A space turbine pump low-temperature bearing test loading device and loading method

Abstract

The application relates to the technical field of bearing testing, in particular to a space turbine pump low-temperature bearing test loading device and a loading method, which comprises a test shaft shell, a test bearing A, an axial loading gland, an axial loading piston cylinder shell, an axial loading piston, a variable-diameter piston cylinder shell, a variable-diameter piston cylinder piston, a vaporizer, a test bearing B, a liquid nitrogen pipeline, a nitrogen pipeline and a hydraulic oil pipeline; liquid nitrogen enters the test shaft shell, is fully cooled and is discharged, is converted into nitrogen gas through heat exchange of the vaporizer, is introduced into the variable-diameter piston cylinder shell through the nitrogen pipeline, generates compression on the hydraulic oil, the hydraulic oil is introduced into the inside of the axial loading piston cylinder shell to generate oil pressure and push the axial loading piston to move, the axial loading piston generates thrust on the axial loading gland, the axial loading gland completes thrust loading on the test bearing, an electric cylinder is directly used to apply push-pull force load on the variable-diameter piston rod, load fluctuation is compensated, and the test load is stable.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bearing test, in particular to a space turbine pump low-temperature bearing test loading device and a loading method. BACKGROUND

[0002] Low-temperature bearing test is an important means to evaluate the performance of bearings in low-temperature environment, mainly involving the test of bearing running stability, friction characteristics, load capacity and service life under low-temperature conditions.

[0003] In order to simulate the actual working condition of low-temperature bearing, liquid nitrogen is usually used as low-temperature medium for bearing test. The bearing test cavity is a closed structure, and the liquid nitrogen is circulated through the cavity supply and return joint. The test needs to simulate the working pressure of the bearing in the turbine pump, so there is usually cavity pressure during the test, usually ≤5MPa. The heat generated by the bearing during the test is unstable, which leads to uneven vaporization of liquid nitrogen inside the cavity, and the pressure of the cavity fluctuates greatly, which directly leads to the fluctuation of the nitrogen pressure after vaporization, and easily leads to unstable loading. SUMMARY

[0004] In order to solve the technical problems that the heat generated by the bearing during the test is unstable, which leads to uneven vaporization of liquid nitrogen inside the cavity, and the pressure of the cavity fluctuates greatly, which directly leads to the fluctuation of the nitrogen pressure after vaporization, and easily leads to unstable loading, the present application provides a space turbine pump low-temperature bearing test loading device to solve the above problems.

[0005] The technical scheme adopted by the present application to solve the above technical problems is as follows: a space turbine pump low-temperature bearing test loading device, comprising a test shaft shell, a test bearing A, an axial loading gland, an axial loading piston cylinder shell, an axial loading piston, a variable diameter piston cylinder shell, a variable diameter piston cylinder piston, a vaporizer, a test bearing B, a liquid nitrogen pipeline, a nitrogen pipeline and a hydraulic oil pipeline; the upper and lower ends of the vaporizer are connected with the test shaft shell and the variable diameter piston cylinder shell through the liquid nitrogen pipeline and the nitrogen pipeline respectively, the test bearing A and the test bearing B are oppositely installed inside the two sides of the test shaft shell, the liquid nitrogen enters the test shaft shell after being fully cooled from the liquid nitrogen pipeline, is converted into nitrogen gas by heat exchange in the vaporizer, and is introduced into the variable diameter piston cylinder shell through the nitrogen pipeline to push the variable diameter piston cylinder piston to compress the hydraulic oil at the bottom of the variable diameter piston cylinder shell, the hydraulic oil is introduced into the inside of the axial loading piston cylinder shell to generate oil pressure to push the axial loading piston to move, the axial loading piston generates a pushing force on the axial loading gland to complete the pushing force loading on the test bearing A and the test bearing B.

[0006] As a further optimization scheme of the above-mentioned space turbine pump low-temperature bearing test loading device, an inlet and outlet port for connecting the liquid nitrogen pipeline is arranged on the test shaft shell, and a test shaft cavity pressure sensor is arranged on the liquid nitrogen pipeline outlet port.

[0007] As a further optimization scheme of the above-mentioned space turbine pump low-temperature bearing test loading device, a variable-diameter piston cylinder gas phase pressure sensor is arranged on the nitrogen pipeline.

[0008] As a further optimization scheme of the above-mentioned space turbine pump low-temperature bearing test loading device, the test bearing A and the test bearing B are both sleeved and installed on the test shaft, and the test shaft is in clearance fit with the test shaft shell and can be relatively displaced in the test shaft shell.

