold, tightly bonding the radial plastic magnets 6 and the tangential ferrite 2 to form a stable outer rotor structure. After injection molding, the support rod is removed, leaving the mounting hole 26 on the axial excitation source. In this molding method, the precise placement and positioning of the radial plastic magnets 6 within the mold ensures accurate magnetic pole positioning, laying the foundation for subsequent magnetic field optimization. By injecting permanent magnets into the mold and wrapping them around the radial plastic magnet 6 and the tangential ferrite 2, not only is a tight connection of materials achieved, eliminating gaps and magnetic circuit discontinuities that may occur in traditional assembly, but the magnetization orientation of the permanent magnets is also completed during the injection molding process. This avoids the increased assembly difficulty caused by like pole repulsion, reduces assembly difficulty, improves assembly efficiency, and effectively ensures the consistency and strength of the magnetic field, further enhancing the performance of the motor. The integrated injection molding process also reduces assembly steps, lowers production costs, and improves the reliability and durability of the rotor structure. The injection molding material effectively fills the tiny gaps between components, thus enhancing overall mechanical strength and reducing vibration and noise during operation.

[0120] In one embodiment, the molding method further includes: placing the inner rotor core into a mold and defining the relative position of the inner rotor core and the outer rotor structure; injecting damping adhesive into the mold to wrap the outer rotor structure and the inner rotor core together.

[0121] The method of precisely placing the inner rotor core 7 and defining its relative position with the outer rotor structure, then injecting damping adhesive 8 into the mold to wrap the two together, effectively enhances the structural stability and damping performance of the rotor, while simplifying the assembly process and ensuring the smoothness and quietness of the motor operation.

[0122] In one embodiment, the step of placing and positioning the radial plastic magnet in the mold includes: positioning the radial plastic magnet in the mold through a first positioning hole.

[0123] The step of precisely placing and fixing the radial plastic magnet 6 in the mold through the first positioning hole 16 ensures accurate alignment of the magnetic poles and geometric consistency of the rotor structure, effectively guaranteeing the structural accuracy and molding quality of the injection molding support frame 1 for the injection-molded permanent magnet, and improving injection molding efficiency.

[0124] According to an embodiment of the present invention, the motor includes a stator structure and a rotor structure, wherein the rotor structure is the rotor structure described above, and the stator structure is sleeved on the outer periphery of the rotor structure.

[0125] 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 exemplary embodiments according to this application. 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.

[0126] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in sequences other than those illustrated or described herein.

[0127] 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. A rotor structure, characterized by, include: Support frame (1), the support frame (1) is integrally injection molded from injection molded permanent magnets, the support frame (1) includes a radial excitation source (3) and an axial excitation source (4), the axial excitation source (4) is located at both ends of the support frame (1) and is used to form an axial magnetic field, the radial excitation source (3) is arranged on the radial inner side of the axial excitation source (4) and is used to form a radial magnetic field, the radial excitation source (3) and the axial excitation source (4) form a first mounting groove (5); radial plastic magnets (6), a plurality of radial plastic magnets (6) are arranged at intervals along the circumference of the support frame (1) in the first mounting groove (5), and a second mounting groove (22) is formed between adjacent radial plastic magnets (6); Tangential ferrite (2) is used to form a tangential magnetic field. A plurality of tangential ferrites (2) are arranged one-to-one in the second mounting groove (22).

2. The rotor structure of claim 1, wherein There is an assembly gap between the tangential ferrite (2) and the radial plastic magnet (6), and the support frame (1) also includes an injection-molded connecting layer (23) integrally injection-molded with the radial excitation source (3) and the axial excitation source (4), and the injection-molded connecting layer (23) fills the assembly gap.

3. The rotor structure of claim 1, wherein The radial outer side of the radial plastic magnet (6) protrudes circumferentially to both sides to form a first lateral protrusion (24), which stops the radial outer side of the tangential ferrite (2).

4. The rotor structure according to claim 1, characterized in that, The radial plastic magnet (6) is made by melting.

5. The rotor structure according to claim 1, characterized in that, The radial plastic magnet (6) includes strontium ferrite, barium ferrite and nylon.

6. The rotor structure according to claim 1, characterized in that, The radial plastic magnet (6) is radially magnetized, and the radial outer polarity of the radial plastic magnet (6) is the same as the magnetism of the circumferentially adjacent excitation source on the side facing the radial plastic magnet (6).

7. The rotor structure according to claim 1, characterized in that, The tangential ferrite (2) is made of plastic magnetic ferrite particles.

