Method and device for determining design parameters of Halbach array axial passive magnetic bearing

Abstract

The embodiment of the invention provides a Halbach array axial passive magnetic bearing design parameter determination method and device, and relates to the technical field of passive magnetic bearing design. The method comprises the following steps: determining the surface magnetic charge density at the center of each group of permanent magnet structure of the Halbach array and the surface magnetic charge density at the two sides of each group of permanent magnet structure of the Halbach array based on magnetostatics; according to the surface magnetic charge density at the center of each group of permanent magnet structure of the Halbach array and the surface magnetic charge density at the two sides of each group of permanent magnet structure of the Halbach array, determining a magnetic field energy mathematical model at air gaps of single groups of permanent magnets on the upper spherical surface and the lower spherical surface of the passive magnetic bearing; and determining the group number of the spherical axial permanent magnets according to the magnetic field energy mathematical model at the air gaps of the upper and lower spherical single-group permanent magnets of the passive magnetic bearing. By adopting the technical scheme, the design parameters of the passive magnetic bearing can be quickly determined, the passive magnetic bearing can be quickly applied to a corresponding scene, and the overall efficiency is improved.

Description

Technical Field

[0001] The disclosed embodiments relate to the technical field of passive magnetic bearing design, and in particular to a method and device for determining design parameters of a Halbach array axial passive magnetic bearing. Background Art

[0002] At present, my country's traditional industrial motors are supported by mechanical bearings. Due to the constraints of mechanical bearing friction and rotor vibration, they can only run at low speeds, which leads to low power density and low efficiency. In industrial applications such as high-pressure blowers, compressors, and vacuum pumps, multi-pole speed increase mechanisms are required, which leads to problems such as large systems, high energy consumption, and poor reliability. High-speed motors supported by magnetic bearings eliminate friction and wear, do not require lubrication, and have speeds of up to tens of thousands of rpm. They have the advantages of high power density, small size, light weight, and fast response. They can be used as a direct drive power source to connect to high-speed mechanical equipment, which can effectively improve system efficiency and have significant energy-saving effects. They are ideal support components for the future development of high-speed rotating power machinery.

[0003] Magnetic bearings can be divided into active magnetic bearings and passive magnetic bearings according to whether the magnetic force is controllable. The former can realize active magnetic force control through electromagnets, feedback control loops, sensors, power amplifiers and other units. However, the system structure is complex and is a high-performance bearing system that combines electromechanical systems. As a result, the reliability of the active magnetic bearing system is relatively low, and it requires external energy to support the normal operation of the system.

[0004] Passive magnetic bearings use the magnetic force generated by permanent magnets to achieve contactless suspension support for the moving and stationary parts of the system. At the same time, the energy of the moving part is converted into eddy current loss through the bearing damper, which quickly attenuates the axial oscillation of the moving part and improves the stability and reliability of the system. Compared with active magnetic bearings, passive magnetic bearings have a simple structure and do not require a control system. Therefore, they have high reliability, low loss, and do not require external energy, which has unique advantages in some special occasions.

[0005] Therefore, there is an urgent need for a method for determining the design parameters of a Halbach array axial passive magnetic bearing, which can quickly determine the design parameters of the passive magnetic bearing, enable the passive magnetic bearing to be quickly applied to the corresponding scenarios, and improve the overall efficiency. Summary of the invention

[0006] In order to solve the above technical problems or at least partially solve the above technical problems, an embodiment of the present disclosure provides a method and device for determining design parameters of a Halbach array axial passive magnetic bearing.

[0007] A first aspect of an embodiment of the present disclosure provides a method for determining design parameters of a Halbach array axial passive magnetic bearing, wherein the Halbach array axial passive magnetic bearing is used to withstand an axial force applied to a stator portion along a rotor portion, and generates an axial suspension force by forming a repulsive force through a permanent magnet combined by a Halbach array, and the method comprises: Based on magnetostatics, determine the surface magnetic charge density at the center of each group of permanent magnet structures of the Halbach array and the surface magnetic charge density on both sides of each group of permanent magnet structures of the Halbach array; Determine a mathematical model of magnetic field energy at the air gap of the single permanent magnet group on the upper and lower spherical surfaces of the passive magnetic bearing according to the surface magnetic charge density at the center of each permanent magnet structure of the Halbach array and the surface magnetic charge density on both sides of each permanent magnet structure of the Halbach array; The number of spherical axial permanent magnet groups is determined according to the mathematical model of the magnetic field energy at the air gap between the upper and lower spherical single permanent magnet groups of the passive magnetic bearing; wherein the number of spherical axial permanent magnet groups is the design parameter of the Halbach array axial passive magnetic bearing.

[0008] In one example, the method of determining the magnetic field energy mathematical model at the air gap of the upper and lower spherical single groups of permanent magnets of the passive magnetic bearing according to the surface magnetic charge density at the center of each group of permanent magnet structures of the Halbach array and the surface magnetic charge density on both sides of each group of permanent magnet structures of the Halbach array includes: Determine the main air gap magnetic field strength at the center of each group of permanent magnet structures and the air gap leakage magnetic field strength at the center of each group of permanent magnet structures according to the surface magnetic charge density at the center of each group of permanent magnet structures of the Halbach array; Determine the main air gap magnetic field strength at both sides of each group of permanent magnet structures and the air gap leakage magnetic field strength at both sides of each group of permanent magnet structures according to the surface magnetic charge density at both sides of each group of permanent magnet structures of the Halbach array; According to the main air gap magnetic field intensity at the center of each group of permanent magnet structures, the air gap leakage magnetic field intensity at the center of each group of permanent magnet structures, the main air gap magnetic field intensity at both sides of each group of permanent magnet structures and the air gap leakage magnetic field intensity at both sides of each group of permanent magnet structures, a mathematical model of the magnetic field energy at the air gaps of the single groups of permanent magnets on the upper and lower spherical surfaces of the passive magnetic bearing is determined.

