A liquid rocket engine turbine pump combination seal test device and system

Abstract

The application discloses a liquid rocket engine turbine pump combined sealing test device and system, which combines high-pressure low-temperature end face sealing and normal-temperature circumferential sectional sealing together, and adds a nozzle on a gas medium supply system to throttle and depressurize before sectional sealing and simulate a real airflow state, can simulate real working conditions of low-temperature high-pressure end face sealing and normal-temperature circumferential sectional sealing of a liquid rocket engine turbine pump in a low-temperature normal-temperature mixed medium, and can simulate real working conditions of different sealing pressures, and can complete multiple dynamic sealing products at one time, improves test efficiency and provides reliable test data support for engine development.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of liquid rocket engine cryogenic sealing test, and particularly relates to a test device and system capable of simultaneously simulating two-piece cryogenic high-pressure end face sealing and circumferential segmented sealing in a turbine pump. BACKGROUND

[0002] Currently, the development of reusable liquid rocket engines has higher requirements for the reliability of turbine pumps. Reusable liquid rocket engines mostly use liquid oxygen and methane fuel, and the turbine pumps mostly use end face sealing and circumferential segmented sealing to isolate liquid oxygen and liquid methane. Therefore, cryogenic end face sealing and segmented sealing are key components of the turbine pump, and are crucial to the safe operation and function realization of the turbine pump. The working medium isolated by the cryogenic end face sealing and the circumferential segmented sealing is different, the compression amount and working pressure of the two end face sealings are different, and the circumferential segmented sealing is used to seal gas.

[0003] Due to the requirements of engine reusability and the particularity of dynamic sealing working conditions, before the test run and launch of the liquid rocket engine, verification tests need to be carried out on the key dynamic sealing components to obtain their sealing performance and wear performance. However, the current dynamic sealing test device can only carry out low-temperature or normal-temperature operation tests on one or two products respectively, and cannot simulate the real working conditions of the combination of different types of dynamic sealings and different working conditions of dynamic sealings in the turbine pump. SUMMARY

[0004] The technical problem solved by the present application is to overcome the shortcomings of the prior art and provide a liquid rocket engine turbine pump combined sealing test device and system, which can simultaneously simulate the mixed examination of two-piece cryogenic high-pressure end face sealing and circumferential segmented sealing in a turbine pump, thereby providing a basis for the development of reusable liquid rocket engines.

[0005] The technical solution of the present application is:

[0006] A liquid rocket engine turbine pump combined sealing test device, comprising a rotor assembly, a housing assembly, and a medium supply system; a cryogenic end face sealing to be tested is sleeved on the rotor assembly according to a certain compression amount and is in contact with the dynamic ring of the rotor assembly; a circumferential segmented sealing to be tested is sleeved on the rotor assembly and forms a sealing gap with the shaft sleeve of the rotor assembly; the end face sealing and the circumferential segmented sealing are both fixed on the housing assembly; the end face sealing, the circumferential segmented sealing, and the housing assembly form a plurality of sealing cavities and leakage cavities with the rotor assembly, and the medium supply system is in communication with the sealing cavities to provide low-temperature liquid medium or normal-temperature gas medium for the sealing cavities;

[0007] During the test, the rotor assembly rotates, the end face seal to be tested contacts with the dynamic ring to dynamically seal the sealing cavity, the circumferential segmented seal dynamically seals the gap between the shaft sleeve and the gas medium, the inlet flow of each sealing cavity and the leakage of each leakage cavity are monitored, and the sealing characteristics and working stability of the low-temperature end face seal and the circumferential segmented seal are obtained.

[0008] Preferably, the shell assembly comprises a first shell, a second shell, a third shell, a fourth shell and a fifth shell.

[0009] One side of the first shell is referred to as the front end, and one side of the fifth shell is referred to as the rear end.

[0010] The rotor assembly comprises a main shaft, a front liquid seal wheel, a rear liquid seal wheel, a front bearing and a rear bearing.

[0011] The front end of the main shaft is fixedly installed on the second shell through the front bearing, and the rear end is fixedly installed on the fourth shell through the rear bearing.

[0012] The rear end of the main shaft is provided with spline teeth, and the end of the shaft head is provided with a threaded hole; the front end of the main shaft is provided with a speed measuring tooth, and the end of the shaft head is a flat structure.

