Non-equal-height double-coil electromagnetic actuator

Abstract

This invention proposes a non-uniform-height dual-coil electromagnetic actuation device, belonging to the aerospace field. It solves the problems of severe magnetic leakage, inability to suppress armature reaction, and low thrust density in existing electromagnetic actuators. It includes a stator and a mover. The stator comprises an upper magnetic structure, an outer magnetic structure, a lower magnetic structure, and an inner magnetic structure. The outer magnetic structure includes an outer lower radial magnetic ring, an outer central axial magnetic ring, an outer upper radial magnetic ring, and an outer yoke. The outer upper radial magnetic ring is installed on the upper inner side of the outer yoke. The outer central axial magnetic ring is installed on the middle inner side of the outer yoke and located below the outer upper radial magnetic ring. The outer lower radial magnetic ring is installed on the lower inner side of the outer yoke and located below the outer central axial magnetic ring. The mover includes a mover coil frame, an upper coil, and a lower coil. The mover coil frame is disposed within an air gap, and annular grooves are formed on both the upper and lower outer sides of the mover coil frame. It is mainly used for on-orbit servicing of spacecraft.

Description

Technical Field

[0001] This invention belongs to the field of aerospace, and in particular relates to a non-uniform height dual-coil electromagnetic actuation device. Background Technology

[0002] With the development of aerospace technology and the continuous exploration of space, various types of spacecraft are launched into space to complete their respective scientific missions. Currently, a large number of spacecraft are operating in orbit, while some have reached the end of their service life, exhausted their fuel, or suffered component failure, becoming space debris. However, through space service measures such as on-orbit maintenance or replacement of components, refueling, and changing service orbits, the service life of spacecraft can be extended, and the application cost of spacecraft can be reduced.

[0003] For on-orbit servicing missions, the servicing spacecraft needs to rendezvous and dock with the target spacecraft before refueling and maintenance services can be performed. After completing the servicing mission, the servicing spacecraft needs to separate the target spacecraft again and return it to its working orbit. This process requires a reusable separation device that can adjust the separation speed for different types of spacecraft, and electromagnetic actuation devices play a crucial role in this process.

[0004] Currently, existing electromagnetic actuators, such as the Chinese patent with publication number CN113572334A, disclose a dual-magnetic-circuit electromagnetic actuator with a compensating magnet. It achieves permanent magnet flux shunting by forming front and rear dual permanent magnet branch circuits on a single-layer magnetic pole structure and increases the magnetomotive force and air gap magnetic field strength by using end compensating magnets. However, it has problems such as large end leakage magnetic field, armature reaction caused by a single coil, no effective suppression measures for armature reaction, and small initial thrust due to the small magnetic field strength at the bottom of the air gap.

[0005] Chinese patent CN113443176A discloses an electromagnetic actuator for a nanosatellite deployer, which utilizes multiple magnetic rings connected in series to form a single closed permanent magnet circuit to increase the magnetic field strength of the inner and outer air gaps. This invention has two air gaps, which, while enhancing the actuator's speed range, also causes more severe magnetic leakage at the ends. The lack of an auxiliary permanent magnet at the bottom results in weak magnetic field strength at the bottom of the two air gaps, leading to a smaller initial thrust of the actuator.

[0006] Chinese patent CN113562203A discloses an electromagnetic actuator with a redundant air gap. It utilizes a magnetic isolation ring to create a redundant air gap and forms an auxiliary permanent magnet circuit. While this method increases the magnetic flux density of the end air gap, the coil generates a large electromagnetic field, leading to armature reaction. This invention fails to mitigate this armature reaction. Furthermore, the magnetic flux circuit formed by the lower magnetic ring arranged within the permanent magnet at the bottom of the air gap weakens the air gap magnetic field strength.

[0007] Chinese patent CN113572335A discloses a single-layer magnetic pole electromagnetic actuator with dual windings. It utilizes a guide magnetic ring to solve the problem of magnetic field cancellation caused by opposing magnetic circuits, and reduces some magnetic leakage by guiding the magnetic flux in different branches. However, the two-coil air gap still results in significant magnetic leakage. Furthermore, the radially arranged two coils cause the direction of the electromagnetic flux loop generated by the coils to be opposite to the direction of the magnetic flux loop generated by the permanent magnet, thereby reducing the magnetic flux density in the air gap.