[0009] In one example, determining the number of spherical axial permanent magnet groups according to the mathematical model of magnetic field energy at the air gap at the upper and lower spherical single groups of permanent magnets of the passive magnetic bearing includes: The mathematical model of the magnetic field energy at the air gap of the single set of permanent magnets on the upper and lower spherical surfaces of the passive magnetic bearing is derived to obtain the axial force generated by the single set of permanent magnets on the upper and lower spherical surfaces of the spherical passive magnetic bearing; According to the axial force generated by the single set of permanent magnets on the upper and lower spherical surfaces of the spherical passive magnetic bearing, the stiffness of the passive magnetic bearing of the single set of permanent magnets is obtained; The number of the spherical axial permanent magnet groups is determined according to the passive magnetic bearing stiffness of the single group of permanent magnets and the total passive magnetic bearing stiffness.

[0010] In one example, the method further includes: Based on the virtual displacement principle, the air gap magnetic field energy model of the damping permanent magnet pole of the Halbach array axial passive magnetic bearing is determined; Determining the damping force according to the air gap magnetic field energy model of the damping permanent magnet pole of the Halbach array axial passive magnetic bearing; According to the damping force, the bearing damping coefficient is obtained.

[0011] In one example, obtaining a bearing damping coefficient according to the damping force includes: The bearing damping coefficient is obtained according to the damping force and the rotor dynamics model.

[0012] In one example, after obtaining the bearing damping coefficient, the method further includes: According to the bearing damping coefficient, the thickness of the optimal damping conductor is determined; wherein the thickness of the optimal damping conductor is the design parameter of the Halbach array axial passive magnetic bearing.

[0013] A second aspect of the embodiments of the present disclosure provides a Halbach array axial passive magnetic bearing design parameter determination device, wherein the Halbach array axial passive magnetic bearing is used to withstand the axial force applied to the stator part along the rotor part, and the axial suspension force is generated by the repulsive force formed by the permanent magnets combined by the Halbach array, and the device includes: A first determination module is used to determine the surface magnetic charge density at the center of each group of permanent magnet structures of the Halbach array and the surface magnetic charge density on both sides of each group of permanent magnet structures of the Halbach array based on magnetostatics; The second determination module is used to determine the mathematical model of the magnetic field energy at the air gap of the upper and lower spherical single groups of permanent magnets of the passive magnetic bearing according to the surface magnetic charge density at the center of each group of permanent magnet structures of the Halbach array and the surface magnetic charge density on both sides of each group of permanent magnet structures of the Halbach array; The third determination module is used to determine the number of spherical axial permanent magnet groups according to the mathematical model of the magnetic field energy at the air gap between the upper and lower spherical single groups of permanent magnets of the passive magnetic bearing; wherein the number of spherical axial permanent magnet groups is the design parameter of the Halbach array axial passive magnetic bearing.

[0014] In one example, the second determining module is specifically configured to: Determine the main air gap magnetic field strength at the center of each group of permanent magnet structures and the air gap leakage magnetic field strength at the center of each group of permanent magnet structures according to the surface magnetic charge density at the center of each group of permanent magnet structures of the Halbach array; Determine the main air gap magnetic field strength at both sides of each group of permanent magnet structures and the air gap leakage magnetic field strength at both sides of each group of permanent magnet structures according to the surface magnetic charge density at both sides of each group of permanent magnet structures of the Halbach array; According to the main air gap magnetic field intensity at the center of each group of permanent magnet structures, the air gap leakage magnetic field intensity at the center of each group of permanent magnet structures, the main air gap magnetic field intensity at both sides of each group of permanent magnet structures and the air gap leakage magnetic field intensity at both sides of each group of permanent magnet structures, a mathematical model of the magnetic field energy at the air gaps of the single groups of permanent magnets on the upper and lower spherical surfaces of the passive magnetic bearing is determined.

[0015] A third aspect of an embodiment of the present disclosure provides an electronic device, the server comprising: a processor and a memory, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the processor executes the method of the first aspect above.

[0016] A fourth aspect of an embodiment of the present disclosure provides a computer-readable storage medium, in which a computer program is stored. When the computer program is executed by a processor, the method of the first aspect described above can be implemented.

[0017] The disclosed embodiment provides a method and device for determining design parameters of a Halbach array axial passive magnetic bearing, wherein the Halbach array axial passive magnetic bearing is used to withstand an axial force applied to a stator portion along a rotor portion, and generates an axial suspension force by forming a repulsive force through permanent magnets combined in the Halbach array. The method comprises: determining the surface magnetic charge density at the center of each group of permanent magnet structures of the Halbach array and the surface magnetic charge density on both sides of each group of permanent magnet structures of the Halbach array based on magnetostatics; determining a mathematical model of magnetic field energy at an air gap at a single group of permanent magnets on an upper and lower spherical surface of the passive magnetic bearing according to the surface magnetic charge density at the center of each group of permanent magnet structures of the Halbach array and the surface magnetic charge density on both sides of each group of permanent magnet structures of the Halbach array; determining the number of spherical axial permanent magnet groups according to the mathematical model of magnetic field energy at an air gap at a single group of permanent magnets on an upper and lower spherical surface of the passive magnetic bearing; wherein the number of spherical axial permanent magnet groups is a design parameter of the Halbach array axial passive magnetic bearing. By adopting this technical solution, the design parameters of the passive magnetic bearing can be quickly determined, and the passive magnetic bearing can be quickly applied to the corresponding scenarios, thereby improving the overall efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0020] Figure 1 It is a flow chart of a method for determining design parameters of a Halbach array axial passive magnetic bearing provided by an embodiment of the present disclosure; Figure 2 It is a schematic diagram of the structure of a spherical Halbach array repulsive axial passive magnetic bearing provided by an embodiment of the present disclosure; Figure 3 It is a structural schematic diagram of a Halbach array axial passive magnetic bearing design parameter determination device provided by an embodiment of the present disclosure; Figure 4 It is a structural schematic diagram of an electronic device in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0021] In order to more clearly understand the above-mentioned objectives, features and advantages of the present disclosure, the scheme of the present disclosure will be further described below. It should be noted that the embodiments of the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0022] In the following description, many specific details are set forth to facilitate a full understanding of the present disclosure, but the present disclosure may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present disclosure, rather than all of the embodiments.

