CN113422496B - High-positioning-precision mixed magnetic source magnetic screw and multi-harmonic cooperative modulation method thereof - Google Patents

Abstract

The invention discloses a high-positioning-precision mixed magnetic source magnetic screw and a multi-harmonic cooperative modulation method thereof, wherein the high-positioning-precision mixed magnetic source magnetic screw comprises a magnetic nut and a magnetic screw rod which are coaxially arranged; according to the characteristics of the spiral structure, through the space matching of the permanent magnet and the magnetic modulation module, a new effective harmonic order is introduced, so that the modulation mechanism in the linear direction is satisfied, the modulation mechanism in the circumferential direction is satisfied, and multi-harmonic cooperative modulation is realized; an excitation winding is wound in the magnetic adjusting module, so that the air gap field of the magnetic lead screw can be adjusted, and the positioning precision is improved. The invention provides a high-positioning-precision mixed magnetic source magnetic lead screw, which solves the defects of single magnetic field modulation, large magnetic leakage, insufficient positioning precision and the like of the conventional magnetic lead screw on the premise of ensuring high reliability and high thrust density.

Description

A hybrid magnetic source magnetic lead screw with high positioning accuracy and its multi-harmonic coordinated modulation method

technical field

The invention relates to a design method of a mixed magnetic source magnetic lead screw with high positioning accuracy and multi-harmonic coordinated modulation, and is especially designed to a helical magnetic drive and a mixed magnetic source magnetic field modulation technology, which is suitable for aerospace, high-end machine tools and other high positioning accuracy, high The application of thrust density belongs to the technical field of design and manufacture of new electric actuators.

Background technique

The magnetic screw has the characteristics of high thrust density, no contact friction, and simple maintenance, so it has a good application prospect in many fields such as aerospace, marine power generation and so on. At present, most of the research on magnetic screw is the surface-mounted magnetic screw with alternating N and S poles of permanent magnets radially magnetized. However, this structure has the characteristics of single magnetic field modulation, large magnetic leakage, and unadjustable air gap magnetic field. and other disadvantages.

The document IEEE Transactions on Industrial Electronics, 65(9): 7536-7547, 2018 (Design optimization and test of a radially magnetized magnetic screw with discretized PMs) introduces a surface-mounted magnetic screw that incorporates radially magnetized helical The N and S poles of the permanent magnet are alternately attached to the electrician iron rod. Compared with other linear drives, although this structure can greatly improve the thrust density and increase the magnetic induction intensity of the air gap, the introduced magnetic screw has the disadvantages of single magnetic field modulation, large magnetic leakage, and unadjustable air gap magnetic field. This in turn affects the thrust density and positioning top, thus restricting the application of magnetic lead screws in high dynamic fields such as aerospace.

The document IEEE Transactions on Magnetics, 50(11): 8205004, 2014 (Electromagnetic lead screw for potential wave energy application) introduces an electromagnetic magnetic lead screw, which is made of an electric iron rod into a spiral groove structure. A coil is wound, and a direct current is passed into the coil to obtain a spiral magnetic circuit. This structure can realize the adjustment of the air gap magnetic field of the magnetic lead screw and improve the positioning accuracy, but the introduced electric excitation type magnetic lead screw. Due to the use of electrical excitation, the magnetic induction intensity will drop significantly. The resulting thrust density is less than one-fourth of that of a permanent magnet type lead screw. Therefore, it has important theoretical significance and practical value to improve the thrust density of the magnetic screw under the premise of realizing the adjustable air-gap magnetic field.

