Infrared focal plane refrigeration machine micro-vibration isolation and vibration absorption device
By designing a vibration isolation and absorption device on the infrared focal plane refrigerator, micro-vibrations are isolated and absorbed, thus solving the problem of the refrigerator's vibration affecting imaging. This achieves efficient and reliable vibration control and reduces imaging blur.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- BEIJING RES INST OF SPATIAL MECHANICAL & ELECTRICAL TECH
- Filing Date
- 2023-11-27
- Publication Date
- 2026-06-23
AI Technical Summary
Existing technologies cannot effectively reduce the impact of micro-vibrations on the camera's focal plane, both from the infrared refrigerator itself and those transmitted through the satellite module, resulting in blurred images.
Design a micro-vibration isolation and vibration absorption device for an infrared focal plane refrigerator, including a focal plane vibration isolation structure, a compressor vibration isolation structure, a vibration absorber and a limiting structure. Through the combination of leaf springs and shims, vibration is isolated and absorbed, and displacement is limited by the limiting structure.
It effectively reduces the vibration transmitted from the cooling unit to the focal plane, reduces the impact on imaging, improves imaging quality, and the device is highly reliable and low in cost.
Smart Images
Figure CN117704002B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of space optical remote sensor technology, and relates to a micro-vibration isolation and vibration absorption device for an infrared focal plane refrigerator of a space optical remote sensor. Background Technology
[0002] Space infrared cameras are precision optical remote sensing systems used for Earth resource exploration and space astronomical observation. The space refrigerator is an essential cooling device for focal plane imaging. As a moving mechanism, the refrigerator generates small-scale vibrations during operation due to momentum imbalances in moving parts such as pistons and the alternating flow of the working fluid. When these vibrations are transmitted to the camera's focal plane or mounting location, they cause the camera as a whole or in parts to deviate from its normal range, resulting in blurred images. With the increasing resolution of cameras, vibration reduction and suppression technologies are urgently needed to reduce the impact of micro-vibrations transmitted from the refrigerator to the focal plane. Internationally, vibration reduction technology for the refrigerator is considered a key technology affecting its application.
[0003] With the development of refrigeration machines, vibration isolation and reduction technology has been widely used. Publication number CN207867998U discloses a device for reducing the vibration of refrigeration machines, but this device only uses rubber balls to isolate its own vibration and cannot handle the micro-vibrations transmitted to the focal surface. Summary of the Invention
[0004] The technical problem solved by this invention is to overcome the shortcomings of the prior art and propose a micro-vibration isolation and vibration absorption device for an infrared focal plane refrigerator, which solves the problem of image disturbance caused by excessive micro-vibrations of the infrared refrigerator itself and those transmitted through the satellite compartment during operation, and has the ability to simultaneously isolate the transmission path and reduce the vibration transmitted from the refrigerator to the focal plane.
[0005] The solution of the present invention is:
[0006] A micro-vibration isolation and vibration absorption device for an infrared focal plane refrigerator includes a focal plane isolation structure, a focal plane limiting structure, a lower base, an upper base, a focal plane vibration absorber, a compressor vibration absorber, a compressor vibration isolation structure, a vibration absorber bracket, a compressor bracket, and a compressor limiting structure.
[0007] Four sets of focal plane vibration isolation structures are installed between the lower base and the upper base. The lower base is installed on the camera body and the upper base is installed on the infrared focal plane. The focal plane vibration absorber is installed at the cold finger end of the infrared focal plane. The focal plane limiting structure is installed between the lower base and the upper base to limit the displacement of the upper base.
[0008] Four sets of compressor vibration isolation structures are installed between the compressor bracket and the compressor. The compressor bracket is installed on the satellite compartment panel, the vibration absorber bracket is installed on the axial end face of the compressor, and the compressor vibration absorber is installed on the vibration absorber bracket by threads. The compressor limiting structure is installed between the compressor bracket and the compressor to limit the displacement of the compressor.
