Stator support and method of designing the same

Abstract

The application relates to a stator support and a design method thereof, which comprises a support body, a stator core is sleeved on the support body, the support body comprises a cylindrical base and a plurality of main spokes, the plurality of main spokes are uniformly distributed along the circumference of the cylindrical base, one end of the main spoke is connected with the outer circumferential surface of the cylindrical base, the other end of the main spoke is in contact with the inner circumferential surface of the stator core, a vice spoke is arranged between any two adjacent main spokes, the two ends of the vice spoke are connected to the opposite sides of the two adjacent main spokes, and the axial thickness of the main spoke is greater than that of the vice spoke. In the application, the weight of the support body is greatly reduced, light weight is realized, the axial thickness of the main spoke is greater than that of the vice spoke, a stepped stiffness topology is formed, high-frequency electromagnetic resonance is inhibited through passive stiffness design, intrinsic vibration reduction and light weight are considered, and the light weight and NVH optimization of the motor are realized.

Description

Technical Field

[0001] This invention relates to a stator support and its design method, belonging to the field of hub motor technology. Background Technology

[0002] During operation, the stator support of an external rotor hub motor directly bears the radial high-frequency electromagnetic excitation force generated by the air gap magnetic field. Existing hub motor stator supports mostly adopt a homogeneous solid disc structure or a regularly distributed open structure. This structure has a uniform circumferential stiffness distribution, and its low-order (e.g., 4th order) radial breathing mode is highly susceptible to coupling with the high-frequency components of the motor's electromagnetic force waves, thus inducing resonance. Resonance not only leads to fatigue damage to the stator assembly but also transmits significant structural noise to the entire vehicle. Furthermore, the solid disc structure increases the unsprung mass of the motor, which is detrimental to the lightweight design of the entire vehicle.

[0003] Currently, most patents and research on in-wheel motor vibration issues focus on the vehicle suspension system level (e.g., introducing dynamic shock absorbers or active suspension control algorithms), aiming to solve the low-frequency road impact problem caused by excessive unsprung mass of the motor. However, such external suspension systems are complex in structure, expensive, and cannot solve the stator resonance problem caused by the high-frequency radial electromagnetic excitation force generated by the air gap magnetic field inside the motor. Especially for two-wheeled electric vehicles with limited installation space, relying solely on external suspension for vibration reduction makes it difficult to achieve both lightweighting and high-frequency acoustic noise reduction. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a stator support that combines vibration reduction and lightweight design, along with its design method.

[0005] To achieve the objective, the technical solution adopted by this invention is: A stator support includes a support body on which a stator core is fitted. The support body includes a cylindrical base and multiple main spokes. The main spokes are evenly distributed around the circumference of the cylindrical base. One end of each main spoke is connected to the outer circumferential surface of the cylindrical base, and the other end of each main spoke is in contact with the inner circumferential surface of the stator core. A secondary spoke is provided between any two adjacent main spokes, and the two ends of the secondary spoke are respectively connected to the opposite sides of the two adjacent main spokes. The axial thickness of the main spoke is greater than the axial thickness of the secondary spoke.

[0006] As a further optimization of the above technical solution: the secondary spokes are arc-shaped.

[0007] As a further optimization of the above technical solution: the center of the secondary spoke is bent towards the center of the main body of the support, so that the secondary spoke is arc-shaped.

[0008] As a further optimization of the above technical solution: multiple secondary spokes are provided between each of the two adjacent main spokes, and the multiple secondary spokes between the two adjacent main spokes are arranged in an increasing manner in terms of curvature from the outside to the inside.

[0009] As a further optimization of the above technical solution: multiple secondary spokes between two adjacent main spokes are arranged in a decreasing manner in terms of bending radius from the outside to the inside.

[0010] As a further optimization of the above technical solution: multiple secondary spokes between two adjacent main spokes are arranged in a decreasing radial width from the outside to the inside.

[0011] As a further optimization of the above technical solution: transition rounded corners are provided between the main spokes and the stator core, as well as at the connection between the main spokes and the auxiliary spokes.

[0012] As a further optimization of the above technical solution: the radius of the transition fillet is 0.5mm to 2.0mm.

[0013] As a further optimization of the above technical solution: the circumferential width of the main spoke gradually decreases from the outside to the inside.

