Load-bearing cylinder structure of long focal length coaxial space camera

Abstract

The present invention relates to the field of space optical remote sensing technology, and in particular to a load-bearing cylinder structure for a long-focal-length coaxial space camera, comprising: a cylinder, T-shaped ring ribs, and a front frame. The cylinder is divided into a main body region, a bottom thickened region, and a top thickened region; the T-shaped ring ribs are evenly distributed axially along the main body region; and the front frame is embedded in the top thickened region. The advantage of the present invention is that the load-bearing cylinder is made of carbon fiber composite material, wherein the cylinder is a thin-walled structure. Under the same volume conditions, the overall isostatic stiffness (deformation under a force of 500kg) is equivalent to that of titanium alloy, while the weight is reduced by 63%. Through the layered structure of the cylinder, T-shaped ring ribs, and front frame, the linear expansion coefficients of the connection parts are adapted to avoid stress concentration.

Description

Technical Field

[0001] The present invention relates to the technical field of space optical remote sensing, and in particular to a bearing cylinder structure of a long-focal-length coaxial space camera. Background Art

[0002] Long-focal-length coaxial space cameras are core equipment for deep space exploration and high-resolution Earth observation. Their optical system typically consists of a primary mirror, a secondary mirror, a tertiary mirror, and a detector. These mirrors are typically mounted on a base at the bottom of the camera, while the secondary mirror is mounted on a radial support beam at the top. The two require a body for connection and load transfer. The base and radial support beams are key components of the camera, ensuring a stable and reliable spatial relationship between the primary and secondary mirrors, thereby ensuring image quality.

[0003] There are two common fuselage configurations: truss structures and thin-walled load-bearing tube structures. Load-bearing tube structures are widely used in space cameras due to their advantages such as high stiffness, high strength, and high thermal stability. However, traditional load-bearing tubes are mostly made of metal materials (such as aluminum alloys and titanium alloys) and reinforced with evenly spaced circular or longitudinal reinforcements. This design has the following problems:

[0004] Excessive weight: Metal materials have high density, and thick-walled or dense rib designs cannot meet lightweight requirements.

[0005] Sensitive to thermal deformation: The coefficient of linear expansion (CTE) of metal materials is high, and spatial temperature changes can easily cause optical axis deviation. Summary of the Invention

[0006] In light of this, the present invention aims to provide a supporting tube structure for a long-focal-length coaxial space camera. The supporting tube is manufactured using a carbon fiber composite material through a winding molding process, effectively reducing its weight. The design of the tube, T-shaped ring ribs, and the layup of the front frame can avoid thermal stress caused by temperature changes.

[0007] To achieve the above-mentioned purpose, the technical solution created by the present invention is implemented as follows: a long-focal-length coaxial space camera load-bearing cylinder structure, comprising: a cylinder body, the cylinder body including a top thickened area, a main body area and a bottom thickened area distributed along the axial direction; T-shaped ring ribs, the T-shaped ring ribs are evenly distributed axially along the inner wall of the main body area; and a front frame, the front frame is embedded in the top thickened area.

[0008] Furthermore, the main body area is conical; the top thickened area extends gradually axially upward from the top of the main body area, and the wall thickness of the top thickened area increases along the extension direction; the bottom thickened area extends gradually axially downward from the bottom of the main body area, and the wall thickness of the bottom thickened area increases along the extension direction.

[0009] Furthermore, the cylinder, T-shaped ring ribs and front frame are all formed by winding carbon fiber composite materials.

[0010] Furthermore, the ply structure of the main body area is [90 / +54 / 0 / -54 / 90]2s; the ply structure of the bottom thickened area is [90 / +54 / 0 / -54 / 90 / 0 / 90 / 0 / +54 / 0 / -54 / 0 / 90]s; and the ply structure of the top thickened area is [903 / +54 / 0 / -54 / 903 / +54 / 0 / -54 / 90] s .

[0011] Furthermore, the layup structure of the T-shaped ring reinforcement is [90 / +54 / 0 / -54 / 90]3.

[0012] Furthermore, the ply structure of the front frame is [90 / +45 / 90 / -45 / 90]8.

[0013] Furthermore, the T-shaped ring rib includes a cylindrical base and a reinforcing rib extending radially inward along the inner wall of the cylindrical base, and the radial width of the reinforcing rib is 2 to 3 times the height of the cylindrical base.

[0014] Furthermore, the distance between two adjacent T-shaped ring ribs is 1 / 10 to 1 / 5 of the diameter of the cylindrical base.

[0015] Furthermore, the front frame includes a C-shaped frame and radial ribs, and the radial ribs are radially and evenly distributed in the C-shaped frame.

[0016] Furthermore, the number of the radiation ribs is 6 to 12.

