A lightweight quasi-statically fixed focusing mechanism and method for a space camera

Abstract

This invention provides a lightweight quasi-statically determinate focusing mechanism and method for a space camera, including a focusing base, a main support, a sliding base, a drive mechanism, and a transmission mechanism. The focusing base and the sliding base are located on both sides of the main support and are respectively installed on the main load-bearing structure of the space camera. The focusing base and the main support form a cylindrical guide pair, and the sliding base and the main support form a planar guide pair. The main support carries the reflector assembly and provides an installation interface for the reflector assembly. The drive mechanism and the transmission mechanism are installed on it. The drive mechanism drives the transmission mechanism to rotate, causing the main support to displace relative to the focusing base and the sliding base, thereby achieving focusing. This novel focusing mechanism uses a combination of cylindrical and planar guide pairs to achieve single-degree-of-freedom statically determinate constraints. The mechanism has a simple composition, is easy to manufacture and assemble, can support large-sized reflector assemblies, and achieves a lightweight design.

Description

Technical Field

[0001] This invention belongs to the field of space optical remote sensing technology, and specifically relates to a lightweight quasi-statically fixed focusing mechanism and method for a space camera. Background Technology

[0002] High-resolution space cameras require high stability in the position and angle of their optical components. Affected by multiple factors such as launch phase vibration, temperature and humidity changes, weightlessness, and internal stress release, the optical system may defocus after the camera enters orbit, reducing image quality. Therefore, space cameras typically employ focusing mechanisms to compensate for this defocusing effect. Mirror focusing is a common method. This type of focusing mechanism carries spatially sensitive optical components and has high requirements for attitude stability, motion displacement accuracy, position feedback accuracy, pointing accuracy, control of moving part clearances, assembly, and thermal stress.

[0003] Currently, the most classic structure for focusing mechanisms of reflectors is motor drive, gear and ball screw transmission, and double-row linear guide rails. This type of focusing mechanism is complex, has many components, and is difficult to meet the requirements of lightweight design, so it is mostly used for small-diameter reflectors. In addition, the motion transmission and guidance used in existing reflector focusing mechanisms are mostly statically indeterminate constraints. This method requires high precision in machining and assembly. When the size of the reflector being loaded is large, it is difficult to guarantee motion accuracy, and the assembly is susceptible to internal stress caused by temperature changes, which is not conducive to maintaining the stability of the reflector's position and surface shape. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the inventors have conducted intensive research and provided a lightweight quasi-statically fixed focusing mechanism and focusing method for a space camera. On the one hand, the focusing mechanism has a simple composition, can support large-sized reflector components, and achieves a lightweight design. On the other hand, it is easy to process and assemble, can isolate deformation transmission, and reduce the adverse effects of structural deformation caused by assembly and thermal stress on the accuracy of the reflector.

[0005] The technical solution provided by this invention is as follows:

[0006] In a first aspect, a lightweight quasi-statically fixed focusing mechanism for a space camera includes a focusing base, a main support, a sliding base, a drive mechanism, and a transmission mechanism.

[0007] The focusing base and the sliding base are located on both sides of the main support and are respectively installed on the main load-bearing structure of the space camera. The focusing base and the main support form a cylindrical guide pair, and the sliding base and the main support form a planar guide pair.

[0008] The main support carries the reflector assembly and provides an installation interface for the reflector assembly. A drive mechanism and a transmission mechanism are installed on it. The drive mechanism drives the transmission mechanism to operate, causing the main support to move relative to the focusing base and the sliding base, thereby performing focusing.

[0009] Furthermore, the focusing base is equipped with two hollow tubular optical axis guides arranged in a straight line, namely the first optical axis guide and the second optical axis guide. The optical axis guides and the structure on the main support form a cylindrical guide pair to provide guidance for the main support.