[0008] It can be seen that existing electromagnetic actuators suffer from numerous problems, such as severe end magnetic leakage, low initial thrust, and difficulty in suppressing armature reaction. Current electromagnetic actuators use dual coils with reverse currents to generate opposing electromagnetic fields that cancel each other out, thereby suppressing armature reaction. However, existing actuators with dual coil designs have high magnetic leakage and low thrust density, resulting in similarly low energy conversion efficiency. To meet the mission requirements of various types of spacecraft after completing on-orbit servicing and then separating, electromagnetic actuators need to have the ability to suppress armature reaction, reduce the risk of demagnetization, and operate stably in orbit for extended periods, while still maintaining a certain thrust density. Summary of the Invention

[0009] In view of this, the present invention aims to propose a non-uniform height dual-coil electromagnetic actuation device to solve the problems of serious magnetic leakage, inability to suppress armature reaction and low thrust density of existing electromagnetic actuators.

[0010] To achieve the above objectives, the present invention adopts the following technical solution: a non-uniform height double-coil electromagnetic actuation device, comprising a stator and a mover, wherein the stator comprises an upper magnetic structure, an outer magnetic structure, a lower magnetic structure, and an inner magnetic structure, the outer magnetic structure comprising an outer lower radial magnetic ring, an outer central axial magnetic ring, an outer upper radial magnetic ring, and an outer yoke, the outer upper radial magnetic ring being installed on the upper inner side of the outer yoke, the outer central axial magnetic ring being installed on the middle inner side of the outer yoke and located below the outer upper radial magnetic ring, and the outer lower radial magnetic ring being installed on... The inner magnetic structure includes an inner yoke, an inner upper radial magnetic ring, an inner central axial magnetic ring, and an inner lower radial magnetic ring. The inner upper radial magnetic ring is mounted on the upper part of the inner yoke. The inner central axial magnetic ring is mounted in the middle of the inner yoke and is located below the inner upper radial magnetic ring. The inner lower radial magnetic ring is mounted on the lower part of the inner yoke and is located below the inner central axial magnetic ring. The outer upper radial magnetic ring and the inner upper radial magnetic ring have the same height. The upper radial magnetic ring is composed of an outer lower radial magnetic ring and an inner lower radial magnetic ring of the same height. The outer lower radial magnetic ring and the inner lower radial magnetic ring together form the lower radial magnetic ring. The outer central axial magnetic ring and the inner central axial magnetic ring of the same height together form the middle axial magnetic ring. The height of the upper radial magnetic ring is greater than that of the lower radial magnetic ring. The upper and lower ends of the inner magnetic yoke are respectively installed at the center of the upper and lower magnetic structures. The upper and lower ends of the outer magnetic yoke are respectively installed at the edges of the upper and lower magnetic structures. There is an air gap between the radially inner side of the outer magnetic structure and the radially outer side of the inner magnetic structure. The mover includes a mover coil frame, an upper coil, and a lower coil. The mover coil frame is set in the air gap. Annular grooves are formed on the upper and lower parts of the outer side of the mover coil frame. The upper coil and the lower coil are respectively arranged in the annular grooves on the upper and lower parts. The height of the upper coil is greater than that of the lower coil. The current flowing through the upper coil is in the opposite direction to the current flowing through the lower coil.

[0011] Furthermore, the upper magnetic structure includes an upper magnetic yoke and an upper axial magnetic ring. The upper axial magnetic ring is installed on the lower side of the upper magnetic yoke, the upper end of the inner magnetic yoke is installed at the center of the upper magnetic yoke, and the upper end of the outer magnetic yoke is installed at the edge of the upper magnetic yoke.

[0012] Furthermore, the lower magnetic structure includes a lower inner axial magnetic ring, a lower yoke, and a lower outer axial magnetic ring. The lower inner axial magnetic ring is installed on the upper radial inner side of the lower yoke, and the lower outer axial magnetic ring is installed on the upper radial outer side of the lower yoke. The lower end of the inner yoke is installed at the center of the lower yoke, and the lower end of the outer yoke is installed at the edge of the lower yoke.

[0013] Furthermore, the top plate, the linear motion base plate, the lower support rod, and the upper support rod are all multiple rods, and are evenly distributed along the circumference of the moving coil frame. One end of the lower support rod is connected to the lower part of the moving coil frame, and the other end passes through the lower magnetic structure and is connected to the linear motion base plate. One end of the upper support rod is connected to the upper part of the moving coil frame, and the other end passes through the upper magnetic structure and is connected to the top plate.

[0014] Furthermore, the lower part of the lower magnetic structure is connected to the stator frame, which includes a base and stator support rods. There are multiple stator support rods, which are evenly distributed along the circumference of the base. One end of each stator support rod is connected to the base, and the other end is connected to the lower magnetic structure. The linear motion base plate is slidably connected to the stator support rods.

