A synchronous hunting electro-permanent magnetic composite thrust bearing and a quasi-zero stiffness design method in any interval thereof

Abstract

The application belongs to the technical field of hybrid magnetic bearing, and discloses a synchronous shifting electro-permanent magnetic composite thrust bearing and a quasi-zero stiffness design method in any interval of the synchronous shifting electro-permanent magnetic composite thrust bearing. The synchronous shifting electro-permanent magnetic composite thrust bearing is proposed, and the follow-up regulation and control of the air gap thickness between the electromagnetic bearing coil and the thrust disc can be realized through closed-loop control, so that the problem of the mismatch between the rotor shifting amount allowed by the permanent magnetic bearing and the rotor shifting amount allowed by the electromagnetic bearing is solved, and the synchronous shifting electro-permanent magnetic composite thrust bearing has technical advantages of low operation power consumption, complete suspension in the bearing direction, low risk of fatigue failure and wear of parts in actual application. Further, a quasi-zero stiffness design method in any interval of the synchronous shifting electro-permanent magnetic composite thrust bearing is proposed, and two control modes based on current control and air gap control are given, so that the quasi-zero stiffness design in any interval can be realized, thereby improving the longitudinal vibration reduction and isolation performance. The method is simple to operate and has high control precision in actual application.

Description

Technical Field

[0001] This invention belongs to the field of hybrid magnetic bearing technology, and relates to a synchronous kinetic electric-permanent magnet composite thrust bearing and its quasi-zero stiffness design method in arbitrary intervals. Background Technology

[0002] Longitudinal vibration control of underwater equipment propulsion shafting is a key technology for improving its acoustic stealth performance and the accuracy of detection equipment. Traditional contact-type oil-lubricated thrust bearings are often designed with high support stiffness to withstand higher loads, but this increased stiffness weakens the bearing's ability to isolate external disturbances. Quasi-zero stiffness technology, due to its excellent low-frequency vibration isolation performance, is considered an effective means to solve the problem of longitudinal low-frequency vibration in propulsion shafting. However, applying quasi-zero stiffness technology to the longitudinal support of underwater propulsion shafting faces several severe challenges, including fundamental limitations and poor adaptability to dynamic operating conditions. To achieve the goal of quasi-zero stiffness design of the propulsion shaft system, Weng Zeyu, Yu Xingxing, Hu Jingjing, and others proposed a quasi-zero stiffness vibration isolation device for submarine propulsion shaft system with the combined action of positive and negative stiffness mechanisms in the patent "A semi-active control quasi-zero stiffness vibration isolation device and method for submarine propulsion shaft system" (CN202211029332.3). This device can effectively reduce the natural frequency of the system and thus improve the vibration reduction and isolation effect. However, the positive and negative stiffness mechanisms in the paper have many components and complex interaction relationships. They also use dampers, springs, gears, and racks, which inevitably pose risks such as wear, fatigue, and failure. It is also difficult for the system to achieve closed-loop active control.

[0003] To address the issues of fatigue, high wear, and high support stiffness in actual ship applications of conventional vibration isolation components, magnetic bearings, with their "wear-free load-bearing" and "flexible support" characteristics, have become a feasible solution. However, permanent magnet bearings, through magnetic circuit design, can only achieve a predetermined load-bearing target and are difficult to achieve adaptive stiffness adjustment and near-zero stiffness design. In contrast, electromagnetic bearings can achieve a certain range of dynamically controllable electromagnetic force output by controlling the coil current, thus achieving dynamic stiffness adjustment. However, their load-bearing capacity and power consumption are important factors restricting their application in underwater equipment. To overcome the limitations of single permanent magnet or electromagnetically driven magnetic bearings, composite thrust bearing solutions have become an effective approach. In their patent "An Electromagnetic-Static Dual Suspension Thrust Bearing" (CN201710266659.5), Zhao Jianhua, Du Dongyuan, Wang Qiang, and others proposed a composite thrust bearing solution combining hydrostatic support and electromagnetic suspension support systems to remove the design limitations of the oil return groove, improve the bearing's load-bearing capacity and stiffness, and enhance the adjustment capability and precision of the bearing system. However, the composite thrust bearing solution proposed in this paper only aims for high load-bearing capacity and high stiffness, and cannot achieve a longitudinal quasi-zero stiffness design. Furthermore, the electromagnetic-static composite thrust bearing solution is still essentially a contact bearing, and the wear problem of key load-bearing components still exists. Although the electro-permanent magnet composite thrust bearing scheme has many technical advantages, the electromagnetic bearing is very sensitive to changes in the air gap between the control coil and the thrust plate. In order not to affect the load-bearing performance of the electromagnetic bearing, the rotor movement usually needs to be limited to a very small range, much smaller than the rotor movement allowed by the permanent magnet bearing. Therefore, how to effectively solve the problem of asynchronous movement between the permanent magnet bearing rotor and the electromagnetic bearing thrust plate is the key to solving whether the two can be effectively combined.

