On-orbit butt-joint filling structure for medium and small spacecrafts

Abstract

The invention discloses an on-orbit butt joint filling structure for medium and small spacecrafts, and belongs to the technical field of on-orbit service of spacecrafts, the on-orbit butt joint filling structure comprises a supplied end connector and a supply end connector, the supply end connector is assembled in a floating connector mechanism, and the bottom of the floating connector mechanism is in transmission connection with a driving mechanism; a synchronous linkage locking assembly is assembled between the floating connector mechanism and the driving mechanism, and a base is fixedly assembled at the bottom of the driving mechanism. A set of power is utilized to drive the holding claws to act to capture and hold the supplied joints and complete two core actions of butt joint of the supplied joints and the supplied joints, and the layout of a plurality of motors in a traditional scheme is replaced. The highly integrated design concept is combined with a compact mechanical structure, so that the device becomes one of light and compact butt-joint filling solutions meeting the in-orbit butt-joint filling requirements of small and medium-sized spacecrafts, and the strict limitation of the small and medium-sized spacecrafts on the envelope and the weight of the butt-joint filling mechanism is met.

Description

Technical Field

[0001] This invention relates to the field of on-orbit servicing technology for spacecraft, and more specifically to an on-orbit docking and refueling structure for small and medium-sized spacecraft. Background Technology

[0002] With the rapid development of aerospace technology, the technology for in-orbit docking and refueling of large spacecraft such as spacecraft and space stations has become relatively mature. However, the demand for in-orbit docking and refueling of small and medium-sized spacecraft is gradually increasing.

[0003] Existing docking technologies applicable to or intended for use on small and medium-sized spacecraft mainly face the following types of technical bottlenecks: Mechanical docking mechanisms: These typically employ passive components such as springs, jaws, and threaded joints for buffering and locking. While these solutions are simple in structure and highly reliable, they often suffer from issues such as high docking impact and the inability to actively and controllably separate (and are often not reusable).

[0004] Electromagnetic docking mechanism: This mechanism achieves non-contact adsorption and separation by controlling the on / off state of an electromagnet. Its advantage lies in the gentle docking process without physical impact. However, its locking force and rigidity are relatively limited, and continuous power is required to maintain the locking state, resulting in huge energy consumption. Most importantly, simple electromagnetic adsorption is difficult to achieve a rigid, sealed mechanical connection.

[0005] All-electric drive docking mechanism: This type of mechanism uses multiple motors or servos to perform different functions such as capture, approach, and locking. Its advantages are high control precision and powerful functionality. However, the multi-driver approach inevitably leads to high system complexity, large weight, high cost, and reduced reliability (increased single points of failure), which also runs counter to the goals of miniaturization, high integration, and high reliability pursued by micro and nano satellites. Summary of the Invention

[0006] The purpose of this invention is to provide an on-orbit docking and refueling structure for small and medium-sized spacecraft to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: an on-orbit docking and refueling structure for small and medium-sized spacecraft, comprising a refueling end connector and a refueling end connector, wherein the refueling end connector is assembled in a floating connector mechanism, the bottom of the floating connector mechanism is connected to a drive mechanism, a synchronous linkage locking assembly is assembled between the floating connector mechanism and the drive mechanism, and a base is fixedly assembled at the bottom of the drive mechanism.

[0008] Preferably, the floating joint mechanism includes an assembly base, a hollow fixed shaft integrally formed in the middle of the assembly base, an assembly body fixedly connected to the top of the fixed shaft, a floating head assembled in the assembly body, a tension spring assembled between the floating head and the assembly body, and a supply end joint fixedly connected to the top of the floating head.

[0009] Preferably, the number of tension springs is at least eight, and the eight tension springs are arranged in two layers, with four tension springs in each layer. The four tension springs are distributed at 90° intervals around the center of the assembly.

[0010] Preferably, the driving mechanism includes a drive motor, which is fixedly mounted in the middle of the base. A lead screw is fixedly connected to the output end of the drive motor, and a lead screw nut is screwed onto the outer side wall of the lead screw. The lead screw and the lead screw nut form a pair of T-shaped transmission thread pairs, and the lead screw nut is fixedly mounted at the bottom center of the fixed shaft.

