Large-ratio folded solar sail and spacecraft

Abstract

This invention discloses a high-ratio foldable solar sail and a spacecraft. The high-ratio foldable solar sail includes a solar sail film, a rotation drive device, and a folding drive device. The surface of the solar sail film is a regular polygonal structure with a fixed area at its center. The fixed area is a similar polygon to the outer edge of the solar sail film. The fixed area is equidistantly divided into geometrically similar multi-layered folding areas towards the outer edge of the solar sail film. The diagonals of the solar sail film alternate between mountain folds and valley folds along the multi-layered folding areas. Perpendicular lines are drawn from the vertices of the fixed areas to the outer edge of the solar sail film, also alternating between valley folds and mountain folds along the multi-layered folding areas. The rotation drive device drives the solar sail film to rotate. The folding drive device moves the outer edge of the solar sail film towards or away from the fixed area. The high-ratio foldable solar sail provided by this invention can effectively improve the folding ratio and has high reliability.

Description

Technical Field

[0001] This invention relates to the field of solar sail technology, and in particular, to a high aspect ratio folding solar sail and a spacecraft employing the high aspect ratio folding solar sail. Background Technology

[0002] Solar sail propulsion is a novel propellant-free propulsion mode for spacecraft. Spacecraft equipped with solar sails do not need to carry any energy; they rely solely on the particle nature of light to generate orbital thrust by reflecting sunlight through the large solar sail surface. This effectively eliminates the dependence of traditional spacecraft on limited chemical fuels, making it a key research area in deep space exploration and interstellar travel. Since the thrust generated by a solar sail is positively correlated with its surface area—the larger the surface area, the greater the thrust—the deployment area is constrained by factors such as the solar sail's deployment configuration, the launch vehicle's payload capacity, and the launch vehicle's envelope requirements. Therefore, designing solar sails with a large fold-out ratio while ensuring the smoothness of their deployment process is a crucial task in spacecraft design.

[0003] Traditional solar sails typically employ a Z-shaped folding design. When unfolded, the solar sail is powered by the elastic potential energy of a spring, which drives the spool to rotate, causing the mast to unfold and thus pulling the sail flat. The folding configuration is simple, but the unfolding ratio is limited, and it can only be unfolded at one time. It requires a complex limiting structure, and the limiting unlocking is required during the unfolding process. The structure is complex and lacks versatility, making it impossible to assemble and use on different types of satellites. Summary of the Invention

[0004] The present invention primarily provides a foldable solar sail with a high folding-to-width ratio to solve the technical problems of existing solar sails having a low folding-to-width ratio and complex structure.

[0005] The present invention also provides a spacecraft that employs the aforementioned high aspect ratio folded solar sail.

[0006] According to a first aspect of the present invention, a large folding-to-spread ratio folding solar sail is provided, comprising a solar sail film, a rotation drive device, and a folding-to-spread drive device;

[0007] The surface of the solar sail film is designed as a regular polygon structure. A fixed area is located at the center of the solar sail film. The fixed area is similar to the outer edge of the solar sail film in terms of polygonal shape. The fixed area is divided into geometrically similar multi-layered folded areas at equal intervals along the outer edge of the solar sail film. The diagonal of the solar sail film is designed as alternating mountain folds and valley folds along the multi-layered folded areas. A perpendicular line is drawn from the vertex of the fixed area to the outer edge of the solar sail film. The perpendicular line is designed as alternating valley folds and mountain folds along the multi-layered folded areas. This allows the solar sail film to be folded to form a windmill-shaped first folded state with multiple blades. In the first folded state, the solar sail film can simultaneously shrink multiple blades through rotation to form a petal-shaped second folded state.

[0008] The rotation drive device is connected to the fixed area and is used to drive the solar sail film to rotate.

[0009] The folding and unfolding drive device is connected to multiple vertices on the outer edge of the solar sail film and is used to drive the outer edge of the solar sail film to move in a direction closer to or away from the fixed area;

[0010] When the solar sail film is in the second folded state, the unfolding drive device is used to drive the outer edge of the solar sail film to move away from the fixed area, and the rotation drive device synchronously drives the solar sail film to rotate so that the solar sail film unwinds into the first folded state; when the solar sail film is in the first folded state, the unfolding drive device is used to drive the outer edge of the solar sail film to move away from the fixed area so that the solar sail film unfolds into a regular polygonal structure along multiple folding areas in sequence.

