Frequency tunable solid-state damping vibration absorber for space environments

Abstract

A frequency-adjustable solid-state damping vibration absorber for space environment is constituted by a structural frame, a spring, a spring pressing block, a vibrator, a damping sheet and a shaft sleeve. The principle is that under forced vibration consistent with the frequency of the vibration absorber, the vibrator reciprocates to drive the damping sheet to move, and the internal damping of the damping sheet and the friction between the damping sheets are used to convert mechanical energy into heat energy, so as to quickly attenuate the vibration energy / amplitude. The core idea is based on the factors of vibration, vacuum, radiation and the like existing in the space environment, materials meeting the requirements of the space environment and anti-cold welding design are adopted, the system frequency is adjusted by adjusting the mass (m) and support stiffness (k) of the vibrator, and the damping size (c) is adjusted by the number of the rubber damping sheets, so as to adapt to different use requirements. The vibration caused by self-excitation or forced excitation can be quickly attenuated by installing the vibration absorber on the product in the space environment, and the vibration absorber has the advantages of compact structure, flexible installation, convenient adjustment, high environmental adaptability and reliability.

Description

Technical Field

[0001] This invention relates to the field of vibration suppression technology for space products, and in particular to a frequency-adjustable solid-state damping vibration absorber for space environments, which is mainly used to rapidly attenuate vibrations of space products (especially precision optomechanical equipment and high-precision pointing mechanisms) caused by self-excitation or forced excitation. Background Technology

[0002] Space products, especially precision optomechanical equipment and high-precision pointing and tracking mechanisms, are widely used in laser communication, lidar, and Earth observation. Precision optical instruments undergo meticulous assembly, adjustment, and testing during manufacturing to meet micrometer-level positional tolerances. The mechanical vibration environment experienced by space products during the active phase of launch poses a significant challenge to the performance of optical instruments, making vibration suppression essential. High-precision pointing and tracking mechanisms are commonly used in laser communication and laser weaponry, targeting distant objects ranging from hundreds to tens of thousands of kilometers, requiring pointing mechanisms with precision at the microradian level. In laser communication and laser weaponry, the load on high-precision pointing and tracking mechanisms is typically an optical antenna or a large-aperture mirror, characterized by high stiffness and low self-damping. Especially when using piezoelectric motors as the drive mechanism, the system's fast response and high frequency lead to self-excited vibrations during pointing and tracking due to frequent turning and starting / stopping. These vibrations, occurring near the target position, affect the tracking and aiming performance, necessitating a clear requirement for vibration suppression.

[0003] Space products, due to their demanding mechanical vibration conditions, high vacuum, cosmic radiation, and high reliability, place stringent requirements on material selection, lubrication, sealing methods, radiation resistance design, and miniaturization / lightweight design. Conventional liquid and gas dampers are difficult to use under high vacuum conditions, and reliable sealing requires significant resource consumption. Currently, vibration reduction and absorption in space products mainly focus on the entire satellite or spacecraft. The vibration isolation platform also serves as the mounting support structure, resulting in a strong coupling with the overall structural design, making it difficult to target vibration reduction and absorption for sensitive local areas and frequencies. The damping materials used are mostly one-piece metal or rubber blocks, which are not conducive to flexible adjustment of damping magnitude and do not utilize multi-contact friction to increase energy dissipation. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a frequency-adjustable solid-state damping vibration absorber for space environments. This damper has a simple and compact structure, high reliability, and adopts a cold-welding-resistant and radiation-resistant design. It is flexible in installation and use, and can attenuate the vibrations of space products (especially precision optomechanical equipment and high-precision pointing mechanisms) caused by self-excitation or forced excitation without changing the overall configuration of the original product. This improves the reliability and stability of space products, avoids development risks, shortens the development cycle, and reduces development costs.