Chinese invention patent ZL201610821273.1 discloses a magnetic field modulation type magnetic screw, which is actually a magnetic screw structure that satisfies magnetic field modulation. The rotor permanent magnets are alternately distributed with N and S poles spirally, and the number of pole pairs in the linear direction is p _r ; the mover is composed of a spiral electric iron ring, and the number of pole pairs in the linear direction is n _t ; the stator permanent magnets are alternately distributed with N and S poles spirally, and the number of pole pairs in the linear direction is p _s ; and satisfy p _s = _{n t} -pr linear magnetic field modulation relationship. In this structure, it is composed of three parts: mover, stator and rotor, and there are two layers of air gaps, which greatly increases the complexity of manufacturing. Document IEEE Transactions on Industry Applications, 54(6): 5736-5747, 2018 (Designing and experimentally testing a magnetically geared lead screw), designed and manufactured a magnetic field modulated magnetic lead screw prototype, and experimentally verified the magnetic field modulation effect of the magnetic lead screw , due to manufacturing complexity and machining accuracy, the measured thrust is less than 40% of the theoretical analysis.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the defects of the prior art, and propose a mixed magnetic source magnetic lead screw with high positioning accuracy and its multi-harmonic coordinated modulation mechanism. The magnetic lead screw has the disadvantages of single magnetic field modulation and unadjustable air gap magnetic field, which significantly improves the force density and positioning accuracy of the existing permanent magnet actuator.

Specifically, the hybrid magnetic source magnetic screw with high positioning accuracy proposed by the present invention is realized by adopting the following technical solutions: a hybrid magnetic source magnetic screw with high positioning accuracy, which sequentially includes a magnetic nut (1), The magnetic lead screw (2) is placed coaxially; wherein, there is an air gap between the magnetic nut (1) and the magnetic lead screw (2), and the length of the air gap is selected according to the size and requirements of the magnetic lead screw.

The magnetic nut (1) is composed of an axially magnetized helical permanent magnet A1, a helical permanent magnet A2, and a helical magnetic adjustment module B1, wherein the magnetizing directions of the helical permanent magnet A1 and the helical permanent magnet A2 point to the helix. Magnetic adjustment module B1; the leads of the helical permanent magnet A1, the helical permanent magnet A2, and the helical magnetic adjustment module B1 are all λ;

The magnetic screw rod (2) is composed of an axially magnetized helical permanent magnet A3, a helical permanent magnet A4, a helical magnetic adjustment module B2, a helical winding C1, and a helical winding C2, wherein the helical permanent magnet A3, the helical The magnetization direction of the permanent magnet A4 points to the helical magnetic modulation module B2; the current directions of the helical winding C1 and the helical winding C2 are opposite. When the mixed magnetic source magnetic screw increases the thrust density at a fixed operating point, the amplitude of the helical winding C1 is positive. value, the amplitude of the helical winding C2 is a negative value. Similarly, when the mixed magnetic source magnetic screw reduces the thrust density at a fixed operating point, the amplitude of the helical winding C1 is a negative value and the amplitude of the helical winding C2 is a positive value. By changing the amplitude and direction of the current of the helical winding C1 and the helical winding C2, the air-gap magnetic field adjustment of the hybrid magnetic source magnetic lead screw is realized. The leads of the helical permanent magnet A3, the helical permanent magnet A4, the helical magnetic modulation module B2, the helical winding C1, and the helical winding C2 are all λ;

In the magnetic nut (1), the permanent magnetic fields generated by the helical permanent magnet A1 and the helical permanent magnet A2 are generated once, three times, and five times in the axial direction and the circumferential direction respectively after passing through the helical magnetic adjustment module B1. Sub-odd harmonic amplitude; Similarly, in the magnetic screw (2), the permanent magnetic field generated by the helical permanent magnet A3 and the helical permanent magnet A4, after passing through the helical magnetic adjustment module B2, generates a The nut (1) has the same harmonic order, and by adjusting the amplitude and direction of the current in the helical winding C1 and the helical winding C2, the harmonic amplitude is adjusted, and the magnetic nut (1) and the magnetic screw (2) are multiplied. Harmonic co-modulation.

Further, the magnetization directions of the helical permanent magnet A1 and the helical permanent magnet A2 are directed to the helical magnetization module B1, and the magnetization directions of the helical permanent magnet A3 and the helical permanent magnet A4 are directed to the helical magnetization module B2. According to the principle of minimum reluctance, the spiral permanent magnetic field is drawn out through the magnetic adjustment module, which significantly reduces the leakage of the permanent magnetic field.

