Tank cover opening device for liquid nitrogen tank

Abstract

The present application relates to the field of cryogenic storage technology, and discloses a tank cover opening device for a liquid nitrogen tank, comprising a fixed bracket, a lead screw, a pressure arm, a lead screw nut, a first limit block and a driving device, wherein the installation position of the fixed bracket remains fixed relative to the tank body of the liquid nitrogen tank; the lead screw is vertically arranged and rotatably connected to the fixed bracket; the first end of the pressure arm is connected to the tank cover of the liquid nitrogen tank; the lead screw nut is fixed to the pressure arm and sleeved on the lead screw; the first limit block is fixed to the fixed bracket and is lower than the lifting stroke of the pressure arm; the driving device is used to drive the lead screw to rotate in a first direction, in the first stage of the rotation of the lead screw, the lead screw nut moves upward along the axial direction of the lead screw, driving the pressure arm to lift upward; in the second stage of the rotation of the lead screw, the lead screw nut rotates with the lead screw, driving the tank cover to move horizontally to open the tank mouth.

Description

Technical Field

[0001] The present application relates to the field of cryogenic storage technology, for example, to a tank cover opening device for a liquid nitrogen tank. Background Art

[0002] A liquid nitrogen tank is a cryogenic storage device that uses liquid nitrogen to create a cryogenic environment. Liquid nitrogen tanks are usually equipped with a tank opening and a tank cover at the top, and biological samples are stored and retrieved by opening the tank cover. Since the temperature of the liquid nitrogen tank is relatively low and the tank cover is relatively heavy, the tank cover is usually opened mechanically.

[0003] The Chinese patent application with publication number CN210065111U discloses a multifunctional cover opening device, including: a rotary drive mechanism, a lifting mechanism, and a cover lifting mechanism, wherein the rotary drive mechanism includes an end face bearing, a rotary column and a first drive mechanism; the lifting mechanism includes a ball screw, a third transmission pulley, a lifting servo motor, a fourth transmission pulley and a lifting slide rail, and the cover lifting mechanism includes a cantilever body and a servo motor. When the small cover of the liquid nitrogen tank needs to be opened, the servo motor is started, and the rotary column rotates around the center line of the end face bearing. When the induction block touches the first position sensor, the first position sensor is pressed. One servo motor stops, the lifting servo motor starts, and the cantilever body moves downward along the ball screw. When the induction block touches the third sensor during the movement, the lifting servo motor stops, and the electromagnet under the small cover extraction rod is energized to generate magnetism, thereby sucking the small cover of the liquid nitrogen tank. After the small cover is sucked, the lifting servo motor starts again, and one end of the cantilever body moves upward along the ball screw through the nut. After lifting the small cover of the liquid nitrogen tank, the first servo motor starts, and the rotating column rotates around the axis of the end face bearing. When the induction block touches the second sensor, the first servo motor stops, and the extraction action of the small cover of the liquid nitrogen tank is completed.

[0004] In the process of implementing the embodiments of the present disclosure, it is found that there are at least the following problems in the related art:

[0005] The lifting and rotation of the can lid both require separate drive mechanisms, which is not only costly, but also has poor operational stability in a low-temperature environment for a lid opening device with multiple drive mechanisms. Summary of the invention

[0006] In order to provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. The summary is not an extensive review, nor is it intended to identify key / critical components or delineate the scope of protection of these embodiments, but rather serves as a prelude to the detailed description that follows.

[0007] The disclosed embodiment provides a tank cover opening device for a liquid nitrogen tank to solve the problem of how to reduce the cost of the tank cover opening device and improve its operating stability.

[0008] In some embodiments, the tank cover opening device for the liquid nitrogen tank includes a fixed bracket, a lead screw, a pressure arm, a lead screw nut, a first limit block and a driving device, wherein the fixed bracket is installed at a fixed position relative to the tank body of the liquid nitrogen tank; the lead screw is vertically arranged and rotatably connected to the fixed bracket; the pressure arm has a first end connected to the tank cover of the liquid nitrogen tank; the lead screw nut is fixed to the pressure arm and sleeved on the lead screw; the first limit block is fixed to the fixed bracket, the height of the first limit block is lower than the lifting stroke of the pressure arm, and the first limit block can limit the pressure arm to move along the first rotation along the lead screw The first stop block is used to move the lead screw nut upward along the axial direction of the lead screw, thereby driving the pressure arm to lift upward; a driving device is used to drive the lead screw to rotate in a first direction. In the first stage of the rotation of the lead screw, the lead screw nut moves upward along the axial direction of the lead screw under the limitation of the first limit block, thereby driving the pressure arm to lift upward to make the tank cover break away from the contact with the tank mouth; in the second stage of the rotation of the pressure arm beyond the first limit block into the lead screw, the lead screw nut rotates with the lead screw, and the pressure arm swings with the lead screw nut, thereby driving the tank cover to move horizontally to open the tank mouth.

