Electromagnetic actuator for on-orbit servicing

Abstract

The application provides an electromagnetic actuator for space on-orbit service, and belongs to the field of aerospace. The electromagnetic actuator solves the problem of thrust density reduction when the existing electromagnetic actuator suppresses armature reaction. The electromagnetic actuator comprises 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 upper magnetic structure comprises 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 outer magnetic structure comprises an outer lower radial magnetic ring, an outer middle axial magnetic ring, an outer upper radial magnetic ring and an outer magnetic yoke. The outer upper radial magnetic ring is installed on the inner side upper part of the outer magnetic yoke. The outer middle axial magnetic ring is installed on the inner side middle part of the outer magnetic yoke and is located on the lower side of the outer upper radial magnetic ring. The outer lower radial magnetic ring is installed on the inner side lower part of the outer magnetic yoke and is located on the lower side of the outer middle axial magnetic ring. The electromagnetic actuator is mainly used for space on-orbit service.

Description

Technical Field

[0001] The present invention belongs to the field of aerospace, and in particular relates to an electromagnetic actuating device for space on-orbit service. Background Art

[0002] With the development of aerospace technology and the continuous exploration of space, various types of spacecraft have been launched into space to complete their respective scientific missions. Currently, a large number of spacecraft are operating in orbit, but some have reached the end of their service life, depleted their fuel, or experienced component damage, becoming space debris. However, through in-orbit repairs, component replacements, refueling, and rerouting, space servicing measures can extend the service life of spacecraft and reduce their operational costs.

[0003] For on-orbit spacecraft servicing missions, the servicing spacecraft must rendezvous and dock with the target spacecraft before refueling and performing maintenance services. After completing the servicing mission, the servicing spacecraft must re-separate from the target spacecraft and return it to its operational orbit. This process requires a reusable separation device with adjustable separation speeds for different spacecraft types, and electromagnetic actuators play a key role in this process.

[0004] Currently, existing electromagnetic actuating devices, such as the Chinese patent publication number CN113572334A, disclose a dual-magnetic-circuit electromagnetic actuator with compensating magnets. This actuator achieves permanent magnetic flux diversion by forming a front-to-rear dual permanent magnetic branch circuit on a single-layer magnetic pole structure, and utilizes end compensating magnets to increase the magnetomotive force and air gap magnetic field strength. However, these devices suffer from large end magnetic leakage, armature reaction caused by a single coil, and the lack of effective measures to suppress the armature reaction. Furthermore, the low magnetic field strength at the bottom of the air gap results in low initial thrust.

[0005] Chinese patent publication number CN113443176A discloses an electromagnetic actuator for a nanosatellite deployer. It utilizes multiple magnetic rings connected in series to form a single closed permanent magnet circuit to increase the magnetic field strength between the inner and outer air gaps. While this invention incorporates two air gaps, while increasing the actuator's speed range, the two air gaps also result in increased magnetic flux leakage at the ends. The lack of auxiliary permanent magnets at the bottom leads to weak magnetic field strength at the bottom of the two air gaps, resulting in low initial actuator thrust.

[0006] Chinese patent publication number CN113562203A discloses an electromagnetic actuator with a redundant air gap. This design utilizes a magnetic isolation ring to create a redundant air gap and an auxiliary permanent magnet circuit. While this approach increases the magnetic flux density at the end of the air gap, the coil generates a large electromagnetic field, which causes armature reaction, and this invention fails to reduce armature reaction. The permanent magnet arrangement at the bottom of the air gap creates a magnetic flux circuit within the lower magnetic ring, which weakens the air gap's magnetic field strength.

[0007] Chinese patent publication number CN113572335A discloses a single-pole electromagnetic actuator with dual windings. This actuator utilizes a guide magnetic ring to address the problem of magnetic field cancellation caused by opposing magnetic paths. By directing the magnetic flux of different branches, it reduces some magnetic flux leakage. However, the two-turn air gap still results in significant magnetic flux leakage. Furthermore, the radial arrangement of the two coils causes the electromagnetic field flux generated by the coils to return in the opposite direction to the magnetic flux return generated by the permanent magnets, thereby reducing the magnetic flux density in the air gap.

