A spatial optical focusing platform

Abstract

This invention discloses a space optical focusing platform, comprising a base, a motor drive assembly, a reversing transmission assembly, a harmonic reduction transmission assembly, and a cylindrical cam focusing assembly. The base serves as the mounting carrier. The motor drive assembly is fixed to the base, with its power output axis arranged perpendicularly to the main optical axis of the focusing platform. The input end of the reversing transmission assembly is connected to the output shaft of the motor drive assembly, and the output end is a wave generator coaxially arranged. The harmonic reduction transmission assembly includes a rigid wheel housing fixed to the base and a flexible wheel rotating outer cylinder, a thin-walled flexible bearing sleeved on the wave generator, and transmission teeth meshing with the inner teeth of the rigid wheel housing on the outer wall of the flexible wheel rotating outer cylinder. A spiral cam groove is machined on the inner wall of the flexible wheel rotating outer cylinder. The cylindrical cam focusing assembly includes a telescopic inner cylinder and a transmission pin. The telescopic inner cylinder is used to support the optical lens, and an axial guide structure is provided between the telescopic inner cylinder and the base. One end of the transmission pin is fixed to the telescopic inner cylinder, and the other end is embedded in the spiral cam groove.

Description

Technical Field

[0001] This invention relates to the field of space optical precision focusing technology, and in particular to a high-precision, low-power harmonic focusing platform based on a cylindrical cam structure for use in optical components of space payloads. It can operate stably in the extreme environments of space vacuum and low temperature, providing key technical support for high-resolution space remote sensing imaging. Background Technology

[0002] In recent years, high-resolution space remote sensing imaging technology has become the core of development in the aerospace field. As a key part of the remote sensing imaging system, the focusing device of the space payload optical component directly determines the imaging quality and on-orbit reliability. It puts forward extreme requirements for lightweight, low power consumption, high precision and adaptability to extreme environments. At the same time, it needs to have autonomous focusing capability to meet the engineering needs of unattended space operations.

[0003] Currently, traditional space optical focusing devices used in China's aerospace field have several core defects: In terms of weight, traditional steel modules, excluding motors and lenses, weigh over 200g, significantly reducing the limited payload capacity and increasing spacecraft launch costs; in terms of power consumption, traditional devices rely on electromagnetic braking to achieve focusing lock, with standby power consumption reaching 100-150mW, while space optical component focusing devices spend approximately 60% of their time in locked standby mode, consuming valuable onboard energy; in terms of accuracy, traditional mechanical transmission suffers from frictional losses and mechanical backlash, and is prone to structural deformation and component adhesion in the vacuum and low-temperature environment of space, causing focusing accuracy to drift to ±20 micrometers or more, failing to meet the high-precision requirements of high-resolution remote sensing imaging; in terms of environmental adaptability, some civilian-modified focusing devices have not undergone vacuum resistance, low outgassing, and wide-temperature treatment, making them prone to lubricant evaporation, component cracking, jamming, and other failures in orbit, resulting in low reliability.

[0004] Although new focusing technologies such as space-grade electro-focusing and liquid lenses have emerged internationally, reducing weight by 30%-40% compared to traditional steel modules and lowering standby power consumption to 50mW, with focusing accuracy reaching ±10 micrometers at room temperature, significant shortcomings remain: the lightweight design does not match the extreme weight requirements of space payloads, resulting in high standby power consumption and low onboard energy utilization efficiency; poor low-temperature adaptability, prone to lens phase transitions and transmission mechanism jamming in the ultra-low temperature environment of -196℃ in space, making long-term stable operation impossible; at the same time, imported space-grade focusing devices have poor compatibility, making them difficult to integrate with domestic space payload optical components, resulting in extremely high procurement and on-orbit maintenance costs, as well as technical barriers that prevent large-scale engineering applications.

