Permanent magnet transmission device with magnets arranged in shape of Chinese character'ba 'and torque calculation method of permanent magnet transmission device

Abstract

The invention discloses a permanent magnet transmission device with magnets arranged in a splayed shape and a torque calculation method of the permanent magnet transmission device. According to the structure, tile-shaped magnetic steel is embedded into the inner wall of a hub of the power rotary drum, splayed permanent magnets are embedded into a hub of the load rotary core, and torque transmission is achieved through magnetic attraction force. A high-elasticity annular rubber air bag ring is installed in the power side sealing end cover, roller bearings are installed at the shaft necks of the power key groove shaft and the load key groove shaft, and axial vibration isolation and radial vibration isolation are achieved. Vortex distribution is reduced, torque transmission efficiency is improved, load change can be adapted by adjusting the slip angle of the inner rotor and the outer rotor, and the capacity of the system for coping with sudden working conditions is enhanced through the vibration isolation device. The torque calculation method is based on theories such as an equivalent magnetic charge method, two tile-shaped magnetic steels and a sandwiched splayed permanent magnet are taken as research objects, a double-Cartesian three-dimensional coordinate system is established, the magnetic charge surface density and the magnetic suction moment are solved, and the total output torque of the system is further obtained. According to the method, the complicated process of traditional finite element analysis is avoided, the torque can be rapidly and accurately solved, and the method has good universality.

Description

Technical Field

[0001] The present invention belongs to the technical field of mechanical transmission, and relates to a permanent magnet transmission device with an eight-character arrangement of magnets and a torque calculation method thereof. Background Art

[0002] In the field of industrial manufacturing, high-precision transmission devices are widely used in industries such as vehicle transportation, shipbuilding, and metallurgical chemistry, mainly for realizing torque transmission between the power source and the load to ensure the stable operation of the mechanical system. Traditional mechanical transmission devices have many deficiencies. For example, the friction loss is significant. When gears are in contact or chains are engaged with sprockets, the microscopic roughness of the contact surface will cause energy to be lost in the form of heat and cause wear of the mechanism. In addition, resonance may occur when the meshing frequency of the internal mechanism coincides with the natural frequency of the system. The overload tolerance is poor. Gear materials (such as quenched steel) have high hardness but low toughness, and are prone to brittle fracture under overload. Moreover, most mechanical transmissions are rigid connections and cannot achieve overload protection through slip. The emerging permanent magnet transmission device effectively solves the problems of large friction loss, frequent maintenance, and poor environmental adaptability in traditional mechanical transmission through non-contact energy transfer and flexible torque transmission characteristics, which is of great significance for ensuring the efficient operation of mechanical equipment. However, permanent magnet transmission devices generally face some challenges in structural design and torque calculation. Structurally, the magnetic circuit design is relatively complex, and it is difficult to accurately calculate and optimize the magnetic flux distribution, which easily leads to low magnetic field utilization rate and affects the transmission efficiency. Secondly, the arrangement and fixation methods of permanent magnets face challenges. It is necessary to ensure sufficient magnetic attraction force to achieve efficient transmission, and at the same time, consider the stability of permanent magnets under different working conditions to prevent the permanent magnets from loosening or shifting due to vibration, impact, etc., which reduces the performance of the transmission device. In terms of calculation, the torque solution of the permanent magnet transmission device often relies on finite element simulation technology, which requires coupling a large number of environmental parameters when constructing the simulation model and making detailed mesh division at key parts, making the calculation process extremely long and complex, and seriously reducing the calculation efficiency. Therefore, it is of crucial significance to propose a permanent magnet transmission device with a compact structure, stable performance, strong vibration isolation force, and strong torque transmission ability and its torque calculation method for promoting the theoretical research of permanent magnet transmission devices and realizing the diversification of transmission devices.

[0003] Regarding the structural design of the permanent magnet transmission device, J.A. Faulkner proposed in the patent "Lubricated Gear Coupling" (CN106715939B) to use the relative movement in the axial, radial, and angular directions between the first hub and the second hub arranged in the sleeve to achieve the purpose of torque transmission from the input shaft to the output shaft. However, due to the constraints of gear strength and other mechanical characteristics, this device has the deficiencies of weak speed change ability and small transmitted torque, and it is necessary to add lubricating oil regularly to reduce the friction loss between the hubs, which cannot meet the requirements of the system for long-term operation.