[0010] Furthermore, a guide block is installed on the side of the main support facing the sliding base, and a U-shaped guide groove with a lateral opening is machined on the side of the sliding base facing the main support. The guide block and the U-shaped guide groove cooperate to form a planar guide pair, providing motion guidance for the main support.

[0011] Furthermore, a drive mechanism, a transmission mechanism, and two linear bearings arranged in a straight line front to back are installed on the side of the main support facing the focusing base. The drive mechanism is a stepper motor, and the transmission mechanism includes an adaptive coupling, a ball screw, and a ball nut. The output shaft of the stepper motor is connected to the ball screw through the adaptive coupling. The ball screw and the ball nut cooperate to form a transmission pair. The ball nut is installed between the first optical axis guide rail and the first optical axis guide rail on the focusing base. When the stepper motor runs, it drives the ball screw to rotate. The ball screw generates linear motion relative to the ball nut, which drives the main support to move back and forth and generates a back and forth displacement relative to the focusing base.

[0012] Furthermore, a sensor positioning seat is installed on the side of the main support facing the focusing base, and a sensor connecting rod is installed on the sensor positioning seat. The sensor connecting rod is fixedly connected to the inner connecting rod of the LVDT sensor, and the outer connecting rod of the LVDT sensor is installed in the second optical axis guide rail, with its axis coaxial with the second optical axis guide rail. When the main support moves, the sensor positioning seat drives the inner connecting rod of the LVDT sensor to move, and the inner and outer connecting rods of the LVDT sensor generate relative displacement, which can provide feedback on the actual movement of the main support mechanism.

[0013] Furthermore, the guide block installed on the side of the main support facing the sliding base includes a sliding seat, a radial spherical bearing, and a sliding seat support shaft. The sliding seat support shaft is fixedly connected to the main support, and the sliding seat support shaft is fixedly connected to the inner hole of the radial spherical bearing. The outer ring of the radial spherical bearing is fixedly connected to the inner hole of the sliding seat. The upper and lower sides of the sliding seat are planar structures. Preferably, countersunk holes are formed in the planar structures on both sides, and sliding inserts are bonded to the countersunk holes on both sides. The sliding inserts contact the upper and lower inner planes of the U-shaped guide groove of the sliding base. Preferably, the sliding inserts are made of polyimide material.

[0014] Furthermore, the adaptive coupling includes a steering sleeve A, two steering sleeves B, four rotating shafts A and two rotating shafts B. The rotating shafts A radially pass through the through holes reserved on the steering sleeves A and B, fixing the two steering sleeves B into the steering sleeve A. The rotating shafts A and steering sleeves B are clearance-fitted, and the rotating shafts A and steering sleeves A are interference-fitted. The steering sleeves B are embedded in the inner hole of the steering sleeve A, with radial clearance, which enables the rotation and radial translation of the steering sleeves B relative to the steering sleeves A.

[0015] Two radial through holes are symmetrically arranged on steering sleeve A and steering sleeve B in a direction orthogonal to shaft A. Shaft B is installed in the through holes. Shaft B is interference-fitted with steering sleeve B and clearance-fitted with steering sleeve A. The output shaft of the stepper motor and the input end of the ball screw extend into the adaptive coupling. One shaft B passes through the radial hole of the stepper motor output shaft, and the other shaft B passes through the radial hole of the ball screw input end, realizing torque transmission and axial connection between the stepper motor shaft and the ball screw.

[0016] Furthermore, the adaptive coupling also includes an elastic retaining ring C, which is fitted onto the steering sleeve A and is positioned through the through holes of the four rotating shafts A and two rotating shafts B on the steering sleeve A, thereby pressing the outer free ends of the rotating shafts A and B.

[0017] Secondly, a lightweight quasi-statically fixed focusing method for a space camera, employing the lightweight quasi-statically fixed focusing mechanism for a space camera described in the first aspect, includes the following steps:

[0018] Install the reflector assembly on the main support;

[0019] The focusing base and the sliding base are located on both sides of the main support and are respectively installed on the main load-bearing structure of the space camera. The focusing base and the main support form a cylindrical guide pair, and the sliding base and the main support form a planar guide pair.

