Torque calculation method of permanent magnet coupling high transmission torque detection device

Abstract

This invention belongs to the field of permanent magnet transmission technology and relates to a torque calculation method for a high transmission torque detection device for permanent magnet couplings. This torque calculation method is based on the magnetic energy method in the equivalent magnetic charge method. It equates the fan-ring type permanent magnet to a cuboid permanent magnet compatible with the magnetic energy method. Using the chain derivative method, the relative torque between a single pair of cuboid permanent magnets is calculated from the magnetic energy. Then, the relative torque between each pair of permanent magnets is traversed and linearly superimposed to obtain the relative torque between a pair of permanent magnet rings. Finally, a comprehensive correction coefficient is introduced to calculate the actual torque corresponding to different rotation angles of the inner and outer rotors of the permanent magnet coupling. The calculation method is simple and has high torque prediction accuracy, providing theoretical guidance for the iterative research on the performance of permanent magnet couplings.

Description

Technical Field

[0001] This invention belongs to the field of permanent magnet transmission technology and relates to a torque calculation method for a high transmission torque detection device for permanent magnet couplings. Background Technology

[0002] Permanent magnet couplings, as non-contact power transmission devices, achieve reliable transmission by using the magnetic field of permanent magnets as the force transmission medium. They offer advantages such as no mechanical wear, environmental friendliness, and excellent vibration isolation, and are widely used in high-end fields such as mining machinery, wind turbines, and ship shafting. Torque is the core indicator determining the transmission performance of permanent magnet couplings, directly influencing their operational reliability and performance stability, and is crucial for their design optimization, performance iteration, and engineering applications. However, existing torque loading mechanisms often utilize motors or cylinders to apply torque, which suffers from drawbacks such as torque pulses, vibration coupling, and electromagnetic interference, directly affecting the accuracy of permanent magnet coupling transmission performance testing and failing to meet the requirements of high-torque permanent magnet coupling performance testing scenarios. Therefore, there is an urgent need to develop a torque calculation method for high-torque detection devices of permanent magnet couplings, providing important technical support for the testing and evaluation of permanent magnet coupling transmission performance.

[0003] Regarding a high transmission torque detection device for permanent magnet couplings, Pei Yongchen, Xia Zhengrong, et al., in their patent "A device capable of realizing full-condition testing of synchronous and asynchronous magnetic couplings" (CN 110261104 B), used a stepper motor to apply torque and a six-axis force sensor to monitor the load torque of the magnetic coupling. Although it has static / dynamic testing functions, it has many series components and high requirements for motor power. Additional considerations are needed for testing accuracy, local temperature rise, design cost, and ease of operation. Therefore, designing a high transmission torque detection device for permanent magnet couplings that is highly applicable and easy to operate is of great significance for testing the transmission performance of permanent magnet couplings. Regarding a method for calculating high transmission torque in permanent magnet couplings, Li Jiangang of Jilin University, in his paper "Study on Magnetic Force and Magnetic Torque Between Permanent Magnets," proposed using permanent magnets and permanent magnet rings as research objects to construct analytical models of magnetic force and magnetic torque between permanent magnets and permanent magnet rings using the magnetic energy method. However, the magnetization direction and arrangement of the research objects are singular, making it unsuitable for permanent magnet rings composed of permanent magnets with alternating N and N poles and radial magnetization, thus hindering accurate evaluation of the transmission performance of permanent magnet couplings. Therefore, it is essential to provide a method for calculating high transmission torque in permanent magnet couplings. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a torque calculation method for a high-transmission torque detection device for permanent magnet couplings. The purpose is to utilize an integrated hydraulic station or high-pressure air pump to drive a torque arm in a telescopic motion. The resulting torque, acting on a loading plate, transforms from relative displacement into axial rotation. This torque is further transmitted to the outer rotor of the permanent magnet coupling, creating an angular difference with the fixed inner rotor. A torque sensor and an optical grating reading head measure the torque and relative rotation angle of the permanent magnet coupling in real time, obtaining the relationship between torque and relative rotation angle. This method is convenient to operate and offers high measurement accuracy, providing crucial technical support for testing the transmission performance of permanent magnet couplings and analyzing the sensitivity of performance parameters. Simultaneously, the invention also proposes a method for calculating the torque of a high-transmission torque detection device for permanent magnet couplings. The method for calculating high transmission torque of magnetic couplings is based on the equivalent magnetic charge method. It equates the fan-ring permanent magnet to a cuboid permanent magnet that is compatible with the magnetic energy method. The relative torque between a single pair of cuboid permanent magnets is calculated from the magnetic energy using the chain derivative method. Then, the relative torque between each pair of permanent magnets is traversed and linearly superimposed to obtain the relative torque between a pair of permanent magnet rings. Finally, a comprehensive correction coefficient is introduced to calculate the actual torque corresponding to different rotation angles of the inner and outer rotors of the permanent magnet coupling. The calculation method is simple and has high torque prediction accuracy, which has theoretical guiding significance for the iterative research on the performance of permanent magnet couplings.

