Electrospray thruster

Abstract

The application discloses an electric spray thruster, relates to the technical field of electric thrusters, and can quickly position an emitter and an extraction grid, saves the mounting time of the thruster, and improves the consistency of the positions of the emitter and the extraction grid. The electric spray thruster comprises a shell, an emitter, a high-voltage electrode and an extraction grid, the shell has a containing cavity for containing propellant, and the inner wall of the shell is provided with a first limiting surface. The emitter is arranged in the containing cavity, and one end of the emitter is located below the liquid level of the propellant. The high-voltage electrode is fixedly sleeved outside the emitter, and the high-voltage electrode is arranged on the inner wall of the shell. The outer wall of the high-voltage electrode is provided with a second limiting surface which is limitedly matched with the first limiting surface and is used for limiting the relative position of the high-voltage electrode and the shell. The extraction grid is arranged at the outlet end of the shell, and one side of the extraction grid close to the containing cavity is provided with a protruding portion which extends into the containing cavity, the protruding portion is provided with a third limiting surface which is limitedly matched with the first limiting surface and is used for limiting the relative position of the extraction grid and the shell.

Description

Technical Field

[0001] This invention relates to the field of electric thruster technology, and more particularly to an electro-spray thruster. Background Technology

[0002] An electrospray thruster is an electrostatic thruster that uses a conductive liquid as the propellant. It utilizes an electrostatic field to extract and accelerate charged droplets or ions from the propellant. A strong electrostatic field is applied between the extraction grid and the emitter. Under the combined action of electrostatic force, propellant pressure, and surface tension, the liquid propellant at the emitter bends at the emitter tip, forming a Taylor cone. Subsequently, the propellant at the tip of the Taylor cone forms charged droplets or ions under the influence of electrostatic force, and is accelerated and ejected from the extraction grid orifice under the same electrostatic field, thus generating thrust.

[0003] A blade array ribs are provided at the top of the emitter. In actual installation, the blade array ribs are required to correspond with the lead-out grid holes. The assembly accuracy between the emitter and the lead-out grid will affect the extraction efficiency of charged droplets or charged ions, and thus affect the working performance and discharge stability of the thruster.

[0004] In the prior art, after the emitter is installed on the housing of the thruster, it is often necessary to place the fixed emitter under a high-powered optical microscope, then place the lead-out grid at the top of the housing, and adjust the position of the lead-out grid under the optical microscope so that all the blade array ridges of the emitter are located in the middle of the lead-out grid hole, and then install the lead-out grid on the housing.

[0005] Thus, in the existing technology, the assembly process of the lead-out gate and the emitter needs to be completed under a high-powered optical microscope. The alignment process of the emitter blade array ribs with the lead-out gate hole needs to be adjusted repeatedly, which takes a long time. Moreover, the error in each manual assembly process cannot be kept consistent, making it difficult to guarantee the consistency of the assembly position between the lead-out gate and the emitter. Summary of the Invention

[0006] The purpose of this invention is to provide an electrospray thruster in which the emitter and lead-out grid can be quickly positioned, saving the installation time of the thruster and improving the consistency of the position of the emitter and lead-out grid.

[0007] To achieve the above objectives, the present invention provides an electrospray thruster, comprising a housing, an emitter, a high-voltage electrode, and an extraction grid. The housing has a receiving cavity for containing propellant, and the inner wall of the housing has a first limiting surface. The emitter is disposed within the receiving cavity, with one end of the emitter located below the liquid surface of the propellant. The high-voltage electrode is fixedly sleeved outside the emitter and disposed on the inner wall of the housing. The outer wall of the high-voltage electrode is provided with a second limiting surface that limits the relative position of the high-voltage electrode and the housing. The extraction grid is located at the outlet end of the housing, and the side of the extraction grid near the receiving cavity has a protrusion extending into the receiving cavity. The protrusion has a third limiting surface that limits the relative position of the extraction grid and the housing.