[0008] It can be seen that existing electromagnetic actuators have many problems, such as severe end magnetic leakage, low initial thrust, and difficulty in suppressing armature reaction. Current electromagnetic actuators use dual coils to pass reverse currents to generate opposite electromagnetic fields that cancel each other out, thereby suppressing armature reaction. However, existing actuators with a dual-coil design have large magnetic leakage and low thrust density, resulting in a low energy conversion rate. To meet the mission requirements of various types of spacecraft after completing on-orbit service and then separating, electromagnetic actuators must be able to suppress armature reaction, reduce the risk of demagnetization, and be able to operate stably in orbit for a long time, while still maintaining a certain thrust density. Summary of the Invention

[0009] In view of this, the present invention aims to propose an electromagnetic actuator for space on-orbit service to solve the problems of severe magnetic leakage, inability to suppress armature reaction and low thrust density of existing electromagnetic actuators.

[0010] To achieve the above-mentioned objectives, the present invention adopts the following technical solutions: an electromagnetic actuator for space on-orbit service, which includes a stator and a mover, the stator includes an upper magnetic structure, an outer magnetic structure, a lower magnetic structure and an inner magnetic structure, 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 outer magnetic structure includes an outer lower radial magnetic ring, an outer middle axial magnetic ring, an outer upper radial magnetic ring and an outer magnetic yoke, the outer upper radial magnetic ring is installed on the inner upper part of the outer magnetic yoke, the outer middle axial magnetic ring is installed on the inner middle part of the outer magnetic yoke and is located on the lower side of the outer upper radial magnetic ring, the outer lower radial magnetic ring is installed on the inner lower part of the outer magnetic yoke and is located on the lower side of the outer middle axial magnetic ring, the lower magnetic structure includes a lower inner axial magnetic ring, a lower magnetic yoke and a lower outer axial magnetic ring The lower inner axial magnetic ring is installed on the radial inner side of the upper part of the lower magnetic yoke, and the lower outer axial magnetic ring is installed on the radial outer side of the upper part of the lower magnetic yoke. The inner magnetic structure includes an inner magnetic yoke, an inner upper radial magnetic ring, an inner middle axial magnetic ring and an inner lower radial magnetic ring. The inner upper radial magnetic ring is installed on the upper part of the inner magnetic yoke, the inner middle axial magnetic ring is installed in the middle part of the inner magnetic yoke and is located on the lower side of the inner upper radial magnetic ring, the inner lower radial magnetic ring is installed on the lower part of the inner magnetic yoke and is located on the lower side of the inner middle axial magnetic ring, the upper and lower ends of the inner magnetic yoke are respectively installed at the center of the upper magnetic yoke and the lower magnetic yoke, the upper and lower ends of the outer magnetic yoke are respectively installed at the edges of the upper magnetic yoke and the lower magnetic yoke, there is an air gap between the radial inner side of the outer magnetic structure and the radial outer side of the inner magnetic structure, and the mover is arranged in the air gap.

[0011] Furthermore, the mover includes an upper coil, a mover coil frame and a lower coil. The mover coil frame is arranged in the air gap. Annular grooves are provided 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 of the upper and lower parts.

[0012] Furthermore, the mover also includes a top plate, a linear motion bottom plate, a lower support rod and an upper support rod. There are multiple lower support rods and upper support rods, and they are evenly distributed along the circumferential direction of the mover coil frame. One end of the lower support rod is connected to the lower part of the mover coil frame, and the other end is connected to the linear motion bottom plate after passing through the lower magnetic structure. One end of the upper support rod is connected to the upper part of the mover coil frame, and the other end is connected to the top plate after passing through the upper magnetic structure.

[0013] Furthermore, the lower part of the lower magnetic structure is connected to the stator frame, and the stator frame includes a base and a stator support rod. There are multiple stator support rods, and the multiple stator support rods are evenly distributed along the circumferential direction of the base. One end of the stator support rod is connected to the base, and the other end is connected to the lower magnetic yoke. The linear motion base plate is slidably connected to the stator support rod.

[0014] Furthermore, the materials of the top plate, the base, the stator support rod, the lower support rod and the upper support rod are all hard aluminum alloy 2A12.

