Low temperature check valve for aerospace

Abstract

This application relates to the field of check valves, and more particularly to a cryogenic check valve for aerospace applications. The valve includes a valve seat, a telescopic spring, a valve disc, a valve stem, and a seal. The valve seat has an inlet, an outlet, and a flow chamber, with the flow chamber connecting the inlet and outlet. The telescopic spring is disposed between the valve seat and the valve disc, and has a preload that causes the valve disc to abut against the valve seat. The valve seat has a through hole, and the valve stem is embedded in the through hole. One end of the valve stem extends into the flow chamber and is fixedly connected to a protrusion. The other end of the valve stem extends out of the through hole. The protrusion is located on the side of the valve disc away from the telescopic spring. The surface of the protrusion away from the valve stem axis has an abutment surface for abutting against the valve disc. The seal connects the valve body and the valve stem and provides a seal. This application utilizes the abutment surface of the protrusion to abut against the valve disc, eliminating the need for maintenance personnel to continuously press the large telescopic spring used in aerospace applications, thus saving maintenance personnel's physical effort and facilitating the maintenance of the check valve.

Description

Technical Field

[0001] This application relates to the field of check valves, and more particularly to a cryogenic check valve for aerospace applications. Background Technology

[0002] A check valve, also known as a one-way valve, ensures the unidirectional flow of a medium in a pipeline, preventing backflow. Check valves have a wide range of applications, such as small check valves built into irrigation sprinklers in agriculture, check valves in heaters used in daily life to prevent convection between hot and cold water, and large check valves frequently used in the aircraft and aerospace industries to mix fuels and oxidizers, ensuring the purity of the original fuel tank. However, because the mixed fuels transported in the aerospace industry, such as liquid nitrogen and liquid oxygen, need to remain liquid in a cryogenic environment, the quality requirements for check valves are very high.

[0003] Currently, check valves in the aerospace field require frequent and regular maintenance to ensure stable fuel delivery, prevent leaks, and meet actual aerospace quality requirements. A check valve mainly consists of a valve seat, a valve disc, and a spring connecting the valve disc and the valve seat. The valve disc, under the spring's elastic force, presses against the valve seat to close the check valve. During maintenance, the valve disc needs to be pressed to compress the spring, checking whether the contact surfaces between the valve disc and the valve seat have become flat due to long-term impact, affecting the seal, and whether the valve disc slides normally. However, because the check valves used for fuel delivery in the aerospace field are relatively large, typically between 30cm and 40cm in diameter, and the spring force is considerable, constantly pressing the valve disc for maintenance is quite inconvenient. Summary of the Invention

[0004] To facilitate the maintenance of check valves, this application provides a cryogenic check valve for aerospace applications.

[0005] The cryogenic check valve for aerospace applications provided in this application adopts the following technical solution:

[0006] A cryogenic check valve for aerospace applications includes a valve seat, a telescopic spring, and a valve disc slidably connected to the valve seat. The valve seat has an inlet, an outlet, and a flow cavity, the flow cavity connecting the inlet and the outlet. The telescopic spring is disposed between the valve seat and the valve disc, and has a preload force that causes the valve disc to press against the valve seat. When the valve disc presses against the valve seat, the flow cavity is not connected to the inlet and outlet. The valve seat also includes a valve stem and a seal. The valve seat has a through hole, the axis of which is perpendicular to the sliding direction of the valve disc. The valve stem is coaxially rotatably embedded in the through hole. One end of the valve stem extends into the flow cavity and is fixedly connected to a protrusion, while the other end of the valve stem extends out of the through hole. The protrusion is located on the side of the valve disc away from the telescopic spring. The surface of the protrusion away from the valve stem axis has an abutment surface for abutting against the valve disc. When the abutment surface abuts against the valve disc, the flow cavity connects the inlet and outlet. The seal connects the valve body and the valve stem and provides a seal, and the contact surfaces of the seal and the valve stem form a friction pair.