[0005] The technical concept of this invention is as follows: Precision optomechanical equipment and high-precision pointing mechanisms on space products typically possess high stiffness and low damping characteristics. Under forced or self-excited vibration, the amplitude of the vibration response is large and the decay time is long, posing a significant challenge to the product's safety and performance. This invention employs a combination of a mass block, an oscillator, a spring, and a rubber damping sheet. The resonant frequency of the vibration absorber is adjusted to match the frequency at which the product requires vibration reduction. When the space product vibrates, it induces resonance in the vibration absorber. The oscillator reciprocates within the absorber, causing the rubber damping sheet connected to the oscillator to deform and rub against each other, converting mechanical energy into heat energy. This rapidly attenuates the vibration energy, suppresses the vibration amplitude of the space product, and improves execution accuracy.

[0006] The invention comprises a structural frame, a spring, a spring clamping block, an oscillator (with adjustable mass), rubber damping sheets, and a bushing. Its working principle is as follows: under forced vibration at the same frequency as the vibration absorber, the oscillator reciprocates, driving the connected rubber damping sheets to move. The internal damping of the rubber damping sheets and the friction between them convert mechanical energy into heat energy, achieving rapid attenuation of vibration energy / amplitude.

[0007] This invention addresses the vibration, vacuum, and radiation factors present in the space environment. The vibration absorber is made of solid materials that meet the requirements of space environment use, eliminating risks such as leakage and foreign matter. The friction-reducing bushing is made of polyimide material with good self-lubricating effect, radiation resistance, and structural strength. Furthermore, the friction pair composed of polyimide and 304 stainless steel effectively prevents cold welding in space. The frequency of the entire vibration system is adjusted by regulating the mass (m) and support stiffness (k) of the oscillator, and the damping magnitude (c) is adjusted by the number of rubber damping sheets to adapt to different usage requirements.

[0008] This invention designs a rectangular mounting frame that can be flexibly adjusted to a fully enclosed or semi-open configuration depending on the usage scenario. The frame is made of aluminum alloy, which has good thermal conductivity and can be combined with different surface thermal control treatment states to achieve more flexible thermal control design.

[0009] This invention designs a cross-shaped spring oscillator that symmetrically connects the spring and damping plate together and can move along the axial direction.

[0010] This invention designs an adjustable spring oscillator mass and spring stiffness, which can adjust the resonant frequency of the damper.

[0011] This invention designs a motion friction pair of polyimide and 304 stainless steel, which can achieve solid self-lubrication while avoiding the spatial cold welding effect.

[0012] This invention designs a thin-sheet stacked solid damper, which uses stacked rubber damping sheets of 0.5 to 1 mm. This reduces the stiffness of the damping sheets, increases the amount of deformation, generates multi-contact surface friction energy dissipation, and improves the vibration absorption effect; it also allows for flexible adjustment of the required damping coefficient.

[0013] This invention designs a centrally slotted rubber damping sheet. By slotting a rectangular rubber damping sheet, the stiffness in the vibration direction is reduced, and the deformation in the vibration direction is achieved.

[0014] This invention features a labyrinthine vent design that can quickly balance air pressure changes during ground testing, rapidly release air during launch, and prevent foreign matter from entering.

[0015] The enclosed radiation-resistant frame provides mounting interfaces, structural support, and radiation shielding for internal components. A flat, cross-shaped oscillator is mounted at the center of the product, with its slender ends passing through anti-cold-welded bushings mounted on the frame. Two symmetrical springs, coaxial with the oscillator shafts and mounted on their outer sides, provide elastic support to the oscillator through a clamping structure on the bushings, maintaining its centered initial position. A mass block for fine-tuning the resonant frequency can be mounted on the oscillator. The nitrile rubber damping sheet has three mounting holes: the two end holes connect to the structural frame (fixed end); the middle hole connects to the oscillator (moving end). Damping sheets are typically arranged in groups of two, one set at the top and one set at the bottom, and one set to the left and right. The number of damping sheets can be adjusted to increase or decrease damping as needed. Each damping sheet has regularly arranged through-grooves to reduce rigidity and increase deformation. The friction between the two sheets during vibration also accelerates energy dissipation. The anti-cold welding bushing has a two-layer structure. The outer layer is made of aluminum alloy, providing structural support, while the inner layer is a polyimide bushing that contacts the oscillator shaft with a clearance fit. The polyimide bushing reduces the coefficient of contact friction and is an excellent self-lubricating material. Furthermore, the combination of polyimide and 304 stainless steel (oscillator material) in the friction pair prevents cold welding effects in high vacuum environments. A labyrinth venting structure is symmetrically distributed on both sides of the frame, allowing for rapid equalization of the internal and external air pressures of the vibration absorber under normal pressure, without compromising radiation resistance or dustproof capabilities.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] 1) Based on factors such as vibration, vacuum, and radiation present in the space environment, the vibration absorber is made of solid materials that meet the requirements of the space environment. The moving parts adopt a cold-resistant welding design. The system frequency is adjusted by adjusting the mass (m) and support stiffness (k) of the oscillator, and the damping magnitude (c) is adjusted by the number of rubber damping sheets to adapt to different usage requirements.