[0011] Preferably, a motor bracket is fixedly mounted on the top of the base, and a micro switch bracket is fixedly connected to the top of the motor bracket. An upper micro switch and a lower micro switch are fixedly mounted inside the micro switch bracket.

[0012] Preferably, the synchronous linkage locking assembly includes a gripper, one end of which is rotatably connected to the side wall of the motor bracket, and the other end of which passes through an assembly slot. The assembly slot is formed in the assembly base, and a bearing is assembled in the assembly slot.

[0013] Preferably, the number of the gripper and the assembly slot is at least three, and the three grippers and the assembly slot are evenly distributed in a circle with a 120° interval around the center of the assembly seat.

[0014] Preferably, the bearings in each assembly slot are divided into two groups, with two bearings in each group. One group of bearings is located on the upper side of the assembly slot near the axis of the assembly seat, and its outer ring is slidably connected to the inner wall of the gripper. The other group of bearings is located on the lower side of the assembly slot away from the axis of the assembly seat, and its outer ring is slidably connected to the outer wall of the gripper.

[0015] Preferably, the bottom center of the supply end connector is integrally formed with a sealing cylindrical part and a guide cone part, and the side wall of the supply end connector is uniformly provided with a passive end locking part.

[0016] Compared with existing technologies, the advantages of this invention are: an on-orbit docking and refueling structure for small and medium-sized spacecraft utilizes a single power-driven gripper to capture and hold the refueling connector, completing the two core actions of docking the refueling connector and the refueled connector, replacing the traditional scheme with a multi-motor layout. This highly integrated design concept, combined with a compact mechanical structure, makes it one of the most lightweight and compact docking and refueling solutions for the on-orbit docking and refueling needs of small and medium-sized spacecraft, meeting the stringent limitations of small and medium-sized spacecraft on the envelope and weight of the docking and refueling mechanism.

[0017] This invention utilizes the reverse self-locking characteristics of mechanical structures such as a gripper to capture the supplied connector and maintain the locking force after docking, including the lead screw. The motor can be completely de-energized, achieving zero power consumption during the locking state. Compared to purely electromagnetic solutions requiring continuous power or solutions requiring multiple motors to be on standby, this significantly reduces energy demand.

[0018] The entire retraction, clamping, and separation process of this invention is completed by a single motor rotating in both directions—a reversible process. The mechanism can withstand several "docking-clamping-separation" cycles, meeting the routine needs of on-orbit maintenance, upgrades, and resupply for small and medium-sized spacecraft, and greatly reducing the cost of on-orbit docking and refueling for such spacecraft. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the present invention when the supply end connector and the supply end connector are not connected.

[0020] Figure 2 This is a schematic diagram of the structure when the supply end connector and the supply end connector of the present invention are connected.

[0021] Figure 3 This is a front sectional view of the supply end connector and the supply end connector of the present invention when they are connected.

[0022] Figure 4 This is a schematic diagram of the floating joint mechanism of the present invention.

[0023] Figure 5 This is a front sectional view of the floating joint mechanism of the present invention.

[0024] Figure 6 This is a schematic diagram of the structure of the present invention before the housing is assembled and connected.

[0025] Figure 7 This is a schematic diagram of the assembly and docking structure of the present invention after the housing is assembled.

[0026] In the diagram: 1. Supply end connector; 1-1. Sealed cylindrical part; 1-2. Guide cone part; 1-3. Passive end locking part; 2. Supply end connector; 3. Floating connector mechanism; 3-1. Assembly base; 3-2. Fixed shaft; 3-3. Assembly body; 3-4. Floating head; 3-5. Tension spring; 4. Drive mechanism; 4-1. Drive motor; 4-2. Lead screw; 4-3. Lead screw nut; 4-4. Motor bracket; 5. Synchronous linkage locking assembly; 5-1. Claw; 5-2. Assembly groove; 5-3. Bearing; 6. Base; 7. Microswitch bracket; 8. Upper microswitch; 9. Lower microswitch; 10. Propellant supply pipeline; 11. Pipeline bracket; 12. Housing. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0028] Please see Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 The present invention provides a technical solution: an on-orbit docking and refueling structure for small and medium-sized spacecraft, including a refueling end connector 1 and a refueling end connector 2. After the refueling end connector 2 is inserted into the refueling end connector 1 to complete the docking of the two connectors, fuel can be refueled into the refueling end connector 1.