[0023] Figure 1 The present invention provides a flow chart of a method for determining design parameters of a Halbach array axial passive magnetic bearing, which can be performed by an electronic device. The electronic device can be exemplarily understood as a device such as a mobile phone, a tablet computer, a laptop computer, a desktop computer, a smart TV, etc. The Halbach array axial passive magnetic bearing is used to withstand the axial force applied to the stator part along the rotor part, and the repulsive force is formed by the permanent magnets of the Halbach array combination to generate an axial suspension force, such as Figure 1 As shown, the method provided in this embodiment includes the following steps: S101. Determine the surface magnetic charge density at the center of each group of permanent magnet structures of the Halbach array and the surface magnetic charge density on both sides of each group of permanent magnet structures of the Halbach array based on magnetostatics.

[0024] In one example, the surface magnetic charge density at the center of each permanent magnet structure of the Halbach array is And the surface magnetic charge density on both sides of each permanent magnet structure of the Halbach array It can be determined by the following formula: The excitation capacity of the passive magnetic bearing is equivalent to the magnetic charge. Assuming that the magnetic charge is evenly distributed on the upper and lower spherical surfaces of the permanent magnet of the spherical axial passive magnetic bearing, the magnetic charge density on the upper spherical surface is , the magnetic charge density on the lower spherical surface is . From magnetostatics, we can get: ; ; in, σ * is the magnetic charge density on the spherical surface; J 0 is the magnetic pole magnetization intensity vector; is the unit vector in the normal direction of the end surface of the permanent magnet ring of the spherical axial passive magnetic bearing; μ 0 is the vacuum permeability, μ 0=4π×10 -7 H / M ; M is the magnetization intensity; H is the magnetic field intensity. Since the spherical axial passive magnetic bearing adopts the Halbach array structure, the upper and lower spherical permanent magnets both adopt a combined structure. Taking this structure as an example, three layers of permanent magnets are used as a group to form a Halbach array structure. Therefore, the normal direction of the end face of the permanent magnet ring at the center of each group of permanent magnet structures is the same as the magnetization direction, while the normal direction of the end face of the permanent magnet ring on both sides has a certain angle with the magnetization direction, so: ; ; Among them, the surface magnetic charge density at the center of each permanent magnet structure of the Halbach array is , the surface magnetic charge density on both sides of each permanent magnet structure of the Halbach array is , is the residual magnetization of the permanent magnet, It is the angle between the normal direction of the end face of the permanent magnet ring and the magnetization direction.

[0025] S102. Determine a mathematical model of the magnetic field energy at the air gaps of the upper and lower spherical single permanent magnet groups of the passive magnetic bearing based on the surface magnetic charge density at the center of each permanent magnet structure of the Halbach array and the surface magnetic charge density on both sides of each permanent magnet structure of the Halbach array.

[0026] In one example, according to the surface magnetic charge density at the center of each group of permanent magnet structures of the Halbach array and the surface magnetic charge density on both sides of each group of permanent magnet structures of the Halbach array, a mathematical model of the magnetic field energy at the air gap of the upper and lower spherical single groups of permanent magnets of the passive magnetic bearing is determined, including: According to the surface magnetic charge density at the center of each group of permanent magnet structures of the Halbach array, the main air gap magnetic field intensity at the center of each group of permanent magnet structures and the air gap leakage magnetic field intensity at the center of each group of permanent magnet structures are determined; According to the surface magnetic charge density on both sides of each group of permanent magnet structures of the Halbach array, the main air gap magnetic field intensity at both sides of each group of permanent magnet structures and the air gap leakage magnetic field intensity at both sides of each group of permanent magnet structures are determined; According to the main air gap magnetic field intensity at the center of each group of permanent magnet structures, the air gap leakage magnetic field intensity at the center of each group of permanent magnet structures, the main air gap magnetic field intensity at both sides of each group of permanent magnet structures and the air gap leakage magnetic field intensity at both sides of each group of permanent magnet structures, the mathematical model of the magnetic field energy at the air gap of a single group of permanent magnets on the upper and lower spherical surfaces of a passive magnetic bearing is determined.

[0027] In one example, since the magnetic bearing is in a changing motion stable state, the air gap magnetic field strength is also in a relatively changing stable state. Therefore, the main air gap magnetic field strength and the air gap leakage magnetic field strength of the permanent magnets at the center and the permanent magnets at both sides of each set of permanent magnet structures can be expressed as: ; ; ; ; in, B zc is the main air gap magnetic field strength at the center of each set of permanent magnet structures, B zclou is the air gap leakage magnetic field intensity at the center of each set of permanent magnet structures. B zb is the main air gap magnetic field strength on both sides of each set of permanent magnet structures, B zblou is the air gap leakage magnetic field intensity on both sides of each set of permanent magnet structures.

