A wrapable stowable cassegrain antenna

Abstract

The application discloses a kind of wrapable storage Cassegrain antenna, including main reflector, secondary reflector, feed, feed telescopic mechanism and main mounting ring, the flexible rib root of main reflector is hinged to main mounting ring, can be synchronously turned down to preset storage angle and then be wound, and be constrained to be unfolded by the shell cover of the top end of feed telescopic mechanism;Feed telescopic mechanism is equipped with electrically controllable unlocking locking device, after unlocking, automatically extend and drive shell cover to separate, and flexible rib relies on pre-stored strain energy and automatically unfolds and locks.The application uses the storage mode of first pressing and then winding, realizes ultra-high storage ratio, high system integration, strong reliability, and adapts to the strict restrictions of micro-satellite platform.

Description

Technical Field

[0001] This invention relates to a windable and retractable Cassegrain antenna. Background Technology

[0002] The Cassegrain antenna consists of a main reflector, a sub-reflector, and a feed. It utilizes the focal conjugate characteristic of the hyperboloid sub-reflector to convert the spherical wave radiated by the feed into a plane wave emitted along the parabolic axis. It has high gain, low sidelobes, and good directivity, and is widely used in satellite communication, deep space exploration, and aerospace telemetry and control.

[0003] As spacecraft increasingly demand lighter and more compact payloads, traditional rigid Cassegrain antennas, due to their large size and inability to be folded and stored, are difficult to fit into the limited fairing space of launch vehicles, severely restricting the on-orbit deployment capability of large antennas.

[0004] Existing deployable antennas mostly employ multi-joint rigid hinge deployment mechanisms or inflatable support structures. The former has a large number of parts and a complex mechanism, resulting in low reliability during deployment, and the accumulation of hinge gaps can easily lead to surface errors in the reflector. The latter relies on airtightness to maintain its configuration, which poses a risk of gas leakage, and the surface accuracy after deployment is difficult to guarantee.

[0005] While some umbrella-shaped antennas employing flexible rib frames can achieve radial folding, the flexible ribs still occupy a significant amount of space axially during storage, and they lack an integrated mechanism for simultaneously compressing and storing the feed, sub-reflector, and main reflector axially. Furthermore, after retracting on the ground, such antennas require a reliable holding mechanism to maintain the retracted state and resist vibration overload during transmission; and once in outer space, they need to be able to automatically release and deploy in one go in response to remote control commands. Existing structures struggle to simultaneously meet the requirements of reliable ground holding and automatic one-time deployment in orbit. Summary of the Invention

[0006] The present invention provides a windable and retractable Cassegrain antenna to solve the problems existing in the prior art.

[0007] The technical solutions adopted in this invention are as follows:

[0008] A windable and retractable Cassegrain antenna includes a main reflector, a sub-reflector, and a feed, and also includes a feed telescopic mechanism and a main mounting ring;

[0009] The bottom end of the feed telescopic mechanism is fixedly connected to the main mounting ring, and the top end is fixed with a cover;

[0010] Both the feed source and the sub-reflector are fixed on the feed source telescopic mechanism;

[0011] The main reflective surface includes a metal reflective mesh and multiple flexible ribs. The metal reflective mesh is fixed on all the flexible ribs. The root of each flexible rib is hinged to the outer circumference of the main mounting ring. All the flexible ribs can rotate synchronously downward around the hinge axis to a preset storage angle.

[0012] At the preset storage angle, all flexible ribs can be wrapped around the outside of the main mounting ring, and the shell is used to cover the wrapped flexible ribs to restrain their unfolding;

[0013] The feed telescopic mechanism is equipped with an electrically unlockable locking device for limiting the feed telescopic mechanism to maintain a retracted state. After the locking device is unlocked, the feed telescopic mechanism automatically extends along the axial direction and drives the shell to disengage from the flexible rib. After the flexible rib is unrestrained, it automatically unfolds and locks to a preset working angle.

[0014] Furthermore, the feed telescopic mechanism includes multiple coaxially arranged retainers, at least three elastic telescopic members, and a connecting seat.

