阅读说明：本技术 一种适用于低温光学系统的单限位螺垫及其使用方法 (Single-limit screw pad suitable for low-temperature optical system and use method thereof ) 是由 武俊强 张兆会 孙剑 冯玉涛 韩斌 吴阳 畅晨光 李娟� 于 2021-08-31 设计创作，主要内容包括：本发明公开了一种适用于低温光学系统的单限位螺垫及其使用方法。该该单限位螺垫用于光学系统安装板和真空密闭箱底板的螺纹连接,具体使用过程为：在光学系统安装板的上表面以及光学系统安装板下表面和真空密闭箱底板的上表面之间均放置单限位螺垫；固定螺钉依次穿过光学系统安装板上方的单限位螺垫、光学系统安装板、光学系统安装板下方单限位螺垫后与真空密闭箱底板上连接,从而实现光学系统安装板与真空密闭箱底板的对接安装,从而根本上解决了低温下由于光学系统安装底板与真空密闭箱温度及材料不同造成光学系统安装底板变形,从而影响光学系统装调精度的问题,大大提升了光学系统的使用可靠性。(The invention discloses a single-limit screw pad suitable for a low-temperature optical system and a using method thereof. This single spacing spiral shell pad is used for the threaded connection of optical system mounting panel and vacuum seal box bottom plate, and specific use is: single limiting screw pads are respectively arranged on the upper surface of the optical system mounting plate, the lower surface of the optical system mounting plate and the upper surface of the vacuum closed box bottom plate; the fixing screw sequentially penetrates through the single limiting screw pad above the optical system mounting plate, the optical system mounting plate and the single limiting screw pad below the optical system mounting plate and then is connected with the vacuum closed box bottom plate, so that butt joint installation of the optical system mounting plate and the vacuum closed box bottom plate is achieved, the problem that the optical system mounting bottom plate is deformed due to the fact that the optical system mounting bottom plate and the vacuum closed box are different in temperature and material at low temperature, installation and adjustment accuracy of the optical system is affected is fundamentally solved, and use reliability of the optical system is greatly improved.)

1. A single-limiting screw pad suitable for a low-temperature optical system is characterized by comprising an upper annular cushion block, a lower annular cushion block, a ball retainer, a ball, an inner cylinder, an outer ring, an end cover and a spring;

the upper annular cushion block and the lower annular cushion block are arranged in parallel, and a ball retainer is arranged in the area between the upper annular cushion block and the lower annular cushion block;

the ball retainer is provided with at least one row of balls, and each ball is in point contact with the upper annular cushion block and the lower annular cushion block;

the inner cylinder is divided into a first cylinder section, a second cylinder section, a third cylinder section and a fourth cylinder section with sequentially increased outer diameters from top to bottom, an inner hole of the inner cylinder is divided into a first through hole and a second through hole from top to bottom, and the aperture of the first through hole is smaller than that of the second through hole;

a first radial gap is formed between the first cylinder section and the inner hole of the upper annular cushion block, and the first cylinder section extends out of the upper surface of the upper annular cushion block;

the second cylinder section is matched with the inner hole of the upper annular cushion block for a shaft hole to realize radial positioning;

the third cylinder section is matched with an inner hole of the ball retainer for a shaft hole to realize radial positioning;

the fourth cylinder section is matched with the inner hole of the lower annular cushion block for a shaft hole to realize radial positioning;

the end cover is coaxially arranged in an inner hole of the lower annular cushion block;

one end of the spring is in contact with a transition surface between the first through hole and the second through hole, and the other end of the spring is in contact with the upper end surface of the end cover and is used for providing axial pretightening force for the inner cylinder;

the outer ring is sleeved outside the upper annular cushion block, the ball retainer and the lower annular cushion block, and a second radial gap is formed between the outer ring and the outer circle surface of the upper annular cushion block;

a first bulge arranged along the radial direction is arranged on the inner wall of the lower end of the outer ring and is used for being connected with the lower annular cushion block;

and a second bulge arranged along the radial direction is arranged on the inner wall of the lower end of the outer ring and used for limiting the axial movement of the upper annular cushion block.