[0028] The axial force generated by the single set of permanent magnets on the upper and lower spherical surfaces of the passive magnetic bearing is calculated using the virtual displacement principle. First, the magnetic field energy in the air gap at the single set of permanent magnets on the upper and lower spherical surfaces of the passive magnetic bearing is calculated. The axial force of the spherical passive magnetic bearing is the inverse of the energy in the axial displacement. The mathematical model of the magnetic field energy in the air gap at the single set of permanent magnets on the upper and lower spherical surfaces of the passive magnetic bearing is: ; in, W It is the mathematical model of magnetic field energy in the air gap between the upper and lower spherical surfaces of a spherical passive magnetic bearing. R up and R downare the reference radius of the upper and lower spherical single-layer permanent magnets of the passive magnetic bearing, l pm is the radial thickness of the upper and lower spherical single-layer permanent magnets of the passive magnetic bearing, δ is the axial air gap between the upper and lower end surfaces of the permanent magnet ring of the spherical axial passive magnetic bearing, and z is the axial position change between the upper and lower spherical surfaces of the spherical axial passive magnetic bearing.

[0029] S103. Determine the number of spherical axial permanent magnet groups according to the mathematical model of the magnetic field energy at the air gaps between the upper and lower spherical single permanent magnet groups of the passive magnetic bearing; wherein the number of spherical axial permanent magnet groups is a design parameter of the Halbach array axial passive magnetic bearing.

[0030] In one example, according to the mathematical model of magnetic field energy at the air gap at the upper and lower spherical single-group permanent magnets of the passive magnetic bearing, the number of spherical axial permanent magnet groups is determined, including: The mathematical model of magnetic field energy at the air gap of the single set of permanent magnets on the upper and lower spherical surfaces of the passive magnetic bearing is derived to obtain the axial force generated by the single set of permanent magnets on the upper and lower spherical surfaces of the spherical passive magnetic bearing; According to the axial force generated by the single set of permanent magnets on the upper and lower spherical surfaces of the spherical passive magnetic bearing, the stiffness of the passive magnetic bearing with a single set of permanent magnets is obtained; The number of spherical axial permanent magnet groups is determined according to the passive magnetic bearing stiffness of a single group of permanent magnets and the total passive magnetic bearing stiffness.

[0031] In one example, the axial force generated by the single set of permanent magnets on the upper and lower spherical surfaces of the spherical passive magnetic bearing can be determined by the following formula: ; in, W It is the mathematical model of magnetic field energy in the air gap between the upper and lower spherical surfaces of a spherical passive magnetic bearing. R up and R down are the reference radius of the upper and lower spherical single-layer permanent magnets of the passive magnetic bearing, l pm is the radial thickness of the upper and lower spherical single-layer permanent magnets of the passive magnetic bearing, δ is the axial air gap between the upper and lower end surfaces of the permanent magnet ring of the spherical axial passive magnetic bearing, and z is the axial position change between the upper and lower spherical surfaces of the spherical axial passive magnetic bearing.

[0032] In order to provide a sufficiently large axial force, the passive magnetic bearing will use a structure with multiple sets of permanent magnets, and to ensure the convenience of passive magnetic bearing design, the magnetic flux density of each set of permanent magnets is equal. Therefore, when z=0, the stiffness of the passive magnetic bearing with a single set of permanent magnets can be obtained by the following formula: ; In one example, since the magnetic levitation measurement platform is placed vertically, the gravity of the moving part is in the same direction as the axial load force, and the load-bearing capacity required by the axial spherical passive magnetic bearing is the superposition of gravity and axial load force. In addition, in order to ensure reliable axial suspension, the maximum axial load-bearing capacity should have a certain safety factor based on these forces. Assuming that the weight of the moving part of the magnetic levitation measurement platform is m , the axial load force is F w , the maximum allowable axial displacement is △ z max , then the total passive magnetic bearing stiffness is: ; in, k sc is the safety factor, which is generally between 2 and 3; g is the acceleration due to gravity, g=9.8m / s 2 .

[0033] According to the above formula, the number of spherical axial permanent magnet groups N is: ; S104. Based on the virtual displacement principle, determine the air gap magnetic field energy model of the damping permanent magnet pole of the Halbach array axial passive magnetic bearing.

[0034] In one example, the damping force is calculated using the virtual displacement principle. First, the magnetic field energy in the air gap at the damping permanent magnet is calculated. The damping force is the inverse of the energy in the axial displacement. The magnetic field energy model of the air gap of the damping permanent magnet pole of the Halbach array axial passive magnetic bearing is: ; in, W To damp the magnetic field energy in the air gap at the permanent magnet, R ci and R co are the inner diameter and outer diameter of the damping permanent magnet respectively. h sl is the thickness of the damping conductor, B cz is the main magnetic field strength, B cz = B r ( δ+h sl +z ) / ( δ+h sl ); B czlou is the leakage magnetic field strength of the damping permanent magnet, B cz = B r ( δ+h sl +z ) / ( δ+h sl ).

[0035] S105. Determine the damping force according to the air gap magnetic field energy model of the damping permanent magnet pole of the Halbach array axial passive magnetic bearing.

[0036] In one example, the damping force may be determined by the following formula: ; in, is the damping force, W To damp the magnetic field energy in the air gap at the permanent magnet, R ci and R co are the inner diameter and outer diameter of the damping permanent magnet respectively. h sl is the thickness of the damping conductor, B cz is the main magnetic field strength, B cz = B r ( δ+h sl +z ) / ( δ+h sl ); B czlou is the leakage magnetic field strength of the damping permanent magnet, B cz = B r ( δ+h sl +z ) / ( δ+h sl ).

[0037] S106. Obtain the bearing damping coefficient according to the damping force.

[0038] In one example, the bearing damping coefficient is obtained according to the damping force, including: Based on the damping force and the rotor dynamics model, the bearing damping coefficient is obtained.