[0005] Overall, existing focusing devices, both domestically and internationally, have not solved the core problems of deeply integrating lightweight, low power consumption, high precision, and adaptability to the extreme environment of space. They also cannot meet the needs of autonomous focusing and engineered assembly of space payloads. The aerospace field urgently needs a space optical focusing platform that innovates in all dimensions, including materials, transmission, structure, and environmental adaptation. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of existing technologies and solve the problems of large weight, high standby power consumption, low focusing accuracy, poor adaptability to extreme environments, and lack of autonomous focusing capability in existing space focusing devices. This invention provides a space optical focusing platform that achieves extreme lightweight design, low standby power consumption, micron-level high-precision focusing, long-term stable operation in extreme vacuum / low-temperature environments, autonomous focusing capability, and adaptability to the installation and use requirements of space payload optical components. It forms a comprehensive aerospace environment adaptability design from materials and structure to transmission, meeting engineering application requirements and providing key technical support for high-resolution space remote sensing imaging.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] A space optical focusing platform, the focusing platform comprising:

[0009] The base serves as the mounting platform;

[0010] The motor drive assembly is fixed to the base, and its power output axis is arranged perpendicular to the main optical axis of the focusing platform.

[0011] The reversing transmission assembly has its input end connected to the output shaft of the motor drive assembly, and its output end is a wave generator arranged coaxially.

[0012] A harmonic speed reduction transmission assembly includes a rigid wheel housing fixed to the base and a flexible wheel rotating outer cylinder, a thin-walled flexible bearing sleeved on the wave generator, transmission teeth meshing with the inner teeth of the rigid wheel housing on the outer wall of the flexible wheel rotating outer cylinder, and a helical cam groove machined on the inner wall of the flexible wheel rotating outer cylinder; and...

[0013] A cylindrical cam focusing assembly includes a telescopic inner cylinder and a drive pin. The telescopic inner cylinder is used to carry an optical lens. An axial guide structure is provided between the telescopic inner cylinder and the base to restrict the circumferential rotational freedom of the telescopic inner cylinder. One end of the drive pin is fixed to the telescopic inner cylinder, and the other end is embedded in the spiral cam groove.

[0014] Furthermore, the reversing transmission assembly includes a motor bevel gear and a wave generator bevel gear that mesh with each other. The motor bevel gear is fixed to the output shaft of the motor drive assembly, and the wave generator bevel gear is coaxially fixed with the wave generator. The wave generator has an elliptical cam structure.

[0015] Furthermore, the motor bevel gear, the wave generator bevel gear, and the wave generator are all made of polyetheretherketone (PEEK) material.

[0016] Furthermore, the flexible wheel rotating outer cylinder is made of 7075-T6 aluminum alloy, and the flexible wheel rotating outer cylinder is provided with a part of the working side cylinder wall for setting the spiral cam groove.

[0017] Furthermore, the base is a ring structure, including an inner ring, an outer ring, and protrusions. The inner ring and the outer ring are connected by several connecting rods. The inner wall of the inner ring is provided with several protrusions at equal intervals, and vertical grooves are formed between pairs of protrusions. The outer wall of the telescopic inner cylinder is provided with a slider that cooperates with the vertical groove. The vertical groove and the slider together constitute an axial guide structure, and the material has self-lubricating properties, so no lubricant is needed on the guide surface of the axial guide structure.

[0018] Furthermore, both the base and the telescopic inner cylinder are made of modified polypropylene (PP) copolymer.

[0019] Furthermore, the outer shell of the rigid wheel is made of nylon PA, and the surface of the outer shell of the rigid wheel is provided with a honeycomb-shaped hollow weight-reducing structure.

[0020] Furthermore, the motor drive assembly includes a servo motor, which has a built-in absolute magnetic encoder.

[0021] Furthermore, the outer periphery of the flexible wheel rotating outer cylinder is rotatably supported and connected to the rigid wheel housing via a thin-walled deep groove ball bearing.