2. The single-limit screw pad suitable for the cryogenic optical system as claimed in claim 1, wherein the end cap is installed in the inner hole of the lower annular pad by means of screw connection.

3. The single-limit screw pad suitable for the cryogenic optical system according to claim 1 or 2, wherein the first protrusion is screwed with the lower annular pad.

4. The single limit screw pad for a cryogenic optical system according to claim 3, wherein the ball retainer has at least two rows of balls.

5. The use method of the single limit screw pad suitable for the cryogenic optical system according to claim 1, wherein: the screw thread is used for connecting the optical system mounting plate and the vacuum closed box bottom plate;

single limiting screw pads are arranged on the upper surface of the optical system mounting plate and at positions corresponding to the butt joint through holes, and between the lower surface of the optical system mounting plate and the upper surface of the vacuum closed box bottom plate and at positions corresponding to the butt joint threaded holes in the vacuum closed box bottom plate;

the fixing screws sequentially penetrate through the single limiting screw pad above the optical system mounting plate, the butt joint through hole of the optical system mounting plate and the single limiting screw pad below the optical system mounting plate and then are in threaded connection with the butt joint threaded holes in the bottom plate of the vacuum closed box, and therefore butt joint installation of the optical system mounting plate and the bottom plate of the vacuum closed box is achieved.

Technical Field

The invention relates to a screw pad used during the assembly of an optical system, in particular to a single-limit screw pad suitable for a low-temperature optical system and a use method thereof.

Background

In a low-temperature imaging optical system, the optical system is often required to be refrigerated at a low temperature, so that the detection capability of a target long-wave spectral signal is improved. The optical system is cooled by completely placing the optical system in a vacuum closed box, refrigerating the optical system installation bottom plate through a refrigerator and a cold chain, and finally refrigerating each component of the optical system to a low temperature through heat conduction of the optical system installation bottom plate and each component of the optical system. The optical system mounting base plate and the vacuum closed box body are generally fixedly connected by screws, and a heat insulation pad is additionally arranged in the middle to prevent heat loss.

Compare with the normal atmospheric temperature, optical system mounting plate under the low temperature can take place great shrink, and along with the continuous reduction of temperature, the shrinkage constantly increases, because the difference of vacuum seal box and optical system mounting plate temperature and material, the shrinkage is also different under its low temperature, and at this moment, optical system mounting plate will receive great assembly stress and non-design spacing to cause optical system mounting plate to warp, further will influence optical system's dress and transfer the precision.

In order to solve the problems, the method generally adopted at present adopts a flexible connection mode at the joint of the optical system installation bottom plate and the vacuum closed box body, but the mode only weakens the influence of rigid connection on an optical component to a certain extent and cannot thoroughly solve the problem of deformation of the optical system installation bottom plate at low temperature.

Disclosure of Invention

In order to solve the problem that the installation and adjustment precision of the optical system is influenced due to the fact that the optical system installation bottom plate is deformed due to different temperatures and materials of the optical system installation bottom plate and the vacuum closed box at low temperature, the invention provides a single-limiting screw pad suitable for a low-temperature optical system and a using method thereof, and the problem can be fundamentally solved.

The specific technical scheme of the invention is as follows:

a single-limiting screw pad suitable for a low-temperature optical system comprises an upper annular cushion block, a lower annular cushion block, a ball retainer, a ball, an inner cylinder, an outer ring, an end cover and a spring;

the upper annular cushion block and the lower annular cushion block are arranged in parallel, and a ball retainer is arranged in the area between the upper annular cushion block and the lower annular cushion block;

the ball retainer is provided with at least one row of balls, and each ball is in point contact with the upper annular cushion block and the lower annular cushion block;

the inner cylinder is divided into a first cylinder section, a second cylinder section, a third cylinder section and a fourth cylinder section with sequentially increased outer diameters from top to bottom, an inner hole of the inner cylinder is divided into a first through hole and a second through hole from top to bottom, and the aperture of the first through hole is smaller than that of the second through hole;