[0018] 2) The entire structure is designed as a solid state, without any gaseous or liquid forms that are difficult to use in a space environment. At the same time, it is compact, lightweight, and has strong radiation resistance, and can be flexibly placed in the required location.

[0019] 3) It can be installed on products in the space environment to quickly attenuate product vibrations caused by self-excitation or forced excitation. It has the advantages of compact structure, flexible installation, easy adjustment, environmental adaptability and high reliability. Attached Figure Description

[0020] Figure 1 A schematic diagram of a frequency-adjustable solid-state damping vibration absorber for space environment provided by the present invention;

[0021] Figure 2 A cross-sectional schematic diagram of a frequency-adjustable solid-state damping vibration absorber for space environments provided by the present invention;

[0022] Figure 3 This is a schematic diagram of the labyrinth-type vent structure provided by the present invention.

[0023] Figure 4 This is a diagram illustrating the usage status of a frequency-adjustable solid-state damping vibration absorber for space environments according to the present invention.

[0024] In the figure: 1—frame; 2—adjusting sleeve; 3—cross-shaped vibrator; 4—mass adjustment plate; 5—spring; 6—damping plate; 7—crossbeam; 8—friction-reducing bushing; 9—cover plate; 10—labyrinth venting structure; 11—venting base; 12—venting cover plate; 13—this invention; 14—pitch axis system; 15—azimuth axis system; 16—base. Detailed Implementation

[0025] The present invention will be further described below with reference to embodiments and accompanying drawings, but this should not be construed as limiting the scope of protection of the present invention.

[0026] See Figure 1 , Figure 2 This is a schematic diagram of the structure of a frequency-adjustable solid-state damping vibration absorber for space environments according to the present invention. As shown in the figure, the invention includes: a frame 1; an adjusting sleeve 2; a cross-shaped oscillator 3; a mass adjusting plate 4; a spring 5; a damping plate 6; a crossbeam 7; a friction-reducing bushing 8; a cover plate 9; and a labyrinth venting structure 10. Their assembly relationship is as follows:

[0027] Frame 1 and crossbeam 7 form the structural foundation of the entire device, providing a base for the installation and fixation of other components. Anti-friction bushings 8 are installed on both sides of frame 1 and fixed with screws. Their inner holes provide radial constraint and support for the cross-shaped oscillator 3, releasing axial freedom. A spring 5 is installed on each side of the cross-shaped oscillator 3 along its axial direction. Supported by the springs 5, the cross-shaped oscillator 3 is stabilized in the middle position of the device when not in operation. Both sides of the cross-shaped oscillator 3 are connected to damping plates 6 via screws and nuts. The two ends of the damping plates 6 are connected to fixing holes on frame 1, and multiple plates can be stacked. Adjusting sleeve 2 is installed on the anti-friction bushing 8, with its end face used to support the springs 5. A mass adjustment plate 4 is installed at the center of mass of the cross-shaped oscillator 3 to adjust the resonant frequency of the system. Cover plates 9 are installed on frame 1, sealing the device and providing heat dissipation interfaces, supporting customized designs. Labyrinth venting structures 10 are installed on both sides of frame 1, symmetrically distributed. The labyrinth venting structure 10 consists of a venting base 11 and a venting cover plate 12, as shown... Figure 3 This forms a labyrinthine venting channel, which can effectively prevent foreign objects from entering without affecting vacuum venting.

[0028] After installation, the cross-shaped oscillator 3 can perform one-dimensional reciprocating motion along the axial direction inside the device, driving the damping plate to deform and rub, thereby realizing the conversion of mechanical energy into thermal energy and achieving the effect of vibration absorption.