[0009] The coke surface vibration isolation structure and the compressor vibration isolation structure are the same, both including an upper connecting block, a lower connecting block, a leaf spring, and a washer; the leaf spring is placed on the washer, and the overall structure of the leaf spring and the washer is fixed between the upper connecting block and the lower connecting block; after installation, the leaf spring of the coke surface vibration isolation structure is located at the center of mass of the coke surface assembly, and the leaf spring of the compressor vibration isolation structure is located at the center of mass of the compressor.
[0010] Preferably, in the coke surface vibration isolation structure and the compressor vibration isolation structure, the overall structure of the leaf spring and the washer is fixed to the lower connecting block by the edge screw, and the leaf spring is connected to the upper connecting block by the middle screw.
[0011] Preferably, the leaf spring is made of stainless steel and is flexible through a cross-shaped hollow structure.
[0012] Preferably, the compressor vibration absorber and the coke surface vibration absorber have the same structure and configuration, and the difference in modal frequency between the compressor vibration absorber and the coke surface vibration absorber is controlled within 0.05Hz.
[0013] Preferably, the compressor vibration absorber and the coke surface vibration absorber have the same structure, both including a mounting shaft, vibration-absorbing leaf springs and a housing; the mounting shaft is a threaded shaft used to mount the vibration absorber; the vibration-absorbing leaf springs are helical in shape, with the inner rings of the four vibration-absorbing leaf springs mounted on the mounting shaft and the outer rings mounted on the housing.
[0014] Preferably, the focal plane limiting structure includes two first limiting blocks and two second limiting blocks. One first limiting block is installed on each side of the upper seat. The contact point between the first limiting block and the upper seat is designed as an L-shaped structure to limit the displacement of the upper seat moving towards the lower base. Two grooves symmetrically arranged along the center of the upper seat are opened on the lower surface of the upper seat. The grooves are used to install the second limiting blocks. The contact point between the second limiting blocks and the upper seat is designed as an L-shaped structure to limit the displacement of the upper seat moving away from the lower base.
[0015] Preferably, there is a gap of 1mm between the first limiting block and the second limiting block and the upper seat.
[0016] Preferably, the compressor vibration isolation structure includes two third limiting blocks and two fourth limiting blocks. One third limiting block is installed on each side of the compressor. The contact area between the third limiting block and the compressor is designed as an L-shaped structure to limit the displacement of the compressor moving towards the compressor support. Two grooves symmetrically arranged along the center of the compressor are opened on the lower surface of the compressor housing. The grooves are used to install the fourth limiting blocks. The contact area between the fourth limiting blocks and the compressor is designed as an L-shaped structure to limit the displacement of the compressor moving away from the compressor support.
[0017] Preferably, there is a gap of 1 mm between the third and fourth limiting blocks and the compressor.
[0018] Preferably, the upper seat, lower base, and compressor bracket are all made of titanium alloy.
[0019] The advantages of this invention compared to the prior art are:
[0020] (1) The present invention provides a micro-vibration isolation and vibration absorption device for an infrared focal plane refrigerator. Vibration absorbers are installed at the cold finger and compressor end face of the focal plane refrigerator. This device can effectively absorb the micro-vibration sources at the two locations of the refrigerator, greatly reducing the micro-vibration output of the refrigerator from the source and reducing the impact of the refrigerator on imaging.
[0021] (2) The vibration isolation and absorption device used in this invention is a passive vibration isolation and absorption device. Compared with the complex active vibration isolation and absorption device, it has good reliability, is easy to process and implement, and has low cost.
[0022] (3) The focal plane vibration isolation device used in this invention can effectively isolate the vibration transmitted from the outside to the focal plane. By appropriately adjusting the leaf spring parameters, the transmission rate can be reduced to 10%.
[0023] (4) The compressor vibration isolation device used in this invention can effectively isolate the vibration transmitted from the compressor to the satellite. By appropriately adjusting the leaf spring parameters, the transmission rate can be reduced to 10%, thus preventing the compressor from affecting itself or other satellite equipment through the satellite cabin.
[0024] (5) The limiting structure used in this invention is simple and reliable, and can effectively limit the displacement of the focal plane and the compressor, thus avoiding damage to the focal plane and the compressor from large-scale vibrations during launch. Attached Figure Description
[0025] Figure 1 General drawing of the micro-vibration isolation and vibration absorption device for the infrared focal plane refrigerator;
[0026] Figure 2 This is a schematic diagram of vibration isolation at the focal plane.