[0015] Furthermore, the upper coil and the lower coil have the same height, the current passed through the upper coil is in the opposite direction to the current passed through the lower coil, the outer lower radial magnetic ring, the outer upper radial magnetic ring, the inner upper radial magnetic ring and the inner lower radial magnetic ring have the same height, the upper coil is located between the outer upper radial magnetic ring and the inner upper radial magnetic ring, and the lower coil is located between the outer lower radial magnetic ring and the inner lower radial magnetic ring.

[0016] Furthermore, the mover coil frame is made of polyimide material.

[0017] Furthermore, the magnetizing directions of the lower inner axial magnetic ring, the lower outer axial magnetic ring, the outer upper radial magnetic ring, the outer middle axial magnetic ring, the outer lower radial magnetic ring, the inner upper radial magnetic ring, the inner middle axial magnetic ring, the inner lower radial magnetic ring and the upper axial magnetic ring are: front N and back S, front S and back N, inside N and outside S, front N and back S, inside S and outside N, inside N and outside S, front S and back N, inside S and outside N, front S and back N.

[0018] Furthermore, the materials of the upper axial magnetic ring, the inner upper radial magnetic ring, the inner middle axial magnetic ring, the inner lower radial magnetic ring, the lower inner axial magnetic ring, the lower outer axial magnetic ring, the outer lower radial magnetic ring, the outer middle axial magnetic ring and the outer upper radial magnetic ring are all made of neodymium iron boron N35 permanent magnet material.

[0019] Furthermore, the materials of the upper magnetic yoke, the inner magnetic yoke, the lower magnetic yoke and the outer magnetic yoke are all DT4C.

[0020] Compared with existing technologies, the present invention offers the following advantages: It provides an electromagnetic actuator for on-orbit space servicing, suppressing the strong armature reaction problem of existing electromagnetic actuators while providing sufficient thrust density. This invention utilizes multiple layers of annular permanent magnets to form multiple closed permanent magnetic circuits. The enclosed yoke structure effectively reduces magnetic flux leakage, increases the strength of the air gap magnetic field, improves the uniformity of the air gap magnetic flux density, and reduces thrust fluctuations. Yoke saturation suppresses the armature reaction caused by the coil's electromagnetic field.

[0021] Before the coil is energized, the magnetic flux generated by the permanent magnet saturates the yoke. After the coil is energized, the electromagnetic flux generated by the coil is offset by the flux generated by the permanent magnet. However, the saturation of the yoke still creates a strong magnetic field in the air gap. A radially magnetized permanent magnet ring at the bottom of the air gap forms a localized magnetic flux loop, thereby enhancing the magnetic field strength at the bottom of the air gap and improving initial thrust.

[0022] The invention features a compact structure, small size, light weight, and a wide thrust adjustment range, meeting the current needs of on-orbit space services. It is used to separate multiple types of spacecraft after on-orbit maintenance, ensuring that the spacecraft separate at a predetermined speed.

[0023] This invention employs two coils of equal height, each fed with opposite currents. These coils generate opposing electromagnetic fields that cancel each other out, directing the Ampere force upward. By reducing the height of the yoke to saturate the yoke, the armature reaction generated by the coils is effectively suppressed, minimizing the risk of demagnetization of the permanent magnet ring. Furthermore, magnetic saturation reduces the amount of yoke material used, lowering the overall mass of the actuator and increasing thrust density.

[0024] The present invention uses multiple magnetic rings to form three main magnetic flux loops, and uses radially magnetized permanent magnet rings, external magnetic structures and internal magnetic structures at the ends to form local small magnetic flux loops to reduce leakage magnetic flux and increase the air gap magnetic density at the ends, thereby increasing the initial thrust. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0026] Figure 1 This is a schematic diagram of the three-dimensional structure of an electromagnetic actuating device for on-orbit space service according to the present invention;

[0027] Figure 2 This is a schematic diagram of the cross-sectional structure of the magnetic circuit of an electromagnetic actuator for on-orbit space service according to the present invention;

[0028] Figure 3 This is a schematic diagram of the three-dimensional structure of the mover according to the present invention;

[0029] Figure 4 This is a three-dimensional schematic diagram of the external magnetic structure of the present invention;

[0030] Figure 5 This is a three-dimensional schematic diagram of the internal magnetic structure of the present invention;

[0031] Figure 6 This is a three-dimensional schematic diagram of the upper magnetic structure of the present invention;

[0032] Figure 7 This is a three-dimensional schematic diagram of the lower magnetic structure of the present invention;

[0033] Figure 8 This is a three-dimensional schematic diagram of the stator frame of the present invention;

[0034] Figure 9 Schematic diagram of the magnetic circuit of the stator according to the present invention.