[0004] This paper addresses the effective composite problem of electro-permanent magnet composite thrust bearings, proposing a scheme for electro-permanent magnet composite thrust bearings with closed-loop synchronous control of axial movement. Based on this, an analytical method is proposed to achieve quasi-zero stiffness design in any displacement range of the bearing. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, this invention provides a synchronously undulating electro-permanent magnet composite thrust bearing. Its purpose is to use a built-in displacement sensor to feed the rotor position information back to the control system in real time. The control system dynamically adjusts the longitudinal position of the electromagnetic bearing coil via hollow hydraulic cylinders installed at both ends of the bearing to compensate for the rotor's undulation in real time, ensuring that the air gap between the electromagnetic bearing coil and the thrust plate remains at a set value, thereby achieving the goal of "synchronous undulation." Furthermore, to improve the longitudinal vibration reduction and isolation performance of the bearing, a quasi-zero stiffness design method for the synchronously undulating electro-permanent magnet composite thrust bearing in any range is proposed. The principle of this method is as follows: first, the force-displacement characteristics of the permanent magnet bearing are obtained through calibration; then, by adjusting the control current of the electromagnetic bearing coil or the air gap thickness parameter, the output force of the electromagnetic bearing in a certain displacement range is set point by point, compensating for or weakening the force generated by the permanent magnet bearing on the rotor in that range, so that the resultant force on the rotor remains essentially unchanged when it undulates in that range, thereby achieving a quasi-zero stiffness design.

[0006] For a given displacement range, the permanent magnet bearing force displacement calibration and electromagnetic bearing current parameter setting only need to be performed once, and the synchronous axial movement process adopts closed-loop control, which has technical advantages such as simple operation and high control accuracy in practical applications. In addition, the output of the electromagnetic bearing only plays an auxiliary role in the entire control process, and the main load is still borne by the permanent magnet bearing. The actual operating power consumption is low, and the bearing direction is completely suspended, resulting in a low risk of fatigue failure and wear of components.

[0007] The technical solution of the present invention: A synchronous kinetic electric-permanent magnet composite thrust bearing includes an output flange 1, an inner rotor back iron 2, a bearing cover 3, a support bearing 4, a distance sensor 5, a floating base 6, a positive-acting coil 7, a yoke thrust disk 8, an inner ring permanent magnet 9, an outer stator base 10, an outer ring permanent magnet 11, a hollow electric cylinder housing 12, an annular piston head 13, and a reaction coil 14. The inner ring permanent magnet 9 and the outer ring permanent magnet 11 are respectively magnetically attracted and installed on the smooth mounting surfaces of the inner rotor back iron 2 and the outer stator base 10; the yoke thrust disk 8 is interference-fitted with the shoulders at both ends of the inner rotor back iron 2, and the output flange 1 is fixed to the end of the inner rotor back iron 2 for connection with other parts of the shaft system; the hollow electric cylinder housing 12, the annular piston head 13, and the floating base 6 together form a synchronous axial actuator, and the floating base 6 is fixed on the output plane of the annular piston head 13; the support bearing 4, the distance sensor 5, and the positive action coil 7 near the left side of the bearing are embedded in the floating base 6, together forming a positive action floating unit, and the electromagnetic force generated by the positive action coil 7 is opposite to the direction of the external force to increase the resultant force; the support bearing 4 and the distance sensor 5 near the right side of the bearing are... The reaction coil 14 is also embedded in the floating base 6, forming a reaction floating unit. The electromagnetic force generated by the reaction coil 14 is in the same direction as the external force, which is used to reduce the resultant force. The support bearing 4 is used to provide radial support and maintain stability in the non-load-bearing direction. It is fixed to the side of the floating base 6 by the bearing cover 3. The distance sensor 5 is used to measure the air gap thickness between the positive action coil 7, the reaction coil 14 and the yoke thrust plate 8, and provide real-time feedback. The annular piston head 13 is driven by the hydraulic oil in the cylinder to achieve reciprocating motion and can reach any set position by controlling the flow and pressure. The hollow electric cylinder housing 12 is fixed to both ends of the outer stator base 10 through the stop, so as to achieve longitudinal fixation of the outer ring permanent magnet 11 and effectively transmit the reaction force to the outer stator base 10.