[0015] The elastic telescopic components are evenly distributed along the circumference of the retainer, and multiple retainers are fixedly fixed to the elastic telescopic components at axial intervals. The connecting seat is fixedly connected to the bottommost retainer, and the main mounting ring is fixedly connected to the connecting seat.

[0016] Furthermore, the feed source is fixed on one of the holders and is coaxial with the holder, and the sub-reflector and the housing are both fixed on the topmost holder.

[0017] Furthermore, the locking device includes a take-up reel, at least one wire rope, and an electric limiter with a telescopic head. The wire rope passes through all the retainers, with its top end fixed to the topmost retainer and its bottom end wound around the take-up reel. The take-up reel is rotatably connected to the bottommost retainer, and the electric limiter is fixed to the bottommost retainer. The telescopic head of the electric limiter extends out to constrain the rotation of the take-up reel.

[0018] Furthermore, the electric limiter is a shape memory alloy pin puller, which has a pin hole on the take-up reel. The retractable pin in the shape memory alloy pin puller is inserted into the pin hole to lock the take-up reel.

[0019] Furthermore, adjacent retainers are engaged by a locating pin, which is vertically fixed to the retainer. The locating pin has a through hole at its axis, and the locating pin on the lower retainer is inserted into the through hole of the locating pin on the upper retainer.

[0020] Furthermore, the elastic stretching component is made of aramid fiber.

[0021] Furthermore, the outer circumferential wall of the main mounting ring is provided with multiple toothed grooves, each toothed groove having a bottom surface and a side surface, and a mounting block is hinged to the bottom surface of each toothed groove, with the root of each flexible rib fixed to a mounting block.

[0022] Furthermore, all mounting blocks are linked together by a synchronous transmission mechanism to achieve synchronous rotation of all mounting blocks.

[0023] Furthermore, the synchronous transmission mechanism includes multiple linkage gears, which are disposed on the inner side of the main mounting ring. Each linkage gear is fixedly connected to a mounting block via a rotating shaft, which is rotatably connected to the main mounting ring. All linkage gears mesh with each other in sequence.

[0024] Furthermore, each mounting block is provided with a first arc groove, and the bottom surface of each toothed groove is provided with a second arc groove. The first arc groove and the second arc groove can be spliced ​​together to form a complete circular groove. A pin can be inserted into the circular groove to temporarily lock the mounting block at a preset storage angle.

[0025] Furthermore, a reset spring is provided between the side of each tooth groove and the corresponding mounting block, with one end of the reset spring abutting against the side of the tooth groove and the other end abutting against the mounting block.

[0026] Furthermore, the mounting block is provided with an abutment head, which can abut against the side of the tooth groove to limit the maximum angle of upward rotation of the mounting block.

[0027] Furthermore, the inner end face of the main mounting ring is provided with a plurality of mounting holes, in which spring pins are installed. Each mounting block is provided with a limiting hole that matches the spring pin. The spring pin can be inserted into the limiting hole to finally lock the mounting block at the position of the preset working angle.

[0028] Furthermore, the mounting block is provided with a mounting groove that matches the shape of the flexible rib, the flexible rib is inserted into the mounting groove, and the flexible rib is fixed to the mounting block by bolts.

[0029] Furthermore, the cross-section of the flexible rib is pod-shaped.

[0030] Furthermore, the flexible rib is made of carbon fiber.

[0031] The present invention has the following beneficial effects:

[0032] This application utilizes the rotation of the main mounting ring to wind and store the flexible ribs, while simultaneously using the axial contraction of the feed telescopic mechanism to drive the shell to cover and constrain the wound flexible ribs. This achieves synchronous axial compression and storage of the main reflector, feed, and sub-reflector, significantly reducing the axial and radial envelope dimensions during launch and effectively adapting to the spatial constraints of the launch vehicle fairing.

[0033] This application features an electrically unlockable locking device on the feed telescopic mechanism. After retraction is completed on the ground, the device reliably maintains its retracted state to resist vibration overload during the launch phase. Once in outer space, it is automatically unlocked in one go via remote control command. The device utilizes the elasticity of the flexible ribs and the automatic extension of the feed telescopic mechanism to achieve on-orbit deployment without human intervention. The structure is simple, has few parts, and has high deployment reliability.

