Rotary sealing structure of high-speed input shaft of low-temperature end face sealing tester

Abstract

According to the high-speed input shaft rotary sealing structure of the low-temperature end face sealing tester, two elastic sealing rings are arranged between a transparent cover and an input shaft in the axial direction, the two sealing rings are separated through a distance ring to form an air cavity, and when high-pressure air is introduced into the air cavity, the high-pressure air can eject lips of the two sealing rings open, so that the sealing performance of the high-speed input shaft is improved. Along with the flowing of high-pressure gas, a high-pressure sealing gas film is formed between the two sealing rings and the input shaft, and the high-pressure sealing gas film is used for supporting lips of the sealing rings, so that the sealing rings and the input shaft are in a non-contact state, and the friction of the input shaft of the tester to the lips of the sealing rings during high-speed rotation is avoided; the flow of the gas can take away heat generated by the lip part of the sealing ring, the service life of the sealing ring is prolonged, the radial run-out of the input shaft can be contained by the combined action of the elastic deformation of the sealing ring and the high-pressure sealing gas film, the precision requirements of the tester on parts and assembly are reduced, and the sealing performance between the input shaft and the transparent cover is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of aerospace cryogenic liquid rocket engine tests, in particular to a rotary seal structure for a high-speed input shaft of a cryogenic end face seal tester. Background Art

[0002] At present, during the development of liquid oxygen-kerosene rocket engines, a cryogenic end face seal tester is used to test the cryogenic end face seal in the turbopump to verify its working reliability. The structure of the existing cryogenic end face seal tester is as Figure 1 shown. A double-labyrinth seal structure is designed between the input shaft and the through cover. By introducing high-pressure nitrogen gas into the center of the double-labyrinth seal, a high-pressure gas cavity is formed between the input shaft and the through cover to block the leakage of the test medium inside the tester. However, this seal structure has the following defects during use:

[0003] 1) When designing the clearance between the input shaft of the tester and the inner hole of the labyrinth seal, it is strictly controlled to ensure that the gas pressure in the double-labyrinth gas cavity is higher than the pressure of the test medium. Nevertheless, when the chamber pressure of the tester is high, the leakage at the double-labyrinth seal is still very serious, and the leakage of the test medium is not completely blocked;

[0004] 2) When the tester runs at high speed, the input shaft and the inner hole of the labyrinth seal are prone to rubbing;

[0005] 3) The requirements for the machining and assembly accuracy are particularly high.

[0006] It is necessary to improve the existing technology. Content of the Utility Model

[0007] The technical problem to be solved by the utility model is to provide a rotary seal structure for a high-speed input shaft of a cryogenic end face seal tester with a reasonable structure, which can avoid the leakage problem of the test medium and at the same time reduce the requirements for machining and assembly accuracy.

[0008] To solve the above technical problem, the technical solution adopted by the utility model is: a rotary seal structure for a high-speed input shaft of a cryogenic end face seal tester, including a through cover and an input shaft. The through cover is provided with an input shaft hole, and the input shaft rotatably passes through the input shaft hole. A seal assembly is provided between the through cover and the input shaft. The seal assembly includes a first sealing ring, a spacer ring, and a second sealing ring arranged in sequence along the axial direction. An air cavity is formed between the first sealing ring, the spacer ring, the second sealing ring, and the input shaft. The through cover is provided with an air inlet and a vent hole. The vent hole is arranged on the hole wall of the input shaft hole. The air inlet is communicated with the vent hole through an air delivery channel. The vent hole is correspondingly arranged with the spacer ring. The spacer ring is provided with a plurality of through holes radially penetrating the spacer ring. The vent hole is communicated with the air cavity through the through holes;

[0009] When supplying high-pressure gas to the air inlet, the high-pressure gas sequentially passes through the gas transmission channel, the ventilation port, and the through hole of the distance ring and enters the gas cavity, and leaks out between the first sealing ring and the input shaft to form a first high-pressure sealing gas film to support the first sealing ring; and leaks out between the second sealing ring and the input shaft to form a second high-pressure sealing gas film to support the second sealing ring.

[0010] Furthermore, the first sealing ring is provided with a first lip, and a first spring is arranged in the first lip; the second sealing ring is provided with a second lip, and a second spring is arranged in the second lip, and the opening directions of the first lip and the second lip are opposite.