[0013] The end of the shaft head of the front end of the main shaft is provided with a displacement sensor for monitoring the axial vibration of the test device during high-speed operation, and indirectly reflecting the change of the axial force of the test device; the radial position of the front end of the main shaft is provided with a speed measuring sensor for monitoring the real-time speed of the test device during high-speed operation.

[0014] The end face seal I is installed at the front end of the third shell, and the compression amount is adjusted by the length of the front dynamic ring sleeve; the circumferential segmented seal is installed at the rear end of the third shell; the end face seal II is installed at the front end of the fourth shell, and the compression amount is adjusted by the length of the rear dynamic ring sleeve.

[0015] The front liquid seal wheel is threadedly installed at the front end of the main shaft, and the rear liquid seal wheel is threadedly installed at the rear end of the main shaft; the screw rotation direction of the front liquid seal wheel and the rear liquid seal wheel is opposite, and the front liquid seal wheel is located between the first shell and the front bearing, and the rear liquid seal wheel is located between the fifth shell and the rear bearing; the front shaft seal is installed on the main shaft and located at the front end of the front liquid seal wheel; the rear shaft seal is installed on the main shaft and located at the rear end of the rear liquid seal wheel, and the front liquid seal wheel and the front shaft seal, and the rear liquid seal wheel and the rear shaft seal form a combined seal of the rotor shaft head.

[0016] The end face seal I forms a sealed cavity I with the front liquid seal wheel, the sealed pressure of which is recorded as P1, and the low-temperature medium enters through the first medium inlet; the circumferential segmented seal forms a sealed cavity II inside, the sealed pressure of which is recorded as P2, and the normal-temperature gas medium enters through the second medium inlet; the end face seal II forms a sealed cavity III with the rear liquid seal wheel, the sealed pressure of which is recorded as P3, and the low-temperature medium enters through the third medium inlet; the first medium inlet and the second medium inlet are both the pipe mouths of the third shell, and the third medium inlet is the pipe mouth of the fourth shell.

[0017] The circumferential segmented seal and the end face seal I form a leakage cavity I therebetween, and the circumferential segmented seal and the end face seal II form a leakage cavity II therebetween.

[0018] Preferably, the front bearing outer ring is sleeved on the front bearing outer sleeve, the front bearing outer sleeve is fixedly installed on the second shell through bolts; the inner ring of the front bearing is installed on the front bearing inner sleeve, and the inner ring and the front bearing inner sleeve are fixed on the main shaft through the front bearing pressing cap; the front end of the outer ring of the front bearing is in contact with the first disc spring, the first disc spring is installed on the first disc spring holder, and the first disc spring is compressed and positioned through the front bearing pressing cap fixedly installed on the front bearing outer sleeve and the front disc spring adjusting gasket, the front disc spring adjusting gasket being installed between the first disc spring holder and the front bearing pressing cap.

[0019] Preferably, the rear bearing outer ring is sleeved on the rear bearing outer sleeve, the rear bearing outer sleeve is fixedly installed on the fourth shell through bolts; the inner ring of the rear bearing is installed on the rear bearing inner sleeve, and the inner ring and the rear bearing inner sleeve are fixed on the main shaft through the rear bearing pressing cap; the rear end of the outer ring of the rear bearing is in contact with the second disc spring, the second disc spring is installed on the second disc spring holder, and the second disc spring is compressed and positioned through the rear bearing pressing cap fixedly installed on the rear bearing outer sleeve and the rear disc spring adjusting gasket, the rear disc spring adjusting gasket being installed between the second disc spring holder and the rear bearing pressing cap.

[0020] Preferably, the front bearing and the rear bearing are both in clearance fit with the front bearing outer sleeve and the rear bearing outer sleeve, and the materials of the front bearing outer ring and the front bearing outer sleeve and the rear bearing outer ring and the rear bearing outer sleeve are the same, and the one-side fit clearance of the front bearing outer ring and the front bearing outer sleeve and the rear bearing outer ring and the rear bearing outer sleeve is 0.01-0.015 mm at low temperature.

[0021] The axial pre-tightening force of the front bearing is realized through compression of the first disc spring, the axial pre-tightening force of the rear bearing is realized through compression of the second disc spring, the compression amount of the first disc spring is realized through adjustment of the front disc spring adjusting gasket, and the compression amount of the second disc spring is realized through adjustment of the rear disc spring adjusting gasket.

[0022] Preferably, the front shaft seal and the rear shaft seal are both low-temperature leather bowl contact type seals.