[0009] As a further optimization scheme of the above-mentioned space turbine pump low-temperature bearing test loading device, the axial loading gland is arranged on one side of the outer ring end face of the test bearing B, and the axial loading gland is in clearance fit with the test shaft shell and can be relatively displaced in the test shaft shell.

[0010] As a further optimization scheme of the above-mentioned space turbine pump low-temperature bearing test loading device, the axial loading piston is in clearance fit with the axial loading piston cylinder shell and can be relatively displaced in the axial loading piston cylinder shell.

[0011] As a further optimization scheme of the above-mentioned space turbine pump low-temperature bearing test loading device, the variable-diameter piston cylinder piston is arranged in the variable-diameter piston cylinder shell and is in clearance fit with the variable-diameter piston cylinder shell.

[0012] As a further optimization scheme of the above-mentioned space turbine pump low-temperature bearing test loading device, the two ends of the hydraulic oil pipeline are respectively connected with the variable-diameter piston cylinder bottom flange and the axial loading piston cylinder end face flange, and an axial loading piston cylinder pressure sensor is arranged on the hydraulic oil pipeline.

[0013] As a further optimization scheme of the above-mentioned space turbine pump low-temperature bearing test loading device, an electric cylinder is arranged above the variable-diameter piston cylinder shell, the piston rod of the electric cylinder extends into the variable-diameter piston cylinder shell and abuts against the top end of the variable-diameter piston cylinder piston, and an electric cylinder thrust sensor is arranged on the piston rod of the electric cylinder.

[0014] A loading method for space turbine pump low-temperature bearing test, comprising the following steps,

[0015] S, liquid nitrogen is introduced into the test shaft shell through the liquid inlet arranged on the left and right sides of the test shaft shell, and the inner and outer rings of the test bearing A and the test bearing B in the shell are fully cooled, and the liquid is discharged through the liquid outlet;

[0016] S, the liquid nitrogen discharged from the step S passes through the test shaft cavity pressure sensor, and the test shaft cavity pressure sensor monitors the pressure inside the test shaft shell;

[0017] S, the liquid nitrogen of the test shaft cavity pressure sensor passes through the heat exchange in the vaporizer, the liquid nitrogen is converted into nitrogen gas, the nitrogen gas passes through the variable diameter piston cylinder gas phase pressure sensor and enters the variable diameter piston cylinder shell;

[0018] S, the piston rod of the electric cylinder directly abuts against the variable diameter piston cylinder piston, and the nitrogen gas at the top of the variable diameter piston cylinder shell jointly generates pressure on the variable diameter piston cylinder piston, pushes the variable diameter piston cylinder piston to move downward, and compresses the hydraulic oil at the bottom of the variable diameter piston cylinder shell;

[0019] S, the hydraulic oil at the bottom of the variable diameter piston cylinder shell is compressed into the axial loading piston cylinder shell, and pushes the axial loading piston to move, the axial loading piston generates a pushing force on the axial loading gland, and the axial loading gland completes the thrust loading on the test bearing A and the test bearing B.

[0020] Compared with the prior art, the beneficial effects of the present application are:

[0021] 1. When the axial loading piston of the present application works, the inside of the loading piston cylinder is filled with hydraulic oil, the outside of the loading piston is connected with the test cavity, the inside of the test cavity is filled with liquid nitrogen, the liquid nitrogen contacts the outer surface of the loading piston, the hydraulic oil contacts the inner surface of the loading piston, the liquid nitrogen and the hydraulic oil exchange heat through the piston, and the liquid nitrogen rapidly vaporizes on the outer surface of the piston to form a gas film during the heat exchange process, the gas film can support the outer surface of the loading piston, reduce the working friction of the piston, and improve the test loading accuracy.