8. The rotor structure according to claim 2, characterized in that, The thickness of the injection-molded connecting layer (23) is 0.05mm to 0.2mm.

9. The rotor structure according to claim 1, characterized in that, The support frame (1) also includes an axial connection part (25), which is axially connected between the two axial excitation sources (4) and is located on the radially outer side of the tangential ferrite (2).

10. The rotor structure according to claim 9, characterized in that, The radial outer side of the axial connecting part (25) protrudes to both sides in the circumferential direction to form a second lateral protrusion (21), and the radial outer side of the radial plastic magnet (6) protrudes to both sides in the circumferential direction to form a first lateral protrusion (24). The second lateral protrusion (21) stops on the radial outer side of the first lateral protrusion (24).

11. The rotor structure according to claim 1, characterized in that, The rotor structure also includes an inner rotor core (7) and damping rubber (8). The support frame (1) has a mounting through hole (9). A plurality of first protrusions (10) are arranged circumferentially on the inner wall of the mounting through hole (9). A second protrusion (11) is arranged circumferentially on the outer wall of the inner rotor core (7). A first groove (12) is formed between adjacent first protrusions (10). A second groove (13) is formed between adjacent second protrusions (11). The first protrusions (10) are disposed in the second groove (13) and form a filling gap (14) with the inner wall of the second groove (13). The second protrusions (11) are disposed in the first groove (12) and form the filling gap (14) with the inner wall of the first groove (12). The damping rubber (8) fills the filling gap (14).

12. The rotor structure according to claim 11, characterized in that, The radial plastic magnet (6) is provided with a first positioning hole (16) through it along the axial direction. The first positioning hole (16) is a non-circular hole and is filled with the damping adhesive (8). And / or, the inner rotor core (7) is provided with an injection hole (17) along the axial direction and is filled with the damping adhesive (8).

13. The rotor structure according to claim 12, characterized in that, The first positioning hole (16) and the injection hole (17) are both filled with the damping adhesive (8). The damping adhesive (8) is provided on the outer end face of the axial excitation source (4). A flow hole (18) is provided on the axial excitation source (4) in a circumferential direction corresponding to the first positioning hole (16). The damping adhesive (8) flows into the first positioning hole (16) through the flow hole (18). The first positioning hole (16), the injection hole (17), the outer end face of the axial excitation source (4) and the damping adhesive (8) in the flow hole (18) are an integral structure. The damping adhesive (8) forms a cage-like structure.

14. The rotor structure according to claim 11, characterized in that, The inner rotor core (7) has a central shaft hole (19), and a second positioning hole (20) is provided on the inner wall of the central shaft hole (19) to position the inner rotor core (7) and the support frame (1) in a circumferential relative position.

15. The rotor structure according to any one of claims 1 to 14, characterized in that, The maximum distance between the outer periphery of the radial plastic magnet (6) and the central axis of the support frame (1) is greater than or equal to the maximum distance between the outer periphery of the tangential ferrite (2) and the central axis of the support frame (1).

16. The rotor structure according to any one of claims 11 to 14, characterized in that, The thickness of the damping rubber (8) between the inner rotor core (7) and the support frame (1) is L5≥0.5mm, the thickness of the damping rubber (8) at the outer end of the axial excitation source (4) is L6≥1mm, and the overlap dimension of the inner rotor core (7) and the support frame (1) in the tangential direction is L7≥1mm.

17. A method for forming a rotor structure as described in any one of claims 1 to 16, characterized in that, include: Melting to form a radial plastic magnet; Preparation of tangential ferrite; Multiple radial plastic magnets are placed into the mold and positioned individually; Multiple tangential ferrites are placed in the mold and positioned respectively; Injection-molded permanent magnets into the mold, encapsulate radial plastic magnets and tangential ferrites to form an outer rotor structure, and then magnetize and orient the injection-molded permanent magnets.

18. The molding method according to claim 17, characterized in that, Molding methods also include: The inner rotor core is placed into the mold, and the relative positions of the inner rotor core and the outer rotor structure are defined. Shock-absorbing adhesive is injected into the mold to encapsulate the outer rotor structure and the inner rotor core into one unit.

19. The molding method according to claim 17, characterized in that, The steps for placing and positioning the radial plastic magnet in the mold include: The radial plastic magnet is placed into the mold through the first positioning hole for positioning.

20. An electric motor, comprising a stator structure and a rotor structure, characterized in that, The rotor structure is the rotor structure according to any one of claims 1 to 16, and the stator structure is sleeved on the outer periphery of the rotor structure.

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