Grid mounting structure capable of releasing thermal strain

Abstract

The invention relates to the technical field of space propulsion, in particular to a grid mounting structure capable of releasing thermal strain, which comprises a screen grid, a screen grid mounting assembly and a total mounting ring, and is characterized in that the screen grid mounting assembly comprises a supporting ring and a fixing ring, one end of the fixing ring is fixedly connected with the supporting ring, and the other end of the fixing ring is fixedly connected with the total mounting ring; the other end of the fixing ring and the end face of the supporting ring form a clamping area, and the lower space in the middle of the fixing ring and the upper space in the middle of the supporting ring form a non-clamping area. The main installation ring is of an L-shaped rotating body structure. Through the design of incomplete fixed clamping and the guide rail, the screen grid is restrained in the axial direction and the circumferential direction and is not restrained in the radial direction, so that the screen grid can expand in the radial direction, the edge of the screen grid does not warp, hole alignment does not move in the circumferential direction to generate angular torque, meanwhile, radial release of thermal strain of the screen grid can be achieved, and the screen grid can expand in the radial direction. In other words, on the premise that the performance of the grid electrode is not affected, it is guaranteed that a certain margin exists between the grid spacing and the safety spacing during thermal strain.

Description

Technical Field

[0001] The present application relates to the field of space propulsion technology, and in particular to a gate mounting structure capable of releasing thermal strain. Background Art

[0002] As an advanced space propulsion technology, electric propulsion technology has been widely used in various application fields in space, including attitude control, north-south position keeping, orbit transfer, atmospheric damping compensation, main propulsion for deep space exploration, etc. Especially in deep space exploration missions, electric propulsion technology has strong advantages due to its high specific impulse and long life, which can greatly save the amount of propellant carried and increase the proportion of spacecraft payload.

[0003] As human beings continue to deepen their space exploration, the speed increment required for the exploration mission is getting larger and larger, which requires the support of high-power ion thrusters. The grid assembly of high-power ion thrusters has the characteristics of large aperture and large grid temperature gradient. These characteristics cause large thermal deformation of the grid when the high-power ion thruster is started. The axial thermal expansion causes the grid spacing (generally less than 1mm) to decrease. Under the high voltage between the grids (generally greater than 1000V), sparks, short circuits and other faults occur, resulting in problems such as failure to start normally or shutdown due to failure.

[0004] In order to ensure the consistency of thermal deformation direction, the grid assembly of the ion thruster generally adopts a spherical structure. Under the fixed edge constraint, axial deformation will cause the grid spacing to decrease. Since the screen grid has the highest geometric transparency and is in direct contact with the plasma in the discharge chamber, the thermal deformation is the greatest. When a high-power ion thruster is started, the axial expansion of the screen grid due to thermal strain will cause insufficient grid spacing, which may cause sparks, short circuits and other faults. Summary of the invention

[0005] The present application provides a grid installation structure capable of releasing thermal strain. By setting a non-completely fixed clamping and guide rail structure, the screen grid is only constrained in the axial and circumferential directions, but not in the radial direction, thereby achieving radial release of the thermal strain of the screen grid.

[0006] In order to achieve the above-mentioned purpose, the present application provides a grid installation structure that can release thermal strain, including a screen grid, a screen grid installation assembly and a total installation ring, wherein: the screen grid installation assembly includes a support ring and a fixed ring, one end of the fixed ring is fixedly connected to the support ring, the other end of the fixed ring forms a clamping area with the end face of the support ring, and the lower space in the middle of the fixed ring and the upper space in the middle of the support ring form a non-clamping area; a plurality of first mounting ears are evenly distributed along the circumference of the edge of the support ring, and a plurality of guide rails are evenly distributed along the circumference of the middle position of the support ring, and the plurality of guide rails are all arranged in the non-clamping area; a plurality of slide grooves are evenly distributed along the circumference of the edge of the screen grid, and the screen grid as a whole is fixed between the fixed ring and the support ring through the clamping area, and the outer edge of the screen grid extends into the non-clamping area, so that the plurality of slide grooves are correspondingly matched and connected with the plurality of guide rails; the total installation ring is an L-shaped rotating body structure, and a plurality of second mounting ears are evenly distributed along its circumference, and the plurality of first mounting ears are correspondingly matched and connected with the plurality of second mounting ears, so that the support ring is fixed on the total installation ring.

