A device and a method for testing the magnetic force between permanent magnets in all directions

Abstract

The application belongs to the technical field of magnetic parameter measurement, and discloses a device and a calculation method for testing magnetic force in each direction between permanent magnets. The device uses an electric sliding table and a vertical sliding table to construct a three-dimensional motion platform, and collects the magnetic force of a tile-shaped permanent magnet under different spatial displacements in real time through a sensor. The device can not only meet the force testing needs of the inner / outer rotor permanent magnet under the axial, radial and tangential misalignment states, but also can adapt to different sizes of the inner / outer rotor permanent magnet by adjusting the clamp. Meanwhile, the magnetic force calculation method proposed by the application takes the equivalent magnetic charge model under the cylindrical coordinate system as the theoretical basis, and accurately solves the three-dimensional magnetic force of the inner / outer rotor permanent magnet under any spatial relative position through quadruple integration. With the help of the testing device and the calculation model proposed by the application, the precise measurement and theoretical verification of the magnetic force in each direction of the permanent magnet can be realized, the calculation is simple, and the degree of coincidence is high. The testing and calculation method has engineering universality and convenience.

Description

Technical Field

[0001] This invention belongs to the field of magnetic parameter measurement technology, and relates to a device and calculation method for testing the magnetic force between permanent magnets in all directions. Background Technology

[0002] The magnetic force between permanent magnets is a core physical quantity in various magnetic levitation support structures, permanent magnet couplings, magnetic actuators, and multi-physics coupled magnetic mechanisms. Especially in rotary magnetic transmission and magnetic load-bearing mechanisms, fan-ring permanent magnets are widely used as the core excitation element to achieve compact structural design and optimize air gap magnetic flux density. The relative position of the permanent magnets in three-dimensional space (including axial offset, radial offset, and angular difference) directly affects the magnitude and direction of the magnetic force. These changes in magnetic force further affect the motion state, stiffness characteristics, and stability of the magnetic field testing device. Therefore, accurately measuring the anisotropic forces between permanent magnets has significant engineering application value for magnetic mechanism design, magnetic loading system modeling, magnetic structure optimization, and device performance verification.

[0003] Regarding magnetic force testing devices for permanent magnets, Zheng Yan, Zhang Kaifei, and others, in their patent "A Magnetic Pole Detection Mechanism" (CN223108043 U), used an adjustment mechanism to drive a standard magnetic strip to rotate to match the magnetic poles, and utilized a cylinder to fix the product under test, with an electric push rod and a force gauge to achieve separation and detection of the product from the magnetic strip. However, this mechanism is mainly designed for regular strip-shaped magnets such as refrigerator door seals, focusing on discrete detection of unidirectional pull-out force. It lacks the ability to continuously measure the multi-dimensional forces on fan-ring permanent magnets in three-dimensional space, and its structure cannot meet the strict constraints and precise fine-tuning requirements of the degrees of freedom of large-attractive magnets in high-precision assembly scenarios. Therefore, providing a versatile tooling that can accurately control and measure the assembly forces of fan-ring permanent magnets through a three-dimensional motion platform is of great significance for the research of permanent magnet transmission equipment. Regarding methods for calculating anisotropic magnetic forces, He Yunxiang, in his paper "Research on Efficient Calculation of Electromagnetic Force in Transformer Windings Based on Response Surface Method," constructed a response surface surrogate model to replace the time-consuming finite element electromagnetic field simulation and used numerical fitting techniques to achieve rapid calculation of electromagnetic forces. However, this method is essentially a numerical approximation based on discrete sample data, failing to provide an analytical model based on physical field mechanisms. It is difficult to accurately describe the anisotropic force characteristics of a fan-ring permanent magnet under complex three-dimensional misalignment, and it is easily affected by sample quality, leading to fitting errors when dealing with highly nonlinear regions such as extremely small air gaps. Therefore, it is essential to establish a method suitable for fan-ring permanent magnets that can overcome the difficulties in calculating complex geometric boundaries and accurately predict assembly driving forces. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, this invention provides a device and calculation method for testing the magnetic force between permanent magnets in all directions. The aim is to achieve independent and precise adjustment of the permanent magnets in the axial and radial directions through a combination of a horizontal electric slide and a vertical slide; to ensure the stability of the magnets during testing through a high-rigidity clamping structure and a magnetic groove pressure plate; to achieve real-time acquisition of triaxial forces through a three-dimensional force sensor; and to establish a force calculation model of the interaction between two permanent magnets in three-dimensional space based on the equivalent magnetic charge method. Analytical expressions for the forces in all directions are obtained through surface element integration, ultimately achieving magnetic force calculation. This method solves the problems of difficult-to-accurate acquisition of the interaction force of permanent magnets and insufficient verification conditions for the magnetic force model, providing a reliable data foundation and theoretical support for the characterization of magnetic properties, magnetic force prediction, and research on magnetic field coupling laws in permanent magnet systems such as permanent magnet couplings.