[0008] A method for designing quasi-zero stiffness in arbitrary intervals of a synchronous kinetic electric-permanent magnet composite thrust bearing, comprising the following steps: The first step is to determine the parameters of the electro-permanent magnet composite thrust bearing; Structural parameters: The inner radius of the outer permanent magnet 11 is... r 1. The outer radius of the inner permanent magnet 9 is r 2. The inner radius of the yoke thrust disk 8 is r 3. The thicknesses of the inner permanent magnet 9 and the outer permanent magnet 11 are: h 1 and the number of layers is n The thickness of the yoke thrust disc 8 is h 2. The widths of the inner permanent magnet 9 and the outer permanent magnet 11 are: l The preset value for the air gap thickness between the positive-acting coil 7 and the yoke thrust plate 8 is... δ 10 The preset value for the air gap thickness between the reaction coil 14 and the yoke thrust plate 8 is... δ 20 The number of turns of the positive-acting coil 7 is N 1. The number of turns of the reaction coil 14 is N 2. The preset current value of the positive-acting coil 7 is Ip0 The preset current value of the reaction coil 14 is I n0 Material parameters: The residual magnetic flux density of the inner permanent magnet 9 and the outer permanent magnet 11 is... B r ; the oscillation interval with quasi-zero stiffness in any interval [ m , n ], m The lower limit of the interval n The upper limit of the interval; The second step is to obtain the calibrated bearing capacity through experiments and to obtain the expression through polynomial fitting. The calibrated load capacity of the electro-permanent magnet composite thrust bearing was obtained through experiments when only the inner ring permanent magnet 9 and the outer ring permanent magnet 11 interacted. The calibrated load capacity fitting expression for the entire axial movement range was obtained through polynomial fitting. F b ( z )as follows: In the formula, z This refers to the longitudinal displacement. k 1. k 2. k 3 and k 4 represents the polynomial fitting coefficients; The third step is to calculate the average resultant force in the selected interval and then calculate the corresponding displacement. Due to the fitting expression F b ( z The nonlinear monotonically increasing trend occurs throughout the entire fluctuation interval; therefore, any selected fluctuation interval [ m There exists a unique variable [n]. z 0 and the fluctuation range [ m [n] average resultant force F avg Correspondingly, the resultant force F avg and lateral movement z The parsing expression for 0 is as follows: In the formula, F b ( m The longitudinal displacement is m The rated bearing capacity at that time F b ( n The longitudinal displacement is n The rated bearing capacity at that time p andq To simplify the coefficients, they are calculated using the following formula: ω The cubic root of unity is 1, and it is calculated using the following formula; In the formula, i It is the imaginary unit, and i 2 =-1; Step 4: Set the control mode for the positive-acting coil 7 of the positive-acting floating unit; To control the electromagnetic attraction force generated by the positive-acting coil 7 on the yoke thrust plate 8, two control modes are provided: current control mode and air gap control mode. Assuming that the magnetomotive force generated by the positive-acting coil 7 falls entirely on the air gap between the positive-acting coil 7 and the yoke thrust plate 8, based on force balance, the output force of the positive-acting coil 7... F ep It is calculated by the following formula: In the formula, z 1 represents the displacement range variable during which the positive-acting coil 7 is in operation, and ; F b ( z 1 The longitudinal displacement is z 1 The rated bearing capacity at that time; μ 0 is the permeability of free space, and μ 0 = 4π × 10 -7 H / m; A For effective working cross-sectional area; I p ( z 1) The longitudinal displacement of the control current of the positive-acting coil 7 z The change in 1 does not change the air gap thickness between the positive-acting coil 7 and the yoke thrust plate 8 in the current control mode. δ 1( z 1) The amount of longitudinal movement of the air gap thickness between the positive-acting coil 7 and the yoke thrust plate 8. z The change in 1 does not change the control current of the positive-acting coil 7 in the air gap control mode; A , I p ( z 1) and δ 1( z 1) Calculated using the following formula: ; Step 5: Set the control mode for the reaction coil 14 of the reaction floating unit; Similar to step four, based on the force balance, the output force of reaction coil 14... F en It is calculated by the following formula: In the formula, z 2 represents the displacement range variable during which the reaction coil 14 is in operation, and ; F b ( z 2) The longitudinal displacement is z The rated bearing capacity at time 2; I n ( z 2) The amount of longitudinal displacement of the control current of the reaction coil 14 z The change in 2, under current control mode, is calculated by the following formula: δ 2( z 2) The amount of longitudinal movement of the air gap thickness between the reaction coil 14 and the yoke thrust plate 8. z The change of 2, in the air gap control mode, is calculated by the following formula: ; Step 6: Obtain the load-bearing capacity expression for the electro-permanent magnet composite thrust bearing, including the quasi-zero stiffness range; In summary, the bearing capacity of the electro-permanent magnet composite thrust bearing within the entire axial displacement range, including the quasi-zero stiffness range, is... F ( z It can be expressed by the following formula: From the above formula, it can be seen that within any set displacement range [ m , n The load-bearing capacity of the electro-permanent magnet composite thrust bearing is constant. F avg Thus, the design of quasi-zero stiffness in any range of the electro-permanent magnet composite thrust bearing is completed.