[0039] Assume that the displacement caused by the axial vibration of the moving part of the magnetic suspension measurement platform is: ; Where s is the axial vibration displacement of the platform moving parts, is the axial vibration amplitude of the platform moving part, ω is the axial vibration angular velocity of the platform moving part, and t is the time.

[0040] Then the velocity generated by the axial vibration of the moving part of the magnetic suspension measurement platform is: ; Where s is the axial vibration displacement of the platform moving parts, is the axial vibration amplitude of the platform moving part, ω is the axial vibration angular velocity of the platform moving part, and t is the time.

[0041] According to the law of conservation of energy, the eddy current loss consumed by the moving part of the magnetic suspension measurement platform is the mechanical energy of vibration. This part of energy is W d , the expression is: ; in, is the mechanical energy generated by the vibration of the platform moving parts, T is the axial vibration cycle time of the platform moving parts, is the time expression of the vibration damping force of the platform moving parts, and v is the axial vibration velocity of the platform moving parts.

[0042] Assume that the equivalent damping coefficient of the moving part of the magnetic levitation measurement platform is C d , then this part of energy can also be expressed as: ; in, is the mechanical energy generated by the vibration of the platform moving parts, T is the axial vibration cycle time of the platform moving parts, v is the axial vibration speed of the platform moving parts, t is the time, is the axial vibration amplitude of the platform moving parts, and ω is the axial vibration angular velocity of the platform moving parts.

[0043] According to the above formula, the damping coefficient of the motion bearing of the magnetic suspension measurement platform can be obtained: C d for: ; Where T is the axial vibration period of the platform moving parts, is the time expression of the vibration damping force of the platform moving parts, v is the axial vibration velocity of the platform moving parts, t is the time, is the axial vibration amplitude of the platform moving parts, and ω is the axial vibration angular velocity of the platform moving parts.

[0044] S107. Determine the thickness of the optimal damping conductor according to the bearing damping coefficient; wherein the thickness of the optimal damping conductor is a design parameter of the Halbach array axial passive magnetic bearing.

[0045] The function of the axial damper is to suppress the axial vibration caused by rigid mode or load disturbance, so before design, modal analysis is first performed to obtain the axial vibration frequency. Assume that the axial resonance speed obtained by analysis is n z , then the required damping coefficient is: ; in, λ d is the logarithmic attenuation rate required for the damping system, which is generally required to be between 0.7 and 1, and m is the mass.

[0046] The relationship between the damping force and the thickness of the stator copper sheet is that as the thickness of the copper sheet increases, the damping force first increases and then decreases. Therefore, the optimal thickness with the maximum damping force can be obtained by solving the differential equation to obtain the thickness of the optimal damping conductor: ; Among them, the thickness of the optimal damping conductor is , the damping force is .

[0047] For a clearer explanation, see Figure 2 A schematic diagram of the structure of a spherical Halbach array repulsive type axial passive magnetic bearing is shown. Figure 2 Mark 1 is a rotor magnetizer, mark 2 is a rotor mounting sleeve, mark 3 is a first rotor permanent magnet, mark 4 is a second rotor permanent magnet, mark 5 is a third rotor permanent magnet, mark 6 is a fourth rotor permanent magnet, mark 7 is a fifth rotor permanent magnet, mark 8 is a sixth rotor permanent magnet, mark 9 is a damping permanent magnet, mark 10 is a stator magnetizer, mark 11 is a stator mounting sleeve, mark 12 is a first stator permanent magnet, mark 13 is a second stator permanent magnet, mark 14 is a third stator permanent magnet, mark 15 is a fourth stator permanent magnet, mark 16 is a fifth stator permanent magnet, mark 17 is a sixth stator permanent magnet, mark 18 is a damping conductor and mark 19 is an air gap of a passive magnetic bearing.

[0048] In one example, the Halbach array axial passive magnetic bearing can withstand the axial force applied to the stator along the rotor part, and the repulsive force is generated by the axial combination of the Halbach array permanent magnets to generate axial suspension force, thereby realizing the axial single-degree-of-freedom contactless suspension support of the rotor part. At the same time, the damping permanent magnet can be used to generate magnetic flux changes on the damping conductor and generate eddy currents, thereby converting the axial vibration energy of the rotor into heat energy, rapidly attenuating the axial oscillation of the rotor, and restoring the rotor to a stable state. When the rotor part produces an axial displacement upward, it moves downward by relying on the gravity of the rotor part itself, until the gravity of the rotor part itself and the repulsive force between the permanent magnets of the Halbach array combination reach a balance, thereby achieving stable suspension of the rotor part; when the rotor part produces an axial displacement downward, it moves upward by relying on the repulsive force between the permanent magnets of the axial combination of the Halbach array, until the repulsive force between the paired permanent magnets and the gravity of the rotor part itself reach a balance, thereby achieving stable suspension of the rotor part; when there is an angular deflection between the geometric axis of the rotor part of the magnetic bearing and the geometric axis of its stator part, because the center of the sphere of the magnetic pole surface of the rotor part coincides with the center of the sphere of the magnetic pole surface of the stator part, at the stator magnetic pole surface, the repulsive force exerted on the rotor part is always along the radial direction of the spherical surface of the rotor part of the magnetic bearing, and all passes through the center of the sphere of the magnetic pole surface of the rotor part, thereby eliminating the interference force caused by uneven air gap and improving the suspension accuracy of the magnetic bearing.

