System for measuring flow state of lubricating oil in bearing cavity of aero-engine

Abstract

The invention relates to the field of aero-engine bearing cavity structure system testing, and particularly provides an aero-engine bearing cavity inner lubricating oil flow state measuring system which comprises a test piece main body simulating an aero-engine bearing cavity, an oil gas supply and recovery system and a control system. The test piece main body comprises a rotor test piece and a stator test piece which are connected together, and the oil gas supply and recovery system comprises an oil supply system, a gas supply system, an oil return pool and an oil gas separation pump. The control system comprises a controller, and an oil supply throttle valve, an air supply throttle valve, an exhaust throttle valve, a test data acquisition assembly and a test piece main body driving device which are in signal connection with the controller. On the basis of the method, the lubricating oil-air flowing state in the bearing cavity can be monitored and evaluated in real time, and test support can be provided for follow-up bearing cavity optimization design.

Description

Technical Field

[0001] The present invention relates to the field of tests for the bearing cavity structure system of an aero-engine, and particularly provides a measuring system for the flow state of lubricating oil in the bearing cavity of an aero-engine. Background Art

[0002] The main bearing of an aero-engine is one of the key components of the engine, which is used to restrict the movement of the rotor and transmit the loads generated by the rotor. Its safe operation is crucial for the stable and reliable operation of the engine. In order to reduce the damage during the operation of the bearing, the bearing cavity provides a necessary space for the bearing, and a large amount of lubricating oil is used to lubricate and cool the bearing in the cavity, thereby suppressing the local frictional heat generation of the bearing and ensuring the stable and reliable operation of the bearing. Therefore, whether the bearing cavity is reasonably designed is crucial for controlling bearing damage and improving the reliability of the rotor-bearing system and even the entire engine. In the bearing cavity structure system, it includes both a solid domain composed of components such as the rotor, stator, and bearing and their connection interfaces, and a fluid domain composed of oil-gas multiphase fluids in the bearing cavity. The two affect each other, and the process is extremely complex, which brings challenges to the analysis and optimization of the bearing cooling and lubrication effect in the bearing cavity. In addition to theoretical simulation, conducting an oil-gas flow test in the aero-engine bearing cavity is also an important means to obtain the oil-gas flow state in the bearing cavity, judge whether the bearing cavity design is reasonable, and obtain key design parameters.

[0003] However, when conducting the oil-gas flow test in the bearing cavity, since the bearing cavity is wrapped by components, the oil-gas flow state therein cannot be directly observed. At the same time, the bearing cavity is a complex oil-gas two-phase flow, and traditional fluid velocity sensors and pressure sensors that are only applicable to single-phase flow cannot be used for measurement. As a result, the flow state of the lubricating oil-air in the bearing cavity during the test is unclear. Correspondingly, it is also impossible to directly reveal how the geometric configuration and load environment of the bearing cavity affect the oil-gas flow and ultimately how they affect the bearing cooling and lubrication effect in the bearing cavity based on the test, making the test unable to be directly used to guide the optimization design of the bearing cavity. Therefore, the traditional test method in the bearing cavity that can only indirectly evaluate the lubricating oil flow state in the bearing cavity by relying on a small number of parameters such as the lubricating oil flow rate / pressure at the inlet and outlet gradually shows limitations.

[0004] In response to the above needs, it is necessary to design an experimental measurement method that can obtain the flow state of lubricating oil-air in the bearing cavity under working conditions. This is the method basis for revealing the oil-gas flow state in the bearing cavity and its key influencing factors, and can provide experimental support for the subsequent optimization design of the bearing cavity. Summary of the Invention

[0005] To solve the above technical problems, the present invention provides a measurement system for the lubricating oil flow state inside the bearing chamber of an aero-engine, which can observe the oil-gas distribution state and liquid level height in the oil return pool and the rear half area of the bearing chamber through a transparent window, and supplemented by a variety of measurement data, quantitatively evaluate the oil-gas flow state inside the bearing chamber.

[0006] The present invention is implemented as follows. A measurement system for the lubricating oil flow state inside the bearing chamber of an aero-engine is provided, which includes a test piece main body simulating the bearing chamber of an aero-engine, an oil-gas supply and recovery system, and a control system. The test piece main body includes a rotor test piece and a stator test piece connected together. The oil-gas supply and recovery system includes an oil supply system, a gas supply system, an oil return pool, and an oil-gas separation pump. The oil supply system is connected to the oil circuit inlet in the test piece main body, and the oil circuit outlet is connected to the oil return pool. The gas supply system is connected to the gas circuit inlet in the test piece main body, and the gas circuit outlet is also connected to the oil return pool. The oil return pool is connected to the oil-gas separation pump. The control system includes a controller and an oil supply throttle valve, a gas supply throttle valve, an exhaust throttle valve, a test data acquisition component, and a test piece main body driving device that are signal-connected to the controller. The oil supply throttle valve is arranged on the pipeline connecting the oil supply system and the test piece main body. The gas supply throttle valve is arranged on the pipeline connecting the gas supply system and the test piece main body. The exhaust throttle valve is arranged on the pipeline connecting the oil return pool and the oil-gas separation pump. The oil-gas separation pump is also connected to the controller. The test data acquisition component is arranged at the position where data is to be acquired.