[0008] When adopting the above technical solution, the electrospray thruster provided by the present invention includes a housing, an emitter, a high-voltage electrode, and an extraction grid. The housing has a receiving cavity for containing propellant, and the inner wall of the housing has a first limiting surface. The emitter is disposed in the receiving cavity, with one end of the emitter located below the liquid surface of the propellant. The high-voltage electrode is disposed on the inner wall of the housing, and the outer wall of the high-voltage electrode is provided with a second limiting surface that limits the relative position of the high-voltage electrode and the housing. Since the high-voltage electrode is fixedly sleeved outside the emitter, and the relative position of the high-voltage electrode and the housing is fixed, the relative position of the emitter and the housing can be fixed. In addition, the extraction grid has a protrusion extending into the receiving cavity on the side near the receiving cavity. The protrusion has a third limiting surface that limits the relative position of the extraction grid and the housing. Thus, it can be seen that the relative positions of the extraction grid, the housing, and the emitter are fixed through the limiting cooperation of the first limiting surface with the second and third limiting surfaces. During actual installation, the second and third limiting surfaces are matched with the first limiting surface to fix the positions of the lead-out grid, housing, and emitter, which can quickly position the emitter and lead-out grid, save the installation time of the thruster, and improve the consistency of the positions of the emitter and lead-out grid. Attached Figure Description

[0009] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0010] Figure 1 This is a front view schematic diagram of an electro-spray thruster in the prior art;

[0011] Figure 2 This is a top view of an existing electro-spray thruster.

[0012] Figure 3 This is a front view schematic diagram of an electro-spray thruster provided in an embodiment of the present invention;

[0013] Figure 4 This is a top view schematic diagram of the electro-spray thruster provided in an embodiment of the present invention;

[0014] Figure 5 This is a schematic diagram of the structure of the electro-spray thruster provided in an embodiment of the present invention.

[0015] Figure label:

[0016] 01—Casing, 02—Emitter, 03—High-voltage electrode, 04—Lead-out grid

[0017] 1—Shell, 11—First limiting surface, 12—Step, 2—Emitter, 3—High-voltage electrode

[0018] 31—Connecting part, 4—Lead-out gate, 41—Protrusion, 5—First threaded connector,

[0019] 6—Second threaded connector. Detailed Implementation

[0020] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

[0021] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0022] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. "Several" means one or more, unless otherwise explicitly specified.

[0023] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0025] Ionic liquid electrospray thrusters, as a novel type of micro-electric thruster, have already been applied in engineering applications on CubeSats and have been listed by NASA as one of the key micro-electric propulsion technologies for development. An electrospray thruster is an electrostatic thruster that uses a conductive liquid as the propellant. It utilizes an electrostatic field to extract and accelerate charged droplets or charged ions from the propellant. A strong electrostatic field is applied between the extraction grid and the emitter. Under the combined action of electrostatic force, propellant pressure, and surface tension, the liquid propellant at the emitter bends at the micrometer-sized emitter tip, forming a Taylor cone. Subsequently, the propellant at the tip of the Taylor cone forms charged droplets, charged ions, or a mixture of charged droplets and charged ions under the action of electrostatic force, and is accelerated and ejected from the extraction grid orifice under the same electrostatic field, thus generating thrust. Electrospray thrusters have many advantages, including high thrust accuracy, high specific impulse, small size, light weight, low power consumption, and ease of modularization. They are particularly suitable for the power requirements of micro and nanosatellite platforms and are currently a hot research area in the global electric propulsion field. Because charged ion liquid electrospray thrusters have relatively low thrust, their performance and service life in orbit are of great concern.

[0026] A blade array ribs are provided at the top of the emitter. In actual installation, the blade array ribs are required to correspond with the lead-out grid holes. The assembly accuracy between the emitter and the lead-out grid will affect the extraction efficiency of charged droplets or charged ions, and thus affect the working performance and discharge stability of the thruster.