[0009] In the disclosed embodiment, the fixed bracket can be fixed to the tank body of the liquid nitrogen tank, or to the wall or floor of the environment where the liquid nitrogen tank is located, as long as the fixed bracket remains fixed during the process of opening and closing the tank cover with liquid nitrogen. The lead screw and the lead screw nut cooperate. When the lead screw rotates, if the lead screw nut does not rotate, the lead screw nut slides relative to the lead screw along the length direction of the lead screw. The lead screw is rotatably connected to the fixed bracket, which means that the lead screw is fixed to the fixed bracket and can rotate around the axis of the lead screw. The lead screw nut is fixed to the pressure arm, and the sliding movement or rotational movement of the lead screw nut relative to the lead screw is transmitted to the pressure arm, driving the pressure arm to rise or fall or swing. The first end of the pressure arm is connected to the tank cover, and the lifting or swinging of the pressure arm is transmitted to the tank cover. The first limit block is fixed to the fixed bracket, which means that the position of the first limit block remains fixed relative to the fixed bracket, and is not strictly limited to being connected to the fixed bracket by screw connection or welding. The first direction is the direction of rotation of the lead screw during the process of opening the tank cover. Taking the process of opening the tank lid as an example, the driving device drives the lead screw to rotate, and the pressure arm may be lifted or swung along with the lead screw nut. At this time, the height of the pressure arm does not exceed the first limit block, and the pressure arm cannot swing under the limiting effect of the first limit block, and can only move upward. The pressure arm drives the tank lid to move upward, so that the tank lid is out of contact with the tank mouth of the liquid nitrogen tank. When the pressure arm exceeds the first limit block, the work done by the swing of the pressure arm is less than the work done by the lifting of the pressure arm, and the pressure arm swings along with the rotation of the lead screw nut, driving the tank lid to move horizontally, thereby opening the tank mouth.

[0010] In some embodiments, the tank cover opening device for the liquid nitrogen tank also includes a second limit block, which is fixed to the fixed bracket and has a height higher than the first limit block; the driving device is also used to drive the lead screw to rotate in a second direction, driving the pressure arm to swing back to just above the tank mouth, and the second limit block can limit the pressure arm to continue to rotate along the second direction with the lead screw, so that the lead screw nut is displaced downward in the axial direction of the lead screw, thereby driving the pressure arm to descend until it is buckled onto the tank mouth.

[0011] In some embodiments, the tank cover opening device for the liquid nitrogen tank also includes a third limit block, and the third limit block is fixed to the fixed bracket. When the pressure arm drives the tank cover to open outward from directly above the tank mouth of the liquid nitrogen tank to a maximum angle, the pressure arm abuts against the third limit block.

[0012] In some embodiments, the fixed bracket includes a bottom plate, a side plate, a top plate and a bearing, wherein the bottom plate is fixed to the tank body of the liquid nitrogen tank; the side plate extends upward from the bottom plate; the top plate is connected to the side plate and arranged opposite to the bottom plate; the bearing is fixed to the bottom plate and / or the top plate; the lead screw is connected to the bearing so that the lead screw is rotatably connected to the fixed bracket.

[0013] In some embodiments, the side panel includes a first side panel and a second side panel, wherein the first side panel is connected to the bottom panel at one end and to the top panel at the other end; the second side panel is arranged opposite to the first side panel, and the bottom panel, the top panel, the first side panel and the second side panel enclose a pressure arm movement space, and the pressure arm passes through the pressure arm movement space.

[0014] In some embodiments, the second limiting block is fixed to the first side plate.

[0015] In some embodiments, the third limiting block is fixed to the second side plate.

[0016] In some embodiments, the driving device includes a first gear, a second gear, a driving motor and a transmission belt, wherein the first gear is fixed to the lead screw; the second gear is fixed to the base plate and is located in the same plane as the first gear; the driving motor is fixed to the base plate and is transmission-connected to the second gear; and the transmission belt surrounds the first gear and the second gear to transmit the rotation of the second gear to the first gear.

[0017] In some embodiments, the tank cover opening device for the liquid nitrogen tank further includes a tensioning wheel, which is fixed to the bottom plate, and the tensioning wheel causes the transmission belt to be recessed inward or protrude outward to tension the transmission belt.

[0018] In some embodiments, the tank cover opening device for the liquid nitrogen tank also includes a spring, which is fixed to the bottom plate. When the pressure arm is located directly above the tank mouth of the liquid nitrogen tank, the spring is located directly below the second end of the pressure arm.

[0019] In some embodiments, the pressure arm includes a pressure arm body, a through hole is opened in the middle of the pressure arm body, and the lead screw nut is fixed in the through hole.

[0020] In some embodiments, the pressure arm also includes a tank cover connecting plate and a plurality of shock absorbers, wherein the tank cover connecting plate is fixed to the first end of the pressure arm body, and the tank cover connecting plate is arranged opposite to the tank cover; a plurality of shock absorbers are arranged between the tank cover and the tank cover connecting plate along the circumference of the tank cover, and one end of each of the shock absorbers is fixed to the tank cover connecting plate, and the other end is fixed to the tank cover.