[0020] When the optical system of the space camera defocuses, the drive mechanism is activated. The drive mechanism drives the transmission mechanism to operate, causing the main support to shift relative to the focusing base and the sliding base, thereby achieving focusing.

[0021] The lightweight quasi-statically fixed focusing mechanism and focusing method for a space camera provided by the present invention have the following beneficial effects:

[0022] 1. The present invention provides a lightweight quasi-statically fixed focusing mechanism and focusing method for a space camera, which adopts stepper motor drive, ball screw transmission, linear bearing and planar motion guide, and LVDT sensor feedback mechanism position. The components are simple and lightweight, and can be easily made lightweight when applied to large-size reflector components.

[0023] 2. The present invention provides a lightweight quasi-statically determinate focusing mechanism and focusing method for a space camera. It adopts a statically determinate support motion configuration of cylindrical joint combined with planar joint. The cylindrical joint is guided by linear bearings and optical axis guide rails, and the planar joint is guided by radial joint bearings and square cavity fit. It can effectively avoid the influence of internal stress caused by redundant kinematic constraints on the pose and surface stability of large-sized reflectors due to mechanism assembly, operation and temperature changes.

[0024] 3. The present invention provides a lightweight quasi-statically determinate focusing mechanism and focusing method for a space camera. The adaptive coupling can release radial translation and rotational degrees of freedom, realize torque transmission and axial connection between the stepper motor shaft and the ball screw, and effectively avoid motion interference, jamming or decrease in accuracy caused by machining and assembly errors in the drive link, transmission link and guide link.

[0025] 4. The present invention provides a lightweight quasi-statically fixed focusing mechanism and focusing method for a space camera. Support rod A provides auxiliary support for the focusing base, and support rod B provides auxiliary support for the sliding base. Both are connected to the foot by adhesive. While improving the rigidity of the support structure, only a small amount of weight is added. Moreover, stress-free assembly further avoids the transmission of structural deformation to optical elements.

[0026] 5. The present invention provides a lightweight quasi-statically determinate focusing mechanism and focusing method for a space camera. The focusing mechanism is statically determinate in principle through the design of the degree of freedom of the guiding and transmission links. Therefore, the running resistance is small. Moreover, due to the simple transmission links and low friction, the motor drive efficiency is high under the weightless state of space operation. Attached Figure Description

[0027] Figure 1 This is a simplified kinematic diagram of the focusing mechanism of the lightweight statically fixed mirror of the space camera of the present invention;

[0028] Figure 2 This is a perspective view of the focusing mechanism of the lightweight statically fixed mirror of the space camera of the present invention;

[0029] Figure 3 This is a front view of the focusing mechanism of the lightweight statically fixed mirror for the space camera of the present invention;

[0030] Figure 4 This is a cross-sectional view AA of the focusing mechanism of the lightweight statically fixed mirror of the space camera of the present invention;

[0031] Figure 5 This is a partial cross-sectional view of the focusing mechanism of the lightweight statically fixed mirror of the space camera of the present invention.

[0032] Figure 6 This is a cross-sectional view of the adaptive coupling of the focusing mechanism for the lightweight statically fixed mirror of the space camera according to the present invention.

[0033] Explanation of icon numbers:

[0034] 01-Plane guide pair, 02-Cylindrical guide pair, 1-Focusing base, 2-Support rod A, 3-Main body support, 4-Foot seat, 5-Support rod B, 6-Sliding base, 7-Cylindrical pin, 81-First optical axis guide rail, 82-Second optical axis guide rail, 9-Linear bearing, 10-Elastic retaining ring A, 11-Ball screw nut, 12-Ball screw, 13-Adaptive coupling, 14-Stepper motor, 15-LVDT sensor, 16-Sensor connecting rod, 17-Sensor positioning seat, 18-Rubber pad, 19-Limit stop, 20-Sliding seat, 21-Sliding insert, 22-Radial spherical bearing, 23-Sliding seat support shaft, 24-Elastic retaining ring B, 25-Swivel sleeve A, 26-Rotating shaft A, 27-Swivel sleeve B, 28-Rotating shaft B. Detailed Implementation

[0035] The features and advantages of the present invention will become clearer and more apparent from the following detailed description.