[0011] Preferably, the folding and unfolding drive device includes a housing, a first motor, a reel, multiple expanders, and multiple pod rods. The housing has an inner cavity. The first motor is mounted on the housing. The reel is rotatably mounted in the inner cavity and connected to the first motor. The multiple expanders are arranged equidistantly along the circumference of the housing and communicate with the inner cavity respectively. The multiple pod rods are correspondingly inserted through the multiple expanders. The first end of the pod rod is connected to the reel, and the second end of the pod rod is used to connect to the apex of the solar sail film.

[0012] The expander is used to compress the segment of the pod stalk passing through the expander from a double Ω shape to a flat strip shape as the pod stalk enters the inner cavity. The expander is also used to unfold the segment of the pod stalk passing through the expander from a flat strip shape to a double Ω shape as the pod stalk extends out of the inner cavity.

[0013] The first motor is used to drive the spool to rotate, thereby causing the pod rod to rotate and wrap around the spool or be released from the spool, and then the outer edge of the solar sail film is moved in a direction closer to or away from the fixed area by the pod rod.

[0014] Preferably, two folding and unfolding drive devices are stacked one on top of the other, and the pod stems in the two folding and unfolding drive devices are misaligned circumferentially.

[0015] Preferably, the two folding and unfolding drive devices share a single first motor, which is located between the housings of the two folding and unfolding drive devices.

[0016] Preferably, the folding and unfolding drive device further includes a traction rod, the first end of which is connected to the second end of the pod rod, and the second end of which is connected to the vertex of the solar sail film. The second ends of the traction rods in the two folding and unfolding drive devices are on the same plane.

[0017] Preferably, the folding and unfolding drive device further includes a plurality of pre-tightening components and a plurality of spring-loaded components, wherein the plurality of pre-tightening components are installed one-to-one with one end of the plurality of expanders facing the spool, and the plurality of spring-loaded components are installed one-to-one with one between the pre-tightening components and the spool;

[0018] The pre-tightening assembly includes two pre-tightening rollers disposed on opposite sides of the expander. The two pre-tightening rollers are used to press and straighten the pod stalks together. The spring-loaded assembly is used to spring the pod stalks onto the reel.

[0019] Preferably, the spring-loaded assembly includes a spring post installed in the inner cavity of the housing and an arc-shaped pressure plate connected to the spring post. The arc-shaped pressure plate includes an arc-shaped pressing surface facing the spool. The spring post is used to apply an elastic force in the direction toward the spool to one end of the arc-shaped pressing surface near the pre-tightening assembly.

[0020] Preferably, the rotary drive device includes a support rod, a rotary seat, a second motor, and an angle sensor;

[0021] The first end of the support rod is connected to the folding and unfolding drive device, the rotating seat is rotatably mounted on the second end of the support rod, the rotating seat includes a mounting end face for fixing the fixed area, the second motor is connected to the rotating seat and is used to drive the rotating seat to rotate relative to the support rod, and the angle sensor is provided on the rotating seat and is used to detect the rotation angle of the rotating seat.

[0022] Preferably, the rotary drive device further includes multiple support spokes that are equidistantly arranged around the rotary seat on the outer periphery of the rotary seat and flush with the mounting end face. The support spokes are located on the diagonal line of the solar sail film or on the vertical line and are used to support the solar sail film.

[0023] As a second aspect, the present invention also provides a spacecraft including the aforementioned high aspect ratio folded solar sail.

[0024] The present invention has the following beneficial effects:

[0025] In the large folding ratio folding solar sail provided by the present invention, a fixed area with a similar polygonal shape to the outer edge of the solar sail film is set at the center of the solar sail film. The fixed area is divided into geometrically similar multi-layer folding areas at equal intervals along the outer edge of the solar sail film. The diagonal of the solar sail film is set to alternate between mountain folds and valley folds along the multi-layer folding areas. A perpendicular line is drawn from the vertex of the fixed area to the outer edge of the solar sail film, and the perpendicular line is set to alternate between valley folds and mountain folds along the multi-layer folding areas. This allows the solar sail film to fold along the folding configuration to form a windmill-shaped first folded state with multiple blades. Furthermore, the solar sail film can simultaneously shrink multiple blades to form a petal-shaped second folded state through rotation in the first folded state. Therefore, when the solar sail film is in the second folded state, the outer edge of the solar sail film is moved and unfolded away from the fixed area by the unfolding drive device, and the solar sail film is rotated synchronously by the rotation drive device to unwind the solar sail film into the first folded state; when the solar sail film is in the first folded state, the outer edge of the solar sail film can be moved and unfolded away from the fixed area by the unfolding drive device, so that the solar sail film unfolds into a regular polygonal structure along multiple folding areas in sequence. In summary, this invention optimizes the folding configuration of the solar sail film, enabling multi-stage deployment of the solar sail film through the cooperation of a rotation drive device and a folding drive device. First, the petal-shaped sail surface surrounding the center is stretched outward and straightened, and then the solar sail film is fully unfolded and flattened along the circumference, effectively improving the folding-to-expansion ratio and ensuring the stability of the sail surface folding-to-expansion process. No limiters are required, resulting in a simple, efficient, and highly reliable structure. Furthermore, the reverse action of the rotation drive device and the folding-to-expansion drive device can achieve the shrinking and folding of the solar sail film, thereby enabling multiple controllable folding and unfolding of the solar sail film in orbit, meeting the needs of more application scenarios. Secondly, since this high folding-to-expansion ratio folded solar sail has its own rotation drive device and folding-to-expansion drive device, it can be installed on any satellite platform, making it highly adaptable.

[0026] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0027] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0028] Figure 1 A perspective view of a high-ratio folded solar sail in its second folded state, provided for an embodiment of the present invention.

[0029] Figure 2 for Figure 1 The diagram shows a three-dimensional view of the solar sail with the film removed after folding the solar sail at the shown ratio.

[0030] Figure 3 for Figure 1 The diagram shows the folding ratio of the solar sail in its fully deployed state.

[0031] Figure 4 for Figure 3 The diagram shown is a three-dimensional representation of the folded solar sail at another angle.

[0032] Figure 5 for Figure 1 The diagram shows the unfolding process of the solar sail film when the solar sail is folded.

[0033] Figure 6 for Figure 2 A perspective view of the folding drive mechanism in a folding solar sail, showing the folding ratio.

[0034] Figure 7 for Figure 6 The diagram shows a cross-sectional view of the unfolding drive device.

[0035] Figure 8 for Figure 2 A perspective view of the pod stem in the folding and unfolding drive device shown;

[0036] Figure 9 for Figure 6 A perspective view of the beam expander in the bending and unfolding drive device shown;

[0037] Figure 10 for Figure 6 The diagram shows the operating state of the unfolding drive device, where the arrows indicate the rotation direction during the unfolding process;

[0038] Figure 11 for Figure 2 The diagram shows the structure of the rotation drive device in the folding solar sail.

[0039] Legend:

[0040] 1000. High folding ratio folding solar sail; 1. Solar sail film; 11. Fixing area; 2. Rotation drive device; 21. Support rod; 22. Rotating seat; 23. Second motor; 24. Angle sensor; 25. Controller; 26. Support spokes; 27. Bearing; 3. Folding drive device; 31. Housing; 32. First motor; 33. Reel; 34. Expander; 35. Pod rod; 36. Traction rod; 37. Pretensioning assembly; 371. Pretensioning roller; 38. Spring pressure assembly; 381. Spring column; 382. Arc-shaped pressure plate. Detailed Implementation

[0041] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0042] Figures 1 to 11 The embodiments of the present invention provide a high folding-to-spread ratio folded solar sail, which is used to be installed on spacecraft and uses the particle nature of light to provide propulsion for spacecraft. The folding configuration of the solar sail film is simple and efficient, with a large folding-to-spread ratio, which effectively increases the sail surface area and improves the performance of the solar sail under the same folding volume.

[0043] Please combine Figure 1 , Figure 2 , Figure 3 and Figure 4 The high folding ratio folding solar sail 1000 includes a solar sail film 1, a rotation drive device 2, and a folding drive device 3. The surface of the solar sail film 1 is set as a regular polygon structure. A fixed area 11 is provided at the center of the solar sail film 1. The shape of the fixed area 11 remains unchanged during the folding process of the solar sail film 1, that is, the fixed area 11 does not participate in the folding. The fixed area 11 is a similar polygon concentrically arranged relative to the outer edge of the solar sail film 1. The fixed area 11 is divided into geometrically similar multi-layer folding areas at equal intervals along the fixed area 11 toward the outer edge of the solar sail film 1. Each layer of folding area is arranged around the fixed area 11. The multi-layer folding areas are used to fold in a Z-shape.