[0014] As a further optimization of the above technical solution: the ratio of the axial thickness of the main spoke to the axial thickness of the secondary spoke is 1.2:1 to 2.0:1.

[0015] As a further optimization of the above technical solution: the number of main spokes is 5 to 12, and the number of secondary spokes between two adjacent main spokes is 2 to 6.

[0016] As a further optimization of the above technical solution: the cylindrical base has an inner hole at its center, and the bracket body is fitted onto the central shaft through the inner hole. Two bushings are also fitted onto the central shaft, and the two bushings are located on both sides of the bracket body. The central shaft has a cylindrical protrusion, and the two end faces of the protrusion are positioning step surfaces. The bracket body is fitted onto the protrusion, and the sides of the two bushings are in contact with the two positioning step surfaces respectively.

[0017] As a further optimization of the above technical solution: the main body of the bracket is integrally formed, the outer end face of the main spoke and the stator core are interference fit, and the main body of the bracket is located inside the hub motor.

[0018] A design method for a stator support as described in the above technical solution includes the following steps: obtaining the target electromagnetic excitation frequency range of the hub motor; establishing a three-dimensional model of the support body, using the axial thickness of the main spokes, the axial thickness of the secondary spokes, the transition fillet radius, and the number of main spokes as design variables; adjusting the values ​​of the design variables to generate the final structural dimensions of the support body, with the goal of achieving spatial mode decoupling of the support body within the target electromagnetic excitation frequency range and ensuring that the dynamic alternating stress and the maximum local equivalent stress under static load within the target frequency band are both less than a preset material safety threshold.

[0019] As a further optimization of the above technical solution, the step of "decoupling the spatial mode shape of the support body within the target electromagnetic excitation frequency range" also includes modal analysis and harmonic response analysis of the support body to verify whether the step thickness ratio of the main spokes and the secondary spokes meets the preset mode shape decoupling conditions.

[0020] As a further optimization of the above technical solution, the design variables also include the number of sub-spokes, the radial position of each sub-spoke, and the bending radius of each sub-spoke. The adjustment steps are optimized and solved by finite element parametric scanning or multi-objective genetic algorithm.

[0021] Compared with existing technologies, the main body of the bracket in this invention is significantly lighter, achieving weight reduction. Simultaneously, the axial thickness of the main spokes is greater than that of the secondary spokes, forming a stepped variable stiffness topology. This breaks through the frequency avoidance limitations of traditional structures. Starting from the structural topology of the motor stator bracket itself, high-frequency electromagnetic resonance is suppressed through passive variable stiffness design, achieving a balance between intrinsic vibration reduction and weight reduction. This solves the problems of existing solid brackets easily resonating with electromagnetic excitation forces and having excessive mass, effectively eliminating the risk of fatigue fracture and motor rotor failure, and achieving motor weight reduction and NVH optimization. The secondary spokes adopt an arc shape bending towards the center of the bracket body, maintaining stiffness while avoiding frequency and reducing vibration. Easy to process; the transition fillets smooth out the abrupt change in cross-sectional dimensions, which can reduce the local peak stress of the support body when subjected to alternating loads and ultimate torques, and improve the fatigue life of the topology; in the integrated molding process, the transition fillets can improve the flowability of the filling, suppress manufacturing defects such as root shrinkage cavities or cold shut cracks, and ensure the overall mechanical reliability of the support; the circumferential width of the main spokes gradually decreases from the outside to the inside, which plays a role in stiffness compensation, ensures the structural load-bearing capacity, and blocks the spatial coupling path between electromagnetic excitation force waves and the inherent modes of the support, thereby suppressing the resonance effect. At the same time, in conjunction with the axial thickness difference between the main spokes and the sub-spokes, they jointly promote the shift of the low-order natural frequency to the target frequency band, and achieve frequency misalignment and vibration avoidance. Attached Figure Description

[0022] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0023] Figure 2 This is an exploded structural diagram of the present invention.

[0024] Figure 3 This is a schematic diagram of the structure of the support body 1 in this invention.

[0025] Figure 4 This is a comparison diagram of the four modal vibration modes of the present invention.

[0026] Figure 5 is an equivalent stress distribution diagram of the present invention under ultimate load.

[0027] Figure 6 is a diagram showing the axial deformation distribution of the present invention under ultimate load.