[0021] The tank cover opening device for a liquid nitrogen tank provided in the embodiment of the present disclosure can achieve the following technical effects:

[0022] 1. The action of opening the lid of the liquid nitrogen tank is decomposed into an upward lifting action and a horizontal moving action, which can effectively avoid the friction between the lid or the sealing ring and the tank mouth during the process of opening the lid, reduce the wear of the lid and the sealing ring, and increase the service life of the liquid nitrogen tank;

[0023] 2. The cover of the liquid nitrogen tank is opened in a translational manner, which reduces the space required to open the cover and facilitates the storage and use of the liquid nitrogen tank;

[0024] 3. The lifting and translation movements of the liquid nitrogen tank cover are realized by only one set of driving device, which saves costs and improves the working stability of the liquid nitrogen tank.

[0025] The above general description and the following description are exemplary and explanatory only and are not intended to limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] One or more embodiments are exemplarily described by corresponding drawings, which do not limit the embodiments. Elements with the same reference numerals in the drawings are shown as similar elements, and the drawings do not constitute a scale limitation, and wherein:

[0027] Figure 1 It is an overall schematic diagram of the tank cover opening device for a liquid nitrogen tank provided by an embodiment of the present disclosure and the cooperation with the liquid nitrogen tank;

[0028] Figure 2 It is a schematic diagram of the use state of the tank cover opening device for the liquid nitrogen tank provided by the embodiment of the present disclosure when the tank cover is closed;

[0029] Figure 3It is a schematic diagram of the use state of the tank cover opening device for the liquid nitrogen tank provided by the embodiment of the present disclosure when the tank cover is opened;

[0030] Figure 4 is a comparison diagram of the use states of the tank cover opening device for a liquid nitrogen tank provided by an embodiment of the present disclosure when the tank cover is opened and when the tank cover is closed;

[0031] Figure 5 It is a structural schematic diagram of a tank cover opening device for a liquid nitrogen tank provided by an embodiment of the present disclosure;

[0032] Figure 6 is a schematic structural diagram of another tank cover opening device for a liquid nitrogen tank provided by an embodiment of the present disclosure;

[0033] Figure 7 is a schematic structural diagram of another tank cover opening device for a liquid nitrogen tank provided by an embodiment of the present disclosure;

[0034] Figure 8 is a schematic structural diagram of a tank cover opening device for a liquid nitrogen tank provided in an embodiment of the present disclosure with the bottom plate removed;

[0035] Fig. 9 It is a schematic structural diagram of the tank cover opening device for the liquid nitrogen tank provided in an embodiment of the present disclosure after the side plates and the top plate are removed.

[0036] Reference numerals:

[0037] 10: tank body; 20: tank cover;

[0038] 100: fixed bracket; 110: bottom plate; 120: side plate; 121: first side plate; 122: second side plate; 130: top plate; 140: bearing;

[0039] 210: lead screw;

[0040] 300: pressing arm; 310: pressing arm body; 320: tank cover connecting plate; 330: shock absorber;

[0041] 410: first limit block; 420: second limit block; 430: third limit block;

[0042] 500: driving device; 510: first gear; 520: second gear; 530: driving motor; 540: driving belt; 550: tensioning wheel;

[0043] 600: Spring. DETAILED DESCRIPTION

[0044] In order to be able to understand the features and technical contents of the embodiments of the present disclosure in more detail, the implementation of the embodiments of the present disclosure is described in detail below in conjunction with the accompanying drawings. The attached drawings are for reference only and are not used to limit the embodiments of the present disclosure. In the following technical description, for the convenience of explanation, a full understanding of the disclosed embodiments is provided through multiple details. However, one or more embodiments can still be implemented without these details. In other cases, to simplify the drawings, well-known structures and devices can be simplified for display.

[0045] The terms "first", "second", etc. in the specification and claims of the embodiments of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so that the embodiments of the embodiments of the present disclosure described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0046] In the embodiments of the present disclosure, the terms "upper", "lower", "inside", "middle", "outside", "front", "back" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. These terms are mainly intended to better describe the embodiments of the present disclosure and their embodiments, and are not intended to limit the indicated devices, elements or components to have a specific direction, or to be constructed and operated in a specific direction. Moreover, in addition to being used to indicate directions or positional relationships, some of the above terms may also be used to indicate other meanings. For example, the term "upper" may also be used to indicate a certain dependency or connection relationship in certain circumstances. For those of ordinary skill in the art, the specific meanings of these terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0047] In addition, the terms "disposed", "connected", and "fixed" should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0048] Unless otherwise stated, the term "plurality" means two or more.

[0049] In the embodiment of the present disclosure, the character " / " indicates that the preceding and following objects are in an "or" relationship. For example, A / B indicates: A or B.

[0050] The term "and / or" is a description of the association relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or, A and B.