[0027] Figure 3 Detailed composition diagram of the vibration isolation structure;
[0028] Figure 4 This is a schematic diagram of a leaf spring;
[0029] Figure 5 This is a schematic diagram of the vibration absorber structure. Detailed Implementation
[0030] The present invention will be further described below with reference to the embodiments.
[0031] This invention solves the problem of image disturbance caused by excessive micro-vibrations during the operation of the infrared refrigerator itself and those transmitted through the satellite compartment. At the same time, it utilizes a limiting structure to reduce the vibration response of the focal plane and the refrigerator when passing through the transmission section.
[0032] like Figure 1 As shown, the present invention provides a micro-vibration isolation and vibration absorption device for an infrared focal plane refrigerator, comprising 4 sets of focal plane isolation structures, a focal plane limiting structure, a lower base 1, an upper base 3, a focal plane vibration absorber, a compressor isolation structure, a compressor vibration absorber, a vibration absorber bracket 10, a compressor bracket 7, and a compressor limiting structure.
[0033] The lower base 1 is mounted to the camera body using four M6 screws. Four sets of focal plane isolation structures are mounted between the lower base 1 and the upper base 3 using four M5 screws. The upper base 3 is connected to the focal plane isolation structures using four M5 screws and to the infrared focal plane using six M3 screws. The lower base 1, made of titanium alloy, is mounted on the camera body and provides the mounting interface for the isolation and limiting structures. The upper base 3, also made of titanium alloy, is mounted on the infrared focal plane and provides the mounting interface for the isolation and limiting structures.
[0034] The coke surface vibration isolation structure is exactly the same as the compressor vibration isolation structure, and is referred to as vibration isolation structure 2. Figure 3 The detailed structure of the vibration isolation structure is given. It includes an upper connecting block 21, a lower connecting block 24, a leaf spring 22, and a washer 23. The leaf spring 22 and washer 23 are mounted on the lower connecting block 24 using four M2.5 screws along the edge. The leaf spring 22 is connected to the upper connecting block 21 using an M6 screw in the center. The shape of the leaf spring is as follows... Figure 4 As shown, it is a cross-shaped pattern, and the groove width is obtained through design optimization. It is made of hollowed-out stainless steel material to form flexibility.
[0035] The leaf spring of the focal plane vibration isolation structure is located precisely at the center of mass of the focal plane assembly, providing elasticity for the entire vibration isolation assembly and achieving the purpose of isolating the main body from the micro-vibrations of the infrared focal plane.
[0036] A focal plane limiting structure is installed between the lower base and the upper base. It includes two first limiting blocks 5 and two second limiting blocks 4. The gap between each limiting block and the focal plane is 1mm, limiting excessive focal plane displacement caused by the flexibility introduced by the vibration isolation structure during the mechanical launch section. One first limiting block 5 is installed on each side of the upper base 3. The contact point between the first limiting block 5 and the upper base is designed with an L-shape to limit the displacement of the upper base 3 towards the lower base. Two grooves symmetrically arranged along the center of the upper base are formed on the lower surface of the upper base 3. These grooves are used to install the second limiting blocks 4. The contact point between the second limiting blocks 4 and the upper base is designed with an L-shape to limit the displacement of the upper base away from the lower base.
[0037] Figure 2A detailed schematic diagram of the infrared focal plane vibration isolation section is provided. The first limiting block 5 is mounted on the lower base 1 with two M3 screws, one on each side symmetrically. The gap between the first limiting block 5 and the upper base 3 is 1mm to achieve the limiting purpose. The second limiting block 4 is mounted on the lower base 1 with three M3 screws, one on each side symmetrically.
[0038] The focal plane vibration absorber is installed at the cold finger end of the infrared focal plane. The weight ratio of the focal plane vibration absorber to the infrared focal plane is 1:8 to achieve a balance between vibration absorption effect and weight.