[0007] Furthermore, the height of the clamping area is greater than the thickness of the screen grid, the height of the clamping area is 0.02-0.05 mm greater than the thickness of the screen grid along the axial direction, and the width of the clamping area is 2-5 mm.

[0008] Furthermore, the height of the non-clamping area is 2-3 times the thickness of the screen grid.

[0009] Furthermore, the materials of the support ring and the fixing ring are both molybdenum alloy, and the end faces of the fixing ring and the support ring forming the clamping area are both provided with molybdenum disulfide coatings.

[0010] Furthermore, the minimum distance between the slide groove and the central axis is smaller than the minimum distance between the guide rail and the central axis.

[0011] Further, the outer diameter of the screen grid is smaller than the outer diameter of the non-clamping area.

[0012] Furthermore, a plurality of L-shaped grooves are provided on the inner side of the general mounting ring, and the plurality of L-shaped grooves are correspondingly connected to the plurality of second mounting ears to form a plurality of cantilever beam structures, and the directions of the L-shaped grooves of two adjacent cantilever beam structures are opposite.

[0013] Furthermore, the acceleration grid mounting interfaces and the ion thruster mounting interfaces are evenly distributed along the circumference of the overall mounting ring.

[0014] The present application provides a gate mounting structure capable of releasing thermal strain, which has the following beneficial effects:

[0015] The present application constrains the screen grid in the axial and circumferential directions through the design of non-completely fixed clamping and guide rails, but has no radial constraint, so that it can expand radially. This prevents the screen grid from warping at the edge, and the hole alignment does not move circumferentially to generate angular torque. At the same time, it can also achieve radial release of the thermal strain of the screen grid, that is, it ensures that the grid spacing has a certain margin from the safety spacing during thermal strain while ensuring that the grid performance is not affected. This solves the problems of sparking, short circuit, etc. caused by insufficient grid spacing due to axial expansion of the screen grid thermal strain when a high-power ion thruster is started; and in order to ensure the adequacy of the thermal strain release, a cantilever beam-shaped support structure is designed on the general mounting ring, and the circumferential fixation of the grid is ensured by designing adjacent cantilever beams in opposite directions. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings constituting a part of this application are used to provide a further understanding of this application, so that other features, purposes and advantages of this application become more obvious. The schematic embodiment drawings and their descriptions of this application are used to explain this application and do not constitute an improper limitation on this application. In the drawings:

[0017] Figure 1 is a schematic diagram of a gate mounting structure capable of releasing thermal strain according to an embodiment of the present application;

[0018] Figure 2 is a schematic diagram of a support ring of a gate mounting structure capable of releasing thermal strain according to an embodiment of the present application;

[0019] Figure 3 is a schematic diagram of a fixing ring of a gate mounting structure capable of releasing thermal strain according to an embodiment of the present application;

[0020] Figure 4 is a cross-sectional view of a connection area after a fixing ring and a supporting ring of a gate mounting structure capable of releasing thermal strain provided in an embodiment of the present application are combined;

[0021] Figure 5 is a schematic diagram of a screen grid of a grid installation structure capable of releasing thermal strain provided in an embodiment of the present application;

[0022] Figure 6 is a schematic diagram of a total mounting ring of a gate mounting structure capable of releasing thermal strain according to an embodiment of the present application;

[0023] In the figure: 1-screen grid, 11-slide groove, 2-support ring, 21-first mounting ear, 22-guide rail, 3-fixing ring, 4-total mounting ring, 41-second mounting ear, 42-L-shaped groove, 43-acceleration grid mounting interface, 44-ion thruster mounting interface, 5-clamping area, 6-non-clamping area. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0025] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0026] In the present application, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.