[0044] Furthermore, the diagonal of the solar sail film 1 is alternately designed with alternating mountain and valley folds along the multi-layered folded areas. That is, the diagonal of the solar sail film 1 is a mountain fold in the first folded area, a valley fold in the second folded area, a mountain fold in the third folded area, a valley fold in the fourth folded area, and so on, until all folded areas are covered. A perpendicular line is drawn from the vertex of the fixed area 11 to the outer edge of the solar sail film 1. This perpendicular line is also alternately designed with alternating valley and mountain folds along the multi-layered folded areas. Similarly, the perpendicular line is a valley fold in the first folded area, a mountain fold in the second folded area, a valley fold in the third folded area, a mountain fold in the fourth folded area, and so on, until all folded areas are covered. This allows the solar sail film 1 to be folded sequentially along the multi-layer folding area, while also being folded sequentially along the diagonal and the perpendicular line of the solar sail film 1. This enables the solar sail film 1 to fold from a fully unfolded regular polygonal structure into a windmill-shaped first folded state with multiple blades, and allows the solar sail film 1 to simultaneously shrink multiple blades through rotation in the first folded state to form a petal-shaped second folded state.

[0045] Furthermore, the rotation drive device 2 is connected to the fixed area 11 and is used to drive the solar sail film 1 to rotate, and the folding drive device 3 is connected to multiple vertices on the outer edge of the solar sail film 1 and is used to drive the outer edge of the solar sail film to move in a direction closer to or away from the fixed area 11.

[0046] Please combine Figure 5 In the appendix Figure 5 The diagram illustrates six states of the solar sail film 1. According to the arrows, the first state is the second folded state, the fourth state is the first folded state, and the sixth state is the fully unfolded state. The second and third states represent the process of the second folded state retracting into the first folded state, and the fifth state represents the process of the first folded state unfolding into the fully unfolded state. When the solar sail film 1 is in the second folded state, the folding and unfolding drive device 3 moves the outer edge of the solar sail film 1 away from the fixed area 11, and the rotation drive device 2 simultaneously drives the solar sail film 1 to rotate, causing it to retract into the first folded state. When the solar sail film 1 is in the first folded state, the folding and unfolding drive device 3 moves the outer edge of the solar sail film 1 away from the fixed area 11, causing the solar sail film 1 to unfold sequentially into a regular polygonal structure along multiple folding areas.

[0047] In the large folding ratio folding solar sail 1000, a fixed area 11 with a similar polygonal shape to the outer edge of the solar sail film 1 is set at the center of the solar sail film 1. The fixed area 11 is divided into geometrically similar multi-layer folding areas at equal intervals towards the outer edge of the solar sail film 1. The diagonal of the solar sail film 1 is arranged in alternating mountain folds and valley folds along the multi-layer folding areas. A perpendicular line is drawn from the vertex of the fixed area 11 to the outer edge of the solar sail film 1, and the perpendicular line is arranged in alternating valley folds and mountain folds along the multi-layer folding areas. Thus, the solar sail film 1 can fold along its folding configuration to form a windmill-shaped first folded state with multiple blades. Furthermore, the solar sail film 1 can simultaneously shrink multiple blades to form a petal-shaped second folded state through rotation in the first folded state. Therefore, when the solar sail film 1 is in the second folded state, the outer edge of the solar sail film 1 is moved and unfolded away from the fixed area 11 by the unfolding drive device 3, and the solar sail film 1 is rotated synchronously by the rotation drive device 2 to unwind the solar sail film into the first folded state; when the solar sail film 1 is in the first folded state, the outer edge of the solar sail film 1 can be moved and unfolded away from the fixed area 11 by the unfolding drive device 3, so that the solar sail film 1 unfolds into a regular polygonal structure along multiple folding areas in sequence. In summary, by optimizing the folding configuration of the solar sail film 1, this invention enables multi-stage deployment of the solar sail film 1 through the cooperation of the rotation drive device 2 and the folding and unfolding drive device 3. First, the petal-shaped sail surface surrounding the center is stretched outward and straightened, and then the solar sail film 1 is fully unfolded and flattened along the circumference, effectively improving the folding-to-unfold ratio and ensuring the stability of the sail folding and unfolding process. The structure is simple and efficient. Furthermore, the reverse action of the rotation drive device 2 and the folding and unfolding drive device 3 can achieve the shrinking and folding of the solar sail film 1, thereby enabling multiple controllable folding and unfolding of the solar sail film 1 in orbit, meeting more application scenarios. In addition, since the high folding-to-unfold ratio folding solar sail 1000 is equipped with the rotation drive device 2 and the folding and unfolding drive device 3, it can be installed on any satellite platform and is highly adaptable.

