High-speed cryogenic sealing test bench
By designing a high-speed deep-cold seal test bench, using a contactlessly connected deep-cold seal chamber and telescopic spindle, combined with the bearing active heating system and corrugated pipe leakage monitoring, the problem of difficulty in simulating the entire working conditions of ultra-low temperature, high speed and high pressure is solved, and efficient optimization design and improvement of seals is achieved.
Patent Information
- Application Number
- CN202510374173.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-27
- Publication Date
- 2025-06-20
AI Technical Summary
The prior art is difficult to simulate the entire working conditions of ultra-low temperature, high speed and high pressure, which makes it difficult to accurately locate the failure mechanism when the seal is leaked or damaged during actual operation, and the traditional test bench cannot maintain a ultra-low temperature environment of -196℃.
A high-speed deep-cold sealing test bench is designed, using a contactlessly connected deep-cold sealing cavity, which stabilizes the -196℃ environment through low-temperature alloy material and cold-retaining layer. Combined with a telescopic spindle and bearing active heating system, the stable operation of ultra-low temperature and high speed is achieved, and the leakage rate is monitored in real time through bellows.
It realizes sealing performance testing in all operating conditions of ultra-low temperature, high speed and high pressure, provides quantitative data to support seal failure analysis and optimization design, significantly improves the optimization and improvement efficiency of low-temperature liquid seals, shortens the improvement cycle, and reduces operating costs.
Smart Images
Figure CN120176934A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of cryogenic experiments, and particularly relates to a high-speed cryogenic sealing test bench. Background Art
[0002] In the fields of petrochemical industry, aerospace transportation, etc., the safe operation of cryogenic liquid transportation equipment (such as liquid oxygen pumps, liquid nitrogen pumps) highly depends on the performance of seals. However, the current seal research and development faces multiple technical bottlenecks. Due to the lack of a test device that can simulate the full working conditions of ultra-low temperature of -196°C, high speed of 30,000 r / min, and high pressure of 10 MPa, the industry has long relied on theoretical calculations and empirical formulas for design, resulting in difficulties in accurately locating the failure mechanism (such as thermal stress deformation, cavitation wear, etc.) when the seal leaks or is damaged during actual operation. According to statistics, the equipment shutdown accidents caused by seal failures account for 45%, and the average improvement cycle is as long as 6 months. The traditional test bench adopts passive adiabatic design, and the heat exchange between the test chamber and the environment causes the temperature fluctuation to exceed ±5°C, and the problem of thermal expansion and contraction at low temperatures is not solved. The shrinkage rate of the main shaft material reaches 0.2% at -196°C, which is likely to cause bearing jamming, and the thermal stress generated at the connection between the seal chamber and the support due to the temperature difference can reach 30% of the material yield strength. Summary of the Invention
[0003] The purpose of the present invention is to provide a high-speed cryogenic sealing test bench, which for the first time realizes the sealing performance test of ultra-low temperature, high speed, and high pressure full working conditions through a cryogenic sealing cavity with non-contact connection. By real-time monitoring of key parameters such as the leakage rate and temperature field distribution in the closed chamber, it provides quantitative data support for seal failure analysis and optimization design, and greatly improves the optimization and improvement efficiency of cryogenic liquid seals.
[0004] The present invention is realized through the following technical solutions:
[0005] A high-speed cryogenic sealing test bench, comprising:
[0006] A test chamber system, the test chamber system includes support assemblies arranged at intervals relatively, and a cryogenic sealing cavity is detachably connected between the support assemblies through an adiabatic sealing connection assembly. A cavity for accommodating a test piece is arranged in the middle of the cryogenic sealing cavity;
[0007] A power transmission system, including a main shaft, the main shaft penetrates through the cryogenic sealing cavity and provides a rotational driving force for the test piece;
[0008] Wherein, a bellows is connected between the cryogenic sealing cavity and the support assembly on the non-motor side, and is used to form a closed chamber for collecting the leaked liquid or gas of the test piece.