[0022] The present invention also provides a working method based on the aforementioned space optical focusing platform, comprising:

[0023] When the control system issues a focusing command, the servo motor of the motor drive component starts to rotate, driving the motor bevel gear to rotate synchronously. Through meshing transmission, the power is transmitted to the wave generator bevel gear, completing a 90° vertical power reversal and initial deceleration.

[0024] The bevel gear of the wave generator drives the coaxially fixed wave generator to rotate. The wave generator forces the outer cylinder of the flexible wheel to undergo periodic elastic deformation through the thin-walled flexible bearing, so that the outer teeth of the outer cylinder of the flexible wheel mesh with the inner teeth of the rigid wheel shell in sequence, completing the harmonic speed reduction transmission and converting the high-speed, low-torque rotation output by the motor into low-speed, high-torque rotation.

[0025] When the flexible wheel rotates and the outer cylinder rotates, the cam groove on its cylinder wall rotates synchronously, forcing the transmission pin embedded in the cam groove to produce axial displacement, which in turn drives the telescopic inner cylinder to make axial linear motion along the axial guide structure of the base 1, thereby realizing the focusing of the lens.

[0026] Compared with the prior art, the beneficial effects of the technical solution of the present invention are:

[0027] 1. This invention achieves integration of the flexible wheel and cam by directly machining a spiral cam groove on the side wall of the flexible wheel rotating outer cylinder, reducing the connecting flange and fasteners between the flexible wheel cylinder and the cam cylinder in traditional focusing mechanisms, and simplifying the transmission chain. In addition, through the selection of aerospace-grade lightweight materials and optimization of the hollow structure, the overall weight of the device without motor and lens is less than 130g, which is more than 60% lighter than traditional space steel focusing modules. This significantly reduces the weight occupation of the space payload and reduces the launch cost of spacecraft. At the same time, the lightweight structure can reduce the impact of micro-vibrations in space on focusing accuracy.

[0028] 2. The large transmission ratio (50:1) of the harmonic drive component is superimposed with the initial reduction ratio (8:5) of the commutation component, resulting in a total transmission ratio of 80:1, which increases the output torque by about 80 times. At the same time, the harmonic drive has zero backlash, zero frictional sliding, and a transmission efficiency of over 95%. It saves more than 30% energy compared to traditional mechanical transmission friction loss. In addition, both the bevel gear and the harmonic drive adopt a vacuum-resistant low-temperature design to ensure long-term on-orbit transmission reliability. The vertical layout of the bevel gear solves the problem of the motor's excessive axial length obstructing the lens's field of view, resulting in a more compact structure that meets the compact installation requirements of space optical components.

[0029] 3. The motor output shaft and the main optical axis are arranged in a perpendicular orthogonal layout, which changes the traditional longitudinal configuration of the drive motor extending along the optical axis, and avoids the rear end of the motor from intruding into or blocking the effective imaging field of the lens; it shortens the axial dimension of the system, making the structure more compact and adaptable to the compact installation space of the effective load.

[0030] 4. The motor gears and wave generator gears are made of PEEK material; the material has self-lubricating properties, and no lubricant is needed on the guide surface of the axial guide structure, completely eliminating the high volatility and overflow effect of traditional liquid / gas grease in the high vacuum environment of space, preventing adhesion and wear resistance; the bearings are filled with solid grease to ensure that the focusing platform can work for a long time without jamming or precision drift in an extreme wide temperature and high vacuum environment of -90℃ to +120℃.

[0031] 5. The outer shell of the rigid wheel is designed with a honeycomb-shaped perforation; the outer cylinder of the flexible wheel has redundant cylinder wall removed from the non-working side; the inner cylinder wall thickness is mechanically reduced; under the premise of strictly ensuring the rigidity of the aerospace-grade vibration and impact-resistant structure, redundant materials in the non-stress core area are precisely removed; achieving a perfect balance between lightweight and structural rigidity.

[0032] 6. By combining the zero backlash characteristic of harmonic drive with the built-in 17-bit multi-turn absolute magnetic encoder of the motor, a precision focusing accuracy of ±10μm is achieved. The one-time focusing avoids the extra energy consumption of repeated focusing, thereby improving the imaging quality and indirectly reducing the system energy consumption.