[0005] The technical solution adopted in this invention is as follows: A method for calculating the torque of a high transmission torque detection device for permanent magnet couplings, comprising the following steps: Step 1: Build a high transmission torque detection device for permanent magnet couplings; The high transmission torque detection device for permanent magnet couplings includes a torque arm 1, a loading disk 2, a sliding shaft 1 3, a sliding bearing seat 1 4, a torque sensor 5, a sliding bearing seat 2 6, a sliding shaft 2 7, a grating strip 8, a permanent magnet coupling 9, a support shaft 10, a fixed base 11, a T-nut 12, a cast iron platform 13, a bracket 14, a grating strip reading head 15, a sliding bearing seat 2 base 16, a torque sensor base 17, and a sliding bearing seat 1 base 18. Torque arm 1, sliding bearing seat 2 base 16, torque sensor base 17, sliding bearing seat 1 base 18, fixed base 11, and bracket 14 are all fixedly connected to cast iron platform 13 via T-nuts 12. Torque arm 1 is driven by an integrated hydraulic station or high-pressure air pump, thereby controlling the extension and retraction distance of the piston rod, and is connected to loading plate 2 via a pin to provide axial torque. Sliding shaft 1 3 and sliding shaft 2 7 form sliding friction pairs with sliding bearing seat 1 4 and sliding bearing seat 2 6 respectively, releasing axial rotational freedom. Sliding bearing seat 1 4 and sliding bearing seat 2 6 are fixed on sliding bearing seat 1 base 18 and sliding bearing seat 2 base 16 respectively. Torque sensor 5 is connected to sliding shaft 1 3 and sliding shaft 2 7 via a flat key to monitor the applied torque value. Torque sensor 5 is fixed on torque sensor base 17. Grating strip 8 has reserved scale and is fixed by magnetic attraction or adhesive. The outer rotor back iron of the permanent magnet coupling 9 is fixed; the grating bar reading head 15 is bolted to the bracket 14 to read the scale on the grating bar 8 and calculate the output angle value to monitor the relative rotation angle between the inner and outer rotors of the permanent magnet coupling 9; the outer rotor of the permanent magnet coupling 9 is connected to the sliding shaft 7 by screws and pins, and the inner rotor of the permanent magnet coupling 9 is connected to the support shaft 10 by screws and pins; the support shaft 10 is connected to the fixed seat 11 by screws; the integrated hydraulic station or high-pressure air pump drives the torque arm 1, one of which extends outward and the other retracts inward. After both act on the loading plate 2, they generate axial torque, which is transmitted to the outer rotor of the permanent magnet coupling 9 through screw connection and flat key connection, forming a rotation angle difference with the fixed inner rotor of the permanent magnet coupling 9; the torque of the permanent magnet coupling 9 is tested by monitoring the torque change trend with the relative rotation angle in real time. The second step is to establish the mapping relationship between cuboid permanent magnets and sector-ring permanent magnets. The permanent magnets on the inner and outer rotors of the permanent magnet coupling 9 are fan-shaped, with the magnetization direction being radial. They are arranged with alternating N and S poles along the circumference and paired with each other along the radial direction, totaling 2. N Yes, it consists of an inner rotor permanent magnet ring and an outer rotor permanent magnet ring; the average radius of the fan-shaped inner rotor permanent magnet is specified. r 1 and the average radius of the outer rotor permanent magnet r 2. The thickness of both the inner rotor permanent magnet and the outer rotor permanent magnet is... m Both lengths are h Both polar arc angles are α The fan-ring shaped inner and outer rotor permanent magnets are divided into several cuboid permanent magnet micro-elements using the micro-element method. These micro-elements are then equivalent to the superposition of several cuboid permanent magnet micro-elements along their width, ultimately transforming the fan-ring shaped inner and outer rotor permanent magnets into cuboid inner and outer rotor permanent magnets. The length of the equivalent cuboid inner rotor permanent magnet is 2... a = hWidth 2 b = r 1 α High 2 c = m The length of the rectangular outer rotor permanent magnet is 2 A = h Width 2 B = r 2 α High 2 C = m ; The third step is to calculate the relative torque between the inner rotor permanent magnet and the outer rotor permanent magnet of a single pair of cuboids. At the geometric center of permanent magnet coupling 9 O Establish a global fixed coordinate system, coordinate axes X Along the axis of the permanent magnet coupling 9, coordinate axis Y with coordinate axes Z Along the radial direction of the permanent magnet coupling 9, where the coordinate axis Y The geometric centers of the inner and outer rotor permanent magnets pass through the cuboid, respectively; the relative positions between the geometric centers of the inner and outer rotor permanent magnets are represented by Δ. x Δ y Δ z This indicates that, based on the equivalent magnetic charge method, the interaction magnetic energy between the inner rotor permanent magnet and the outer rotor permanent magnet... W Represented as: in, J 1 and J 2 represents the magnetic polarization intensity of the inner rotor permanent magnet and the outer rotor permanent magnet, respectively. For a uniformly magnetized rare-earth permanent magnet, it is assumed that... J 1. J 2 is perpendicular to the surface of the magnetic pole, then J 1= J 2= B r , B r This represents the residual magnetic flux density of a permanent magnet; μ 0 represents the permeability of free space. μ 0 = 4π × 10 7 ; i , k , p This indicates the position number of each vertex of the internal rotor permanent magnet. j , l , q This indicates the position number of each vertex of the external rotor permanent magnet, which is either 0 or 1; u Let be the coordinate difference parameter along the length direction of each vertex of the inner rotor permanent magnet and the outer rotor permanent magnet. vLet be the coordinate difference parameter along the width direction between each vertex of the inner rotor permanent magnet and the outer rotor permanent magnet. w Let be the coordinate difference parameter along the height direction between each vertex of the inner rotor permanent magnet and the outer rotor permanent magnet. r The parameters represent the spatial geometric coordinate differences between the vertices of the inner rotor permanent magnet and the outer rotor permanent magnet, and each parameter is expressed as follows: u =Δ x +(-1) j A -(-1) i a , v =Δ y +(-1) l B -(-1) k b , w =Δ z +(-1) q C -(-1) p c , r =( u 2 + v 2 + w 2 ) 1 / 2 ; The relative torque between the inner and outer permanent magnets of a single cuboid is understood as the negative gradient of the interacting magnetic energy with respect to the relative rotation angle, and solved using the chain rule. Since only the axial torque of the permanent magnet coupling 9 is effective in the aligned state, and the torque in other directions is zero, the relative rotation angle is defined as follows. β Related only to axial torque; relative torque between the inner rotor permanent magnet and the outer rotor permanent magnet of a single cuboid. T 1 is represented as: in, W / β For interacting magnetic energy W relative angles β The partial derivatives can be further broken down into 6 partial derivative terms: W / u Represents the magnetic energy of interaction W The coordinate difference parameters of each vertex of the inner rotor permanent magnet and the outer rotor permanent magnet along the length direction u The partial derivative, W / vRepresents the magnetic energy of interaction W The coordinate difference parameters of each vertex of the inner rotor permanent magnet and the outer rotor permanent magnet along the width direction v The partial derivative, W / w Represents the magnetic energy of interaction W The coordinate difference parameters of each vertex of the inner rotor permanent magnet and the outer rotor permanent magnet along the height direction w The partial derivative, u / β This parameter represents the coordinate difference along the length direction between each vertex of the inner rotor permanent magnet and the outer rotor permanent magnet. u relative angles β The partial derivative, v / β This parameter represents the coordinate difference along the width direction between each vertex of the inner rotor permanent magnet and the outer rotor permanent magnet. v relative angles β The partial derivative, w / β This parameter represents the coordinate difference along the height direction between each vertex of the inner rotor permanent magnet and the outer rotor permanent magnet. w relative angles β The partial derivatives are further expressed as: in, θ This represents the instantaneous angular position of a cuboid permanent magnet element in the circumferential direction. For an inner rotor permanent magnet, θ =( x -1) α , x This indicates the location number of the permanent magnet in the inner rotor. x =1,2,...,2 N For external rotor permanent magnets, θ =( y -1) α , y This indicates the location number of the external rotor permanent magnet. y =1,2,...,2 N ; Step 4: Calculate the relative torque between a pair of permanent magnet rings; The inner rotor permanent magnet ring and the outer rotor permanent magnet ring are composed of 2 NThe system consists of permanent magnets arranged in a closely alternating N / S configuration along the circumferential direction. When an angular difference is formed between the inner and outer rotor permanent magnet rings, the inner rotor permanent magnet not only exerts a torque on the matched outer rotor permanent magnet but also on the outer rotor permanent magnet matched with its adjacent inner rotor permanent magnet. The interaction magnetic energy between the inner and outer rotor permanent magnet rings is a linear superposition of the interaction magnetic energy between each pair of inner and outer rotor permanent magnets. The torque between a pair of inner and outer rotor permanent magnet rings... T 2 represents the sum of the torques acting between each pair of inner rotor permanent magnets and outer rotor permanent magnets, expressed as: Among them, 2 N The number of pole pairs for the inner rotor permanent magnet and the outer rotor permanent magnet, which alternate between N and N poles; Step 5: Considering the structural characteristics, calculate the actual torque of the permanent magnet coupling 9; As can be seen from the structural features of the permanent magnet coupling 9, the inner rotor permanent magnet and the outer rotor permanent magnet need to be installed in a hub made of magnetically conductive 45 steel through precision machining. Because the spatially divergent magnetic lines of force are forcibly converged to the surface of the permanent magnet by the magnetically conductive material, the relative torque between the inner rotor permanent magnet ring and the outer rotor permanent magnet ring is amplified to more than twice the normal value. In addition, due to edge leakage, uneven magnetization, and end effects, the relative torque between the inner rotor permanent magnet ring and the outer rotor permanent magnet ring exhibits a trend of first significantly increasing and then slightly decreasing. A comprehensive correction coefficient is then introduced. ε =2.65 Correction of the relative torque between the inner rotor permanent magnet ring and the outer rotor permanent magnet ring, the corrected actual torque of the permanent magnet coupling 9 T 3 is represented as: .