[0049] The disclosed embodiment provides a method for determining the design parameters of a Halbach array axial passive magnetic bearing, wherein the Halbach array axial passive magnetic bearing is used to withstand the axial force applied to the stator portion along the rotor portion, and the axial suspension force is generated by the repulsive force formed by the permanent magnets of the Halbach array combination. The method includes: determining the surface magnetic charge density at the center of each group of permanent magnet structures of the Halbach array and the surface magnetic charge density on both sides of each group of permanent magnet structures of the Halbach array based on magnetostatics; determining the magnetic field energy mathematical model at the air gap of the upper and lower spherical single groups of permanent magnets of the passive magnetic bearing according to the surface magnetic charge density at the center of each group of permanent magnet structures of the Halbach array and the surface magnetic charge density on both sides of each group of permanent magnet structures of the Halbach array; determining the number of spherical axial permanent magnet groups according to the magnetic field energy mathematical model at the air gap of the upper and lower spherical single groups of permanent magnets of the passive magnetic bearing; wherein the number of spherical axial permanent magnet groups is the design parameter of the Halbach array axial passive magnetic bearing. By adopting the technical solution, the design parameters of the passive magnetic bearing can be quickly determined, and the passive magnetic bearing can be quickly applied to the corresponding scene to improve the overall efficiency.

[0050] Figure 3: is a schematic diagram of a Halbach array axial passive magnetic bearing design parameter determination device provided by an embodiment of the present disclosure. The passive magnetic bearing design parameter determination device can be understood as the above-mentioned electronic device or a partial functional module in the above-mentioned electronic device. The Halbach array axial passive magnetic bearing is used to withstand the axial force applied to the stator part along the rotor part, and the repulsive force is formed by the permanent magnets combined by the Halbach array to generate an axial suspension force, such as Figure 3 As shown, the Halbach array axial passive magnetic bearing design parameter determination device 30 includes: A first determination module 301 is used to determine the surface magnetic charge density at the center of each group of permanent magnet structures of the Halbach array and the surface magnetic charge density on both sides of each group of permanent magnet structures of the Halbach array based on magnetostatics; The second determination module 302 is used to determine the mathematical model of the magnetic field energy at the air gap of the single permanent magnet group on the upper and lower spherical surfaces of the passive magnetic bearing according to the surface magnetic charge density at the center of each permanent magnet structure of the Halbach array and the surface magnetic charge density on both sides of each permanent magnet structure of the Halbach array; The third determination module 303 is used to determine the number of spherical axial permanent magnet groups according to the mathematical model of the magnetic field energy at the air gap between the upper and lower spherical single permanent magnet groups of the passive magnetic bearing; wherein the number of spherical axial permanent magnet groups is a design parameter of the Halbach array axial passive magnetic bearing.

[0051] In one example, the second determining module 302 is specifically configured to: According to the surface magnetic charge density at the center of each group of permanent magnet structures of the Halbach array, the main air gap magnetic field intensity at the center of each group of permanent magnet structures and the air gap leakage magnetic field intensity at the center of each group of permanent magnet structures are determined; According to the surface magnetic charge density on both sides of each group of permanent magnet structures of the Halbach array, the main air gap magnetic field intensity at both sides of each group of permanent magnet structures and the air gap leakage magnetic field intensity at both sides of each group of permanent magnet structures are determined; According to the main air gap magnetic field intensity at the center of each group of permanent magnet structures, the air gap leakage magnetic field intensity at the center of each group of permanent magnet structures, the main air gap magnetic field intensity at both sides of each group of permanent magnet structures and the air gap leakage magnetic field intensity at both sides of each group of permanent magnet structures, the mathematical model of the magnetic field energy at the air gap of a single group of permanent magnets on the upper and lower spherical surfaces of a passive magnetic bearing is determined.

[0052] In one example, the third determining module 303 is specifically configured to: The mathematical model of magnetic field energy at the air gap of the single set of permanent magnets on the upper and lower spherical surfaces of the passive magnetic bearing is derived to obtain the axial force generated by the single set of permanent magnets on the upper and lower spherical surfaces of the spherical passive magnetic bearing; According to the axial force generated by the single set of permanent magnets on the upper and lower spherical surfaces of the spherical passive magnetic bearing, the stiffness of the passive magnetic bearing with a single set of permanent magnets is obtained; The number of spherical axial permanent magnet groups is determined according to the passive magnetic bearing stiffness of a single group of permanent magnets and the total passive magnetic bearing stiffness.

[0053] In one example, the apparatus 30 further includes: The fourth determination module 304 is used to determine the air gap magnetic field energy model of the damping permanent magnet pole of the Halbach array axial passive magnetic bearing based on the virtual displacement principle; A fifth determination module 305 is used to determine the damping force according to the air gap magnetic field energy model of the damping permanent magnet pole of the Halbach array axial passive magnetic bearing; The sixth determination module 306 is configured to obtain a bearing damping coefficient according to the damping force.

[0054] In one example, the sixth determination module 306 is specifically configured to obtain a bearing damping coefficient according to the damping force and the rotor dynamics model.

[0055] In one example, the apparatus 30 further includes: The seventh determination module 307 is used to determine the thickness of the optimal damping conductor according to the bearing damping coefficient; wherein the thickness of the optimal damping conductor is a design parameter of the Halbach array axial passive magnetic bearing.

[0056] The device provided in this embodiment can execute the method of any of the above embodiments, and its execution method and beneficial effects are similar, which will not be repeated here.

[0057] An embodiment of the present disclosure further provides an electronic device, which includes: a memory, in which a computer program is stored; and a processor, which is used to execute the computer program. When the computer program is executed by the processor, the method of any of the above embodiments can be implemented.

[0058] For example, Figure 4 Schematic diagram of the structure of an electronic device in the embodiment of the present disclosure. Figure 4 , which shows a schematic diagram of the structure of an electronic device 1000 suitable for implementing the embodiment of the present disclosure. The electronic device 1000 in the embodiment of the present disclosure may include but is not limited to mobile terminals such as mobile phones, notebook computers, digital broadcast receivers, PDAs (personal digital assistants), PADs (tablet computers), PMPs (portable multimedia players), vehicle terminals (such as vehicle navigation terminals), etc., and fixed terminals such as digital TVs, desktop computers, etc. Figure 4 The electronic device shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present disclosure.