[0004] Regarding the torque calculation method of the permanent magnet drive device, Yang Chaojun obtained field quantities such as eddy current density, magnetic flux density, and torque in different time periods in the finite element model of a specific double-layer solid asynchronous magnetic coupling through electromagnetic field finite element simulation analysis in the article "Analysis of Eddy Current and Transmission Characteristics of Double-Layer Solid Asynchronous Magnetic Couplings". However, this method requires meticulous mesh division of the copper layer and air gap regions, resulting in a significant decrease in calculation efficiency. In addition, this method cannot handle the torque solution of other permanent magnet drive devices, and its universality and flexibility are restricted.

[0005] Therefore, it is very necessary to propose a permanent magnet drive device with low friction loss, strong torque transmission ability, and long-term stable operation, and a high-precision and highly universal calculation method for the permanent magnet drive device. Summary of the Invention

[0006] To make up for the deficiencies of the existing technology, the present invention proposes a permanent magnet drive device with an eight-shaped arrangement of magnets and its torque calculation method. By embedding tile-shaped permanent magnets in the inner wall fixing groove of the power rotating drum hub and embedding eight-shaped permanent magnets in the inner part of the load rotating core hub, the non-contact magnetic force generated between the two is used to achieve torque transmission between the power source and the load side, thereby reducing the contact friction of the system and achieving the purposes of improving efficiency, reducing noise, and increasing service life.

[0007] The technical solution of the present invention:

[0008] A permanent magnet drive device with an eight-shaped arrangement of magnets. First, embed the tile-shaped permanent magnets into the fixing groove on the inner wall of the power rotating drum hub, cover the two with the power rotating drum dust-proof cover, open an eight-shaped groove at a suitable position inside the load rotating core hub, embed the eight-shaped permanent magnets and cover them with the load rotating core sealing cover to achieve the limit and sealing of the permanent magnets; secondly, lock the high-elastic annular rubber airbag ring on the inner surface of the power side sealing end cover with fastening bolts, install roller bearings on the journal of the power keyway shaft and the load keyway shaft to complete the assembly of the axial and radial vibration isolation mechanisms; finally, fix the power keyway shaft and the load keyway shaft on both sides with specific bolts. Realize the purpose of driving the power keyway shaft to rotate by the power source and achieving system torque transmission under the magnetic suction force between the tile-shaped permanent magnets and the eight-shaped permanent magnets. When the rotational speed changes suddenly, the dislocation angle between the tile-shaped permanent magnets and the eight-shaped permanent magnets changes accordingly, thereby generating torques of different degrees, and further realizing the self-stabilizing adjustment of the system; the structure of the present invention is compact, the operation is convenient, there is no mechanical friction loss, the sound insulation performance is good, and the torque dynamic adaptability is good. It is suitable for scenarios with flexible load changes and has high engineering application and popularization value in the field of high-precision transmission.

[0009] A permanent magnet drive device with an eight-shaped arrangement of magnets, which is easy to assemble, has a stable structure and excellent vibration isolation performance. It includes a load keyway shaft, a load-side vibration isolation roller bearing, a tile-shaped permanent magnet, a power drum hub, a power drum dust-proof shell, a power-side seal end cover, a power-side vibration isolation roller bearing, a power keyway shaft, a high-elastic annular vibration isolation rubber airbag ring, a rotating core limit seal cover, a load rotating core hub, an eight-shaped permanent magnet and a load rotating core seal shell;

[0010] The load rotating core hub is internally provided with an eight-shaped groove and the eight-shaped permanent magnet is embedded therein. The load rotating core seal shell covers the outer surface of the load rotating core hub, and the two are fixed by bolts; the rotating core limit seal cover is fixed on the power side of the load rotating core seal shell by bolts; the inner wall of the power drum hub is grooved and the tile-shaped permanent magnet is embedded therein. The power drum dust-proof shell is sleeved on the surface of the power drum hub; the power-side seal end cover is fixed on the outside of the power drum dust-proof shell, and the power-side seal end cover, the power drum dust-proof shell and the power drum hub are fixedly connected by bolts; the high-elastic annular vibration isolation rubber airbag ring is locked in the cavity inside the power-side seal end cover by bolts and nuts; the power keyway shaft is fixed on the power-side seal end cover by bolts, and the load keyway shaft is movably connected to the load rotating core seal shell; the load-side vibration isolation roller bearing and the power-side vibration isolation roller bearing are respectively installed at the journal positions of the load keyway shaft and the power keyway shaft.

