Segmented double-Halbach magnetic field modulation type magnetic lead screw

Abstract

The invention provides a segmented double-Halbach magnetic field modulation type magnetic lead screw, an inner stator permanent magnet is of a Halbach magnetic flux gathering structure formed by splicing different segmented permanent magnet rings in four magnet magnetizing directions, an outer rotor permanent magnet is in a spiral shape, eight rows of frame bodies are arranged in the spiral shape, one segmented permanent magnet is embedded in each frame body, and the outer rotor permanent magnet is of a magnetic flux gathering structure. The segmented permanent magnets in the eight rows of frame bodies are arranged in two modes and distributed alternately, the first mode of arrangement is magnetizing towards the outer portion of the circle center, magnetizing towards the lower portion of the Z axis and magnetizing towards the upper portion of the Z axis, and the second mode of arrangement is magnetizing towards the inner portion of the circle center, magnetizing towards the lower portion of the Z axis and magnetizing towards the upper portion of the Z axis. And the segmented permanent magnets in two arrangements are sequentially and alternately distributed and spliced to form a Halbach magnetic flux gathering structure. Halbach arrangement is adopted on the external rotor, the manufacturing cost and difficulty are reduced, the thrust and torque performance is improved on the original basis, and a key effect is achieved in low-speed, high-thrust and long-distance application.

Description

Technical Field

[0001] This invention belongs to the technical field of wave power generation new energy, specifically relating to a segmented dual Halbach magnetic field modulation magnetic screw. Background Technology

[0002] Wave energy has attracted much attention due to its enormous potential and predictability. Unlike the intermittent nature and weather-dependent nature of solar or wind energy, wave energy provides a more stable and continuous energy source. However, due to the dynamic characteristics of ocean waves and the marine environment, developing high-performance and cost-effective wave energy conversion systems remains a significant challenge. Traditional methods of utilizing wave energy employ electromechanical actuators, which offer advantages such as simple manufacturing, small size, and good dynamic performance. The transmission structures of electromechanical actuators mainly include mechanical ball screws and planetary gears. However, electromechanical actuators inevitably face problems such as mechanical wear and jamming. Magnetic screw linear actuators (MSLAs) achieve non-contact transmission through permanent magnet force, effectively avoiding the defects of traditional transmission structures such as high mechanical wear, low reliability, and insufficient dynamic performance while ensuring high thrust density. In recent years, with the development of magnetic drive technology, some scholars have proposed using magnetic screw structures as speed-increasing devices to convert low-speed linear motion into high-speed rotary motion.

[0003] The magnetic lead screw structure employs helical magnetic coupling transmission, achieving energy transfer through non-mechanical contact magnetic field coupling. This avoids problems such as mechanical wear, jamming, and insufficient overload capacity, reduces mechanical noise, improves operational reliability, and enables the mutual conversion between "torque-thrust" and "angle-displacement," making it suitable for applications with high requirements for reliability and force energy density. The magnetic lead screw consists of a magnetic nut (rotor) and a magnetic lead screw (mover), and its structure is similar to that of a traditional mechanical lead screw. However, the design of the magnetic lead screw structure requires that both the internal and external permanent magnet materials be helical, which increases the difficulty and cost of manufacturing these permanent magnet materials.

[0004] Patent CN202311849100.7 proposes a magnetic screw power generation device and its structural optimization method. By adding a Halbach arrangement to the internal stator magnet, the processing difficulty and cost can be reduced, but its performance in terms of thrust and other aspects is not good. Summary of the Invention

[0005] 1. The technical problem to be solved: Improve the performance of magnetic lead screws.

[0006] 2. Technical Solution: To address the above problems, this invention provides a segmented dual Halbach magnetic field modulation magnetic lead screw, comprising, from the inside out, an inner stator permanent magnet, a rotor helical adjustment ring, and an outer rotor permanent magnet, all coaxially arranged. The inner stator permanent magnet is a ring-shaped permanent magnet, and its structure is a Halbach flux-concentrating structure composed of four types of permanent magnets with different magnetization directions, arranged in a circular pattern. With the axis of the inner stator permanent magnet as the Z-axis, the magnetization directions of the four magnets are: magnetizing towards the center of the circle. The outer rotor permanent magnet is helical, with eight rows of frames arranged in the helical shape. Each frame contains a segmented permanent magnet. The segmented permanent magnets in the eight rows of frames are arranged in two ways, alternating between the two arrangements. The first arrangement is a Halbach flux-forming structure formed by alternating segments of permanent magnets that are magnetized outward from the center, downward along the Z-axis, and upward along the Z-axis. The second arrangement is a Halbach flux-forming structure formed by alternating segments of permanent magnets that are magnetized inward from the center, downward along the Z-axis, and upward along the Z-axis.