[0059] like Figure 4As shown, the electronic device 1000 may include a processing device (e.g., a central processing unit, a graphics processing unit, etc.) 1001, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 1002 or a program loaded from a storage device 1008 to a random access memory (RAM) 1003. In the RAM 1003, various programs and data required for the operation of the electronic device 1000 are also stored. The processing device 1001, the ROM 1002, and the RAM 1003 are connected to each other via a bus 1004. An input / output (I / O) interface 1005 is also connected to the bus 1004.

[0060] Typically, the following devices may be connected to the I / O interface 1005: an input device 1006 including, for example, a touch screen, a touch pad, a keyboard, a mouse, a camera, a microphone, an accelerometer, a gyroscope, etc.; an output device 1007 including, for example, a liquid crystal display (LCD), a speaker, a vibrator, etc.; a storage device 1008 including, for example, a magnetic tape, a hard disk, etc.; and a communication device 1009. The communication device 1009 may allow the electronic device 1000 to communicate with other devices wirelessly or by wire to exchange data. Although Figure 4 The electronic device 1000 is shown with various devices, but it should be understood that it is not required to implement or possess all the devices shown. More or fewer devices may be implemented or possessed instead.

[0061] In particular, according to an embodiment of the present disclosure, the process described above with reference to the flowchart can be implemented as a computer software program. For example, an embodiment of the present disclosure includes a computer program product, which includes a computer program carried on a non-transitory computer-readable medium, and the computer program contains program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network through a communication device 1009, or installed from a storage device 1008, or installed from a ROM 1002. When the computer program is executed by the processing device 1001, the above-mentioned functions defined in the method of the embodiment of the present disclosure are executed.

[0062] It should be noted that the computer-readable medium mentioned above in the present disclosure may be a computer-readable signal medium or a computer-readable storage medium or any combination of the above two. The computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present disclosure, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, device or device. In the present disclosure, a computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, which carries a computer-readable program code. This propagated data signal may take a variety of forms, including but not limited to an electromagnetic signal, an optical signal, or any suitable combination of the above. Computer readable signal media may also be any computer readable medium other than computer readable storage media, which may send, propagate or transmit a program for use by or in conjunction with an instruction execution system, apparatus or device. The program code contained on the computer readable medium may be transmitted using any appropriate medium, including but not limited to: wires, optical cables, RF (radio frequency), etc., or any suitable combination of the above.

[0063] In some embodiments, the client and the server may communicate using any currently known or future developed network protocol such as HTTP (HyperText Transfer Protocol), and may be interconnected with any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include a local area network ("LAN"), a wide area network ("WAN"), an internet (e.g., the Internet), and a peer-to-peer network (e.g., an ad hoc peer-to-peer network), as well as any currently known or future developed network.

[0064] The computer-readable medium may be included in the electronic device, or may exist independently without being incorporated into the electronic device.

[0065] The computer-readable medium carries one or more programs. When the one or more programs are executed by the electronic device, the electronic device: determines the surface magnetic charge density at the center of each group of permanent magnet structures of the Halbach array and the surface magnetic charge density on both sides of each group of permanent magnet structures of the Halbach array based on magnetostatics; determines the mathematical model of the magnetic field energy at the air gap of the upper and lower spherical single groups of permanent magnets of the passive magnetic bearing according to the surface magnetic charge density at the center of each group of permanent magnet structures of the Halbach array and the surface magnetic charge density on both sides of each group of permanent magnet structures of the Halbach array; determines the number of spherical axial permanent magnet groups according to the mathematical model of the magnetic field energy at the air gap of the upper and lower spherical single groups of permanent magnets of the passive magnetic bearing; wherein the number of spherical axial permanent magnet groups is the design parameter of the Halbach array axial passive magnetic bearing.

[0066] Computer program code for performing the operations of the present disclosure may be written in one or more programming languages ​​or a combination thereof, including, but not limited to, object-oriented programming languages, such as Java, Smalltalk, C++, and conventional procedural programming languages, such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0067] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present disclosure. In this regard, each square box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some implementations as replacements, the functions marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two square boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0068] The units involved in the embodiments described in the present disclosure may be implemented by software or hardware, wherein the name of a unit does not, in some cases, limit the unit itself.

[0069] The functions described above herein may be performed at least in part by one or more hardware logic components. For example, without limitation, exemplary types of hardware logic components that may be used include: field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), complex programmable logic devices (CPLDs), and the like.

[0070] In the context of the present disclosure, a machine-readable medium may be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, device, or equipment. A machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or device, or any suitable combination of the foregoing. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0071] The embodiments of the present disclosure also provide a computer-readable storage medium, in which a computer program is stored. When the computer program is executed by a processor, the method of any of the above embodiments can be implemented. The execution method and beneficial effects are similar and will not be repeated here.

[0072] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0073] The above description is only a specific embodiment of the present disclosure, so that those skilled in the art can understand or implement the present disclosure. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure will not be limited to the embodiments described herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for determining design parameters of a Halbach array axial passive magnetic bearing, characterized in that: The Halbach array axial passive magnetic bearing is used to withstand the axial force applied to the stator part along the rotor part, and the axial suspension force is generated by the repulsive force formed by the permanent magnets combined by the Halbach array. The method includes: Based on magnetostatics, determine the surface magnetic charge density at the center of each group of permanent magnet structures of the Halbach array and the surface magnetic charge density on both sides of each group of permanent magnet structures of the Halbach array; Determine a mathematical model of magnetic field energy at the air gap of the single permanent magnet group on the upper and lower spherical surfaces of the passive magnetic bearing according to the surface magnetic charge density at the center of each permanent magnet structure of the Halbach array and the surface magnetic charge density on both sides of each permanent magnet structure of the Halbach array; The number of spherical axial permanent magnet groups is determined according to the mathematical model of the magnetic field energy at the air gap between the upper and lower spherical single permanent magnet groups of the passive magnetic bearing; wherein the number of spherical axial permanent magnet groups is the design parameter of the Halbach array axial passive magnetic bearing.