[0033] 7. The base is equipped with a standard installation interface for space payloads. The overall structure is compatible with mainstream domestic space payload optical components, allowing for rapid assembly without major modifications to the equipment. The core components are all domestically produced aerospace-grade selected, breaking through the compatibility, cost and technical barriers of imported devices. It can be applied on a large scale in engineering to various space optical missions such as high-resolution space remote sensing imaging and aerospace optical detection. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the overall structure of the optical focusing platform of the present invention;

[0035] Figure 2 This is a cross-sectional assembly diagram of the optical focusing platform of the present invention;

[0036] Figure 3 This is an exploded view of the optical focusing platform of the present invention;

[0037] Figure 4 This is a schematic diagram of the harmonic deceleration transmission part of the present invention;

[0038] Figure 5 This is an enlarged structural schematic diagram of the cylindrical cam focusing part of the present invention;

[0039] Reference numerals: 1-Base; 1-1-Inner ring; 1-2-Outer ring; 1-3-Connecting rod; 1-4-Protrusion;

[0040] 2-Motor drive assembly; 2-1-Motor; 2-2-Motor bracket;

[0041] 3-Reversing transmission assembly; 3-1-Motor bevel gear; 3-2-Wave generator bevel gear; 3-3-Wave generator; 3-4-Motor gear retaining ring;

[0042] 4-Harmonic reduction gear transmission assembly; 4-1-Thin-walled flexible bearing; 4-2-Flexible wheel rotating outer cylinder; 4-2-1-Cam slide groove; 4-3-Rigid wheel housing;

[0043] 5-Cylindrical cam focusing assembly; 5-1-Drive pin; 5-2-Telescopic inner cylinder; 5-2-1-Slider; 6-Deep groove ball bearing; 7-Lens. Detailed Implementation

[0044] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

[0045] Example 1

[0046] See Figures 1 to 5 This embodiment provides a high-precision, high-load, low-power harmonic cylindrical cam space optical focusing platform, which is adapted to the installation of space payload optical components and the extreme environment of space vacuum and low temperature. The focusing platform includes a base 1, a motor drive assembly 2, a reversing transmission assembly 3, a harmonic reduction transmission assembly 4, and a cylindrical cam focusing assembly 5. The base 1 is the mounting carrier of the entire platform and is fixed at the bottom to the mounting position of the aerospace imaging equipment. The motor drive assembly 2 is fixed to the side wall of the base 1, and its power output axis is arranged perpendicularly to the main optical axis of the platform at 90°. The input end of the reversing transmission assembly 3 is connected to the output end of the motor drive assembly 2. The output shaft is connected to the harmonic reduction gear transmission assembly 4 to realize vertical reversal of power and initial deceleration; the rigid wheel housing 4-3 of the harmonic reduction gear transmission assembly 4 is fixedly connected to the base 1, and its output end is integrated with the flexible wheel rotating outer cylinder to realize large transmission ratio reduction and torque increase and zero backlash transmission; the telescopic inner cylinder of the cylindrical cam focusing assembly 5 cooperates with the base 1 through an axial guide structure to convert the rotational motion into axial linear motion along the main optical axis, realize the precise focusing of the optical lens, and ensure the stability of the optical axis during focusing; the motor automatically locks mechanically after focusing, with zero standby power consumption; and there is no jamming or precision drift in extreme environments.

[0047] Preferably, the motor drive assembly 2 includes a motor 2-1 and a motor bracket 2-2, wherein the motor 2-1 is fixedly connected to one side of the base 1 by the motor bracket 2-2 and screws.