[0011] Furthermore, a first abutting ring is arranged on one side of the first sealing ring close to the input shaft; a second abutting ring is arranged on one side of the second sealing ring close to the input shaft.

[0012] Furthermore, the cross-sections of the first abutting ring and the second abutting ring are both triangular.

[0013] Furthermore, a first annular clamping groove is arranged on the inner side of the first lip; a second annular clamping groove is arranged on the inner side of the second lip.

[0014] Furthermore, a through hole groove is arranged on the outer side of the distance ring, and the through hole is arranged at the bottom of the through hole groove.

[0015] Furthermore, the distance ring is in close fit with the input shaft hole.

[0016] Furthermore, a limiting convex ring is arranged at one end of the input shaft hole of the transparent cover.

[0017] Furthermore, it further includes a retaining ring, the retaining ring is fixed to the end of the input shaft hole far from the limiting convex ring by screws, and a sealing component limiting groove is formed between the retaining ring and the limiting convex ring.

[0018] Furthermore, both the first sealing ring and the second sealing ring are made of rubber material with low-temperature resistance and toughness.

[0019] The beneficial effects of the utility model are as follows: it provides a high-speed input shaft rotating sealing structure of a low-temperature end face sealing tester, comprising a transparent cover and an input shaft, two elastic sealing rings are axially arranged between the transparent cover and the input shaft, the two sealing rings are separated by a distance ring with holes, an air cavity is formed between the two sealing rings, when high-pressure gas is introduced into the air cavity, the high-pressure gas can push open the lips of the two sealing rings, with the flow of high-pressure gas, a high-pressure sealing air film is formed between the two sealing rings and the input shaft, the high-pressure sealing air film is used to support the lips of the sealing rings, so that the sealing rings and the input shaft are in a non-contact state, thereby avoiding damage to the lips of the sealing rings when the input shaft of the tester rotates at a high speed. Friction, at the same time, the flow of gas can also take away the heat generated by the lip of the sealing ring, extending the service life of the sealing ring. At the same time, since the sealing ring is made of low-temperature resistant rubber material with certain elasticity, the radial runout of the input shaft can be accommodated by the elastic deformation of the sealing ring and the high-pressure sealing air film, avoiding the occurrence of scratches between the labyrinth seal and the input shaft in the past, reducing the requirements of the tester on part accuracy and assembly accuracy, and by adjusting the pressure of the gas in the air cavity, the dynamic pressure generated by the flow of the high-pressure sealing air film is higher than the pressure of the sealed test medium, thereby realizing the sealing of the test medium between the transparent cover and the input shaft, and effectively ensuring the sealing performance between the input shaft and the transparent cover. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The specific structure of the utility model is described in detail below with reference to the accompanying drawings:

[0021] Figure 1 It is a schematic diagram of the overall cross-sectional structure of a low-temperature end face sealing tester in the prior art;

[0022] Figure 2 It is a schematic diagram of the overall cross-sectional structure of the high-speed input shaft rotary seal structure of the low-temperature end face seal tester of the utility model;

[0023] Figure 3 for Figure 2 A close-up structural diagram of part A in the middle;

[0024] Figure 4 It is a cross-sectional structural schematic diagram of a transparent cover of a high-speed input shaft rotary seal structure of a low-temperature end face seal tester of the utility model;

[0025] Figure 5 It is a cross-sectional structural schematic diagram of a sealing component of a high-speed input shaft rotary sealing structure of a low-temperature end face sealing tester of the utility model;

[0026] 1-transparent cover; 11-input shaft hole; 12-air inlet; 13-air transmission channel; 14-exhaust port; 15-limiting convex ring; 16-blocking ring; 17-screw;

[0027] 2- Input shaft;

[0028] 3 - Sealing assembly;

[0029] 31 - First sealing ring; 311 - First lip; 312 - First spring; 313 - First abutting ring; 314 - First annular groove;

[0030] 32 - Spacer ring; 321 - Through hole; 322 - Through hole groove;

[0031] 33 - Second sealing ring; 331 - Second lip; 332 - Second spring; 333 - Second abutting ring; 334 - Second annular groove;

[0032] 34 - Air cavity;

[0033] 4 - Tester; 41 - Collection cavity. Detailed implementation mode

[0034] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0035] In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present utility model.

