A manual folding and unfolding device for an arm used in a space environment

Abstract

The present invention provides a manual arm folding and unfolding device for use in a space environment, comprising a ratchet input assembly, a transmission box assembly and an arm connecting assembly, wherein one side of the transmission box assembly is connected to the ratchet input assembly, and the other side of the transmission box assembly is connected to the arm connecting assembly. The present invention has the following beneficial effects: the invention adopts a gear and worm gear transmission combination mode, occupies a small space, is easy to operate, and can reliably lock the arm at any position; adopts a gear rack composite structure, realizes the function of first rotating and then translating by an astronaut's one-time input operation; and meets the astronaut's on-orbit one-handed operation and low-operation-force on-orbit operation requirements.

Description

Technical Field

[0001] The invention belongs to the field of aerospace technology, and in particular relates to a manual arm folding and unfolding device used in a space environment. Background Art

[0002] Large arm-type mechanisms, represented by space manipulators, play a vital role in aerospace technology. For example, the space station manipulator plays a very important role in lifting astronauts and transferring equipment during the assembly, construction and operation of the space station. In order to ensure the long-term on-orbit and stable operation of large arm-type mechanisms, such as manipulators, with high value and high reliability requirements, it is very important and necessary to consider their maintainability. With the rapid development of manned space flight projects, relying on the space station project, many astronaut extravehicular activities have been successfully carried out, and a series of related technologies for astronaut on-orbit maintenance have been mastered, but the related technologies have the following problems: It is impossible to reliably extend and retract large arms in the micro-low gravity environment of space, and reliably lock and stop them at any intermediate position;

[0003] It is impossible to meet the ergonomics requirements of astronauts' on-orbit operations and realize one-handed operation on-orbit.

[0004] Therefore, the present invention proposes a large-scale arm manual deployment device with high reliability that relies on astronauts' on-orbit operation, which has engineering feasibility and provides a technical solution for the subsequent maintenance of large-scale arm-type mechanisms. Summary of the invention

[0005] In view of this, the present invention aims to provide a manual arm folding and unfolding device for use in a space environment to solve at least one problem existing in the above-mentioned prior art.

[0006] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0007] A manual arm folding and unfolding device for use in a space environment comprises a ratchet input assembly, a transmission box assembly and an arm connecting assembly, wherein one side of the transmission box assembly is connected to the ratchet input assembly, and the other side of the transmission box assembly is connected to the arm connecting assembly;

[0008] The ratchet input assembly includes a handle, a reversing paddle, a No. 1 housing, a force limiting assembly and a ratchet. One side of the No. 1 housing is connected to the handle, and a reversing paddle is also arranged below the side of the No. 1 housing connected to the handle. The other side of the No. 1 housing is connected to the transmission box assembly. A ratchet is arranged inside the No. 1 housing, and a force limiting assembly is arranged above the ratchet. The axial direction of the ratchet is connected to one end of the handle.

[0009] Furthermore, the surface of the ratchet wheel is also provided with a circumferential tooth structure, and the circumferential tooth structure is used in conjunction with the force limiting component.

[0010] Furthermore, the transmission box assembly includes a cover plate, a No. 2 housing, an input bevel gear, an output bevel gear, a worm and a worm wheel. The cover plate is installed above the No. 2 housing. One side of the No. 2 housing is connected to the No. 1 housing, and the other side of the No. 2 housing is connected to the arm connecting assembly. An input bevel gear, an output bevel gear, a worm and a worm wheel are arranged inside the No. 2 housing, and the handle is coaxially connected to the input bevel gear through a ratchet. The input bevel gear and the output bevel gear are meshed for transmission. The output bevel gear is sleeved on the worm, and the worm is meshed with the worm wheel for transmission. The center axis of the worm wheel passes through the No. 2 housing and is connected to the arm connecting assembly.

[0011] Furthermore, the arm connecting assembly includes a rotating and moving assembly, a No. 1 arm connecting piece, a No. 2 arm connecting piece and a guide assembly. One side of the rotating and moving assembly is connected to the transmission box assembly, and the other side of the rotating and moving assembly is respectively connected to the No. 1 arm connecting piece and the No. 2 arm connecting piece. A guide assembly is also provided on one side of the rotating and moving assembly, and the guide assembly is connected to the No. 2 arm connecting piece.