[0017] The invention can achieve the following beneficial effects:

[0018] 1) Lightweight design: The bearing cylinder of the present invention is made of carbon fiber composite material, with a thin-walled cylinder structure and T-shaped ring reinforcement ribs. This makes the overall static stiffness (deformation under a force of 500kg) of the bearing cylinder equivalent to that of titanium alloy under the same volume conditions, while reducing the weight by 63%;

[0019] 2) Low overload stress: Under overload conditions, the Tsai-Wu failure criterion evaluation value (Tsai-Wu value) of the bearing cylinder is less than 0.1, meeting high reliability requirements.

[0020] 3) Low thermal stress: Within the operating temperature range, the Tsai-Wu value of the connection area between the cylinder and the front frame is less than 0.02, effectively avoiding the risk of failure caused by thermal stress.

[0021] 4) Good processability: The structural molding process is simple, easy to assemble, and suitable for mass production.

[0022] 5) Through the lay-up structure of the cylinder, T-shaped ring reinforcement and front frame, the linear expansion coefficients of the connection parts are adapted to avoid stress concentration.

[0023] 6) The T-shaped ring ribs have both structural reinforcement and aperture functions, which improves the rigidity while meeting the light-shielding requirements of the optical system. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0025] Figure 1 is an axial cross-sectional view of a bearing cylinder structure of a long-focal-length coaxial space camera provided according to an embodiment of the present invention;

[0026] Figure 2 According to an embodiment of the present invention, Figure 1 A partial enlarged view of point A in the middle (the connection between the barrel and the front frame);

[0027] Figure 3 According to an embodiment of the present invention, Figure 1 A partial enlarged view of point B in the middle (the connection between the cylinder and the T-shaped ring reinforcement);

[0028] Figure 4 is an axial cross-sectional view of a cylinder provided according to an embodiment of the present invention;

[0029] Figure 5 According to an embodiment of the present invention, Figure 4 A partial enlarged view of point C (top thickened area);

[0030] Figure 6 According to an embodiment of the present invention, Figure 4 A partial enlarged view of point D (bottom thickened area);

[0031] Figure 7 is an axial cross-sectional view of a T-shaped ring rib provided according to an embodiment of the present invention;

[0032] Figure 8 is an axial cross-sectional view of a front frame provided according to an embodiment of the present invention;

[0033] Figure 9 According to an embodiment of the present invention, Figure 8 Cross-sectional view along EE.

[0034] The reference numerals include: 1. cylinder; 11. main body area; 12. top thickened area; 13. bottom thickened area; 2. T-shaped ring rib; 21. cylindrical base; 22. reinforcing rib; 3. front frame; 31. C-shaped frame; 32. radial rib. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation of the present invention.

[0036] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0037] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second" and the like are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, features defined as "first", "second" and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0038] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art can understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0039] The present invention will be described in detail below with reference to the embodiments.

[0040] like Figures 1 to 9 As shown, an embodiment of the present invention provides a load-bearing cylinder structure for a long-focal-length coaxial space camera, comprising: a cylinder 1, T-shaped ring ribs 2, and a front frame 3. The T-shaped ring ribs 2 are evenly distributed along the inner wall of the cylinder 1 along its axial direction, and the front frame 3 is embedded in the top of the cylinder 1. The cylinder 1, T-shaped ring ribs 2, and front frame 3 are all formed by winding carbon fiber composite materials.

[0041] The cylinder 1 is divided into a main body region 11, a top thickened region 12, and a bottom thickened region 13. The main body region 11 is conical in shape, with a wall thickness of 2 mm. The top thickened region 12 extends axially upward from the top of the main body region 11, with the wall thickness increasing along the extension direction. The bottom thickened region 13 extends axially downward from the bottom of the main body region 11, with the wall thickness increasing along the extension direction.

[0042] Specifically, the main body area 11 is a low axial linear expansion area, and the ply structure of the main body area 11 is [90 / +54 / 0 / -54 / 90]2s. This ply design can effectively suppress axial thermal deformation, thereby ensuring that the primary mirror and secondary mirror of the space camera maintain a stable relative position relationship when the temperature changes.

[0043] The top thickened area 12 connects to the front frame 3. Its ply structure is [903 / +54 / 0 / -54 / 903 / +54 / 0 / -54 / 90]s, matching the radial linear expansion coefficient of the front frame 3 and preventing stress concentration. This ply structure regulates thermal stress distribution during temperature fluctuations, improving structural reliability.

[0044] The bottom thickened area 13 connects to the space camera's metal base. Its ply structure is [90 / +54 / 0 / -54 / 90 / 0 / 90 / 0 / +54 / 0 / -54 / 0 / 90]s, matching the radial linear expansion coefficient of the metal base and avoiding stress concentration. This ply structure regulates thermal stress distribution during temperature fluctuations, improving structural reliability.

