A fan-shaped permanent magnet assembly tool and its driving force prediction method

Abstract

The present invention belongs to the technical field of permanent magnet assembly, and discloses a fan-ring type permanent magnet assembly tool and a driving force prediction method thereof. The tool uses an ingenious mechanical structure to limit the anisotropic degrees of freedom of the permanent magnet, and adopts a ball screw transmission scheme and a servo drive mode to control the assembly accuracy of the permanent magnet. It can not only meet the assembly requirements of the inner / outer rotor permanent magnet of the permanent magnet coupling, but also can be applied to the assembly field of permanent magnets of different sizes and shapes by replacing the clamping plate A / B. It has the advantages of high precision and high efficiency, strong versatility, and good environmental compatibility. At the same time, the driving force prediction method proposed in the present invention is based on the theoretical basis of the permanent magnet equivalent magnetization current analytical model, and the magnetic attraction force between the permanent magnet to be assembled and the inner / outer rotor hub is clarified by solving the spatial magnetic induction intensity of the permanent magnet to be assembled. With the help of the permanent magnet assembly tool proposed in the present invention, the driving force required for assembly is predicted, and the calculation is simple and the prediction accuracy is high. It is a calculation method with engineering universality and convenience.

Description

Technical Field

[0001] The invention belongs to the technical field of permanent magnet assembly, and relates to a fan-ring type permanent magnet assembly tool and a driving force prediction method thereof. Background Art

[0002] Major technical equipment such as high-power wind turbines and underwater submersibles are vital to my country's energy security and national defense strength. Affected by the complex environment, the transmission system of this type of equipment serves in continuous operating conditions such as high load and strong vibration, and it is difficult to maintain good transmission performance for a long time. With the development of the third-generation permanent magnet materials, the permanent magnetic transmission technology relying on sintered NdFeB permanent magnets has been widely used in wind power, nuclear industry, aerospace, intelligent manufacturing and other fields due to its characteristics of no friction, strong environmental adaptability, and overload protection. As a typical representative of non-contact magnetic transmission technology, the permanent magnetic coupling realizes energy transfer from the input end to the output end by the interaction of N / S pole permanent magnets arranged alternately along the circumference of the inner and outer rotors, and has the advantages of buffering vibration reduction, compensation of small displacements and angles, etc. Its internal permanent magnet is magnetized radially, and its appearance is fan-shaped. After structural optimization, it is in the shape of an inverted trapezoid or a "convex" shape with a reserved dovetail groove. It is pressed against the inner wall of the hub by the boss on the hub surface to achieve mechanical limit. However, sintered NdFeB has a large magnetic energy and is brittle, which makes it very easy to attract and break with magnetic materials. In addition, the hub has a complex shape, and the mechanism of the joint action of the permanent magnets with alternating N / S poles is unclear. Manual assembly is difficult to ensure safety and is time-consuming and laborious. Therefore, the development of a fan-shaped permanent magnet assembly tool and its driving force prediction method can provide important theoretical support for the design and manufacture of permanent magnet couplings.

[0003] For the fan-ring type permanent magnet assembly tooling, Wei Minjian, Zhang Renzheng and others used a telescopic cylinder to drive the block to move radially in the patent "A permanent magnet motor rotor installation tooling" (CN 220291843 U), and then used the magnetic steel mounting seat and the block to complete the fan-ring type magnetic steel limiting and press it against the inner wall of the casing. However, the tooling does not take into account the suction effect between the magnetic steel and the rotor, lacks a magnetic steel protection structure, and cannot achieve axial positioning of the magnetic steel. It is only suitable for single-layer fan-ring type magnetic steel assembly occasions. Therefore, providing a universal and reliable permanent magnet assembly tooling is of great significance for the research of permanent magnet couplings. For the assembly driving force prediction method, Zhang Yuyang of Tianjin University proposed the interaction mechanism between rectangular, spherical and axially magnetized cylindrical permanent magnets commonly found in magnetic transmission structures in his doctoral dissertation "Research on Interaction between Permanent Magnets for Vibration Energy Harvesting Systems" in 2022, and completed the analytical modeling of spatial magnetic induction intensity by combining the equivalent magnetization current model, equivalent magnetic charge model and magnetic dipole model. However, no effective method has been proposed for radially magnetized fan-shaped permanent magnets, and the interaction mechanism between permanent magnets and other magnetic materials is unclear, and the driving force required for tooling and permanent magnet assembly is unknown. Therefore, it is very necessary to provide a method for predicting the driving force for fan-shaped permanent magnet assembly. Summary of the invention