[0006] The beneficial effect of this invention is that it proposes a torque calculation method for a high transmission torque detection device for permanent magnet couplings. The purpose is to utilize an integrated hydraulic station or high-pressure air pump to drive a torque arm in a telescopic motion. The generated torque, acting on the loading plate, transforms from relative displacement into axial rotation. When the torque is further transmitted to the outer rotor of the permanent magnet coupling, it forms an angular difference with the fixed inner rotor. A torque sensor and a grating bar reading head measure the torque and relative rotation angle of the permanent magnet coupling in real time, obtaining the relationship between torque and relative rotation angle. This method is convenient to operate and has high measurement accuracy. Simultaneously, the invention also proposes a permanent magnet... The method for calculating high transmission torque of couplings is based on the magnetic energy method in the equivalent magnetic charge method. It equates the fan-ring permanent magnet to a cuboid permanent magnet that is compatible with the magnetic energy method. The relative torque between a single pair of cuboid permanent magnets is calculated from the magnetic energy using the chain derivative method. Then, the relative torque between each pair of permanent magnets is traversed and linearly superimposed to obtain the relative torque between a pair of permanent magnet rings. Finally, a comprehensive correction coefficient is introduced to calculate the actual torque corresponding to different rotation angles of the inner and outer rotors of the permanent magnet coupling. The calculation method is simple and has high torque prediction accuracy, which has theoretical guiding significance for the iterative research on the performance of permanent magnet couplings. Attached Figure Description