[0051] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present disclosure may be combined with each other.

[0052] Combination Figure 1-9 As shown, the embodiment of the present disclosure provides a tank cover opening device for a liquid nitrogen tank, including a fixed bracket 100, a lead screw 210, a pressure arm 300, a lead screw nut, a first limit block 410 and a driving device 500, wherein the fixed bracket 100 is installed at a fixed position relative to the tank body 10 of the liquid nitrogen tank; the lead screw 210 is vertically arranged and rotatably connected to the fixed bracket 100; the pressure arm 300 has a first end connected to the tank cover 20 of the liquid nitrogen tank; the lead screw nut is fixed to the pressure arm 300, and the lead screw nut cooperates with the lead screw 210 to make the pressure arm 300 rise and fall and swing; the first limit block 410, Fixed to the fixed bracket 100, the height of the limit block is lower than the lifting stroke of the pressure arm 300, and the first limit block 410 is used to prevent the pressure arm 300 from swinging during the lifting process; the driving device 500 is used to drive the lead screw 210 to rotate. In the first stage of the rotation of the lead screw 210, the lead screw nut rotates relative to the lead screw 210, and the pressure arm 300 is lifted upward to make the tank cover 20 break away from the contact with the tank mouth and make the pressure arm 300 exceed the limit block. In the second stage of the rotation of the screw, the lead screw nut rotates with the lead screw 210, and the pressure arm 300 swings with the lead screw nut, driving the tank cover 20 to rotate to open the tank mouth.

[0053] In the embodiment of the present disclosure, the fixing bracket 100 is fixed to the tank body 10 of the liquid nitrogen tank, which means that the relative position of the fixing bracket 100 and the tank body 10 of the liquid nitrogen tank remains fixed. For example, the fixing bracket 100 can be fixed to the tank body 10 of the liquid nitrogen tank, or it can be fixed to the wall or floor of the environment where the liquid nitrogen tank is located, as long as the fixing bracket 100 remains fixed during the process of opening and closing the tank cover 20 of the liquid nitrogen. The lead screw 210 cooperates with the lead screw nut. When the lead screw 210 rotates, if the lead screw nut does not rotate, the lead screw nut slides relative to the lead screw 210 along the length direction of the lead screw 210. The lead screw 210 is rotatably connected to the fixing bracket 100, which means that the lead screw 210 is fixed to the fixing bracket 100 and can rotate around the axis of the lead screw 210. The lead screw nut is fixed to the pressure arm 300, and the sliding motion or rotational motion of the lead screw nut relative to the lead screw 210 is transmitted to the pressure arm 300, driving the pressure arm 300 to rise or fall or swing. The first end of the pressing arm 300 is connected to the tank cover 20, and the lifting or swinging of the pressing arm 300 is transmitted to the tank cover 20. The first limit block 410 is fixed to the fixed bracket 100, which means that the position of the first limit block 410 remains fixed relative to the fixed bracket 100, and is not strictly limited to being connected to the fixed bracket 100 by screw connection or welding. Taking the process of opening the tank cover 20 as an example, the driving device 500 drives the lead screw 210 to rotate, and the pressing arm 300 may be lifted or swung along with the lead screw nut. Without considering the influence of the friction force of the tank mouth, the work done by driving the pressing arm 300 to swing is less than the work done by raising the height of the pressing arm 300, so the pressing arm 300 is more inclined to swing. However, at this time, the height of the pressing arm 300 does not exceed the first limit block 410, and the pressing arm 300 cannot swing under the limiting effect of the first limit block 410, and can only move upward. The pressing arm 300 drives the tank cover 20 to move upward, so that the tank cover 20 is out of contact with the tank mouth of the liquid nitrogen tank. When the pressing arm 300 exceeds the first limit block 410, the work done by the swinging of the pressing arm 300 is less than the work done by the lifting of the pressing arm 300, and the pressing arm 300 swings with the rotation of the lead screw nut, driving the tank cover 20 to move horizontally, thereby opening the tank mouth.

[0054] Optionally, the force required for the lead screw nut to drive the pressure arm 300 to swing is less than the friction between the lead screw nut and the lead screw 210. In the absence of a limiting device to stop the swing of the pressure arm, the lead screw nut drives the pressure arm 300 to rotate with the lead screw nut. In the process of opening the tank cover, under the limiting action of the first limiting block, the pressure arm 300 first rises and then swings. In the process of closing the tank cover, the pressure arm 300 first swings and then falls. This arrangement makes the movement of the pressure arm 300 clearer and improves the working stability of the tank cover opening device. For different pressure arms, the static friction required to make it swing can be measured through multiple tests. For the friction between the lead screw and the lead screw nut, the length of the lead screw nut, the thread chamfer of the lead screw nut and the lead screw, and the surface roughness between the lead screw nut and the lead screw can be used to adjust it so that it is greater than the static friction required to make the pressure arm swing measured by the test.