[0029] The entire structure is designed as a solid state, eliminating the gaseous and liquid forms that are difficult to use in a space environment. It is also compact, lightweight, and highly resistant to radiation, and can be flexibly placed in the required location.

[0030] When using frequency-adjustable solid-state damping vibration absorbers for space environments, it is first necessary to test and determine the desired vibration absorption frequency. This can be obtained by combining the steady-state positive excitation method with FFT analysis of the residuals of motion control.

[0031] Based on the test and analysis results, solid-state damping vibration absorbers that have been frequency matched are arranged in the direction where vibration reduction is required. The installation position is placed at the location with the maximum response, and the axial direction of the vibration absorber oscillator is parallel to the vibration direction.

[0032] Figure 4 This paper demonstrates an application scenario for a frequency-adjustable solid-state damping vibration absorber for space environments, which can be placed at the far end of the pitch axis system to suppress the self-excited vibration effect of the structure caused by the high-frequency reciprocating motion of the pitch axis.

[0033] This invention provides a frequency-adjustable solid-state damping vibration absorber for space environments. The damper has a simple and compact structure, high reliability, and adopts a cold-welding-resistant and radiation-resistant design. It is flexible in installation and use. Without changing the overall configuration of the original product, the vibration absorber can be added to attenuate the vibration of space products (especially precision optomechanical equipment and high-precision pointing mechanisms) caused by self-excitation or forced excitation, thereby improving the reliability and stability of space products, avoiding development risks, shortening the development cycle, and reducing development costs.

Claims

1. A frequency-tunable solid-state damping vibration absorber for space environments, characterized by, include: Frame, adjusting sleeve, cross-shaped oscillator, mass adjusting plate, spring, damping plate and friction-reducing bushing; The friction-reducing bushing is nested on both sides of the frame. Springs are respectively fitted on both sides of the cross-shaped oscillator along the axial direction. Supported by the springs, the cross-shaped oscillator is stabilized in the middle position of the device when not in operation. Both ends of the cross-shaped oscillator extend into the central hole of the friction-reducing bushing, providing radial constraint and support while releasing axial freedom. The cross-shaped oscillator is connected to a damping plate, both ends of which are fixed to the frame. The adjusting sleeve is installed on the friction-reducing bushing, its end face used to support the springs. The mass adjusting plate is installed at the center of mass of the cross-shaped oscillator to adjust the resonant frequency of the system. The cross-shaped oscillator performs one-dimensional reciprocating motion along the axial direction inside the frame. Friction between the cross-shaped oscillator and the friction-reducing bushing causes the damping plate to deform, thereby converting mechanical energy into thermal energy and achieving vibration absorption.

2. The frequency-adjustable solid-state damping vibration absorber for space environments according to claim 1, characterized in that, It also includes a labyrinth venting structure symmetrically installed on both sides of the frame. The labyrinth venting structure consists of a venting base and a venting cover, forming a labyrinth-style venting channel to prevent foreign objects from entering, while not affecting vacuum venting.

3. The frequency-adjustable solid-state damping vibration absorber for space environments according to claim 1, characterized in that, It also includes a cover plate, which is installed on the upper and lower surfaces of the frame to seal the device and provide a heat dissipation interface.

4. The frequency-adjustable solid-state damping vibration absorber for space environments according to claim 1, characterized in that, It also includes a labyrinth venting structure, which consists of a venting base and a venting cover, effectively preventing foreign objects from entering while not affecting vacuum venting.

5. The frequency-adjustable solid-state damping vibration absorber for space environments according to claim 1, characterized in that, The inner surface of the vibration absorber is made of aluminum alloy with black anodizing treatment, while the outer surface can be painted white, anodized black, or left untreated depending on the heat dissipation requirements.

6. The frequency-adjustable solid-state damping vibration absorber for space environments according to claim 1, characterized in that, The damping sheet is a rubber damping sheet, and multiple sheets are used in a stacked manner to reduce the stiffness of the damping sheet and increase the amount of deformation. At the same time, the friction between them can accelerate energy dissipation.

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