[0034] The main reflective surface of this application adopts a combination structure of flexible ribs and metal reflective mesh. The flexible ribs have both the flexibility to be stored and the structural rigidity after being deployed, eliminating the need for a complex inflation or hinge deployment mechanism, thus balancing compact storage and reliable deployment.

[0035] This application uses a locking mechanism to limit the flexible ribs to a preset working angle after they are deployed, and works in conjunction with the shell to release the constraint, ensuring the stability of the skeleton structure after deployment and providing a structural benchmark for the surface accuracy of the reflective surface. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the overall structure of the windable and retractable Cassegrain antenna of the present invention;

[0037] Figure 2 This is a schematic diagram of the feed extension mechanism of the present invention in its deployed state;

[0038] Figure 3 This is a schematic diagram of the feed extension mechanism of the present invention from another perspective in its deployed state;

[0039] Figure 4 This is a schematic diagram of the feed extension mechanism of the present invention in its retracted state;

[0040] Figure 5 This is a partial structural schematic diagram of the feed extension mechanism of the present invention in its retracted state;

[0041] Figure 6 This is a schematic diagram of the assembly of the take-up reel and the pin puller of the present invention on the bottommost retainer.

[0042] Figure 7 A schematic diagram of the structure of the take-up reel and the pin puller;

[0043] Figure 8 This is a schematic diagram of the feed extension mechanism of the present invention after it has been retracted;

[0044] Figure 9 This is a schematic diagram of the feed extension mechanism of the present invention after it has been retracted;

[0045] Figure 10 This is a schematic diagram of the umbrella-shaped structure of the main reflective surface of the present invention;

[0046] Figure 11This is a partial structural diagram of the mounting block and the main mounting ring of the present invention.

[0047] Figure 12 This is a partially enlarged schematic diagram of the mounting block limiting structure of the present invention;

[0048] Figure 13 This is a schematic diagram of the structure of the reset spring and the mounting block of the present invention.

[0049] Figure 14 This is a schematic diagram showing the state of the mounting block after the skeleton of the present invention has been fully released;

[0050] Figure 15 This is a schematic diagram showing the state of the mounting block after the frame of the present invention has been pressed down and rotated.

[0051] Figure 16 This is a schematic diagram comparing the expanded state and the retracted state of the skeleton of the present invention. Detailed Implementation

[0052] The invention will now be further described with reference to the accompanying drawings.

[0053] To make the technical solution, structural features, and working principle of this application clearer and more complete, the following detailed description is provided in conjunction with the accompanying drawings. It should be noted that the directional terms used in this application, such as top, bottom, upper end, lower end, inner side, and outer side, are all based on the vertical direction of the antenna when it is deployed and in use on the ground.

[0054] like Figure 1 This application discloses a windable and retractable Cassegrain antenna, including a main reflector 11, a sub-reflector 12, a feed 13, a feed telescopic mechanism 2, and a main mounting ring 31.

[0055] The main reflector 11 has an umbrella-shaped structure, including a metal reflector mesh 111 and multiple flexible ribs 112. The metal reflector mesh 111 is fixed on all the flexible ribs 112, which together form a parabolic working surface for reflecting electromagnetic waves. The secondary reflector 12 is a hyperboloid reflector made of copper. The feed source 13 is used to radiate electromagnetic waves to the secondary reflector 12.

[0056] The bottom end of the feed telescopic mechanism 2 is fixedly connected to the main mounting ring 31, and the top end is fixed with a cover 24. The feed 13 and the sub-reflector 12 are both fixed on the feed telescopic mechanism 2.

[0057] In the main reflective surface 11, the root of each flexible rib 112 is hinged to the outer circumference of the main mounting ring 31, and all flexible ribs 112 can synchronously rotate downward around the hinge axis to a preset retracted angle. At the preset retracted angle, all flexible ribs 112 can be wrapped around the outside of the main mounting ring 31. The cover 24 is used to cover the wrapped flexible ribs 112 to constrain their unfolding.

[0058] The feed telescopic mechanism 2 is equipped with an electrically unlockable locking device for limiting the feed telescopic mechanism 2 to maintain its retracted state. After the locking device is unlocked, the feed telescopic mechanism 2 automatically extends along the axial direction and drives the housing 24 to disengage from the flexible rib 112. After the flexible rib 112 is unrestrained, it automatically unfolds and locks to a preset working angle.