[0029] The supply end connector 2 is assembled within the floating connector mechanism 3. By controlling the movement of the floating connector mechanism 3, the connection between the supply end connector 2 and the supply end connector 1 is achieved. Figure 4 and Figure 5 As shown, the floating joint mechanism 3 includes an assembly base 3-1, a fixed shaft 3-2 integrally formed in the middle of the assembly base 3-1, an assembly body 3-3 integrally formed on the top of the fixed shaft 3-2, a floating head 3-4 assembled inside the assembly body 3-3, and a tension spring 3-5 fixedly assembled between the floating head 3-4 and the inner wall of the assembly body 3-3. The supply end connector 2 is detachably and fixedly connected to the top of the floating head 3-4 through a threaded shell. The number of tension springs 3-5 is at least eight. The eight tension springs 3-5 are arranged in two layers, upper and lower, with four tension springs 3-5 in each layer. The four tension springs 3-5 are distributed in a circle at 90° intervals around the center of the assembly 3-3. The tension of the eight tension springs 3-5 keeps the supply end connector 2, which is fixedly connected to the floating head 3-4, in a suspended state within the assembly 3-3, giving it a multi-degree-of-freedom positional movement capability.

[0030] One end of the propellant supply pipeline 10 is fixedly connected to the side wall of the refueling end connector 2. The other end of the propellant supply pipeline 10 is connected to an external propellant supply device. The surface of the mounting base 3-1 is detachably and fixedly connected to a pipeline support 11 by threads. The pipeline support 11 supports and limits the propellant supply pipeline 10.

[0031] The bottom of the floating connector mechanism 3 is equipped with a drive mechanism 4. The drive mechanism 4 can drive the floating connector mechanism 3 to move up and down, thereby connecting the supply end connector 2 with the supply end connector 1. Figure 3 As shown, the drive mechanism 4 includes a drive motor 4-1, which is fixedly mounted on the top of the base 6. A lead screw 4-2 is fixedly connected to the output end of the drive motor 4-1. The drive motor 4-1 is a stepper motor, electrically connected to an external power supply and an external controller. The external controller controls the forward and reverse rotation of the output end of the drive motor 4-1. A lead screw nut 4-3 is screwed onto the outer wall of the lead screw 4-2. The lead screw 4-2 and the lead screw nut 4-3 form a pair of T-shaped transmission thread pairs. The lead screw nut 4-3 is fixedly mounted on the bottom of the fixed shaft 3-2. The fixed shaft 3-2 is hollow. By driving the lead screw 4-2 to rotate through the drive motor 4-1, the lead screw nut 4-3 can drive the mounting base 3-1 to move up and down along the lead screw 4-2.

[0032] The floating joint mechanism 3 has a certain correction capability, which can adapt to the slight deviations that exist during the initial docking, reducing the stringent requirements for the positioning accuracy of the spacecraft's end during the docking process.

[0033] like Figure 3 As shown, a motor bracket 4-4 is detachably and fixedly mounted on the surface of the base 6 by fixing bolts. The drive motor 4-1 is mounted inside the motor bracket 4-4, which protects the drive motor 4-1. A micro switch bracket 7 is fixedly mounted on the top of the motor bracket 4-4. An upper micro switch 8 and a lower micro switch 9 are fixedly mounted on the upper and lower ends of the micro switch bracket 7, respectively. The upper micro switch 8 and the lower micro switch 9 are respectively connected to the external controller for electrical signal to determine the docking status of the supply end connector 2 and the supply end connector 1. When the floating connector mechanism 3 moves downward to trigger the lower micro switch 9, a signal is generated that the supply end connector 2 and the supply end connector 1 have separated. When the floating connector mechanism 3 moves upward to trigger the upper micro switch 8, a signal is generated that the supply end connector 2 and the supply end connector 1 have docked.