[0007] Figure 1 This is a flowchart of the calculation method for high transmission torque of permanent magnet couplings; Figure 2 This is a schematic diagram of a high transmission torque detection device for permanent magnet couplings; Figure 3 It is a diagram showing the relative positions of a pair of rectangular permanent magnets; Figure 4 This is a graph showing the actual torque of a permanent magnet coupling as a function of the relative rotation angle between the inner and outer rotors. In the diagram, 1-torsion arm, 2-loading disk, 3-sliding shaft one, 4-sliding bearing seat one, 5-torque sensor, 6-sliding bearing seat two, 7-sliding shaft two, 8-grating strip, 9-permanent magnet coupling, 10-support shaft, 11-fixed seat, 12-T-nut, 13-cast iron platform, 14-bracket, 15-grating strip reading head, 16-base of sliding bearing seat two, 17-torque sensor base, 18-base of sliding bearing seat one. Detailed Implementation

[0008] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and technical solutions.

[0009] Example Select one inner and outer rotor with 2 evenly distributed circumferentially N =18 pairs of N / S pole alternating permanent magnets permanent magnet coupling 9, residual magnetic flux density of inner rotor permanent magnet and outer rotor permanent magnet B r =1.43T, average radius of the fan-shaped inner rotor permanent magnet r1=130.5mm, average radius of the fan-shaped outer rotor permanent magnet r 2 = 156.5mm, thickness m =17mm, length h =110mm, polar arc angle α =20°, relative rotation angle β The calculation points are incremented by 1 degree from 0 degrees to 20 degrees, for a total of 21 calculation points. like Figure 1 As shown, the torque calculation method for the high transmission torque detection device of permanent magnet couplings includes the following steps: Step 1: Build a high transmission torque detection device for permanent magnet couplings; The required T-nuts 12 are embedded into the pre-reserved slots of the cast iron platform 13; the fixed base 11, the sliding bearing seat 2 base 16, the torque sensor base 17, and the sliding bearing seat 18 are all connected to the cast iron platform 13 by four M16×60 socket head cap screws; the bracket 14 is connected to the cast iron platform 13 by one M16×60 socket head cap screw; the torque arm 1 foot is connected to the cast iron platform 13 by four M16×140 socket head cap screws; the torque arm 1 and the loading plate 2 are connected by a pin and limited by a shaft end retaining spring; the flange face of the sliding shaft 13 is secured by twelve M8×30 ​​socket head cap screws and six... A 10×35 internally threaded cylindrical pin connects to the loading disk 2. The optical shaft surface mates with the sliding bearing seat 4 to form a sliding friction pair. The optical shaft end face is connected to the torque sensor 5 via a 16×10 flat key. The optical shaft end face of the second sliding shaft 7 connects to the torque sensor 5 via a 16×10 flat key. The optical shaft surface mates with the sliding bearing seat 6 to form a sliding friction pair. The flange face utilizes 12 M8×30 ​​internal hexagon head screws and 6... A 10×35 internal thread cylindrical pin is connected to the outer rotor of the permanent magnet coupling 9; the grating strip 8 is fixed to the back iron of the outer rotor of the permanent magnet coupling 9 by magnetic attraction or adhesive; the grating strip reading head 15 is mounted on the bracket 14 by four M3×40 socket head cap screws; the flange face on one side of the support shaft 10 is secured by twelve M8×30 ​​socket head cap screws and six... A 10×35 internally threaded cylindrical pin connects to the inner rotor of the permanent magnet coupling 9. The other flange face is also connected via 12 M8×30 ​​socket head cap screws and 6… A 10×35 internally threaded cylindrical pin is connected to the fixed base 11; the sliding bearing seat 4 and the sliding bearing seat base 18, and the sliding bearing seat 6 and the sliding bearing seat base 16, are each connected by four M20×70 external hex bolts; the torque sensor base 17 and the torque sensor 5 are connected by four M12×40 internal hex head screws; thus, the high transmission torque detection device for permanent magnet couplings of the present invention is installed. Figure 2 As shown.