[0007] By adopting the above technical solution, when the check valve is working, the valve disc compresses the telescopic spring, connecting the inlet and outlet of the flow chamber. When the check valve is not working, the valve disc returns to its original position based on the elastic force of the telescopic spring and presses against the valve seat. During check valve maintenance, the maintenance personnel rotate the valve stem at the end opposite to the flow chamber, causing the protrusion to rotate until it abuts against the valve disc, keeping the valve disc in the open state. Alternatively, the valve disc can be pushed into the open state first, allowing the abutment surface to abut against the valve disc. This eliminates the need for maintenance personnel to continuously press the large telescopic spring used in aerospace applications, saving physical effort and facilitating check valve maintenance. Simultaneously, the friction pair between the valve stem and the seal allows the valve stem to remain stationary when not rotated by the maintenance personnel, and the seal ensures a tight seal between the valve stem and the valve seat, minimizing leakage of mixed fuels or other fuels flowing through the flow chamber, thus saving energy.

[0008] Preferably, the valve seat includes a valve body, a fixing block, and a flow guide. The inlet, outlet, and flow cavity are located in the valve body. The fixing block and the flow guide are both fixedly connected to the valve body and located within the flow cavity. The fixing block has a first limiting hole, and the flow guide has a second limiting hole coaxial with the first limiting hole. The valve disc includes a disc body and a valve shaft. The valve shaft is coaxially slidably embedded in the first and second limiting holes. The disc body is fixedly connected to the outer periphery of the valve shaft. The disc body is located between the fixing block and the flow guide, and the abutment surface is used to abut against the disc body.

[0009] By adopting the above technical solution, the valve body is located between the fixed block and the flow guide, and the valve shaft is simultaneously embedded in the first limiting hole and the second limiting hole, so that when the valve body slides with the valve shaft, both ends of the valve shaft can be limited, thereby reducing the probability of the valve shaft vibrating under the impact of the mixed fuel when the valve shaft slides to the open state, thereby reducing the probability of the valve shaft and valve body generating a radial force along the valve shaft, and thus improving the service life of the valve shaft.

[0010] Preferably, it also includes a ratchet and a coil spring. The fixing block is provided with a mounting hole that communicates with the first limiting hole. The valve stem is rotatably embedded in the mounting hole. The ratchet is coaxially rotatably connected to the surface of the valve stem near the valve stem via a rotating shaft. One end of the coil spring is fixedly connected to the rotating shaft, and the other end of the coil spring is fixedly connected to the valve stem.

[0011] The valve shaft is provided with multiple clearance grooves along its own axial direction. All clearance grooves are embedded with return springs. All return springs are connected to guide blocks. All guide blocks are provided with guide surfaces on two surfaces along the axial direction of the valve shaft. The two guide surfaces on the same guide block gradually approach each other as they move away from the valve shaft. The guide surfaces are used to slide against the fixed block.

[0012] The guide block is hinged to a pawl via a hinge shaft. The clearance groove is used for the pawl to engage. When the valve shaft slides away from the flow guide, the pawl is used to drive the ratchet to rotate.