[0036] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments. Although various aspects of embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated otherwise.

[0037] This invention provides a lightweight quasi-statically fixed focusing mechanism for a space camera, comprising a focusing base 1, a main support 3, and a sliding base 6. The focusing base 1 and the sliding base 6 are the mounting and fixing support structures of the entire mechanism, located on both sides of the main support 3 and respectively installed onto the main load-bearing structure of the space camera. The focusing base 1 is connected to one end of a support rod A2, and the other end of the support rod A2 is installed onto the main load-bearing structure of the space camera via a foot 4. The support rod A2 provides auxiliary support for the focusing base 1, improving structural rigidity. The sliding base 6 is connected to one end of a support rod B5, and the other end of the support rod B5 is installed onto the main load-bearing structure of the space camera via a foot 4. The support rod B5 provides auxiliary support for the sliding base 6.

[0038] The focusing base 1 is equipped with two hollow tubular optical axis guides arranged in a straight line, namely the first optical axis guide 81 and the second optical axis guide 82. A ball screw nut 11 is installed between the two optical axis guides. The two optical axis guides and the ball screw nut 11 are coaxial. The two optical axis guides and the structure on the main body support 3 form a cylindrical guide pair 02, which provides guidance for the moving part main body support 3. The ball screw nut 11 provides transmission for the main body support 3.

[0039] The sliding base 6 has a U-shaped guide groove with a side opening on the side facing the main support 3, which forms a planar guide pair 01 with the guide block on the main support 3 to provide motion guidance for the main support 3.

[0040] The main support 3 is the largest moving part of the entire mechanism. It houses drive, transmission, and guide components to support the reflector assembly and provide a high-precision mounting interface. On one side of the main support 3 (facing the focusing base 1), a stepper motor 14, a sensor positioning seat 17, and two linear bearings 9 arranged in a straight line are mounted. The stepper motor 14 is the drive mechanism, the sensor positioning seat 17 assists in the installation of the LVDT sensor 15, and the linear bearings 9 are the guide mechanism, cooperating with the two optical axis guide rails 8 to form a cylindrical guide pair 02. On the other side (facing the sliding base 6), a guide block is mounted to cooperate with the U-shaped guide groove of the sliding base 6 to form a planar guide pair 01.

[0041] Stepper motor 14 serves as the drive mechanism for the focusing mechanism. Its output shaft is connected to ball screw 12 via adaptive coupling 13. Ball screw 12 and ball nut 11 cooperate to form a transmission pair. When stepper motor 14 operates, it drives ball screw 12 to rotate. Ball nut 11 is fixed to the focusing base 1 and does not move. Ball screw 12 drives the main support 3 and its upper structure to move back and forth linearly, producing a back and forth displacement relative to the focusing base 1.

[0042] A sensor link 16 is mounted on the sensor positioning seat 17. The sensor link 16 is fixedly connected to the inner link of the LVDT sensor 15. The outer link of the LVDT sensor 15 is installed inside the second optical axis guide rail 82, and its axis is coaxial with the second optical axis guide rail 82. When the main support 3 moves, the sensor positioning seat 17 drives the inner link of the LVDT sensor 15 to move, and the inner and outer links of the LVDT sensor 15 generate relative displacement, which can provide feedback on the actual movement of the main support 3 mechanism.