[0012] Furthermore, the rotating and moving component includes a special-shaped cover plate and a spur gear and a gear rack composite structure inside it. The central axis of the spur gear is connected to the central axis of the worm gear, the bottom of the spur gear is meshed with the gear rack composite structure for transmission, and a guide component is arranged on one side of the gear rack composite structure.

[0013] Furthermore, the rack and pinion composite structure comprises a cylindrical gear segment and a spur gear segment of an integrally formed structure, and both the cylindrical gear segment and the spur gear segment are meshed with the spur gear for transmission.

[0014] Furthermore, the guide assembly includes a preload spring assembly, a guide shaft and two guide rods. The two guide rods are symmetrically arranged on both sides of the second arm rod connecting piece. The preload spring assembly is connected between the two guide rods. One end of the two guide rods is connected by a guide shaft.

[0015] Furthermore, the arm connecting assembly also includes a plurality of arm connecting screws, and the No. 1 arm connecting piece and the No. 2 arm connecting piece are connected to the arm to be folded via the arm connecting screws.

[0016] Compared with the prior art, the manual arm folding and unfolding device used in a space environment described in the present invention has the following advantages:

[0017] The manual folding and unfolding device for an arm used in a space environment described in the present invention adopts a combination of gears and worm gear transmission, occupies a small space, is easy to operate, and can reliably lock the arm at any position; a gear and rack composite structure is adopted to enable astronauts to perform two actions of rotation and then translation with one input operation; and the astronauts' requirements for on-orbit single-handed operation and low-operating-force on-orbit operation are met. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0019] Figure 1 It is a schematic diagram of the overall structure in the unfolded state according to an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the overall structure in a folded state according to an embodiment of the present invention;

[0021] Figure 3 It is an exploded schematic diagram of the overall structure according to an embodiment of the present invention;

[0022] Figure 4 A schematic diagram of a ratchet input assembly according to an embodiment of the present invention;

[0023] Figure 5 It is a partial schematic diagram of the ratchet input assembly according to an embodiment of the present invention;

[0024] Figure 6 A schematic diagram of a transmission box assembly according to an embodiment of the present invention;

[0025] Figure 7 This is a schematic diagram of an arm connecting assembly according to an embodiment of the present invention;

[0026] Figure 8 A partial schematic diagram of an arm connecting assembly according to an embodiment of the present invention;

[0027] Fig. 9 It is a partial second schematic diagram of the arm connecting assembly according to an embodiment of the present invention;

[0028] Fig.10 It is a schematic diagram of the connection between the overall structure and the arm rod in the unfolded state according to an embodiment of the present invention;

[0029] Fig.11 It is a schematic diagram of the connection between the overall structure and the arm rod in the folded state according to an embodiment of the present invention;

[0030] Fig.12 A schematic diagram of the on-orbit working process of the overall structure according to an embodiment of the present invention;

[0031] Fig.13 A second schematic diagram of the on-orbit working process of the overall structure according to an embodiment of the present invention;

[0032] Fig.14 The third schematic diagram of the on-orbit working process of the overall structure according to the embodiment of the present invention;

[0033] Fig.15Schematic diagram of the on-orbit operation process of the overall structure according to the embodiment of the present invention.

[0034] Description of reference numerals:

[0035] 10. Ratchet input assembly; 11. Handle; 12. Reversing paddle; 13. Housing No. 1; 14. Force limiting assembly; 15. Ratchet;

[0036] 20. Transmission box assembly; 21. Cover plate; 22. Second housing; 23. Input bevel gear; 24. Output bevel gear; 25. Worm; 26. Worm wheel;

[0037] 30. Arm connecting assembly; 31. Spur gear; 32. Gear rack composite structure; 33. Special-shaped cover plate; 34. No. 1 arm connecting piece; 35. No. 2 arm connecting piece; 36. Guide rod; 37. Preload spring assembly; 38. Guide shaft; 39. Arm connecting screw. DETAILED DESCRIPTION

[0038] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0039] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0040] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0041] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0042] like Figures 1 to 15 As shown, a manual arm folding and unfolding device used in a space environment has a mechanism scheme as shown in Figures 1 to 9 As shown, the folding and unfolding device is connected to the arm as shown in Figure 10-11 The on-orbit working process of the folding and unfolding device is shown in FIG. Figure 12 to Figure 15 The folding and unfolding device is composed of a ratchet input assembly 10, a transmission box assembly 20 and an arm connecting assembly 30.