[0039] The compressor bracket 7 is the support component for the compressor, mounted on the satellite compartment panel with four M6 screws. Made of titanium alloy, the compressor bracket 7 is installed between the satellite compartment panel and the compressor vibration isolation mechanism to support the compressor. Four sets of compressor vibration isolation structures are mounted on the compressor bracket 7 at one end and on the compressor body at the other end with four M5 screws. Their leaf springs are positioned precisely at the compressor's center of gravity, providing elasticity to the entire vibration isolation assembly and effectively isolating the compressor from the transmission path of vibrations transmitted through the satellite compartment panel.
[0040] The compressor limiting structure is installed between the compressor bracket and the compressor, including two third limiting blocks 8 and two fourth limiting blocks 9. One third limiting block 8 is installed on each side of the compressor. The contact area between the third limiting block 8 and the compressor is designed with an L-shape to limit the displacement of the compressor moving towards the compressor bracket 7. Two grooves symmetrically arranged around the center of the compressor are formed on the lower surface of the compressor housing. These grooves are used to install the fourth limiting blocks 9. The contact area between the fourth limiting blocks 9 and the compressor is designed with an L-shape to limit the displacement of the compressor moving away from the compressor bracket 7.
[0041] The third limiting block 8 and the fourth limiting block 9 are both mounted on the compressor bracket 7 with two M3 screws. The gap between the limiting blocks 8 and 9 and the compressor is 1mm, which limits the excessive compressor displacement caused by the flexibility introduced by the vibration isolation structure when passing through the mechanical launch section. The vibration absorber bracket 10 is mounted on the axial end face of the compressor with three M6 screws, providing a mounting interface for the compressor vibration absorber. The compressor vibration absorber is threaded onto the vibration absorber bracket 10.
[0042] The coke surface vibration absorber, installed on the cold finger of the refrigeration unit, is used to absorb the micro-vibrations of the cold finger. The compressor vibration absorber, installed on the vibration absorber bracket, is used to absorb the micro-vibrations of the compressor. The compressor vibration absorber and the coke surface vibration absorber have the same configuration, and the difference in vibration absorption mode frequency is controlled within 0.05Hz.
[0043] The structure and configuration of the coke surface vibration absorber and the compressor vibration absorber are exactly the same, and it is referred to as vibration absorber 6. Figure 5The detailed structure of the vibration absorber 6 is shown. It includes a mounting shaft 61, four vibration-absorbing leaf springs 63, and a housing 62. The mounting shaft 61 is an M16 threaded shaft used for mounting the vibration absorber. The four vibration-absorbing leaf springs 63 are helical; the inner ring is mounted to the mounting shaft 61 with six M4 screws, and the outer ring is mounted to the housing 62 with six M5 screws. According to the vibration absorption principle, when the natural frequency of the vibration absorber is the same as that of the vibration source, the vibration will be transferred to the vibration absorber. The operating frequency of the refrigerator is 50Hz, and the frequency of the entire vibration absorber is designed to be 50±0.05Hz to achieve the best vibration absorption effect.
[0044] In this invention, the stiffness of the leaf spring 22 is determined by the designed frequency. According to the vibration isolation principle, the frequency of the leaf spring should be 2 to 3 times less than the frequency being isolated to achieve a vibration isolation effect. The operating frequency of the refrigeration unit is 50Hz, so the vibration isolation frequency of the leaf spring should be less than 15Hz. According to the formula...
[0045]
[0046] K = 4π 2 F 2 M
[0047] Where F is the vibration isolation frequency, which is taken as 15Hz here, and M is the mass of the vibration isolation object, which is taken as the focal mass here. Based on this, the stiffness K of leaf spring 22 can be designed.
[0048] In this invention, each limiting block has a 1mm gap from the infrared focal plane and the compressor to achieve the purpose of limiting movement. The vibration-absorbing leaf spring of the vibration absorber has a helical shape and a natural frequency of 50±0.05Hz.
[0049] The contents not described in detail in this specification are common knowledge to those skilled in the art.