2. The method according to claim 1, characterized in that The method of determining the magnetic field energy mathematical model at the air gap of the single permanent magnet group on the upper and lower spherical surfaces of the passive magnetic bearing according to the surface magnetic charge density at the center of each permanent magnet structure of the Halbach array and the surface magnetic charge density on both sides of each permanent magnet structure of the Halbach array comprises: Determine the main air gap magnetic field strength at the center of each group of permanent magnet structures and the air gap leakage magnetic field strength at the center of each group of permanent magnet structures according to the surface magnetic charge density at the center of each group of permanent magnet structures of the Halbach array; Determine the main air gap magnetic field strength at both sides of each group of permanent magnet structures and the air gap leakage magnetic field strength at both sides of each group of permanent magnet structures according to the surface magnetic charge density at both sides of each group of permanent magnet structures of the Halbach array; According to the main air gap magnetic field intensity at the center of each group of permanent magnet structures, the air gap leakage magnetic field intensity at the center of each group of permanent magnet structures, the main air gap magnetic field intensity at both sides of each group of permanent magnet structures and the air gap leakage magnetic field intensity at both sides of each group of permanent magnet structures, a mathematical model of the magnetic field energy at the air gaps of the single groups of permanent magnets on the upper and lower spherical surfaces of the passive magnetic bearing is determined.

3. The method according to claim 1, characterized in that The method of determining the number of spherical axial permanent magnet groups according to the mathematical model of the magnetic field energy at the air gap at the single set of permanent magnets on the upper and lower spherical surfaces of the passive magnetic bearing comprises: The mathematical model of the magnetic field energy at the air gap of the single set of permanent magnets on the upper and lower spherical surfaces of the passive magnetic bearing is derived to obtain the axial force generated by the single set of permanent magnets on the upper and lower spherical surfaces of the spherical passive magnetic bearing; According to the axial force generated by the single set of permanent magnets on the upper and lower spherical surfaces of the spherical passive magnetic bearing, the stiffness of the passive magnetic bearing of the single set of permanent magnets is obtained; The number of the spherical axial permanent magnet groups is determined according to the passive magnetic bearing stiffness of the single group of permanent magnets and the total passive magnetic bearing stiffness.

4. The method according to claim 1, characterized in that: The method further comprises: Based on the virtual displacement principle, the air gap magnetic field energy model of the damping permanent magnet pole of the Halbach array axial passive magnetic bearing is determined; Determining the damping force according to the air gap magnetic field energy model of the damping permanent magnet pole of the Halbach array axial passive magnetic bearing; According to the damping force, the bearing damping coefficient is obtained.

5. The method according to claim 4, characterized in that The step of obtaining the bearing damping coefficient according to the damping force comprises: The bearing damping coefficient is obtained according to the damping force and the rotor dynamics model.

6. The method according to any one of claims 4-5, characterized in that: After obtaining the bearing damping coefficient, the method further includes: According to the bearing damping coefficient, the thickness of the optimal damping conductor is determined; wherein the thickness of the optimal damping conductor is the design parameter of the Halbach array axial passive magnetic bearing.

7. A Halbach array axial passive magnetic bearing design parameter determination device, characterized in that: The Halbach array axial passive magnetic bearing is used to withstand the axial force applied to the stator part along the rotor part, and the axial suspension force is generated by the repulsive force formed by the permanent magnets combined by the Halbach array. The device includes: A first determination module is used to determine the surface magnetic charge density at the center of each group of permanent magnet structures of the Halbach array and the surface magnetic charge density on both sides of each group of permanent magnet structures of the Halbach array based on magnetostatics; The second determination module is used to determine the mathematical model of the magnetic field energy at the air gap of the upper and lower spherical single groups of permanent magnets of the passive magnetic bearing according to the surface magnetic charge density at the center of each group of permanent magnet structures of the Halbach array and the surface magnetic charge density on both sides of each group of permanent magnet structures of the Halbach array; The third determination module is used to determine the number of spherical axial permanent magnet groups according to the mathematical model of the magnetic field energy at the air gap between the upper and lower spherical single groups of permanent magnets of the passive magnetic bearing; wherein the number of spherical axial permanent magnet groups is the design parameter of the Halbach array axial passive magnetic bearing.

8. The device according to claim 7, characterized in that The second determining module is specifically used to: Determine the main air gap magnetic field strength at the center of each group of permanent magnet structures and the air gap leakage magnetic field strength at the center of each group of permanent magnet structures according to the surface magnetic charge density at the center of each group of permanent magnet structures of the Halbach array; Determine the main air gap magnetic field strength at both sides of each group of permanent magnet structures and the air gap leakage magnetic field strength at both sides of each group of permanent magnet structures according to the surface magnetic charge density at both sides of each group of permanent magnet structures of the Halbach array; According to the main air gap magnetic field intensity at the center of each group of permanent magnet structures, the air gap leakage magnetic field intensity at the center of each group of permanent magnet structures, the main air gap magnetic field intensity at both sides of each group of permanent magnet structures and the air gap leakage magnetic field intensity at both sides of each group of permanent magnet structures, a mathematical model of the magnetic field energy at the air gaps of the single groups of permanent magnets on the upper and lower spherical surfaces of the passive magnetic bearing is determined.

9. An electronic device, characterized in that: include: A processor and a memory, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the processor executes the method according to any one of claims 1 to 6.

10. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 6 is implemented.

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