[0027] In addition, some of the above terms may be used to express other meanings in addition to indicating orientation or positional relationship. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this application can be understood according to specific circumstances.

[0028] In addition, the term "plurality" shall mean two or more.

[0029] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0030] like Figure 1-5As shown, the present application provides a grid installation structure capable of releasing thermal strain, including a screen grid 1, a screen grid installation assembly and a total installation ring 4, wherein: the screen grid installation assembly includes a support ring 2 and a fixed ring 3, one end of the fixed ring 3 is fixedly connected to the support ring 2, the other end of the fixed ring 3 and the end surface of the support ring 2 form a clamping area 5, and the lower space in the middle of the fixed ring 3 and the upper space in the middle of the support ring 2 form a non-clamping area 6; a plurality of first installation ears 21 are evenly distributed along the circumference of the edge of the support ring 2, and a plurality of guide ears 21 are evenly distributed along the circumference of the middle position of the support ring 2. Rail 22, multiple guide rails 22 are all arranged in the non-clamping area 6; multiple slide grooves 11 are evenly distributed along the circumference of the edge of the screen grid 1, the screen grid 1 is fixed between the fixing ring 3 and the support ring 2 as a whole through the clamping area 5, and the outer edge of the screen grid 1 extends into the non-clamping area 6, so that the multiple slide grooves 11 are correspondingly matched and connected with the multiple guide rails 22; the total mounting ring 4 is an L-shaped rotating body structure, and multiple second mounting ears 41 are evenly distributed along its circumference, and multiple first mounting ears 21 are correspondingly matched and connected with multiple second mounting ears 41, so that the support ring 2 is fixed on the total mounting ring 4.

[0031] Specifically, the gate mounting structure capable of releasing thermal strain provided in the embodiment of the present application is mainly used to fix the screen gate 1 of the thruster. The overall structure adopts a "sandwich"-like structure, clamping the screen gate L between the screen gate mounting components. When the screen gate 1 is heated and thermally strained during operation, it expands radially under the guidance of the guide rail 22 of the screen gate mounting component, thereby reducing the expansion in the axial direction. Among them, the screen grid installation assembly is mainly used to fix and clamp the screen grid 1, and is composed of a support ring 2 and a fixing ring 3. The support ring 2 is arranged at the bottom and is in a concave shape as a whole, but the end face of its outer edge is higher than the end face of the inner edge. The fixing ring 3 is arranged at the top and is in a side L shape as a whole. The end face of its outer edge is fixed to the end face of the outer edge of the support ring 2 by laser or electron beam welding, so that the fixing ring 3 is fixed on the support ring 2 to form an integrated structure; after the fixed combination, the end face of the inner edge of the fixing ring 3 is arranged correspondingly to the end face of the inner edge of the support ring 2 up and down, leaving a small gap in the middle, thereby forming a clamping area 5 for clamping the screen grid 1; and there is also a gap between the middle ring surface of the fixing ring 3 and the middle ring surface of the support ring 2, and the gap is relatively large, forming a non-clamping area 6, which reduces the resistance of the screen grid 1 during radial sliding and leaves space for the radial expansion of the screen grid 1 when heated. In the embodiment of the present application, eight guide rails 22 are evenly distributed along the circumference of the middle position of the support ring 2, and the eight guide rails 22 are all set in the non-clamping area 6. Similarly, eight slide grooves 11 are evenly distributed along the circumference of the edge of the screen grid 1, and the positions of the eight slide grooves 11 and the eight guide rails 22 are correspondingly set; when the thermal strain of the screen grid 1 is released, the screen grid 1 will expand radially through the cooperation of the slide grooves 11 and the guide rails 22 to ensure that its circumferential position remains unchanged, thereby ensuring the alignment of the small holes of the screen grid 1 and the small holes of the acceleration grid to prevent angular torque from being generated when the ion thruster is working. The total mounting ring 4 is mainly used for fixed support of the overall structure and for connecting with the ion thruster and other accessories. Twelve first mounting ears 21 are evenly distributed along the circumference of the edge of the support ring 2, and 12 second mounting ears 41 are evenly distributed along the circumference of the total mounting ring 4. The first mounting ears 21 and the second mounting ears 41 are connected in a one-to-one correspondence through bolts or pin structures, so that the support ring 2 is fixed on the total mounting ring 4, so that the screen grid 1 as a whole can be fixedly installed on the total mounting ring 4, realizing the overall assembly of the ion thruster grid assembly.