[0009] In this solution, the test bench is detachably connected to the cryogenic sealed cavity through the support assembly in the test chamber system to form an independent ultra-low temperature test environment. The cryogenic sealed cavity is made of cryogenic alloy material and can stably maintain a liquid nitrogen environment of -196°C to simulate the sealing conditions of media such as liquid hydrogen and liquid oxygen. The main shaft of the power transmission system penetrates the cavity and is driven by a high-speed motor to achieve a maximum rotational speed of 30,000 r / min to simulate the dynamic sealing scenarios of equipment such as centrifugal pumps. The bellows on the non-motor side connect the cavity and the support assembly to form a closed chamber. The axial expansion and contraction of the bellows compensate for thermal expansion and contraction, and at the same time, the leakage rate is monitored in real time, providing a quantitative basis for the failure mechanism analysis of the seal under ultra-low temperature and high-speed conditions, effectively solving the problems of long improvement cycle and high cost caused by the inability of traditional test benches to reproduce real working conditions.
[0010] As an optimized solution of the test bench, the support assembly includes a support and a crossbeam. A plurality of crossbeams are provided and connected to the inner sidewall of the support. Support ears matching the crossbeams are provided at both ends of the cryogenic sealed cavity.
[0011] In this solution, through the combined structure of the support and multiple crossbeams, multiple crossbeams are horizontally arranged on the inner sidewall of the support to form a stable support framework. The support ears at both ends of the cryogenic sealed cavity are precisely matched with the crossbeams and are detachably fixed through the adiabatic sealing connection assembly, which not only realizes the reliable support of the cryogenic sealed cavity but also reduces the heat conduction path through the split structure.
[0012] As an optimized solution of the test bench, a groove is provided between the crossbeam and the support ear, and an adiabatic layer is laid in the groove.
[0013] In this solution, by machining a groove on the contact surface between the crossbeam and the support ear, a physical blockage of the heat conduction path is formed. At the same time, an efficient adiabatic layer (such as aerogel felt) is laid in the groove, reducing the heat conduction area between the cryogenic sealed cavity and the support assembly, effectively reducing the heat exchange rate between the test chamber and the environment, ensuring the stable maintenance of the -196°C ultra-low temperature environment, and controlling the temperature fluctuation within ±0.1°C. In addition, the groove structure increases the mechanical strength of the contact interface. Together with the detachable adiabatic sealing connection assembly, while ensuring the support stability of the cryogenic sealed cavity, the rapid disassembly and assembly of the test chamber are realized, meeting the test requirements of multiple types of seals.
[0014] As an optimized solution of the test bench, a gap is left between both ends of the cryogenic sealed cavity and the support assembly, and a cold insulation material is filled in the gap.
[0015] In this solution, by leaving a gap between both ends of the cryogenic sealed cavity and the support assembly, an air adiabatic layer is formed, and a cold insulation material (such as polyurethane foam) is filled in the gap, further effectively blocking the heat conduction path between the cryogenic sealed cavity and the support assembly.
[0016] As an optimized solution for the test bench, a cold insulation layer is coated on the outer side wall of the cryogenic sealing cavity.
[0017] In this solution, by coating a cold insulation layer on the outer side wall of the cryogenic sealing cavity, an efficient thermal barrier is formed, reducing the heat exchange amount between the test chamber and the environment by more than 90%, ensuring the stable maintenance of the ultra-low temperature environment of -196°C, and controlling the temperature fluctuation within ±0.1°C.
[0018] As an optimized solution for the test bench, the test bench further includes a main shaft support system, and the main shaft support system includes an end cover assembly, and the end cover assembly is connected between the support assemblies and supports the main shaft.
[0019] In this solution, by adding an end cover assembly between the support assemblies, a three-point support structure is formed, effectively improving the rigidity and stability of the main shaft during high-speed rotation (up to 30000 r / min), and reducing the flexural deformation.
[0020] As an optimized solution for the test bench, the end cover assembly includes a bearing housing and a bearing. The bearing housing is connected between the support assemblies. A bearing cavity matching the bearing is provided in the middle of the bearing housing. The inner ring of the bearing is fixed to the main shaft, and the outer ring of the bearing is in small clearance fit with the wall surface of the bearing cavity. When the main shaft expands and contracts, the bearing follows the main shaft and slides axially along the bearing cavity.