[0048] like Figure 6 and Figure 7As shown, the folding and unfolding drive device 3 includes a housing 31, a first motor 32, a reel 33, multiple expanders 34, and multiple pod rods 35. The housing 31 has an inner cavity. The first motor 32 is mounted on the housing 31. The reel 33 is rotatably mounted in the inner cavity and connected to the first motor 32. The multiple expanders 34 are arranged equidistantly along the circumference of the housing 31 and are respectively connected to the inner cavity. The multiple pod rods 35 are correspondingly inserted through the multiple expanders 34. The first end of the pod rod 35 is connected to the reel 33, and the second end of the pod rod 35 is used to connect to the apex of the solar sail film 1.

[0049] Please combine Figure 8 and Figure 9 The pod stalk 35 is made of carbon fiber composite material with shape memory function. One end of the pod stalk 35 is double Ω-shaped, which has high support strength and is not easily bent or deformed. The other end of the pod stalk 35 is flat and strip-shaped, which can be bent and wound around the spool 33. The expander 34 includes a first opening facing away from the spool 33 and a second opening facing the spool 33, as well as an expanding channel connecting the first opening and the second opening and smoothly transitioning between the first opening and the second opening. The first opening is adapted to the double Ω-shaped state of the pod stalk 35, and the second opening is adapted to the flat and strip-shaped state of the pod stalk 35. The expander 34 is used to compress the pod stalk 35 from a double Ω-shaped state to a flat and strip-shaped state through the segments of the expander 34 as the pod stalk 35 enters the inner cavity. The expander 34 is also used to unfurl the pod stalk 35 from a flat and strip-shaped state to a double Ω-shaped state through the segments of the expander 34 as the pod stalk 35 exits the inner cavity.

[0050] Furthermore, the first motor 32 drives the reel 33 to rotate, thereby causing the pod stems 35 to rotate and wind around the reel 33 or be released from the reel 33. The pod stems 35 then drive the outer edge of the solar sail film 1 to move towards or away from the fixed area 11. Through the cooperation of the motor 32 and the reel 33, multiple pod stems 35 can be simultaneously driven to retract or extend relative to the outer shell 31, thereby simultaneously moving multiple vertices of the solar sail film 1, ensuring the synchronous unfolding and folding of the solar sail film 1 in multiple directions. This design is simple and efficient.

[0051] Preferably, two folding and unfolding drive devices 3 are stacked vertically, with the pods 35 of the two folding and unfolding drive devices 3 staggered circumferentially. That is, the pods 35 of one folding and unfolding drive device 3 are located between two adjacent pods 35 of the other folding and unfolding drive device 3. The pods 35 of the two folding and unfolding drive devices 3 support multiple vertices on the outer edge of the solar sail film 1, improving the support strength and avoiding the problem that the roll 33 of a single folding and unfolding drive device 3 cannot simultaneously wind too many pods 35. Moreover, the pods 35 of the other folding and unfolding drive device 3 can provide reinforced support between two adjacent pods 35 of the folding and unfolding drive device 3, resulting in better stress distribution and avoiding stress concentration on the same folding and unfolding drive device 3, thereby improving the stability of the folding and unfolding drive.

[0052] Preferably, the two folding and unfolding drive devices 3 share a single first motor 32. The first motor 32 is located between the housings 31 of the two folding and unfolding drive devices 3. The first motor 32 is connected to the rollers 33 of the two folding and unfolding drive devices 3 respectively through a gearbox, thereby driving the two rollers 33 to rotate simultaneously, ensuring that the rotation speed of the two rollers 33 is synchronized and the rotation angle is consistent, and realizing the synchronous extension and retraction control of all pod stalks 35.