[0022] 2. During the test, the heat generation of the bearing is unstable, which leads to uneven vaporization of the liquid nitrogen in the cavity, large pressure fluctuation of the cavity, and large pressure fluctuation of the nitrogen gas after vaporization, which easily leads to unstable loading. To solve the above problems, an electric cylinder is used to directly apply a pushing and pulling force load to the variable diameter piston rod, the load fluctuation is compensated, and the test load is stabilized. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a sectional structure schematic diagram of the present application;

[0024] Figure 2 It is a liquid nitrogen, nitrogen gas and hydraulic oil path schematic diagram;

[0025] Figure 3 It is a schematic diagram of the pressure and pressure position of each part;

[0026] The markings in the diagram are: 1. Test shaft, 2. Test shaft sealing ring, 3. Test shaft housing, 4. Test bearing A, 5. Axial loading gland, 6. Test shaft housing flange sealing ring, 7. Test shaft housing flange, 8. Axial loading piston cylinder housing sealing ring, 9. Axial loading piston cylinder housing, 10. Axial loading piston sealing ring, 11. Axial loading piston, 12. Axial loading piston cylinder end face flange, 13. Axial loading piston cylinder pressure sensor, 14. Variable diameter piston cylinder bottom flange, 15. Variable diameter piston cylinder housing, 16. Variable diameter piston cylinder piston small end sealing ring, 17. Variable diameter piston cylinder piston, 18. Variable diameter piston cylinder piston large end sealing ring, 19. Variable diameter piston cylinder top flange, 20. Variable diameter piston cylinder top flange sealing ring, 21. Electric cylinder thrust sensor, 22. Electric cylinder, 23. Variable diameter piston cylinder gas phase pressure sensor, 24. Carburetor, 25. Test shaft cavity pressure sensor, 26. Test bearing B. Detailed Implementation

[0027] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0028] like Figure 1 As shown, a cryogenic bearing test loading device for aerospace turbopumps includes a test shaft housing 3, a test bearing A4, an axial loading gland 5, an axial loading piston cylinder housing 9, an axial loading piston 11, a variable-diameter piston cylinder housing 15, a variable-diameter piston cylinder piston 17, a vaporizer 24, a test bearing B26, a liquid nitrogen pipeline, a nitrogen pipeline, and a hydraulic oil pipeline. The test shaft housing 3 is provided with inlet and outlet ports for connecting the liquid nitrogen pipeline, and a test shaft cavity pressure sensor 25 is provided on the outlet port of the liquid nitrogen pipeline. A variable-diameter piston cylinder gas phase pressure sensor 23 is provided on the nitrogen pipeline. The test bearing A4 and the test bearing B26 are both sleeved and installed on the test shaft 1, and the test shaft 1 and the test shaft housing 3 are clearance-fitted and can be relatively displaced within the test shaft housing 3. The upper and lower ends of the vaporizer 24 are connected to the test shaft housing 3 and the variable-diameter piston cylinder housing 15 respectively through the liquid nitrogen pipeline and the nitrogen pipeline. The test bearing A4 and the test bearing B26 are installed opposite each other on both sides inside the test shaft housing 3.

[0029] The axial loading gland 5 is disposed on one side of the outer ring end face of the test bearing B26. The axial loading gland 5 is clearance-fitted with the test shaft housing 3 and can be relatively displaced within the test shaft housing 3. The axial loading piston 11 is clearance-fitted with the axial loading piston cylinder housing 9 and can be relatively displaced within the axial loading piston cylinder housing 9. The variable diameter piston cylinder piston 17 is disposed within the variable diameter piston cylinder housing 15 and is clearance-fitted with the variable diameter piston cylinder housing 15.

[0030] The two ends of the hydraulic oil pipeline are connected with the variable-diameter piston cylinder bottom flange 14 and the axial loading piston cylinder end face flange 12 respectively, and the hydraulic oil pipeline is provided with an axial loading piston cylinder pressure sensor 13.

[0031] The variable-diameter piston cylinder shell 15 is provided above with an electric cylinder 22, the piston rod of the electric cylinder 22 extends into the variable-diameter piston cylinder shell 15 and abuts against the top end of the variable-diameter piston cylinder piston 17, and the piston rod of the electric cylinder 22 is provided with an electric cylinder thrust sensor 21.

[0032] As shown in Figure 2 and Figure 3 A loading method for a space turbine pump low-temperature bearing test, comprising the following steps,

[0033] S1, liquid nitrogen is introduced into the test shaft shell 3 through the liquid inlet arranged on the left and right sides of the test shaft shell 3, and the inner and outer rings of the test bearing A 4 and the test bearing B 26 inside the shell are fully cooled, and the liquid is discharged through the liquid outlet;

[0034] S2, the liquid nitrogen discharged from the step S1 passes through the test shaft cavity pressure sensor 25, and the test shaft cavity pressure sensor 25 monitors the pressure inside the test shaft shell 3;