[0035] In the picture:

[0036] 1-top plate, 2-upper magnetic structure, 3-outer magnetic structure, 4-lower magnetic structure, 5-base, 6-linear motion base plate, 7-stator support rod, 8-lower support rod, 9-upper support rod, 10-upper magnetic yoke, 11-upper axial magnetic ring, 12-inner magnetic yoke, 13-inner upper radial magnetic ring, 14-upper coil, 15-inner middle axial magnetic ring, 16-mator coil frame, 17-lower coil, 18-inner lower radial magnetic ring, 19-lower inner axial magnetic ring, 20-lower magnetic yoke, 21-lower outer axial magnetic ring, 22-outer lower radial magnetic ring, 23-outer middle axial magnetic ring, 24-outer upper radial magnetic ring, 25-outer magnetic yoke. DETAILED DESCRIPTION

[0037] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely explain the technical solutions in the embodiments of the present invention. It should be noted that the embodiments of the present invention and the features therein can be combined with each other in the absence of conflict, and the embodiments described are only part of the embodiments of the present invention, not all of the embodiments.

[0038] See also Figure 1-8 The present embodiment describes an electromagnetic actuator for space on-orbit service, which includes a stator and a mover, wherein the stator includes an upper magnetic structure 2, an outer magnetic structure 3, a lower magnetic structure 4 and an inner magnetic structure, wherein the upper magnetic structure 2 includes an upper magnetic yoke 10 and an upper axial magnetic ring 11, wherein the upper axial magnetic ring 11 is mounted on the lower side of the upper magnetic yoke 10, the outer magnetic structure 3 includes an outer lower radial magnetic ring 22, an outer middle axial magnetic ring 23, an outer upper radial magnetic ring 24 and an outer magnetic yoke 25, wherein the outer upper radial magnetic ring 24 is mounted on the inner upper part of the outer magnetic yoke 25, the outer middle axial magnetic ring 23 is mounted on the inner middle part of the outer magnetic yoke 25 and is located below the outer upper radial magnetic ring 24, the outer lower radial magnetic ring 22 is mounted on the inner lower part of the outer magnetic yoke 25 and is located below the outer middle axial magnetic ring 23, 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, wherein the lower inner axial magnetic ring 19 The lower outer axial magnetic ring 21 is installed on the radial inner side of the upper part of the lower magnetic yoke 20, and the inner magnetic structure includes an inner magnetic yoke 12, an inner upper radial magnetic ring 13, an inner middle axial magnetic ring 15 and an inner 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 middle axial magnetic ring 15 is installed in the middle part of the inner magnetic yoke 12 and is located on the lower side of 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 is located on the lower side of the inner middle axial magnetic ring 15, the upper and lower ends of the inner magnetic yoke 12 are respectively installed at the center of the upper magnetic yoke 10 and the lower magnetic yoke 20 by bolts, the upper and lower ends of the outer magnetic yoke 25 are respectively installed at the edges of the upper magnetic yoke 10 and the lower magnetic yoke 20 by bolts, 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, and the mover is arranged in the air gap.

[0039] In this embodiment, the mover includes a top plate 1, a linear motion base plate 6, a lower support rod 8, an upper support rod 9, an upper coil 14, a mover coil frame 16, and a lower coil 17. The mover coil frame 16 is arranged in the air gap. The upper and lower parts of the outer side of the mover coil frame 16 are provided with annular grooves, and the upper coil 14 and the lower coil 17 are respectively arranged in the upper and lower annular grooves. There are four lower support rods 8 and four upper support rods 9, and the four lower support rods 8 and upper support rods 9 are evenly distributed along the circumference of the mover coil frame 16. One end of the lower support rod 8 is connected to the lower part of the mover coil frame 16, and the other end passes through the lower magnetic structure 4 and is connected to the linear motion base plate 6 by bolts. One end of the upper support rod 9 is connected to the upper part of the mover coil frame 16, and the other end passes through the upper magnetic structure 2 and is connected to the top plate 1 by bolts.