Further, in the magnetic nut (1), the leads of the helical permanent magnet A1, the helical permanent magnet A2, and the helical magnetic adjustment module B1 are all λ, ensuring that the axial direction of the helical permanent magnet A1 and the helical permanent magnet A2 is λ. If the lengths are the same, the axial length of the helical permanent magnet A1 and the helical permanent magnet A2 is l _pm =λ/2-l _t , where l _t is the axial length of the magnetic modulation module B1;

Further, in the magnetic screw rod (2), the leads of the helical permanent magnet A3, the helical permanent magnet A4, the helical magnetic adjustment module B2, the helical winding C1, and the helical winding C2 are all λ, ensuring that the helical permanent magnet A3 The axial lengths of the helical permanent magnets A4 and A4 are the same, then the axial lengths of the helical permanent magnets A3 and A4 are l _pm =λ/2-l _t , where l _t is the axial direction of the magnetic modulation module B2 Length, the modulating tooth width l _r =(l _t -2l _a )/3 of the magnetic modulation module B2, and the length of l _a is the width of the helical grooves of the helical winding C1 and the helical winding C2.

A high-positioning precision hybrid magnetic source magnetic lead screw and a multi-harmonic coordinated modulation design method, comprising the following steps:

Step 1, in the magnetic nut (1), the leads of the helical permanent magnet A1, the helical permanent magnet A2, and the helical magnetic adjustment module B1 are all λ, to ensure that in the magnetic screw rod (2), the helical permanent magnet A3 , The lead lengths of the helical permanent magnet A4, the helical magnetic modulation module B2, the helical winding C1, and the helical winding C2 are kept the same;

Step 2, while ensuring that the length of the helical lead λ is consistent, it is also necessary to ensure that the axial lengths of the helical permanent magnet A1, the helical permanent magnet A2, the helical permanent magnet A3, and the helical permanent magnet A4 are all 1 _μm , The axial lengths of the helical magnetic adjustment module B2 and the spiral magnetic adjustment module B1 are both l _t . The width of the modulating tooth is l _r , which satisfies the multi-harmonic coordinated modulation mechanism of the helical magnetic field;

Step 3: Under the condition that the multi-harmonic coordinated modulation mechanism of the helical magnetic field is satisfied, the linear direction and the circumferential direction of the magnetic nut (1) and the magnetic screw (2) are cross-sectioned. The air-gap magnetic density is extracted, and the 1st, 3rd, and 5th order axial harmonic magnetic fields can be obtained. Similarly, by extracting the magnetic density of the circular air gap within 2π of a circle, the 1st, 3rd, and 5th order circular harmonic magnetic fields of the same order can be obtained, which not only satisfy the modulation mechanism in the linear direction, but also satisfy the modulation in the circular direction. mechanism;

Step 4: In the "E-type" slot of the helical magnetic adjustment module B2 of the magnetic screw rod (2), two sets of helical windings are wound, namely the helical winding C1 and the helical winding C2. When the thrust density is increased at the fixed operating point, the amplitude of the helical winding C1 is positive and the amplitude of the helical winding C2 is negative; on the contrary, when the mixed magnetic source magnetic screw reduces the thrust density at the fixed operating point, the amplitude of the helical winding C1 is negative. is a negative value, and the amplitude of the spiral winding C2 is a positive value. According to the actual operating conditions, currents of different directions and amplitudes are passed into the spiral winding C1 and the spiral winding C2 to realize the adjustment of the air gap magnetic field, and then adjust the different orders. The harmonic amplitude of the second order;

Step 5, by performing Fourier harmonic analysis on the air-gap magnetic densities in the circumferential and linear directions before and after modulation, the feasibility of the above modulation principle is verified, and the thrust density and positioning accuracy of the magnetic lead screw are verified.