[0015] Furthermore, the top plate, base, stator support rod, lower support rod, and upper support rod are all made of 2A12 hard aluminum alloy.

[0016] Furthermore, the materials of the lower inner axial magnetic ring, lower outer axial magnetic ring, outer upper radial magnetic ring, outer middle axial magnetic ring, outer lower radial magnetic ring, inner upper radial magnetic ring, inner middle axial magnetic ring, inner lower radial magnetic ring, and upper axial magnetic ring are all neodymium iron boron N35 permanent magnet materials, and the magnetization directions are as follows: front S rear N, front N rear S, inner S outer N, front S rear N, inner N outer S, inner S outer N, front N rear S, inner N outer S, front S rear N.

[0017] Furthermore, the outer yoke, inner yoke, upper yoke, and lower yoke are all made of DT4C, and the mover coil frame is made of polyimide.

[0018] Furthermore, the height of the lower radial magnetic ring is the height of the lower coil plus the distance between the upper and lower coils and the reserved coil installation height minus the height of the middle axial magnetic ring, and the height of the upper radial magnetic ring is 8-12 times the height of the lower radial magnetic ring.

[0019] Furthermore, the ratio of the height of the upper coil to the height of the lower coil is greater than or equal to 5 and less than or equal to 7, and the distance between the upper coil and the lower coil is 1.5 to 2.5 times the height of the lower coil.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention provides an electromagnetic actuation device for space on-orbit servicing, which can suppress the problem of strong armature reaction in existing electromagnetic actuators, while providing sufficient thrust density. The present invention utilizes multi-layered ring permanent magnets to form multiple closed permanent magnet circuits, and adopts a closed magnetic yoke structure to effectively reduce magnetic leakage, increase the strength of the air gap magnetic field, improve the uniformity of the air gap magnetic flux density, and reduce thrust fluctuations.

[0021] In this invention, the upper and lower coils are not at the same height, the distance between the two coils is small, and they are energized with reverse current. The electromagnetic field generated by the lower coil affects the local magnetic field of the upper coil, increasing the Ampere force on the upper coil and increasing the thrust density. Simultaneously, the lower coil generates an electromagnetic field opposite to that of the upper coil, weakening the armature reaction. In the initial stage of the movement of the upper and lower coils, the energized upper coil experiences an upward Ampere force due to the magnetic field formed by the upper radial magnetic ring. The lower coil, carrying a reverse current, also experiences an upward Ampere force due to the magnetic field formed by the lower radial magnetic ring and the magnetic field formed by the bottom axial magnetic ring. The auxiliary magnetic circuit enhances the magnetic field strength at the bottom of the air gap between the lower radial magnetic rings, increasing the initial thrust. After the upper and lower coils move upward a certain distance under the Ampere force, both coils enter the air gap between the upper radial magnetic rings. At this point, the energizing direction of the upper and lower coils remains unchanged; the upper coil still experiences an upward Ampere force, while the lower coil experiences a downward Ampere force. However, because the electromagnetic fields generated by the upper and lower coils are in opposite directions, a stronger magnetic pole is formed, causing some of the magnetic flux in the air gap to pass between the upper and lower coils. At the same time, the thinner lower coil creates a local magnetic flux loop, thereby enhancing the magnetic field strength near the upper coil and guiding more magnetic flux through the gap between the upper and lower coils. This increases the Ampere force generated by the upper coil in the air gap, and the increased Ampere force is greater than that experienced by the lower coil, thus improving the thrust density of the device. The low-height lower radial magnetic ring, the bottom axial magnetic ring, and the lower coil work together to improve the initial thrust.

[0022] This invention employs three axial magnetic rings arranged at the ends. A permanent magnet ring at the upper end directs magnetic flux from the outer magnetic structure to the inner magnetic structure, reducing magnetic leakage at the upper end. Two permanent magnet rings at the lower end, with opposite magnetization directions, form local magnetic flux loops, reducing magnetic leakage while enhancing the magnetic field strength in the bottom air gap. This invention uses multiple magnetic rings spliced ​​together to form three main magnetic flux loops. At the ends, radially magnetized permanent magnet rings, together with the outer and inner magnetic structures, form small local magnetic flux loops, reducing magnetic leakage and increasing the magnetic flux density in the air gap at the ends, thereby increasing the initial thrust.