[0032] Furthermore, the height of the clamping area 5 is greater than the thickness of the screen grid 1 , the height of the clamping area 5 is 0.02-0.05 mm greater than the thickness of the screen grid 1 in the axial direction, and the width of the clamping area 5 is 2-5 mm.

[0033] Furthermore, the height of the non-clamping region 6 is 2-3 times the thickness of the screen grid 1 .

[0034] Furthermore, the materials of the support ring 2 and the fixing ring 3 are both molybdenum alloys, and the end surfaces of the fixing ring 3 and the support ring 2 forming the clamping area 5 are both provided with molybdenum disulfide coatings.

[0035] Specifically, the screen grid 1 is clamped and fixed between the support ring 2 and the fixing ring 3, the height of the clamping area 5 is slightly larger than the thickness of the screen grid 1, and there is a movable space of 0.02-0.05mm in the axial direction, thereby realizing the axial non-complete fixed constraint of the screen grid 1 to reduce the resistance of the screen grid 1 when the thermal strain is released, and at the same time ensuring that the edge of the screen grid 1 will not be obviously warped, wrinkled, etc. under the action of thermal deformation; the overall width of the clamping area 5 is 2-5mm, ensuring that only the edge of the screen grid 1 is clamped and fixed, and will not affect the grid hole; the height of the non-clamping area 6 is 2-3 times the thickness of the screen grid 1, ensuring that the area will not directly contact the screen grid 1; and the materials of the support ring 2 and the fixing ring 3 are both molybdenum alloys, and the upper and lower end surfaces of the clamping area 5 are provided with molybdenum disulfide coatings by surface modification or spraying, that is, the lower surface of the inner edge end surface of the fixing ring 3 and the upper surface of the inner edge end surface of the support ring 2 are provided with molybdenum disulfide coatings to reduce resistance.

[0036] Furthermore, the minimum distance between the slide groove 11 and the central axis is smaller than the minimum distance between the guide rail 22 and the central axis.

[0037] Furthermore, the outer diameter of the screen grid 1 is smaller than the outer diameter of the non-clamping area 6 .

[0038] Specifically, the minimum distance between the slide groove 11 and the central axis is more than 2 mm smaller than the minimum distance between the guide rail 22 and the central axis, and the outer diameter of the screen grid 1 is more than 2 mm smaller than the outer diameter (length) of the non-clamping area 6, ensuring that the screen grid 1 can move on the guide rail 22 of the non-clamping area 6 through the slide groove 11 when thermal strain occurs, and has sufficient radial expansion and sliding release space, and reduces the axial thermal deformation of the screen grid 1 through radial sliding release, thereby ensuring a safe spacing between grids during thermal strain.

[0039] Further, such as Figure 6 As shown, a plurality of L-shaped grooves 42 are provided on the inner side of the total mounting ring 4, and the plurality of L-shaped grooves 42 are correspondingly connected to the plurality of second mounting ears 41 to form a plurality of cantilever beam structures, and the directions of the L-shaped grooves 42 of two adjacent cantilever beam structures are opposite. In order to ensure sufficient release of thermal strain, 12 L-shaped grooves 42 are provided on the inner side of the total mounting ring 4, and each L-shaped groove 42 is fixedly connected to a second mounting ear 41, thereby forming a cantilever beam type fixed support structure, and the adjacent cantilever beams are designed in opposite directions, that is, 6 of the L-shaped grooves 42 are in the counterclockwise direction and the other 6 are in the clockwise direction, so as to ensure the circumferential fixation of the screen grid 1.