[0010] The second step is to establish the mapping relationship between cuboid permanent magnets and sector-ring permanent magnets. The equivalent rectangular cuboid has an inner rotor permanent magnet length of 2. a = h =110mm, width 2 b = r 1 α =45.56mm, height 2 c = m =17mm, the rectangular outer rotor permanent magnet is 2mm long. A = h =110mm, width 2 B = r 2 α =54.63mm, height 2 C = m =17mm; The relative positional relationship between the inner and outer rotor permanent magnets of a pair of rectangular parallelepipeds is as follows: Figure 3 As shown; The third step is to calculate the relative torque between the inner rotor permanent magnet and the outer rotor permanent magnet of a single pair of cuboids. The calculation results of the relative torque between the inner rotor permanent magnet and the outer rotor permanent magnet of a single pair of rectangular rotors are as follows: T 1-0 =0 N·m、 T 1-1 =8.15 N·m T 1-2 =20.47 N·m T 1-3 =24.57 N·m T 1-4 =29.49 N·m T 1-5 =34.72 N·m T 1-6 =39.01 N·m T 1-7 =40.68 N·m T 1-8 =42.11 N·m T 1-9 =44.92 N·m T 1-10 =43.85 N·m T 1-11 =47.46 N·m T 1-12 =43.93 N·m T 1-13 =42.16 N·m T 1-14 =42.35 N·mT 1-15 =40.68 N·m T 1-16 =39.56 N·m T 1-17 =36.25 N·m T 1-18 =31.98 N·m T 1-19 =27.39 N·m T 1-20 =24.06 N·m; Step 4: Calculate the relative torque between a pair of permanent magnet rings; Further calculations of the relative torque between the inner rotor permanent magnet ring and the outer rotor permanent magnet ring yielded the following results: T 2-0 =0 N·m、 T 2-1 =179.40 N·m T 2-2 =351.03 N·m T 2-3 =497.04 N·m T 2-4 =624.83 N·m T 2-5 =747.96 N·m T 2-6 =841.06 N·m T 2-7 =908.30 N·m T 2-8 =971.92 N·m T 2-9 =1026.57 N·m T 2-10 =1050.47 N·m T 2-11 =1059.64 N·m T 2-12 =1051.60 N·m T 2-13 =1030.40 N·m T 2-14 =969.26 N·m T 2-15 =878.45 N·m T 2-16 =764.51 N·m T 2-17 =618.89 N·m T 2-18 =426.36 N·mT 2-19 =225.72 N·m T 2-20 =0 N·m; Step 5: Considering the structural characteristics, calculate the actual torque of the permanent magnet coupling 9; Further introduce a comprehensive correction coefficient ε =2.65, the actual torque calculation results for the permanent magnet coupling 9 at each calculation point are as follows: T 3-0 =0 N·m、 T 3-1 =475.43 N·m T 3-2 =930.24 N·m T 3-3 =1317.15 N·m T 3-4 =1655.80 N·m T 3-5 =1982.10 N·m T 3-6 =2228.80 N·m T 3-7 =2407.00 N·m T 3-8 =2575.60 N·m T 3-9 =2720.40 N·m T 3-10 =2783.75 N·m T 3-11 =2808.05 N·m T 3-12 =2786.75 N·m T 3-13 =2730.55 N·m T 3-14 =2568.55 N·m T 3-15 =2327.90 N·m T 3-16 =2025.95 N·m T 3-17 =1640.05 N·m T 3-18 =1129.85 N·m T 3-19 =598.15 N·m T 3-20 =0 N·m, the actual torque varies with the relative angle as shown in the curve. Figure 4 As shown; This method is based on the magnetic energy method in the equivalent magnetic charge method. First, the fan-ring type permanent magnet is equivalent to a cuboid permanent magnet that is compatible with the magnetic energy method, and the associated parameters are mapped. Then, the negative gradient principle of magnetic energy with respect to relative rotation angle is used, combined with the chain rule to calculate the relative torque between a single pair of cuboid permanent magnets. Then, considering the interaction between adjacent permanent magnets, the relative torque between a pair of permanent magnet rings is calculated. Finally, a comprehensive correction coefficient is introduced to obtain the actual torque corresponding to different rotation angles of the inner and outer rotors of the permanent magnet coupling. The method is simple and has high torque prediction accuracy, which has theoretical guiding significance for the iterative research on the performance of permanent magnet couplings.

Claims

1. A torque calculation method of a high transmission torque detection device of a permanent magnet coupling, characterized by, The steps are as follows: Step 1: Build a high transmission torque detection device for permanent magnet couplings; The second step is to establish the mapping relationship between cuboid permanent magnets and sector-ring permanent magnets. Step 3: Calculate the relative torque between the inner rotor permanent magnet and the outer rotor permanent magnet of a single pair of cuboids; Step 4: Calculate the relative torque between a pair of permanent magnet rings; Step 5: Considering the structural characteristics, solve for the actual torque of the permanent magnet coupling (9).