[0040] In this embodiment, the lower portion of the lower magnetic structure 4 is connected to the stator frame. The stator frame includes a base 5 and stator support rods 7. The stator support rods 7 are multiple and evenly distributed along the circumference of the base 5. One end of the stator support rod 7 is connected to the base 5 and the other end is connected to the lower magnetic yoke 20. The linear motion base plate 6 is slidably connected to the stator support rods 7. The mover cooperates with the linear motion base plate 6 and the stator support rods 7 to achieve linear motion of the mover. The upper coil 14 and the lower coil 17 are of the same height. The current flowing through the upper coil 14 is in the opposite direction to the current flowing through the lower coil 17. The outer lower radial magnetic ring 22, the outer upper radial magnetic ring 24, the inner upper radial magnetic ring 13, and the inner lower radial magnetic ring 18 are of the same height. The upper coil 14 is located between the outer upper radial magnetic ring 24 and the inner upper radial magnetic ring 13, and the lower coil 17 is located between the outer lower radial magnetic ring 22 and the inner lower radial magnetic ring 18.

[0041] In this embodiment, the top plate 1, base 5, stator support rod 7, lower support rod 8, and upper support rod 91 are all made of duralumin 2A12. The mover coil frame 16 is made of polyimide. The top plate 1 is connected to the upper support rod 9 with bolts, and the upper support rod 9 is connected to the mover coil frame 16 with threads. The linear motion base plate 6 is connected to the lower support rod 8 with bolts, and the lower support rod 8 is connected to the mover coil frame 16 with threads. The base 5 is connected to the stator support rod 7 with bolts, and the stator support rod 7 is connected to the lower magnetic yoke 20 with threads.

[0042] The magnetizing directions of 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 15, the inner lower radial magnetic ring 18 and the upper axial magnetic ring 11 described in this embodiment are: front N and back S, front S and back N, inside N and outside S, front N and back S, inside S and outside N, inside N and outside S, front S and back N, inside S and outside N, front S and back N.

[0043] The upper axial magnetic ring 11, the inner upper radial magnetic ring 13, the inner middle axial magnetic ring 15, the inner lower radial magnetic ring 18, the lower inner axial magnetic ring 19, the lower outer axial magnetic ring 21, the outer lower radial magnetic ring 22, the outer middle axial magnetic ring 23, and the outer upper radial magnetic ring 24 are all made of NdFeB N35 permanent magnet material. The upper magnetic yoke 10, the inner magnetic yoke 12, the lower magnetic yoke 20, and the outer magnetic yoke 25 are all made of DT4C.

[0044] This embodiment forms multiple closed permanent magnet circuits using multiple layers of annular permanent magnets. Its closed yoke structure effectively reduces magnetic flux leakage, increases the strength of the air gap magnetic field, improves the uniformity of the air gap magnetic flux density, and reduces thrust fluctuations. Yoke saturation suppresses armature reaction caused by the coil's electromagnetic field and reduces the risk of permanent magnet demagnetization under high-current conditions. This device features a compact structure, small size, light weight, and a wide thrust adjustment range, meeting the current practical needs of on-orbit space service and ensuring long-term stable performance. It is used to separate various types of spacecraft after on-orbit maintenance, ensuring separation at a predetermined speed.

[0045] The device described in this embodiment can form three main permanent magnetic closed loops, as follows:

[0046] Permanent magnetic closed loop 1: The magnetic flux starts from the N pole of the inner upper radial magnetic ring 13, passes through the inner magnetic yoke 12, the outer magnetic yoke 25, the S pole of the outer upper radial magnetic ring 24, the N pole of the outer upper radial magnetic ring 24, the air gap, and finally returns to the S pole of the inner upper radial magnetic ring 13.