[0035] S3, the liquid nitrogen passing through the test shaft cavity pressure sensor 25 enters the heat exchanger 24 to be heat-exchanged, and the liquid nitrogen is converted into nitrogen gas, which is introduced into the variable-diameter piston cylinder shell 15 through the variable-diameter piston cylinder gas phase pressure sensor 23;

[0036] S4, the piston rod of the electric cylinder 22 directly abuts against the variable-diameter piston cylinder piston 17, and the nitrogen gas at the top of the variable-diameter piston cylinder shell 15 together generates pressure on the variable-diameter piston cylinder piston 17, pushes the variable-diameter piston cylinder piston 17 to move downward, and compresses the hydraulic oil at the bottom of the variable-diameter piston cylinder shell 15;

[0037] S5, the hydraulic oil at the bottom of the variable-diameter piston cylinder shell 15 is compressed to enter the axial loading piston cylinder shell 9, and pushes the axial loading piston 11 to move, the axial loading piston 11 generates a thrust on the axial loading gland 5, and promotes the axial loading gland 5 to complete the thrust loading on the test bearing A 4 and the test bearing B 26.

[0038] In Figure 1 , the letter A represents the diameter of the variable-diameter piston cylinder, the letter B represents the diameter of the variable-diameter piston cylinder piston rod, the letter C represents the diameter of the axial loading piston cylinder, and the letter D represents the diameter of the test shaft,

[0039] The discharged liquid nitrogen first passes through a pressure gauge P3 (test shaft cavity pressure), and then through a tee joint, a part of which is branched to the vaporizer 24, and is vaporized into nitrogen gas with a pressure of about 1-5 MPa through the vaporizer 24, and finally enters the variable-diameter piston cylinder through the pressure gauge P1 (variable-diameter piston cylinder gas phase pressure), and the output hydraulic oil is pressurized through the variable-diameter piston rod, and the pressurized hydraulic oil enters the test loading cylinder through P2 (test loading cylinder pressure).

[0040] The P3 pressure is the test shaft cavity pressure, and the bearing heat during the test process is unstable, which leads to uneven vaporization of the liquid nitrogen in the cavity, and the P3 cavity pressure fluctuates greatly, which directly leads to large fluctuation of the nitrogen gas pressure P1 after vaporization, and easily leads to unstable loading. In view of the above problems, an electric cylinder is used to directly apply a push-pull force load to the variable-diameter piston rod to compensate for the load fluctuation.

[0041] The thrust generated by the cavity pressure P3 on the test bearing A is represented as:

[0042] ,

[0043] The thrust generated by the large end pressure P1 of the variable-diameter piston cylinder piston is represented as:

[0044] ,

[0045] The small end pressure P2 of the variable-diameter piston cylinder piston is represented as:

[0046] ,

[0047] The axial loading piston thrust F 轴向加载活塞 is represented as:

[0048] ,

[0049] The actual force F 试验轴承A of the test bearing A is represented as:

[0050] ,

[0051] The actual force F 试验轴承B of the test bearing B is represented as:

[0052] .

[0053] According to the above calculation, the actual thrust of the test bearing A during the test process can be obtained; at the same time, the required compensation force of the electric cylinder can be calculated through the formula under the unstable load condition, and the load is compensated to ensure stable test load.

[0054] The preferred embodiments and examples of the present application are described in detail above in conjunction with the accompanying drawings, but the present application is not limited to the above-described embodiments and examples, and various changes can be made within the knowledge of those skilled in the art without departing from the concept of the present application.

Claims

1. A loading device for testing cryogenic bearings of aerospace turbopumps, characterized in that: The test shaft housing includes a test bearing A (4), an axial loading gland (5), an axial loading piston cylinder housing (9), an axial loading piston (11), a variable diameter piston cylinder housing (15), a variable diameter piston cylinder piston (17), a vaporizer (24), a test bearing B (26), liquid nitrogen pipelines, nitrogen pipelines, and hydraulic oil pipelines. The test bearing A (4) and the test bearing B (26) are installed opposite each other on both sides inside the test shaft housing (3). Liquid nitrogen is introduced into the test shaft housing (3) through the inlets located on the left and right sides of the test shaft housing (3) to fully cool the inner and outer rings of the test bearing A (4) and the test bearing B (26) inside the housing. The liquid nitrogen is introduced into the test shaft housing (3) through the inlets located on the left and right sides of the test shaft housing (3) to fully cool the inner and outer rings of the test bearing A (4) and the test bearing B (26) inside the housing. The liquid nitrogen is discharged from the outlet; the discharged liquid nitrogen first passes through the test shaft cavity pressure sensor (25), and then through the three-way valve, part of which is diverted to the vaporizer (24), and the other part is discharged; the liquid nitrogen is converted into nitrogen gas by heat exchange in the vaporizer (24), and then enters the variable diameter piston cylinder housing (15) through the nitrogen gas pipeline, which pushes the variable diameter piston cylinder piston (17) to compress the hydraulic oil at the bottom of the variable diameter piston cylinder housing (15), and the hydraulic oil enters the axial loading piston cylinder housing (9) to generate oil pressure to push the axial loading piston (11) to move, and the axial loading piston (11) generates thrust on the axial loading cover (5), which causes the axial loading cover (5) to complete the thrust loading on the test bearing A (4) and the test bearing B (26); The axial loading cover (5) is located on one side of the outer ring end face of the test bearing B (26). The axial loading cover (5) is clearance-fitted with the test shaft housing (3) and can be relatively displaced within the test shaft housing (3).