[0007] The moving helical magnetic adjustment ring includes a helical magnetically conductive spiral ring made of ferromagnetic material, with each pole pair spaced apart by non-magnetic metal, and the magnetically conductive spiral ring and non-magnetic metal are alternately arranged.

[0008] The sum of the number of pole pairs of the outer rotor permanent magnet and the number of pole pairs of the inner stator permanent magnet is equal to the number of pole pairs of the mover helical modulation ring. 。

[0009] The moving rotor helical adjusting ring is separated from the inner stator and outer rotor by an air gap.

[0010] The segmented permanent magnets are manufactured using particle deposition melting technology. The particle deposition melting technology is as follows: magnetic powder and plastic particles are mixed to manufacture permanent magnets. The magnetic powder is MQP-S magnetic spherical particles. Then, the MQP-S magnetic spherical particles and PA-12 binder particles are heated and spirally extruded. The extruded paste is deposited and melted into a paste, and then 3D printed to form segmented embedded permanent magnets.

[0011] 3. Beneficial effects: This invention employs a quasi-Harbach arrangement on the external rotor and uses a limiter for embedded segmented design, which not only greatly reduces manufacturing costs and difficulty, but also significantly improves thrust and torque performance on the original basis. Compared with ordinary magnetic screws, it has a higher transmission ratio, making it play a key role in low-speed, high-thrust, and long-distance applications. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of a segmented double Halbach magnetic field modulated magnetic lead screw structure.

[0013] Figure 2 This is a cross-sectional view of the external rotor permanent magnet.

[0014] Figure 3 This is a schematic diagram of the Halbach arrangement structure of the external rotor permanent magnet, where (a) is the existing external rotor permanent magnet; and (b) is the Halbach arrangement structure.

[0015] Figure 4 These are schematic diagrams of three magnetic lead screw structures, where (a) is a common MSLA structure; (b) is a common segmented mechanism; and (c) is the segmented double Halbach magnetic field modulation magnetic lead screw structure of the present invention.

[0016] Figure 5 These are three types of magnetic screw thrust and rotor torque performance diagrams; where (a) is the thrust and (b) is the torque.

[0017] Explanation of reference numerals in the attached diagram: 1. Inner stator permanent magnet; 2. Mover helical magnetic adjustment ring; 3. Segmented permanent magnet; 301. Magnetizing towards the outside of the center; 302. Magnetizing towards the inside of the center; 303. Magnetizing downwards along the Z-axis; 304. Magnetizing upwards along the Z-axis; 4. Outer rotor permanent magnet; 5. Magnetic conductive helical ring; 6. First arrangement; 7. Second arrangement. Detailed Implementation

[0018] The present invention will now be described in detail with reference to the accompanying drawings.

[0019] like Figure 1 As shown, a segmented double Halbach magnetic field modulation magnetic lead screw consists of an inner stator permanent magnet 1, a mover helical magnetic adjustment ring 2, and an outer rotor permanent magnet 4, arranged coaxially from the inside out. The inner stator permanent magnet 1 is a ring-shaped permanent magnet. The inner stator permanent magnet 1 is a Halbach flux-concentrating structure composed of four types of convex toothed permanent magnet rings with different magnetization directions. With the axis of the inner stator permanent magnet 1 as the Z-axis, the magnetization directions of the four magnets are: magnetization towards the inside of the circle 302, magnetization towards the outside of the circle 301, magnetization downward along the Z-axis 303, and magnetization upward along the Z-axis 304.

[0020] The innovation of this invention lies in: Figures 1-3As shown, the outer rotor permanent magnet 4 is spiral-shaped, with 8 rows of frames in the spiral. Each frame contains a segmented permanent magnet 3. The segmented permanent magnets in the 8 rows of frames are arranged in two ways, with the two arrangements alternating. The first arrangement 6 is a Halbach flux-gathering structure formed by alternatingly distributing and splicing the segmented permanent magnets 3 with magnetization 301 towards the outside of the center, magnetization 303 downward along the Z-axis, and magnetization 304 upward along the Z-axis. The second arrangement 7 is a Halbach flux-gathering structure formed by alternatingly distributing and splicing the segmented permanent magnets 3 with magnetization 302 towards the inside of the center, magnetization 303 downward along the Z-axis, and magnetization 304 upward along the Z-axis.