[0013] By adopting the above technical solution, firstly, the valve stem is embedded in the mounting hole, and the ratchet and coil spring are located at the end of the valve stem near the valve shaft, reducing the probability of the mixed fuel directly impacting the ratchet and coil spring, causing failure. Secondly, when the valve shaft slides away from the guide shield, the pawl drives the ratchet to rotate. When the ratchet rotates, because the valve stem is fixed by the friction pair between it and the seal, and the coil spring is fixedly connected to one end of the valve stem, the other end of the coil spring gradually coils up through the rotation of the ratchet. Simultaneously, multiple guide blocks slide against the fixed block through the guide surface, allowing the elastic potential energy of the telescopic spring to be converted during the sliding contact between the guide surface and the fixed block. At the same time, the elastic force of the telescopic spring drives the valve shaft to slide, which in turn drives the ratchet to rotate, storing energy in the coil spring. This not only converts the elastic potential energy of the telescopic spring to a certain extent, reducing the loss of elastic potential energy caused by the impact of the telescopic spring's elastic potential energy on the valve body and improving energy utilization, but also reduces the impact of the valve body on the valve body under the action of the telescopic spring, thus improving the service life of the check valve. When the valve body abuts against the valve body, the pawl limits the ratchet, keeping the coil spring in a coiled state. This does not affect the degree to which the valve body abuts against the valve body via the preload of the extension spring. Since the valve shaft slides on the first limiting hole provided in the fixed block, and the coil spring and ratchet are located within the mounting hole, when the guide surface of the guide block slides against the fixed block, the pawl can enter into or slide out of the mounting hole along the axial direction of the valve shaft, and return to its original position based on the return spring, so that the pawl can engage with the ratchet.

[0014] When the valve shaft slides in the direction close to the guide shield, due to the gap between the clearance groove and the guide block, whenever the valve shaft slides a certain distance, the pawl slides a certain distance as well, so that the ratchet can rotate under the action of the coil spring, so as to convert the elastic potential energy of the coil spring into the kinetic energy of the ratchet to a certain extent, so that when the valve shaft moves in the direction away from the guide shield and the check valve closes, the coil spring can still be wound up to buffer the impact of the valve body on the valve body.

[0015] Preferably, a torsion spring is sleeved on the outer periphery of the hinge shaft, and the two ends of the torsion spring abut against the pawl and the guide block, respectively.

[0016] By adopting the above technical solution, when the valve shaft slides in the direction close to the guide shield, one end of the coil spring is fixedly connected to the valve stem, and the other end of the coil spring, based on the elastic deformation generated by the coiling of the spring, causes the ratchet to rotate and squeeze the pawl, causing the torsion spring to undergo elastic deformation. The torsion spring allows the pawl to quickly return to its original position after rotation, so that when the valve shaft slides in the direction away from the guide shield again, the pawl can engage the ratchet and drive the ratchet to rotate.

[0017] Preferably, the valve stem has a mounting groove coaxially provided on the end face near the valve shaft, and the ratchet and the coil spring are both located in the mounting groove; a copper sleeve is coaxially fixedly connected in the mounting hole, and the inner circumference of the copper sleeve is used to slide against the outer circumference of the valve stem.

[0018] By adopting the above technical solution, friction loss occurs between the valve stem and the inner wall of the mounting hole during rotation. The copper sleeve reduces this friction, thus minimizing friction loss. Simultaneously, since the fixing block is fixedly connected to the valve body, the probability of needing to replace the valve seat due to wear is reduced, thereby decreasing the material required to manufacture the check valve and lowering the cost of replacing the valve seat.

[0019] Preferably, the rotation direction of the valve stem is the same as the rotation direction of the pawl-driven ratchet.

[0020] By adopting the above technical solution, when the coil spring stores energy, one end of the coil spring is fixedly connected to the valve column and remains stationary, while the other end of the coil spring is driven by the pawl to rotate the ratchet wheel and coil the spring to store energy. When the rotation direction of the valve column is the same as the rotation direction of the ratchet wheel driven by the pawl, the stored energy of the coil spring is gradually released, so that people can rotate the valve column and achieve the effect of saving effort.

[0021] Preferably, the contact surface is a plane, and the sidewall of the protrusion along the circumference of the valve column, except for the contact surface, is an arc surface.

[0022] By adopting the above technical solution, the planar contact surface abuts against the valve disc, thereby improving the stability of the contact surface against the valve disc body. The protrusion, except for the contact surface, is an arc surface, so that when the valve stem rotates, the arc surface abuts against the valve disc, causing the valve disc to slide and thus playing a guiding role.