[0023] This invention features a compact structure, small size, light weight, and a wide thrust adjustment range, meeting the current practical needs of on-orbit space services. It is used for the separation of various types of spacecraft after on-orbit maintenance, ensuring that the spacecraft separates at a predetermined speed. Attached Figure Description

[0024] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0025] Figure 1 This is a three-dimensional structural diagram of a non-uniform height dual-coil electromagnetic actuation device according to the present invention;

[0026] Figure 2 This is a schematic diagram of the magnetic circuit cross-section of an electromagnetic actuation device for space on-orbit servicing according to the present invention;

[0027] Figure 3 This is a schematic diagram of the three-dimensional structure of the moving part described in this invention;

[0028] Figure 4 This is a three-dimensional schematic diagram of the external magnetic structure described in this invention;

[0029] Figure 5 This is a three-dimensional schematic diagram of the internal magnetic structure described in this invention;

[0030] Figure 6 This is a three-dimensional schematic diagram of the upper magnetic structure described in this invention;

[0031] Figure 7 This is a three-dimensional schematic diagram of the lower magnetic structure described in this invention;

[0032] Figure 8 This is a three-dimensional schematic diagram of the stator frame described in this invention;

[0033] Figure 9 This is a schematic diagram of the magnetic circuit of the stator described in this invention.

[0034] In the picture:

[0035] 1-Top plate, 2-Upper magnetic structure, 3-Outer magnetic structure, 4-Lower magnetic structure, 5-Base, 6-Stator support rod, 7-Linear motion base plate, 8-Lower support rod, 9-Upper support rod, 10-Upper yoke, 11-Upper axial magnetic ring, 12-Inner yoke, 13-Inner upper radial magnetic ring, 14-Motor coil frame, 15-Upper coil, 16-Lower coil, 17-Inner central axial magnetic ring, 18-Inner lower radial magnetic ring, 19-Lower inner axial magnetic ring, 20-Lower yoke, 21-Lower outer axial magnetic ring, 22-Outer lower radial magnetic ring, 23-Outer central axial magnetic ring, 24-Outer upper radial magnetic ring, 25-Outer yoke. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other, and the described embodiments are only some embodiments of the present invention, not all embodiments.

[0037] See Figure 1-9This embodiment describes a non-uniform height double-coil electromagnetic actuation device, which includes a stator and a mover. The stator includes an upper magnetic structure 2, an outer magnetic structure 3, a lower magnetic structure 4, and an inner magnetic structure. The outer magnetic structure 3 includes an outer lower radial magnetic ring 22, an outer central axial magnetic ring 23, an outer upper radial magnetic ring 24, and an outer yoke 25. The outer upper radial magnetic ring 24 is installed on the upper inner side of the outer yoke 25. The outer central axial magnetic ring 23 is installed on the middle inner side of the outer yoke 25 and is located below the outer upper radial magnetic ring 24. The outer lower radial magnetic ring 22 is installed on the lower inner side of the outer yoke 25 and is located below the outer... Below the central axial magnetic ring 23, the inner magnetic structure includes an inner yoke 12, an inner upper radial magnetic ring 13, an inner central axial magnetic ring 17, and an inner lower radial magnetic ring 18. The inner upper radial magnetic ring 13 is installed on the upper part of the inner yoke 12. The inner central axial magnetic ring 17 is installed in the middle of the inner yoke 12 and is located below the inner upper radial magnetic ring 13. The inner lower radial magnetic ring 18 is installed on the lower part of the inner yoke 12 and is located below the inner central axial magnetic ring 17. The outer upper radial magnetic ring 24 has the same height as the inner upper radial magnetic ring 13. The outer upper radial magnetic ring 24 and the inner upper radial magnetic ring 13 form an upper... The upper and lower radial magnetic rings are arranged in a lower layer. The outer lower radial magnetic ring 22 and the inner lower radial magnetic ring 18 have the same height, forming the lower layer radial magnetic ring. The outer central axial magnetic ring 23 and the inner central axial magnetic ring 17 have the same height, forming the middle layer axial magnetic ring. The height of the upper layer radial magnetic ring is greater than that of the lower layer radial magnetic ring. The upper and lower ends of the inner magnetic yoke 12 are respectively bolted to the center of the upper magnetic structure 2 and the lower magnetic structure 4. The upper and lower ends of the outer magnetic yoke 25 are respectively bolted to the center of the upper magnetic structure 2 and the lower magnetic structure 4. At the edges of the upper magnetic structure 2 and the lower magnetic structure 4, there is an air gap between the radially inner side of the outer magnetic structure 3 and the radially outer side of the inner magnetic structure. The mover includes a mover coil frame 14, an upper coil 15, and a lower coil 16. The mover coil frame 14 is disposed in the air gap. Annular grooves are provided on the upper and lower parts of the outer side of the mover coil frame 14. The upper coil 15 and the lower coil 16 are respectively disposed in the annular grooves on the upper and lower parts. The height of the upper coil 15 is greater than the height of the lower coil 16. The current flowing through the upper coil 15 is in the opposite direction to the current flowing through the lower coil 16.