a first radial gap is formed between the first cylinder section and the inner hole of the upper annular cushion block, and the first cylinder section extends out of the upper surface of the upper annular cushion block;

the second cylinder section is matched with the inner hole of the upper annular cushion block for a shaft hole to realize radial positioning;

the third cylinder section is matched with an inner hole of the ball retainer for a shaft hole to realize radial positioning;

the fourth cylinder section is matched with the inner hole of the lower annular cushion block for a shaft hole to realize radial positioning;

the end cover is coaxially arranged in an inner hole of the lower annular cushion block;

one end of the spring is in contact with a transition surface between the first through hole and the second through hole, and the other end of the spring is in contact with the upper end surface of the end cover and is used for providing axial pretightening force for the inner cylinder;

the outer ring is sleeved outside the upper annular cushion block, the ball retainer and the lower annular cushion block, and a second radial gap is formed between the outer ring and the outer circle surface of the upper annular cushion block;

a first bulge arranged along the radial direction is arranged on the inner wall of the lower end of the outer ring and is used for being connected with the lower annular cushion block;

and a second bulge arranged along the radial direction is arranged on the inner wall of the lower end of the outer ring and used for limiting the axial movement of the upper annular cushion block.

Furthermore, the end cover is installed in the inner hole of the lower annular cushion block in a threaded connection mode.

Further, the first protrusion is in threaded connection with the lower annular cushion block.

Further, the ball retainer is provided with at least two rows of balls.

Meanwhile, the invention also provides a using method of the single-limit screw pad, the single-limit screw pad is used for threaded connection of the optical system mounting plate and the vacuum closed box bottom plate, and the specific using process is as follows:

single limiting screw pads are arranged on the upper surface of the optical system mounting plate and at positions corresponding to the butt joint through holes, and between the lower surface of the optical system mounting plate and the upper surface of the vacuum closed box bottom plate and at positions corresponding to the butt joint threaded holes in the vacuum closed box bottom plate;

the fixing screws sequentially penetrate through the single limiting screw pad above the optical system mounting plate, the butt joint through hole of the optical system mounting plate and the single limiting screw pad below the optical system mounting plate and then are in threaded connection with the butt joint threaded holes in the bottom plate of the vacuum closed box, and therefore butt joint installation of the optical system mounting plate and the bottom plate of the vacuum closed box is achieved.

The invention has the beneficial effects that:

1. in the invention, single limiting screw pads are respectively arranged on the upper surface of the optical system mounting plate and the positions corresponding to the butt joint through holes, and between the lower surface of the optical system mounting plate and the upper surface of the vacuum closed box bottom plate and the positions corresponding to the butt joint threaded holes on the vacuum closed box bottom plate, under the pressure of the fixing bolt, the radial constraint of the upper and lower single limiting screw cushions is released, so that the optical system mounting plate is arranged on the bottom plate of the vacuum closed box in a floating way, because the first radial gap and the second radial gap can compensate the shrinkage deformation of the optical system installation bottom plate under the low-temperature environment, thereby fundamentally solving the problem that the optical system mounting bottom plate is deformed due to different temperatures and materials of the optical system mounting bottom plate and the vacuum closed box at low temperature, thereby influencing the installation and adjustment precision of the optical system and greatly improving the use reliability of the optical system.

2. The invention adopts the screw pad composed of the upper annular cushion block, the lower annular cushion block, the ball retainer, the ball, the inner cylinder, the outer ring, the end cover and the spring, has compact structure and small occupied space, and is still applicable to an optical system with strict space requirement.

3. The invention has strong universality and unchanged structural form, and can meet the use of different loads under various working conditions which can cause the connection piece to be changed after the sizes of the structural components are finely adjusted.

4. The assembly relation among all parts of the screw pad ensures that all parts are fixed in relative positions when the screw pad is in a non-working state, and the whole screw pad can be stored and used as a single component.