[0021] The segmented dual Halbach field-modulated magnetic screw motor modulates the magnetic field generated by the annular permanent magnet into a helical magnetic field through a moving helical adjustment ring, which then matches the helical magnetic field of the shared rotor permanent magnet to achieve maximum output torque. Wave thrust drives the helical adjustment ring in linear motion, and the linear moving part then drives the shared rotor in rotational motion through the helical magnetic field, ultimately utilizing the motor stator windings to output power.

[0022] exist Figures 1 to 3 In the diagram, red indicates magnetization towards the center (302), blue indicates magnetization towards the outside (301), yellow indicates magnetization downwards along the Z-axis (303), and green indicates magnetization upwards along the Z-axis (304).

[0023] The external rotor permanent magnet of this invention adopts a helical structure, with axial and radial magnets arranged in a combination, and the radial magnets sandwiched between the axial magnets to form a Halbach arrangement. The Halbach permanent magnet arrangement can also weaken the magnetic flux of the yoke, providing a magnetic shielding effect. This can greatly reduce the magnetic leakage phenomenon between the poles of the double Halbach magnetic screw, and also reduce the thickness of the internal stator core.

[0024] This invention retains the advantage that the conventional segmented rotor section can also serve as a motor rotor, thereby reducing the size of the motor and significantly lowering its manufacturing cost.

[0025] The performance of double Halbach, ordinary segmented, and MSLA (hereinafter referred to as MSLA) structures is compared. The structures are as follows: Figure 4 As shown. The rotor torque and magnetic ring thrust of the three structures are compared, keeping the dimensions of the effective parts of the structures consistent. The results are as follows. Figure 5As shown in Table 1, the thrust amplitude of the dual Halbach design is 2.28 kN, which is 204.66% higher than that of the conventional segmented design and 14.25% higher than that of the MSLA design, demonstrating a significant improvement in thrust performance. The thrust-to-torque ratio on the dual Halbach adjusting ring is 761, while the torque-to-torque ratio for the MSLA is 250, approximately three times that of the MSLA. The thrust amplitude of the dual Halbach design is 2.28 kN, which is 204.66% higher than that of the conventional segmented design and 14.25% higher than that of the MSLA design, demonstrating a significant improvement in thrust performance. The thrust-to-torque ratio on the dual Halbach adjusting ring is 761, while the torque-to-torque ratio for the MLSA is 250, approximately three times that of the MLSA.

[0026] Table 1 Structural parameters of the magnetic field modulated magnetic lead screw multilayer composite motor When used with a motor, the rotor and linear mover move synchronously; that is, when the linear mover moves one pole pitch, the rotor rotates one revolution. The maximum output power of the motor is achieved when the linear speed and rotational speed match. The permanent magnet motor and the magnetic field modulated lead screw structure are integrated, enabling the conversion of low-speed, high-thrust (wave-like linear motion) on the mover side into high-speed, low-torque (high-speed generator) on the rotor side. By segmenting the permanent magnet and embedding it with non-magnetic materials, the manufacturing and fixing difficulty is reduced. Since the magnetic field modulated lead screw and motor share a single outer rotor permanent magnet, the amount of permanent magnet material used is reduced, and the size of the composite motor device is minimized. Through the mover adjusting ring, the magnetic field modulated lead screw motor achieves shared rotor speed-up operation.

[0027] In one embodiment, the moving screw tuning ring 2 includes a helical magnetically conductive spiral ring 5, which is made of ferromagnetic material. Each pole pair is filled with non-magnetic metal. The magnetically conductive spiral ring 5 and the non-magnetic metal are alternately arranged to prevent the magnetic field between adjacent pole pairs of the moving screw tuning ring 2 from penetrating. The outer surface of the magnetically conductive spiral ring 5 is wrapped with a damping winding.

[0028] The moving helical magnetic ring 2 undergoes axial low-speed, high-thrust linear reciprocating motion under the action of wave energy. The low-speed, high-thrust motion of the moving helical magnetic ring 2 modulates the enhanced static permanent magnet magnetic field into a helical magnetic field. The helical magnetic field drives the segmented permanent magnet 3 to rotate, causing the moving helical magnetic ring to magnetically couple with the segmented permanent magnet 3 inside the outer rotor permanent magnet 4. The alternating permanent magnet magnetic field generated by the rotation of the segmented permanent magnet 3 induces electrical energy in the windings of the rotating motor.