[0053] Preferably, the unfolding drive device 3 further includes multiple traction rods 36, each corresponding to a multiple pod rods 35. The first end of each traction rod 36 is connected to the second end of each pod rod 35, and the second end of each traction rod 36 is connected to the apex of the solar sail film 1. The second ends of the traction rods 36 in the two unfolding drive devices 3 are on the same plane. The pod rods 35 are connected to the solar sail film 1 via the traction rods 36, allowing the unfolding drive device 3 to be positioned entirely on the back of the solar sail film 1, avoiding occupying the front area of ​​the solar sail film 1. Furthermore, it ensures that the second ends of the traction rods 36 in the two unfolding drive devices 3 are on the same plane, enabling the two stacked unfolding drive devices 3 to have the same support height, thus ensuring the complete unfolding of the solar sail film 1.

[0054] In this embodiment, the surface of the solar sail film 1 is designed as a regular hexagonal structure. Each folding and unfolding drive device 3 includes three pods 35, with an included angle of 120 degrees between adjacent pods 35. Thus, the six pods 35 in the two folding and unfolding drive devices 3 support the six vertices of the solar sail film 1 respectively, collectively unfolding the solar sail film 1 with good stability. In other embodiments, the surface of the solar sail film 1 can also be designed as other regular polygonal structures. However, it is worth noting that when the number of vertices of the solar sail film 1 is five or less, it is difficult to stably support the solar sail film 1 using only the traction rods 36 at the vertices, and this will reduce the surface area of ​​the solar sail film 1, affecting the unfolding ratio. Conversely, when the number of vertices of the solar sail film 1 exceeds six, a single folding and unfolding drive device 3 needs to be configured with more than three pods 35. Too many pods 35 are difficult to simultaneously wind onto a single reel 33, requiring a larger diameter reel 33, which increases the size of the folding and unfolding drive device 3 and makes miniaturization difficult.

[0055] Please combine Figure 10 The folding and unfolding drive device 3 further includes a plurality of pre-tightening components 37 and a plurality of spring-loaded components 38 arranged in a one-to-one correspondence with the plurality of pre-tightening components 37. The plurality of pre-tightening components 37 are installed in a one-to-one correspondence at one end of the plurality of expanders 34 facing the spool 33, and the spring-loaded components 38 are installed between the pre-tightening components 37 and the spool 33.

[0056] Furthermore, the pre-tightening assembly 37 includes two pre-tightening rollers 371, which are respectively disposed on opposite sides of the second opening of the expander 34. The two pre-tightening rollers 371 are used to press and straighten the pod stalk 35 against each other, and the spring-loaded assembly 38 is used to spring the pod stalk 35 onto the reel 33. When the pod stalk 35 enters the inner cavity of the housing 31 along the expander 34, the two pre-tightening rollers 371 first apply a pre-tightening force to the pod stalk 35 to pre-tighten and straighten it, preventing the pod stalk 35 from bulging during the retrieval process. Then, the spring-loaded assembly 38 springs the pod stalk 35 onto the reel 33, guiding and constraining the pod stalk 35, effectively preventing problems such as jamming and outward expansion of the pod stalk 35 during the retraction or unfolding process.

[0057] Preferably, the spring-loaded assembly 38 includes a spring post 381 installed in the inner cavity of the housing 31 and an arc-shaped pressure plate 382 connected to the spring post 381. The arc-shaped pressure plate 382 includes an arc-shaped pressing surface facing the spool 33. The arc-shaped pressing surface is arranged along the bending curve of the pod stem 35 at a corresponding position. The spring post 381 applies an elastic force in the direction toward the spool 33 to the end of the arc-shaped pressing surface near the pre-tensioning assembly 37. By pressing the pod stem 35 with the arc-shaped pressing surface of the arc-shaped pressure plate 382, ​​the pod stem 35 is constrained to the spool 33, while the retraction and unfolding of the pod stem 35 can be better guided, guiding the pod stem 35 to wind more smoothly onto the spool 33 or to move more smoothly from the spool 33 to the expander 34.

[0058] like Figure 11 As shown, the rotation drive device 2 includes a support rod 21, a rotating seat 22, a second motor 23, and an angle sensor 24. The first end of the support rod 21 is connected to the folding drive device 3. The rotating seat 22 is rotatably mounted on the second end of the support rod 21. The rotating seat 22 includes a mounting end face 221. The fixing area 11 of the solar sail film 1 is fixedly disposed on the mounting end face 221. The second motor 23 is connected to the rotating seat 22 and is used to drive the rotating seat 22 to rotate relative to the support rod 21, thereby driving the solar sail film 1 as a whole to rotate relative to the folding drive device 3. The angle sensor 24 is disposed on the rotating seat 22 and is used to detect the rotation angle of the rotating seat 22 to ensure that the solar sail film 1 is folded in place and to avoid the solar sail film 1 from rotating too much or too little, resulting in wrinkles and failure to fully unfold.