[0005] The technical solution of the present invention:

[0006] A magnetic force testing device for permanent magnets includes a test platform, an electric slide table, a slide table slider, a vertical slide table base, a vertical slide table, a slider, a scale on the side of the vertical slide table, a self-locking device for the vertical slide table, a height adjustment device for the vertical slide table, a connecting plate, a sensor adapter plate, a three-dimensional force sensor, an adapter plate between the force sensor and the outer rotor magnet slot, an outer rotor magnet slot, an outer rotor permanent magnet, an inner rotor permanent magnet, a magnet slot pressure plate, and an inner rotor magnet slot.

[0007] The test platform is horizontally fixed on the ground. An electric slide table is installed on the upper surface of the test platform. The inner rotor magnet slot is connected to the slide block on the electric slide table, causing the inner rotor magnet slot to reciprocate axially with the slide block. The inner rotor permanent magnet is embedded in the inner rotor magnet slot, and magnet slot pressure plates are fixed on both sides of the inner rotor magnet slot to achieve clamping and limiting of the inner rotor permanent magnet. A vertical slide table base is fixed on the upper surface of the test platform, and its relative position to the electric slide table is adjusted. The vertical slide table is installed on the vertical slide table base, and a connecting plate is connected to the slide block on the vertical slide table. A scale is fixed to the side of the vertical slide table. The self-locking device of the vertical slide table is installed on the rear surface of the vertical slide table. The height adjustment device of the vertical slide table is installed on the upper surface of the vertical slide table. The sensor adapter plate is installed on the connecting plate. The fixed end of the three-dimensional force sensor is connected to the sensor adapter plate. The measuring end of the three-dimensional force sensor is connected to the outer rotor magnet slot through the adapter plate between the force sensor and the outer rotor magnet slot. The outer rotor permanent magnet is embedded in the outer rotor magnet slot, completing the alignment and assembly of the inner rotor permanent magnet and the outer rotor permanent magnet and the construction of the anisotropic magnetic force test between the permanent magnets.

[0008] A method for calculating the anisotropic magnetic force using the aforementioned anisotropic magnetic force testing device between permanent magnets, comprising the following steps:

[0009] The first step is to establish a spatial geometric mapping model in a global Cartesian coordinate system.

[0010] Establish a global Cartesian coordinate system O - XYZ Local cylindrical coordinate system of the inner rotor permanent magnet O 1- R 1 i 1 X 1. Local cylindrical coordinate system of the external rotor permanent magnet O 2- R 2 i 2 X 2; Convert the three-dimensional spatial deviation into relative position vectors and linear distances between infinitesimal elements; specifically as follows:

[0011] Establish a global Cartesian coordinate system O - XYZ As a spatial reference, the origin O Let X be the geometric center point of the inner rotor permanent magnet, X be the axial direction of the inner rotor permanent magnet, Y be the transverse direction of the inner rotor permanent magnet, and Z be the radial direction of the inner rotor permanent magnet; establish local cylindrical coordinate systems for the inner rotor permanent magnet and the outer rotor permanent magnet respectively:

[0012] The internal rotor permanent magnet is defined in the local cylindrical coordinate system. O 1- R 1 i 1 X 1 middle: origin O 1 and the origin of the global Cartesian coordinate system O The X1 direction is the axial direction of the inner rotor permanent magnet, and the R1 direction is the radial direction of the inner rotor permanent magnet.