[0011] High-elastic O-shaped sealing washers are padded at all the bolt connection points mentioned above.

[0012] A torque calculation method for a permanent magnet drive device with an eight-shaped arrangement of magnets. Based on the layout characteristics of the permanent magnets of the device, taking two tile-shaped permanent magnets and the eight-shaped permanent magnet sandwiched between them as the research object, a double Cartesian three-dimensional coordinate system is established. Based on the equivalent magnetic charge method, linear space and linear transformation theory, the magnetic charge surface density on the surface of the permanent magnet material is solved by using multiple integrals. A dislocation angle is given to the two Cartesian coordinate systems, and the magnetic attraction torque between the two tile-shaped permanent magnets and the eight-shaped permanent magnet sandwiched between them is solved, and the total output torque of the system at the given dislocation angle is calculated from this, so as to obtain the output torque of the system at the given dislocation angle, realizing the rapid calculation of the torque and dislocation angle required for different loads, achieving the purpose of quickly adapting to changing scenarios, and providing important theoretical calculation support for the structural design and performance optimization of the permanent magnet drive device.

[0013] The specific steps are as follows:

[0014] The first step is to determine the key parameters of the permanent magnet drive device with an eight-shaped arrangement of magnets;

[0015] The key parameters include the remanent magnetization of the tile-shaped permanent magnet , the remanent magnetization of the eight-shaped permanent magnet , the vacuum permeability , the curvature radius of the tile-shaped permanent magnet , the curvature radius of the eight-shaped groove , the equivalent magnetic charge density of the lower surface of the tile-shaped permanent magnet along the coordinate axes , the equivalent magnetic charge surface density of the outer surface of the eight-shaped permanent magnet , the axial length of the hub of the power rotating cylinder , the axial length of the hub of the load rotating core and the coordinate transformation matrix ;

[0016] Step 2: Calculate the magnetic charge surface density of the tile-shaped permanent magnet and the eight-shaped permanent magnet;

[0017] Take the geometric center of the hub of the load rotating core as the origin, and make a cross-section Ω of the hub of the load rotating core passing through the origin. Arbitrarily select two adjacent tile-shaped permanent magnets, defined as the Pth tile-shaped permanent magnet and the Qth tile-shaped permanent magnet; take the direction of the line connecting the origin to the midpoint of the arc projected by the Pth tile-shaped permanent magnet and the Qth tile-shaped permanent magnet on the cross-section Ω as the X-axis and Y-axis directions, and establish a Cartesian coordinate system I; take the K curvature center of the eight-shaped groove between the Pth tile-shaped permanent magnet and the Qth tile-shaped permanent magnet as the origin, and the direction of the line connecting the origin to the midpoint of the arc projected by the eight-shaped groove on the cross-section Ω as the Y-axis direction, and establish a Cartesian coordinate system II in any direction perpendicular to the Y-axis as the X-axis direction; the Z-axis directions of the Cartesian coordinate system I and the Cartesian coordinate system II are both the central axis direction of the hub of the load rotating core;

[0018] After that, solve the basis transformation matrix from the Cartesian coordinate system II to the Cartesian coordinate system I:

[0019] (1)

[0020] It is stipulated that the Y-axis direction of the Pth tile-shaped permanent magnet and the Qth tile-shaped permanent magnet in the Cartesian coordinate system I is the magnetization direction; the eight-shaped permanent magnets sandwiched between the Pth tile-shaped permanent magnet and the Qth tile-shaped permanent magnet are the Uth eight-shaped permanent magnet and the Vth eight-shaped permanent magnet, and the Y-axis direction of the Uth eight-shaped permanent magnet and the Vth eight-shaped permanent magnet in the Cartesian coordinate system II is the magnetization direction;