[0048] Preferably, the reversing transmission assembly 3 includes a motor bevel gear 3-1, a wave generator bevel gear 3-2, and a wave generator 3-3 that mesh with each other; the motor bevel gear 3-1 is fixed to the output shaft of the motor 2-1 by a flat key and a motor gear retainer 3-4, and the wave generator bevel gear 3-2 and the wave generator 3-3 are coaxially fixed together; the transmission ratio of the two-stage bevel gears of the wave generator bevel gear 3-2 and the motor bevel gear 3-1 is 8:5. The motor bevel gear 3-1, the wave generator bevel gear 3-2, and the wave generator 3-3 are all made of PEEK material, which has a wide operating temperature range of -90℃ to +120℃, as well as self-lubricating, wear-resistant, low outgassing rate, and low density characteristics. It can operate stably without the need for grease, completely eliminating grease contamination and consumption; it meets the requirements of lubricant evaporation restrictions and low-temperature transmission in the space vacuum environment, and meets the requirements of aerospace vehicles for lubricant evaporation restrictions.

[0049] In this embodiment, the wave generator bevel gear 3-2 and the wave generator 3-3 are integrally set. The wave generator 3-3 is located in the middle and has an elliptical cam-shaped structure (the wave generator is an elliptical cylinder with a major axis of 36.7 mm and a minor axis of 34.9 mm). The wave generator bevel gear 3-2 is set on the outer edge. A baffle is provided between the wave generator bevel gear 3-2 and the wave generator 3-3. The baffle is used to embed a thin-walled flexible bearing 4-1.

[0050] Preferably, the harmonic reduction transmission assembly 4 includes a thin-walled flexible bearing 4-1, a flexible wheel rotating outer cylinder 4-2, and a rigid wheel housing 4-3; the thin-walled flexible bearing 4-1 is fitted on the outside of the wave generator 3-3, and its outer ring is tightly fitted with the inner wall of the flexible wheel rotating outer cylinder 4-2; the flexible wheel rotating outer cylinder 4-2 is a thin-walled cylindrical structure, and the outer wall is machined with transmission teeth, which mesh with the inner teeth of the rigid wheel housing 4-3 fixed to the base 1 to form a harmonic transmission pair. The harmonic transmission ratio of the harmonic reduction transmission assembly 4 is 50:1, and the total transmission ratio reaches 80:1 after being superimposed with the bevel gear transmission, and the output torque is increased by about 80 times compared with the direct drive of the motor;

[0051] The flexible wheel rotating outer cylinder 4-2 is a hollow columnar structure. The inner wall of the flexible wheel rotating outer cylinder 4-2 has a section of working side cylinder wall protruding out, and a cam groove 4-2-1 is opened on the working side cylinder wall. The material of the harmonic reduction transmission component 4 is 7075-T6 aluminum alloy. After low temperature aging treatment, the redundant cylinder wall of the non-working side without the cam groove 4-2-1 is removed, which takes into account high toughness, lightweight and low temperature deformation resistance. There is no tooth deformation under vacuum low temperature, ensuring the zero backlash characteristic of harmonic transmission.

[0052] The cam slide 4-2-1 is ground and stress-relieved to prevent slide deformation caused by alternating temperatures in space.

[0053] Preferably, the cylindrical cam focusing assembly 5 includes a transmission pin 5-1 and a telescopic inner cylinder 5-2; one end of the transmission pin 5-1 is movably embedded in the cam groove 4-2-1, and the other end is fixedly connected to the telescopic inner cylinder 5-2. The transmission pin 5-1 is a stainless steel transmission pin, which does not stick or wear under vacuum and low temperature; the telescopic inner cylinder 5-2 is the mounting carrier for the optical lens 7, and cooperates with the base 1 through an axial guide structure, and can only move axially in a straight line along the main optical axis of the platform; the material of the telescopic inner cylinder 5-2 is a low-temperature resistant modified PP copolymer, which has low gas release and resistance to low-temperature brittleness. The wall thickness is optimized and thinned through mechanical simulation, retaining only the necessary structure to achieve lightweighting, and does not brittle under low temperature, thus balancing lightweighting and low-temperature structural rigidity, providing a stable mounting and focusing carrier for the space optical component lens.