The present invention has the following benefit effects:

1. In the present invention, the multi-harmonic coordinated modulation of the helical permanent magnet magnetic field is realized through the spatial configuration of the magnetic modulation module and the permanent magnet, thereby improving the thrust density;

2. In the present invention, the helical winding is wound in the magnetic adjustment module, so that the air gap magnetic field of the magnetic lead screw can be adjusted, thereby improving the positioning accuracy;

3. The present invention significantly improves the thrust density and positioning accuracy while realizing the multi-harmonic coordinated modulation of the mixed magnetic source, and places the permanent body between the magnetic modulation modules to reduce the magnetic flux leakage between the poles;

To sum up, the hybrid magnetic source magnetic screw with high positioning accuracy of the present invention realizes torque-thrust conversion by three-dimensional helical magnetic transmission, which not only satisfies the magnetic field modulation in the axial linear direction, but also satisfies the magnetic field modulation in the radial and circumferential direction, and Compared with the traditional linear actuator, the thrust and torque density can be significantly improved; and compared with the traditional magnetic screw, the structure adopts the helical magnetic field modulation, and the excitation winding is wound in the magnetic control module to ensure high force. At the same time of energy density transmission, the positioning accuracy is further improved, which is especially suitable for aerospace, high-end machine tools and other fields.

Description of drawings

Fig. 1 is the structural representation of the present invention;

2 is a radial and axial cross-sectional view of the structure of the present invention; (a) is a radial cross-sectional view; (b) is an axial cross-sectional view;

3 is a schematic diagram of the positioning accuracy adjustment of the present invention; (a) is a schematic diagram of the positioning accuracy; (b) is the adjustable range of thrust;

Fig. 4 is the magnetic field distribution schematic diagram of the present invention; (a) is the magnetic pole facing position; (b) is the thrust adjustable position;

Fig. 5 is the air gap magnetic density harmonic spectrum analysis diagram of the present invention;

Fig. 6 is the adjustable range of thrust of the present invention;

In the picture: 1. Magnetic nut, 2. Magnetic screw, A1, Magnetic nut spiral magnet 1, A2, Magnetic nut spiral magnet 2, B1, Magnetic nut magnetic adjustment module, A3, Magnetic screw spiral magnet 1, A4, Magnetic Screw helical magnet 2, B2, magnetic screw magnetization module, C1, helical winding 1, C2, helical winding 2.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. In the description of the present invention, it should be understood that the terms "center", "portrait", "horizontal", "top", "bottom", "front", "rear", "left", "right", " The orientation or positional relationship indicated by vertical, horizontal, top, bottom, inner, outer, etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and The description is simplified rather than indicating or implying that the device or element referred to must have a particular orientation, be constructed and operate in a particular orientation, and therefore should not be construed as limiting the invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

The multi-harmonic coordinated modulation design of a mixed magnetic source magnetic lead screw with high positioning accuracy of the present invention is divided into the following steps:

Step 1, in the magnetic nut (1), the leads of the helical permanent magnet A1, the helical permanent magnet A2, and the helical magnetic adjustment module B1 are all λ, to ensure that in the magnetic screw rod (2), the helical permanent magnet A3 , The lead lengths of the helical permanent magnet A4, the helical magnetic modulation module B2, the helical winding C1, and the helical winding C2 are kept the same;

Step 2, while ensuring that the length of the helical lead λ is consistent, it is also necessary to ensure that the axial lengths of the helical permanent magnet A1, the helical permanent magnet A2, the helical permanent magnet A3, and the helical permanent magnet A4 are all 1 _μm , The axial lengths of the helical magnetic adjustment module B2 and the spiral magnetic adjustment module B1 are both l _t . The width of the modulating tooth is l _r , which satisfies the multi-harmonic coordinated modulation mechanism of the helical magnetic field;

Step 3: Under the condition that the multi-harmonic coordinated modulation mechanism of the helical magnetic field is satisfied, the linear direction and the circumferential direction of the magnetic nut (1) and the magnetic screw (2) are cross-sectioned. By extracting the air-gap magnetic density, the 1st, 3rd, and 5th order axial harmonic magnetic fields can be obtained; in the same way, by extracting the circular air-gap magnetic field within 2π of a circle, the 1st, 3rd, and 5th orders of the same order can be obtained. sub-circular harmonic magnetic field, thus satisfying both the modulation mechanism in the linear direction and the modulation mechanism in the circular direction;

Step 4: In the "E-type" slot of the helical magnetic adjustment module B2 of the magnetic screw rod (2), two sets of helical windings are wound, namely the helical winding C1 and the helical winding C2. Currents of different directions and amplitudes are passed into the winding C1 and the spiral winding C2 to realize the adjustment of the air-gap magnetic field, and then adjust the harmonic amplitudes of different orders;

Step 5, by performing Fourier harmonic analysis on the air-gap magnetic densities in the circumferential and linear directions before and after modulation, the feasibility of the above modulation principle is verified, and the thrust density and positioning accuracy of the magnetic lead screw are verified.