Drawings

Fig. 1 is a schematic structural view of a single limiting screw pad.

Fig. 2 is a top view of a cryogenic optical system.

FIG. 3 is a schematic view of a single limiting screw pad.

FIG. 4 is a schematic view of the working state of the single-position-limiting screw pad.

The reference numbers are as follows:

1-single limiting screw pad, 2-upper annular cushion block, 3-lower annular cushion block, 4-ball retainer, 5-ball, 6-inner cylinder, 61-first cylinder section, 62-second cylinder section, 63-third cylinder section, 64-fourth cylinder section, 65-first through hole, 66-second through hole 66, 7-outer ring, 71-first bulge, 72-second bulge, 8-end cover, 9-spring, 10-optical system installation bottom plate, 11-vacuum sealed box bottom plate, 13-vacuum sealed box and 14-fixing screw.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, specific embodiments accompanied with figures are described in detail below, and it is apparent that the described embodiments are a part of the embodiments of the present invention, not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without making creative efforts based on the embodiments of the present invention, shall fall within the protection scope of the present invention.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways than those specifically described and will be readily apparent to those of ordinary skill in the art without departing from the spirit of the present invention, and therefore the present invention is not limited to the specific embodiments disclosed below.

Meanwhile, in the description of the present invention, it should be noted that the terms "upper, lower, inner and outer" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation and operate, and thus, cannot be construed as limiting the present invention. Furthermore, the terms first, second, or third are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

The terms "mounted, connected and connected" in the present invention are to be understood broadly, unless otherwise explicitly specified or limited, for example: can be fixedly connected, detachably connected or integrally connected: they may be mechanically, electrically, or directly connected, or indirectly connected through intervening media, or may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The embodiment provides a specific structure of a single-limit screw pad suitable for a cryogenic optical system, and as shown in fig. 1, the screw pad comprises an upper annular pad 2, a lower annular pad 3, a ball retainer 4, balls 5, an inner cylinder 6, an outer ring 7, an end cover 8 and a spring 9;

when the single-limit screw pad 1 is in a non-working state, the upper annular cushion block 2 and the lower annular cushion block 3 are placed in parallel and keep a coaxial state, and a ball retainer 4 is arranged in an area between the upper annular cushion block 2 and the lower annular cushion block 3;

the ball retainer 4 is provided with at least one row of balls 5, and each ball 5 is in point contact with the upper annular cushion block 2 and the lower annular cushion block 3; the balls 5 can be arranged in a plurality of rows, and the number of the balls in the embodiment is 2 rows according to the actual use environment and the load condition;

the inner cylinder 6 is in a step-type structure through the surface of the excircle, and is respectively matched with the inner hole of the upper annular cushion block 2, the inner hole of the ball retainer 4 and the inner hole of the lower annular cushion block 3 to form shaft holes, so that the relative radial movement of the inner cylinder is limited; in this embodiment, the specific structure of the inner cylinder and the matching relationship with other parts are as follows:

the inner cylinder 6 is divided into a first cylinder section 61, a second cylinder section 62, a third cylinder section 63 and a fourth cylinder section 64 with sequentially increased outer diameters from top to bottom, an inner hole of the inner cylinder is divided into a first through hole 65 and a second through hole 66 from top to bottom, and the aperture of the first through hole 65 is smaller than that of the second through hole 66;

a first radial gap Q is formed between the first cylinder section 61 and the inner hole of the upper annular cushion block 2, and the first cylinder section 61 extends out of the upper surface of the upper annular cushion block 2;

the second cylinder section 62 is matched with the inner hole of the upper annular cushion block 3 for a shaft hole to realize radial positioning;

the third cylinder section 63 is matched with the inner hole of the ball retainer 4 for shaft hole to realize radial positioning;

the fourth cylinder section 64 is matched with the inner hole of the lower annular cushion block 3 for a shaft hole to realize radial positioning;

the outer ring 7 is connected with the lower annular cushion block 3, and the outer ring 7 can limit the axial movement of the upper annular cushion block 2; in this embodiment, the specific structure of the outer ring 7 and the matching relationship with other parts are as follows:

the outer ring 7 is sleeved outside the upper annular cushion block 2, the ball retainer 4 and the lower annular cushion block 3, and has a second radial gap P with the outer circular surface of the upper annular cushion block 2; the point to be emphasized here is: the first radial gap Q and the second radial gap P may have the same value, and specific values may be determined according to the deformation of the optical system at different test temperatures, but the conditions that must be satisfied are: the values of the first radial gap Q and the second radial gap P are both larger than the deformation.