[0028] Figure 7 is the acceleration frequency response curve of the present invention under harmonic response analysis.

[0029] Figure 8 is the equivalent elastic strain distribution diagram of the present invention under harmonic response analysis. Detailed Implementation

[0030] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. For example... Figure 1-8 As shown, a stator support and its design method are disclosed, including a support body 1, on which a stator core 4 is fitted to form a motor stator. The support body 1 includes a cylindrical base 11 and multiple main spokes 12, which are evenly distributed circumferentially along the cylindrical base 11. One end of each main spoke 12 is connected to the outer circumferential surface of the cylindrical base 11, and the other end is in contact with the inner circumferential surface of the stator core 4. A secondary spoke 13 is provided between any two adjacent main spokes 12, with both ends of the secondary spoke 13 connected to the opposite sides of the two adjacent main spokes 12. The axial thickness of the main spokes 12 is greater than the axial thickness of the secondary spokes 13, forming a stepped variable stiffness topology. Compared to a traditional solid structure with uniform thickness, the support body 1 significantly reduces weight, achieving lightweight design, while simultaneously lowering its lower-order natural frequencies. Under high-frequency electromagnetic excitation conditions, the stepped variable stiffness topology of the main spokes 12 and secondary spokes 13 within the support body 1 creates a mechanical impedance mismatch region. Under load, the thinner secondary spokes 13 preferentially undergo local elastic deformation, converting the kinetic energy excited by resonance into elastic strain energy for dissipation; the thicker main spokes 12 provide global torsional and radial support stiffness; effectively blocking the spatial coupling effect between electromagnetic excitation force waves and the inherent modes of the support, fundamentally suppressing the dynamic resonance response of the structure. This invention breaks through the frequency avoidance limitations of traditional structures, starting from the structural topology of the motor stator support itself, and suppresses high-frequency electromagnetic resonance through passive variable stiffness design, achieving a balance between intrinsic vibration reduction and lightweighting. It solves the problems of existing solid supports being prone to resonance with electromagnetic excitation forces and excessive mass, effectively eliminating the risk of fatigue fracture and motor rotor failure, and achieving motor lightweighting and NVH optimization.

[0031] In the above technical solution, the ratio of the axial thickness of the main spoke 12 to the axial thickness of the secondary spoke 13 is 1.2:1 to 2.0:1, that is, the axial thickness of the main spoke 12 is between 1.2 and 2.0 times the axial thickness of the secondary spoke 13. In this embodiment, the stator core stack height is 70mm; the axial thickness of the main spoke 12 is 30mm, which is used to provide the torsional and radial support stiffness of the foundation; the axial thickness of the secondary spoke is 20mm, and the ratio of the axial thickness of the main spoke to the secondary spoke is 1.5:1.

[0032] In the above technical solution, transition fillets 14 are provided at the connection between the main spokes 12 and the stator core 4, and at the connection between the main spokes 12 and the auxiliary spokes 13. The radius of the transition fillets 14 is 0.5mm to 2.0mm. The function of the transition fillets 14 is as follows: On the one hand, the transition fillets 14 smooth out the abrupt change in cross-sectional dimensions, which can reduce the local peak stress of the support body 1 when subjected to alternating loads and ultimate torques, and improve the fatigue life of the topology; on the other hand, in the integrated molding process, the transition fillets 14 can improve the filling flow, suppress manufacturing defects such as root shrinkage cavities or cold shut cracks, and ensure the overall mechanical reliability of the support.

[0033] In the above technical solution, the secondary spoke 13 is arc-shaped. More specifically, the center of the secondary spoke 13 bends towards the center of the support body 1, making the secondary spoke 13 arc-shaped. While achieving variable stiffness and stress smoothness, the secondary spoke 13 can also adopt other shapes, such as S-shaped or wavy; however, straight secondary spokes without curvature will be significantly less effective due to stress concentration and lack of gradual deformation capability. In this invention, the secondary spoke 13 adopts an arc-shaped shape bending towards the center of the support body 1, which maintains stiffness while avoiding frequency and reducing vibration, making it the optimal choice for comprehensive mechanical performance and also easy to process.