[0021] The inner surface magnetic charge surface density of the Pth tile-shaped permanent magnet and the Qth tile-shaped permanent magnet:

[0022] (2)

[0023] (3)

[0024] The outer surface magnetic charge surface density of the Uth eight-shaped permanent magnet and the Vth eight-shaped permanent magnet:

[0025] (4)

[0026] (5)

[0027] Wherein, L is the distance between the origin of the Cartesian coordinate system Ⅰ and the origin of the Cartesian coordinate system Ⅱ, is the rotation angle of the Cartesian coordinate system Ⅱ relative to the Cartesian coordinate system Ⅰ about the central axis of the hub of the load rotation core, is the included angle between the line connecting the origin of the Cartesian coordinate system Ⅰ and the origin of the Cartesian coordinate system Ⅱ and the X-axis of the Cartesian coordinate system Ⅰ, is the unit vector in the XY plane of the Cartesian coordinate system Ⅰ, is the unit vector in the Y-axis direction of the Cartesian coordinate system Ⅰ, is the azimuth angle of the Cartesian coordinate system Ⅰ, is the unit vector in the XY plane of the Cartesian coordinate system Ⅱ, is the unit vector in the Y-axis direction of the Cartesian coordinate system Ⅱ; is the azimuth angle of the Cartesian coordinate system Ⅱ;

[0028] Step 3: Calculate the magnetic attraction torque of the Pth trapezoidal magnet and the Qth trapezoidal magnet on the included figure-eight permanent magnet;

[0029] It can be known from Step 1 that the base transformation matrix from the Cartesian coordinate system Ⅱ to the Cartesian coordinate system Ⅰ is ,

[0030] Then (6)

[0031] Wherein, and are the homogeneous coordinates of any point in the Cartesian coordinate system Ⅰ and the Cartesian coordinate system Ⅱ;

[0032] Calculate the magnetic attraction force of the Uth figure-eight permanent magnet and the Vth figure-eight permanent magnet sandwiched by the Pth trapezoidal magnet and the Qth trapezoidal magnet:

[0033] (7)

[0034] Wherein:

[0035] (8)

[0036] Wherein, is the relative position vector of any two magnetic charges on the surfaces of the selected trapezoidal magnet and the figure-eight permanent magnet, is the magnetic permeability of vacuum, are respectively the starting angle and the ending angle corresponding to the Pth trapezoidal magnet in the Cartesian coordinate system Ⅰ, are respectively the starting angle and the ending angle corresponding to the Qth trapezoidal magnet in the Cartesian coordinate system Ⅰ, are respectively the starting angle and the ending angle corresponding to the Uth figure-eight permanent magnet in the Cartesian coordinate system Ⅱ, They are respectively the starting angle and the ending angle corresponding to the Vth figure-eight permanent magnet in the Cartesian coordinate system Ⅱ.

[0037] After that, calculate the lever arm of the magnetic suction force:

[0038] Let be the lever arm of the magnetic suction force and the four-dimensional homogeneous vector of where = 1;

[0039] (9)

[0040] Thus, we get (10)

[0041] Furthermore, obtain the magnetic attraction torque:

[0042] (11)

[0043] Furthermore, obtain the total torque transmitted by a permanent magnet drive device with a figure-eight arrangement of magnets at a given slip angle between the inner and outer rotors:

[0044] (12)

[0045] where is the number of figure-eight permanent magnet slots, is the absolute value of the magnetic attraction torque to be obtained;

[0046] So far, the torque calculation of a permanent magnet drive device with a figure-eight arrangement of magnets is completed.

[0047] The beneficial effects of the present invention are as follows: A permanent magnet drive device with a figure-eight arrangement of magnets is proposed. Slots are opened inside the hub of the load rotating core, which reduces the eddy current distribution to a certain extent and significantly improves the torque transmission efficiency. At the same time, the dynamic adaptation of the system torque can be achieved by adjusting the slip angle between the inner and outer rotors, making it suitable for scenarios with variable loads. During operation, the high-elastic annular vibration isolation rubber airbag ring on the inner wall of the power-side sealing end cover plays an axial vibration isolation role, and the roller bearings on both sides enhance the system support and stability, greatly improving the system's ability to handle sudden working conditions. Meanwhile, the torque calculation method of the permanent magnet drive device with a figure-eight arrangement of magnets proposed by the present invention avoids the complicated calculation process of traditional finite element analysis, realizes the rapid and accurate solution of the transmitted torque, has good universality, can be used for the efficient analysis and solution of the torque of various permanent magnet drive devices, not only has a solid theoretical basis, but also shows high universality and practicality in engineering practice, providing an accurate and efficient algorithm tool for engineering design and optimization. Description of the Drawings