[0059] like Figures 2 to 5 The feed telescopic mechanism 2 includes multiple coaxially arranged retainers 21, at least three elastic telescopic members 22, and a connecting seat 23. The elastic telescopic members 22 are evenly distributed circumferentially along the retainers 21. In this embodiment, there are three elastic telescopic members 22, arranged at 120-degree intervals circumferentially to ensure structural stability and uniform force distribution during the telescopic process. The multiple retainers 21 are fixed at intervals on the elastic telescopic members 22, with adjacent retainers 21 maintaining equidistant or unequal axial spacing. The specific spacing is designed and determined based on the total length after expansion and the total length after contraction.

[0060] The connecting seat 23 is fixedly connected to the bottom retainer 21, and the connecting seat 23 is also fixedly connected to the main mounting ring 31, thereby connecting the feed telescopic mechanism 2 and the main mounting ring 31 into one unit.

[0061] The elastic expansion member 22 is made of aramid fiber. Aramid fiber has excellent elastic recovery performance and tensile strength. When subjected to axial compression, it can bend and deform to achieve contraction. After the pressure is released, it can rely on its own elasticity to recover to its original extended state.

[0062] The cross-sectional shape of the elastic expansion member 22 can be designed as rectangular or arc according to the stiffness requirements. In this embodiment, the cross-sectional shape of the elastic expansion member 22 adopts a flat strip structure to facilitate fixed connection with the retainer 21.

[0063] The feed 13 is fixed to one of the retainers 21 and is coaxial with the retainer 21. In this embodiment, the retainer 21 is provided with spokes, and a mounting ring 211 is provided at the center of the spokes. The feed 13 is fixed to the mounting ring 211. The sub-reflector 12 and the housing 24 are both fixed to the topmost retainer 21. The housing 24 is a cylindrical or bowl-shaped structure with an open bottom (e.g., Figure 8 and Figure 9 Its inner diameter is larger than the outer envelope diameter of the wound flexible rib 112, so that it can completely cover the wound flexible rib 112 in the contracted state.

[0064] Adjacent retainers 21 are engaged by a locating pin 27, which is vertically fixed to the retainer 21. Specifically, a locating pin 27 is vertically fixed to the upper end face of the retainer 21, and a through hole is provided at the axis of the locating pin 27. The upper end of the locating pin 27 is a stepped surface, and the lower opening of the through hole at the axis of the locating pin 27 is a stepped hole. The locating pin 27 on the lower retainer 21 is inserted into the through hole of the locating pin 27 on the upper retainer 21 (i.e., the stepped part is inserted into the stepped hole). Through this sleeve connection, the upper and lower adjacent retainers 21 remain coaxial during axial contraction and expansion, preventing radial offset or torsion. At the same time, the through hole of the locating pin 27 is also used to pass through a steel wire rope, so that the path of the steel wire rope between the retainers 21 is parallel to the antenna axis, preventing the steel wire rope from shifting laterally during contraction and expansion.

[0065] like Figures 4 to 6 As shown, the locking device includes a take-up reel 25, at least one wire rope, and an electric limiter with a telescopic head. The wire rope passes through all the retainers 21. Specifically, the wire rope passes through a through hole at the axis of the positioning pin 27, and the top end of the wire rope is fixed to the topmost retainer 21, while the bottom end is wound around the take-up reel 25.

[0066] The take-up reel 25 is rotatably connected to the bottommost retainer 21. In this embodiment, several rollers 28 are rotatably connected to the bottommost retainer 21. The outer wall of the rollers 28 is provided with grooves, and the outer wall of the take-up reel 25 is provided with ribs. The ribs are placed in the grooves, thereby realizing the rotatable connection between the take-up reel 25 and the bottommost retainer 21, while preventing the take-up reel 25 from moving axially.

[0067] An electric limiter is fixed to the bottommost retainer 21 and is used to restrain the rotation of the take-up reel 25. In this embodiment, the electric limiter is a shape memory alloy pin puller 26, and the outer circumferential surface of the take-up reel 25 is provided with a pin hole 251.