[0023] Preferably, the valve disc is provided with a first sealing surface, the projection of the first sealing surface along the sliding direction of the valve disc is annular, and the area of ​​the first sealing surface is smaller than the area of ​​the valve disc; the valve seat is provided with a second sealing surface for abutting against the first sealing surface, and the area of ​​the second sealing surface is smaller than the area of ​​the first sealing surface.

[0024] By adopting the above technical solution, the area of ​​the first sealing surface and the second sealing surface is reduced, so as to improve the processing accuracy of the first sealing surface and the second sealing surface, thereby improving the sealing performance and reducing the leakage of mixed fuel when the check valve is not in use, so as to save energy.

[0025] Preferably, a handle is connected to the end of the valve stem opposite to the valve stem, and the length direction of the handle is perpendicular to the axial direction of the valve stem.

[0026] By adopting the above technical solution, people can turn the handle to drive the shaft to rotate, thus saving the labor of maintenance personnel and making maintenance easier.

[0027] In summary, this application includes at least one of the following beneficial technical effects:

[0028] 1. The valve disc is abutted by the contact surface provided by the protrusion, so that maintenance personnel do not need to press the large telescopic spring used in aerospace all the time, thus saving the physical strength of maintenance personnel and making it easier for maintenance personnel to maintain the check valve.

[0029] 2. The elastic potential energy of the telescopic spring is converted to the potential energy of the coil spring, the frictional consumption between the guide block and the fixed block to a certain extent, so as to improve the energy utilization rate and reduce the impact of the valve body on the valve body, thereby improving the service life of the check valve.

[0030] 3. By storing energy through the coil spring, the probability of valve disc and valve seat being damaged due to impact is reduced, thereby saving materials for manufacturing valve disc and valve seat and reducing costs; and without affecting the preload of the extension spring after the valve disc abuts against the valve seat. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this application.

[0032] Figure 2 This is a cross-sectional view of an embodiment of this application.

[0033] Figure 3 yes Figure 2 Enlarged view of point A.

[0034] Figure 4 This is a partial structural diagram of an embodiment of this application.

[0035] Figure 5 yes Figure 4 Enlarged view of point B in the middle.

[0036] Figure 6 yes Figure 2 A magnified view of point C in the middle.

[0037] Figure 7This is a fractured view of an embodiment of this application. Explanation of reference numerals in the attached drawings: 1. Valve seat; 11. Valve body; 111. Inlet; 112. Outlet; 113. Flow chamber; 114. Second sealing surface; 115. Through hole; 116. Annular groove; 12. Fixing block; 121. First limiting hole; 122. Mounting hole; 13. Flow guide; 131. Second limiting hole; 2. Telescopic spring; 3. Valve disc; 31. Disc body; 311. First sealing surface; 32. Valve shaft; 321. Circumferential groove; 4. Valve column; 41. Protrusion; 411. Abutment surface; 42. Handle; 421. Embedded hole; 43. Mounting groove; 44. Auxiliary shaft; 5. Seal; 51. Packing pair; 53. Packing sleeve; 54. Packing pressure plate; 55. Limiting disc; 6. Ratchet; 61. Rotating shaft; 62. Pawl; 7. Coil spring; 8. Return spring; 9. Guide block; 91. Guide surface. Detailed Implementation

[0038] The following is in conjunction with the appendix Figure 1-7 This application will be described in further detail.

[0039] Reference Figure 1 and Figure 2 This application discloses a cryogenic check valve for aerospace applications, comprising a valve seat 1, a telescopic spring 2, and a valve disc 3. Both the valve seat 1 and valve disc 3 are made of cryogenic materials, such as stainless steel 316L or aluminum alloy 5083. The valve seat 1 includes a valve body 11, a fixing block 12, and a flow guide 13. The valve body 11 has an inlet 111, an outlet 112, and a flow chamber 113, which connects the inlet 111 and the outlet 112. The fixing block 12 and the flow guide 13 are both located in the flow chamber 113. The fixing block 12 is closer to the inlet 111 than the flow guide 13, and the flow guide 13 is closer to the outlet 112 than the fixing block 12. The fixing block 12 has a first limiting hole 121, and the flow guide 13 has a second limiting hole 131. The first limiting hole 121 and the second limiting hole 131 are coaxial and pass through the fixing block 12 and the flow guide 13 along their respective axial directions.