[0055] Optionally, the tank cover opening device further comprises a fourth limit block, which is fixed to the fixed bracket 100. After the pressing arm 300 moves upward beyond the first limit block 410, it abuts against the fourth limit block and can only swing under the limiting action of the fourth limit block and cannot continue to move upward.

[0056] The first limit block 410 is used to limit the swing of the pressing arm 300 in the horizontal direction, so that the pressing arm 300 can only be lifted upward in the first stage of the rotation of the lead screw 210, and the fourth limit block is used to limit the lifting of the pressing arm 300 in the vertical direction, so that the pressing arm 300 can only swing in the second stage of the rotation of the lead screw 210, and cannot continue to be lifted upward. The lead screw 210 rotates in the same direction in the first stage and the second stage, and the main basis for dividing the first stage and the second stage is the action of the pressing arm 300 when the lead screw 210 rotates. Through the cooperation of the first limit block 410 and the fourth limit block, the pressing arm 300 moves in the vertical direction and rotates in the horizontal direction in the first stage and the second stage of the screw rotation, respectively. The fourth limit block can make the action of the pressing arm 300 clearer and improve the reliability of the operation of the tank cover opening device.

[0057] Optionally, the tank cover opening device further comprises a limiting nut, which is sleeved on the lead screw 210 and located above the lead screw nut. After the pressure arm 300 moves upward beyond the first limiting block 410, the lead screw nut abuts against the limiting nut.

[0058] During the process of opening the tank cover 20, the pressure arm 300 moves upward to a certain distance and then the lead screw nut abuts against the limit nut. The lead screw nut cannot continue to move upward under the limiting action of the limit nut, and thus cannot rotate relative to the screw. At this time, the lead screw nut rotates synchronously with the lead screw 210, thereby driving the pressure arm 300 to swing. By setting the limit nut, on the one hand, the action of the pressure arm 300 can be made clearer and the reliability of the tank cover opening device can be improved. On the other hand, the position of the limit nut on the lead screw 210 can be adjusted by rotating the limit nut. Changing the position of the limit nut on the lead screw 210 also changes the stroke of the lead screw nut on the lead screw 210, and further changes the stroke of the pressure arm 300. In this way, the lifting stroke of the tank cover opening device is adjustable, which reduces the difficulty of debugging the tank cover opening device and improves the operability and ease of use of the tank cover opening device.

[0059] Optionally, the rotational friction between the limit nut and the lead screw 210 is greater than the friction between the lead screw nut and the lead screw 210. Different friction between the nut and the screw can be achieved by a variety of different means, for example, the roughness of the inner surface of the limit nut is greater than the roughness of the inner surface of the lead screw nut, or the thread length of the limit nut is greater than the thread length of the lead screw nut, and the part of the lead screw nut in contact with the lead screw 210 is coated with grease.

[0060] During the operation of the tank cover opening device, the lead screw nut and the lead screw 210 need to rotate relative to each other frequently, and the limit nut only needs to rotate relative to the lead screw 210 when the stroke of the pressure arm 300 needs to be adjusted. The friction between the lead screw nut and the lead screw 210 is less than the friction between the limit nut and the lead screw 210, so that the lifting action of the pressure arm 300 can be smoother, and the position of the limit nut is relatively fixed. In this way, the movement of the tank cover opening device can be made more stable.

[0061] Optionally, an elastic gasket is provided between the lead screw nut and the limit nut. The elastic gasket is attached to a side of the lead screw nut in contact with the limit nut, and / or a side of the limit nut in contact with the lead screw nut. In this way, thread damage caused by rigid contact between the lead screw nut and the limit nut can be avoided, and running noise caused by contact between the lead screw nut and the limit nut can also be avoided.

[0062] Optionally, there are two limit nuts, and the two limit nuts are pressed against each other to limit the lead screw nut.

[0063] Two limit nuts are provided, and the two limit nuts are locked with each other. In this way, when the lifting stroke of the pressure arm 300 needs to be adjusted, it can be achieved by adjusting the positions of the two limit nuts in sequence. During the normal operation of the tank cover opening device, the two phase nuts are pressed against each other to keep the limit nut fixed in the position of the screw rod, prevent the lead screw nut from contacting the limit nut for a long time to change the position of the limit nut, and improve the operating stability of the tank cover opening device.

[0064] Optionally, an elastic gasket is provided between the two limiting nuts, so that the two limiting nuts can be pressed against each other better and remain fixed at the position of the screw rod.

[0065] Optionally, after the pressure arm 300 moves upward beyond the first limit block 410, the lead screw nut is located at the uppermost end of the thread of the lead screw 210. That is, the thread length of the lead screw 210 is the first length, which is less than the length of the lead screw 210. After the pressure arm 300 moves upward beyond the first limit block 410, the lead screw nut moves to the uppermost end of the thread of the lead screw 210. At this time, the lead screw nut cannot rotate relative to the screw, but can only rotate with the lead screw 210, thereby driving the pressure arm 300 to swing.