[0027] Figure 1 and Figure 2 This is a schematic diagram of an electro-spray thruster currently in use. (Example) Figure 1 and Figure 2As shown, the structural parameters of the emitter 02 and the extraction grid of the ion liquid electrospray thruster are mainly on the order of millimeters and micrometers. The assembly precision between them affects the particle extraction efficiency, thus affecting the thruster's working performance and discharge stability. In the prior art, during actual installation, four positioning bolts are first used to fix the position of the high-voltage electrode 03 by engaging with the four positioning bolt mounting holes on the stepped end face inside the housing 01. The high-voltage electrode 03 is fixedly sleeved outside the emitter 02, thereby fixing the position of the emitter 02 relative to the housing 01 and aligning the axis of the emitter 02 with the axis of the housing 01. After the emitter 02 is installed on the housing 01 of the thruster, the emitter 02, which is fixed in position, is often placed under a high-power optical microscope. Then, the lead-out grid 04 is placed at the top of the housing 01, and the position of the lead-out grid 04 is adjusted under the optical microscope so that all the blade array ridges of the emitter 02 are located in the middle of the hole of the lead-out grid 04. Then, four positioning bolts are used to fix the position of the lead-out grid 04 by cooperating with the four positioning bolt mounting holes at the top of the housing 01, and the lead-out grid 04 is installed on the housing 01.

[0028] Although the existing assembly structure of the lead-out grid 04 and emitter 02 can meet the ground test requirements of the current ion liquid electrospray thruster to a certain extent, it still has the following shortcomings:

[0029] (1) The existing thruster lead-out grid 04 and emitter assembly process does not have a positioning structure. It mainly relies on the positioning accuracy of the positioning bolts and bolt holes to ensure the overall assembly accuracy. This assembly method itself will have a large lateral assembly error. Moreover, if the machining dimensions of any positioning bolt hole deviate to a certain extent, it will lead to an increase in the lateral assembly error between lead-out grid 04 and emitter 02, and may even result in difficulty in assembly.

[0030] (2) In the existing assembly process of lead-out gate 04 and emitter 02, it is mainly done manually under a high magnification optical microscope. The alignment process of the emitter 02 blade array ribs and the lead-out gate 04 hole needs to be adjusted repeatedly, which takes a long time. Moreover, the error in each manual assembly process is almost impossible to keep consistent, which makes it difficult to guarantee the consistency of the assembly position between lead-out gate 04 and emitter 02.

[0031] Specifically, the lateral assembly error of the ion liquid electrospray thruster manifests as the knife-edge-shaped ribs of the emitter 02 not being positioned in the center of the aperture of the lead-out grid 04. This results in an uneven distribution of the electric field intensity in the emission system, significantly affecting the trajectory of charged ions and particles. Some charged ions and droplets may be unable to exit the emission system due to impact with the lead-out grid 04, reducing the erosion life of the lead-out grid 04 and decreasing the performance of the charged ion liquid electrospray thruster. Furthermore, the difficulty in ensuring the consistency of the assembly position between the thruster lead-out grid 04 and the emitter 02 makes it difficult to determine the final delivered product condition.

[0032] In order to solve the technical problems existing in the prior art, such as Figures 3 to 5 As shown, this embodiment of the invention provides an electrospray thruster, including a housing 1, an emitter 2, a high-voltage electrode 3, and an outlet grid 4. The housing 1 has a receiving cavity for containing propellant, and the inner wall of the housing 1 has a first limiting surface 11. The emitter 2 is disposed in the receiving cavity, with one end of the emitter 2 located below the liquid surface of the propellant. The high-voltage electrode 3 is fixedly sleeved on the outside of the emitter 2 and disposed on the inner wall of the housing 1. The outer wall of the high-voltage electrode 3 is provided with a second limiting surface that limits the relative position of the high-voltage electrode 3 and the housing 1. The outlet grid 4 is covered at the outlet end of the housing 1, and the side of the outlet grid 4 near the receiving cavity has a protrusion 41 extending into the receiving cavity. The protrusion 41 has a third limiting surface that limits the relative position of the outlet grid 4 and the housing 1.