[0068] The shape memory alloy pin puller 26 is equipped with a retractable pin. In the ground retracted state, the pin of the shape memory alloy pin puller 26 is inserted into the pin hole 251 to lock the take-up reel 25 and prevent the take-up reel 25 from rotating under the vibration of the launch, thereby reliably maintaining the retracted state of the feed telescopic mechanism 2.

[0069] During the deployment phase in space, the ground control center sends an energizing signal to the shape memory alloy puller 26. The pin of the shape memory alloy puller 26 retracts from the pin hole 251, and the take-up reel 25 is unlocked. The elastic telescopic member 22 automatically extends under its own elastic restoring force, causing all the retainers 21 to move away from each other axially. Since the top of the wire rope is fixed to the topmost retainer 21 and the bottom is wound around the take-up reel 25, the wire rope is automatically released from the take-up reel 25 during the deployment process. The take-up reel 25 rotates passively and does not obstruct the deployment action.

[0070] like Figure 10 As shown, the main reflective surface 11 includes a metal reflective mesh 111 and multiple flexible ribs 112. The metal reflective mesh 111 is a mesh structure woven from metal wires and is fixed to all the flexible ribs 112 by stitching or snap-fitting. In this embodiment, stitching is used. When the flexible ribs 112 are unfolded to a preset working angle, the metal reflective mesh 111 is stretched to form a continuous umbrella-shaped reflective surface.

[0071] The flexible rib 112 is made of carbon fiber. Carbon fiber is lightweight and high-strength, and also has a certain degree of elastic deformation capability. It can be forcibly bent and wound when stored, and can provide sufficient structural rigidity to support the metal reflective mesh 111 when unfolded.

[0072] The flexible rib 112 has a pod-shaped cross-section. The pod-shaped cross-section consists of two opposing arc-shaped walls forming a cavity in the middle. This cross-sectional shape has a high moment of inertia for the same amount of material, thus providing excellent bending stiffness while ensuring lightweight.

[0073] In this embodiment, the length, curvature, and cross-sectional dimensions of each flexible rib 112 are determined based on the parabolic design parameters of the main reflector 11. The number of flexible ribs 112 is determined based on the antenna aperture and stiffness requirements, and they are evenly distributed along the circumference of the main mounting ring 31.

[0074] like Figures 11 to 15 The outer circumferential wall of the main mounting ring 31 is provided with multiple toothed grooves, each toothed groove having a bottom surface and a side surface. A mounting block 32 is hinged to the bottom surface of each toothed groove.

[0075] Specifically, each mounting block 32 is rotatably connected to the bottom surface of the toothed groove via a rotating shaft, and the root of each flexible rib 112 is fixed to a mounting block 32. In this embodiment, the mounting block 32 is provided with a mounting groove that matches the shape of the flexible rib 112. The flexible rib 112 is inserted into the mounting groove and fixed to the mounting block 32 by bolts. The side wall of the mounting groove is provided with bolt holes, through which bolts pass and through the flexible rib 112, achieving a detachable fixed connection.

[0076] All mounting blocks 32 are linked together by a synchronous transmission mechanism to achieve synchronous rotation of all mounting blocks 32. In this embodiment, the synchronous transmission mechanism includes multiple linkage gears 33, which are disposed inside the main mounting ring 31.

[0077] Each linkage gear 33 is fixedly connected to a mounting block 32 via a rotating shaft, which is rotatably connected to the main mounting ring 31. The linkage gears 33 mesh with each other in sequence. When an external force drives one of the mounting blocks 32 to rotate, the linkage gear 33 corresponding to that mounting block 32 drives the adjacent linkage gear 33 to rotate, thereby causing all mounting blocks 32 to rotate synchronously at the same angle, thus ensuring that all flexible ribs 112 are pressed down or unfolded synchronously.

[0078] like Figure 11 and Figure 16 Each mounting block 32 has a first arc groove 321. A second arc groove 322 is provided on the bottom surface of each toothed groove. When all flexible ribs 112 rotate downwards synchronously to a preset retraction angle, the first arc groove 321 and the second arc groove 322 join to form a complete circular groove. A pin 34 is inserted into the circular groove. The tight fit between the pin 34 and the circular groove restricts the rotation of the mounting block 32 relative to the toothed groove, thereby temporarily locking the mounting block 32 at the preset retraction angle. The preset retraction angle is determined according to the winding space requirements, typically 5 to 15 degrees downwards relative to the horizontal plane, preferably 10 degrees. At this angle, the axial projection height of the flexible ribs 112 is reduced, facilitating subsequent winding and retraction.