[0059] Furthermore, the rotary drive device 2 also includes a controller 25, with the second motor 23 and the angle sensor 24 electrically connected to the controller 25 respectively. The controller 25 is used to adjust the rotational action of the second motor 23 in real time according to the detection result of the angle sensor 24, thereby improving the rotary drive accuracy.

[0060] Preferably, the rotary drive device 2 further includes multiple support spokes 26 equidistantly arranged around the outer periphery of the rotary base 22, with the upper surface of each support spoke 26 flush with the mounting end face 221. A perpendicular line is drawn from the apex of the fixing area 11 to the outer edge of the solar sail film 1; the multiple support spokes 26 are correspondingly arranged along this perpendicular line and support the solar sail film 1. The rotary drive device 2 strengthens the support of the solar sail film 1 through the multiple support spokes 26, improving the stability of the solar sail film 1, thereby reducing the area of ​​the mounting end face 221, and consequently reducing the volume and weight of the rotary base 22, thus improving its applicability.

[0061] In other embodiments, the support spokes 26 may also be located on the diagonal of the solar sail film 1, that is, multiple support spokes 26 are arranged one-to-one with multiple diagonals of the solar sail film 1, which can also stably support the fixed area 11 and improve the stability of the solar sail film 1.

[0062] Furthermore, the rotary drive device 2 also includes a bearing 27 disposed between the support rod 21 and the rotary seat 22, which improves the smoothness of the rotation of the rotary seat 22 on the support rod 21 and avoids jamming.

[0063] As a second aspect, the present invention also provides a spacecraft including the aforementioned high folding-to-spread ratio foldable solar sail 1000. Since the folding configuration of the high folding-to-spread ratio foldable solar sail 1000 can effectively improve the folding-to-spread ratio, the structure is simple and efficient, the reliability is high, and the solar sail film 1 can be folded and unfolded multiple times in orbit in a controllable manner. This effectively improves the thrust performance of the spacecraft within the limited space of the spacecraft, enabling the spacecraft to meet more application scenarios and has strong applicability.

[0064] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A high-ratio folding solar sail, characterized in that, It includes a solar sail film (1), a rotation drive device (2), and a folding drive device (3); The surface of the solar sail film (1) is set as a regular polygon structure. A fixed area (11) is provided at the center of the solar sail film (1). The fixed area (11) is similar to the outer edge of the solar sail film (1). The fixed area (11) is divided into geometrically similar multi-layer folded areas at equal intervals along the outer edge of the solar sail film (1). The diagonal of the solar sail film (1) is set as alternating mountain folds and valley folds along the multi-layer folded areas. A perpendicular line is drawn from the vertex of the fixed area (11) to the outer edge of the solar sail film (1). The perpendicular line is set as alternating valley folds and mountain folds along the multi-layer folded areas. This allows the solar sail film (1) to be folded to form a windmill-shaped first folded state with multiple blades. The solar sail film (1) can also be folded to form a petal-shaped second folded state by rotating in the first folded state by simultaneously shrinking multiple blades. The rotation drive device (2) is connected to the fixed area (11) and is used to drive the solar sail film (1) to rotate. The rotation drive device (2) includes an angle sensor (24) and a controller (25). The angle sensor (24) is used to detect the rotation angle of the solar sail film (1), and the controller (25) is used to adjust the rotation action of the solar sail film (1) in real time according to the detection result of the angle sensor (24). The folding and unfolding drive device (3) is connected to multiple vertices on the outer edge of the solar sail film (1) and is used to drive the outer edge of the solar sail film (1) to move in a direction closer to or further away from the fixed area (11); When the solar sail film (1) is in the second folded state, the unfolding drive device (3) is used to drive the outer edge of the solar sail film (1) to move away from the fixed area (11), and the rotation drive device (2) synchronously drives the solar sail film (1) to rotate so that the solar sail film (1) is unfurled into the first folded state; when the solar sail film (1) is in the first folded state, the unfolding drive device (3) is used to drive the outer edge of the solar sail film (1) to move away from the fixed area (11) so that the solar sail film (1) unfolds into a regular polygonal structure along multiple folding areas.