[0040] The valve disc 3 includes a disc body 31 and a valve shaft 32. The disc body 31 is annular in projection along the axial direction of the valve shaft 32. The disc body 31 is coaxially sleeved on the outer periphery of the valve shaft 32 and fixedly connected to the valve shaft 32. The two ends of the valve shaft 32 are slidably embedded into the first limiting hole 121 and the second limiting hole 131, respectively. The disc body 31 is located between the fixing block 12 and the flow guide 13. The telescopic spring 2 is coaxially sleeved on the outer periphery of the valve shaft 32, and the two ends of the telescopic spring 2 abut against the surfaces of the disc body 31 and the flow guide 13 facing the disc body 31, respectively. The surface of the disc body 31 near the fixing block 12 has an annular first sealing surface 311, the area of ​​which is smaller than the area of ​​the disc body 31 facing the fixing block 12. The valve body 11 is provided with a second sealing surface 114 for abutting against the first sealing surface 311. The area of ​​the second sealing surface 114 is smaller than that of the first sealing surface 311, so that the first sealing surface 311 and the second sealing surface 114 can be finely machined to improve the sealing performance when the first sealing surface 311 and the second sealing surface 114 abut against each other. The telescopic spring 2 is provided with a preload force that causes the valve body 31 to press against the valve body 11, that is, the preload force of the first sealing surface 311 against the second sealing surface 114. When the first sealing surface 311 is pressed against the second sealing surface 114, the flow cavity 113 is not connected to the inlet 111 and the outlet 112.

[0041] Reference Figure 2 and Figure 3 A cryogenic check valve for aerospace applications also includes a valve stem 4 and a sealing element 5. The valve body 11 has a through hole 115, the axis of which is perpendicular to and coplanar with the axis of the valve shaft 32. The valve stem 4 is rotatably fitted into the through hole 115, with one end of the valve stem 4 extending into the flow chamber 113 and fixedly connected to a protrusion 41. The other end of the valve stem 4 extends out of the through hole 115 and is fixedly connected to a handle 42. The length direction of the handle 42 is perpendicular to the axial direction of the valve stem 4, so that the valve stem 4 can be rotated by turning the handle 42. The protrusion 41 has an abutment surface 411, which is flat and is used to abut against the valve body 31. When the abutment surface 411 abuts against the valve body 31, the flow chamber 113 connects the inlet 111 and the outlet 112. When maintenance personnel repair the check valve, they make the contact surface 411 abut against the valve body 31 to facilitate the inspection and repair of the first sealing surface 311 and the second sealing surface 114, thereby improving maintenance efficiency. Except for the contact surface 41, the side wall of the protrusion 41 along the circumference of the valve stem 4 is an arc surface, which facilitates the sliding of the protrusion 41 when it slides against the valve body 31.