[0034] In the above technical solution: a plurality of auxiliary spokes 13 are disposed between every two adjacent main spokes 12, the plurality of auxiliary spokes 13 between two adjacent main spokes 12 are arranged in an increasing manner in bending radian from outside to inside, the plurality of auxiliary spokes 13 between two adjacent main spokes 12 are arranged in a decreasing manner in bending radius from outside to inside, and the plurality of auxiliary spokes 13 between two adjacent main spokes 12 are arranged in a decreasing manner in radial width from outside to inside, so that the support main body 1 forms a variable stiffness distribution in the radial direction, and the support main body 1 is approximately in a spider web shape. The number of the auxiliary spokes 13 between every two adjacent main spokes 12 is 2 to 6. In this embodiment, three auxiliary spokes 13 are disposed between every two adjacent main spokes 12, which are a first auxiliary spoke, a second auxiliary spoke and a third auxiliary spoke distributed sequentially from inside to outside, the radial distances of the positions of the first auxiliary spoke, the second auxiliary spoke and the third auxiliary spoke from the outer edge of the cylindrical base 11 (referred to as radial positions for short) are L1, L2 and L3 respectively, where L1<L2<L3, more specifically, L1 is 13mm, L2 is 46mm, and L3 is 76mm; the bending radii of the first auxiliary spoke, the second auxiliary spoke and the third auxiliary spoke are R1, R2 and R3 respectively, where R1<R2<R3, more specifically, R1 is 16mm, R2 is 28mm, and R3 is 62mm; the radial widths of the first auxiliary spoke, the second auxiliary spoke and the third auxiliary spoke are H1, H2 and H3 respectively, where H1<H2<H3, more specifically, H1 is 4mm, H2 is 6mm, and H3 is 8mm. The specific dimension arrangement with unequal spacing and variable curvature, in cooperation with the axial thickness difference between the main spokes 12 and the auxiliary spokes 13, makes the bending section coefficients of the support main body 1 at different radius positions different, which further breaks the uniform force transmission path of the conventional disc.

[0035] In the above technical solution: the circumferential width of the main spokes 12 gradually decreases from outside to inside, that is, the width of the end of the main spoke 12 close to the stator core 4 is greater than the width of the end of the main spoke 12 close to the cylindrical base 11. The above structure brings the following effects: 1. Stiffness compensation: the present invention achieves a weight reduction of about 47% by removing a large amount of material. In order to avoid excessive reduction of stiffness, the width of the outer end of the main spoke 12 is increased in the high-stress force transmission region close to the stator core 4, which effectively compensates for the radial and torsional stiffness loss caused by grooving for weight reduction, and ensures the structural load-bearing capacity; 2. Modal decoupling and frequency shifting: the non-uniform width design of the main spokes 12 makes the bending inertia of each section along the radial direction non-linearly distributed, which breaks the condition for synchronous forced vibration of the spokes with conventional uniform sections, blocks the spatial coupling path between the electromagnetic excitation force wave and the inherent modes of the support, so as to suppress resonance. Meanwhile, in cooperation with the axial thickness difference between the main spokes 12 and the auxiliary spokes 13, the low-order inherent frequencies are jointly promoted to shift to the target frequency band, realizing frequency shifting for vibration avoidance.

[0036] In the above technical solution: the number of the main spokes 12 is 5 to 12. The included angle between every two adjacent main spokes 12 is α. In this embodiment, the number of the main spokes 12 is 7, and the included angle α is 28.9°.

[0037] In the above technical solution, the outer end face of the main spoke 12 and the stator core 4 are interference fit.

[0038] In the above technical solution: the cylindrical base 11 has an inner hole 15 at its center. The support body 1 is fitted onto the central shaft 2 through the inner hole 15. Two bushings 3 are also fitted onto the central shaft 2, with the two bushings 3 located on opposite sides of the support body 1. The central shaft 2 has a cylindrical protrusion 21, with both ends of the protrusion 21 forming positioning step surfaces 22. The support body 1 is fitted onto the protrusion 21, and the sides of the two bushings 3 contact the two positioning step surfaces 22 respectively. The diameter of the inner hole 15 is D1, which is 36mm in this embodiment; the outer diameter of the cylindrical base 11 is D2, which is 50mm in this embodiment; and the diameter of the circumscribed circle of the support body 1 is D3, which is 218mm in this embodiment.