[0047] Permanent magnetic closed loop 2: The magnetic flux starts from the N pole of the inner upper radial magnetic ring 13, passes through the inner magnetic yoke 12, the S pole of the inner lower radial magnetic ring 18, the N pole of the inner lower radial magnetic ring 18, the air gap, the S pole of the outer lower radial magnetic ring 22, the N pole of the outer lower radial magnetic ring 22, the outer magnetic yoke 25, the S pole of the outer upper radial magnetic ring 24, the S pole of the outer upper radial magnetic ring 24, the N pole of the outer upper radial magnetic ring 13, the air gap, and finally returns to the S pole of the inner upper radial magnetic ring 13.

[0048] Permanent magnet closed loop three: The magnetic flux originates from the north pole of the inner lower radial magnetic ring 18, passes through the air gap, the south pole of the outer lower radial magnetic ring 22, the north pole of the outer lower radial magnetic ring 22, the outer magnetic yoke 25, the lower magnetic yoke 20, the inner magnetic yoke 12, and finally returns to the south pole of the inner lower radial magnetic ring 18. 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 within the air gap.

[0049] 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. The auxiliary magnetic circuit is specifically as follows: 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.

[0050] During operation, 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 15, the inner lower radial magnetic ring 18, and the upper axial magnetic ring 11 form a closed air gap, generating a constant permanent magnetic field within 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 magnets, reducing magnetic flux leakage and enhancing the magnetic field density in the air gap. Current flows through the upper and lower coils 14 and 17, which are of equal height and move within the air gaps corresponding to the upper and lower radial magnetic rings, respectively. Because the upper coil 14 and the lower coil 17 are of equal height and the currents flow in opposite directions, the electromagnetic fields they generate are in opposite directions and cancel each other out. The yoke's magnetic flux saturation design effectively suppresses armature reaction. Simultaneously, current flows through both coils, generating an Ampere force in the same direction, both acting upward, thereby increasing the device's output thrust. The mover achieves linear motion through the coordination of the linear motion base plate 6 and the stator support rods 7. The top plate 1 and linear motion base plate 6 connect and transmit force during the mover's motion, while the upper and lower support rods 9 and 8 ensure the accuracy of the mover's motion direction. This entire device, generating linear motion in this manner, can be used for on-orbit spacecraft servicing, such as separating multiple types of spacecraft after on-orbit maintenance, ensuring that the spacecraft separate at a predetermined speed.

[0051] The embodiments of the present invention disclosed above are intended only to illustrate the present invention. The embodiments do not describe all details in detail, nor do they limit the present invention to the specific embodiments described. Numerous modifications and variations are possible based on the contents of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention.