[0042] The sealing element 5 includes a packing assembly 51, two O-rings, a packing sleeve 53, a packing pressure plate 54, and a limiting disc 55. A through hole 115 has a coaxial annular groove 116 near the handle 42. The packing assembly 51 fills the annular groove 116. The packing sleeve 53 is coaxially fitted around the valve stem 4 and used to compress the packing assembly 51. The inner and outer circumferences of the packing sleeve 53 are coaxially provided for the two O-rings to be embedded in the inner and outer annular grooves, respectively. The packing pressure plate 54 is annular and coaxially fitted around the valve stem 4, abutting against the packing sleeve 53. A limiting disc 55 is coaxially sleeved around the outer periphery of the valve stem 4 and abuts against the packing pressure plate 54. The limiting disc 55 is fixedly connected to the valve body 11 by bolts, and the limiting disc 55 presses the packing pair 51 under the action of the bolts. At the same time, a friction pair is formed between the packing pair 51, the O-ring, and the valve stem 4. The friction pair allows the valve stem 4 to remain stationary or rotate within the through hole 115. When the handle 42 applies sufficient force to overcome the static friction and convert it into dynamic friction, the handle 42 causes the valve stem 4 to start rotating. One end of the handle 42 is provided with a recess 421, in which the valve stem 4 is embedded, and the valve stem 4 is interference-fitted to the inner wall of the recess 421. A baffle is connected to the end face of the valve stem 4. The diameter of the baffle is larger than the diameter of the valve stem 4. A bolt passes through the baffle and is threaded into the threaded hole to press the handle 42 through the baffle.

[0043] Reference Figure 4 , Figure 5 and Figure 6 A cryogenic check valve for aerospace applications also includes a ratchet 6 and a coil spring 7. A fixing block 12 has a mounting hole 122 communicating with a first limiting hole 121, and the mounting hole 122 is coaxial with the valve stem 4. A copper sleeve is coaxially fixedly embedded in the mounting hole 122. One end of the valve stem 4 near the valve shaft 32 is rotatably embedded in the copper sleeve, and the inner circumference of the copper sleeve is used to slide against the valve stem 4. A mounting groove 43 is coaxially provided on the surface of the valve stem 4 near the valve shaft 32, and both the ratchet 6 and the coil spring 7 are located within the mounting groove 43. A pressure-bearing groove is coaxially provided at the bottom of the mounting groove 43, and a bearing is embedded in the pressure-bearing groove. A rotating shaft 61 is embedded in the inner circumference of the bearing. An auxiliary shaft 44 is fixedly connected to the bottom of the mounting groove 43. One end of the coil spring 7 is fixedly connected to the rotating shaft 61, and the other end of the coil spring 7 is fixedly connected to the auxiliary shaft 44.

[0044] Reference Figure 5 and Figure 7The valve shaft 32 is provided with multiple clearance grooves 321 along its own axial direction. All clearance grooves 321 are embedded with a return spring 8. All return springs 8 are connected to guide blocks 9. All guide blocks 9 are provided with guide surfaces 91 on two surfaces along the axial direction of the valve shaft 32. The two guide surfaces 91 on the same guide block 9 gradually approach each other as they move away from the valve shaft 32. The guide surfaces 91 are used to slide against the fixing block 12. When the valve shaft 32 slides and compresses the telescopic spring 2, the guide surface 91 is compressed into the clearance groove 321 by sliding against the fixing block 12. As the valve shaft 32 continues to slide, the guide block 9 slides against the inner wall of the first limiting hole 121. Finally, the guide block 9 bounces into the mounting groove 43 based on the return spring 8. When the telescopic spring 2 causes the valve shaft 32 to return to its original position, the other guide surface 91 of the guide block 9 in the mounting groove 43 is compressed into the clearance groove 321 by sliding against the fixing block 12. As the valve shaft 32 continues to return to its original position, the guide block 9 slides against the inner wall of the first limiting hole 121 until the guide block 9 disengages from the mounting groove 43.

[0045] The guide block 9 is hinged with a pawl 62. When the valve shaft 32 slides away from the flow guide shroud 13, causing the telescopic spring 2 to return to its original position, the pawl 62 engages with the ratchet 6 and drives the ratchet 6 to rotate. The rotating shaft 61 drives the coil spring 7 to rotate so that the coil spring 7 can store energy, and the clearance groove 321 is used for the pawl 62 to slide into. All hinge shafts are fitted with torsion springs on their outer circumferences, and the two ends of the torsion springs abut against the guide block 9 and the pawl 62 respectively.