[0054] Example 2

[0055] This embodiment is based on Embodiment 1, and provides a detailed description of some of its components.

[0056] In this embodiment, the base 1 is made of PP copolymer, passes the low outgassing test, and is fixed to the mounting position of the space payload optical component using standard space bolts, providing stable mounting support for the entire platform. Furthermore, the base has a standard space payload mounting interface at its bottom, allowing for rapid assembly without significant modifications to the optical component, thus meeting engineering assembly requirements. See [link / reference]. Figure 3 The base 1 is a ring structure, including an inner ring 1-1, an outer ring 1-2, and protrusions 1-4. The inner ring 1-1 and the outer ring 1-2 are connected by several connecting rods 1-3. The inner wall of the inner ring 1-1 is provided with several protrusions 1-4 at equal intervals, and vertical grooves are formed between pairs of protrusions 1-4. The outer wall of the telescopic inner cylinder 5-2 is provided with a slider 5-2-1 that cooperates with the vertical groove. The vertical groove and the slider 5-2-1 together constitute an axial guide structure to restrict the rotational freedom of the telescopic inner cylinder 5-2, allowing it to only make axial linear movements along the main optical axis of the platform, thus ensuring the stability of the lens optical axis during focusing. The guide surface of the axial guide structure is provided with a self-lubricating coating. The guide surface includes the contact surface between the protrusions 1-4 and the slider 5-2-1, and the contact surface between the slider 5-2-1 and the inner ring 1-1.

[0057] Preferably, motor 2-1 adopts a PMM28 series 20W low-voltage micro servo motor, which is fixed to the side wall of base 1 by bolts. The motor output axis is arranged perpendicularly to the main optical axis of the platform at 90°, avoiding the problem of the motor's excessive axial length obstructing the effective field of view of the lens. The servo motor weighs only 0.17kg, has a built-in 17-bit multi-turn absolute magnetic encoder, supports CANopen or RS-485 bus control, has millisecond-level start / stop function, wide temperature range of -55℃ to +85℃, and autonomous position closed-loop control capability, enabling autonomous focusing in space and adapting to the vacuum environment of space. Combined with the zero backlash characteristic of harmonic drive, it achieves precise focusing with a repeatability accuracy of ±10μm. After focusing, the motor is electromagnetically braked, resulting in low standby power consumption and saving on-board energy.

[0058] Preferably, the thin-walled flexible bearing 4-1 of the harmonic reduction transmission assembly 4 is a thin-walled lightweight model, weighing about 30g, filled with solid grease, resistant to vacuum low temperature and extremely low volatility; the platform rotation support part adopts a thin-walled deep groove ball bearing 6, model 61707 aerospace grade modification, which has low rotational resistance and stable precision under vacuum low temperature. The two types of bearings are more than 50% lighter than conventional bearings of the same specification, and meet the requirements of long-life on-orbit use of space payloads.

[0059] The flexible rotating outer cylinder 4-2 is a thin-walled cylindrical structure made of 7075-T6 aluminum alloy. Harmonic drive teeth are machined on the outer wall, meshing with the internal teeth of the rigid wheel housing 4-3 fixed to the base 1 to form a harmonic drive pair with a transmission ratio of 50:1. The rigid wheel housing 4-3 is made of PA nylon, with a honeycomb-shaped perforated structure on its surface. The wave generator bevel gear 3-2 and the motor gear mounting area have partially perforated structures, precisely removing redundant material while ensuring structural rigidity and maximizing weight reduction.

[0060] Preferably, the transmission pin 5-1 is embedded in the cam groove 4-2-1, and the other end is fixed to the outer wall of the telescopic inner cylinder 5-2 by an interference fit. The telescopic inner cylinder 5-2 is a cylindrical structure made of PP copolymer, and the inner wall is provided with lens mounting positions. When the flexible wheel rotates and the outer cylinder 4-2 rotates at low speed, the cam groove 4-2-1 forces the transmission pin 5-1 to move along a helical track, thereby driving the telescopic inner cylinder 5-2 to move axially in a linear motion along the main optical axis, realizing precise focusing of the optical lens. The wall thickness of the telescopic inner cylinder 5-2 is reduced after optimization by mechanical simulation, further reducing the overall weight of the machine.