[0013] Radial range: ,in, R in1 This indicates the inner radius of the internal rotor permanent magnet. R out1 Indicates the outer radius of the inner rotor permanent magnet;

[0014] Angular range: ,in, α The pole arc angle of the inner rotor permanent magnet;

[0015] Axial range: ,in, L 1 represents the axial length of the inner rotor permanent magnet;

[0016] The external rotor permanent magnet is defined in the local cylindrical coordinate system. O 2- R 2 i 2 X 2 medium: origin O 2 Relative to the origin O The spatial offset of 1 is ( ex , e y , z 0), X2 direction is the axial direction of the outer rotor permanent magnet, and R2 direction is the radial direction of the outer rotor permanent magnet;

[0017] Radial range: ,in, R in2 Indicates the inner radius of the outer rotor permanent magnet. R out2 Indicates the outer radius of the external rotor permanent magnet;

[0018] Angular range: ,in, β The pole arc angle of the external rotor permanent magnet;

[0019] Axial range: ,in, L 2 represents the axial length of the external rotor permanent magnet;

[0020] Axial displacement based on electric slide table e x Lateral eccentricity determined by the installation reference e y And the vertical displacement of the vertical slide table z 0; Let the relative position vector of any infinitesimal point P1(r1,θ1,x1) on the inner rotor permanent magnet and any infinitesimal point P2(r2,θ2,x2) on the outer rotor permanent magnet be r. 12 In the global Cartesian coordinate system, the three components of this relative position vector, ΔX, ΔY, and ΔZ, are as follows:

[0021]

[0022] The linear distance between infinitesimal points P1(r1,θ1,x1) and P2(r2,θ2,x2) is the modulus:

[0023] .

[0024] The second step is to develop a three-dimensional analytical integral model of magnetic force based on the equivalent magnetic charge of the pole surfaces.

[0025] Based on the equivalent magnetic charge method and Coulomb's law, the macroscopic magnetic force between the inner rotor permanent magnet and the outer rotor permanent magnet is regarded as the vector sum of the Coulomb forces between countless infinitesimal points on the magnetic pole surface. Through quadruple analytical integration, the axial force, lateral force and radial force of the outer rotor permanent magnet (15) and the inner rotor permanent magnet (16) are decoupled and solved; as follows:

[0026] Assume that both the inner and outer rotor permanent magnets are magnetized radially, and the remanence of the inner rotor permanent magnet is... Br1 The residual magnetism of the outer rotor permanent magnet is B r2 The vacuum permeability is m 0, then the magnetization intensity M Defined as:

[0027]

[0028] in, B r Residual magnetism of the inner rotor permanent magnet B r1 Or the residual magnetism of the external rotor permanent magnet B r2 ;

[0029] Based on the electromagnetic field boundary conditions, the equivalent surface magnetic charge density From magnetization M The dot product with the surface normal vector n determines: The magnetic charge is mainly distributed on the inner and outer cylindrical surfaces of the inner rotor permanent magnet and the outer rotor permanent magnet; the magnetization intensity of the inner rotor permanent magnet is... M 1. The magnetization intensity of the external rotor permanent magnet is M 2; The magnetization is positive on the N pole face and negative on the S pole face. The equivalent surface magnetic charge densities of the inner rotor permanent magnet and the outer rotor permanent magnet on the corresponding pole faces are as follows:

[0030]

[0031]

[0032] magnetization intensity M Substituting into the above equation, we get:

[0033]

[0034]

[0035] Take a micro-element of the inner rotor surface dS 1 With the micro-element of the outer rotor surface dS 2 According to the equivalent magnetic charge method, the surface micro-elements of the inner rotor... dS 1 With the micro-element of the outer rotor surface dS 2 The magnetic charge quantities are respectively:

[0036]

[0037]

[0038] According to Coulomb's law of magnetic charge, the infinitesimal element on the surface of the inner rotor is obtained. dS 1 With the micro-element of the outer rotor surface dS 2 Interaction forces between them:

[0039]

[0040] Further processing yields the following magnetic charge:

[0041]

[0042]

[0043] Substituting the obtained magnetic charge into the interaction force after further processing, we get:

[0044]

[0045] In the local cylindrical coordinate system, the infinitesimal element of the inner rotor surface dS 1 Expand as R 1 dth 1 dx 1. Micro-elements on the surface of the outer rotor dS 2 Expand as R 2 dth 2 dx 2. Substituting into the above formula, we get:

[0046]

[0047] Formula for calculating quadratic analytical integrals:

[0048] The total magnetic force vector F on the outer rotor is the sum of the integrals of the infinitesimal forces on all interacting surfaces; since the inner and outer rotors each have two main radial pole surfaces: the inner diameter surface and the outer diameter surface, the total magnetic force is the superposition of the integrals of the four sets of interacting surfaces.

[0049] The three forces are as follows:

[0050]

[0051]

[0052]

[0053] in, F x For axial force, F y For lateral force, F z Radial force; R 1i and R2j These represent the boundary radii of the inner rotor permanent magnet and the outer rotor permanent magnet, respectively; subscript i , j ∈{1,2} is used for the inner and outer radius surfaces of the inner rotor permanent magnet and the outer rotor permanent magnet, respectively, where 1 represents the inner radius surface and 2 represents the outer radius surface; for the inner rotor permanent magnet 16: R 11 inner radius R in1 , R 12 outer radius R out1 For the external rotor permanent magnet 15: R 21 inner radius R in2 , R 22 outer radius R out2 .

[0054] The beneficial effects of this invention are that, through the combination of an electric slide table and a vertical slide table, the device achieves independent and precise adjustment of the permanent magnet in the axial and vertical directions. Combined with a three-dimensional force sensor to collect triaxial force data in real time, it can effectively capture lateral forces and overturning torques caused by installation errors or magnet eccentricity, significantly enhancing the richness and comprehensiveness of the test data. This invention improves upon the traditional approximation method of simplifying tile-shaped magnets to rectangles, establishing a precise quadruple integral model based on a local cylindrical coordinate system. This effectively reduces calculation errors introduced by differences in geometric descriptions and improves the characterization accuracy of the physical properties of arc-shaped permanent magnets in practical engineering applications such as motor rotors. The device, combined with a high-rigidity dovetail clamping structure, ensures the safety and repeatability of the testing process. The calculation model obtained based on this model can perform high-precision extrapolation prediction of magnetic forces in test blind areas or dangerous areas such as extremely small air gaps, providing a reliable theoretical verification method for the optimized design of permanent magnet levitation, magnetic gears, and precision magnetic drive mechanisms. Attached Figure Description

[0055] Figure 1 This is a schematic diagram of the overall structure of the permanent magnet inter-magnetic force testing device.

[0056] Figure 2 This is a schematic diagram showing the connection between the inner and outer rotor magnet slot structure and the three-dimensional force sensor.

[0057] Figure 3 This is a schematic diagram of a calculation model for the interaction force between two permanent magnets based on the equivalent magnetic charge method.

[0058] Figure 4 This is a schematic diagram of the local cylindrical coordinate system of the internal rotor permanent magnet, where (a) is the front view and (b) is the right view.

[0059] Figure 5 This is a schematic diagram of a partial cylindrical coordinate system of an external rotor permanent magnet, where (a) is the front view and (b) is the right view.