[0036] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more features. In the description of the present utility model, "a plurality" means two or more, unless otherwise specifically defined.

[0037] In the present utility model, unless otherwise clearly defined or limited, terms such as "installed", "connected", "joined", "fixed", etc. shall be understood in a broad sense. For example, it can be a connection, a detachable connection, or an integral body; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0038] In the present utility model, unless otherwise clearly defined or limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features between them. Moreover, the first feature being "above", "over", and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "under", and "beneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.

[0039] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic descriptions of the above terms should not be understood as necessarily referring to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine the different embodiments or examples described in this specification.

[0040] Embodiment

[0041] Please refer to Figures 2 to 5, this embodiment provides a high-speed input shaft rotary seal structure for a low-temperature end face seal tester, including a through cover 1 and an input shaft 2. The through cover 1 is provided with an input shaft hole 11, and the input shaft 2 rotatably passes through the input shaft hole 11. A seal assembly 3 is provided between the through cover 1 and the input shaft 2. The seal assembly 3 includes a first sealing ring 31, a spacer ring 32, and a second sealing ring 33 arranged in sequence along the axial direction. An air cavity 34 is formed between the first sealing ring 31, the spacer ring 32, the second sealing ring 33, and the input shaft 2. The through cover 1 is provided with an air inlet 12 and a vent hole. The vent hole is arranged on the hole wall of the input shaft hole 11. The air inlet 12 is communicated with the vent hole through an air delivery channel 13. The vent hole is correspondingly arranged with the spacer ring 32. The spacer ring 32 is provided with a plurality of through holes 321 penetrating the spacer ring 32 along the radial direction. The vent hole is communicated with the air cavity 34 through the through holes 321;

[0042] When high-pressure gas is supplied to the air inlet 12, the high-pressure gas sequentially passes through the air delivery channel 13, the vent hole, and the through holes 321 of the spacer ring 32 to enter the air cavity 34, forming a high-pressure air chamber, and leaks out between the first sealing ring 31 and the input shaft 2 to form a first high-pressure sealing air film to support the first sealing ring; it leaks out between the second sealing ring 33 and the input shaft 2 to form a second high-pressure sealing air film to support the second sealing ring.

[0043] In this embodiment, the through cover 1 covers one end of the tester 4 where the input shaft 2 is provided. A collection cavity 41 is formed between the end face of the tester 4 and the through cover 1. The input shaft 2 of the tester 4 passes out of the through cover 1 from the input shaft hole 11 of the through cover 1 to the outside. In order to prevent the test medium in the tester 4 from leaking to the outside through the gap between the input shaft hole 11 of the through cover 1 and the input shaft 2, a seal assembly 3 is arranged between the input shaft hole 11 of the through cover 1 and the input shaft 2. The seal assembly 3 specifically includes a first sealing ring 31, a spacer ring 32, and a second sealing ring 33 arranged in sequence along the axial direction. When the input shaft 2 is static, the outer sides of both the first sealing ring 31 and the second sealing ring 33 are in contact with the hole wall of the input shaft hole 11 of the through cover 1, and the inner sides of both the first sealing ring 31 and the second sealing ring 33 are in contact with the input shaft 2. The spacer ring 32 is used to separate the first sealing ring 31 and the second sealing ring 33 in the axial direction, and an air cavity 34 is formed between the first sealing ring 31, the second sealing ring 33, and the input shaft 2.

[0044] The through cover 1 is provided with an air inlet 12, a vent hole, and an exhaust port 14. The vent hole is arranged on the hole wall of the input shaft hole 11. The air inlet 12 is communicated with the vent hole through an air delivery channel 13 arranged inside the through cover 1. The exhaust port 14 is communicated with the collection cavity 41 between the tester 4 and the through cover 1. The spacer ring 32 is evenly provided with a plurality of through holes 321 penetrating the spacer ring along the circumferential surface. The vent hole is communicated with the air cavity 34 through the through holes 321.

[0045] When the input shaft rotates at a low speed of less than 5000 r / min, the first sealing ring 31 and the second sealing ring 33 both hold the input shaft 2 tightly.