[0029] In one embodiment, the sum of the number of pole pairs of the outer rotor permanent magnet and the number of pole pairs of the inner stator permanent magnet is equal to the number of pole pairs of the mover helical modulation ring.

[0030] In one embodiment, the moving rotor helical adjusting ring is separated from the inner stator and outer rotor by an air gap, thus avoiding mechanical contact.

[0031] In one embodiment, the segmented permanent magnet is manufactured using a particle deposition melting technique. The particle deposition melting technique involves mixing magnetic powder with plastic particles to manufacture the permanent magnet. The magnetic powder is selected as MQP-S magnetic spherical particles. Then, the MQP-S magnetic spherical particles and PA-12 adhesive particles are heated and spirally extruded. The extruded paste is deposited and melted with a paste agent, and then 3D printed to form a segmented embedded permanent magnet.

[0032] The permanent magnet in this invention is made of rare earth material N38NdFe-B, and the back iron of the outer rotor permanent magnet is made of DW470-50.

[0033] This invention provides a segmented dual Halbach magnetic field modulated magnetic lead screw, which has significant advantages over general magnetic lead screws and magnetic field modulated structures. It has lower processing difficulty and cost, increases thrust by 14.25% compared to ordinary MSLA, and has a torque-to-torque ratio of 761, which is much higher than the comparative structures.

Claims

1. A segmented dual Halbach magnetic field modulation magnetic lead screw, comprising, from the inside out, an inner stator permanent magnet, a rotor helical adjustment ring, and an outer rotor permanent magnet, all coaxially arranged. The inner stator permanent magnet is a ring-shaped permanent magnet, and is a Halbach flux-concentrating structure composed of four types of permanent magnets with different magnetization directions arranged in a circular ring. With the axis of the inner stator permanent magnet as the Z-axis, the magnetization directions of the four types of magnets are: magnetizing towards the center, magnetizing towards the outside, magnetizing downwards along the Z-axis, and magnetizing upwards along the Z-axis. Its characteristics are: The outer rotor permanent magnet is helical, and the helical shape has 8 rows of frames. Each frame contains a segmented permanent magnet. The segmented permanent magnets in the 8 rows of frames are arranged in two ways, with the two arrangements alternating. The first arrangement is a Halbach flux-forming structure in which the segmented permanent magnets magnetize outward from the center, downward along the Z-axis, and upward along the Z-axis, respectively. The second arrangement is a Halbach flux-forming structure in which the segmented permanent magnets magnetize inward from the center, downward along the Z-axis, and upward along the Z-axis, respectively, respectively.

2. The segmented double Halbach magnetic field modulated magnetic lead screw as described in claim 1, characterized in that: The moving helical magnetic adjustment ring includes a helical magnetically conductive spiral ring made of ferromagnetic material, with each pole pair spaced apart by non-magnetic metal, and the magnetically conductive spiral ring and non-magnetic metal are alternately arranged.

3. The segmented double Halbach magnetic field modulated magnetic lead screw as described in claim 1, characterized in that: The sum of the number of pole pairs of the outer rotor permanent magnet and the number of pole pairs of the inner stator permanent magnet is equal to the number of pole pairs of the mover helical modulation ring. 。 4. The segmented double Halbach magnetic field modulated magnetic lead screw as described in claim 1, characterized in that: The moving rotor helical adjusting ring is separated from the inner stator permanent magnet and the outer rotor permanent magnet by an air gap.

5. The segmented double Halbach magnetic field modulated magnetic screw as described in any one of claims 1-4, characterized in that: The segmented permanent magnets are manufactured using particle deposition melting technology. The particle deposition melting technology is as follows: magnetic powder and plastic particles are mixed to manufacture permanent magnets. The magnetic powder is MQP-S magnetic spherical particles. Then, the MQP-S magnetic spherical particles and PA-12 binder particles are heated and spirally extruded. The extruded paste is deposited and melted into a paste, and then 3D printed to form segmented embedded permanent magnets.

6. The segmented double Halbach magnetic field modulated magnetic screw as described in any one of claims 1-4, characterized in that: The permanent magnets are all made of rare earth material N38NdFe-B, and the back iron of the outer rotor permanent magnet is DW470-50.

Images