[0061] Example 3

[0062] Based on the same inventive concept, this application also provides a method for using the space optical focusing platform based on the above embodiments, specifically including the following:

[0063] When the control system issues a focusing command, the servo motor of the motor drive component 2 starts to rotate, driving the motor bevel gear 3-1 to rotate synchronously. Through meshing transmission, the power is transmitted to the wave generator bevel gear 3-2, completing a 90° vertical power reversal and initial deceleration, with a transmission ratio of 8:5.

[0064] The wave generator bevel gear 3-2 drives the coaxially fixed wave generator 3-3 to rotate. The wave generator 3-3 forces the flexible wheel to rotate through the thin-walled flexible bearing 4-1, causing the outer cylinder 4-2 to undergo periodic elastic deformation. This causes the outer teeth of the flexible wheel to mesh sequentially with the inner teeth of the rigid wheel housing 4-3, completing the harmonic speed reduction transmission with a transmission ratio of 50:1. This converts the high-speed, low-torque rotation output by the motor into extremely low-speed, high-torque rotation.

[0065] When the flexible wheel rotates, the outer cylinder 4-2 rotates synchronously, and the cam groove 4-2-1 on its side wall rotates synchronously, forcing the transmission pin 5-1 embedded in the groove to produce axial displacement, which in turn drives the telescopic inner cylinder 5-2 to make axial linear movement along the guide structure of the base 1, so as to achieve precise focusing of the lens.

[0066] Once the focus is achieved, the motor completes electromagnetic braking and locking, resulting in low standby power consumption. When the motor receives a focus command to start, it outputs torque to unlock and drive the transmission system.

[0067] The core performance indicators ultimately achieved in this embodiment are: the weight of the entire unit without the motor and lens is <130g, which is more than 60% lighter than the traditional steel module; focusing accuracy is ±10μm; transmission efficiency is ≥95%; it can work stably for a long time in the extreme environments of space vacuum and low temperature; the base is adapted to the standard installation interface of space payload to meet the requirements of engineering assembly; and it fully realizes the deep integration of lightweight, low power consumption, high precision, extreme environment adaptability and autonomous focusing capability, providing reliable key technical support for high-resolution space remote sensing imaging.

[0068] This invention is not limited to the embodiments described above. The above description of specific embodiments is intended to illustrate and explain the technical solutions of this invention. The specific embodiments described above are merely illustrative and not restrictive. Without departing from the spirit and scope of the claims, those skilled in the art can make many specific modifications based on the teachings of this invention, and these modifications all fall within the scope of protection of this invention.

Claims

1. A space optical focusing platform, characterized in that, The focusing platform includes: The base (1) serves as the mounting carrier; The motor drive assembly (2) is fixed to the base (1), and its power output axis is arranged perpendicular to the main optical axis of the focusing platform. The reversing transmission assembly (3) has its input end connected to the output shaft of the motor drive assembly (2), and its output end is a wave generator (3-3) set coaxially. The harmonic deceleration transmission assembly (4) includes a rigid wheel housing (4-3) fixed to the base (1) and a flexible wheel rotating outer cylinder (4-2), a thin-walled flexible bearing (4-1) sleeved on the wave generator (3-3), the outer wall of the flexible wheel rotating outer cylinder (4-2) having transmission teeth that mesh with the inner teeth of the rigid wheel housing (4-3), and the inner wall of the flexible wheel rotating outer cylinder (4-2) having a helical cam groove (4-2-1); and The cylindrical cam focusing assembly (5) includes a telescopic inner cylinder (5-2) and a transmission pin (5-1). The telescopic inner cylinder (5-2) is used to carry optical lenses. An axial guide structure is provided between the telescopic inner cylinder (5-2) and the base (1) to restrict the circumferential rotational freedom of the telescopic inner cylinder (5-2). One end of the transmission pin (5-1) is fixed to the telescopic inner cylinder (5-2), and the other end is embedded in the spiral cam groove (4-2-1).