[0043] The guide block includes a sliding seat 20, a radial spherical bearing 22, and a sliding seat support shaft 23. The sliding seat support shaft 23 is fixedly connected to the main support 3 and to the inner hole of the radial spherical bearing 22. The outer ring of the radial spherical bearing 22 is fixedly connected to the inner hole of the sliding seat 20. The upper and lower sides of the sliding seat 20 are planar structures. Preferably, countersunk holes are formed in the planar structures on both sides, and sliding inserts 21 are bonded to the countersunk holes on both sides. After the guide block and the U-shaped guide groove of the sliding base 6 cooperate to form a planar guide pair 01, the sliding inserts 21 reduce sliding friction. The sliding inserts 21 are preferably made of polyimide material to achieve vacuum anti-cold welding effect.

[0044] Cylindrical guide pair 02 and planar guide pair 01 are located on both sides of the main support 3, with the former constraining... Figure 1 The cylindrical joint shown in Figure 02 has a total of 4 degrees of freedom, including translation in two directions and rotation in two directions, with the latter constrained. Figure 1 The 01 planar pair shown has 1 degree of freedom perpendicular to the plane direction, and the entire structure has exactly 1 degree of freedom remaining in the direction of motion, forming a statically determinate guiding and focusing mechanism.

[0045] Two limiting blocks 19 are installed between the two optical axis guide rails on the focusing base 1. Rubber pads 18 are attached to the limiting blocks 19 to interfere with the upper structural components (the main support structure supporting the stepper motor 14 when moving forward, and the stepper motor 14 when moving backward) when the main support 3 moves to the set limit position, thereby limiting the stroke of the main support 3.

[0046] The adaptive coupling 13 includes a steering sleeve A25, two steering sleeves B27, four rotating shafts A26, two rotating shafts B28, and two elastic retaining rings C29. The rotating shafts A26 radially pass through the through holes reserved on the steering sleeves A25 and B27, fixing the two steering sleeves B27 into the steering sleeve A25. The rotating shafts A26 and B27 are clearance-fitted, and the rotating shafts A26 and A25 are interference-fitted. The steering sleeves B27 are embedded in the inner hole of the steering sleeves A25, with radial clearance, which allows the steering sleeves B27 to rotate relative to the steering sleeves A25 and translate radially.

[0047] Two radial through holes are symmetrically arranged on steering sleeves A25 and B27 in a direction orthogonal to the rotating shaft A26. A rotating shaft B28 is installed within these through holes. The rotating shaft B28 is interference-fitted with steering sleeve B27 and clearance-fitted with steering sleeve A25. The output shaft of stepper motor 14 and the input end of ball screw 12 extend into adaptive coupling 13. One rotating shaft B28 passes through the radial hole of the stepper motor 14's output shaft, and the other rotating shaft B28 passes through the radial hole of the ball screw 12's input end. Adaptive coupling 13 enables torque transmission and axial connection between the stepper motor 14 shaft and the ball screw 12, effectively preventing motion jamming or accuracy degradation in the drive, transmission, and guiding components due to machining and assembly errors.

[0048] The elastic retaining ring C29 is fitted onto the steering sleeve A25, and its position passes through the through holes of the four rotating shafts A26 and two rotating shafts B28 on the steering sleeve A25. It presses the outer free ends of the rotating shafts A26 and B28 to prevent the rotating shafts A26 and B28 from coming out of the adaptive coupling.

[0049] This invention employs several mechanisms to control clearance, including: the sliding insert 21, after being assembled into the sliding seat 20, is matched with the dimensions of the square cavity of the sliding base 6 to control the clearance of the focusing mechanism at the planar joint. The linear bearing 9 and the optical axis guide rail have a slight interference fit to eliminate clearance at the cylindrical joint. The focusing base 1 and the two optical axis guide rails are respectively positioned and connected by two cylindrical pins 7, and the mating surfaces are fixed with structural adhesive. When the linear bearing 9 is installed on the main support 3, the two ends of the linear bearing 9 are axially limited by elastic retaining rings A10, and the mating surfaces of the main support 3 and the linear bearing 9 are fixed with structural adhesive. When the sliding seat support shaft 23 is installed on the main support 3, the two ends of the sliding seat support shaft 23 extending out of the main support 3 are axially limited by elastic retaining rings B24, and the mating surfaces of the main support 3 and the sliding seat support shaft 23 are fixed with structural adhesive.