[0060] In the diagram, 1-test platform, 2-electric slide table, 3-slide table slider, 4-vertical slide table base, 5-vertical slide table, 6-slider, 7-vertical slide table side scale, 8-vertical slide table self-locking device, 9-vertical slide table height adjustment device, 10-connecting plate, 11-sensor adapter plate, 12-three-dimensional force sensor, 13-adapter plate between force sensor and outer rotor magnet slot, 14-outer rotor magnet slot, 15-outer rotor permanent magnet, 16-inner rotor permanent magnet, 17-magnet slot pressure plate, 18-inner rotor magnet slot. Detailed Implementation

[0061] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and technical solutions.

[0062] Example

[0063] A magnetic force testing device for permanent magnets includes a test platform 1, an electric slide table 2, a slide table slider 3, a vertical slide table base 4, a vertical slide table 5, a slider 6, a scale on the side of the vertical slide table 7, a self-locking device for the vertical slide table 8, a height adjustment device for the vertical slide table 9, a connecting plate 10, a sensor adapter plate 11, a three-dimensional force sensor 12, an adapter plate 13 between the force sensor and the outer rotor magnet slot, an outer rotor magnet slot 14, an outer rotor permanent magnet 15, an inner rotor permanent magnet 16, a magnet slot pressure plate 17, and an inner rotor magnet slot 18.

[0064] The test platform 1 was horizontally fixed to the ground using M12 anchor bolts; the electric slide 2 was connected to the ground using M8×30 ​​cup head screws. A 6×20 positioning pin is installed on the upper surface of the test platform 1. The inner rotor magnet slot 18 is connected to the slide block 3 on the electric slide table 2 using M6×20 cup head screws, so that the inner rotor magnet slot 18 moves axially back and forth with the slide block 3. The inner rotor permanent magnet 16 is embedded in the dovetail groove of the inner rotor magnet slot 18. The magnet slot pressure plate 17 is locked to the reserved threaded holes on both sides of the inner rotor magnet slot 18 by M5×16 countersunk screws to achieve the clamping and limiting of the inner rotor permanent magnet 16. The vertical slide table base 4 is fixed to the upper surface of the test platform 1 by M8×35 cup head screws, and its relative position with the electric slide table 2 is adjusted. The vertical slide table 5 is installed on the vertical slide table base 4, and the connecting plate 10 is connected to the vertical slide table 5 by M6×20 cup head screws. The slider 6 is connected, the scale 7 on the side of the vertical slide table is fixed to the side of the vertical slide table 5, the self-locking device 8 of the vertical slide table is installed on the rear surface of the vertical slide table 5, the height adjustment device 9 of the vertical slide table is installed on the upper surface of the vertical slide table 5, the sensor adapter plate 11 is installed on the connecting plate 10 using M5×16 cup head screws, the fixed end of the three-dimensional force sensor 12 is connected to the sensor adapter plate 11 through M6×12 high strength screws; the measuring end of the three-dimensional force sensor 12 is connected to the outer rotor magnet slot 14 through the adapter plate 13 between the force sensor and the outer rotor magnet slot; the outer rotor permanent magnet 15 is embedded and installed in the outer rotor magnet slot 14, completing the alignment and assembly of the inner rotor permanent magnet 16 and the outer rotor permanent magnet 15 and the construction of the anisotropic magnetic force test between the permanent magnets.

[0065] Among them, vacuum permeability m 0 = 4π × 10 -7 H / m, remanence of permanent magnet Br =1.41T, corresponding to magnetization M =1.1×10 6 A / m; Outer radius of the 16mm inner rotor permanent magnet R out1 =139mm, inner radius of the inner rotor permanent magnet 16 R in1 =122mm; Outer radius of the outer rotor permanent magnet 15 R out2 =165mm, inner radius of the outer rotor permanent magnet 15 R in2 =148mm; the pole arc angle of both the inner rotor permanent magnet and the outer rotor permanent magnet is 20°, the axial length of both is 55mm, and the surface is nickel-copper-nickel plated; the repeatability of the electric slide is 0.01mm, the range of the three-dimensional force sensor is 500N, and the initial vertical air gap is set to... Z 0 = 9mm;

[0066] A method for calculating the magnetic force in all directions between permanent magnets, the steps of which are as follows:

[0067] The first step is to establish a spatial geometric mapping model in a global Cartesian coordinate system.