[0004] In order to make up for the deficiencies of the prior art, the present invention invents a fan-ring type permanent magnet assembly tool and a driving force prediction method thereof. The purpose is to use a convenient and adjustable mechanical structure to limit the azimuthal degrees of freedom of the permanent magnet to be assembled, and to use a ball screw that can obtain high-precision, high-rigidity, high-speed and non-backlash micro-feed motion with a small driving torque as a transmission scheme, and to realize the linear motion of the permanent magnet to be assembled along the Z1 direction through positive transmission (from the screw rotation motion to the nut linear motion), and to realize the rotational motion of the hub by driving the hollow rotating table by a servo motor, and to further combine with simple operations to complete the permanent magnet assembly task; at the same time, based on the equivalent magnetization current analytical model, the magnetic attraction force between the permanent magnet and the hub is evaluated, and then the driving force / torque required for actual assembly is predicted, so as to avoid accidents such as cracking caused by the attraction between the permanent magnet and the magnetic material, solve the problems of difficult manual assembly operation and low installation efficiency, and improve the environmental safety factor, so as to provide important technical support for the high-precision and efficient assembly of permanent magnets and the prediction of driving force of permanent magnet couplings.

[0005] The technical solution of the present invention:

[0006] A fan-ring type permanent magnet assembly tool, comprising a hand wheel A1, a fixing block 2, a ball screw 3, a servo motor 4, a base 5, a support frame 6, an adapter plate 9, a hollow rotating table 10, a screw 11, a hand wheel B12, a guide rod A13, a linear bearing 14, a clamping plate A15, a baffle A16, a baffle B17, a connecting piece 18, a clamping plate B20, an angular contact ball bearing 21, a nylon anti-loosening nut 22, a guide rod B23, a screw nut 24 and a nut seat 25;

[0007] The base 5 is fixed on the ground, and the hollow turntable 10 is fixed on the upper surface of the base 5; the flange surface at one end of the adapter plate 9 is connected to the output interface of the hollow turntable 10, and the flange surface at the other end is connected to the flange interface reserved on the rotor hub; the servo motor 4 is connected to the input interface reserved on the hollow turntable 10; the ball screw 3 is vertically installed from the top through the rotor hub, the hollow turntable 10, and the base 5 in sequence, the end of the ball screw 3 is fixedly connected to the bottom surface of the base 5, and the head end is equipped with a fixed block 2, which is fixedly connected to the support frame 6, wherein the rotor hub is an inner rotor hub 7 or an outer rotor hub 8; the handwheel A1 is fixedly connected to the ball screw 3; the screw nut 24 moves along the raceway spirally on the ball screw 3, and the nut seat 25 is connected to The screw nut 24 is fixedly connected; the splint A15 is reserved with a light hole fixedly connected to the nut seat 25, the guide rod B23, the baffle A16, the baffle B17, and the linear bearing 14, and a threaded hole fixedly connected to the screw 11; the connecting piece 18 is fixedly connected to the baffle A16 and the baffle B17, and the splint B20 is reserved with a circular groove for placing the angular contact ball bearing 21 and a threaded hole connected to the guide rod B23. The angular contact ball bearing 21 is symmetrically installed in the circular grooves on the upper and lower end surfaces of the splint B20, and is locked by the shoulder on the screw 11 and the nylon anti-loosening nut 22. The head end of the screw 11 is fixedly connected to the handwheel B12; the guide rod A13 passes through the linear bearing 14 and the pin holes reserved in the base 5 in turn to limit the rotational freedom of the screw nut 24.