[0039] In the above technical solution: the support body 1 is made of lightweight metal material, preferably aluminum alloy or magnesium alloy, and is integrally formed by precision casting. This type of lightweight alloy material has both excellent specific strength (strength to density ratio) and good processing fluidity, which can meet the forming accuracy requirements of the mesh-like variable stiffness topology of the support body 1, while effectively reducing the unsprung mass of the motor. When higher load-bearing requirements are needed, 7075-T6 aluminum alloy with a yield strength of approximately 503 MPa can be selected; or additive manufacturing (3D printing) technology can be used to achieve a more complex topology optimization structure.

[0040] In the above technical solution: the main body 1 of the bracket is located inside the hub motor, and the hub motor is specifically an external rotor permanent magnet synchronous hub motor, which is applied to two-wheeled electric vehicles.

[0041] Compared to a solid disc structure with a uniform thickness of 30mm, the support body 1 in this invention effectively reduces weight by approximately 47%. This weight reduction causes the fourth natural frequency of the support body 1 to decrease from 1687.6Hz to 1314.3Hz. Corresponding to the 52nd order electromagnetic excitation force wave characteristics, its resonant speed decreases from 1947.2RPM outside the operating range to 1516.5RPM, falling within the rated and maximum operating speed range of 1500 to 1600RPM for the motor in this embodiment. Facing the aforementioned resonance coincidence condition, this invention employs an intrinsic amplitude suppression strategy instead of the traditional frequency avoidance design. Under the 1516.5RPM resonant excitation state, the variable stiffness topology with a stepped thickness distribution of 30mm to 20mm inside the support body 1 forms a mechanical impedance mismatch region.

[0042] Multiphysics simulations have verified that this embodiment reduces weight by approximately 47% compared to a solid structure of uniform thickness, while exhibiting extremely reliable static and dynamic service performance. Under static load conditions subject to ultimate stall torque, the maximum equivalent stress of the support body 1 is 113.21 MPa (e.g., Figure 5 As shown in the figure, it meets the requirements for basic support and high torque transmission strength.

[0043] For high-frequency dynamic conditions, this invention achieves intrinsic electromagnetic-structural decoupling through a variable stiffness topology. In harmonic response sweep analysis using a high-frequency electromagnetic excitation force with fourth-order spatial characteristics, the stepped thickness of this invention (30mm main spoke 12 and 20mm secondary spoke 13) creates a significant difference in mechanical impedance, effectively blocking the spatial coupling between the excitation force wave and the structural modes, and suppressing the dynamic response across the entire frequency band. Extracting the axial response of the secondary spoke 13 shows that within the target high-frequency band, the local maximum dynamic alternating normal stress induced by the electromagnetic force is only about 0.037 MPa, and the equivalent elastic strain is approximately... The maximum dynamic radial deformation of the stator support as a whole is within 0.0002mm.

[0044] In summary, the extremely small dynamic alternating stress is far below the high-cycle fatigue limit of lightweight metallic materials, and the submicron-level dynamic deformation is also far smaller than the safety air gap boundary between the stator and rotor. This invention, without introducing external damping elements, blocks the resonance excitation path through spatial topology optimization of the structure itself, completely eliminating the risk of fatigue fracture and motor stator swirl failure caused by high-frequency alternating loads. This achieves long-term safe service and extreme lightweighting of the stator support for the external rotor hub motor under extreme operating conditions.

[0045] The design method of the support body 1 includes the following steps: obtaining the target electromagnetic excitation frequency range of the hub motor; establishing a three-dimensional model of the support body 1, using the axial thickness of the main spokes 12, the axial thickness of the secondary spokes 13, the radius of the transition fillet 14, and the distribution number of the main spokes 12 as design variables; taking the spatial mode decoupling of the support body 1 within the target electromagnetic excitation frequency range, and the dynamic alternating stress and the maximum local equivalent stress under static load within the target frequency band being less than the preset material safety threshold as the target, adjusting the values ​​of the design variables to generate the final structural dimensions of the support body 1.

[0046] The step of "decoupling the spatial mode shape of the support body 1 within the target electromagnetic excitation frequency range" also includes performing modal analysis and harmonic response analysis on the support body 1 to verify whether the step thickness ratio of the main spokes 12 and the secondary spokes 13 meets the preset mode shape decoupling conditions.