[0068] A spatial geometric mapping model of the inner rotor permanent magnet 16 and the outer rotor permanent magnet 15 is established. The geometric parameters of the inner rotor permanent magnet 16 are set as follows: inner radius... R in1 =122mm, outer radius R out1 =139mm, pole arc angle of the inner rotor permanent magnet α =20°, axial length L1=55mm, remanence Br 1 = 1.41T; The geometric parameters of the outer rotor permanent magnet 15 are set as follows: inner radius... R in2 =148mm, outer radius R out2 =165mm, Pole arc angle of external rotor permanent magnet β =20°, axial length L2=55mm, remanence Br 2 = 1.41T; The two magnets are set to always be tangentially aligned. e y =0mm) and vertical displacement Z 0 = 9mm;

[0069] The second step is to develop a three-dimensional analytical integral model of magnetic force based on the equivalent magnetic charge of the pole surfaces.

[0070] Selecting lateral eccentricity e x Three typical working conditions of 0mm, 10mm, and 20mm were used as calculation points P1, P2, and P3, respectively. The geometric parameters from the first step were substituted into the quadruple analytical integral calculation formula for solution. The calculation results show that: (1) Radial force F z : In the fully aligned working condition P1 ( e x =0mm) below, F z1 =370.8N; under moderate misalignment condition P2 ( e x =10mm) below, F z2 =314.4N; P3 under large misalignment condition ( e x =20mm) below, F z3 =221.3N. The results show that as the axial misalignment increases, the effective attraction area decreases, and the radial magnetic force exhibits a nonlinear decay trend. (2) Axial force F x With lateral force F ySubstituting into the integral formula, the axial forces corresponding to P1, P2, and P3 are respectively... F x =0.0N、 F x =106.2N F x =145.6N, verifying the characteristics of the axial restoring force generated by magnetic field misalignment; simultaneously, it was verified that the lateral force under the three working conditions is... F y =0N. Based on the above data, this step achieves a complete prediction of the force state of the permanent magnet in three-dimensional space.

[0071] This method characterizes the magnetic force of the spatial magnetic field by constructing an equivalent magnetic charge model in a local cylindrical coordinate system. It accurately obtains the three-dimensional force distribution of two permanent magnets at different axial positions, comprehensively reflects the coupling relationship between radial and axial magnetic forces as displacement changes, provides reliable data support for analyzing the interaction law between magnets, and is applicable to the calculation conditions of permanent magnets with common shapes. It is simple to calculate and is a calculation method with engineering universality and convenience.

Claims

1. A device for testing the magnetic force of permanent magnets in all directions, characterized in that, The permanent magnet inter-directional magnetic force testing device includes a test platform (1), an electric slide table (2), a slide table slider (3), a vertical slide table base (4), a vertical slide table (5), a slider (6), a scale on the side of the vertical slide table (7), a self-locking device for the vertical slide table (8), a height adjustment device for the vertical slide table (9), a connecting plate (10), a sensor adapter plate (11), a three-dimensional force sensor (12), an adapter plate between the force sensor and the outer rotor magnet slot (13), an outer rotor magnet slot (14), an outer rotor permanent magnet (15), an inner rotor permanent magnet (16), a magnet slot pressure plate (17) and an inner rotor magnet slot (18). The test platform (1) is fixed horizontally on the ground; the electric slide (2) is installed on the upper surface of the test platform (1), and the inner rotor magnet slot (18) is connected to the slide block (3) on the electric slide (2), so that the inner rotor magnet slot (18) moves back and forth along the axial direction with the slide block (3); the inner rotor permanent magnet (16) is embedded in the inner rotor magnet slot (18), and the magnet slot pressure plate (17) is fixed on both sides of the inner rotor magnet slot (18) to realize the pressing and limiting of the inner rotor permanent magnet (16); the vertical slide base (4) is fixed on the upper surface of the test platform (1), and its relative position with the electric slide (2) is adjusted; the vertical slide (5) is installed on the vertical slide base (4), and the connecting plate (10) is connected to the slider (6) on the vertical slide (5). Next, the scale (7) on the side of the vertical slide is fixed to the side of the vertical slide (5), the self-locking device (8) of the vertical slide is installed on the rear surface of the vertical slide (5), the height adjustment device (9) of the vertical slide is installed on the upper surface of the vertical slide (5), the sensor adapter plate (11) is installed on the connecting plate (10), and the fixed end of the three-dimensional force sensor (12) is connected to the sensor adapter plate (11); the measuring end of the three-dimensional force sensor (12) is connected to the outer rotor magnet slot (14) through the adapter plate (13) between the force sensor and the outer rotor magnet slot; the outer rotor permanent magnet (15) is embedded in the outer rotor magnet slot (14), thus completing the alignment and assembly of the inner rotor permanent magnet (16) and the outer rotor permanent magnet (15) and the construction of the magnetic force test between the permanent magnets.