[0023] Preferably, the total axial length H of the outer circle of the front and rear liquid seal wheels is the same, and the inner diameter D1 of the blades is the same; the total axial length of the shell assembly is L, and the inner hole diameter of the shell assembly is D3, then D3-D 2前 =1mm, D3-D 2后 =1mm, where D 2前 is the outer diameter of the front liquid seal wheel blade, and D 2后 is the outer diameter of the rear liquid seal wheel blade.

[0024] Preferably, the sealable pressures of the front and rear liquid seal wheels are P 前 and P 后 respectively, and the outer diameters are D 2前 and D 2后 respectively. When the pressures of the sealing cavities I and III are P1=P3, the axial forces F 轴 generated by the front and rear ends of the main shaft are 0, then the outer diameters D 2前 of the front and rear liquid seal wheels are D 2后 , at this time the sealing pressure satisfies P 前 =P 后 ≤0.5MPa, and the axial forces F 轮 generated by the front and rear liquid seal wheels are 0.

[0025] Preferably, when the pressures of the sealing cavities I and III are P1≠P3, the outer diameters D2 of the front and rear liquid seal wheels are selected to be different sizes at this time, P 前 =P 后 ≤P 气 , and P 气 is the gasification pressure of liquid nitrogen under local atmospheric pressure.

[0026] A liquid rocket engine turbine pump combined sealing test system, comprising a first low-temperature pressure container, a second low-temperature pressure container, a nitrogen bottle group, a low-temperature pneumatic stop valve, a low-temperature manual stop valve, a low-temperature mass flowmeter, a manual stop valve, a pressure reducing valve, a normal-temperature mass flowmeter, a nozzle, a low-temperature electric regulating valve, a gasifier, and a volumetric flowmeter;

[0027] The first low-temperature pressure container is connected to the sealing cavity I through a first pipeline, and the second low-temperature pressure container is connected to the sealing cavity III through a second pipeline. Low-temperature pneumatic stop valves, low-temperature manual stop valves, and low-temperature mass flowmeters are arranged in sequence on the first pipeline and the second pipeline along the medium inflow direction. The low-temperature medium enters the sealing cavity I to cool the front bearing, enters the sealing cavity III to cool the rear bearing, and then part of the medium is discharged after passing through the low-temperature electric regulating valve, part of the medium is discharged after passing through the front and rear liquid seal wheels and their shaft seals, and finally part of the medium enters the leakage cavity I through the end face seal I and enters the leakage cavity II through the end face seal II, and finally passes through the gasifier and the mass flowmeter for discharge.

[0028] The nitrogen cylinder group is connected with the sealed cavity II through a gas pipeline, and a manual stop valve, a pressure reducing valve, a normal-temperature mass flow meter and a nozzle are sequentially arranged on the gas pipeline.

[0029] Compared with the prior art, the present application has the following beneficial effects:

[0030] (1) The test device of the present application combines high-pressure low-temperature end face sealing and normal-temperature circumferential sectional sealing together, and adds a nozzle on the gas medium supply system to throttle and reduce pressure before sectional sealing and simulate the real gas flow state, which can simulate the real working conditions of low-temperature high-pressure end face sealing and normal-temperature circumferential sectional sealing of a liquid rocket engine turbine pump in a mixed medium of low temperature and normal temperature, and can simulate the real working conditions of different sealing pressures, and can complete multiple dynamic sealing products at one time, improve the test efficiency and provide reliable test data support for the development of the engine.

[0031] (2) The main shaft of the test device of the present application adopts a double-liquid seal wheel sealing structure, and the front and rear ends adopt a leather cup sealing structure, which can balance the axial force generated by different low-temperature end face seals in the test device under different pressures and speeds, and the test device adopts a double-disc spring pre-tightening scheme, and the front and rear bearings can move axially in the bearing sleeve, when the axial force changes greatly, the axial displacement of the main shaft front end can be reflected through the displacement sensor, and then the working state of the test device bearing can be judged, and the real-time speed of the test device can be monitored through the speed sensor arranged at the front end of the main shaft, and the working state of the test device can be judged, and multiple monitoring methods greatly improve the safety and reliability of the test device. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 The present application is a liquid rocket engine turbine pump combined sealing test device.

[0033] Figure 2 The present application is a liquid rocket engine turbine pump combined sealing test device.