The magnetization directions of the above-mentioned helical permanent magnets A1 and A2 are directed to the helical magnetization modulating module B1, and the magnetizing directions of the helical permanent magnets A3 and A4 are directed to the helical magnetization modulating module B2. , all based on the principle of minimum reluctance, the helical permanent magnet magnetic field is drawn out through the magnetic modulation module.

In the above-mentioned magnetic screw rod (2), the leads of the helical permanent magnet A3, the helical permanent magnet A4, the helical magnetic adjustment module B2, the helical winding C1, and the helical winding C2 are all λ, ensuring that the helical permanent magnet A3, the helical The axial length of the permanent magnet A4 is the same, then the axial length of the helical permanent magnet A3 and the helical permanent magnet A4 is l _pm =λ/2-l _t , where l _t is the axial length of the magnetic adjustment module B2. The modulation tooth width of the magnetic module B2 is l _r =(l _{t -2l a} )/3, and the length of la is the width of the helical grooves of the helical winding C1 and the helical winding C2.

As shown in FIG. 1 , the present invention discloses a high positioning precision hybrid magnetic source magnetic lead screw and a method for its multi-harmonic coordinated modulation mechanism. The magnetic nut (1) is composed of a helical permanent magnet A1 and a helical permanent magnet A2. , constituted by a spiral magnetic adjustment module B1, and the magnetization directions of the spiral permanent magnet A1 and the spiral permanent magnet A2 point to the spiral magnetic adjustment module B1;

The magnetic screw rod (1) is composed of a helical permanent magnet A3, a helical permanent magnet A4, a helical magnetic adjustment module B2, a helical winding C1, and a helical winding C2, wherein the magnetization of the helical permanent magnet A3 and the helical permanent magnet A4 The direction points to the helical magnetic modulation module B2; the spiral winding C1 and the spiral winding C2 are wound in the modulation teeth of the magnetic modulation module B2. Air gap magnetic field adjustment;

As shown in FIG. 2 , the structure of the present invention is sectioned from the axial direction and the radial direction, and the 1st, 3rd, and 5th order axial harmonic magnetic fields can be obtained in the linear air gap flux density within the axial lead λ. In the same way, in the magnetic density of the circular air gap within 2π of the circumference, the 1st, 3rd, and 5th order circular harmonic magnetic fields of the same order can also be obtained, which can satisfy both the modulation mechanism in the linear direction and the modulation mechanism in the circular direction. , realizing the coordinated modulation of multiple harmonics;

As shown in Figure 3, in the modulation module B2, the "E-type" modulation tooth design is adopted. At the same time, in the "E-type" structure, the spiral winding C1 and the spiral winding C2 are wound to realize the adjustment of the air gap magnetic field, and then Realize the thrust adjustment of the fixed working point and improve the positioning accuracy;

As shown in Figure 4, by adjusting parameters such as the axial length l _pm of the helical permanent magnet, the axial length l _t of the helical magnetic modulation module, and the width l _r of the modulation teeth of the helical magnetic modulation module, the permanent magnetic The spatial parallel optimization of the magnetic field and the excitation magnetic field reduces the magnetic field coupling of the hybrid magnetic source as much as possible;

As shown in Figure 5, due to the use of the helical modulation structure, compared with the single modulation effect of the traditional helical magnetic screw, the 3rd and 5th harmonic orders are introduced. The direction and amplitude are adjusted to adjust the amplitude of the harmonics, thereby realizing the adjustment of the thrust range of the fixed working point and improving the positioning accuracy of the magnetic screw, as shown in Figure 6.