2. A method for calculating the anisotropic magnetic force using the anisotropic magnetic force testing device between permanent magnets as described in claim 1, characterized in that, The steps are as follows: The first step is to establish a spatial geometric mapping model in a global Cartesian coordinate system. Establish a global Cartesian coordinate system O - XYZ Local cylindrical coordinate system of the inner rotor permanent magnet (16) O 1- R 1 θ 1 X 1. Local cylindrical coordinate system of the external rotor permanent magnet (15) O 2- R 2 θ 2 X 2; Convert the three-dimensional spatial deviation into relative position vectors and linear distances between infinitesimal elements; The second step is to develop a three-dimensional analytical integral model of magnetic force based on the equivalent magnetic charge of the pole surfaces. Based on the equivalent magnetic charge method and Coulomb's law, the macroscopic magnetic force between the inner rotor permanent magnet (16) and the outer rotor permanent magnet (15) is regarded as the vector sum of the Coulomb forces between countless micro-points on the magnetic pole surface. Through quadruple analytical integration, the axial force, lateral force and radial force of the outer rotor permanent magnet (15) and the inner rotor permanent magnet (16) are decoupled and solved.

3. The method for calculating the anisotropic magnetic force of the anisotropic magnetic force testing device between permanent magnets according to claim 2, characterized in that, The specific implementation process of the first step is as follows: Establish a global Cartesian coordinate system O - XYZ As a spatial reference, the origin O Let X be the geometric center of the inner rotor permanent magnet (16), X be the axial direction of the inner rotor permanent magnet (16), Y be the transverse direction of the inner rotor permanent magnet (16), and Z be the radial direction of the inner rotor permanent magnet (16); establish local cylindrical coordinate systems for the inner rotor permanent magnet (16) and the outer rotor permanent magnet (15) respectively: The internal rotor permanent magnet (16) is defined in the local cylindrical coordinate system. O 1- R 1 θ 1 X 1 middle: origin O 1 and the origin of the global Cartesian coordinate system O The X1 direction is the axial direction of the inner rotor permanent magnet (16), and the R1 direction is the radial direction of the inner rotor permanent magnet (16). Radial range: ,in, R in1 This represents the inner radius of the inner rotor permanent magnet (16). R out1 Indicates the outer radius of the inner rotor permanent magnet (16); Angular range: ,in, α The pole arc angle of the inner rotor permanent magnet; Axial range: ,in, L 1 represents the axial length of the inner rotor permanent magnet (16); The external rotor permanent magnet (15) is defined in the local cylindrical coordinate system. O 2- R 2 θ 2 X 2 medium: origin O 2. Relative to the origin O The spatial offset of 1 is ( e x , e y , z 0), X2 direction is the axial direction of the outer rotor permanent magnet (15), and R2 direction is the radial direction of the outer rotor permanent magnet (15); Radial range: ,in, R in2 Indicates the inner radius of the outer rotor permanent magnet (15). R out2 Indicates the outer radius of the outer rotor permanent magnet (15); Angular range: ,in, β The pole arc angle of the external rotor permanent magnet; Axial range: ,in, L 2 represents the axial length of the outer rotor permanent magnet (15); Axial displacement based on electric slide (2) e x Lateral eccentricity determined by the installation reference e y and the vertical displacement of the vertical slide (5) z 0; Let the relative position vector between any infinitesimal point P1(r1,θ1,x1) on the inner rotor permanent magnet (16) and any infinitesimal point P2(r2,θ2,x2) on the outer rotor permanent magnet (15) be r. 12 In the global Cartesian coordinate system, the three components of this relative position vector, ΔX, ΔY, and ΔZ, are as follows: The linear distance between infinitesimal points P1(r1,θ1,x1) and P2(r2,θ2,x2) is the modulus: 。 