[0066] Optionally, the tank cover opening device 20 for the liquid nitrogen tank also includes a second limit block 420, which is fixed to the fixed bracket and has a height higher than the first limit block; the driving device is also used to drive the lead screw to rotate in a second direction, and when driving the pressure arm 300 to swing back to just above the tank mouth, the second limit block can limit the pressure arm to continue to rotate along the second direction with the lead screw, so that the lead screw nut moves downward in the axial direction of the lead screw, thereby driving the pressure arm to descend until it is buckled onto the tank mouth.

[0067] During the closing process of the tank cover 20, the driving device drives the lead screw to rotate in the second direction, and the pressing arm 300 drives the tank cover 20 to move from the position where the tank mouth is opened to just above the tank mouth of the liquid nitrogen tank. At this time, the pressing arm 300 abuts against the second limit block 420. The second limit block 420 is provided, so that the tank cover opening device can be accurately positioned just above the tank mouth when closing the tank cover 20. The second limit block is provided to realize the positioning of the swing of the pressing arm 300 during the closing process of the tank cover, so that the tank cover opening device can realize the function of closing the tank cover, enriching the function of the tank cover opening device 20.

[0068] Optionally, the tank cover opening device for the liquid nitrogen tank further includes a third limit block 430, which is fixed to the fixed bracket. When the pressure arm 300 drives the tank cover 20 to open outward from directly above the tank mouth of the liquid nitrogen tank to a maximum angle, the pressure arm 300 abuts against the third limit block 430.

[0069] The third limiting block 430 can be provided to limit the position of the pressing arm 300 when the tank cover 20 is fully opened, thereby improving the reliability of the tank cover opening device.

[0070] Optionally, the fixed bracket 100 includes a bottom plate 110, a side plate 120, a top plate 130 and a bearing 140, wherein the bottom plate 110 is fixed to the tank body 10 of the liquid nitrogen tank; the side plate 120 extends upward from the bottom plate 110; the top plate 130 is connected to the side plate and arranged opposite to the bottom plate 110; the bearing 140 is fixed to the bottom plate 110 and / or the top plate 130, and the lead screw 210 is connected to the bearing 140 so that the lead screw 210 is rotatably connected to the fixed bracket 100.

[0071] The bottom plate 110 is fixed to the tank body 10 of the liquid nitrogen tank, which means that the bottom plate 110 is fixed relative to the tank body 10 of the liquid nitrogen tank, and is not strictly limited to being fixedly connected to the tank body 10 of the liquid nitrogen tank. With the bottom plate 110, the tank cover opening device has a stable fulcrum when lifting the tank cover 20. This arrangement makes the structure of the tank cover opening device more stable.

[0072] Optionally, the side panel 120 includes a first side panel 121 and a second side panel 122, wherein the first side panel 121 is connected to the bottom panel 110 at one end and to the top panel 130 at the other end; the second side panel 122 is arranged opposite to the first side panel 121, and the bottom panel 110, the top panel 130, the first side panel 121 and the second side panel 122 enclose a pressure arm movement space, and the pressure arm 300 passes through the pressure arm movement space.

[0073] The first side plate 121, the second side plate 122, the top plate 130 and the bottom plate 110 are enclosed in a gantry type, the lead screw 210 extends from the top plate 130 to the bottom plate 110, and the pressure arm 300 is penetrated by the lead screw 210. With this arrangement, the structure of the fixed bracket 100 is more stable. The pressure arm 300 completes the movement and swinging movement in the pressure arm movement space, which means that the pressure arm 300 passes through the gantry type fixed bracket 100, and when the pressure arm 300 moves, part of the pressure arm 300 moves in the pressure arm movement space.

[0074] Optionally, the second limit block 420 is fixed to the first side plate 121, or a portion of the first side plate 121 is the second limit block 420, and the movement of the pressing arm 300 is limited and positioned by the second side plate 121, or the second limit block 420 is integrally formed with the first side plate 121. This form effectively utilizes the existing structure of the fixed bracket, has a simple structure and reliable functions.

[0075] Optionally, the third limit block 430 is fixed to the second side plate 122, or part of the second side plate 122 is the third limit block 430, and the movement of the pressing arm 300 is limited and positioned by the second side plate 122, or the third limit block 430 is integrally formed with the second side plate 122. This form effectively utilizes the existing structure of the fixed bracket, has a simple structure and reliable functions.

[0076] Optionally, the driving device 500 includes a first gear 510, a second gear 520, a driving motor 530 and a transmission belt 540, wherein the first gear 510 is fixed to the lead screw 210; the second gear 520 is fixed to the base plate 110 and is located in the same plane as the first gear 510; the driving motor 530 is fixed to the base plate 110 and is transmission-connected to the second gear 520; and the transmission belt 540 surrounds the first gear 510 and the second gear 520 to transmit the rotation of the second gear 520 to the first gear 510.