2. The high folding-ratio folding solar sail according to claim 1, characterized in that, The folding and unfolding drive device (3) includes a housing (31), a first motor (32), a reel (33), multiple expanders (34) and multiple pod rods (35). The housing (31) has an inner cavity. The first motor (32) is mounted on the housing (31). The reel (33) is rotatably mounted in the inner cavity and connected to the first motor (32). Multiple expanders (34) are arranged equidistantly along the circumference of the housing (31) and communicate with the inner cavity respectively. Multiple pod rods (35) are correspondingly inserted on multiple expanders (34). The first end of the pod rod (35) is connected to the reel (33), and the second end of the pod rod (35) is used to connect to the vertex of the solar sail film (1). The expander (34) is used to compress the segment of the pod stalk (35) through the expander (34) from a double Ω shape to a flat strip shape as the pod stalk (35) enters the inner cavity. The expander (34) is also used to expand the segment of the pod stalk (35) through the expander (34) from a flat strip shape to a double Ω shape as the pod stalk (35) extends out of the inner cavity. The first motor (32) is used to drive the spool (33) to rotate, thereby causing the pod rod (35) to rotate and wrap around the spool (33) or be released from the spool (33), and then the outer edge of the solar sail film (1) is moved along the direction closer to or away from the fixed area (11) by the pod rod (35).

3. The high folding-to-width ratio folding solar sail according to claim 2, characterized in that, Two folding and unfolding drive devices (3) are stacked on top of each other, and the pod stems (35) in the two folding and unfolding drive devices (3) are misaligned in the circumferential direction.

4. The high folding-ratio folding solar sail according to claim 3, characterized in that, The two folding drive devices (3) share a single first motor (32), which is located between the housings (31) of the two folding drive devices (3).

5. The high folding-ratio folding solar sail according to claim 3, characterized in that, The folding and unfolding drive device (3) also includes a traction rod (36), the first end of which is connected to the second end of the pod rod (35), and the second end of which is connected to the vertex of the solar sail film (1). The second ends of the traction rods (36) in the two folding and unfolding drive devices (3) are on the same plane.

6. The high folding-ratio folding solar sail according to claim 2, characterized in that, The folding and unfolding drive device (3) further includes multiple pre-tightening components (37) and multiple spring-loaded components (38). The multiple pre-tightening components (37) are installed one-to-one with one end of multiple expanders (34) facing the spool (33), and the multiple spring-loaded components (38) are installed one-to-one with one between the pre-tightening components (37) and the spool (33). The pre-tightening assembly (37) includes two pre-tightening rollers (371) disposed on opposite sides of the expander (34). The two pre-tightening rollers (371) are used to press and straighten the pod stalk (35) against each other. The spring-loaded assembly (38) is used to spring the pod stalk (35) onto the reel (33).

7. The high folding-ratio folding solar sail according to claim 6, characterized in that, The spring-loaded assembly (38) includes a spring post (381) installed in the inner cavity of the housing (31) and an arc-shaped pressure plate (382) connected to the spring post (381). The arc-shaped pressure plate (382) includes an arc-shaped pressing surface disposed toward the spool (33). The spring post (381) is used to apply an elastic force in the direction toward the spool (33) to one end of the arc-shaped pressing surface near the pre-tightening assembly (37).

8. The high folding-ratio folding solar sail according to claim 1, characterized in that, The rotary drive device (2) includes a support rod (21), a rotary seat (22), and a second motor (23); The first end of the support rod (21) is connected to the folding drive device (3), the rotating seat (22) is rotatably mounted on the second end of the support rod (21), the rotating seat (22) includes a mounting end face (221) for fixing the fixing area (11), the second motor (23) is connected to the rotating seat (22) and is used to drive the rotating seat (22) to rotate relative to the support rod (21), and the angle sensor (24) is provided on the rotating seat (22) and is used to detect the rotation angle of the rotating seat (22).

9. The high folding ratio folding solar sail according to claim 8, characterized in that, The rotary drive device (2) further includes multiple support spokes (26) that are equidistantly arranged around the rotary seat (22) on the outer periphery of the rotary seat (22) and flush with the mounting end face (221). The support spokes (26) are located on the diagonal line of the solar sail film (1) or on the vertical line and are used to support the solar sail film (1).

10. A spacecraft, characterized in that, Including a high-ratio folding solar sail as described in any one of claims 1 to 9.

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