2. The torque calculation method of the high transmission torque detection device of the permanent magnet coupling according to claim 1, characterized by, The high transmission torque detection device for permanent magnet coupling includes a torque arm (1), a loading disk (2), a sliding shaft one (3), a sliding bearing seat one (4), a torque sensor (5), a sliding bearing seat two (6), a sliding shaft two (7), a grating strip (8), a permanent magnet coupling (9), a support shaft (10), a fixed seat (11), a T-nut (12), a cast iron platform (13), a bracket (14), a grating strip reading head (15), a sliding bearing seat two base (16), a torque sensor base (17), and a sliding bearing seat one base (18). Torque arm (1), sliding bearing seat 2 base (16), torque sensor base (17), sliding bearing seat 1 base (18), fixed seat (11), and bracket (14) are all fixedly connected to the cast iron platform (13) by T-nut (12); Torque arm (1) is driven by an integrated hydraulic station or high-pressure air pump, thereby controlling the extension and retraction distance of the piston rod, and is connected to the loading plate (2) by a pin to provide axial torque; Sliding shaft 1 (3) and sliding shaft 2 (7) form sliding friction pairs with sliding bearing seat 1 (4) and sliding bearing seat 2 (6) respectively, releasing axial rotational freedom; Sliding bearing seat 1 (4) and sliding bearing seat 2 (6) are fixed on sliding bearing seat 1 base (18) and sliding bearing seat 2 base (16) respectively; Torque sensor (5) is connected to sliding shaft 1 (3) and sliding shaft 2 (7) by a flat key, used to monitor the applied torque value; Torque sensor (5) is fixed on torque sensor base (17); Grating strip (8) has reserved scale, The outer rotor back iron of the permanent magnet coupling (9) is fixed by magnetic attraction or adhesive; the grating bar reading head (15) is installed on the bracket (14) by bolts, reads the scale on the grating bar (8), and outputs the angle value by calculation to monitor the relative rotation angle between the inner and outer rotors of the permanent magnet coupling (9); the outer rotor of the permanent magnet coupling (9) is connected to the sliding shaft (7) by screws and pins, and the inner rotor of the permanent magnet coupling (9) is connected to the support shaft (10) by screws and pins; the support shaft (10) is connected to the fixed seat (11) by screws; the integrated hydraulic station or high-pressure air pump drives the torque arm (1), one of which extends outward and the other retracts inward. The two act on the loading plate (2) at the same time to generate axial torque, which is transmitted to the outer rotor of the permanent magnet coupling (9) through screw connection and flat key connection, forming a rotation angle difference with the fixed inner rotor of the permanent magnet coupling (9); the torque of the permanent magnet coupling (9) is tested by real-time monitoring of the torque change trend with the relative rotation angle.

3. The torque calculation method for the high transmission torque detection device of permanent magnet coupling according to claim 2, characterized in that, The specific implementation process of the second step is as follows: The permanent magnets on the inner and outer rotors of the permanent magnet coupling (9) are fan-shaped, with the magnetization direction being radial. They are arranged with alternating N and N poles along the circumference and paired with each other along the radial direction, totaling 2. N Yes, it consists of an inner rotor permanent magnet ring and an outer rotor permanent magnet ring; the average radius of the fan-shaped inner rotor permanent magnet is specified. r 1 and the average radius of the outer rotor permanent magnet r 2. The thickness of both the inner rotor permanent magnet and the outer rotor permanent magnet is... m Both lengths are h Both polar arc angles are α ; The fan-ring shaped inner and outer rotor permanent magnets are divided into several cuboid permanent magnet micro-elements using the micro-element method. The fan-ring shaped inner and outer rotor permanent magnets are equivalent to several cuboid permanent magnet micro-elements superimposed along the width direction, ultimately transforming the fan-ring shaped inner and outer rotor permanent magnets into cuboid inner and outer rotor permanent magnets. The length of the equivalent cuboid inner rotor permanent magnet is 2... a = h Width 2 b = r 1 α High 2 c = m The length of the rectangular outer rotor permanent magnet is 2 A = h Width 2 B = r 2 α High 2 C = m .