[0009] The beneficial effects of this invention are as follows: It proposes a synchronously moving electro-permanent magnet composite thrust bearing, which can realize the follow-up adjustment of the air gap thickness between the electromagnetic bearing coil and the thrust disk through closed-loop control, solving the problem of mismatch between the allowable rotor movement of the permanent magnet bearing and the allowable rotor movement of the electromagnetic bearing. In practical applications, it has technical advantages such as low power consumption, complete suspension in the load direction, low component fatigue failure, and low wear risk. Furthermore, it proposes a quasi-zero stiffness design method for the synchronously moving electro-permanent magnet composite thrust bearing in any range, and provides two control modes based on current control and air gap control, which can realize the quasi-zero stiffness design in any range, thereby improving the vibration reduction and isolation performance in that range. This design method is simple to operate and has high control accuracy in practical applications. Attached Figure Description

[0010] Figure 1 This is an assembly drawing of a synchronous kinetic electric-permanent magnet composite thrust bearing; Figure 2 yes Figure 1 Sectional view in; Figure 3 It is a test result of force-displacement characteristics and polynomial fitting curve under the action of only permanent magnet bearings; Figure 4 The design results are for a current control mode with quasi-zero stiffness in an arbitrary range. Figure 5 The design results are for an air gap control mode with quasi-zero stiffness in an arbitrary range. Figure 6 Here is a flowchart of a design method for quasi-zero stiffness in arbitrary intervals; In the diagram: 1-Output flange, 2-Inner rotor back iron, 3-Bearing cover, 4-Support bearing, 5-Distance sensor, 6-Floating base, 7-Direct action coil, 8-Yoke thrust plate, 9-Inner ring permanent magnet, 10-Outer stator base, 11-Outer ring permanent magnet, 12-Hollow electric cylinder housing, 13-Annular piston head, 14-Reverse action coil. Detailed Implementation

[0011] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and technical solutions.