[0021] In this solution, through the precise fit between the chamber in the middle of the bearing housing that matches the bearing and the main shaft, the stable support and free expansion and contraction of the main shaft in a low-temperature environment are realized. The inner ring of the bearing is fixed to the main shaft with interference fit, and the outer ring is in small clearance fit with the wall surface of the bearing cavity, allowing the bearing to freely slide axially within the range along with the main shaft, effectively compensating for the 0.2% shrinkage deformation of the main shaft material at -196°C low temperature and avoiding bearing jamming. At the same time, the bearing housing is rigidly connected to the support assemblies to form a three-point support structure, ensuring that the radial runout of the main shaft during high-speed rotation at 30000 r / min is ≤0.01 mm, and the axial displacement of the bearing is restricted by the inner limit plate to ensure the rotational stability of the seal test.
[0022] As an optimized solution for the test bench, a heating cavity surrounding the bearing cavity is further provided inside the bearing housing, and a circulating hot fluid is introduced into the heating cavity.
[0023] In this solution, an annular heating cavity surrounding the bearing cavity is opened inside the bearing housing, and a circulating thermal fluid with controllable temperature (control accuracy ±2°C) is introduced. An air gap is reserved between the outer ring of the bearing and the heating cavity to achieve active regulation of the bearing operating temperature: when the test bench is in an ultra-low temperature environment of -196°C, the heating cavity can maintain the bearing temperature above -20°C, avoiding lubrication failure and bearing jamming caused by low temperature; when frictional heat is generated during the high-speed rotation (30,000 r / min) of the main shaft, the heating cavity can remove the excess heat through the circulating fluid to ensure the stable operation of the bearing below 150°C.
[0024] As an optimized solution for the test bench, the end cover assembly further includes an outer end cover and an inner limiting plate, and the outer end cover and the inner limiting plate are respectively connected to the outer end and the inner end of the bearing cavity;
[0025] Among them, the outer end cover is hermetically connected to the bearing housing through an O-ring seal, and the inner limiting plate extends radially along the bearing cavity.
[0026] In this solution, the end cover assembly realizes the axial positioning and sealing protection of the bearing through the double limiting structure of the outer end cover and the inner limiting plate. The outer end cover is connected to the bearing housing by a detachable flange, and a dynamic sealing barrier is formed through the O-ring seal to prevent external impurities from invading the bearing cavity and maintain the airtightness of the test chamber; the inner limiting plate extends radially and is embedded in the inner end of the bearing cavity, contacting the outer ring of the bearing to form a mechanical limit, restricting the axial displacement of the bearing during the telescopic movement of the main shaft, ensuring that the bearing is always in the best working position; the two cooperate with the active temperature control system of the heating cavity of the bearing housing to maintain the stable operation of the bearing in an ultra-low temperature environment of -196°C, while allowing the main shaft to freely expand and contract to compensate for thermal expansion and contraction, effectively solving the technical problem of easy jamming of the traditional test bench bearing, and ensuring the sealing test accuracy and structural reliability during high-speed rotation (30,000 r / min).
[0027] As an optimized solution for the test bench, a temperature measuring hole is opened on the bearing housing, and the temperature measuring hole is communicated with the bearing cavity.
[0028] In this solution, by opening a temperature measuring hole on the bearing housing that is communicated with the bearing cavity, real-time in-situ monitoring of the bearing operating temperature is achieved. A K-type thermocouple can be inserted into the temperature measuring hole to directly measure the temperature inside the bearing cavity, and the temperature data is real-time fed back to the control system to dynamically adjust the temperature of the circulating thermal fluid in the heating cavity, ensuring that the bearing maintains an appropriate operating temperature in an ultra-low temperature environment of -196°C, avoiding lubrication failure and bearing jamming caused by low temperature; at the same time, the temperature measuring hole data provides a key basis for bearing failure analysis, triggering an alarm when the temperature fluctuates abnormally, preventing the test bench from stopping or the seal being damaged due to bearing failure, and cooperating with the dynamic compensation structure of the bearing housing to ensure the continuous and stable operation of the test bench, providing a reliable temperature monitoring and control basis for ultra-low temperature high-speed sealing performance testing.