[0034] Figure 3 The present application is a liquid rocket engine turbine pump combined sealing test device. DETAILED DESCRIPTION

[0035] The present application will be further described below with reference to the accompanying drawings.

[0036] In order to meet the development requirements of reusable liquid rocket engine, different compression amounts, sealing pressures and different medium real working conditions of different dynamic sealing structure combinations in a turbine pump are simulated, and a plurality of dynamic sealing products can be completed at one time to improve the test efficiency, a combined sealing test device of a turbine pump of a reusable liquid rocket engine is provided, so as to provide basic support for the development of the reusable liquid rocket engine.

[0037] The main structural components of the full-system combined sealing test device of the application are shown in Figure 1 The end face sealing to be tested is sleeved on the rotor assembly in contact with the dynamic ring according to a certain compression amount and is fixed with the shell assembly, and the circumferential segmented sealing to be tested is sleeved on the rotor assembly to form a sealing gap with the shaft sleeve and is fixed with the shell assembly. Different sealing cavities and leakage cavities are formed between the end face sealing, the circumferential segmented sealing, the shell assembly and the rotor assembly, a medium supply system is in communication with the sealing cavities for providing low-temperature liquid medium or normal-temperature gas medium for the sealing cavities, and a flowmeter is in communication with the leakage cavities at the back for measuring the leakage amounts of the leakage cavities.

[0038] During the test, the rotor assembly rotates, the low-temperature end face sealing to be tested contacts the dynamic ring to dynamically seal the sealing cavities, and the circumferential segmented sealing forms a gap sealing with the shaft sleeve to dynamically seal the gas medium, and the sealing characteristics and working stability of the low-temperature end face sealing and the circumferential segmented sealing are obtained by monitoring the inlet flow and the flow of each leakage cavity.

[0039] The full-system combined sealing test device comprises a shell assembly and a rotor component, the shell assembly comprises a first shell 1, a second shell 2, a third shell 3, a fourth shell 4 and a fifth shell 5.

[0040] One side of the first shell 1 is referred to as the front side, and one side of the fifth shell 5 is referred to as the back side.

[0041] The rotor component comprises a main shaft 6, a front liquid seal wheel 7, a back liquid seal wheel 34, a front bearing 10 and a back bearing 23, the front bearing is located at the front side of the test device, and the back bearing is located at the back side of the test device.

[0042] One end of the main shaft 6 is fixedly installed on the second shell 2 through the front bearing 10 and the front bearing outer sleeve 11, and the other end penetrates through the back bearing 23 and the back bearing outer sleeve 25 and is fixedly installed on the fourth shell 4.

[0043] The rear end of the main shaft 6 is provided with spline teeth, the number of teeth is 20, the modulus is 1.5, the pressure angle is 30°, and a threaded hole is arranged at the end of the shaft head, and the front end of the main shaft 6 is provided with a speed measuring tooth, and the end of the shaft head is a plane structure.

[0044] The front end of the main shaft 6 is provided with a displacement sensor 39 to monitor the axial vibration of the test device during high-speed operation, and indirectly reflect the change of the axial force of the test device; the radial position of the front end of the main shaft 6 is provided with a rotational speed measuring sensor to monitor the real-time rotational speed of the test device during high-speed operation.

[0045] The outer ring of the front bearing 10 is sleeved on the front bearing outer sleeve 11, which is fixedly installed on the second housing 2 by bolts. The inner ring of the front bearing 10 is installed on the front bearing inner sleeve 9, and the inner ring and the bearing inner sleeve 9 are fixed on the main shaft 6 by the front bearing pressing cap 8; the front end of the outer ring of the front bearing 10 is in contact with the first disc spring 261, which is installed on the first disc spring holder 271 and is positioned by the front bearing pressing cap 291 fixedly installed on the front bearing outer sleeve 11 and the disc spring adjusting gasket 28 therebetween.

[0046] The outer ring of the rear bearing 23 is sleeved on the rear bearing outer sleeve 25, which is fixedly installed on the fourth housing 4 by bolts. The inner ring of the rear bearing 23 is installed on the rear bearing inner sleeve 24, and the inner ring and the bearing inner sleeve 24 are fixed on the main shaft 6 by the rear bearing pressing cap 30; the rear end of the outer ring of the rear bearing 23 is in contact with the second disc spring 262, which is installed on the second disc spring holder 272 and is positioned by the rear bearing pressing cap 292 fixedly installed on the rear bearing outer sleeve 25 and the disc spring adjusting gasket 28.