[0043] The ratchet input assembly 10 is the power input end of the folding and unfolding device and is the on-orbit operation end of the astronauts. It is connected to the transmission box assembly 20 through the shaft hole, and transmits power to the transmission box assembly 20 to the arm connecting assembly 30 to achieve the folding and unfolding functions. The ratchet input assembly 10 mainly includes a handle 11, a reversing paddle 12, a first housing 13, a force limiting assembly 14, and a ratchet 15. The grip size of the handle 11 is designed according to the requirements related to astronaut operation, and it is connected to the ratchet 15 through an axial hole; the function of the reversing paddle 12 is to change the ratchet-ratchet meshing direction inside the ratchet input assembly 10, so as to achieve the folding operation or unfolding operation of the movement direction of the folding and unfolding device; the ratchet input assembly 10 has the same function as the ratchet input assembly 10 in a conventional ratchet wrench, the difference being that a circumferential tooth structure is designed on the ratchet 15 in the ratchet input assembly 10, which is used in conjunction with the force limiting assembly 14, so that when the astronaut reciprocates the handle 11, the previous operation will not be brought back, thereby ensuring the astronaut's one-handed operation; the No. 1 housing 13 provides installation support for various parts of the ratchet input assembly 10, and is connected to the transmission box assembly 20.

[0044] The transmission box assembly 20 is a reduction box, which is used to transmit power and ensure that the folding action is reliably locked at any position. One end of the transmission box assembly 20 is connected to the ratchet input assembly 10, and the other end is connected to the arm connecting assembly 30. The transmission box assembly 20 mainly includes a cover plate 21, a second housing 22, an input bevel gear 23, an output bevel gear 24, a worm 25, and a worm wheel 26; wherein the input gear 23 is connected to the output shaft of the ratchet input assembly 10, and is the power input of the transmission box assembly; the input bevel gear 23 and the output bevel gear 24 are a pair of reduction bevel gears, and the output bevel gear 24 and the worm 25 share a transmission shaft, that is, the output bevel gear 24 drives the worm 25 to rotate, and the worm 25 drives the worm wheel 26 to rotate; the worm wheel 26 is the output of the transmission box assembly 20, which is connected to the arm connecting assembly 30 to transmit the input power to the arm connecting assembly 30. The second housing 22 provides installation support for various parts of the transmission box assembly 20 and related shaft systems. The cover plate 21 is an auxiliary structure and together with the second housing 22 constitutes the box body of the transmission box assembly 20.

[0045] The arm connecting assembly 30 is the power output part of the folding and unfolding device, which is directly connected to the arm to be unfolded. The arm connecting assembly 30 mainly includes a spur gear 31, a gear rack composite structure 32, a special-shaped cover plate 33, a first arm connecting piece 34, a second arm connecting piece 35, a guide rod 36, a preload spring assembly 37, a guide shaft 38 and an arm connecting screw 39. The spur gear 31 is connected to the transmission box assembly 20, receives the power transmitted by the astronaut, and is installed on the first arm connecting piece 34; the gear rack composite structure 32 is designed as a structure combining cylindrical gears and spur gears, and the positions and sizes of the cylindrical gear segments and the spur gear segments are designed and selected according to the arm unfolding and folding angles; the gear rack composite structure 32 is meshed with the spur gear 31 and connected to the second arm connecting piece 35. The rotation and movement of the gear rack composite structure drives the second arm connecting piece 35 to rotate and move; the guide rod 36 is connected to the second arm connecting piece 35 and moves with it to play a guiding role; the guide rods 36 on both sides are connected by guide shafts 38; the preload spring assembly 37 is connected to the guide rod 36, and its function is to provide the guide rod with a preload force in the direction of the spring axis to offset the possible movement caused by the rotation of the gear rack composite structure 32. The special-shaped cover plate 33 provides protection for the spur gear 31, the gear rack composite structure 32 and other structures, and provides an interface with the transmission box assembly 20. The first arm connecting piece 34 and the second arm connecting piece 35 are directly connected to the arm to be folded via the arm connecting screws 39 .