[0033] With the above technical solution, the electrospray thruster provided in this embodiment of the invention includes a housing 1, an emitter 2, a high-voltage electrode 3, and an extraction grid 4. The housing 1 has a receiving cavity for containing propellant, and the inner wall of the housing 1 has a first limiting surface 11. The emitter 2 is disposed in the receiving cavity, with one end of the emitter 2 located below the liquid surface of the propellant. The high-voltage electrode 3 is disposed on the inner wall of the housing 1, and the outer wall of the high-voltage electrode 3 is provided with a second limiting surface that limits and cooperates with the first limiting surface 11, thereby limiting the relative position of the high-voltage electrode 3 and the housing 1. Since the high-voltage electrode 3 is fixedly sleeved outside the emitter 2, and the relative position of the high-voltage electrode 3 and the housing 1 is fixed, the relative position of the emitter 2 and the housing 1 can be fixed. In addition, the extraction grid 4 has a protrusion 41 extending into the receiving cavity on the side near the receiving cavity. The protrusion 41 has a third limiting surface that limits and cooperates with the first limiting surface 11, thereby limiting the relative position of the extraction grid 4 and the housing 1. Therefore, it can be seen that the relative positions of the lead-out grid 4, housing 1, and emitter 2 are fixed by the limiting cooperation between the first limiting surface 11 and the second and third limiting surfaces. During actual installation, by fitting the second and third limiting surfaces with the first limiting surface 11, the relative positions of the lead-out grid 4, housing 1, and emitter 2 can be fixed. This allows for rapid positioning of the emitter 2 and lead-out grid 4, enabling rapid assembly of the electro-spray thruster's emitter 2 and lead-out grid 4, saving thruster installation time, improving the consistency of the positions of the emitter 2 and lead-out grid 4, reducing lateral assembly errors during the assembly of the lead-out grid hole and the blade-shaped ribs of the emitter 2, and ensuring consistency of lateral assembly errors between the two in each assembly.

[0034] In practice, the housing 1 has a cavity for containing propellant, which serves to store the propellant, making the propulsion system more compact in size and weight. The axes of the housing 1, the cavity, the emitter 2, the high-voltage electrode 3, and the lead-out gate 4 are all collinear. During the design process, the dimensions of the first limiting surface 11 and its position relative to the axis of the housing 1 are carefully designed. Simultaneously, the positions of the blade array ribs of the emitter 2 relative to its axis, the second limiting surface of the high-voltage electrode 3 relative to its axis, and the third limiting surface and lead-out gate hole of the lead-out gate 4 relative to its axis are also carefully designed. This ensures that after the second and third limiting surfaces are fitted with the first limiting surface 11, the blade array ribs correspond to the lead-out gate hole, and the blade-shaped ribs of the emitter 2 are located in the middle of the lead-out gate hole, resulting in a uniform electric field distribution in the propulsion system. Achieving good matching between the thruster emitter 2 and the extraction gate 4 ensures that particles are stably extracted in the accelerating electric field, thereby improving the thruster's performance and service life.

[0035] It should be noted that, in practice, the dimensions of the first, second, and third limiting surfaces are equal in the direction perpendicular to the housing axis. The limiting fit between the second and first limiting surfaces means that when the high-voltage electrode 3 is mounted on the housing 1, the second limiting surface on the high-voltage electrode 3 is coplanar and aligned with the first limiting surface of the housing 1, resulting in a tight fit between the two surfaces. Similarly, the limiting fit between the third and first limiting surfaces means that when the lead-out gate 4 is mounted on the housing 1, the third limiting surface of the protrusion on the lead-out gate 4 is coplanar and aligned with the first limiting surface of the housing 1, resulting in a tight fit between the two surfaces. Ultimately, this ensures that the axes of the housing 1, the receiving cavity, the emitter 2, the high-voltage electrode 3, and the lead-out gate 4 are all collinear, and the blade array ribs correspond to the lead-out gate holes.

[0036] As one possible implementation, the first limiting surface 11 is a plane. Correspondingly, the second and third limiting surfaces are also planes to facilitate the machining of the first limiting surface 11 and to facilitate the limiting fit between the first limiting surface 11 and the second and third limiting surfaces.