[0079] A reset spring 35 is provided between the side of each tooth groove and the corresponding mounting block 32. One end of the reset spring 35 abuts against the side of the tooth groove, and the other end abuts against the mounting block 32. When the mounting block 32 is rotated downward to a preset storage angle, the reset spring 35 is compressed and stores energy. When the pin 34 is pulled out and the flexible rib 112 is no longer constrained by the cover 24, the reset spring 35 releases its elastic potential energy, which can assist the flexible rib 112 in unfolding.

[0080] The mounting block 32 is provided with an abutment head 320. When the mounting block 32 rotates upward to a preset working angle under the drive of the reset spring 35, the abutment head 320 abuts against the side of the tooth groove, thereby limiting the maximum upward rotation angle of the mounting block 32 and stopping the flexible rib 112 at a precise preset working angle. The preset working angle is determined according to the parabolic design parameters of the main reflective surface 11.

[0081] The inner end face of the main mounting ring 31 is provided with several mounting holes, and spring pins are installed in the mounting holes. Each mounting block 32 is provided with a limiting hole that matches the spring pin. When the flexible rib 112 is extended to the preset working angle, the spring pin extends out and inserts into the limiting hole under its own spring force, thereby finally locking the mounting block 32 in the position of the preset working angle and preventing the mounting block 32 from rebounding and rotating under track vibration or thermal alternation environment.

[0082] A set screw is provided at the outer opening of the mounting hole, and the pin head of the spring pin passes through the inner opening of the mounting hole and abuts against the limiting hole. Before the storage operation on the ground, loosening the set screw allows the spring pin to have axial displacement space within the mounting hole. This is to allow the spring pin to disengage from the limiting hole, thus allowing the mounting block 32 to rotate downwards. After storage, tightening the set screw causes the spring pin to automatically pop out and insert into the limiting hole after the flexible rib 112 is fully extended, locking the block without manual operation.

[0083] After ground assembly, the main reflector 11 is first retracted. The operator presses down on the flexible ribs 112, causing all mounting blocks 32 to rotate downwards synchronously to the preset retraction angle. During rotation, due to the meshing transmission of the linkage gears 33, all flexible ribs 112 are pressed down synchronously. After being pressed into place, the first arc groove 321 and the second arc groove 322 are aligned and spliced ​​to form a circular groove. The operator inserts the pin 34 into the circular groove to temporarily lock the mounting block 32.

[0084] Subsequently, the operator rotates the main mounting ring 31, forcibly winding the flexible rib 112 around the outer circumferential wall of the main mounting ring 31. Since the flexible rib 112 is already at the preset storage angle, its axial height is reduced, and the outer envelope diameter after winding is smaller, making it easier to store.

[0085] Next, the feed telescopic mechanism 2 is retracted. The operator presses down on the connecting seat 23 or the topmost retainer 21, causing the elastic telescopic component 22 to deform under pressure. All retainers 21 move closer together, and the feed telescopic mechanism 2 retracts axially as a whole. During the retraction process, the operator manually rotates the take-up reel 25, gradually winding the previously slack wire rope onto the take-up reel 25. Since the feed telescopic mechanism 2 is compressed at this time, the wire rope tension is low, and the take-up reel 25 is easy to rotate. After winding is completed, a control signal is sent to the shape memory alloy pin puller 26 or a manual preset is directly performed, causing the pin of the shape memory alloy pin puller 26 to extend and insert into the pin hole 251 of the take-up reel 25, locking the take-up reel 25 and thus maintaining the retracted state of the feed telescopic mechanism 2.

[0086] Finally, the main mounting ring 31 is fixedly connected to the connecting seat 23, and the housing 24 is fixed to the topmost retainer 21. At this time, the housing 24 precisely covers the flexible rib 112 wrapped around the outside of the main mounting ring 31, constraining the flexible rib 112 radially and axially to prevent it from being released during transportation and launch. After it is fully retracted, the pin 34 is pulled out.