[0046] When the valve shaft 32 slides and compresses the telescopic spring 2, the pawl 62 in the clearance groove 321 is squeezed by the ratchet 6 and rotates around the hinge axis, squeezing the torsion spring. At the same time, due to the gap between the clearance groove 321 and the guide block 9, when the valve shaft 32 moves, the ratchet 6 rotates based on the elastic force generated by the return of the coil spring 7, so that the potential energy stored in the coil spring 7 can be released, so that when the valve shaft 32 slides in a direction away from the guide shield 13, the coil spring 7 can store energy, thereby avoiding the coil spring 7 from over-coiling and failing.

[0047] The implementation principle of a cryogenic check valve for aerospace applications according to this application embodiment is as follows: When inspecting the check valve, the valve body 31 is abutted by the flat contact surface 411 of the protrusion 41 to improve the stability of the valve body 31. At this time, the valve body 31 is disengaged from the valve body 11 to facilitate the inspection of the check valve. Simultaneously, during the operation of the check valve, when the valve shaft 32 slides away from the guide shield 13 and the telescopic spring 2 returns to its original position, the pawl 62 causes the ratchet 6 to rotate and the coil spring 7 to coil and store energy. However, when the valve shaft 32 returns to its original position based on the elastic force of the telescopic spring 2 until the check valve closes, the elastic potential energy of the telescopic spring 2 is gradually converted into the potential energy of the coil spring 7 and the frictional loss between the guide block 9 and the fixed block 12. The reduced tension of the telescopic spring 2 causes the valve body 31 to abut against the valve body 11. After the valve body 31 abuts against the valve body 11, the ratchet 6 stops rotating. One end of the coil spring 7 is fixed to the ratchet 6 by the pawl 62, while the other end is fixedly connected to the auxiliary shaft 44, maintaining the coil spring 7 in a compressed state. After the valve body 31 abuts against the valve body 11, the check valve is closed, and the valve shaft 32 does not slide, thus not affecting the preload of the telescopic spring 2 on the valve body 31, thereby improving energy efficiency. During maintenance, the valve stem 4 is rotated in the same direction as when the pawl 62 drives the ratchet 6. The elastic potential energy of the coil spring 7 can also be used to rotate the valve stem 4, saving the maintenance personnel's energy and facilitating subsequent maintenance of the check valve.