[0040] Furthermore, there are evenly distributed acceleration grid mounting interfaces 43 and ion thruster mounting interfaces 44 along the circumference of the overall mounting ring 4. The overall mounting ring 4 is also provided with an acceleration grid mounting interface 43 docked with the acceleration grid, and an ion thruster mounting interface 44 fixedly connected with the ion thruster.

[0041] Specifically, the thermally strain-releasing gate mounting structure provided in the embodiment of the present application ensures that the axial and circumferential positions of the screen gate 1 are fixed, and through the design of non-completely fixed clamping and guide rails 22, the screen gate 1 is radially unconstrained and can expand radially. That is, while ensuring the performance and mechanical resistance of the screen gate 1, it solves the problem of sparking, short circuit and other faults caused by insufficient gate spacing due to axial thermal strain expansion of the screen gate 1 when a high-power ion thruster is started.

[0042] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A gate mounting structure capable of releasing thermal strain, characterized in that: It includes a screen grid, a screen grid mounting assembly and a total mounting ring, wherein: The screen grid mounting assembly comprises a support ring and a fixing ring, one end of the fixing ring is fixedly connected to the support ring, the other end of the fixing ring forms a clamping area with the end surface of the support ring, and the lower space in the middle of the fixing ring and the upper space in the middle of the support ring form a non-clamping area; A plurality of first mounting ears are evenly distributed along the circumference of the edge of the support ring, a plurality of guide rails are evenly distributed along the circumference of the middle position of the support ring, and the plurality of guide rails are all arranged in the non-clamping area; A plurality of slide grooves are evenly distributed along the circumference of the edge of the screen grid, the screen grid as a whole is fixed between the fixing ring and the support ring through the clamping area, and the outer edge of the screen grid extends into the non-clamping area, so that the plurality of slide grooves are correspondingly matched and connected with the plurality of guide rails; The total mounting ring is an L-shaped rotating body structure, and a plurality of second mounting ears are evenly distributed along its circumference. The plurality of first mounting ears are correspondingly matched and connected with the plurality of second mounting ears, so that the support ring is fixed on the total mounting ring.

2. The gate mounting structure capable of releasing thermal strain according to claim 1, characterized in that: The height of the clamping area is greater than the thickness of the screen grid, the height of the clamping area is 0.02-0.05 mm greater than the thickness of the screen grid along the axial direction, and the width of the clamping area is 2-5 mm.

3. The gate mounting structure capable of releasing thermal strain according to claim 2, characterized in that: The height of the non-clamping area is 2-3 times the thickness of the screen grid.

4. The gate mounting structure capable of releasing thermal strain according to claim 3, characterized in that: The support ring and the fixing ring are both made of molybdenum alloy, and the end surfaces of the fixing ring and the support ring forming a clamping area are both provided with molybdenum disulfide coatings.

5. The gate mounting structure capable of releasing thermal strain according to claim 4, characterized in that: The minimum distance between the slide groove and the central axis is smaller than the minimum distance between the guide rail and the central axis.

6. The gate mounting structure capable of releasing thermal strain according to claim 5, characterized in that: The outer diameter of the screen grid is smaller than the outer diameter of the non-clamping area.

7. The gate mounting structure capable of releasing thermal strain according to claim 6, characterized in that: A plurality of L-shaped grooves are arranged on the inner side of the general mounting ring, and the plurality of L-shaped grooves are correspondingly connected with the plurality of second mounting ears to form a plurality of cantilever beam structures, and the L-shaped grooves of two adjacent cantilever beam structures are in opposite directions.

8. The gate mounting structure capable of releasing thermal strain according to claim 7, characterized in that: Acceleration grid mounting interfaces and ion thruster mounting interfaces are evenly distributed along the circumference of the total mounting ring.

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