[0037] In some embodiments, the axes of the housing 1, the receiving cavity, the emitter 2, the high-voltage electrode 3, and the lead-out gate 4 are all collinear. There are two first limiting surfaces 11, which are arranged parallel to each other and symmetrically with respect to the axis of the housing 1. Correspondingly, there are also two second limiting surfaces, which are arranged parallel to each other and symmetrically with respect to the axis of the high-voltage electrode 3. There are also two third limiting surfaces, which are arranged parallel to each other and symmetrically with respect to the axis of the lead-out gate 4. Specifically, the dimensional tolerance between the third limiting surface and the axis of the lead-out gate 4 is -0.02 mm to -0.01 mm, meaning the difference between the actual distance of the third limiting surface from the axis of the lead-out gate 4 and a preset distance is within the range of -0.02 mm to -0.01 mm. The dimensional tolerance of the first limiting surface 11 from the axis of the housing 1 is 0.01mm to 0.02mm, meaning the difference between the actual distance of the first limiting surface 11 from the axis of the housing 1 and the preset distance is within the range of 0.01mm to 0.02mm. The dimensional tolerance of the second limiting surface from the axis of the high-voltage electrode 3 is -0.01mm to 0mm, meaning the difference between the actual distance of the second limiting surface from the axis of the high-voltage electrode 3 and the preset distance is within the range of -0.01mm to 0mm, thereby ensuring the positioning accuracy of the designed and assembled thruster structure.

[0038] In one example, such as Figure 3As shown, the inner wall of the receiving cavity has a step 12, and the high-voltage electrode 3 has a connecting part 31 that mates with the step 12. This facilitates the installation of the high-voltage electrode 3 on the housing 1 and improves the stability of the high-voltage electrode 3 on the housing 1. The high-voltage electrode 3 can be fastened to the housing 1 by multiple first threaded connectors 5. The first threaded connectors 5 can be bolts. Threaded holes that mate with the first threaded connectors 5 are opened on the step 12. The top end of the first threaded connector 5 passes through the connecting part 31 of the high-voltage electrode 3 and is then installed in the threaded hole on the step 12, thereby fastening the high-voltage electrode 3 to the housing 1. The multiple first threaded connectors 5 are evenly arranged along the axial direction of the housing 1 to ensure the positioning accuracy of the high-voltage electrode 3 and the housing 1, and to make the force on the high-voltage electrode 3 and the housing 1 more even. In addition, the high-voltage electrode 3 is fastened to the housing 1 by the first threaded connectors 5, making the connection between the high-voltage electrode 3 and the housing 1 detachable. This facilitates the disassembly of the high-voltage electrode 3 and the housing 1 for individual maintenance or replacement.

[0039] In one possible implementation, such as Figure 1 and Figure 2 As shown, the lead-out grid 4 is fastened to the housing 1 by multiple second threaded connectors 6. The second threaded connectors 6 can be bolts. Threaded holes that mate with the second threaded connectors 6 are formed on the top surface of the housing 1. The top end of the second threaded connector 6 passes through the lead-out grid 4 and is installed in the threaded hole on the top surface of the housing 1, thereby fixing the lead-out grid 4 to the housing 1. The multiple second threaded connectors 6 are evenly arranged along the axial direction of the housing 1 to ensure accurate positioning of the lead-out grid 4 and the housing 1, and to ensure relatively uniform stress on the lead-out grid 4 and the housing 1. Furthermore, the fastening of the lead-out grid 4 to the housing 1 by the second threaded connectors 6 makes the connection between the lead-out grid 4 and the housing 1 detachable, facilitating disassembly of the lead-out grid 4 and the housing 1 for individual maintenance or replacement.

[0040] In some embodiments, the thickness of the protrusion 41 is 2mm-5mm to improve the strength of the protrusion 41 and prevent deformation of the protrusion 41 from affecting the assembly accuracy of the lead-out gate 4 and the housing 1, and further affecting the assembly accuracy of the lead-out gate 4 and the emitter 2. Exemplarily, the thickness of the protrusion 41 is 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, etc., and is not specifically limited here. The protrusion 41 can be a rectangular plate structure, and the thickness of the protrusion 41 is the distance from the third limiting surface to the side of the protrusion 41 away from the first limiting surface 11. The protrusion 41 can be integrally formed with the lead-out gate 4 or it can be a separate part. A chamfer is provided on the side of the protrusion 41 away from the lead-out gate 4 located on the first limiting surface 11 to prevent the transition fit between the protrusion 41 and the housing 1 during assembly from affecting the accuracy of the limiting fit between the first limiting surface 11 and the third limiting surface.