2. The aerospace turbopump cryogenic bearing test loading device as described in claim 1, characterized in that: A variable-diameter piston cylinder gas phase pressure sensor (23) is installed on the nitrogen pipeline.

3. The aerospace turbopump cryogenic bearing test loading device as described in claim 1, characterized in that: The test bearings A (4) and B (26) are both mounted on the test shaft (1). The test shaft (1) is clearance-fitted with the test shaft housing (3) and can be displaced relative to each other within the test shaft housing (3).

4. The aerospace turbopump cryogenic bearing test loading device as described in claim 1, characterized in that: The axially loaded piston (11) is clearance-fitted with the axially loaded piston cylinder housing (9) and can be relatively displaced within the axially loaded piston cylinder housing (9).

5. The aerospace turbopump cryogenic bearing test loading device as described in claim 1, characterized in that: The piston (17) of the variable diameter piston cylinder is disposed inside the variable diameter piston cylinder housing (15) and is clearance-fitted with the variable diameter piston cylinder housing (15).

6. The aerospace turbopump cryogenic bearing test loading device as described in claim 1, characterized in that: The two ends of the hydraulic oil pipeline are connected to the bottom flange (14) of the variable diameter piston cylinder and the end face flange (9) of the axially loaded piston cylinder, respectively, and an axially loaded piston cylinder pressure sensor (13) is installed on the hydraulic oil pipeline.

7. A cryogenic bearing test loading device for aerospace turbopumps as described in any one of claims 1 to 6, characterized in that: An electric cylinder (22) is provided above the variable diameter piston cylinder housing (15). The piston rod of the electric cylinder (22) extends into the variable diameter piston cylinder housing (15) and abuts against the top of the variable diameter piston cylinder piston (17). An electric cylinder thrust sensor (21) is provided on the piston rod of the electric cylinder (22).

8. A loading method using the aerospace turbopump cryogenic bearing test loading device as described in claim 7, characterized in that: Includes the following steps, S1, liquid nitrogen is introduced into the test shaft housing (3) through the inlet ports set on the left and right sides of the test shaft housing (3) to fully cool the inner and outer rings of the test bearing A (4) and test bearing B (26) inside the housing, and is discharged from the outlet port; S2, the liquid nitrogen discharged from step S1 passes through the test shaft cavity pressure sensor (25), and the test shaft cavity pressure sensor (25) monitors the internal pressure of the test shaft housing (3); S3, a portion of the liquid nitrogen passing through the test shaft cavity pressure sensor (25) enters the vaporizer (24) for heat exchange, and the liquid nitrogen is converted into nitrogen gas. The nitrogen gas passes through the variable diameter piston cylinder gas phase pressure sensor (23) and enters the variable diameter piston cylinder housing (15). S4, the piston rod of the electric cylinder (22) directly abuts against the piston (17) of the variable diameter piston cylinder, and together with the nitrogen gas at the top of the variable diameter piston cylinder housing (15), it exerts pressure on the piston (17) of the variable diameter piston cylinder, pushing the piston (17) of the variable diameter piston cylinder to move downward and compressing the hydraulic oil at the bottom of the variable diameter piston cylinder housing (15). S5, the hydraulic oil at the bottom of the variable diameter piston cylinder housing (15) is compressed and enters the axial loading piston cylinder housing (9), and pushes the axial loading piston (11) to move. The axial loading piston (11) generates thrust on the axial loading cover (5), causing the axial loading cover (5) to complete the thrust loading on the test bearing A (4) and the test bearing B (26).

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