[0077] The inside of the liquid nitrogen tank is a low temperature environment, and the environment where the liquid nitrogen tank is located is also a low temperature environment. In a low temperature environment, the belt drive form allows a certain amount of flexibility between the movements of each component, which improves the reliability of the tank cover opening device compared to the gear drive form.

[0078] Optionally, the lead screw 210 extends below the bottom plate 110, and the first gear 510 is fixed to the end below the cylinder screw. In this way, the first gear 510 and the second gear 520 are both located below the bottom plate 110, which not only effectively utilizes the space, but also avoids the gears from being exposed above the bottom plate 110, thereby improving the safety of the can lid opening device.

[0079] Optionally, the tank cover opening device further includes a tensioning wheel 550 fixed to the bottom plate 110 , and the tensioning wheel 550 causes the transmission belt 540 to be recessed inward or protrude outward to tension the transmission belt 540 .

[0080] A tensioning wheel 550 is provided to keep the transmission belt 540 in a tensioned state. After the tank cover opening device has been running for a long time, the belt may become loose. The tension of the belt can be adjusted by adjusting the tensioning wheel 550. There is no need to replace the belt, thereby reducing the use and maintenance costs of the tank cover opening device.

[0081] Optionally, the tank cover opening device further includes a spring 600 fixed to the bottom plate 110 , and when the pressing arm 300 is located directly above the tank opening of the liquid nitrogen tank, the spring 600 corresponds to the second end of the pressing arm 300 .

[0082] When the tank cover 20 is closed, the pressing force of the tank cover 20 on the tank mouth comes from the deadweight of the tank cover 20 on the one hand, and from the downward pressure of the pressing arm 300 on the other hand. A spring 600 is provided, and the spring 600 pushes the second end of the pressing arm 300 upward, and the pressure is transmitted to the first end of the pressing arm 300 connected to the tank cover 20 through the lever formed by the pressing arm 300. The position where the pressing arm 300 is fixedly connected to the lead screw nut becomes the fulcrum of the lever. In this way, it is beneficial for the pressing arm 300 to press the tank cover 20 against the tank mouth, ensure that the tank cover 20 is in close contact with the tank mouth, and improve the thermal insulation performance of the liquid nitrogen tank. At the same time, it can also avoid that the pressure on both ends of the pressing arm 300 is uneven, causing the pressing arm 300 to deform or damage the lead screw 210 and the lead screw nut.

[0083] Optionally, the distance between the position where the pressure arm 300 is connected to the lead screw nut and the second end is greater than the distance between the position where the pressure arm 300 is connected to the lead screw nut and the first end.

[0084] In this way, the upward elastic force of the spring 600 on the pressing arm 300 is amplified by the pressing arm 300, so that the pressing arm 300 can better press the tank cover 20, further improving the heat preservation effect of the liquid nitrogen tank.

[0085] Optionally, the pressure arm 300 includes a pressure arm body 310 , which is provided with a through hole, and the lead screw 210 is fixed in the through hole, and the lead screw 210 passes through the through hole.

[0086] The pressure arm 300 is provided with a through hole, and the pressure arm 300 is evenly stressed. The lead screw 210 passes through the through hole, and the pressure arm 300 is not easy to separate from the fixing bracket 100. Such a setting form can effectively improve the structural stability of the can lid opening device.

[0087] Optionally, the pressure arm 300 also includes a tank cover connecting plate 320 and a shock absorber 330, wherein the tank cover connecting plate 320 is fixed to the first end of the pressure arm body 310, and the tank cover connecting plate 320 is arranged opposite to the tank cover 20; the shock absorber 330 has one end fixed to the tank cover connecting plate 320 and the other end fixed to the tank cover 20, wherein the number of the shock absorbers 330 is multiple, and the multiple shock absorbers 330 are arranged along the circumference of the tank cover 20.

[0088] The tank cover connecting plate 320 is connected to the tank cover 20 through the shock absorber 330, so that the tank cover opening device can be applied to the transformation of the old liquid nitrogen tank, and the use scenarios of the tank cover opening device can be enriched. Multiple shock absorbers 330 are arranged along the circumference of the tank cover 20, so that when the tank cover 20 is closed, even if the pressure arm 300 is not parallel to the plane where the tank cover 20 is located, the tank cover 20 can also be flush with the tank mouth and press the tank mouth under the different length changes of the multiple shock absorbers 330. In addition, multiple shock absorbers 330 also play the role of spring 600, and the pressure arm 300 is connected to the tank cover 20 through the spring 600. Under the buffering of the spring 600, the contact pressure between the tank cover 20 and the tank mouth when the tank cover 20 is pressed against the tank mouth can be controlled within a safe range. Multiple shock absorbers 330 are provided, and the rigid contact between the tank cover 20 and the tank mouth when the tank cover 20 is closed can also be buffered, reducing the noise when the tank cover 20 is closed, and protecting the sealing ring between the tank cover 20 and the tank mouth.