[0048] Figure 1It is a flow chart of the torque calculation method for a permanent magnet drive device with an eight-character arrangement of magnets;

[0049] Figure 2 It is a basic model of a permanent magnet drive device with an eight-character arrangement of magnets;

[0050] Figure 3 It is a radial sectional view and coordinate system of a permanent magnet drive device with an eight-character arrangement of magnets;

[0051] In the figure: 1 Load keyway shaft; 2 Load side vibration isolation roller bearing; 3 Load keyway shaft fastening bolt; 4 Rotor core seal housing fastening bolt; 5 High-elastic O-ring seal washer; 6 Tile-shaped permanent magnet; 7 Power rotating cylinder hub; 8 Power rotating cylinder dust-proof housing; 9 Power side seal end cover; 10 Seal end cover limit long bolt; 11 Power keyway shaft fastening bolt; 12 Power side vibration isolation roller bearing; 13 Power keyway shaft; 14 Rotor core seal cover plate limit bolt; 15 High-elastic annular vibration isolation rubber airbag ring; 16 High-elastic annular rubber airbag ring fastening bolt; 17 High-elastic annular vibration isolation rubber airbag ring fastening nut; 18 Rotor core limit seal cover; 19 Load rotor core hub; 20 Eight-character permanent magnet; 21 Load rotor core seal housing; N is the north pole of the tile-shaped permanent magnet; S is the south pole of the eight-character permanent magnet; is Cartesian coordinate system Ⅰ; is Cartesian coordinate system Ⅱ; K is the eight-character groove; P is the Pth tile-shaped permanent magnet; Q is the Qth tile-shaped permanent magnet; U is the Uth eight-character permanent magnet; V is the Vth eight-character permanent magnet; is the vector angle corresponding to the Pth and Qth tile-shaped permanent magnets in Cartesian coordinate system Ⅰ; is the vector angle corresponding to the Uth and Vth eight-character permanent magnets in Cartesian coordinate system Ⅱ; is the rotation angle of Cartesian coordinate system Ⅱ relative to Cartesian coordinate system Ⅰ around the central axis of the load rotor core hub. Specific implementation manner

[0052] The embodiments of the present invention will be further described below in conjunction with the drawings and technical solutions.

[0053] In this example, a permanent magnet drive device with an eight-character arrangement of magnets and four grooves opened inside the load rotor core hub is used, and the torque transmitted by the system at a given slip angle is calculated.

[0054] Among them, the journal diameter of the load keyway shaft 1 is 40 mm, the load side vibration isolation roller bearing 2 uses a cylindrical roller bearing with an inner diameter of 40 mm, the load keyway shaft fastening bolt 3 uses an internal hexagonal bolt, the rotor core seal housing fastening bolt 4 uses an internal hexagonal bolt, the high-elastic O-ring seal washer 5 uses a stainless steel grade A chamfered flat washer, and the inner surface curvature radius of the tile-shaped permanent magnet 6 is 74 mm, the central angle is 60°, the axial length is 60 mm, , the inner diameter of the power rotating cylinder hub 7 is 149 mm, the outer diameter is 180 mm, and the axial length is 60 mm. The thickness of the power rotating cylinder dust-proof shell 8 is 2 mm. The inner diameter of the power-side sealing end cover 9 is 144 mm, the outer diameter is 180 mm, and the axial length is 15 mm. The sealing end cover limit long bolt 10 uses an internal hexagon bolt. The power keyway shaft fastening bolt 11 uses an internal hexagon bolt. The power-side vibration isolation roller bearing 12 uses a cylindrical roller bearing with an inner diameter of 40 mm. The journal diameter of the power keyway shaft 13 is 40 mm. The rotating core sealing cover plate limit bolt 14 uses an internal hexagon bolt. The inner diameter of the high-elastic annular vibration isolation rubber airbag ring 15 is 70 mm, and the thickness is 5 mm. The high-elastic annular rubber airbag ring fastening bolt 16 uses an internal hexagon bolt. The high-elastic annular vibration isolation rubber airbag ring fastening nut 17 uses a nut. The thickness of the rotating core limit sealing cover 18 is 2 mm and the diameter is 120 mm. The diameter of the load rotating core hub 19 is 130 mm and the axial length is 60 mm. The curvature radius of the eight-shaped permanent magnet 20 is 60 mm, the central angle is 30°, and the axial length is 60 mm. , the thickness of the load rotating core sealing shell 21 is 2 mm. The distance L between the origin of coordinate system Ⅱ and Ⅰ is 100 mm, and the relative rotation angle = 150°. .