[0029] Compared with the prior art, the present invention has the following advantages and beneficial effects:
[0030] By constructing a cryogenic sealing cavity and a detachable end cover assembly to form an independent test environment, combining a telescopic main shaft to compensate for low-temperature shrinkage and a bearing active heating system to maintain the reliability of operation, the present invention realizes stable operation at -196°C ultra-low temperature and 30,000 r / min high speed; and by using a bellows to collect leakage media in real time and accurately monitor the leakage rate, and cooperating with the temperature measurement holes on the end cover to obtain the temperature field data of the sealing cavity, it provides a quantitative basis for the selection of sealing material and the optimization of the structure, and greatly shortens the improvement cycle. In addition, the present invention adopts a split adiabatic structure to reduce the heat conduction area by more than 90%, and cooperates with the modular installation design, which significantly improves the test efficiency and reduces the operation cost. BRIEF DESCRIPTION OF THE DRAWINGS
[0031] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, form a part of this application, and do not constitute a limitation to the embodiments of the present invention. In the drawings:
[0032] Figure 1 is a sectional structure schematic diagram of the present invention;
[0033] Figure 2 is Figure 1 a schematic diagram of the structure marked A in;
[0034] Figure 3 is Figure 1 a schematic diagram of the structure marked B in;
[0035] Figure 4 is a sectional structure schematic diagram of the present invention.
[0036] The reference signs in the drawings and the corresponding component names:
[0037] 1 - Cryogenic sealing cavity body, 2 - End cover assembly, 21 - Bearing seat, 22 - Temperature measurement hole, 23 - O-ring seal, 24 - Outer end cover, 25 - Heating cavity, 26 - Inner limiting plate, 27 - Outer limiting plate, 3 - Support assembly, 31 - Support, 32 - Cross beam, 4 - Coupling, 5 - High-speed motor, 6 - Motor control cabinet, 7 - Main shaft, 8 - Bellows, 9 - Base, 10 - Limiting bushing, 11 - Bearing, 12 - Thermal insulation layer, 13 - Ear. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0038] In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and the drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and do not limit the present invention.
[0039] Embodiment 1
[0040] Embodiment 1 provides a high-speed cryogenic sealing test bench, as Figure 1 shown, which includes a test chamber system, a power transmission system and a main shaft support system;
[0041] Among them, please refer to Figure 1 shown, the power transmission system includes a main shaft 7. The main shaft 7 penetrates through the cryogenic sealing cavity 1 and is rotationally connected to the main shaft support system. The high-speed motor 5 is connected to the main shaft 7 through a coupling 4. The high-speed motor 5 is started through the motor control cabinet 6 to provide a high-speed rotation driving force for the test piece.
[0042] Among them, please refer to Figure 1 and Figure 4 shown, the test chamber system includes support assemblies 3 arranged at relatively spaced intervals. The support assemblies 3 are detachably connected to the cryogenic sealing cavity 1 through an adiabatic sealing connection assembly. A cavity for accommodating the test piece is provided in the middle of the cryogenic sealing cavity 1. Specifically, the support assembly 3 includes a support 31, and the adiabatic sealing connection assembly includes a cross beam 32 and a lug 13. The supports 31 are connected to the base 9 at relatively spaced intervals. Two cross beams 32 are provided and are evenly connected to the opposite inner side walls of the supports 31. The two ends of the cryogenic sealing cavity 1 are bolted together through lugs 13 matching the cross beam 32, so that the cryogenic sealing cavity 1 is erected between the supports 31, forming a split structure of the cryogenic sealing cavity 1 and the support assembly 3. And a bellows 8 is connected between the cryogenic sealing cavity 1 and the support 31 on the non-motor side. A closed chamber for collecting the leaked liquid or gas of the test piece is formed between the bellows 8 and the support 31. A liquid collection tank and a leakage sensor are integrated at the bottom of the closed chamber to monitor the leakage rate in real time, providing a quantitative basis for the failure mechanism analysis of the seal under ultra-low temperature and high-speed working conditions.
[0043] At the same time, in order to reduce the heat conduction path, a groove is provided between the cross beam 32 and the lug 13, and an adiabatic layer 12, such as aerogel felt, is laid in the groove. The adiabatic layer 12 greatly reduces the heat conduction area between the cryogenic sealing cavity 1 and the support 31, effectively reducing the heat exchange rate between the test chamber and the environment, and ensuring the stable maintenance of the -196°C ultra-low temperature environment.