[0089] The above description and the accompanying drawings sufficiently illustrate the embodiments of the present disclosure to enable those skilled in the art to practice them. Other embodiments may include structural and other changes. The embodiments represent only possible variations. Unless explicitly required, individual components and functions are optional, and the order of operations may vary. Portions and features of some embodiments may be included in or replace portions and features of other embodiments. The embodiments of the present disclosure are not limited to the structures described above and shown in the accompanying drawings, and various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A tank cover opening device for a liquid nitrogen tank, characterized in that: include: A fixed bracket, the installation position of which remains fixed relative to the tank body of the liquid nitrogen tank; A lead screw rod is vertically arranged and rotatably connected to the fixed bracket; A pressing arm, a first end of which is connected to a tank cover of the liquid nitrogen tank; A lead screw nut, fixed to the pressure arm and sleeved on the lead screw; A first limit block is fixed to the fixed bracket, the height of the first limit block is lower than the lifting stroke of the pressure arm, and the first limit block can limit the pressure arm to rotate along the first turning direction with the lead screw, so that the lead screw nut moves upward in the axial direction of the lead screw, thereby driving the pressure arm to lift upward; A driving device is used to drive the lead screw to rotate in a first direction. In the first stage of the rotation of the lead screw, the lead screw nut moves upward along the axial direction of the lead screw under the limitation of the first limit block, driving the pressure arm to lift upward so that the tank cover is out of contact with the tank mouth; when the pressure arm exceeds the first limit block and enters the second stage of the rotation of the lead screw, the lead screw nut rotates with the lead screw, and the pressure arm swings with the lead screw nut, thereby driving the tank cover to move horizontally to open the tank mouth; The force required by the lead screw nut to drive the pressure arm to swing is smaller than the friction force between the lead screw nut and the lead screw.

2. The can lid opening device according to claim 1, characterized in that: Also includes: A second limiting block, fixed to the fixing bracket and having a height higher than that of the first limiting block; The driving device is also used to drive the lead screw to rotate in a second direction, and when the pressure arm is driven to swing back to just above the tank mouth, the second limit block can limit the pressure arm to continue to rotate along the second direction with the lead screw, so that the lead screw nut is displaced downward in the axial direction of the lead screw, thereby driving the pressure arm to descend until it is buckled onto the tank mouth.

3. The can lid opening device according to claim 1, characterized in that: Also includes: The third limit block is fixed to the fixed bracket. When the pressure arm drives the tank cover to open outward from directly above the tank mouth of the liquid nitrogen tank to a maximum angle, the pressure arm abuts against the third limit block.

4. The can lid opening device according to claim 3, characterized in that: The fixing bracket comprises: A bottom plate, fixed to the tank body of the liquid nitrogen tank; A side plate extending upward from the bottom plate; A top plate connected to the side plates and arranged opposite to the bottom plate; A bearing, fixed to the bottom plate and / or the top plate; The lead screw is connected to the bearing so that the lead screw is rotatably connected to the fixed bracket.

5. The can lid opening device according to claim 4, characterized in that: The side panel comprises: A first side plate, one end of which is connected to the bottom plate, and the other end of which is connected to the top plate; A second side plate is arranged opposite to the first side plate, The bottom plate, the top plate, the first side plate and the second side plate enclose a pressing arm movement space, and the pressing arm passes through the pressing arm movement space.

6. The can lid opening device according to claim 5, characterized in that: The second limiting block is fixed to the first side plate.

7. The can lid opening device according to claim 5, characterized in that: The third limiting block is fixed to the second side plate.

8. The can lid opening device according to any one of claims 4 to 7, characterized in that: The driving device comprises: A first gear, fixed to the lead screw; A second gear, fixed to the bottom plate and located on the same plane as the first gear; A driving motor is fixed to the bottom plate and is transmission-connected to the second gear; A transmission belt is wound around the first gear and the second gear to transmit the rotation of the second gear to the first gear.

9. The can lid opening device according to claim 8, characterized in that: Also includes: The tensioning wheel is fixed to the bottom plate, and the tensioning wheel causes the transmission belt to be recessed inwards or protrude outwards so as to tension the transmission belt.

10. The can lid opening device according to any one of claims 4 to 7, characterized in that: Also includes: The spring is fixed to the bottom plate. When the pressure arm is located directly above the tank opening of the liquid nitrogen tank, the spring is located directly below the second end of the pressure arm.

11. The can lid opening device according to any one of claims 1 to 7, characterized in that: The pressing arm comprises: The pressure arm body has a through hole in the middle, and the lead screw nut is fixed in the through hole.

12. The can lid opening device according to claim 11, characterized in that: The pressing arm also includes: A tank cover connecting plate, fixed to the first end of the pressure arm body, the tank cover connecting plate being arranged opposite to the tank cover; A plurality of shock absorbers are arranged between the tank cover and the tank cover connecting plate along the circumference of the tank cover, and one end of each of the shock absorbers is fixed to the tank cover connecting plate, and the other end is fixed to the tank cover.

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