[0055] The installation steps of the permanent magnet rotating device with the magnets arranged in an eight-shaped pattern are as follows:

[0056] First, an eight-shaped groove is opened inside the load rotating core hub 19 and the eight-shaped permanent magnet 20 is embedded. The rotating core sealing shell 21 covers the outer surface of the load rotating core hub 19 to complete the assembly and fixation of the eight-shaped permanent magnet 20.

[0057] Second, the load keyway shaft 1 is fixed to the load rotating core hub 19 through the fastening bolt 3. The rotating core sealing shell fastening bolt 4 penetrates and fixes the load rotating core sealing shell 21 and the load rotating core hub 19. The rotating core limit sealing cover 18 is fixed to the power end of the load rotating core sealing shell 21 through the rotating core sealing cover plate limit bolt 14 to complete the assembly and sealing on the load side.

[0058] Third, a groove is opened on the inner wall of the power rotating cylinder hub 7 to embed the tile-shaped magnet 6. The power rotating cylinder dust-proof shell 8 is sleeved on the surface of the power rotating cylinder hub 7 to realize the assembly and fixation of the tile-shaped magnet 6. The sealing end cover limit long bolt 10 penetrates the power-side sealing end cover 9, the power rotating cylinder dust-proof shell 8, and the power rotating cylinder hub 7 and locks the three. The power keyway shaft 13 is fixed to the power-side sealing end cover 9 through the power keyway shaft fastening bolt 11 to realize the assembly and sealing on the power side.

[0059] Finally, the high-elastic annular vibration isolation rubber airbag ring 15 is locked in the inner cavity of the power-side sealing end cover 9 through the high-elastic annular rubber airbag ring fastening bolt 16 and the high-elastic annular vibration isolation rubber airbag ring fastening nut 17. The load-side vibration isolation roller bearing 2 and the power-side vibration isolation roller bearing 12 are respectively installed at the journal of the load keyway shaft 1 and the power keyway shaft 13. The high-elastic O-ring sealing washer 5 with a stainless steel grade A chamfered flat washer is placed under each of the above-mentioned bolts, completing the assembly of the system vibration isolation device and the sealing fasteners.

[0060] So far, the installation of a permanent magnet drive device with a magnet eight-shaped arrangement is completed.

[0061] A method for calculating the torque of a permanent magnet drive device with a magnet eight-shaped arrangement is as Figure 1 shown. The specific steps are as follows:

[0062] The first step is to solve the magnetic charge surface density of the tile-shaped magnet and the eight-shaped permanent magnet;

[0063] First, taking the intersection point of the central axes of the inner and outer rotors and the cross-section as the origin, establish the Cartesian coordinate system I, and establish the Cartesian coordinate system II with the center of curvature of the eight-shaped groove as the origin. Then, select the y-axis direction of the coordinate system where the tile-shaped magnet and the eight-shaped permanent magnet are located as the magnetization direction.

[0064] Calculated from equations (2), (3), (4), and (5) 、 。

[0065] The second step is to calculate the magnetic attraction torque of the two tile-shaped magnets on the clamped eight-shaped permanent magnet. From equation (1), it can be known that the transformation matrix , and the magnetic attraction torque of the two tile-shaped magnets on the clamped eight-shaped permanent magnet is obtained from equations (6), (7), (8), (9), (10), and (11) ;

[0066] The third step is to calculate the total magnetic attraction torque of the system. From equation (11), we get . So far, the calculation of the system torque of the permanent magnet drive device with a magnet eight-shaped arrangement at a given slip angle is completed.