A first bulge 71 arranged along the radial direction is arranged on the inner wall of the lower end of the outer ring 7 and is used for connecting with the lower annular cushion block 3; in order to facilitate assembly and disassembly, the first protrusion 71 and the lower annular cushion block 3 are in threaded connection in the embodiment;

a second bulge 72 arranged along the radial direction is arranged on the inner wall of the lower end of the outer ring 7 and used for limiting the axial movement of the upper annular cushion block 2;

the end cover 8 is coaxially arranged in an inner hole of the lower annular cushion block 2; one end of the spring 9 is in contact with a transition surface W between the first through hole 65 and the second through hole 66, and the other end of the spring is in contact with the upper end surface of the end cover 8, and is used for providing axial pre-tightening force for the inner cylinder 6. In order to facilitate assembly and disassembly, the end cover 8 and the inner hole of the lower annular cushion block 3 are connected through threads in the embodiment.

According to the above description of the structure of the single limit screw pad in the non-working state, the assembly relationship among the parts in the single limit screw pad 1 is reliable, and the single limit screw pad is in the stable state in the non-working state, and can be stored as an integral assembly without the problem of scattering of the parts.

Based on the above structural introduction of the single limit screw pad in the non-working state, a use method of the single limit screw pad is explained according to a specific use scene:

as shown in fig. 2, a plan view of a cryogenic optical system, an optical system 12 is disposed in a vacuum enclosure 13, in a conventional manner, an optical system mounting base plate 10 and a vacuum enclosure base plate 11 are fixedly connected by screws, and a heat insulating pad is disposed between the optical system mounting base plate 10 and the vacuum enclosure base plate 11;

in the embodiment, the single-limit screw pads 1 are respectively placed at the positions corresponding to the butt-joint through holes on the upper surface of the optical system mounting plate 10 and the positions corresponding to the butt-joint threaded holes on the vacuum sealing box bottom plate 11 between the lower surface of the optical system mounting plate 10 and the upper surface of the vacuum sealing box bottom plate 11, as shown in fig. 3, after the fixing screws 14 are screwed down, the inner cylinders 6 in the upper and lower single-limit screw pads 1 are pressed down, the radial limit of the inner cylinder 6 on the upper annular cushion block 2 and the ball retainer 4 is released, and the upper annular cushion block 2 and the lower annular cushion block 3 can move relatively in the radial direction.

As shown in fig. 4, in the low-temperature operating state of the optical system, the optical system mounting base plate 10 contracts at low temperature and radially displaces relative to the vacuum-tight box base plate 11, and if the displacement is a (the displacement is actually the shrinkage deformation of the optical system mounting base plate 10), the upper annular pad 2 and the lower annular pad 3 in the single-limit screw gasket 1 also move relative to each other by a distance a. Because the ball 5 is designed between the upper annular cushion block 2 and the lower annular cushion block 3, the relative movement between the upper annular cushion block 2 and the lower annular cushion block 3 is resistance-free movement. Because the optical system bottom plate 10 and the vacuum sealing box bottom plate 11 are fixed by the fixing screws 12 in the vertical direction, relative movement cannot occur in the vertical direction.

After the single-limit screw pad 1 is added, under the low-temperature working state of the optical system, the relative movement between the optical system installation bottom plate 10 and the vacuum closed box bottom plate 11 is free movement without resistance, so that the optical system installation bottom plate 10 cannot deform under stress, and the installation and adjustment accuracy of the optical system at low temperature is ensured.