[0012] This implementation case uses an electro-permanent magnet composite thrust bearing with a maximum thrust of 12.3 kN and a maximum axial movement of 12 mm (see...). Figure 1 To perform quasi-zero stiffness design in any interval, the specific process is as follows: Figure 6 As shown, the steps are as follows: The first step is to determine the parameters of the electro-permanent magnet composite thrust bearing; Parameters of electro-permanent magnet composite thrust bearing are as follows Figure 2 As shown, the inner radius of the outer ring permanent magnet 11 r1=0.08m, outer radius of inner permanent magnet 9 r 2 = 0.075m, inner radius of the yoke thrust disk 8 r 3=0.05m, thickness of inner permanent magnet 9 and outer permanent magnet 11 h 1 = 0.015m, number of floors n =4. Thickness of the yoke thrust plate 8 h 2 = 0.025m, width of inner permanent magnet 9 and outer permanent magnet 11 l =0.025m, preset value of air gap thickness between the positive-acting coil 7 and the yoke thrust disk 8 δ 10 =0.0004m, preset value of air gap thickness between reaction coil 14 and yoke thrust disk 8 δ 20 =0.0008m, the number of turns of the positive-acting coil 7 is N 1=150, the number of turns of the reaction coil 14 is N 2=200, preset current value of positive acting coil 7 I p0 =1.5A, preset current value of reaction coil 14 I n0 =1A, Residual magnetic flux density of inner permanent magnet 9 and outer permanent magnet 11 B r =1.41T, lower limit of displacement range m =6mm, upper limit of displacement range n =8mm; The second step is to obtain the calibrated bearing capacity through experiments and to obtain the expression through polynomial fitting. like Figure 3 The calibrated load capacity of the electro-permanent magnet composite thrust bearing was obtained through experiments when only the inner ring permanent magnet 9 and the outer ring permanent magnet 11 interacted. The calibrated load capacity fitting expression for the entire axial movement range was obtained through polynomial fitting. F b ( z )as follows: Among them, the polynomial fitting coefficients k 1 = 0.1114 k 2 = -80.3198 k 3 = 1976.1133 k 4 = -47.3583; The third step is to calculate the average resultant force in the selected interval and then calculate the corresponding displacement. For the selected oscillation range [6,8] mm, the calculation yields... F b(6) = 8941.9 N F b (8) = 10678.1 N p =-1.5568×10 5 , q =-2.3621×10 7 , F avg =9810.0N、 z 0 = 6.9 mm; Step 4: Set the control mode for the positive-acting coil 7 of the positive-acting floating unit; Calculation obtained A =9.8174×10 -3 m 2 The current control mode expression for the positive-acting coil 7 is as follows: The expression for the air gap control mode of the positive-acting coil 7 is as follows: In the formula, z 1∈[6, 6.9) mm; Step 5: Set the control mode for the reaction coil 14 of the reaction floating unit; The current control mode expression for the reaction coil 14 is as follows: The expression for the air gap control mode of the reaction coil 14 is as follows: In the formula, z 2∈(6.9, 8] mm; Step 6: Obtain the load-bearing capacity expression for the electro-permanent magnet composite thrust bearing, including the quasi-zero stiffness range; The design results of the current control mode with a selected oscillation range of [6, 8] mm and quasi-zero stiffness are as follows: Figure 4 As shown, the design results of the air gap control mode are as follows: Figure 5 As shown, the bearing capacity of the electro-permanent magnet composite thrust bearing within the entire range of motion is... F ( z The expression for ) is as follows: This completes the design of quasi-zero stiffness in any range for the electro-permanent magnet composite thrust bearing.

[0013] This method achieves synchronous oscillation through closed-loop control and provides two control modes based on current control and air gap control. It can realize quasi-zero stiffness design in any range, thereby improving the vibration reduction and isolation performance of that range. The design method is simple to operate and has high control accuracy in practical applications.