[0050] The two ends of the support rod A2 are bonded and fixed to the focusing base 1 and the foot 4 respectively with structural adhesive. One end of the support rod B5 is connected and fixed to the sliding base 6 with screws or other threaded connectors, and the other end is bonded and fixed to the foot 4 with structural adhesive. This method can achieve stress-free installation of the focusing mechanism.

[0051] In this invention, the focusing mechanism is designed to weigh 4kg, and the weight of the reflector assembly it carries is 8.9kg. When the reflector diameter is 410mm×384mm, the following indicators were obtained through testing: movement and feedback accuracy is 0.005mm, the change in the reflector optical axis angle is less than 10 seconds within the entire 20mm travel range, the change in reflector position is less than 0.03mm and the change in angle is less than 3 seconds under space environment test conditions, and the installation and operation of the mechanism have no impact on the reflector surface shape. It has been verified by in-orbit flight.

[0052] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

[0053] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A lightweight quasi-statically fixed focusing mechanism for a space camera, characterized in that, It includes a focusing base (1), a main support (3), a sliding base (6), a drive mechanism, and a transmission mechanism; The focusing base (1) and the sliding base (6) are located on both sides of the main support (3) and are respectively installed on the main load-bearing structure of the space camera. The focusing base (1) and the main support (3) form a cylindrical guide pair (02), and the sliding base (6) and the main support (3) form a planar guide pair (01). The main support (3) carries the reflector assembly and provides an installation interface for the reflector assembly. A drive mechanism and a transmission mechanism are installed on it. The drive mechanism drives the transmission mechanism to operate, causing the main support (3) to move relative to the focusing base (1) and the sliding base (6) to perform focusing. The main support (3) is equipped with a drive mechanism, a transmission mechanism, and two linear bearings (9) arranged in a straight line at the front and back on the side facing the focusing base (1). The drive mechanism is a stepper motor (14), and the transmission mechanism includes an adaptive coupling (13), a ball screw (12), and a ball nut (11). The output shaft of the stepper motor (14) is connected to the ball screw (12) through the adaptive coupling (13). The ball screw (12) and the ball nut (11) cooperate to form a transmission pair. The ball nut (11) is installed between the first optical axis guide rail (81) and the second optical axis guide rail (82) on the focusing base (1). When the stepper motor (14) runs, it drives the ball screw (12) to rotate. The ball screw (12) generates linear motion relative to the ball nut (11), which drives the main support (3) to move back and forth and generates a back and forth displacement relative to the focusing base (1).

2. The lightweight quasi-static focusing mechanism for a space camera according to claim 1, characterized in that, The focusing base (1) is equipped with two hollow tubular optical axis guides arranged in a straight line, namely the first optical axis guide (81) and the second optical axis guide (82). The optical axis guides and the structure on the main support (3) form a cylindrical guide pair (02) to provide guidance for the main support (3).

3. The lightweight quasi-static focusing mechanism for a space camera according to claim 1, characterized in that, The main support (3) has a guide block installed on the side facing the sliding base (6). The sliding base (6) has a U-shaped guide groove with a side opening on the side facing the main support (3). The guide block and the U-shaped guide groove cooperate to form a planar guide pair (01) to provide motion guidance for the main support (3).