[0046] Before the input shaft 2 needs to be driven to rotate at high speed, high-pressure gas is introduced into the air inlet 12. The high-pressure gas enters the air cavity 34 through the air delivery channel 13, the air vent and the through hole 321 of the distance ring 32 of the transparent cover 1 in sequence to form a high-pressure gas chamber. The high-pressure gas opens the first sealing ring 31, pushes the first sealing ring 31 away from the input shaft 2, and leaks out between the first sealing ring 31 and the input shaft 2 to the collecting cavity 41 to form a first high-pressure sealing gas film to support the first sealing ring 31. The dynamic pressure generated by the flow of the first high-pressure sealing gas film is higher than the pressure of the sealed test medium. The high-pressure gas entering the collecting cavity 41 can be discharged together with the test medium from the exhaust port 14; at the same time, the high-pressure gas opens the second sealing ring 33, pushes the second sealing ring 33 away from the input shaft 2, pushes it away from the input shaft 2, and leaks out between the second sealing ring 33 and the input shaft 2 to the outside to form a second high-pressure sealing gas film to support the second sealing ring 33.

[0047] This ensures that the first sealing ring 31 and the input shaft 2, as well as the second sealing ring 33 and the input shaft 2 are in a non-contact state, thereby avoiding wear of the first sealing ring 31 and the second sealing ring 33 caused by friction when the input shaft 2 rotates. Since the pressure of the high-pressure gas is greater than the pressure of the test medium, it can effectively prevent the test medium from leaking from between the transparent cover 1 and the input shaft 2.

[0048] The gas pressure in the air cavity 34 can be adjusted so that the dynamic pressure generated by the flow of the high-pressure sealing gas film is higher than the pressure of the sealed test medium, thereby achieving sealing of the test medium between the transparent cover 1 and the input shaft 2 and effectively ensuring the sealing performance between the input shaft and the transparent cover.

[0049] At the same time, since a high-pressure sealing air film is used to seal the transparent cover 1 and the input shaft 2, the radial runout of the input shaft 2 during rotation will not affect the sealing performance, effectively reducing the tester's requirements for part accuracy and assembly accuracy.

[0050] In this embodiment, the high-pressure gas is preferably nitrogen, and the test medium is liquid nitrogen.

[0051] In one embodiment, the structures of the first sealing ring 31 and the second sealing ring 33 are improved to ensure the sealing effect of the first sealing ring 31 and the second sealing ring 33. Specifically, the first sealing ring 31 is provided with a first lip 311, and a first spring 312 is provided in the first lip 311; the second sealing ring 33 is provided with a second lip 331, and a second spring 332 is provided in the second lip 331, and the opening directions of the first lip 311 and the second lip 331 are opposite.

[0052] In this embodiment, in order to ensure that the first sealing ring 31 and the second sealing ring 33 have sufficient clamping force on the input shaft 2 and can also be easily pushed away from the input shaft 2 by the high-pressure gas, the first sealing ring 31 is provided with a first lip 311, the opening direction of the first lip 311 is toward one end of the tester, and a first spring 312 is provided in the first lip 311. The first spring 312 with different elastic force specifications can be replaced according to design requirements, thereby changing the clamping force of the first sealing ring 31 on the input shaft 2. When high-pressure gas is supplied to the air cavity 34 between the first sealing ring 31 and the second sealing ring 33, the high-pressure gas can more easily compress the first sealing ring 31 in the radial direction, so that the high-pressure gas is pushed away from the first sealing ring 31 and the input shaft 2. The second lip 331 is provided with a second spring 332, and the second spring 332 with different elastic force specifications can be replaced according to design requirements, so as to change the clamping force of the second sealing ring 33 on the input shaft 2. When high-pressure gas is supplied to the air cavity 34 between the first sealing ring 31 and the second sealing ring 33, the high-pressure gas can more easily compress the second sealing ring 33 in the radial direction, so that the high-pressure gas leaks from between the second sealing ring 33 and the input shaft 2 to the outside, forming a second high-pressure sealing air film, which effectively prevents the entry of foreign matter.

[0053] In order to ensure the reliability of the first spring 312 and the second spring 332, the first spring 312 and the second spring 332 are preferably made of low-temperature resistant 304 stainless spring steel. The first spring 312 and the second spring 332 can be leaf springs with a U-shaped cross section or can be coil springs.

[0054] The elastic forces of the two springs need to be set separately according to the pressure of the test medium. Under the pressure of the test medium, the high-pressure gas in the air cavity can simultaneously open the lips of the two sealing rings.