[0046] The invention belongs to the field of aerospace technology, is applied to an arm that needs to be folded and extended in a space environment, and is used by astronauts to manually operate the folding and extension of the space arm to achieve the folding and storage of the foldable arm and subsequent work after the extension.

[0047] Purpose of the present invention:

[0048] The space station manipulator is a key equipment for the construction, operation and maintenance of the space station, and the arm is a key component of the manipulator. In order to meet the needs of the subsequent development of the space station, the present invention proposes a manually operated arm folding and unfolding device, which can realize the on-orbit unfolding and folding of large and ultra-long arms through on-orbit operation by astronauts, providing necessary conditions for subsequent operations. The device can be operated by astronauts with one hand, and at the same time, the relative rotation and translation functions of the two arms can be realized, and the folding and unfolding arm can be maintained at any position during the folding and unfolding process, which improves the safety and reliability of astronauts' on-orbit operations.

[0049] Mainly solve the following technical problems:

[0050] It can realize the reliable extension and retraction of large arms in the micro-low gravity environment of space, and reliably lock and stop at any intermediate position; it can meet the ergonomics of astronauts' on-orbit operations and realize one-handed operation on-orbit.

[0051] Advantages of the present invention:

[0052] The combination of gear and worm gear transmission takes up little space, is easy to operate, and can reliably lock the arm at any position.

[0053] The composite structure of gears and racks is adopted to enable the astronauts to achieve the functions of first rotating and then translating with one input operation;

[0054] It meets the astronauts' needs for on-orbit one-handed operation and low-force operation.

[0055] Example 1

[0056] like Figures 1 to 9 The structure of each part shown, combined with Figure 10-11 The connection method between the folding device and the arm, Figure 12 to Figure 15 The working process of the folding and unfolding device is schematically shown, and a specific embodiment of the device is briefly described as follows:

[0057] The folding and unfolding device comprises three parts: a ratchet input assembly 10, a transmission box assembly 20, and an arm connecting assembly 30. The connection sequence from the astronaut input end to the output arm end is ratchet input assembly 10-transmission box assembly 20-arm connecting assembly 30. The ratchet input assembly is connected to the input bevel gear 23 of the transmission box assembly 20 through an axial hole via a ratchet 15. When the astronaut shakes the handle 11, the ratchet input assembly 10 can transmit power to the input bevel gear 23, thereby driving the output bevel gear 24-worm 25-worm wheel 26 in the gear box transmission system to rotate in sequence; the worm wheel 26 shaft in the transmission box assembly 20 is connected to the spur gear 31 of the arm connecting assembly 30 through an axial hole, and the shaft system of the spur gear 31 is installed on the No. 1 arm connecting assembly. The first arm connecting member 34 is equivalent to a "fixed frame"; the gear rack composite structure 32 is meshed with the spur gear 31, and the gear rack composite structure 32 and its shaft system are connected to the second arm connecting member 35, driving the second arm connecting member 35 to rotate and move; the guide rods 36 are respectively arranged on both sides of the second arm connecting member 35, and the guide rods 36 on both sides are connected by the guide shaft 38 to achieve synchronous movement, and the guide shaft 38 is installed in the hole of the second arm connecting member 35; the preload spring assembly 37 is connected to the guide rod 36 through the spring guide rod, and the spring preload force of the spring preload assembly 37 acts on the guide rod 36 to offset the translation force generated during the meshing process of the spur gear 31 and the gear rack composite structure 32. The special-shaped cover plate 33 is connected to the second housing 22 of the transmission box assembly 20, and at the same time provides a protective cover for the spur gear 31, the gear rack composite structure 32, etc. of the arm connecting assembly 30. The first arm connecting piece 34 and the second arm connecting piece 35 are designed with arc structures to adapt to the arm assembly to be deployed, and the two connecting pieces are connected by arm connecting screws 39.