Claims

1. An electromagnetic actuator for on-orbit space service, characterized by: It comprises a stator and a mover, wherein the stator comprises an upper magnetic structure (2), an outer magnetic structure (3), a lower magnetic structure (4) and an inner magnetic structure, wherein the upper magnetic structure (2) comprises an upper magnetic yoke (10) and an upper axial magnetic ring (11), wherein the upper axial magnetic ring (11) is mounted on the lower side of the upper magnetic yoke (10), wherein the outer magnetic structure (3) comprises an outer lower radial magnetic ring (22), an outer middle axial magnetic ring (23), an outer upper radial magnetic ring (24) and an outer magnetic yoke (25), wherein the outer upper radial magnetic ring (24) is mounted on the inner upper part of the outer magnetic yoke (25), wherein the outer middle axial magnetic ring (23) is mounted on the inner middle part of the outer magnetic yoke (25) and is located on the lower side of the outer upper radial magnetic ring (24), and wherein the outer lower radial magnetic ring (22) is mounted on the inner lower part of the outer magnetic yoke (25). The lower magnetic structure (4) comprises a lower inner axial magnetic ring (19), a lower magnetic yoke (20) and a lower outer axial magnetic ring (21), wherein the lower inner axial magnetic ring (19) is mounted on the radial inner side of the upper portion of the lower magnetic yoke (20), and the lower outer axial magnetic ring (21) is mounted on the radial outer side of the upper portion of the lower magnetic yoke (20), and the inner magnetic structure comprises an inner magnetic yoke (12), an inner upper radial magnetic ring (13), an inner middle axial magnetic ring (15) and an inner lower radial magnetic ring (18), wherein the inner upper radial magnetic ring (13) is mounted on the upper portion of the inner magnetic yoke (12), the inner middle axial magnetic ring (15) is mounted on the middle portion of the inner magnetic yoke (12) and is located on the lower side of the inner upper radial magnetic ring (13), and the inner lower radial magnetic ring (18) is mounted on the inner magnetic yoke (12). The lower part of the magnetic yoke (12) is located on the lower side of the inner central axial magnetic ring (15), the upper and lower ends of the inner magnetic yoke (12) are respectively installed at the center of the upper magnetic yoke (10) and the lower magnetic yoke (20), the upper and lower ends of the outer magnetic yoke (25) are respectively installed at the edges of the upper magnetic yoke (10) and the lower magnetic yoke (20), 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 is arranged in the air gap, the mover includes an upper coil (14), a mover coil frame (16) and a lower coil (17), the mover coil frame (16) is arranged in the air gap, the upper and lower parts of the outer side of the mover coil frame (16) are both provided with annular grooves, and the upper coil (14) is respectively arranged in the annular grooves of the upper and lower parts. ) and a lower coil (17), the mover further comprises a top plate (1), a linear motion bottom plate (6), a lower support rod (8) and an upper support rod (9), the lower support rod (8) and the upper support rod (9) are both multiple and are uniformly distributed along the circumferential direction of the mover coil frame (16), one end of the lower support rod (8) is connected to the lower part of the mover coil frame (16), and the other end passes through the lower magnetic structure (4) and is connected to the linear motion bottom plate (6), one end of the upper support rod (9) is connected to the upper part of the mover coil frame (16), and the other end passes through the upper magnetic structure (2) and is connected to the top plate (1), the upper coil (14) and the lower coil (17) have the same height, the current passed through the upper coil (14) is in the opposite direction to the current passed through the lower coil (17),The outer lower radial magnetic ring (22), the outer upper radial magnetic ring (24), the inner upper radial magnetic ring (13) and the inner lower radial magnetic ring (18) have the same height, the upper coil (14) is located between the outer upper radial magnetic ring (24) and the inner upper radial magnetic ring (13), the lower coil (17) is located between the outer lower radial magnetic ring (22) and the inner lower radial magnetic ring (18), and the magnetization directions of 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 (15), the inner lower radial magnetic ring (18) and the upper axial magnetic ring (11) are: front N back S, front S back N, inner N outside S, front N back S, inner S outside N, inner N outside S, front S back N, inner S outside N, front S back N, inner S outside N, front S back N.

2. The electromagnetic actuator for on-orbit space service according to claim 1, characterized in that: The lower portion of the lower magnetic structure (4) is connected to a stator frame, and the stator frame comprises a base (5) and a stator support rod (7). There are a plurality of stator support rods (7), and the plurality of stator support rods (7) are evenly distributed along the circumferential direction of the base (5). One end of the stator support rod (7) is connected to the base (5), and the other end is connected to the lower magnetic yoke (20). The linear motion base plate (6) is slidably connected to the stator support rod (7).

3. The electromagnetic actuator for space on-orbit servicing according to claim 2, characterized in that: The materials of the top plate (1), the base (5), the stator support rod (7), the lower support rod (8) and the upper support rod (9) are all hard aluminum alloy 2A12.

4. The electromagnetic actuator for on-orbit space service according to claim 3, characterized in that: The mover coil frame (16) is made of polyimide material.

5. The electromagnetic actuator for on-orbit space service according to claim 1, characterized in that: The materials of the upper axial magnetic ring (11), the inner upper radial magnetic ring (13), the inner middle axial magnetic ring (15), the inner lower radial magnetic ring (18), the lower inner axial magnetic ring (19), the lower outer axial magnetic ring (21), the outer lower radial magnetic ring (22), the outer middle axial magnetic ring (23) and the outer upper radial magnetic ring (24) are all nedium iron boron N35 permanent magnet materials.

6. The electromagnetic actuator for space on-orbit servicing according to claim 1, characterized in that: The materials of the upper magnetic yoke (10), the inner magnetic yoke (12), the lower magnetic yoke (20) and the outer magnetic yoke (25) are all DT4C.

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