Claims

1. A method for designing quasi-zero stiffness in arbitrary intervals of a synchronous kinetic electric-permanent magnet composite thrust bearing, characterized in that, The steps are as follows: The first step is to determine the parameters of the electro-permanent magnet composite thrust bearing; Structural parameters: The inner radius of the outer permanent magnet (11) is r 1. The outer radius of the inner permanent magnet (9) is r 2. The inner radius of the yoke thrust disk (8) is r 3. The thickness of the inner permanent magnet (9) and the outer permanent magnet (11) is h 1 and the number of layers is n The thickness of the yoke thrust plate (8) is h 2. The widths of the inner permanent magnet (9) and the outer permanent magnet (11) are: l The preset value for the air gap thickness between the positive-acting coil (7) and the yoke thrust plate (8) is... δ 10 The preset value for the air gap thickness between the reaction coil (14) and the yoke thrust plate (8) is... δ 20 The number of turns of the positive-acting coil (7) is N 1. The number of turns of the reaction coil (14) is N 2. The preset current value of the positive-acting coil (7) is I p0 The preset current value of the reaction coil (14) is I n0 Material parameters: The remanent magnetic flux density of the inner permanent magnet (9) and the outer permanent magnet (11) is... B r ; The oscillation interval with quasi-zero stiffness in any interval [ m , n ], m The lower limit of the interval n The upper limit of the interval; The second step is to obtain the calibrated bearing capacity through experiments and to obtain the expression through polynomial fitting. The specific implementation process of the second step is as follows: The calibration bearing capacity of the electro-permanent magnet composite thrust bearing was obtained by experiment when only the inner ring permanent magnet (9) and the outer ring permanent magnet (11) interacted. The calibration bearing capacity fitting expression for the entire axial movement range was obtained by polynomial fitting. F b ( z )as follows: In the formula, z This refers to the longitudinal displacement. k 1. k 2. k 3 and k 4 represents the polynomial fitting coefficients; The third step is to calculate the average resultant force in the selected interval and then calculate the corresponding displacement. The specific implementation process of the third step is as follows: Due to the fitting expression F b ( z The nonlinear monotonically increasing trend occurs throughout the entire fluctuation interval; therefore, any selected fluctuation interval [ m There exists a unique variable [n]. z 0 and the fluctuation range [ m [n] average resultant force F avg Correspondingly, the resultant force F avg and lateral movement z The parsing expression for 0 is as follows: In the formula, F b ( m The longitudinal displacement is m The rated bearing capacity at that time F b ( n The longitudinal displacement is n The rated bearing capacity at that time p and q To simplify the coefficients, they are calculated using the following formula: ω The cubic root of unity is 1, and it is calculated using the following formula; In the formula, i It is the imaginary unit, and i 2 =-1; Step 4: Set the control mode of the positive-acting coil (7) of the positive-acting floating unit; The specific implementation process of the fourth step is as follows: To control the electromagnetic attraction force generated by the positive-acting coil (7) on the yoke thrust plate (8), two control modes are provided: current control mode and air gap control mode. Assuming that the magnetomotive force generated by the positive-acting coil (7) falls entirely on the air gap between the positive-acting coil (7) and the yoke thrust plate (8), based on force balance, the output force of the positive-acting coil (7)... F ep It is calculated by the following formula: In the formula, z 1 represents the displacement interval variable during which the positive-acting coil (7) is in operation, and ; F b ( z 1 The longitudinal displacement is z 1 The rated bearing capacity at that time; μ 0 is the permeability of free space, and μ 0 = 4π × 10 -7 H / m; A For effective working cross-sectional area; I p ( z 1) The control current of the positive-acting coil (7) varies with the longitudinal displacement. z The change of 1 does not change the air gap thickness between the positive action coil (7) and the yoke thrust plate (8) in the current control mode; δ 1( z 1) The thickness of the air gap between the positive-acting coil (7) and the yoke thrust plate (8) varies with longitudinal movement. z The change in 1 does not change the control current of the positive-acting coil (7) in the air gap control mode; A , I p ( z 1) and δ 1( z 1) Calculated using the following formula: ； Step 5: Set the control mode of the reaction coil (14) of the reaction floating unit; The specific implementation process of step five is as follows: Similar to step four, based on the force balance, the output force of the reaction coil (14) F en It is calculated by the following formula: In the formula, z 2 is the displacement interval variable during which the reaction coil (14) is in operation, and ; F b ( z 2) The longitudinal displacement is z The rated bearing capacity at time 2; I n ( z 2) The control current of the reaction coil (14) varies with the longitudinal displacement. z The change in 2, under current control mode, is calculated by the following formula: δ 2( z 2) The amount of longitudinal movement of the air gap thickness between the reaction coil (14) and the yoke thrust plate (8). z The change of 2, in the air gap control mode, is calculated by the following formula: ； Step 6: Obtain the load-bearing capacity expression for the electro-permanent magnet composite thrust bearing, including the quasi-zero stiffness range; The specific implementation process of step six is ​​as follows: The load-bearing capacity of the electro-permanent magnet composite thrust bearing within the entire axial movement range, including the quasi-zero stiffness range. F ( z It can be expressed by the following formula: From the above formula, it can be seen that within any set displacement range [ m , n The load-bearing capacity of the electro-permanent magnet composite thrust bearing is constant. F avg Thus, the design of quasi-zero stiffness in any range of the electro-permanent magnet composite thrust bearing is completed.