[0038] The upper magnetic structure 2 described in this embodiment includes an upper magnetic yoke 10 and an upper axial magnetic ring 11. The upper axial magnetic ring 11 is installed on the lower side of the upper magnetic yoke 10, the upper end of the inner magnetic yoke 12 is installed at the center of the upper magnetic yoke 10, and the upper end of the outer magnetic yoke 25 is installed at the edge of the upper magnetic yoke 10.

[0039] The lower magnetic structure 4 described in this embodiment includes a lower inner axial magnetic ring 19, a lower magnetic yoke 20, and a lower outer axial magnetic ring 21. The lower inner axial magnetic ring 19 is installed on the upper radial inner side of the lower magnetic yoke 20, and the lower outer axial magnetic ring 21 is installed on the upper radial outer side of the lower magnetic yoke 20. The lower end of the inner magnetic yoke 12 is installed at the center of the lower magnetic yoke 20, and the lower end of the outer magnetic yoke 25 is installed at the edge of the lower magnetic yoke 20.

[0040] In this embodiment, the top plate 1, the linear motion base plate 7, the lower support rod 8, and the upper support rod 9 are described. There are four lower support rods 8 and four upper support rods 9, which are evenly distributed along the circumference of the moving coil frame 14. One end of the lower support rod 8 is connected to the lower part of the moving coil frame 14, and the other end passes through the lower magnetic structure 4 and is connected to the linear motion base plate 7. One end of the upper support rod 9 is connected to the upper part of the moving coil frame 14, and the other end passes through the upper magnetic structure 2 and is connected to the top plate 1.

[0041] In this embodiment, the lower magnetic structure 4 is connected to the stator frame. The stator frame includes a base 5 and stator support rods 6. There are four stator support rods 6, which are evenly distributed along the circumference of the base 5. One end of each stator support rod 6 is connected to the base 5, and the other end is connected to the lower magnetic structure 4. The linear motion base plate 7 is slidably connected to the stator support rods 6. The mover achieves linear motion by cooperating with the stator support rods 6 through the linear motion base plate 7.

[0042] In this embodiment, the top plate 1 and the upper support rod 9 are bolted together, the upper support rod 9 and the mover coil frame 14 are threaded together, the linear motion base plate 7 and the lower support rod 8 are bolted together, the lower support rod 8 and the mover coil frame 14 are threaded together, the base 5 and the stator support rod 6 are bolted together, and the stator support rod 6 and the lower magnetic yoke 20 are threaded together.

[0043] In this embodiment, the top plate 1, base 5, stator support rod 6, lower support rod 8, and upper support rod 9 are all made of 2A12 hard aluminum alloy. The outer magnetic yoke 25, inner magnetic yoke 12, upper magnetic yoke 10, and lower magnetic yoke 20 are all made of DT4C, and the mover coil frame 14 is made of polyimide.

[0044] In this embodiment, the materials of the lower inner axial magnetic ring 19, lower outer axial magnetic ring 21, outer upper radial magnetic ring 24, outer middle axial magnetic ring 23, outer lower radial magnetic ring 22, inner upper radial magnetic ring 13, inner middle axial magnetic ring 17, inner lower radial magnetic ring 18, and upper axial magnetic ring 11 are all neodymium iron boron N35 permanent magnet materials, and the magnetization directions are as follows: front S rear N, front N rear S, inner S outer N, front S rear N, inner N outer S, inner S outer N, front N rear S, inner N outer S, front S rear N.

[0045] In this embodiment, the height of the lower radial magnetic ring is the height of the lower coil 16 plus the distance between the upper coil 15 and the lower coil 16, plus the reserved installation height of the coil 16 minus the height of the middle axial magnetic ring. The height of the upper radial magnetic ring is 8-12 times the height of the lower radial magnetic ring. The ratio of the height of the upper coil 15 to the height of the lower coil 16 is greater than or equal to 5 and less than or equal to 7. The distance between the upper coil 15 and the lower coil 16 is 1.5 to 2.5 times the height of the lower coil 16. This increases the magnetic flux density between the upper coil 15 and the lower coil 16, increases the Ampere force generated by the upper coil 15 in the closed air gap magnetic field, and improves the thrust density of the entire structure.