[0047] The front bearing 10 and the front bearing outer sleeve 11, the rear bearing 23 and the rear bearing outer sleeve 25 are all gap fit, the materials of the bearing outer rings and the front bearing outer sleeve 11 and the rear bearing outer sleeve 25 are the same, the one-way fit gap at low temperature is 0.01-0.015mm, when the axial force changes, the bearing outer rings can move axially in the front and rear bearing outer sleeves, and at the same time, the main shaft 6 can move axially.

[0048] The axial pre-tightening force of the front bearing 10 and the rear bearing 23 is realized by the compression of the disc spring, and the compression amount of the disc spring can be realized by the disc spring adjusting gasket with different thicknesses at the front end or the rear end.

[0049] The end face seal I 16 is installed at the front end of the third housing 3, and the compression amount thereof is adjusted by the front movable ring shaft sleeve 15 with different lengths; the circumferential sectional seal 18 is installed at the rear end of the third housing 3; the end face seal II 19 is installed at the front end of the fourth housing 4, and the compression amount thereof is adjusted by the rear movable ring shaft sleeve 20 with different lengths. Figure 1 The middle 14, 22 is a movable ring, and 13, 21, 30 is a compression nut

[0050] The liquid seal wheel is installed on the front and rear ends of the main shaft 6, and comprises a front liquid seal wheel 7 and a rear liquid seal wheel 34, which are threadedly connected with the main shaft 6, and the thread rotation directions of the front liquid seal wheel 7 and the rear liquid seal wheel 34 are opposite.

[0051] The front liquid seal wheel 7 is located between the first shell 1 and the front bearing, and the rear liquid seal wheel 34 is located between the fifth shell 5 and the rear bearing; the front and rear liquid seal wheels and the shaft seal form a rotor shaft head combined seal.

[0052] The shaft seal is a low-temperature leather bowl contact seal, and the leather bowl 35 and the leather bowl gasket 36 are respectively installed on the first shell 1 and the fifth shell 5 through the leather bowl gland 37; the leather bowl 35 is in interference fit with the main shaft 6, and the single-side interference amount is 0.03-0.05mm.

[0053] The front liquid seal wheel 7 and the first shell 1, and the rear liquid seal wheel 34 and the fifth shell 5 are gap fit, and the key dimensions of the liquid seal wheel seal are as shown in the figure. Figure 2 The sealing pressure of the liquid seal wheel is calculated according to the following formula.

[0054]

[0055] In the formula, P is the impeller sealing pressure, n is the impeller rotating speed, D1 is the inner diameter of the liquid seal wheel blade, D2 is the outer diameter of the liquid seal wheel, p is the density of the sealing cavity test medium, g is the gravity acceleration, h is the height of the liquid seal wheel blade 23, and k is the back pressure coefficient, which is determined according to the structure and use conditions.

[0056] The inner diameters D1 of the blades of the front liquid seal wheel 7 and the rear liquid seal wheel 34 are the same, and the outer diameters D2 of the liquid seal wheels have different sizes; for the front liquid seal wheel 7, Figure 2 In the formula, L is the total axial length of the shell, H is the total axial length of the outer circle of the liquid seal wheel, and D3 is the inner hole diameter of the shell, so that D3-D2=1mm and L≥H+δ.

[0057] The end face seal I 16 and the front liquid seal wheel 7 form a sealing cavity I, the sealing pressure of which is recorded as P1, and the low-temperature medium enters through the first medium inlet; the circumferential segmented seal 18 forms a sealing cavity II inside, the sealing pressure of which is recorded as P2, and the normal-temperature gas medium enters through the second medium inlet; the end face seal II 19 and the rear liquid seal wheel 24 form a sealing cavity III, the sealing pressure of which is recorded as P3, and the low-temperature medium enters through the third medium inlet. The first medium inlet and the second medium inlet are the pipe mouths of the third shell, and the third medium inlet is the pipe mouth of the fourth shell. The circumferential segmented seal 18 and the end face seal I 16 form a leakage cavity I, and the circumferential segmented seal 18 and the end face seal II 19 form a leakage cavity II.