[0008] A method for predicting the driving force of the above-mentioned fan-shaped permanent magnet assembly tooling comprises the following steps:

[0009] The first step is to solve the spatial magnetic induction intensity generated by the permanent magnet;

[0010] The fan-shaped inner rotor permanent magnet 26 is taken as the research object, and the numerical solution is performed approximately as a regular shape; the fan-shaped inner rotor permanent magnet 26 is magnetized in the radial direction, and the magnetization current forms a closed loop along the outer surface, and the path of the closed loop is composed of two arcs and two straight lines; the fan ring is approximated as an isosceles trapezoid with an upper base of 2πr1θ / 360°, a lower base of 2πr2θ / 360°, and a height of r1-r2, r1 is the outer diameter of the fan ring, r2 is the inner diameter of the fan ring, and θ is the angle corresponding to the fan ring arc; and because The closed path grows linearly along the surface width, so the further cross section is approximated as a rectangle with a length of (r1+r2)πθ / 360° and a width of r1-r2. In order to facilitate coordinate transformation and symbolic representation, the geometric center of the rectangular permanent magnet with a length of a, a width of b, and a height of c is selected as the coordinate origin to establish a Cartesian coordinate system, in which the x-axis is along the height direction, the y-axis is along the length direction, and the z-axis is along the width direction. The length and width correspond to the length and width of the equivalent rectangular surface, respectively, and the magnetization direction coincides with the width direction.

[0011] According to the Biot-Savart law, the magnetic induction intensity of any point P (x, y, z) outside the magnetic field is expressed as:

[0012] (1)

[0013] Where R is the distance from the source point (x0, y0, z0) where the current element Idl is located to the field point P, e R is the unit vector pointing from the origin of the Cartesian coordinate system to the field point P, μ0 is the vacuum permeability, dl represents the unit current element, L is the current integration path, and I is the equivalent magnetizing surface current;

[0014] According to Ampere's loop law, assuming that the inner rotor permanent magnet 26 is uniformly and fully magnetized in a certain direction and reaches a saturated state, its internal magnetizing currents cancel each other out, and the magnetic induction intensity at any point in the external space is jointly affected by the magnetizing current along the surface through which it flows; for a rectangular permanent magnet, the equivalent magnetizing surface current is divided into the superposition of the front, rear, left and right surfaces, and then according to the right-hand screw rule, the equivalent magnetizing surface current expression is obtained:

[0015] (2)

[0016] Wherein, M is the magnetization intensity of the inner rotor permanent magnet 26, n is the outer normal unit vector of the surface of the inner rotor permanent magnet 26, dc is the tiny line element of the width of the current flowing through the surface, and c is the height of the inner rotor permanent magnet 26 along the magnetization direction;

[0017] Substituting equation (2) into equation (1) and rearranging it, the magnetic induction intensity of P is expressed as:

[0018] (3)

[0019] (4)

[0020] (5)

[0021] The total magnetic induction intensity value is expressed as:

[0022] (6)

[0023] The calculation formula of the magnetic induction intensity value of any point P is known, and the calibration points P are taken according to the assembly position of the inner rotor permanent magnet 26. i , calculate the magnetic induction intensity value B of each calibration point i ; When i is 1-5, P1, P2, P3, P4, and P5 correspond to the calibration points taken from the end face of the inner rotor hub 7 at intervals of 5 mm away from the end face; when i is 6-10, P6, P7, P8, P9, P 10 They respectively correspond to the calibration points taken on the contact surface between the inner rotor permanent magnet 26 and the inner wall of the inner rotor hub 7 after the inner rotor permanent magnet 26 enters the dovetail slot;

[0024] The second step is to solve the driving force required by the tooling;

[0025] It is known from the fan-ring permanent magnet assembly tooling that the rotational motion of the handwheel A1 will be converted into the linear motion of the linear bearing 14 along the guide rod A13 and the axial linear motion of the inner rotor permanent magnet 26; in the equilibrium state, there is no radial force between the linear bearing 14 and the guide rod A13, and the friction resistance caused is negligible; the ball screw and the screw nut are taken as the research objects, and the virtual displacement relationship is obtained by using the virtual work principle, that is, the handwheel A1 drives the ball screw to rotate one circle, and the screw nut will drive the inner rotor permanent magnet 26 to rise or fall one lead, as shown in formula (7):

[0026] (7)

[0027] Among them, δW F is the work done by the force applied to the object under study, δs is the microelement of the rising or falling distance of the inner rotor permanent magnet 26, δφ is the microelement of the rotation angle of the handwheel A1, T is the torque acting on the handwheel A1, η is the positive transmission efficiency of the ball screw 3, and Ph is the lead of the ball screw 3; F N is the total friction resistance, including the weight G of the screw 11, hand wheel B12, linear bearing 14, clamp A15, baffle A16, baffle B17, connecting piece 18, inner rotor permanent magnet 26, clamp B20, angular contact ball bearing 21, nylon lock nut 22, guide rod B23, nut seat 25 and the suction force between the inner rotor permanent magnet 26 and the inner rotor hub 7, expressed as:

[0028] (8)

[0029] In the actual assembly task, considering that the inner rotor permanent magnet 26 and the inner rotor hub 7 have irregular shapes and complex action mechanisms, a simplified formula is used for calculation, that is, the suction force F between the inner rotor hub 7 and the inner rotor permanent magnet 26 is expressed as:

[0030] (9)

[0031] Wherein, S1 represents the lower bottom surface area of ​​the inner rotor permanent magnet 26 when it enters the dovetail slot along the assembly direction, and S2 represents the contact area between the inner rotor permanent magnet 26 and the inner wall of the inner rotor hub 7 after entering the dovetail slot;

[0032] Substituting equations (8) and (9) into equation (7), we can obtain the required driving force T of the tooling at different positions: i :

[0033] (10)

[0034] Step 3: Solve the driving force required by the permanent magnet;

[0035] When the inner rotor permanent magnet 26 enters the dovetail groove and fits with the inner surface of the inner rotor hub 7, the axial suction force with the inner rotor hub 7 is greater than the static friction force with the inner surface of the inner rotor hub 7. The inner rotor permanent magnet 26 will quickly enter the inner rotor hub 7 until it is balanced with the static friction force and stays still at a certain position. After that, it needs to overcome the dynamic friction force and push it to the specified position. The driving force F required for the inner rotor permanent magnet 26 i It is expressed as:

[0036] (11)

[0037] Wherein, f is the dynamic friction factor between the inner rotor permanent magnet 26 and the inner rotor hub 7, the surface of the inner rotor permanent magnet 26 is plated with nickel copper nickel, and the surface of the inner rotor hub 7 is plated with blue white zinc, f=0.8;

[0038] Due to the nonlinear distribution of the spatial magnetic induction intensity generated by the inner rotor permanent magnet 26, a correction factor ε=1.1 is required to be introduced to the mean value of the magnetic attraction force at the measuring point. Make corrections, namely:

[0039] (12)

[0040] At this point, a driving force prediction method has been calculated.

[0041] The beneficial effect of the present invention is that a fan-shaped permanent magnet assembly tool is proposed, which uses an ingenious mechanical structure to limit the anisotropic degrees of freedom of the permanent magnet, and adopts a ball screw transmission scheme and a servo drive mode to control the permanent magnet assembly accuracy. It can not only meet the assembly requirements of the inner / outer rotor permanent magnets of the permanent magnet coupling, but also can be applied to the assembly field of permanent magnets of different sizes and shapes by replacing the clamping plates A / B. It has the advantages of high precision and efficiency, strong versatility, good environmental compatibility, etc.; at the same time, the driving force prediction method proposed in the present invention is based on the permanent magnet equivalent magnetization current analytical model as the theoretical basis, and the magnetic attraction force between the permanent magnet to be assembled and the inner / outer rotor hub is clarified by solving the spatial magnetic induction intensity of the permanent magnet to be assembled. The driving force required for assembly is predicted with the help of the permanent magnet assembly tool proposed in the present invention. The calculation is simple and the prediction accuracy is high, and it has strong practicality in engineering. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a flow chart of the driving force prediction method;

[0043] Figure 2 It is a schematic diagram of the structure of a fan-ring type permanent magnet assembly tooling;

[0044] Figure 3 It is a schematic diagram of the outer rotor permanent magnet assembly;

[0045] Figure 4 It is a schematic diagram of the inner rotor permanent magnet assembly;

[0046] Figure 5 It is a schematic diagram of the permanent magnet equivalent magnetizing current analysis model;

[0047] In the figure, 1-handwheel A, 2-fixed block, 3-ball screw, 4-servo motor, 5-base, 6-support frame, 7-inner rotor hub, 8-outer rotor hub, 9-adapter plate, 10-hollow rotary table, 11-screw, 12-handwheel B, 13-guide rod A, 14-linear bearing, 15-clamp A, 16-baffle A, 17-baffle B, 18-connecting plate, 19-outer rotor permanent magnet, 20-clamp B, 21-angular contact ball bearing, 22-nylon anti-loosening nut, 23-guide rod B, 24-screw nut, 25-nut seat, 26-inner rotor permanent magnet. DETAILED DESCRIPTION

[0048] The specific implementation manner of the present invention is further described below in conjunction with the accompanying drawings and technical solutions.