[0058] Specifically, Figure 7 to Figure 9 As shown, the spur gear 31 and its shaft system are connected to the frame fixedly connected to the No. 1 arm connecting member 34, and the spur gear 31 can rotate relative to the No. 1 arm connecting member 34 and mesh with the gear rack compound structure 32; the gear rack compound structure 32 and its shaft system are installed on one side of the guide rod 36, and the gear rack compound structure 32 can rotate relative to the guide rod 36; at the same time, the gear rack compound structure 32 and its shaft system are connected to the No. 2 arm connecting member 35 by a key-keyway method, that is, the No. 2 arm connecting member 35 and the gear rack compound structure 32 and the No. 2 arm connecting member 35 can be fixedly connected, and the No. 2 arm connecting member 35 rotates and moves together with the gear rack compound structure 32; under the action of the preload spring assembly 37, the guide rod 36 is maintained at Figure 7 to Figure 9 guide rod 36 under the action of the guide shaft 38, when a certain external force is applied, can move along the axial direction of the guide rod 37.

[0059] Working process of the arm connecting assembly 30:

[0060] When the spur gear 31 is meshed with the gear segment of the rack and pinion composite structure 32, since the rack and pinion composite structure 32 can only rotate relative to the guide rod 36, the rack and pinion composite structure 32 is fixedly connected to the No. 2 arm rod connecting piece 35. Under the action of the preload spring assembly 37, the No. 2 arm rod connecting piece 35 rotates with the rotation of the rack and pinion composite structure 32 and does not move. When the spur gear 31 is meshed with the rack segment of the rack and pinion composite structure 32, on the one hand, since the rotation stroke of the No. 2 arm rod connecting piece 35 is limited by the corresponding limiting structure of the No. 1 arm rod connecting piece 34, it cannot continue to rotate. On the other hand, the meshing of the spur gear 31 with the rack segment of the rack and pinion composite structure 32 applies a force along the rack direction to the rack and pinion composite structure 32, which offsets the spring force of the preload spring assembly 37, prompting the rack and pinion composite structure 32 to drive the No. 2 arm rod connecting piece 35 to move along the axial direction of the guide rod 36.

[0061] The operation and working process of the folding and unfolding device described in the present invention will be described below based on the diagrams and in combination with the above embodiments:

[0062] Figure 10-11 The figure shows that after the folding and unfolding device is connected to the arm, the entire assembly is in the final two states of folding and unfolding. Figure 12 to Figure 15 As shown, combined Figures 1 to 9 The structure of the folding and unfolding device is composed of the arm assembly with the folding and unfolding device in the folded state ( Fig.12 ), needs to be expanded to the docking state ( Fig.15); The astronaut swings the handle 11 in the manner shown by arrow 1. Due to the existence of the ratchet input assembly 10, the astronaut's swing can be converted into a full-circle motion of the input bevel gear 23 of the transmission box assembly 20, thereby driving the arm b to rotate relative to the arm a in the direction shown by arrow 2 in the figure. By continuously operating the handle 11, the arm a and the arm b experience the following Figure 13 to Figure 14 At the position shown, there is a gap d between arm a and arm b, and the cylindrical gear segment of the gear rack composite structure 32 in the arm connection assembly 30 is meshed, and the second arm connection piece moves to the limit position of the first arm connection piece; the astronaut continues to operate the handle 11, and the spur gear 31 in the arm connection assembly 30 meshes with the spur gear segment of the gear rack composite structure 32, thereby driving arm b to make a linear motion relative to arm a in the direction shown by arrow 3 in the figure until the docking is completed. In short, the astronaut operates the folding and unfolding device to complete the composite motion of arm b first rotating and then translating relative to arm a.