[0058] The sealable pressures of the front liquid seal wheel 7 and the rear liquid seal wheel 34 are respectively recorded as P前 , P 后 , the outer diameter of the front and rear liquid seal wheels 7, 34 are respectively recorded as D 2前 , D 2后 , when the pressure of the sealing cavity I and the pressure of the sealing cavity III are P1=P3, the axial force F 轴 generated by the front and rear ends of the main shaft is 0, then the outer diameter D 2前 of the front and rear liquid seal wheels 7, 34 is D 2后 , at this time the sealing pressure satisfies P 前 =P 后 ≤0.5MPa, and the axial force F 轮 generated by the front and rear liquid seal wheels 7, 34 is 0.

[0059] When the pressure of the sealing cavity I and the pressure of the sealing cavity III are P1≠P3, at this time the outer diameter D2 of the front and rear liquid seal wheels 7, 34 is selected to be different sizes, at this time P 前 =P 后 ≤P 气 , P 气 is the gasification pressure of liquid nitrogen under local atmospheric pressure. When P1>P3, at this time D 2前 >D 2后 , and the axial force F 轮 generated by the front and rear liquid seal wheels 7, 34 should be equal to the axial force F 轴 generated by the front and rear ends of the main shaft.

[0060] The principle of the medium supply system of the test device is shown in Figure 3 Fig. 4. For low-temperature medium: the low-temperature medium of the sealing cavity I and the sealing cavity III respectively passes through two low-temperature pressure containers 40 in turn, passes through low-temperature pneumatic stop valves 42, low-temperature manual stop valves 43, and low-temperature mass flow meters 44, and is supplied. The low-temperature medium enters the front bearing 10 and the rear bearing 23 after entering the sealing cavity I and the sealing cavity III, a part of which is discharged after passing through a low-temperature electric regulating valve 49, a part of which is discharged through the front liquid seal wheel 7, the rear liquid seal wheel 34 and the shaft seal after it, and finally a part of which enters the leakage cavity I and the leakage cavity II through the end face seal I 16 and the end face seal II 19 respectively, and finally is discharged through the gasifier 50 and the mass flow meter 51.

[0061] For nitrogen medium, the nitrogen medium in the nitrogen bottle group 41 passes through a manual stop valve 45, a pressure reducing valve 46, a normal-temperature mass flow meter 47, and a nozzle 48 in turn, and then enters the sealing cavity II, and then enters the leakage cavity I and the leakage cavity II through the circumferential segmented seal 18, and finally is discharged through the gasifier 50 and the mass flow meter 51.

[0062] The nozzle 48 mainly plays a role in throttling and pressure reduction of the upstream nitrogen, and can supply the real gas flow state after passing through the nozzle 48 to the circumferential segmented seal 18.

[0063] Although the present application has been disclosed with reference to the preferred embodiments, it is not intended to limit the present application to the preferred embodiments. Any person skilled in the art, without departing from the spirit and scope of the present application, can make possible changes and modifications to the technical solutions of the present application by using the disclosed methods and technical contents. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application, without departing from the technical solutions of the present application, shall fall within the protection scope of the technical solutions of the present application.

Claims

1. A liquid rocket engine turbopump combination sealing test device, characterized in that: The system includes a rotor assembly, a housing assembly, and a media supply system. A cryogenic end-face seal to be tested is fitted onto the rotor assembly with a certain compression, contacting the rotating ring of the rotor assembly. A circumferential segmented seal to be tested is fitted onto the rotor assembly, forming a sealing gap with the shaft sleeve of the rotor assembly. Both the end-face seal and the circumferential segmented seal are fixed to the housing assembly. Several sealing cavities and leakage cavities are formed between the end-face seal, the circumferential segmented seal, the housing assembly, and the rotor assembly. The media supply system communicates with the sealing cavities to provide cryogenic liquid media or room-temperature gas media to the sealing cavities. During the test, the rotor assembly rotates, and the end face seal to be tested contacts the dynamic ring to perform dynamic sealing on the sealing cavity. The gap between the circumferential segmented seal and the bushing forms a dynamic seal for the gas medium. The inlet flow rate of each sealing cavity and the leakage amount of each leakage cavity are monitored to obtain the sealing characteristics and working stability of the low temperature end face seal and the circumferential segmented seal. The housing assembly includes a first housing (1), a second housing (2), a third housing (3), a fourth housing (4), and a fifth housing (5); The first housing (1) side is designated as the front end, and the fifth housing (5) side is designated as the rear end; The rotor assembly includes a main shaft (6), a front liquid seal wheel (7), a rear liquid seal wheel (34), a front bearing (10), and a rear bearing (23); The front end of the main shaft (6) is fixedly mounted on the second housing (2) via a front bearing (10), and the rear end is fixedly mounted on the fourth housing (4) via a rear bearing (23). The rear end of the main shaft (6) is provided with spline teeth and the end of the shaft is provided with a threaded hole; the front end of the main shaft (6) is provided with speed measuring teeth and the end of the shaft is a planar structure. A displacement sensor is provided at the front end of the spindle (6) to monitor the axial vibration of the test device during high-speed operation and indirectly reflect the change of axial force of the test device; a speed measurement sensor is provided at the radial position of the front end of the spindle (6) to monitor the real-time speed of the test device during high-speed operation. The end face seal I (16) is installed at the front end of the third housing (3), and its compression is adjusted by the length of the front moving ring bushing (15); the circumferential segmented seal (18) is installed at the rear end of the third housing (3); the end face seal II (19) is installed at the front end of the fourth housing (4), and its compression is adjusted by the length of the rear moving ring bushing (20).