[0049] This embodiment uses an inner / outer rotor hub with 18 dovetail grooves evenly distributed along the circumference and a permanent magnet matched therewith, and uses the designed tooling and driving force prediction method to complete the permanent magnet assembly task and calculate the driving force required for assembly. Among them, the vacuum magnetic permeability μ0=4π×10 -7 H / m, the remanence of the permanent magnet Br = 1.41T, corresponding to the magnetization intensity M = 1.1×10 6 A / m, outer diameter r1=165mm, inner diameter r2=148mm, arc length corresponding angle θ=20°, approximated by a=55mm, b=54.6mm, c=17mm, surface nickel-plated copper-nickel, ball screw pitch Ph=5mm, positive transmission efficiency η=0.95, screw nut bears gravity G=25N, magnetic field action area of ​​permanent magnet and wheel hub before entering dovetail slot S1=928.69mm 2 , after entering the dovetail groove, the effective area S2 = 3167.77mm 2 .

[0050] The installation steps of a fan-shaped permanent magnet assembly tool are as follows:

[0051] First, the base 5 is fixed to the ground with anchor bolts, the hollow rotating table 10 is fixed to the base 5 with M10×50 cup head screws and φ8×40 internal thread cylindrical pins, the flange surface at one end of the adapter plate 9 is connected to the hollow rotating table 10 with M6×16 cup head screws and φ8×20 internal thread cylindrical pins, and the flange surface at the other end is fixed to the threaded hole reserved on the inner rotor hub 7 or the outer rotor hub 8 with M8×20 cup head screws; secondly, the servo motor 4 is connected to the threaded hole reserved on the hollow rotating table 10 with M6×16 cup head screws, the end of the ball screw 3 is fixed to the base 5, and the head end is fixed to the support frame 6 with M6×30 cup head screws, and then the handwheel A1 is fixed to the optical axis of the input end of the ball screw 3 with M5×10 set screws, the screw nut 24 cooperates with the ball screw 3, and is fixed with M5×16 cup head screws and nut seat 25 fixed connection; then the clamping plate A15 is connected to the linear bearing 14 with M4×12 cup head screws, connected to the guide rod B23 through the reserved φ8 pin hole, connected to the baffle A16 and the baffle B17 with M6×16 cup head screws, connected to the screw 11 through the reserved M10 threaded hole, connected to the nut seat 25 through the M5×16 cup head screw, and the connecting piece 18 is fixedly connected to the baffle A16 and the baffle B17 through the M6×12 cup head screw; finally, the clamping plate B20 is connected to the screw 11 through the angular contact ball bearing 21, and connected to the guide rod B23 through the M8 threaded hole. The end of the screw 11 is locked by a nylon anti-loosening nut 22, and the head end is fixedly connected to the handwheel B12 by an M5×10 set screw, and the base 5 is connected to the linear bearing 14 through the guide rod A13; at this point, the installation of a fan-ring type permanent magnet assembly tooling of the present invention is completed.