[0063] The operation process described above assumes that arm a and arm b are in a folded state and need to be operated to an unfolded state; if it is necessary to operate from the unfolded state to the folded state, the astronaut operates the reversing paddle 12 to change the movement output direction of the folding device, and then operates the handle 11. The operation method is the same as the above process, and the movement process is opposite to the above process.

[0064] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A manual folding and unfolding device for an arm used in a space environment, characterized in that: It comprises a ratchet input assembly (10), a transmission box assembly (20) and an arm connecting assembly (30), wherein one side of the transmission box assembly (20) is connected to the ratchet input assembly (10), and the other side of the transmission box assembly (20) is connected to the arm connecting assembly (30); The ratchet input assembly (10) comprises a handle (11), a reversing paddle (12), a first housing (13), a force limiting assembly (14) and a ratchet (15); one side of the first housing (13) is connected to the handle (11); a reversing paddle (12) is further arranged below the side of the first housing (13) connected to the handle (11); the other side of the first housing (13) is connected to a transmission box assembly (20); a ratchet (15) is arranged inside the first housing (13); a force limiting assembly (14) is arranged above the ratchet (15); and the axial direction of the ratchet (15) is connected to one end of the handle (11); The transmission box assembly (20) comprises a cover plate (21), a second housing (22), an input bevel gear (23), an output bevel gear (24), a worm (25) and a worm wheel (26); the cover plate (21) is installed above the second housing (22); one side of the second housing (22) is connected to the first housing; the other side of the second housing (22) is connected to the arm connecting assembly (30); the input bevel gear (23), the output bevel gear (24), the worm (25) and the worm wheel (26) are arranged inside the second housing (22); the handle is coaxially connected to the input bevel gear (23) through a ratchet; the input bevel gear (23) and the output bevel gear (24) are meshed for transmission; the output bevel gear (24) is sleeved on the worm (25); the worm (25) and the worm wheel (26) are meshed for transmission; the central axis of the worm wheel (26) passes through the second housing (22) and is connected to the arm connecting assembly (30); The arm connecting assembly (30) comprises a rotating and moving assembly, a first arm connecting piece (34), a second arm connecting piece (35) and a guide assembly. One side of the rotating and moving assembly is connected to the transmission box assembly (20), and the other side of the rotating and moving assembly is respectively connected to the first arm connecting piece (34) and the second arm connecting piece (35). A guide assembly is also provided on one side of the rotating and moving assembly, and the guide assembly is connected to the second arm connecting piece (35).

2. The arm manual folding and unfolding device for use in a space environment according to claim 1, characterized in that: The surface of the ratchet wheel (15) is also provided with a circumferential tooth structure, and the circumferential tooth structure is used in conjunction with the force limiting component (14).

3. The arm manual folding and unfolding device for use in a space environment according to claim 1, characterized in that: The rotating and moving assembly comprises a special-shaped cover plate (33) and a spur gear (31) and a gear rack composite structure (32) therein; the central axis of the spur gear (31) is connected to the central axis of the worm gear (26); the bottom of the spur gear (31) is meshed with the gear rack composite structure (32) for transmission; and a guide assembly is arranged on one side of the gear rack composite structure (32).

4. The arm manual folding and unfolding device for use in a space environment according to claim 3, characterized in that: The gear rack composite structure (32) comprises a cylindrical gear segment and a spur gear segment of an integrally formed structure, and both the cylindrical gear segment and the spur gear segment are meshed with the spur gear (31) for transmission.

5. The arm manual folding and unfolding device for use in a space environment according to claim 1, characterized in that: The guide assembly comprises a preload spring assembly (37), a guide shaft (38) and two guide rods (36), wherein the two guide rods (36) are symmetrically arranged on both sides of the second arm connecting member (35), the preload spring assembly (37) is connected between the two guide rods (36), and one end of the two guide rods (36) is connected via the guide shaft (38).

6. The arm manual folding and unfolding device for use in a space environment according to claim 1, characterized in that: The arm connecting assembly (30) further comprises a plurality of arm connecting screws (39), and the first arm connecting piece (34) and the second arm connecting piece (35) are connected to the arm to be folded via the arm connecting screws (39).

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