Claims (7)

1. A high-positioning-precision mixed magnetic source magnetic force lead screw is characterized by comprising a magnetic nut (1) and a magnetic lead screw (2) from outside to inside in sequence, wherein the magnetic nut and the magnetic lead screw are coaxially arranged; an air gap is formed between the magnetic nut (1) and the magnetic screw rod (2), and the length of the air gap is selected according to the size and the requirement of the magnetic screw rod;

the magnetic nut (1) is formed by a unit consisting of an axially magnetized spiral permanent magnet A1, a spiral magnetism regulating module B1 and a spiral permanent magnet A2, and a plurality of units are sequentially arranged;

the magnetic lead screw (2) is composed of a unit consisting of a spiral permanent magnet A3 magnetized axially, a spiral permanent magnet A4, a spiral magnetism adjusting module B2, a spiral winding C1 and a spiral winding C2, wherein the units are sequentially arranged to form the spiral magnetism adjusting module, and the spiral winding C1 and the spiral winding C2 are wound on the B2, wherein the current directions of the spiral winding C1 and the spiral winding C2 are opposite, when the thrust density of the mixed magnetic source magnetic lead screw is increased at a fixed working point, the amplitude of the spiral winding C1 is a positive value, and the amplitude of the spiral winding C2 is a negative value, and similarly, when the thrust density of the mixed magnetic source magnetic lead screw is decreased at the fixed working point, the amplitude of the spiral winding C1 is a negative value, and the amplitude of the spiral winding C2 is a positive value, and the magnetic field adjustment of the mixed magnetic source magnetic lead screw is realized by changing the amplitudes and the directions of the currents of the spiral winding C1 and the spiral winding C2;

in the magnetic nut (1), after passing through a spiral magnetism adjusting module B1, the permanent magnetic fields generated by the spiral permanent magnet A1 and the spiral permanent magnet A2 respectively generate odd harmonic amplitudes of 1 time, 3 times and 5 times in the axial direction and the circumferential direction; similarly, in the magnetic screw rod (2), after passing through the spiral magnetism adjusting module B2, the permanent magnetic fields generated by the spiral permanent magnet A3 and the spiral permanent magnet A4 generate harmonic orders the same as those of the magnetic nut (1), and the harmonic amplitudes are adjusted by adjusting the amplitudes and directions of currents in the spiral winding C1 and the spiral winding C2, so that multi-harmonic cooperative modulation of the magnetic nut (1) and the magnetic screw rod (2) is realized;

the magnetizing directions of the spiral permanent magnet A1 and the spiral permanent magnet A2 point to the spiral magnetism regulating module B1, and the magnetizing directions of the spiral permanent magnet A3 and the spiral permanent magnet A4 point to the spiral magnetism regulating module B2.

2. The high-positioning-precision hybrid magnetic source magnetic screw rod as claimed in claim 1, wherein in the magnetic nut (1), the lead of each of the spiral permanent magnet A1, the spiral permanent magnet A2 and the spiral magnetism adjusting module B1 is λ, so that the axial lengths of the spiral permanent magnet A1 and the spiral permanent magnet A2 are consistent, and the axial lengths of the spiral permanent magnet A1 and the spiral permanent magnet A2 are l_pm＝λ/2-l_tWherein l is_tIs the axial length of the magnetic tuning module B1.

3. The high-positioning-precision hybrid magnetic source magnetic screw rod according to claim 1, wherein in the magnetic screw rod (2), the lead of each of the spiral permanent magnet A3, the spiral permanent magnet A4, the spiral magnetism adjusting module B2, the spiral winding C1 and the spiral winding C2 is lambda, so that the axial lengths of the spiral permanent magnet A3 and the spiral permanent magnet A4 are consistent, and the axial lengths of the spiral permanent magnet A3 and the spiral permanent magnet A4 are l_pm＝λ/2-l_tWherein l is_tFor the axial length of the magnetic regulating module B2, the width l of the modulation teeth of the magnetic regulating module B2_r＝(l_t-2l_a)/3，l_aIs the spiral slot width of the spiral winding C1, the spiral winding C2.

4. The high-positioning-accuracy hybrid magnetic source magnetic screw rod as claimed in claim 1, wherein the shapes of the spiral magnetic adjustment module B1 and the spiral magnetic adjustment module B2 are designed to be an "E-shaped" structure.