[0052] A fan-shaped permanent magnet assembly tool, firstly, the permanent magnet is placed between baffles A / B and is close to the baffle A which plays an assembly positioning role, the position of baffle B or a connecting piece is adjusted to clamp the permanent magnet and lock it with screws, so as to limit the freedom degree of the permanent magnet in the X1 and Y1 directions; secondly, the hand wheel B is rotated to make the clamping plate B close to the permanent magnet, so as to limit the freedom degree of the permanent magnet in the Z1 direction; then, the hand wheel A is rotated to convert the rotational motion of the ball screw into the linear motion of the clamping plate A along the Z1 direction, and at the same time, the servo motor is started to adjust the rotation angle of the hollow rotating table until the permanent magnet smoothly enters the dovetail groove reserved in the wheel hub; then, the hand wheel B is rotated in the opposite direction and the screws on the baffle B and the connecting piece are loosened to release the permanent magnet, the guide rod B is removed, the clamping plate B is rotated to the tangent direction of the permanent magnet arc surface, and the hand wheel A is rotated in the opposite direction to lift the clamping plate A; finally, a driving force along the Z1 direction is applied to the surface of the permanent magnet to make it reach the specified position, so as to complete the permanent magnet assembly. In addition, during the assembly process, in order to avoid scratches on the surface of the permanent magnet, a 1mm thick rubber strip is pasted on the baffle A / B and the clamp B in direct contact with the permanent magnet to achieve soft contact between the permanent magnet and the mechanical structure; the main function of the connecting piece is to limit the freedom of the permanent magnet along the X1 direction. When the permanent magnet is assembled for the first time, it can be appropriately adjusted according to the size of the permanent magnet and connected with screws but does not need to be tightened. After that, the baffle B and the clamp B can be directly adjusted to achieve rapid positioning of the permanent magnet; the permanent magnet is evenly distributed along the circumference of the hub, that is, each time a permanent magnet assembly task is completed, the hub needs to be rotated a certain angle to prepare for the next assembly task. Therefore, the number of pulse signals that the servo motor should obtain each time an assembly task is completed can be calculated and written into the control program as a fixed value to facilitate subsequent motor start and stop operations. The present invention can complete the assembly of permanent magnets on the inner / outer rotor using the same set of tooling components and simple operations, such as Figure 3 , 4 As shown, not only the assembly accuracy and efficiency are guaranteed, but also the assembly conditions of permanent magnets with the same shape and different sizes, or even different shapes and sizes, can be applied by simply replacing the clamping plates A / B. It has strong versatility and good environmental compatibility, and effectively avoids the cracking of permanent magnets. At the same time, the proposed driving force prediction method not only clarifies the distribution of magnetic induction intensity generated by the permanent magnet, but also provides a simple calculation method for the tooling and permanent magnet assembly driving force with high prediction accuracy. The results have theoretical guiding significance for actual assembly and have good practicality in engineering applications.

[0053] A flow chart of a driving force prediction method, such as Figure 1 As shown, the specific steps are as follows:

[0054] The first step is to calculate the spatial magnetic induction intensity generated by the permanent magnet;

[0055] First, starting from the hub surface, calculate points P1, P2, P3, P4, and P5 at intervals of 5 mm along the Z1 direction. The corresponding magnetic induction intensities B1 = 0.542T, B2 = 0.322T, B3 = 0.188T, B4 = 0.117T, and B5 = 0.077T are calculated by formula (6). Then, with the contact surface between the permanent magnet and the hub as the reference surface and O2 as the starting point, calculate points P6, P7, P8, P9, and P10 along the diagonal lines of X2 and Y2 at intervals of 7 mm. 10 , calculated by formula (6), the corresponding magnetic induction intensity is B6=0.336T, B7=0.356T, B8=0.396T, B9=0.463T, B 10 =0.574T.

[0056] Step 2: Calculate the driving force required for the tooling;

[0057] Then, S1 is substituted into formula (10) to obtain the required driving torque of the tooling at different assembly distances: T1 = 0.112 N·m, T2 = 0.053 N·m, T3 = 0.032 N·m, T4 = 0.025 N·m, and T5 = 0.023 N·m.

[0058] Step 3: Calculate the driving force required for the permanent magnet;

[0059] Finally, the calculation result of the first step and S2 are substituted into formula (11) to obtain the driving force required for permanent magnet assembly F6=113.97N, F7=128.08N, F8=157.96N, F9=215.88N, F 10 =331.64N, the average driving force required by the permanent magnet is obtained by formula (12): =200.34N.

[0060] This method characterizes the magnetic induction intensity of the spatial magnetic field by constructing an equivalent magnetizing current model, and obtains the magnetic attraction force between the permanent magnet and the hub under different assembly positions. At the same time, it comprehensively considers the permanent magnet assembly factors and accurately predicts the driving force required for the tooling and permanent magnet, providing a theoretical reference for actual assembly. It is also suitable for the assembly conditions of permanent magnets of commonly used shapes, and is simple to calculate. It is a calculation method with engineering universality and convenience.