[0067] This new type of permanent magnet drive device effectively reduces eddy current losses through the internal grooving design of the load rotating core hub, and realizes the adjustability of torque by adjusting the slip angle between the inner and outer rotors, thus flexibly adapting to the changing load scenarios. The design of the vibration isolation structure significantly weakens the impact of sudden working conditions on the system. The non-contact magnetic force drive significantly reduces the running wear and noise, further improving the stability and engineering reliability of the system.

[0068] Compared with traditional finite element analysis, this calculation method can achieve fast and accurate solution of the torque of the system at a given slip angle, avoiding the complicated calculation process of traditional finite element analysis and effectively reducing the time cost. This method also has high universality and is equally applicable to various other common permanent magnet drive devices, providing reliable theoretical support for the torque calculation of a variety of permanent magnet drive devices. It is a calculation method with strong engineering applicability.

Claims

1. A permanent magnet transmission device with magnets arranged in an eight-shaped pattern, characterized in that: The permanent magnet transmission device with magnets arranged in an eight-shaped pattern comprises a load keyway shaft (1), a load-side vibration isolation roller bearing (2), a tile-shaped magnetic steel (6), a power drum hub (7), a power drum dust cover (8), a power-side sealing end cover (9), a power-side vibration isolation roller bearing (12), a power keyway shaft (13), a high-elasticity annular vibration isolation rubber airbag ring (15), a core limit sealing cover (18), a load core hub (19), an eight-shaped permanent magnet (20) and a load core sealing shell (21); The load core hub (19) has an octave groove formed inside and an octave-shaped permanent magnet (20) embedded therein; the load core sealing shell (21) covers the outer surface of the load core hub (19), and the two are fixed; the core limiting sealing cover (18) is fixed to the power side of the load core sealing shell (21); the inner wall of the power drum hub (7) is grooved and a tile-shaped magnetic steel (6) is embedded therein; the power drum dust cover (8) is sleeved on the surface of the power drum hub (7); the power side sealing end cover (9) is fixed to the outer side of the power drum dust cover (8); The sealing end cover (9), the power drum dust cover (8) and the power drum hub (7) are fixedly connected; the high-elasticity annular vibration-isolating rubber airbag ring (15) is locked in the cavity inside the power side sealing end cover (9); the power keyway shaft (13) is fixed on the power side sealing end cover (9), and the load keyway shaft (1) is movably connected to the load core sealing shell (21); the load side vibration-isolating roller bearing (2) and the power side vibration-isolating roller bearing (12) are respectively mounted on the journals of the load keyway shaft (1) and the power keyway shaft (13).

2. The permanent magnet transmission device with magnets arranged in an eight-shaped pattern according to claim 1, characterized in that: All joints are equipped with high elastic O-rings (5).