[0034] The lead screw nut 4-3 and lead screw 4-2 have a self-locking design, which, together with the stepper motor drive motor 4-1, enables the structure to maintain the locking force even when the power is off, achieving zero power consumption.

[0035] like Figure 2 and Figure 3 As shown, a synchronous linkage locking assembly 5 is assembled between the motor bracket 4-4 and the mounting base 3-1. The synchronous linkage locking assembly 5 is used to lock the supply end connector 2 and the supplied end connector 1. The synchronous linkage locking assembly 5 includes a gripper 5-1. One end of the gripper 5-1 is rotatably connected to the side wall of the motor bracket 4-4 via a pin. The other end of the gripper 5-1 passes through the mounting groove 5-2, which is opened in the mounting base 3-1. A bearing 5-3 is fixedly assembled in the mounting groove 5-2. There are at least three grippers 5-1 and three mounting grooves 5-2. The three grippers 5-1 and the three mounting grooves 5-2 are evenly distributed circumferentially at 120° intervals around the center of the mounting base 3-1. The bearings 5-3 in the assembly slot 5-2 are divided into two groups, with two bearings 5-3 in each group. One group of bearings 5-3 is located on the upper side of the assembly slot 5-2 near the axis of the assembly seat 3-1, and its outer ring is slidably connected to the inner wall of the claw 5-1. The other group of bearings 5-3 is located on the lower side of the assembly slot 5-2 away from the axis of the assembly seat 3-1, and its outer ring is slidably connected to the outer wall of the claw 5-1. When the assembly seat 3-1 moves up and down through the drive mechanism 4, the bearings 5-3 will move up and down with the assembly seat 3-1, thereby pushing the claws 5-1 in contact with the bearings 5-3 to retract inward or unfold outward, realizing the locking and unlocking action.

[0036] like Figure 3 As shown, a sealing cylindrical part 1-1 and a guide cone part 1-2 are integrally formed at the bottom center of the supply end connector 1. The sealing cylindrical part 1-1 is used to connect with the top cylinder of the supply end connector 2. The guide cone part 1-2 is used to cooperate with the insertion of the supply end connector 2 and to cooperate with the cone surface of the supply end connector 2. A passive end locking part 1-3 is integrally formed on the side wall of the supply end connector 1. The passive end locking part 1-3 is groove-shaped, and its number corresponds to the number of grippers 5-1. It is used to cooperate with the grippers 5-1 to lock the supply end connector 1 and the supply end connector 2.

[0037] like Figure 6 As shown, a housing 12 is fixedly connected to the top of the base 6. The housing 12 protects the drive mechanism 4 and the floating joint mechanism 3. An electrical connector is embedded and fixedly assembled in the side wall of the housing 12. The input end of the electrical connector is electrically connected to an external power source, and the output end of the electrical connector is electrically connected to the input end of the drive motor 4-1. The drive motor 4-1 is powered through the electrical connector.

[0038] The docking process is as follows: At the initial stage of docking, the drive motor 4-1 drives the lead screw 4-2 to rotate, and the lead screw nut 4-3 converts the rotational motion into the linear motion of the floating joint mechanism 3. The floating joint mechanism 3 completes its upward movement by separating the supply end joint 2 from the supply end joint 1. At the same time as the mounting base 3-1 moves upward, it drives the bearing 5-3 to move upward synchronously. The upward-moving bearing 5-3 pushes the gripper 5-1 to retract inward. When the bearing 5-3 moves to the straight section of the gripper 5-1, the top of the gripper 5-1 inserts into the passive end locking part 1-3 to lock the supply end joint 1. At the same time, the gripper 5-1 generates a slight interference fit. A reliable clamping torque is formed. As the floating joint mechanism 3 continues to move upward, the supply end joint 2 is inserted into the guide cone 1-2 of the supply end joint 1. During the insertion of the supply end joint 2, the floating joint 3-4 can float freely within the assembly 3-3. The cooperation with the guide cone 1-2 corrects the insertion position of the supply end joint 2. The continued upward movement of the floating joint 3-4 can control the supply end joint 2 to be fully inserted into the supply end joint 1, completing the docking of the two joints. Then, the sealing ring set by the outer wall of the supply end joint 2 and the inner wall of the supply end joint 1 forms a double seal at the joint position, improving the sealing performance of the connection.