[0046] The working principle of this embodiment is as follows: the lower inner axial magnetic ring 19, the lower outer axial magnetic ring 21, the outer upper radial magnetic ring 24, the outer middle axial magnetic ring 23, the outer lower radial magnetic ring 22, the inner upper radial magnetic ring 13, the inner middle axial magnetic ring 17, the inner lower radial magnetic ring 18, and the upper axial magnetic ring 11 form a closed air gap and create a constant permanent magnet magnetic field in the air gap. The outer magnetic yoke 25, the upper magnetic yoke 10, the inner magnetic yoke 12, and the lower magnetic yoke 20 enclose the permanent magnet, reduce leakage magnetic field, and enhance the magnetic density of the air gap magnetic field.

[0047] The device described in this embodiment can form three main permanent magnet closed loops, as detailed below:

[0048] Permanent magnet closed loop one: The magnetic flux starts from the N pole of the inner upper radial magnetic ring 13, passes through the air gap, the S pole of the outer upper radial magnetic ring 24, the N pole of the outer upper radial magnetic ring 24, the outer magnetic yoke 25, the upper magnetic yoke 10, the inner magnetic yoke 12, and finally returns to the S pole of the inner middle radial magnetic ring.

[0049] Permanent magnet closed loop two: The magnetic flux starts from the N pole of the inner upper radial magnetic ring 13, passes through the air gap, the S pole of the outer upper radial magnetic ring 24, the N pole of the outer upper radial magnetic ring 24, the outer yoke 25, the S pole of the outer lower radial magnetic ring 22, the N pole of the outer lower radial magnetic ring 22, the air gap, the S pole of the inner lower radial magnetic ring 18, the N pole of the inner lower radial magnetic ring 18, the inner yoke 12, the N pole of the outer upper radial magnetic ring, and finally returns to the S pole of the inner upper radial magnetic ring 13.

[0050] Permanent magnet closed loop three: The magnetic flux starts from the N pole of the inner lower radial magnetic ring 18, passes sequentially through the inner magnetic yoke 12, the lower magnetic yoke 20, the outer magnetic yoke 25, the S pole of the outer lower radial magnetic ring 22, the N pole of the outer lower radial magnetic ring 22, the air gap, and finally returns to the S pole of the inner lower radial magnetic ring. The magnetic flux generated by the upper axial magnetic ring 11, the outer middle axial magnetic ring 23, the inner middle axial magnetic ring 17, the lower outer axial magnetic ring 21, and the lower inner axial magnetic ring 19 is used to improve the magnetic field distribution in the air gap.

[0051] The device described in this embodiment can also form an auxiliary magnetic circuit through the magnetic flux loop formed by the lower inner axial magnetic ring 19 and the lower outer axial magnetic ring 21. Specifically, the auxiliary magnetic circuit is as follows: the magnetic flux starts from the N pole of the lower inner axial magnetic ring 19, passes through the lower yoke 20, the S pole of the lower outer axial magnetic ring 21, the N pole of the lower outer axial magnetic ring 21, the outer lower radial magnetic ring 22, the air gap, the inner lower radial magnetic ring 18, and finally returns to the S pole of the lower inner axial magnetic ring 19.

[0052] During operation, the lower inner axial magnetic ring 19, lower outer axial magnetic ring 21, outer upper radial magnetic ring 24, outer middle axial magnetic ring 23, outer lower radial magnetic ring 22, inner upper radial magnetic ring 13, inner middle axial magnetic ring 17, inner lower radial magnetic ring 18, and upper axial magnetic ring 11 together form a closed air gap, creating a constant permanent magnet magnetic field within it. The outer yoke 25, upper yoke 10, inner yoke 12, and lower yoke 20 enclose the permanent magnet, effectively reducing magnetic leakage and enhancing the magnetic flux density of the air gap. At this time, the mover is in its initial position, and the upper coil 15 and lower coil 16 are not energized.