[0044] Of course, in some embodiments, to further effectively block the heat conduction path between the cryogenic sealing cavity 1 and the support 31, gaps are left between the two ends of the cryogenic sealing cavity 1 and the support 31 to form an air adiabatic layer. The gap is filled with cold insulation materials, such as polyurethane foam. At the same time, the outer sidewall of the cryogenic sealing cavity 1 is coated with a composite cold insulation layer composed of a vacuum insulation panel and polyurethane foam. The cold insulation materials in the gap between the cold insulation layer and the support assembly and the insulation layer 12 in the crossbeam groove work together to construct a multi-level adiabatic system, effectively reducing the heat dissipation from the test chamber to the environment, ensuring the test accuracy of the seal under ultra-low temperature conditions, and cooperating with the low-temperature alloy material of the cryogenic sealing cavity to accurately simulate the sealing performance of media such as liquid hydrogen and liquid oxygen.
[0045] Among them, please refer to Figures 1 - 3 As shown, to effectively improve the rigidity and stability of the main shaft 7 during high-speed rotation (up to 30,000 r / min) and reduce flexural deformation, the above-mentioned main shaft support system includes 2 end cap assemblies. The end cap assembly 2 is connected between the support assemblies 3 and supports the main shaft 7.
[0046] Specifically, please refer to Figure 2 As shown, the end cap assembly 2 on the non-motor side includes a limit bushing 10, a bearing housing 21 and a bearing 11. The bearing housing 21 is connected between the supports 31. A bearing cavity matching the bearing 11 is provided in the middle of the bearing housing 21. The limit bushing 10 is fixed to the main shaft 7. The inner ring of the bearing 11 is fixed to the limit bushing 10. The outer ring of the bearing 11 is in small clearance fit with the wall surface of the bearing cavity. When the main shaft 7 expands and contracts, the bearing 11 follows the main shaft 7 and slides axially along the bearing cavity. For example, the outer ring of the bearing 11 and the wall surface of the bearing cavity adopt an H7 / g6 small clearance fit (clearance 0.02 - 0.05 mm), allowing the bearing 11 to freely slide along the main shaft within an axial range of 0.5 - 1 mm, effectively compensating for the 0.2% shrinkage deformation of the main shaft material at -196°C and avoiding bearing jamming.
[0047] At the same time, the end cap assembly 2 also includes an outer end cap 24 and an inner limit plate 26. The outer end cap 24 and the inner limit plate 26 are respectively connected to the outer end and the inner end of the bearing cavity. The outer end cap 24 and the bearing housing 21 are sealed and connected through an O-ring 23 to prevent leakage of low-temperature media. The inner limit plate 26 extends radially along the bearing cavity and contacts the outer ring of the bearing to form a mechanical limit, restricting the axial displacement of the bearing 11 during the expansion and contraction of the main shaft 7 to ≤0.5 mm, ensuring that the bearing is always in the best working position.
[0048] Similarly, the end cover assembly 2 on the motor side also includes a bearing seat 21 and a bearing 11. The bearing seat 21 is connected between the supports 31. A bearing cavity matching the bearing 11 is opened in the middle of the bearing seat 21. The limiting sleeve 10 is fixed to the main shaft 7. The inner ring of the bearing 11 is fixed to the limiting sleeve 10. The outer ring of the bearing 11 is matched with a small clearance between the wall of the bearing cavity. When the main shaft 7 is extended or retracted, the bearing 11 follows the main shaft 7 and slides axially along the bearing cavity. For example, the outer ring of the bearing 11 and the wall of the bearing cavity adopt a H7 / g6 small clearance fit (clearance 0.02-0.05mm), allowing the bearing 11 to slide freely with the main shaft within an axial range of 0.5-1mm, effectively compensating for the 0.2% shrinkage deformation of the main shaft material at a low temperature of -196°C, and avoiding the bearing from getting stuck.
[0049] Also, see Figure 3 As shown, the end cover assembly 2 also includes an outer limit plate 27 and an inner limit plate 26, which are respectively connected to the outer end and the inner end of the bearing cavity. The outer limit plate 27 and the inner limit plate 26 both extend radially along the bearing cavity and contact with the outer ring of the bearing to form a mechanical limit, thereby limiting the axial displacement of the bearing 11 when the main shaft 7 is extended or retracted.