2. The liquid rocket engine turbopump combined sealing test device according to claim 1, characterized in that: The front liquid seal wheel (7) is threadedly installed at the front end of the main shaft (6), and the rear liquid seal wheel (34) is threadedly installed at the rear end of the main shaft (6). The threads of the front liquid seal wheel (7) and the rear liquid seal wheel (34) are opposite in direction. The front liquid seal wheel (7) is located between the first housing (1) and the front bearing, and the rear liquid seal wheel (34) is located between the fifth housing (5) and the rear bearing. The front shaft seal is installed on the main shaft and is located at the front end of the front liquid seal wheel. The rear shaft seal is installed on the main shaft and is located at the rear end of the rear liquid seal wheel. The front liquid seal wheel and the front shaft seal, and the rear liquid seal wheel and the rear shaft seal form a rotor shaft head combination seal. The end face seal I (16) and the front liquid seal wheel (7) form a sealing cavity I, the sealing pressure of which is denoted as P1, and the low-temperature medium enters through the first medium inlet; the circumferential segmented seal (18) forms a sealing cavity II, the sealing pressure of which is denoted as P2, and the normal temperature gas medium enters through the second medium inlet; the end face seal II (19) and the rear liquid seal wheel (34) form a sealing cavity III, the sealing pressure of which is denoted as P3, and the low-temperature medium enters through the third medium inlet; the first medium inlet and the second medium inlet are both the connectors of the third housing, and the third medium inlet is the connector of the fourth housing; A leakage cavity I is formed between the circumferential segmented seal (18) and the end face seal I (16), and a leakage cavity II is formed between the circumferential segmented seal (18) and the end face seal II (19).

3. The liquid rocket engine turbopump combination sealing test device according to claim 2, characterized in that: The outer ring of the front bearing (10) is fitted onto the front bearing outer sleeve (11), and the front bearing outer sleeve (11) is fixedly installed on the second housing (2) by bolts; the inner ring of the front bearing (10) is installed on the front bearing inner sleeve (9), and the inner ring and the front bearing inner sleeve (9) are fixed to the main shaft by the front bearing cap (8); the front end of the outer ring of the front bearing (10) contacts the first disc spring (261), the first disc spring (261) is installed on the first disc spring retainer (271), and is pressed and positioned by the front bearing cap (291) fixedly installed on the front bearing outer sleeve (11) and the front disc spring adjusting shim, and the front disc spring adjusting shim is installed between the first disc spring retainer (271) and the front bearing cap (291).

4. The liquid rocket engine turbopump combined sealing test device according to claim 3, characterized in that: The outer ring of the rear bearing (23) is fitted onto the rear bearing outer sleeve (25), and the rear bearing outer sleeve (25) is fixedly installed on the fourth housing (4) by bolts; the inner ring of the rear bearing (23) is installed on the rear bearing inner sleeve (24), and the inner ring and the rear bearing inner sleeve (24) are fixed to the main shaft (6) by the rear bearing cap (30); the rear end of the outer ring of the rear bearing (23) contacts the second disc spring (262), the second disc spring (262) is installed on the second disc spring retainer (272), and is positioned by the rear bearing cap (292) fixedly installed on the rear bearing outer sleeve (25) and the rear disc spring adjusting shim, and the rear disc spring adjusting shim is installed between the second disc spring retainer (272) and the rear bearing cap (292).