2. The space optical focusing platform according to claim 1, characterized in that, The reversing transmission assembly (3) includes a motor bevel gear (3-1) and a wave generator bevel gear (3-2) that mesh with each other. The motor bevel gear (3-1) is fixed to the output shaft of the motor drive assembly (2). The wave generator bevel gear (3-2) is coaxially fixed with the wave generator (3-3). The wave generator (3-3) has an elliptical cam structure.

3. The space optical focusing platform according to claim 2, characterized in that, The motor bevel gear (3-1), the wave generator bevel gear (3-2), and the wave generator (3-3) are all made of polyetheretherketone (PEEK) material.

4. The space optical focusing platform according to claim 1, characterized in that, The flexible wheel rotating outer cylinder (4-2) is made of 7075-T6 aluminum alloy, and the flexible wheel rotating outer cylinder (4-2) is provided with a part of the working side cylinder wall for setting the spiral cam slide groove (4-2-1).

5. The space optical focusing platform according to claim 1, characterized in that, The base (1) is a ring structure, including an inner ring (1-1), an outer ring (1-2) and protrusions (1-4). The inner ring (1-1) and the outer ring (1-2) are connected by several connecting rods (1-3). The inner wall of the inner ring (1-1) is provided with several protrusions (1-4) at equal intervals. A vertical groove is formed between two protrusions (1-4). The outer wall of the telescopic inner cylinder (5-2) is provided with a slider (5-2-1) that cooperates with the vertical groove. The vertical groove and the slider (5-2-1) together constitute an axial guide structure, and the material has self-lubricating properties.

6. The space optical focusing platform according to claim 1, characterized in that, Both the base (1) and the telescopic inner cylinder (5-2) are made of modified polypropylene (PP) copolymer.

7. The space optical focusing platform according to claim 1, characterized in that, The outer shell of the rigid wheel (4-3) is made of nylon PA, and the surface of the outer shell of the rigid wheel (4-3) is provided with a honeycomb hollow weight reduction structure.

8. The space optical focusing platform according to claim 1, characterized in that, The motor drive assembly (2) includes a servo motor, which has an absolute magnetic encoder built in.

9. The space optical focusing platform according to claim 1, characterized in that, The outer periphery of the flexible wheel rotating outer cylinder (4-2) is rotatably supported and connected to the rigid wheel outer shell (4-3) by a thin-walled deep groove ball bearing (6).

10. A method for operating the space optical focusing platform according to any one of claims 1-9, characterized in that, include: When the control system issues a focusing command, the servo motor of the motor drive component (2) starts to rotate, driving the motor bevel gear (3-1) to rotate synchronously, and transmitting power to the wave generator bevel gear (3-2) through meshing transmission, completing 90° vertical power reversal and initial deceleration; The wave generator bevel gear (3-2) drives the coaxially fixed wave generator (3-3) to rotate. The wave generator (3-3) forces the flexible wheel rotating outer cylinder (4-2) to undergo periodic elastic deformation through the thin-walled flexible bearing (4-1), so that the outer teeth of the flexible wheel rotating outer cylinder (4-2) mesh with the inner teeth of the rigid wheel outer shell (4-3) in sequence, completing the harmonic speed reduction transmission and converting the high-speed, low-torque rotation output by the motor into low-speed, high-torque rotation. When the flexible wheel rotates the outer cylinder (4-2), the cam groove (4-2-1) on its cylinder wall rotates synchronously, forcing the transmission pin (5-1) embedded in the cam groove (4-2-1) to produce axial displacement, thereby driving the telescopic inner cylinder (5-2) to make axial linear motion along the axial guide structure of the base 1, so as to realize the focusing of the lens.

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