4. The method for calculating the anisotropic magnetic force of the anisotropic magnetic force testing device between permanent magnets according to claim 3, characterized in that, The specific implementation process of the second step is as follows: Assume that both the inner rotor permanent magnet (16) and the outer rotor permanent magnet (15) are magnetized radially, and the remanence of the inner rotor permanent magnet is... B r1 The residual magnetism of the outer rotor permanent magnet is B r2 The vacuum permeability is μ 0, then the magnetization intensity M Defined as: in, B r Residual magnetism of the inner rotor permanent magnet B r1 Or the residual magnetism of the external rotor permanent magnet B r2 ; Based on the electromagnetic field boundary conditions, the equivalent surface magnetic charge density From magnetization M The dot product with the surface normal vector n determines: The magnetic charge is mainly distributed on the inner and outer cylindrical surfaces of the inner rotor permanent magnet (16) and the outer rotor permanent magnet (15); the magnetization intensity of the inner rotor permanent magnet (16) is M 1. The magnetization intensity of the outer rotor permanent magnet (15) is M 2; The magnetization is positive on the N pole face and negative on the S pole face. The equivalent surface magnetic charge densities of the inner rotor permanent magnet (16) and the outer rotor permanent magnet (15) on the corresponding pole faces are as follows: magnetization intensity M Substituting into the above equation, we get: Take a micro-element of the inner rotor surface dS 1 With the micro-element of the outer rotor surface dS 2 According to the equivalent magnetic charge method, the surface micro-elements of the inner rotor... dS 1 With the micro-element of the outer rotor surface dS 2 The magnetic charge quantities are respectively: According to Coulomb's law of magnetic charge, the infinitesimal element on the surface of the inner rotor is obtained. dS 1 With the micro-element of the outer rotor surface dS 2 Interaction forces between them: Further processing yields the following magnetic charge: Substituting the obtained magnetic charge into the interaction force after further processing, we get: In the local cylindrical coordinate system, the infinitesimal element of the inner rotor surface dS 1 Expand as R 1 dθ 1 dx 1. Micro-elements on the surface of the outer rotor dS 2 Expand as R 2 dθ 2 dx 2. Substituting into the above formula, we get: Formula for calculating quadratic analytical integrals: The total magnetic force vector F on the outer rotor is the sum of the integrals of the infinitesimal forces on all interacting surfaces; since the inner and outer rotors each have two main radial pole surfaces: the inner diameter surface and the outer diameter surface, the total magnetic force is the superposition of the integrals of the four sets of interacting surfaces. The three forces are as follows: in, F x For axial force, F y For lateral force, F z Radial force; R 1i and R 2j These represent the boundary radii of the inner rotor permanent magnet (16) and the outer rotor permanent magnet (15), respectively; subscript i , j ∈{1,2} is used for the inner and outer radius surfaces of the inner rotor permanent magnet (16) and the outer rotor permanent magnet (15), where 1 represents the inner radius surface and 2 represents the outer radius surface; for the inner rotor permanent magnet (16): R 11 inner radius R in1 , R 12 outer radius R out1 For the external rotor permanent magnet (15): R 21 inner radius R in2 , R 22 outer radius R out2 .

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