[0047] The design variables also include the number of sub-spokes 13, the radial positions of each sub-spoke 13 from L1 to Ln, and the bending radii of each sub-spoke 13 from R1 to Rn, where n is the number of sub-spokes 13; the adjustment steps are optimized by finite element parametric scanning or multi-objective genetic algorithm.

[0048] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should fall within the protection scope of the present invention.

Claims

1. A stator support, comprising a support body (1), wherein a stator core (4) is sleeved on the support body (1), characterized in that... The main body (1) of the support includes a cylindrical base (11) and multiple main spokes (12). The multiple main spokes (12) are evenly distributed around the cylindrical base (11). One end of the main spoke (12) is connected to the outer circumferential surface of the cylindrical base (11), and the other end of the main spoke (12) is in contact with the inner circumferential surface of the stator core (4). A secondary spoke (13) is provided between any two adjacent main spokes (12). The two ends of the secondary spoke (13) are respectively connected to the opposite sides of the two adjacent main spokes (12). The axial thickness of the main spoke (12) is greater than the axial thickness of the secondary spoke (13). The secondary spokes (13) are arc-shaped; The center of the secondary spoke (13) bends toward the center of the support body (1) so that the secondary spoke (13) is arc-shaped; Multiple secondary spokes (13) are provided between two adjacent main spokes (12), and the multiple secondary spokes (13) between two adjacent main spokes (12) are arranged in an increasing manner in terms of curvature from the outside to the inside; Multiple secondary spokes (13) between two adjacent main spokes (12) are arranged in a decreasing manner from the outside to the inside in terms of bending radius; Multiple secondary spokes (13) between two adjacent main spokes (12) are arranged in a decreasing radial width from the outside to the inside; The circumferential width of the main spoke (12) gradually decreases from the outside to the inside.

2. A stator support according to claim 1, characterized in that... A transition fillet (14) is provided between the main spoke (12) and the stator core (4), and at the connection between the main spoke (12) and the secondary spoke (13).

3. A stator support according to claim 2, characterized in that... The radius of the transition fillet (14) is 0.5 mm to 2.0 mm.

4. A stator support according to claim 1, characterized in that... The ratio of the axial thickness of the main spoke (12) to the axial thickness of the secondary spoke (13) is 1.2:1 to 2.0:

1.

5. A stator support according to claim 1, characterized in that... The number of main spokes (12) is 5 to 12, and the number of secondary spokes (13) between two adjacent main spokes (12) is 2 to 6.

6. A stator support according to claim 1, characterized in that... The cylindrical base (11) has an inner hole (15) at its center. The bracket body (1) is fitted onto the central shaft (2) through the inner hole (15). Two bushings (3) are also fitted onto the central shaft (2). The two bushings (3) are located on both sides of the bracket body (1). The central shaft (2) has a cylindrical protrusion (21). The two ends of the protrusion (21) are positioning step surfaces (22). The bracket body (1) is fitted onto the protrusion (21). The sides of the two bushings (3) are in contact with the two positioning step surfaces (22).

7. A stator support according to claim 1, characterized in that... The bracket body (1) is integrally formed, and the outer end face of the main spoke (12) and the stator core (4) are interference fit. The bracket body (1) is located inside the hub motor.

8. A design method for a stator support as described in claim 2, characterized in that... The design method includes the following steps: obtaining the target electromagnetic excitation frequency range of the hub motor; establishing a three-dimensional model of the support body (1), and taking the axial thickness of the main spoke (12), the axial thickness of the secondary spoke (13), the radius of the transition fillet (14) and the number of main spokes (12) as design variables; taking the spatial mode decoupling of the support body (1) in the target electromagnetic excitation frequency range, and the dynamic alternating stress and the maximum equivalent stress of static load in the target frequency band as the target, adjusting the values ​​of the design variables, and generating the final structural dimensions of the support body (1).

9. The design method according to claim 8, characterized in that... The step of “decoupling the spatial mode shape of the support body (1) within the target electromagnetic excitation frequency range” also includes performing modal analysis and harmonic response analysis on the support body (1) to verify whether the step thickness ratio of the main spokes (12) and the secondary spokes (13) meets the preset mode shape decoupling conditions.

10. The design method according to claim 8, characterized in that... The design variables also include the number of sub-spokes (13), the radial position of each sub-spoke (13), and the bending radius of each sub-spoke (13). The adjustment steps are optimized by finite element parametric scanning or multi-objective genetic algorithm.

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