5. The liquid rocket engine turbopump combined sealing test device according to claim 4, characterized in that: The front bearing (10) and the front bearing outer sleeve (11), and the rear bearing (23) and the rear bearing outer sleeve (25) are all clearance fits. The materials of the front bearing outer ring and the front bearing outer sleeve (11), and the rear bearing outer ring and the rear bearing outer sleeve (25) are the same. The single-sided fit clearance at low temperature is 0.01 to 0.015 mm. The axial preload of the front bearing (10) is achieved by the compression of the first disc spring, and the axial preload of the rear bearing (23) is achieved by the compression of the second disc spring. The compression of the first disc spring is achieved by adjusting the front disc spring shim, and the compression of the second disc spring is achieved by adjusting the rear disc spring shim.

6. The liquid rocket engine turbopump combination sealing test device according to claim 2, characterized in that: Both the front and rear shaft seals are low-temperature cup contact seals.

7. The liquid rocket engine turbopump combined sealing test device according to claim 2, characterized in that: The total axial length H of the outer circles of the front liquid seal wheel (7) and the rear liquid seal wheel (34) is the same, and the inner diameter D1 of the blades is the same; the total axial length of the housing assembly is L, and the inner diameter of the housing assembly is D3, then D3-D 2前 =1mm, D3-D 2后 =1mm, where D 2前 D is the outer diameter of the front liquid seal wheel (7) blade. 2后 The outer diameter of the blade of the rear liquid seal wheel (34).

8. The liquid rocket engine turbopump combined sealing test device according to claim 2, characterized in that: The sealing pressures of the front liquid seal wheel (7) and the rear liquid seal wheel (34) are respectively denoted as P. 前 P 后 The outer diameter is denoted as D. 2前 D 2后 When the pressure in sealing cavity I and sealing cavity III is P1 = P3, the axial force F generated at the front and rear ends of the main shaft 轴 =0, then the outer diameter D of the front liquid seal wheel (7) and the rear liquid seal wheel (34) is 0. 2前 =D 2后 At this time, the sealing pressure satisfies P. 前 =P 后 ≤0.5MPa, the axial force F generated by the front liquid seal wheel (7) and the rear liquid seal wheel (34) 轮 =0.

9. The liquid rocket engine turbopump combined sealing test device according to claim 8, characterized in that: When the pressure in sealing cavity I and sealing cavity III is P1≠P3, the outer diameter D2 of the front liquid seal wheel (7) and the rear liquid seal wheel (34) are selected to be different sizes. 前 =P 后 ≤P 气 P 气 This is the vaporization pressure of liquid nitrogen at the local atmospheric pressure.

10. A liquid rocket engine turbopump assembly sealing test system based on the liquid rocket engine turbopump assembly sealing test device according to claim 1, characterized in that: Includes a first cryogenic pressure vessel, a second cryogenic pressure vessel, a nitrogen cylinder group, a cryogenic pneumatic shut-off valve, a cryogenic manual shut-off valve, a cryogenic mass flow meter, a manual shut-off valve, a pressure reducing valve, a normal temperature mass flow meter, a nozzle, a cryogenic electric regulating valve, a vaporizer, and a volumetric flow meter; The first cryogenic pressure vessel is connected to the sealing chamber I through the first pipeline, and the second cryogenic pressure vessel is connected to the sealing chamber III through the first pipeline. The first and second pipelines are respectively equipped with a cryogenic pneumatic shut-off valve, a cryogenic manual shut-off valve, and a cryogenic mass flow meter along the medium inflow direction. The cryogenic medium enters the sealing chamber I to cool the front bearing, and enters the sealing chamber III to cool the rear bearing. Then, part of the medium is discharged after passing through the cryogenic electric regulating valve, and part is discharged through the front liquid seal wheel (7), the rear liquid seal wheel (34) and their shaft seal. The last part enters the leakage chamber I through the end face seal I (16), enters the leakage chamber II through the end face seal II (19), and finally passes through the vaporizer and the mass flow meter in sequence to be discharged. The nitrogen cylinder group is connected to the sealed chamber II through a gas pipeline. A manual shut-off valve, a pressure reducing valve, a normal temperature mass flow meter, and a nozzle are installed in sequence on the gas pipeline. The nitrogen medium passes through the sealed chamber II and enters the leakage chamber I and leakage chamber II through the circumferential segmented seal (18) respectively. Finally, it is discharged through the vaporizer (50) and the mass flow meter (51) respectively.

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