5. A multi-harmonic cooperative modulation design method of the high positioning precision hybrid magnetic source magnetic screw as claimed in claim 1,

the method is characterized by comprising the following steps:

step 1, in a magnetic nut (1), all the lead lengths of a spiral permanent magnet A1, a spiral permanent magnet A2 and a spiral magnetism regulating module B1 are lambda, so that the lead lengths of the spiral permanent magnet A3, the spiral permanent magnet A4, a spiral magnetism regulating module B2, a spiral winding C1 and a spiral winding C2 in a magnetic lead screw (2) are kept consistent;

step 2, under the condition of ensuring the consistent spiral lead lambda length, ensuring that the axial lengths of the spiral permanent magnet A1, the spiral permanent magnet A2, the spiral permanent magnet A3 and the spiral permanent magnet A4 are all l_pmThe axial lengths of the spiral magnetic adjusting module B2 and the spiral magnetic adjusting module B1 are l_tThe shapes of the spiral magnetic regulating module B1 and the spiral magnetic regulating module B2 are designed into an E-shaped structure, and the width of the modulation teeth of the E-shaped structure in the modulation module is l_rThe multi-harmonic cooperative modulation mechanism of the spiral magnetic field is met;

step 3, under the condition of meeting the multi-harmonic cooperative modulation mechanism of the spiral magnetic field, the sections of the magnetic nut (1) and the magnetic screw rod (2) in the linear direction and the circumferential direction are cut, and the axial harmonic magnetic fields of 1, 3 and 5 times can be obtained by extracting the linear air gap flux density in one axial lead lambda; in the same way, the circumferential air gap flux density in one circumference 2 pi is extracted, so that 1, 3 and 5 circumferential harmonic magnetic fields with the same order can be obtained, and the modulation mechanism in the linear direction and the circumferential direction are met;

step 4, winding two groups of spiral windings, namely a spiral winding C1 and a spiral winding C2, in an E-shaped groove of a spiral magnetism adjusting module B2 of the magnetic screw rod (2), wherein when the mixed magnetic source magnetic screw rod improves thrust density at a fixed working point, the amplitude of the spiral winding C1 is a positive value, and the amplitude of the spiral winding C2 is a negative value; on the contrary, when the thrust density of the magnetic screw with the mixed magnetic source is reduced at a fixed working point, the amplitude of the spiral winding C1 is a negative value, and the amplitude of the spiral winding C2 is a positive value, and currents with different directions and amplitudes are introduced into the spiral winding C1 and the spiral winding C2 according to the actual operation working condition, so that the adjustment of an air gap magnetic field is realized, and further, the harmonic amplitudes of different orders are adjusted;

and 5, carrying out Fourier harmonic analysis on the air gap flux densities in the circumferential direction and the linear direction before and after modulation, verifying the feasibility of the modulation principle, and verifying the thrust density and the positioning accuracy of the magnetic screw rod.

6. The multi-harmonic cooperative modulation design method of the high-positioning-precision hybrid magnetic source magnetic screw rod as claimed in claim 5, wherein the magnetizing directions of the spiral permanent magnet A1 and the spiral permanent magnet A2 point to the spiral magnetization adjusting module B1, and the magnetizing directions of the spiral permanent magnet A3 and the spiral permanent magnet A4 point to the spiral magnetization adjusting module B2, and the spiral permanent magnetic field is led out through the magnetization adjusting module according to the principle of minimum magnetic resistance in both matching modes.

7. The multi-harmonic cooperative modulation design method of the high-positioning-precision hybrid magnetic source magnetic screw rod according to claim 5, wherein in the magnetic screw rod (2), the leads of the spiral permanent magnet A3, the spiral permanent magnet A4, the spiral magnetism adjusting module B2, the spiral winding C1 and the spiral winding C2 are all lambda, and the axial lengths of the spiral permanent magnet A3 and the spiral permanent magnet A4 are ensured to be consistent, so that the axial lengths of the spiral permanent magnet A3 and the spiral permanent magnet A4 are l_pm＝λ/2-l_tWherein l is_tFor the axial length of the magnetic regulating module B2, the width l of the modulation teeth of the magnetic regulating module B2_r＝(l_t-2l_a)/3，l_aIs the spiral slot width of the spiral winding C1, the spiral winding C2.

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