Claims

1. An on-orbit docking and refueling structure for small and medium-sized spacecraft, characterized in that, It includes a supply end connector (1) and a supply end connector (2). The supply end connector (2) is assembled in a floating connector mechanism (3). The bottom of the floating connector mechanism (3) is connected to a drive mechanism (4). A synchronous linkage locking assembly (5) is assembled between the floating connector mechanism (3) and the drive mechanism (4). The bottom of the drive mechanism (4) is fixedly equipped with a base (6).

2. The on-orbit docking and refueling structure for small and medium-sized spacecraft according to claim 1, characterized in that: The floating joint mechanism (3) includes an assembly base (3-1), a hollow fixed shaft (3-2) is integrally formed in the middle of the assembly base (3-1), an assembly body (3-3) is fixedly connected to the top of the fixed shaft (3-2), a floating head (3-4) is assembled inside the assembly body (3-3), a tension spring (3-5) is assembled between the floating head (3-4) and the assembly body (3-3), and the supply end joint (2) is fixedly connected to the top of the floating head (3-4).

3. The on-orbit docking and refueling structure for small and medium-sized spacecraft according to claim 2, characterized in that: The number of tension springs (3-5) is at least eight, and the eight tension springs (3-5) are arranged in two layers, upper and lower, with four tension springs (3-5) in each layer. The four tension springs (3-5) are distributed at 90° intervals around the center of the assembly (3-3).

4. The on-orbit docking and refueling structure for small and medium-sized spacecraft according to claim 1, characterized in that: The drive mechanism (4) includes a drive motor (4-1), which is fixedly mounted in the middle of the base (6). The output end of the drive motor (4-1) is fixedly connected to a lead screw (4-2). A lead screw nut (4-3) is screwed onto the outer wall of the lead screw (4-2). The lead screw (4-2) and the lead screw nut (4-3) form a pair of T-shaped transmission thread pairs. The lead screw nut (4-3) is fixedly mounted at the bottom center of the fixed shaft (3-2).

5. The on-orbit docking and refueling structure for small and medium-sized spacecraft according to claim 4, characterized in that: The base (6) is fixedly fitted with a motor bracket (4-4), and the top of the motor bracket (4-4) is fixedly connected with a micro switch bracket (7). The micro switch bracket (7) is fixedly fitted with an upper micro switch (8) and a lower micro switch (9).

6. The on-orbit docking and refueling structure for small and medium-sized spacecraft according to claim 1, characterized in that: The synchronous linkage locking assembly (5) includes a gripper (5-1), one end of which is rotatably connected to the side wall of the motor bracket (4-4), and the other end of which passes through the assembly groove (5-2). The assembly groove (5-2) is opened in the assembly base (3-1), and a bearing (5-3) is assembled in the assembly groove (5-2).

7. The on-orbit docking and refueling structure for small and medium-sized spacecraft according to claim 6, characterized in that: The number of each of the gripper (5-1) and the assembly slot (5-2) is at least three, and the three grippers (5-1) and the assembly slots (5-2) are evenly distributed around the center of the assembly base (3-1) in a circle with a circumference of 120° intervals.

8. The on-orbit docking and refueling structure for small and medium-sized spacecraft according to claim 6, characterized in that: The bearings (5-3) in each of the assembly slots (5-2) are divided into two groups, with two bearings (5-3) in each group. One group of bearings (5-3) is located on the upper side of the assembly slot (5-2) near the axis of the assembly seat (3-1), and its outer ring is slidably connected to the inner wall of the claw (5-1). The other group of bearings (5-3) is located on the lower side of the assembly slot (5-2) away from the axis of the assembly seat (3-1), and its outer ring is slidably connected to the outer wall of the claw (5-1).

9. The on-orbit docking and refueling structure for small and medium-sized spacecraft according to claim 1, characterized in that: The bottom center of the supply end connector (1) is integrally formed with a sealing cylindrical part (1-1) and a guide cone part (1-2), and the side wall of the supply end connector (1) is evenly provided with a passive end locking part (1-3).

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