4. The torque calculation method of the high transmission torque detection device for permanent magnet couplings according to claim 3, characterized in that, The specific implementation process of the third step is as follows: At the geometric center of the permanent magnet coupling (9) O Establish a global fixed coordinate system, coordinate axes X Along the axis of the permanent magnet coupling (9), coordinate axis Y with coordinate axes Z Along the radial direction of the permanent magnet coupling (9), where the coordinate axis Y The geometric centers of the inner and outer rotor permanent magnets pass through the cuboid, respectively; the relative positions between the geometric centers of the inner and outer rotor permanent magnets are represented by Δ. x Δ y Δ z This indicates that, based on the equivalent magnetic charge method, the interaction magnetic energy between the inner rotor permanent magnet and the outer rotor permanent magnet... W Represented as: in, J 1 and J 2 represents the magnetic polarization intensity of the inner rotor permanent magnet and the outer rotor permanent magnet, respectively. For a uniformly magnetized rare-earth permanent magnet, it is assumed that... J 1. J 2 is perpendicular to the surface of the magnetic pole, then J 1= J 2= B r , B r This represents the residual magnetic flux density of a permanent magnet; μ 0 represents the permeability of free space. μ 0 = 4π × 10 7 ; i , k , p This indicates the position number of each vertex of the internal rotor permanent magnet. j , l , q This indicates the position number of each vertex of the external rotor permanent magnet, which is either 0 or 1; u Let be the coordinate difference parameter along the length direction of each vertex of the inner rotor permanent magnet and the outer rotor permanent magnet. v Let be the coordinate difference parameter along the width direction between each vertex of the inner rotor permanent magnet and the outer rotor permanent magnet. w Let be the coordinate difference parameter along the height direction between each vertex of the inner rotor permanent magnet and the outer rotor permanent magnet. r The parameters represent the spatial geometric coordinate differences between the vertices of the inner rotor permanent magnet and the outer rotor permanent magnet, and each parameter is expressed as follows: u =Δ x +(-1) j A -(-1) i a , v =Δ y +(-1) l B -(-1) k b , w =Δ z +(-1) q C -(-1) p c , r =( u 2 + v 2 + w 2 ) 1 / 2 ; The relative torque between the inner and outer permanent magnets of a single cuboid is understood as the negative gradient of the interacting magnetic energy with respect to the relative rotation angle, and is solved using the chain rule. Since only the axial torque of the permanent magnet coupling (9) is effective in the centering state, and the torque in other directions is zero, the relative rotation angle is defined as follows. β Related only to axial torque; relative torque between the inner and outer rotor permanent magnets of a single cuboid. T 1 is represented as: in, W / β For interacting magnetic energy W relative angles β The partial derivative is further broken down into 6 partial derivative terms: W / u Represents the magnetic energy of interaction W The coordinate difference parameters of each vertex of the inner rotor permanent magnet and the outer rotor permanent magnet along the length direction u The partial derivative, W / v Represents the magnetic energy of interaction W The coordinate difference parameters of each vertex of the inner rotor permanent magnet and the outer rotor permanent magnet along the width direction v The partial derivative, W / w Represents the magnetic energy of interaction W The coordinate difference parameters of each vertex of the inner rotor permanent magnet and the outer rotor permanent magnet along the height direction w The partial derivative, u / β This parameter represents the coordinate difference along the length direction between each vertex of the inner rotor permanent magnet and the outer rotor permanent magnet. u relative angles β The partial derivative, v / β This parameter represents the coordinate difference along the width direction between each vertex of the inner rotor permanent magnet and the outer rotor permanent magnet. v relative angles β The partial derivative, w / β This parameter represents the coordinate difference along the height direction between each vertex of the inner rotor permanent magnet and the outer rotor permanent magnet. w relative angles β The partial derivatives are further expressed as: in, θ This represents the instantaneous angular position of a cuboid permanent magnet element in the circumferential direction. For an inner rotor permanent magnet, θ =( x -1) α , x This indicates the location number of the permanent magnet in the inner rotor. x =1,2,...,2 N For external rotor permanent magnets, θ =( y -1) α , y This indicates the location number of the external rotor permanent magnet. y =1,2,...,2 N .

5. The torque calculation method for the high transmission torque detection device for permanent magnet couplings according to claim 4, characterized in that, The specific implementation process of the fourth step is as follows: The inner rotor permanent magnet ring and the outer rotor permanent magnet ring are composed of 2 N The system consists of permanent magnets arranged in a closely alternating N / S configuration along the circumferential direction. When an angular difference is formed between the inner and outer rotor permanent magnet rings, the inner rotor permanent magnet not only exerts a torque on the matched outer rotor permanent magnet but also on the outer rotor permanent magnet matched with its adjacent inner rotor permanent magnet. The interaction magnetic energy between the inner and outer rotor permanent magnet rings is a linear superposition of the interaction magnetic energy between each pair of inner and outer rotor permanent magnets. The torque between a pair of inner and outer rotor permanent magnet rings... T 2 represents the sum of the torques acting between each pair of inner rotor permanent magnets and outer rotor permanent magnets, expressed as: Among them, 2 N denoted as the number of pole pairs of the inner rotor permanent magnet and the outer rotor permanent magnet with alternating N and N poles.

6. The torque calculation method for the high transmission torque detection device for permanent magnet couplings according to claim 5, characterized in that, The specific implementation process of step five is as follows: As can be seen from the structural characteristics of the permanent magnet coupling (9), the inner rotor permanent magnet and the outer rotor permanent magnet need to be installed in the hub made of magnetically conductive 45 steel through precision machining. Since the spatially divergent magnetic lines of force are forcibly gathered to the surface of the permanent magnet by the magnetically conductive material, the relative torque between the inner rotor permanent magnet ring and the outer rotor permanent magnet ring is strengthened to more than twice. In addition, due to edge leakage, uneven magnetization and end effect, the relative torque between the inner rotor permanent magnet ring and the outer rotor permanent magnet ring shows a trend of first increasing significantly and then decreasing slightly. A comprehensive correction coefficient is introduced. ε =2.65 Correction of the relative torque between the inner rotor permanent magnet ring and the outer rotor permanent magnet ring, the corrected permanent magnet coupling (9) actual torque T 3 is represented as: 。

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