3. A method for calculating torque of a permanent magnetic transmission device with a magnet figure eight arrangement as claimed in claim 1, characterized in that: Here are the steps: The first step is to determine the key parameters of the permanent magnet transmission device with magnets arranged in an eight-shaped pattern; Key parameters include residual magnetization of tile-shaped magnetic steel , residual magnetization intensity of figure eight permanent magnet , vacuum permeability , the radius of curvature of the tile-shaped magnetic steel 、Slot curvature radius , Equivalent magnetic charge density on the lower surface of the tile-shaped magnetic steel along the coordinate axis , the equivalent magnetic charge surface density of the outer surface of the figure eight permanent magnet , the axial length of the power drum hub , Axial length of the load core hub and the coordinate transformation matrix ; The second step is to calculate the magnetic charge surface density of the tile-shaped magnetic steel and the figure-eight permanent magnet; Taking the geometric center of the load core hub (19) as the origin, making a cross section Ω of the load core hub (19) through the origin, randomly selecting two adjacent tile-shaped magnetic steels (6), which are defined as the Pth tile-shaped magnetic steel (6) and the Qth tile-shaped magnetic steel (6); establishing a Cartesian coordinate system I with the directions of the lines connecting the origin and the midpoints of the arcs projected on the cross section Ω by the Pth tile-shaped magnetic steel (6) and the Qth tile-shaped magnetic steel (6) as the X-axis and Y-axis directions; establishing a Cartesian coordinate system II with the center of curvature K of the splayed groove sandwiched between the Pth tile-shaped magnetic steel (6) and the Qth tile-shaped magnetic steel (6) as the origin, the direction of the line connecting the origin and the midpoints of the arcs projected on the cross section Ω by the splayed groove as the Y-axis direction, and any direction perpendicular to the Y-axis as the X-axis direction; the Z-axis directions of the Cartesian coordinate systems I and II are both the directions of the central axis of the load core hub (19); After that, solve the basis transformation matrix from Cartesian coordinate system II to Cartesian coordinate system I: （1） It is specified that the Y-axis direction of the P-th tile-shaped magnetic steel (6) and the Q-th tile-shaped magnetic steel (6) in the Cartesian coordinate system I is the magnetization direction; the eight-shaped permanent magnets sandwiched by the P-th tile-shaped magnetic steel (6) and the Q-th tile-shaped magnetic steel (6) are the U-th eight-shaped permanent magnet and the V-th eight-shaped permanent magnet, and the Y-axis direction of the U-th eight-shaped permanent magnet and the V-th eight-shaped permanent magnet in the Cartesian coordinate system II is the magnetization direction; The inner surface magnetic charge density of the Pth tile-shaped magnetic steel (6) and the Qth tile-shaped magnetic steel (6): （2） （3） The outer surface magnetic charge density of the Uth figure eight permanent magnet and the Vth figure eight permanent magnet: （4） （5） Where L is the distance between the origin of Cartesian coordinate system I and the origin of Cartesian coordinate system II, is the rotation angle of Cartesian coordinate system II relative to Cartesian coordinate system I around the central axis of the load core hub (19), is the angle between the origin of Cartesian coordinate system I and the origin of Cartesian coordinate system II and the X-axis of Cartesian coordinate system I, is the unit vector in the XY plane in Cartesian coordinate system I, is the unit vector in the Y-axis direction in Cartesian coordinate system I, is the azimuth of Cartesian coordinate system I, is the unit vector in the XY plane in Cartesian coordinate system II, is the unit vector in the Y-axis direction in Cartesian coordinate system II; is the azimuth of Cartesian coordinate system II; Step 3: Calculate the magnetic attraction moment of the Pth tile-shaped magnetic steel (6) and the Qth tile-shaped magnetic steel (6) on the sandwiched figure-eight permanent magnet; From the first step, we can know the basis transformation matrix from Cartesian coordinate system II to Cartesian coordinate system I ,but （6） in, and are the homogeneous coordinates of any point in Cartesian coordinate system I and Cartesian coordinate system II; Calculate the magnetic attraction of the Uth eight-shaped permanent magnet and the Vth eight-shaped permanent magnet sandwiched by the Pth tile-shaped magnetic steel (6) and the Qth tile-shaped magnetic steel (6): （7） in: (8) in, is the relative position vector of any two magnetic charges on the surface of the tile-shaped magnetic steel (6) and the figure-eight permanent magnet, is the vacuum permeability, are the starting angle and ending angle of the Pth tile-shaped magnetic steel in Cartesian coordinate system I, respectively. are the starting angle and ending angle of the Qth tile-shaped magnetic steel in Cartesian coordinate system I, respectively. are the starting angle and ending angle of the Uth figure eight permanent magnet in Cartesian coordinate system II, are the starting angle and ending angle of the Vth figure eight permanent magnet in Cartesian coordinate system II respectively; After that, calculate the moment arm of the magnetic attraction: make Magnetic force arm The four-dimensional homogeneous vector ,in =1 （9） Thus, (10) Further obtain the magnetic attraction torque: （11） Furthermore, the total torque transmitted by a permanent magnet transmission device with magnets arranged in an eight-shaped pattern under a given inner and outer rotor slip angle is obtained: （12） in, is the number of eight-shaped permanent magnet slots, is the absolute value of the magnetic attraction torque required; At this point, the torque calculation of a permanent magnet transmission device with magnets arranged in an eight-shaped pattern is completed.

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