[0048] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A cryogenic check valve for aerospace applications, comprising a valve seat (1), a telescopic spring (2), and a valve disc (3) slidably connected to the valve seat (1), wherein the valve seat (1) has an inlet (111), an outlet (112), and a flow chamber (113), the flow chamber (113) being used to connect the inlet (111) and the outlet (112), the telescopic spring (2) being disposed between the valve seat (1) and the valve disc (3), the telescopic spring (2) having a preload force that causes the valve disc (3) to press against the valve seat (1), wherein when the valve disc (3) presses against the valve seat (1), the flow chamber (113) is not connected to the inlet (111) and the outlet (112), characterized in that: It also includes a valve stem (4) and a seal (5). The valve seat (1) is provided with a through hole (115). The axis of the through hole (115) is perpendicular to the sliding direction of the valve disc (3). The valve stem (4) is coaxially rotatably embedded in the through hole (115). One end of the valve stem (4) extends into the flow cavity (113) and is fixedly connected to a protrusion (41). The other end of the valve stem (4) extends out of the through hole (115). The protrusion (41) is located away from the valve disc (3). On one side of the compression spring (2), the surface of the protrusion (41) away from the axis of the valve stem (4) is provided with an abutment surface (411) for abutting the valve disc (3). When the abutment surface (411) abuts the valve disc (3), the flow cavity (113) connects the inlet (111) and the outlet (112); the sealing element (5) is connected between the valve body (11) and the valve stem (4) and seals, and the contact surfaces of the sealing element (5) and the valve stem (4) form a friction pair; The valve seat (1) includes a valve body (11), a fixing block (12), and a flow guide (13). The inlet (111), outlet (112), and flow chamber (113) are located on the valve body (11). The fixing block (12) and the flow guide (13) are both fixedly connected to the valve body (11) and located in the flow chamber (113). The fixing block (12) is provided with a first limiting hole (121), and the flow guide (13) is provided with a coaxial hole at the first limiting hole (121). The second limiting hole (131) of the limiting hole (121); the valve disc (3) includes a disc body (31) and a valve shaft (32), the valve shaft (32) is coaxially slidably embedded in the first limiting hole (121) and the second limiting hole (131), the disc body (31) is fixedly connected to the outer periphery of the valve shaft (32), the disc body (31) is located between the fixing block (12) and the flow guide (13), and the abutting surface (411) is used to abut the disc body (31). It also includes a ratchet (6) and a coil spring (7). The fixing block (12) is provided with a mounting hole (122) that connects to the first limiting hole (121). The valve stem (4) is rotatably embedded in the mounting hole (122). The ratchet (6) is coaxially rotatably connected to the surface of the valve stem (4) near the valve shaft (32) by a rotating shaft (61). One end of the coil spring (7) is fixedly connected to the rotating shaft (61), and the other end of the coil spring (7) is fixedly connected to the valve stem (4). The valve shaft (32) is provided with a plurality of clearance grooves (321) along its own axial direction. A return spring (8) is embedded in all the clearance grooves (321). All the return springs (8) are connected to guide blocks (9). Guide surfaces (91) are provided on two surfaces along the axial direction of the valve shaft (32). The two guide surfaces (91) on the same guide block (9) gradually approach each other as they move away from the valve shaft (32). The guide surfaces (91) are used to slide against the fixed block (12). The guide block (9) is hinged to a pawl (62) by a hinge shaft. The clearance groove (321) is used for the pawl (62) to be inserted. When the valve shaft (32) slides in a direction away from the flow guide (13), the pawl (62) is used to drive the ratchet (6) to rotate.

2. The cryogenic check valve for aerospace applications according to claim 1, characterized in that: A torsion spring is fitted around the outer periphery of the hinge shaft, and the two ends of the torsion spring abut against the pawl (62) and the guide block (9) respectively.

3. The cryogenic check valve for aerospace applications according to claim 1, characterized in that: The valve stem (4) is provided with a mounting groove (43) on the end face near the valve shaft (32), and the ratchet (6) and the coil spring (7) are both located in the mounting groove (43); a copper sleeve is coaxially fixedly connected in the mounting hole (122), and the inner circumference of the copper sleeve is used to slide against the outer circumference of the valve stem (4).

4. The cryogenic check valve for aerospace applications according to claim 1, characterized in that: The rotation direction of the valve stem (4) is the same as the rotation direction of the ratchet (6) driven by the pawl (62).

5. A cryogenic check valve for aerospace applications according to claim 1, characterized in that: The contact surface (411) is a plane, and the side wall of the protrusion (41) along the circumference of the valve column (4) is an arc surface except for the contact surface (411).

6. The cryogenic check valve for aerospace applications according to claim 1, characterized in that: The valve disc (3) is provided with a first sealing surface (311), the projection of the first sealing surface (311) along the sliding direction of the valve disc (3) is annular, and the area of ​​the first sealing surface (311) is smaller than the area of ​​the valve disc (3); the valve seat (1) is provided with a second sealing surface (114) for abutting the first sealing surface (311), and the area of ​​the second sealing surface (114) is smaller than the area of ​​the first sealing surface (311).

7. A cryogenic check valve for aerospace applications according to claim 1, characterized in that: The valve stem (4) is connected to a handle (42) at one end away from the valve stem (4), and the length direction of the handle (42) is perpendicular to the axial direction of the valve stem (4).

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