Claims

1. A fan-shaped permanent magnet assembly tool, characterized in that: The fan-shaped permanent magnet assembly tool comprises a hand wheel A (1), a fixing block (2), a ball screw (3), a servo motor (4), a base (5), a support frame (6), an adapter plate (9), a hollow rotating table (10), a screw (11), a hand wheel B (12), a guide rod A (13), a linear bearing (14), a clamping plate A (15), a baffle A (16), a baffle B (17), a connecting piece (18), a clamping plate B (20), an angular contact ball bearing (21), a nylon anti-loosening nut (22), a guide rod B (23), a screw nut (24) and a nut seat (25); The base (5) is fixed on the ground, and the hollow rotating table (10) is fixed on the upper surface of the base (5); the flange surface at one end of the adapter plate (9) is connected to the output interface of the hollow rotating table (10), and the flange surface at the other end is connected to the flange interface reserved on the rotor hub; the servo motor (4) is connected to the input interface reserved on the hollow rotating table (10); the ball screw (3) passes through the rotor hub, the hollow rotating table (10), and the base (5) from the top and is vertically installed, the end of the ball screw (3) is fixedly connected to the bottom surface of the base (5), and the head end is equipped with a fixing block (2) fixedly connected to the support frame (6), wherein the rotor hub is an inner rotor hub (7) or an outer rotor hub (8); the hand wheel A (1) is fixedly connected to the ball screw (3); the screw nut (24) moves along the raceway on the ball screw (3) in a spiral motion, and the nut seat (25) is connected to the screw nut The nut (24) is fixedly connected; the clamping plate A (15) is reserved with a light hole fixedly connected to the nut seat (25), the guide rod B (23), the baffle A (16), the baffle B (17), and the linear bearing (14), and a threaded hole fixedly connected to the screw (11); the connecting piece (18) is fixedly connected to the baffle A (16) and the baffle B (17); the clamping plate B (20) is reserved with a circular groove for placing the angular contact ball bearing (21) and a threaded hole connected to the guide rod B (23); the angular contact ball bearing (21) is symmetrically installed in the circular grooves on the upper and lower end surfaces of the clamping plate B (20), and is locked by the shaft shoulder on the screw (11) and the nylon anti-loosening nut (22); the head end of the screw (11) is fixedly connected to the handwheel B (12); the guide rod A (13) passes through the pin holes reserved in the linear bearing (14) and the base (5) in turn to limit the rotational freedom of the screw nut (24).