Claims
1. A micro-vibration isolation and vibration absorption device for an infrared focal plane refrigerator, characterized in that: The focus surface vibration isolation structure, the focus surface limiting structure, the lower base (1), the upper seat (3), the focus surface absorber, the compressor absorber, the compressor vibration isolation structure, the absorber support (10), the compressor support (7), and the compressor limiting structure are comprised. 4 sets of focus surface vibration isolation structures are installed between the lower base (1) and the upper seat (3), the lower base (1) is installed on the camera main body, and the upper seat (3) is installed on the infrared focus surface; the focus surface absorber is installed on the infrared focus surface cold finger end head; the focus surface limiting structure is installed between the lower base (1) and the upper seat (3), and the displacement of the upper seat (3) is limited. 4 sets of compressor vibration isolation structures are installed between the compressor support (7) and the compressor, the compressor support (7) is installed on the satellite cabin plate, the absorber support (10) is installed on the compressor axial end face, and the compressor absorber is installed on the absorber support through threads; the compressor limiting structure is installed between the compressor support and the compressor, and the displacement of the compressor is limited. The focus surface vibration isolation structure and the compressor vibration isolation structure are the same, and each comprises an upper connecting block, a lower connecting block, a leaf spring, and a gasket; the leaf spring is arranged on the gasket, and the overall structure of the leaf spring and the gasket is fixed between the upper connecting block and the lower connecting block. In the focus surface vibration isolation structure and the compressor vibration isolation structure, the overall structure of the leaf spring and the gasket is fixed on the lower connecting block through edge screws, and the leaf spring is connected to the upper connecting block through middle screws; the leaf spring is a cross-shaped hollow structure. The compressor absorber and the focus surface absorber have the same structure and configuration, and the modal frequency difference of the compressor absorber and the focus surface absorber is controlled within 0.05 Hz.
2. The micro-vibration isolation and vibration absorption device for an infrared focal plane refrigerating machine according to claim 1, characterized in that: The leaf spring is made of stainless steel.
3. The micro-vibration isolation and vibration absorption device for an infrared focal plane refrigeration machine according to claim 1, characterized in that: The compressor absorber and the focus surface absorber have the same structure, and each comprises a mounting shaft, an absorber leaf spring, and a shell; the mounting shaft is a threaded shaft used for mounting the absorber; the absorber leaf spring has a spiral shape, four absorber leaf springs are arranged on the mounting shaft, and the outer circle is arranged on the shell.
4. The micro-vibration isolation and vibration absorption device for an infrared focal plane refrigerating machine according to claim 1, characterized in that: The focus surface limiting structure comprises two first limiting blocks and two second limiting blocks, one first limiting block is arranged on each side of the upper seat (3), the contact part between the first limiting block and the upper seat is designed as an L-shaped structure, and the first limiting block is used for limiting the displacement of the upper seat moving towards the lower base; two recesses are arranged on the lower surface of the upper seat (3) and are symmetrically arranged on the center of the upper seat, the recesses are used for mounting the second limiting blocks, the contact part between the second limiting blocks and the upper seat is designed as an L-shaped structure, and the second limiting blocks are used for limiting the displacement of the upper seat moving away from the lower base.
5. The micro-vibration isolation and vibration absorption device for an infrared focal plane refrigerating machine according to claim 4, characterized in that: There is a gap between the first limiting block, the second limiting block, and the upper seat, and the gap is 1 mm.
6. The micro-vibration isolation and vibration absorption device for an infrared focal plane refrigerating machine of claim 1, characterized in that: The compressor vibration isolation structure comprises two third limiting blocks and two fourth limiting blocks, one third limiting block is arranged on each side of the compressor, the contact part between the third limiting block and the compressor is designed as an L-shaped structure, and the third limiting block is used for limiting the displacement of the compressor moving towards the compressor support; The lower surface of the compressor shell is provided with two recesses symmetrically arranged on the center of the compressor, the recesses are used for mounting the fourth limiting blocks, the contact part between the fourth limiting blocks and the compressor is designed as an L-shaped structure, and the fourth limiting blocks are used for limiting the displacement of the compressor moving away from the compressor support.
7. The micro-vibration isolation and vibration absorption device for an infrared focal plane refrigerating machine according to claim 6, characterized in that: There is a gap between the third limiting block, the fourth limiting block, and the compressor, and the gap is 1 mm.
8. The micro-vibration isolation and vibration absorption device for an infrared focal plane refrigerating machine according to claim 1, characterized in that: The upper seat, the lower base and the compressor support are made of titanium alloy material.