[0045] The T-shaped ring rib 2 includes a cylindrical base 21 and a reinforcing rib 22 extending radially inward along the inner wall of the cylindrical base 21. The radial width of the reinforcing rib 22 is 2 to 3 times the height of the cylindrical base 21. The spacing between two adjacent T-shaped ring ribs 2 is 1 / 10 to 1 / 5 of the diameter of the cylindrical base 21. While satisfying the requirement of reinforcing rigidity, the T-shaped ring rib 2 also has the function of a diaphragm. The T-shaped ring rib 2 and the main body 11 are connected by a composite connection of adhesive and screws. The composite screw connection is a hybrid connection method that combines adhesive bonding and mechanical fastening with bolts / screws, combining the advantages of both. It is often used in structures with high requirements for connection strength, sealing, and fatigue resistance.

[0046] The number of the T-shaped ring ribs 2 is 3-6. In this embodiment, the number of the T-shaped ring ribs 2 is 4.

[0047] The ply structure of the T-shaped ring reinforcement 2 is [90 / +54 / 0 / -54 / 90]3, so as to ensure that the radial linear expansion coefficient of the T-shaped ring reinforcement 2 is compatible with the radial linear expansion coefficient of the main body area 11.

[0048] The front frame 3 includes a C-shaped frame 31 and radial ribs 32, which are evenly distributed radially within the C-shaped frame 31. The number of radial ribs 32 ranges from 6 to 12. In this embodiment, there are 12 radial ribs 32. The C-shaped frame 31 is connected to the top thickened area 12 with a composite screw connection.

[0049] The ply structure of the front frame 3 is [90 / +45 / 90 / −45 / 90] 8 to ensure that the radial linear expansion coefficient of the front frame 3 is compatible with the radial linear expansion coefficient of the top thickened area 12 .

[0050] Specifically, the C-shaped frame 31 includes a cylinder and two rings, which are respectively connected to the two ends of the cylinder. The radiating ribs 32 are rectangular plates. The radiating ribs 32 are evenly distributed radially between the two rings along the circumference of the ring, and one long side of each radiating rib 32 is connected to the inner wall of the cylinder, and the other two short sides are respectively connected to the two rings.

[0051] Mechanical load analysis:

[0052] Finite element simulation software was used to apply an overload load of 10 times gravity to the bearing cylinder in three mutually perpendicular directions. The simulation results showed that the Tsai-Wu (Tsai-Wu Failure Criterion) failure criterion value of the bearing cylinder was less than 0.1 under each condition.

[0053] Thermal load analysis:

[0054] Under the condition of uniform temperature rise of +5℃, finite element analysis shows that the Tsai-Wu value of the connection area between the bearing cylinder and the metal base is less than 0.02.

[0055] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A bearing cylinder structure for a long focal length coaxial space camera, characterized in that: include: A cylinder, the cylinder comprising a top thickened area, a main body area and a bottom thickened area distributed along the axial direction; T-shaped ring ribs, the T-shaped ring ribs being evenly distributed axially along the inner wall of the main body area; a front frame, the front frame being embedded in the top thickened area; The cylinder, T-shaped ring ribs and the front frame are all formed by winding carbon fiber composite materials; The ply structure of the main area is [90 / +54 / 0 / -54 / 90]2s; the ply structure of the bottom thickened area is [90 / +54 / 0 / -54 / 90 / 0 / 90 / 0 / +54 / 0 / -54 / 0 / 90]s; the ply structure of the top thickened area is [903 / +54 / 0 / -54 / 903 / +54 / 0 / -54 / 90]s.

2. The bearing cylinder structure of the long focal length coaxial space camera according to claim 1, characterized in that: The main body area is conical; the top thickened area extends gradually upward along the axial direction from the top of the main body area, and the wall thickness of the top thickened area increases along the extension direction; the bottom thickened area extends gradually downward along the axial direction from the bottom of the main body area, and the wall thickness of the bottom thickened area increases along the extension direction.

3. The bearing cylinder structure of the long focal length coaxial space camera according to claim 1, characterized in that: The ply structure of the T-shaped ring reinforcement is [90 / +54 / 0 / -54 / 90]3.

4. The bearing cylinder structure of the long focal length coaxial space camera according to claim 1, characterized in that: The ply structure of the front frame is [90 / +45 / 90 / -45 / 90]8.

5. The bearing cylinder structure of the long focal length coaxial space camera according to claim 1, characterized in that: The T-shaped ring rib includes a cylindrical base and a reinforcing rib extending radially inward along the inner wall of the cylindrical base. The radial width of the reinforcing rib is 2 to 3 times the height of the cylindrical base.

6. The bearing cylinder structure of the long focal length coaxial space camera according to claim 5, characterized in that: The distance between two adjacent T-shaped ring ribs is 1 / 10 to 1 / 5 of the diameter of the cylindrical base.

7. The bearing cylinder structure of the long focal length coaxial space camera according to claim 1, characterized in that: The front frame includes a C-shaped frame and radiation ribs, and the radiation ribs are radially and evenly distributed in the C-shaped frame.

8. The bearing cylinder structure of the long focal length coaxial space camera according to claim 7, characterized in that: The number of the radiation ribs is 6 to 12.

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