[0055] In order to ensure the sealing effect, the first lip 311 of the first sealing ring 31 is arranged to face the collecting chamber 41. Under the pressure of the test medium, the inner and outer sides of the first sealing ring 31 are tightly pressed against the surfaces of the input shaft 2 and the transparent cover 1 respectively, and when the input shaft 2 is in a static state, the sealing effect on the test medium is ensured; the second lip 331 of the second sealing ring 33 is arranged to face the outside. Under the action of atmospheric pressure, the inner and outer sides of the second sealing ring 33 are pressed against the surfaces of the input shaft 2 and the transparent cover 1 respectively, and when the input shaft 2 is in a static state, a double sealing effect can be provided.

[0056] In order to ensure the wear resistance of the first sealing ring and the second sealing ring, a wear-resistant coating is provided on the first sealing ring and the second sealing ring. The wear-resistant coating is preferably a graphite coating or a ceramic coating.

[0057] Preferably, both the first sealing ring 31 and the second sealing ring 33 are PTFE seals.

[0058] In one embodiment, the structures of the first sealing ring 31 and the second sealing ring 33 are improved to facilitate the high-pressure gas to push the first sealing ring 31 or the second sealing ring 33 away from the input shaft 2. Specifically, a first abutting ring 313 is provided on one side of the first sealing ring 31 close to the input shaft 2; a second abutting ring 333 is provided on one side of the second sealing ring 33 close to the input shaft 2.

[0059] In this embodiment, by providing the first abutting ring 313 on one side of the first sealing ring 31 near the input shaft 2 at one end of the first lip 311, the first abutting ring 313 abuts against the input shaft 2, and a gap is left between the end of the first sealing ring 31 close to the second sealing ring 33 and the input shaft 2, thereby ensuring the sealing effect between the transparent cover 1 and the input shaft 2 when the input shaft 2 is static. When high-pressure gas is introduced between the first sealing ring 31 and the second sealing ring 33, the high-pressure gas can more easily push the first abutting ring 313 away from the input shaft 2;

[0060] By providing the second abutting ring 333 on one side of the second sealing ring 33 near the input shaft 2 at one end of the second lip 331, the second abutting ring 333 abuts against the input shaft 2, and a gap is left between the end of the second sealing ring 33 close to the first sealing ring 31 and the input shaft 2, thereby ensuring the sealing effect between the transparent cover 1 and the input shaft 2 when the input shaft 2 is static. When high-pressure gas is introduced between the first sealing ring 31 and the second sealing ring 33, the high-pressure gas can more easily push the second abutting ring 333 away from the input shaft 2.

[0061] Preferably, the cross-sections of the first abutting ring 313 and the second abutting ring 333 are both triangular. By abutting against the input shaft 2 with the apex angles of the triangular abutting rings, the contact sealing effect can be well ensured. At the same time, the sides of the triangular abutting rings are also more easily pushed away from the input shaft 2 by the external force applied by the high-pressure gas.

[0062] In one embodiment, the structures of the first sealing ring 31 and the second sealing ring 33 are improved to ensure that a first annular slot 314 is provided inside the first lip 311; a second annular slot 334 is provided inside the second lip 331.

[0063] In this embodiment, the first spring 312 is installed in the first lip 311. To prevent the first spring 312 from disengaging from the first lip 311, a first annular clamping groove 314 is provided on the inner side of the first lip 311. The first spring 312 is disposed in the first annular clamping groove 314, and the first spring 312 is limited by the groove wall of the first annular clamping groove 314, so as to ensure that the first spring 312 can be stably and reliably fixed in the first lip 311. Similarly, a second annular clamping groove 334 is provided on the inner side of the second lip 331, and the second spring 332 is disposed in the second annular clamping groove 334. The second spring 332 is limited by the groove wall of the second annular clamping groove 334, so as to ensure that the second spring 332 can be stably and reliably fixed in the second lip 331.

[0064] In one embodiment, the structure of the spacer ring 32 is improved to ensure uniform intake of air into the air chamber 34. Specifically, a through-hole groove 322 is provided on the outer side of the spacer ring 32, and the through-hole 321 is provided at the bottom of the through-hole groove 322.