2. The method for designing quasi-zero stiffness in any interval of a synchronous kinetic electro-permanent magnet composite thrust bearing according to claim 1, characterized in that, The synchronous kinetic electric-permanent magnet composite thrust bearing includes an output flange (1), an inner rotor back iron (2), a bearing cover (3), a support bearing (4), a distance sensor (5), a floating base (6), a positive action coil (7), a yoke thrust disk (8), an inner ring permanent magnet (9), an outer stator base (10), an outer ring permanent magnet (11), a hollow electric cylinder housing (12), an annular piston head (13), and a reaction coil (14). The inner ring permanent magnet (9) and the outer ring permanent magnet (11) are respectively magnetically attracted and installed on the smooth mounting surfaces of the inner rotor back iron (2) and the outer stator base (10); the yoke thrust plate (8) is interference-fitted with the shoulders at both ends of the inner rotor back iron (2), and the output flange (1) is fixed to the end of the inner rotor back iron (2) for connection with other parts of the shaft system; the hollow electric cylinder housing (12), the annular piston head (13) and the floating base (6) together form a synchronous axial actuator, and the floating base (6) is fixed on the output plane of the annular piston head (13); the support bearing (4), the distance sensor (5) and the positive action coil (7) near the left side of the bearing are embedded in the floating base (6) to form a positive action floating unit, and the electromagnetic force generated by the positive action coil (7) is opposite to the direction of the external force to increase the resultant force; the support bearing (4), the distance sensor (5) and the positive action coil (7) near the right ... support bearing (4), the distance sensor (5) and the positive action coil (7) together form a positive action floating unit, and the electromagnetic force generated by the positive action coil (7) is opposite to the direction of the external force to increase the resultant force; the support bearing (4), the distance sensor (5) and the positive action coil (7) near the right side of the bearing are embedded in the support bearing (4), the distance sensor (5) and the positive action coil (7) are embedded in the floating base (6) to form a positive action floating unit, and the electromagnetic force generated by the positive action coil (7) is opposite to the direction of the external force to increase the resultant force; the electromagnetic force generated by the positive action coil (7) and the electromagnetic The sensor (5) and the reaction coil (14) are also embedded in the floating base (6) to form a reaction floating unit. The electromagnetic force generated by the reaction coil (14) is in the same direction as the external force to reduce the resultant force. The support bearing (4) is used to provide radial support and maintain the stability in the non-load direction. It is fixed to the side of the floating base (6) by the bearing cover (3). The distance sensor (5) is used to measure the air gap thickness between the positive action coil (7), the reaction coil (14) and the yoke thrust plate (8) and provide real-time feedback. The annular piston head (13) is driven by the hydraulic oil in the cylinder to achieve reciprocating motion and can reach any set position by controlling the flow rate and pressure. The hollow electric cylinder housing (12) is fixed to both ends of the outer stator base (10) through the stop, so that the outer ring permanent magnet (11) is longitudinally fixed while the reaction force is effectively transmitted to the outer stator base (10).

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