[0087] After the spacecraft enters its designated orbit, the ground control center sends an energizing signal to the shape memory alloy pin puller 26. The pin of the shape memory alloy pin puller 26 retracts from the pin hole 251, and the take-up reel 25 is unlocked. The elastic telescopic member 22 automatically extends under its own elastic restoring force, causing all the retainers 21 to move away from each other axially. During the deployment of the feed telescopic mechanism 2, the shell 24 rises synchronously with the topmost retainer 21, gradually detaching from the flexible rib 112.

[0088] After the flexible rib 112 loses the radial constraint of the housing 24, it unfolds due to its own elasticity. During the unfolding process, the mounting block 32 rotates under the action of the reset spring 35. Driven by the reset spring 35, the mounting block 32 stops rotating when the contact head 320 abuts against the side of the toothed groove, and the flexible rib 112 reaches the preset working angle. At this time, the spring pin automatically extends under the action of the spring force and inserts into the limiting hole of the mounting block 32, finally locking the mounting block 32 at the preset working angle. After the flexible rib 112 unfolds, the metal reflector 111 is expanded to form a complete umbrella-shaped reflective surface. The feed 13, the sub-reflector 12, and the main reflector 11 reach the designed working position, and the antenna is deployed in orbit.

[0089] Before ground launch, this application utilizes the active rotation of the main mounting ring 31 to wind and store the flexible rib 112. Simultaneously, the axial contraction of the feed telescopic mechanism 2 causes the shell 24 to cover and constrain the wound flexible rib 112, achieving synchronous and compact storage of the main reflector 11, feed 13, and sub-reflector 12. After entering space, the shape memory alloy puller 26 is unlocked electronically, and the elastic return of the elastic telescopic component 22 and the driving force of the reset spring 35 achieve one-time automatic deployment without manual intervention. After deployment, the flexible rib 112 is reliably locked at a preset working angle through the cooperation of the spring pin and the limiting hole, ensuring the surface accuracy of the reflector.

[0090] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements without departing from the principle of the present invention, and these improvements should also be considered within the scope of protection of the present invention.

Claims

1. A windable and retractable Cassegrain antenna, comprising a main reflector (11), a sub-reflector (12), and a feed (13), characterized in that: It also includes a feed extension mechanism (2) and a main mounting ring (31); The bottom end of the feed telescopic mechanism (2) is fixedly connected to the main mounting ring (31), and the top end is fixed with a cover (24); The feed source (13) and the sub-reflector (12) are both fixed on the feed source telescopic mechanism (2); The main reflective surface (11) includes a metal reflective mesh (111) and multiple flexible ribs (112). The metal reflective mesh (111) is fixed on all the flexible ribs (112). The root of each flexible rib (112) is hinged to the outer circumference of the main mounting ring (31). All the flexible ribs (112) can rotate synchronously downward around the hinge axis to a preset storage angle. At the preset storage angle, all flexible ribs (112) can be wrapped around the outside of the main mounting ring (31), and the shell (24) is used to cover the wrapped flexible ribs (112) to constrain their unfolding; The feed telescopic mechanism (2) is equipped with an electrically unlockable locking device for limiting the feed telescopic mechanism to remain in a retracted state. After the locking device is unlocked, the feed telescopic mechanism (2) automatically extends along the axial direction and drives the cover (24) to disengage from the flexible rib (112). After the flexible rib (112) is unrestrained, it automatically unfolds and locks to a preset working angle.

2. The windable and retractable Cassegrain antenna as described in claim 1, characterized in that: The feed telescopic mechanism (2) includes multiple coaxially arranged retainers (21), at least three elastic telescopic members (22), and a connecting seat (23). The elastic telescopic member (22) is evenly distributed around the retainer (21), and the retainer (21) is fixed at intervals on the elastic telescopic member (22). The connecting seat (23) is fixedly connected to the retainer (21) at the bottom end, and the main mounting ring (31) is fixedly connected to the connecting seat (23).

3. The windable and retractable Cassegrain antenna as described in claim 2, characterized in that: The feed source (13) is fixed on one of the holders (21) and is coaxial with the holder (21). The sub-reflective surface (12) and the housing (24) are both fixed on the topmost holder (21).