[0065] In this embodiment, in order to enable the high-pressure gas to enter the inner side of the spacer ring 32 more uniformly from the outer side of the spacer ring 32, a through-hole groove 322 is provided on the outer side of the spacer ring 32 along the circumferential surface of the spacer ring. A plurality of through-holes 321 are uniformly arranged along the circumferential direction at the bottom of the through-hole groove 322. When the spacer ring 32 is installed in place, the notch of the through-hole groove 322 is aligned with the air vent of the transparent cover 1, and the high-pressure gas enters the through-hole groove 322 from the air vent, and then enters the inner side of the spacer ring 32 through the plurality of through-holes 321 in the through-hole groove 322, thereby ensuring uniform intake of air into the air chamber 34.

[0066] In one embodiment, the structure of the spacer ring 32 is improved to ensure the airtightness between the spacer ring 32 and the transparent cover 1. Specifically, the spacer ring 32 is in close fit with the input shaft hole 11 of the transparent cover 1.

[0067] In this embodiment, in order to prevent the high-pressure gas from leaking between the first sealing ring 31 and the transparent cover 1 or between the second sealing ring 33 and the transparent cover 1, the spacer ring 32 is in close fit with the transparent cover 1, which can effectively prevent the high-pressure gas from leaking between the first sealing ring 31 and the transparent cover 1 or between the second sealing ring 33 and the transparent cover 1 through the outer side of the spacer ring 32, thereby ensuring the sealing performance.

[0068] In one embodiment, the structure of the transparent cover 1 is improved to facilitate the installation of the sealing assembly 3. Specifically, a limiting convex ring 15 is provided at one end of the input shaft hole 11 of the transparent cover 1.

[0069] In this embodiment, a limiting convex ring 15 is provided at one end of the input shaft hole 11 of the transparent cover 1 close to the tester 4. The sealing assembly 3 is inserted from the end of the input shaft hole 11 of the transparent cover 1 away from the tester 4. Restricted by the limiting convex ring 15, the sealing assembly 3 can be installed in place, so that the through hole of the positioning ring 32 of the sealing assembly 3 communicates with the air vent of the input shaft hole 11.

[0070] For the convenience of fixing the sealing assembly 3 and facilitating later maintenance, a retaining ring 16 is further included. The retaining ring 16 is fixed to the end of the input shaft hole 11 away from the limiting convex ring 15 by a screw 17. A sealing assembly limiting groove is formed between the retaining ring 16 and the limiting convex ring 15.

[0071] The retaining ring 16 includes a fixing part and a limiting part. The diameter of the fixing part is larger than the aperture of the input shaft hole 11, and the outer diameter of the limiting part is adapted to the aperture of the input shaft hole 11. When the limiting part is inserted into the input shaft hole 11 and installed in place, the limiting part abuts against the second sealing ring 33. At this time, the fixing part can be fixed to the end face of the transparent cover 1 by the screw 17, which is very convenient.

[0072] In one embodiment, the materials of the first sealing ring 31 and the second sealing ring 33 are improved to ensure that the first sealing ring 31 and the second sealing ring 33 can meet the low-temperature working conditions. Specifically, the first sealing ring 31 and the second sealing ring 33 are both made of a rubber material with low-temperature resistance and toughness.

[0073] In this embodiment, the first sealing ring 31 and the second sealing ring 33 made of a synthetic rubber material with low-temperature resistance and toughness can meet the test working conditions of the high-speed input shaft rotating seal structure of the low-temperature end face seal tester in a low-temperature test environment.

[0074] The first sealing ring 31 and the second sealing ring 33 are preferably made of flexible rubber materials such as fluororubber, polyimide rubber, and modified silicone rubber.