2. A method for predicting driving force of the fan-ring type permanent magnet assembly tool according to claim 1, characterized in that: Here are the steps: The first step is to solve the spatial magnetic induction intensity generated by the permanent magnet; The fan-shaped inner rotor permanent magnet (26) is taken as the research object, and its cross section is approximated as a rectangle with a length of (r1+r2)πθ / 360° and a width of r1-r2 for numerical solution; wherein r1 is the outer diameter of the fan-shaped ring, r2 is the inner diameter of the fan-shaped ring, and θ is the angle corresponding to the arc of the fan-shaped ring; in order to facilitate coordinate transformation and symbolic representation, the geometric center of the rectangular permanent magnet with a length of a, a width of b, and a height of c is selected as the coordinate origin to establish a Cartesian coordinate system, wherein the x-axis is along the height direction, the y-axis is along the length direction, and the z-axis is along the width direction, the length and the width correspond to the length and the width of the equivalent rectangular surface, respectively, and the magnetization direction coincides with the width direction; According to the Biot-Savart law, the magnetic induction intensity of any point P (x, y, z) outside the magnetic field is expressed as: (1) Where R is the distance from the source point (x0, y0, z0) where the current element Idl is located to point P, e R is the unit vector pointing from the origin of the Cartesian coordinate system to point P, μ0 is the vacuum permeability, dl represents the unit current element, L is the current integration path, and I is the equivalent magnetizing surface current; According to Ampere's circuit law, assuming that the inner rotor permanent magnet (26) is uniformly and fully magnetized in a certain direction and reaches a saturated state, its internal magnetizing currents cancel each other out, and the magnetic induction intensity at any point in the external space is jointly exerted by the magnetizing current along the surface through which it flows; for a rectangular permanent magnet, the equivalent magnetizing surface current is divided into the superposition of the front, rear, left and right surfaces, and then according to the right-hand screw rule, the equivalent magnetizing surface current expression is obtained: (2) Wherein, M is the magnetization intensity of the inner rotor permanent magnet (26), n is the outer normal unit vector of the surface of the inner rotor permanent magnet (26), dc is the tiny line element of the width of the current flowing through the surface, and c is the height of the inner rotor permanent magnet (26) along the magnetization direction; Substituting equation (2) into equation (1) and rearranging it, we can obtain the magnetic induction intensity B of P: x , B y , B z ; The total magnetic induction intensity value is expressed as: (6) The calculation formula of the magnetic induction intensity value of any point P is known, and the calibration point P is taken according to the assembly position of the inner rotor permanent magnet (26). i , calculate the magnetic induction intensity value B of each calibration point i When i is 1 to 5, P1, P2, P3, P4, and P5 correspond to the calibration points taken from the end face of the inner rotor hub (7) at intervals of 5 mm in the direction away from the end face; when i is 6 to 10, P6, P7, P8, P9, and P10 correspond to the calibration points taken from the end face of the inner rotor hub (7) at intervals of 5 mm in the direction away from the end face. 10 They respectively correspond to the calibration points taken on the contact surface between the inner rotor permanent magnet (26) and the inner wall of the inner rotor hub (7) after the inner rotor permanent magnet (26) enters the dovetail groove; The second step is to solve the driving force required by the tooling; It is known from the fan-ring type permanent magnet assembly tooling that the rotational motion of the hand wheel A (1) will be converted into the linear motion of the linear bearing (14) along the guide rod A (13) and the axial linear motion of the inner rotor permanent magnet (26); in the equilibrium state, there is no radial force between the linear bearing (14) and the guide rod A (13), and the friction resistance caused is negligible; the ball screw and the screw nut are taken as the research objects, and the virtual displacement relationship is obtained by using the principle of virtual work, that is, when the hand wheel A (1) drives the ball screw to rotate one circle, the screw nut will drive the inner rotor permanent magnet (26) to rise or fall one lead, as shown in formula (7): (7) Among them, δW F is the work done by the force applied to the object under study, δs is the microelement of the rising or falling distance of the inner rotor permanent magnet (26), δφ is the microelement of the rotation angle of the handwheel A1, T is the torque acting on the handwheel A1, η is the positive transmission efficiency of the ball screw (3), and Ph is the lead of the ball screw (3); F N is the total friction resistance, including the weight G of the screw (11), hand wheel B (12), linear bearing (14), clamping plate A (15), baffle A (16), baffle B (17), connecting plate (18), inner rotor permanent magnet (26), clamping plate B (20), angular contact ball bearing (21), nylon lock nut (22), guide rod B (23), nut seat (25) and the suction force between the inner rotor permanent magnet (26) and the inner rotor hub (7), expressed as: (8) In the actual assembly task, considering that the inner rotor permanent magnet (26) and the inner rotor hub (7) have irregular shapes and a complex mechanism of action, a simplified formula is used for calculation, that is, the suction force F between the inner rotor hub (7) and the inner rotor permanent magnet (26) is expressed as: (9) Wherein, S1 represents the bottom surface area of ​​the inner rotor permanent magnet (26) when it enters the dovetail slot along the assembly direction, and S2 represents the contact area between the inner rotor permanent magnet (26) and the inner wall of the inner rotor hub (7) after entering the dovetail slot; Substituting equations (8) and (9) into equation (7), we can obtain the required driving force T of the tooling at different positions: i : (10) Step 3: Solve the driving force required by the permanent magnet; When the inner rotor permanent magnet (26) enters the dovetail groove and fits with the inner surface of the inner rotor hub (7), the axial suction force with the inner rotor hub (7) is greater than the static friction force with the inner surface of the inner rotor hub (7), and the inner rotor permanent magnet (26) will quickly enter the inner rotor hub (7) until it is balanced with the static friction force and stays still at a certain position; then it needs to overcome the dynamic friction force and push it to the specified position; the driving force F required for the inner rotor permanent magnet (26) is i It is expressed as: (11) Wherein, f is the dynamic friction factor between the inner rotor permanent magnet (26) and the inner rotor hub (7), the surface of the inner rotor permanent magnet (26) is plated with nickel copper nickel, and the surface of the inner rotor hub (7) is plated with blue white zinc; Due to the nonlinear distribution of the spatial magnetic induction intensity generated by the inner rotor permanent magnet (26), a correction factor ε=1.1 is required to be introduced to the mean value of the magnetic attraction force at the measuring point. Make corrections, namely: (12) At this point, a driving force prediction method has been calculated.

3. The driving force prediction method of the fan-ring type permanent magnet assembly tool according to claim 2 is characterized in that: Substituting equation (2) into equation (1) and rearranging it, we can obtain the magnetic induction intensity B of P: x , B y , B z As shown below: (3) (4) (5)。 4. The driving force prediction method of the fan-ring type permanent magnet assembly tool according to claim 2 is characterized in that: f=0.8。

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