4. The windable and retractable Cassegrain antenna as described in claim 2, characterized in that: The locking device includes a take-up reel (25), at least one wire rope, and an electric limiter with a telescopic head. The wire rope passes through all the retainers (21), with the top end of the wire rope fixed to the topmost retainer (21) and the bottom end wrapped around the take-up reel (25). The take-up reel (25) is rotatably connected to the bottommost retainer (21). The electric limiter is fixed to the bottommost retainer (21), and the telescopic head of the electric limiter extends out to restrain the rotation of the take-up reel (25).

5. The windable and retractable Cassegrain antenna as described in claim 4, characterized in that: The electric limiter is a shape memory alloy pin puller (26), which has a pin hole (251) on the take-up reel (25). The retractable pin in the shape memory alloy pin puller (26) is inserted into the pin hole (251) to lock the take-up reel (25).

6. The windable and retractable Cassegrain antenna as described in claim 2, characterized in that: The two adjacent retainers (21) are connected by a positioning pin (27). The positioning pin (27) is vertically fixed on the retainer (21). The positioning pin (27) has a through hole at its axis. The positioning pin (27) on the lower retainer is inserted into the through hole of the positioning pin on the upper retainer.

7. The windable and retractable Cassegrain antenna as described in claim 2, characterized in that: The elastic expansion member (22) is made of aramid fiber.

8. The windable and retractable Cassegrain antenna as described in claim 1, characterized in that: The outer circumferential wall of the main mounting ring (31) is provided with multiple toothed grooves, each toothed groove having a bottom surface and a side surface, and a mounting block (32) is hinged to the bottom surface of each toothed groove, and the root of each flexible rib (112) is fixed on a mounting block (32).

9. The windable and retractable Cassegrain antenna as described in claim 8, characterized in that: All mounting blocks (32) are linked together by a synchronous transmission mechanism to achieve synchronous rotation of all mounting blocks (32).

10. The windable and retractable Cassegrain antenna as described in claim 9, characterized in that: The synchronous transmission mechanism includes multiple linkage gears (33), which are arranged inside the main mounting ring (31). Each linkage gear (33) is fixedly connected to a mounting block (32) via a rotating shaft, which is rotatably connected to the main mounting ring (31). All linkage gears (33) mesh with each other in sequence.

11. The windable and retractable Cassegrain antenna as described in claim 8, characterized in that: Each mounting block (32) is provided with a first arc groove (321), and each tooth groove is provided with a second arc groove (322) on its bottom surface. The first arc groove (321) and the second arc groove (322) can be spliced ​​together to form a complete circular groove. A pin (34) can be inserted into the circular groove to temporarily lock the mounting block (32) at a preset storage angle.

12. The windable and retractable Cassegrain antenna as described in claim 8, characterized in that: A reset spring (35) is provided between the side of each tooth groove and the corresponding mounting block (32). One end of the reset spring (35) abuts against the side of the tooth groove, and the other end abuts against the mounting block (32).

13. The windable and retractable Cassegrain antenna as described in claim 8, characterized in that: The mounting block (32) is provided with an abutment (320), which can abut against the side of the tooth groove to limit the maximum angle of upward rotation of the mounting block (32).

14. The windable and retractable Cassegrain antenna as described in claim 8, characterized in that: The inner end face of the main mounting ring (31) is provided with several mounting holes, and a spring pin is installed in the mounting hole. Each mounting block (32) is provided with a limiting hole that matches the spring pin. The spring pin can be inserted into the limiting hole to finally lock the mounting block (32) at the position of the preset working angle.

15. The windable and retractable Cassegrain antenna as described in claim 8, characterized in that: The mounting block (32) is provided with a mounting groove that matches the shape of the flexible rib (112). The flexible rib (112) is inserted into the mounting groove and fixed to the mounting block (32) by bolts.

16. The windable and retractable Cassegrain antenna as described in claim 1, characterized in that: The cross-section of the flexible rib (112) is pod-shaped.

17. The windable and retractable Cassegrain antenna as described in claim 1, characterized in that: The flexible rib (112) is made of carbon fiber.

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