[0050] Example 2
[0051] In order to avoid lubrication failure and bearing jamming caused by low temperature, this embodiment 2 provides a high-speed cryogenic sealing test bench based on embodiment 1, such as Figure 2 and Figure 3 As shown, a heating chamber 25 surrounding the bearing cavity is also provided inside the bearing seat 21. A temperature-controllable circulating hot fluid is introduced into the heating chamber 25 with a control accuracy of ±2°C. An air gap is retained between the outer ring of the bearing and the heating chamber 25 to achieve active regulation of the bearing working temperature. When the test bench is in an ultra-low temperature environment of -196°C, the heating chamber 25 can maintain the bearing temperature above -20°C to avoid lubrication failure and bearing jamming due to low temperature. When the spindle rotates at high speed (30,000 r / min) to generate friction heat, the heating chamber 25 can take away excess heat through the circulating fluid to ensure that the bearing runs stably below 150°C.
[0052] At the same time, a temperature measuring hole 22 is provided on the bearing seat 21 , and the temperature measuring hole 22 is connected to the bearing cavity. By providing the temperature measuring hole 22 connected to the bearing cavity on the bearing seat 21 , real-time in-situ monitoring of the working temperature of the bearing 11 can be achieved.
[0053] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
Claims
1. A high-speed cryogenic sealing test bench, characterized in that: include: A test chamber system, the test chamber system comprising support assemblies (3) arranged at a relative interval, the support assemblies (3) being detachably connected to a cryogenic sealed chamber (1) via a heat-insulating sealed connection assembly, the middle of the cryogenic sealed chamber (1) being provided with a cavity for accommodating a test piece; A power transmission system, comprising a main shaft (7), wherein the main shaft (7) passes through the cryogenic sealing cavity (1) and provides a rotational driving force for the test piece; Wherein, a bellows (8) is connected between the cryogenic sealing cavity (1) and the support assembly on the non-motor side, so as to form a closed chamber for collecting liquid or gas leaked from the test piece.
2. A high-speed cryogenic sealing test bench according to claim 1, characterized in that: The support assembly (3) comprises a support (31) and a crossbeam (32), wherein a plurality of crossbeams (32) are provided and connected to the inner wall of the support (31), and support ears (13) matching the crossbeams (32) are provided at both ends of the cryogenic sealing cavity (1).
3. A high-speed cryogenic sealing test bench according to claim 2, characterized in that: A groove is provided between the cross beam (32) and the support lug (13), and a heat insulating layer (12) is laid in the groove.
4. A high-speed cryogenic sealing test bench according to claim 2, characterized in that: Gaps are left between the two ends of the cryogenic sealed cavity (1) and the support assembly (3), and the gaps are filled with cold-retaining and heat-insulating materials.
5. A high-speed cryogenic sealing test bench according to claim 2, characterized in that: The outer side wall of the deep-cold sealed cavity (1) is coated with a cold-insulating layer.
6. A high-speed cryogenic sealing test bench according to any one of claims 1 to 5, characterized in that: The test bench also includes a main shaft support system, which includes an end cover assembly (2). The end cover assembly (2) is connected between the support assemblies (3) and supports the main shaft (7).
7. A high-speed cryogenic sealing test bench according to claim 6, characterized in that: The end cover assembly (2) comprises a bearing seat (21) and a bearing (11); the bearing seat (21) is connected between the support assemblies (3); a bearing cavity matching the bearing (11) is arranged in the middle of the bearing seat (21); the inner ring of the bearing (11) is fixed to the main shaft (7); the outer ring of the bearing (11) is fitted with a small clearance between the wall of the bearing cavity; when the main shaft (7) is extended or retracted, the bearing (11) follows the main shaft (7) and slides axially along the bearing cavity.
8. A high-speed cryogenic sealing test bench according to claim 7, characterized in that: A heating chamber (25) surrounding the bearing chamber is also provided inside the bearing seat (21), and a circulating hot fluid is passed into the heating chamber (25).
9. A high-speed cryogenic sealing test bench according to claim 7, characterized in that: The end cover assembly (2) further comprises an outer end cover (24) and an inner limit plate (26), wherein the outer end cover (24) and the inner limit plate (26) are respectively connected to the outer end and the inner end of the bearing cavity; The outer end cover (24) is sealed to the bearing seat (21) via an O-ring (23), and the inner limit plate (26) extends radially along the bearing cavity.
10. A high-speed cryogenic sealing test bench according to claim 7, characterized in that: The bearing seat (21) is provided with a temperature measuring hole (22), and the temperature measuring hole (22) is communicated with the bearing cavity.