[0053] When current flows through the upper coil 15 and a reverse current flows through the lower coil 16, the electromagnetic fields generated by the upper coil 15 and the lower coil 16 are in opposite directions. The height of the upper coil 15 is greater than the height of the lower coil 16, and the distance between them is 1.5 to 2.5 times the height of the lower coil 16. This structure increases the magnetic flux density between the upper coil 15 and the lower coil 16. The energized upper coil 15 experiences an upward Ampere force due to the magnetic field generated by the upper radial magnetic ring. The lower coil 16, with a reverse current, also experiences an upward Ampere force due to the magnetic field generated by the lower radial magnetic ring and the magnetic fields generated by the bottom axial magnetic rings (lower inner axial magnetic ring 19 and lower outer axial magnetic ring 21). The lower inner axial magnetic ring 19 and the lower outer axial magnetic ring 21 form an auxiliary magnetic circuit. Specifically, the magnetic flux starts from the N pole of the lower inner axial magnetic ring 19, passes through the lower magnetic yoke 20, the S pole of the lower outer axial magnetic ring 21, the N pole of the lower outer axial magnetic ring 21, the outer lower radial magnetic ring 22, the air gap, the inner lower radial magnetic ring 18, and finally returns to the S pole of the lower inner axial magnetic ring 19. This auxiliary magnetic circuit enhances the magnetic field strength at the bottom of the air gap between the lower radial magnetic rings, increases the initial thrust, and causes the mover to start moving upward.

[0054] After the upper and lower coils move upwards a certain distance, they both enter the air gap between the upper radial magnetic rings. At this point, the energizing direction of the upper and lower coils remains unchanged, but because the electromagnetic fields generated by the upper and lower coils are in opposite directions, a stronger magnetic pole is formed, causing some of the magnetic flux in the air gap to pass between the upper and lower coils. Simultaneously, the thinner lower coil 16 creates a local magnetic flux loop, thereby enhancing the magnetic field strength near the upper coil 15 and guiding more magnetic flux through the gap between the upper and lower coils. This increases the Ampere force generated by the upper coil 15 in the air gap, and this increased Ampere force is greater than that experienced by the lower coil 16, thus increasing the thrust density of the device and enabling the mover to move upwards continuously and stably to meet the requirements of spacecraft separation and other missions. Throughout the entire operation, by adjusting the magnitude and direction of the current flowing through the upper coil 15 and the lower coil 16, the speed and direction of the mover can be precisely controlled, achieving regulation of the spacecraft separation speed.

[0055] The embodiments of the present invention disclosed above are merely illustrative of the invention. These embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.

Claims

1. A non-uniform height dual-coil electromagnetic actuation device, characterized in that: It includes a stator and a mover. The stator includes an upper magnetic structure (2), an outer magnetic structure (3), a lower magnetic structure (4), and an inner magnetic structure. The outer magnetic structure (3) includes an outer lower radial magnetic ring (22), an outer central axial magnetic ring (23), an outer upper radial magnetic ring (24), and an outer yoke (25). The outer upper radial magnetic ring (24) is installed on the upper inner side of the outer yoke (25). The outer central axial magnetic ring (23) is installed on the middle inner side of the outer yoke (25) and located below the outer upper radial magnetic ring (24). The outer lower radial magnetic ring (22) is installed on the lower inner side of the outer yoke (25) and located below the outer central axial magnetic ring (23). The inner magnetic structure includes an inner yoke (12), an inner upper radial magnetic ring (13), an inner central axial magnetic ring (17), and an inner... The lower radial magnetic ring (18), the inner upper radial magnetic ring (13) is installed on the upper part of the inner magnetic yoke (12), the inner central axial magnetic ring (17) is installed in the middle of the inner magnetic yoke (12) and located below the inner upper radial magnetic ring (13), the inner lower radial magnetic ring (18) is installed on the lower part of the inner magnetic yoke (12) and located below the inner central axial magnetic ring (17), the outer upper radial magnetic ring (24) is at the same height as the inner upper radial magnetic ring (13), the outer upper radial magnetic ring (24) and the inner upper radial magnetic ring (13) form the upper radial magnetic ring, the outer lower radial magnetic ring (22) is at the same height as the inner lower radial magnetic ring (18), the outer lower radial magnetic ring (22) and the inner lower radial magnetic ring (18) form the lower radial magnetic ring, the outer central axial magnetic ring (2 3) The outer central axial magnetic ring (23) and the inner central axial magnetic ring (17) are of the same height as the inner central axial magnetic ring (17). The outer central axial magnetic ring (23) and the inner central axial magnetic ring (17) form a middle layer axial magnetic ring. The height of the upper radial magnetic ring is greater than that of the lower radial magnetic ring. The upper and lower ends of the inner magnetic yoke (12) are respectively installed at the center of the upper magnetic structure (2) and the lower magnetic structure (4). The upper and lower ends of the outer magnetic yoke (25) are respectively installed at the edge of the upper magnetic structure (2) and the lower magnetic structure (4). There is an air gap between the radial inner side of the outer magnetic structure (3) and the radial outer side of the inner magnetic structure. The mover includes a mover coil frame (14), an upper coil (15) and a lower coil (16). The mover coil frame (14) is set in the air gap. The upper coil of the mover coil frame (14) is located on the outer side of the upper coil. Both the upper and lower parts are provided with annular grooves. An upper coil (15) and a lower coil (16) are respectively arranged in the annular grooves of the upper and lower parts. The height of the upper coil (15) is greater than the height of the lower coil (16). The current flowing through the upper coil (15) is opposite in direction to the current flowing through the lower coil (16). The upper magnetic structure (2) includes an upper magnetic yoke (10) and an upper axial magnetic ring (11). The upper axial magnetic ring (11) is installed on the lower side of the upper magnetic yoke (10). The upper end of the inner magnetic yoke (12) is installed at the center of the upper magnetic yoke (10). The upper end of the outer magnetic yoke (25) is installed at the edge of the upper magnetic yoke (10). The lower magnetic structure (4) includes a lower inner axial magnetic ring (19), a lower magnetic yoke (20), and a lower outer axial magnetic ring (21).The lower inner axial magnetic ring (19) is installed radially inner to the upper part of the lower magnetic yoke (20), and the lower outer axial magnetic ring (21) is installed radially outer to the upper part of the lower magnetic yoke (20). The lower end of the inner magnetic yoke (12) is installed at the center of the lower magnetic yoke (20), and the lower end of the outer magnetic yoke (25) is installed at the edge of the lower magnetic yoke (20). The height of the lower radial magnetic ring is the height of the lower coil (16) plus the distance between the upper coil (15) and the lower coil (16) plus the reserved installation height of the coil (16) minus the height of the middle axial magnetic ring. The height of the upper radial magnetic ring is 8-12 times the height of the lower radial magnetic ring.