[0041] As an alternative, along the axial direction of the housing 1, the size of the overlapping area between the third limiting surface and the first limiting surface 11 is 1 / 2 to 2 / 3 of the size of the first limiting surface 11. This ensures sufficient contact area between the lead-out gate 4 and the housing 1, and ensures the assembly accuracy of the lead-out gate 4 and the emitter 2, as well as sufficient strength of the thruster.

[0042] In summary, the precise assembly of the emitter 2 and lead-out grid 4 of the electro-spray thruster provided in this embodiment of the invention can achieve precise positioning of the lead-out grid hole and the blade array ribs of the emitter 2 through the clearance fit between the third limiting surface on the lead-out grid 4, the second limiting surface of the high-voltage electrode 3 and the first limiting surface 11 of the housing 1, and the threaded connector. This reduces the lateral assembly error between the lead-out grid 4 and the emitter 2, has strong versatility, and is simple to operate. While ensuring accurate positioning, it can significantly shorten the assembly time. In actual installation, it is not necessary to repeatedly adjust the alignment position of the lead-out grid 4 and the emitter 2 under an optical microscope, reducing the number of manual operations. The thruster installation can be completed through the clearance fit between the third limiting surface, the second limiting surface of the high-voltage electrode 3 and the first limiting surface 11 of the housing 1, ensuring the consistency of assembly positioning accuracy and assembly error, thereby improving the working performance and service life of the thruster. Taking an ion liquid electrospray thruster with an outer envelope size of 5cm x 5cm x 5cm as an example, compared with a thruster without a positioning structure, the lateral assembly error of the lead-out grid 4 and emitter 2 of the thruster with a precision assembly structure designed in this invention can be reduced by 10% to 15%, and the working performance of the thruster can be improved by 5% to 10%.

[0043] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0044] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An electrospray thruster, characterized by, The application relates to a shell for a propellant, which comprises: a shell having a containing cavity for containing propellant; an inner wall of the shell has a first limiting surface; an emitter arranged in the containing cavity, one end of the emitter being below the liquid level of the propellant; a high-voltage electrode fixedly sleeved outside the emitter, the high-voltage electrode being arranged on the inner wall of the shell; an outer wall of the high-voltage electrode is provided with a second limiting surface in limiting cooperation with the first limiting surface, for limiting the relative position of the high-voltage electrode and the shell; an extraction grid arranged on the outlet end of the shell; one side of the extraction grid close to the containing cavity is provided with a protruding part extending into the containing cavity, the protruding part having a third limiting surface in limiting cooperation with the first limiting surface, for limiting the relative position of the extraction grid and the shell; the inner wall of the containing cavity has a step; the high-voltage electrode has a connecting part matched with the step; the high-voltage electrode is tightly arranged on the shell through a plurality of first threaded connecting pieces; the first threaded connecting pieces are installed in threaded holes on the step after penetrating through the connecting part of the high-voltage electrode; the first limiting surface is a plane; the number of the first limiting surfaces is two, the two first limiting surfaces are arranged in relative parallelism and symmetry with respect to the axis of the shell.

2. The electrospray thruster of claim 1, wherein, The plurality of first threaded connecting pieces are uniformly arranged along the axial direction of the shell.

3. The electrospray thruster of claim 1, wherein, The extraction grid is tightly arranged on the shell through a plurality of second threaded connecting pieces.

4. The electrospray thruster of claim 3, wherein, The plurality of second threaded connecting pieces are uniformly arranged along the axial direction of the shell.

5. The electrospray thruster of claim 1, wherein, The thickness of the protruding part is 2 mm-5 mm.

6. The electrospray thruster of claim 1, wherein, Along the axial direction of the shell, the size of the overlapping area of the third limiting surface and the first limiting surface is 1 / 2-2 / 3 of the size of the first limiting surface.

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