4. The lightweight quasi-static focusing mechanism for a space camera according to claim 1, characterized in that, A sensor positioning seat (17) is installed on the side of the main support (3) facing the focusing base (1). A sensor connecting rod (16) is installed on the sensor positioning seat (17). The sensor connecting rod (16) is fixedly connected to the inner connecting rod of the LVDT sensor (15). The outer connecting rod of the LVDT sensor (15) is installed in the second optical axis guide rail (82), and its axis is coaxial with the second optical axis guide rail (82). When the main support (3) moves, the sensor positioning seat (17) drives the inner connecting rod of the LVDT sensor (15) to move. The inner and outer connecting rods of the LVDT sensor (15) generate relative displacement, which can provide feedback on the actual movement of the main support (3) mechanism.

5. The lightweight quasi-static focusing mechanism for a space camera according to claim 1, characterized in that, The guide block installed on the side of the main support (3) facing the sliding base (6) includes a sliding seat (20), a radial joint bearing (22), and a sliding seat support shaft (23). The sliding seat support shaft (23) is fixedly connected to the main support (3), and the sliding seat support shaft (23) is fixedly connected to the inner hole of the radial joint bearing (22). The outer ring of the radial joint bearing (22) is fixedly connected to the inner hole of the sliding seat (20). The upper and lower sides of the sliding seat (20) are planar structures, and countersunk holes are opened in the planar structures on both sides. Sliding inserts (21) are bonded in the countersunk holes on both sides. The sliding inserts (21) contact the upper and lower inner planes of the U-shaped guide groove of the sliding base (6).

6. The lightweight quasi-static focusing mechanism for a space camera according to claim 5, characterized in that, The sliding insert (21) is made of polyimide material.

7. The lightweight quasi-static focusing mechanism for a space camera according to claim 3, characterized in that, The adaptive coupling (13) includes a steering sleeve A (25), two steering sleeves B (27), four rotating shafts A (26) and two rotating shafts B (28). The rotating shafts A (26) radially pass through the through holes reserved on the steering sleeves A (25) and B (27), fixing the two steering sleeves B (27) inside the steering sleeves A (25). The rotating shafts A (26) and B (27) are clearance-fitted, and the rotating shafts A (26) and A (25) are interference-fitted. The steering sleeves B (27) are embedded in the inner hole of the steering sleeves A (25), with radial clearance, which enables the rotation and radial translation of the steering sleeves B (27) relative to the steering sleeves A (25). Two radial through holes are symmetrically arranged on steering sleeve A (25) and steering sleeve B (27) in a direction orthogonal to shaft A (26). Shaft B (28) is installed in the through holes. Shaft B (28) is interference-fitted with steering sleeve B (27) and shaft B (28) is clearance-fitted with steering sleeve A (25). The output shaft of stepper motor (14) and the input end of ball screw (12) extend into adaptive coupling (13). One shaft B (28) passes through the radial hole of the output shaft of stepper motor (14) and the other shaft B (28) passes through the radial hole of the input end of ball screw (12), realizing torque transmission and axial connection between the shaft of stepper motor (14) and ball screw (12).

8. The lightweight quasi-static focusing mechanism for a space camera according to claim 3, characterized in that, The adaptive coupling (13) also includes an elastic retaining ring C (29), which is fitted onto the steering sleeve A (25). The position of the elastic retaining ring C (29) passes through the through holes of the four rotating shafts A (26) and two rotating shafts B (28) on the steering sleeve A (25), and presses the outer free ends of the rotating shafts A (26) and B (28).

9. A lightweight quasi-static focusing method for a space camera, characterized in that, The lightweight quasi-statically fixed focusing mechanism for a space camera as described in any one of claims 1 to 8 comprises the following steps: Install a reflector assembly on the main support (3); The focusing base (1) and the sliding base (6) are located on both sides of the main support (3) and are respectively installed on the main load-bearing structure of the space camera. The focusing base (1) and the main support (3) form a cylindrical guide pair (02), and the sliding base (6) and the main support (3) form a planar guide pair (01). When the optical system of the space camera defocuses, the drive mechanism is activated, which drives the transmission mechanism to operate, causing the main support (3) to shift relative to the focusing base (1) and the sliding base (6) to perform focusing.

Images