2. The non-uniform height double-coil electromagnetic actuation device according to claim 1, characterized in that: It also includes a top plate (1), a linear motion base plate (7), a lower support rod (8) and an upper support rod (9). The lower support rod (8) and the upper support rod (9) are multiple rods, and they are evenly distributed along the circumference of the moving coil frame (14). One end of the lower support rod (8) is connected to the lower part of the moving coil frame (14), and the other end passes through the lower magnetic structure (4) and is connected to the linear motion base plate (7). One end of the upper support rod (9) is connected to the upper part of the moving coil frame (14), and the other end passes through the upper magnetic structure (2) and is connected to the top plate (1).

3. The non-uniform height double-coil electromagnetic actuation device according to claim 2, characterized in that: The lower magnetic structure (4) is connected to the stator frame at its lower part. The stator frame includes a base (5) and stator support rods (6). There are multiple stator support rods (6), which are evenly distributed along the circumference of the base (5). One end of each stator support rod (6) is connected to the base (5), and the other end is connected to the lower magnetic structure (4). The linear motion base plate (7) is slidably connected to the stator support rods (6).

4. The non-uniform height double-coil electromagnetic actuation device according to claim 3, characterized in that: The top plate (1), base (5), stator support rod (6), lower support rod (8) and upper support rod (9) are all made of hard aluminum alloy 2A12.

5. The non-uniform height double-coil electromagnetic actuation device according to claim 1, characterized in that: The materials of the lower inner axial magnetic ring (19), lower outer axial magnetic ring (21), outer upper radial magnetic ring (24), outer middle axial magnetic ring (23), outer lower radial magnetic ring (22), inner upper radial magnetic ring (13), inner middle axial magnetic ring (17), inner lower radial magnetic ring (18), and upper axial magnetic ring (11) are all neodymium iron boron N35 permanent magnet materials, and the magnetization directions are as follows: front S rear N, front N rear S, inner S outer N, front S rear N, inner N outer S, inner S outer N, front N rear S, inner N outer S, front S rear N.

6. The non-uniform height dual-coil electromagnetic actuation device according to claim 1, characterized in that: The outer yoke (25), inner yoke (12), upper yoke (10), and lower yoke (20) are all made of DT4C, and the mover coil frame (14) is made of polyimide.

7. The non-uniform height double-coil electromagnetic actuation device according to claim 1, characterized in that: The ratio of the height of the upper coil (15) to the height of the lower coil (16) is greater than or equal to 5 and less than or equal to 7, and the distance between the upper coil (15) and the lower coil (16) is 1.5 to 2.5 times the height of the lower coil (16).

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