[0075] From the above description, it can be seen that the beneficial effects of the utility model are: it provides a high-speed input shaft rotating sealing structure of a low-temperature end face sealing tester, including a transparent cover and an input shaft, two elastic sealing rings are axially arranged between the transparent cover and the input shaft, and the two sealing rings are separated by a spacing ring with holes, and an air cavity is formed between the two sealing rings. When high-pressure gas is introduced into the air cavity, the high-pressure gas can push open the lips of the two sealing rings, and as the high-pressure gas flows, a high-pressure sealing air film is formed between the two sealing rings and the input shaft, and the high-pressure sealing air film is used to support the lips of the sealing rings, so that the sealing rings and the input shaft are in a non-contact state, thereby avoiding the seal when the input shaft of the tester rotates at a high speed. The friction of the lip of the ring, and the flow of gas can also take away the heat generated by the lip of the sealing ring, extending the service life of the sealing ring. At the same time, since the sealing ring is made of low-temperature resistant rubber material with certain elasticity, the radial runout of the input shaft can be accommodated by the elastic deformation of the sealing ring and the high-pressure sealing air film, avoiding the occurrence of scratches between the labyrinth seal and the input shaft in the past, reducing the requirements of the tester on part accuracy and assembly accuracy, and by adjusting the pressure of the gas in the air cavity, the dynamic pressure generated by the flow of the high-pressure sealing air film is higher than the pressure of the sealed test medium, thereby realizing the sealing of the test medium between the transparent cover and the input shaft, and effectively ensuring the sealing performance between the input shaft and the transparent cover.

[0076] It is easy for those skilled in the art to understand that the above-mentioned implementation modes can be freely combined and superimposed without conflict.

[0077] The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A high-speed input shaft rotating seal structure for a low-temperature end face seal tester, characterized in that: It includes a transparent cover and an input shaft. The transparent cover is provided with an input shaft hole, and the input shaft rotatably passes through the input shaft hole. A sealing assembly is provided between the transparent cover and the input shaft. The sealing assembly includes a first sealing ring, a spacer ring, and a second sealing ring arranged in sequence along the axial direction. An air cavity is formed between the first sealing ring, the spacer ring, the second sealing ring, and the input shaft. The transparent cover is provided with an air inlet and a ventilation port. The ventilation port is arranged on the hole wall of the input shaft hole. The air inlet is communicated with the ventilation port through an air delivery channel. The ventilation port is correspondingly arranged with the spacer ring. The spacer ring is provided with a plurality of through holes penetrating the spacer ring in the radial direction. The ventilation port is communicated with the air cavity through the through holes; When high-pressure gas is supplied to the air inlet, the high-pressure gas sequentially passes through the air delivery channel, the ventilation port, and the through holes of the spacer ring and enters the air cavity, and leaks out between the first sealing ring and the input shaft to form a first high-pressure sealing air film to support the first sealing ring; and leaks out between the second sealing ring and the input shaft to form a second high-pressure sealing air film to support the second sealing ring.

2. The high-speed input shaft rotary seal structure of the low-temperature end face seal tester according to claim 1, characterized in that: The first sealing ring is provided with a first lip, and a first spring is arranged in the first lip; the second sealing ring is provided with a second lip, and a second spring is arranged in the second lip. The opening directions of the first lip and the second lip are opposite.

3. The high-speed input shaft rotating seal structure of the low-temperature end face seal tester according to claim 2, characterized in that: A first abutting ring is arranged on one side of the first sealing ring close to the input shaft; a second abutting ring is arranged on one side of the second sealing ring close to the input shaft.

4. The high-speed input shaft rotating seal structure of the low-temperature end face seal tester according to claim 3, characterized in that: The cross sections of the first abutting ring and the second abutting ring are both triangular.

5. The high-speed input shaft rotary seal structure of the low-temperature end face seal tester according to claim 2, wherein: A first annular clamping groove is arranged on the inner side of the first lip; a second annular clamping groove is arranged on the inner side of the second lip.

6. The high-speed input shaft rotating seal structure of the low-temperature end face seal tester according to claim 1, wherein: A through hole groove is arranged on the outer side of the spacer ring, and the through hole is arranged at the bottom of the through hole groove.

7. The high-speed input shaft rotating seal structure of the low-temperature end face seal tester according to claim 1, characterized in that: The spacer ring is in tight fit with the input shaft hole.

8. The high-speed input shaft rotating seal structure of the low-temperature end face seal tester according to claim 1, wherein: A limiting convex ring is arranged at one end of the input shaft hole of the transparent cover.

9. The high-speed input shaft rotating seal structure of the low-temperature end face seal tester according to claim 8, characterized in that: It further includes a retaining ring. The retaining ring is fixed to the end of the input shaft hole far from the limiting convex ring by screws. A limiting groove for the sealing assembly is formed between the retaining ring and the limiting convex ring.

10. The high-speed input shaft rotary seal structure of the low-temperature end face seal tester according to claim 1, characterized in that: Both the first sealing ring and the second sealing ring are made of a rubber material with low-temperature resistance and toughness.

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