[0007] Preferably, the rotor test piece includes a simulated front shaft of the low-pressure turbine, a 1# bearing, a 2# bearing, a 5# bearing, a compression bushing, an inner seal housing, an outer seal housing, a simulated low-pressure turbine disk shaft, a graphite seal inner ring, a sliding seal ring, and an oil collecting bushing. Among them, the 1# bearing, the 2# bearing, and the compression bushing are sleeved on the front section of the simulated front shaft of the low-pressure turbine and locked by a first nut. The rear section of the simulated front shaft of the low-pressure turbine is connected to the front section of the simulated low-pressure turbine disk shaft through a flange-bolt connection structure. The inner seal housing, the outer seal housing, and the graphite seal inner ring are all connected to the simulated low-pressure turbine disk shaft. The rotating body of the 5# bearing is locked to the simulated low-pressure turbine disk shaft by a second nut. The sliding seal ring is pressed into the oil collecting bushing and connected to the simulated low-pressure turbine disk shaft by screws.

[0008] Further preferably, the stator test piece includes a low-pressure turbine front bearing housing, a transfer plate, a load-bearing housing, a simulated high-pressure rear journal, a high-pressure labyrinth bushing, an integrated housing, a graphite sealing outer ring, a bearing outer ring, an oil nozzle, a rear seal housing, a side cover baffle, an oil sump side cover, a rear baffle, a bearing cavity rear end cover, and a transfer housing. Among them, the low-pressure turbine front bearing housing is connected to the transfer plate fixed on the load-bearing housing; the trailing edge of the integrated housing is connected to the transfer housing; the high-pressure labyrinth bushing and the simulated high-pressure rear journal are locked tightly by a third large nut; both the graphite sealing outer ring and the bearing outer ring are connected to the integrated housing; the oil sump side cover is pressed tightly on the integrated housing by the side cover baffle with screws; the oil nozzle and the rear seal housing are connected by bolts; the bearing cavity rear end cover is located in the empty slot between the rear seal housing and the rear baffle, locked tightly by screws, and connected to the integrated housing by bolts.

[0009] Further preferably, the simulated low-pressure turbine front shaft in the rotor test piece passes through the simulated high-pressure rear journal in the stator test piece and inserts into the low-pressure turbine front bearing housing, and the axial displacement between components is restricted by a circlip.

[0010] Further preferably, an oil sump viewing window is provided on the oil sump side cover of the stator test piece, and a rear end cover viewing window is provided on the bearing cavity rear end cover. A camera is provided at the outer position of the oil sump viewing window and the rear end cover viewing window, and the camera is connected to the controller.

[0011] Preferably, the test data acquisition component includes an oil leakage amount acquisition unit, a bearing cavity pressure acquisition unit, an oil supply amount acquisition unit, an oil recovery amount acquisition unit, an air flow acquisition unit, and an oil supply flow acquisition unit, all of which are connected to the controller.

[0012] Compared with the prior art, the advantages of the present invention are as follows:

[0013] (1) In the present invention, the oil-gas distribution state and liquid level height in the oil sump and the rear half area of the bearing cavity can be observed through the transparent viewing window; and the whole process of oil-gas flow in the bearing cavity during the test is recorded by the photographic equipment.

[0014] (2) In the present invention, the test data acquisition system measures and collects data such as the oil return amount, air flow, and oil leakage amount of the lubricating oil, and quantitatively analyzes and evaluates the lubricating oil flow process. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The following further describes the present invention in detail in conjunction with the drawings and embodiments:

[0016] Figure 1 is a three-dimensional sectional view of the test piece;

[0017] Figure 2 is a schematic structural composition diagram of the rotor test piece;

[0018] Figure 3 Schematic diagram of the structure composition of the stator test piece;

[0019] Figure 4 Schematic diagrams of the front (a) and rear (b) windows of the bearing chamber;

[0020] Figure 5 Schematic diagram of the working principle of the accessory system of the test piece;

[0021] Figure 6 Schematic diagram of the oil and gas circuit distribution in the bearing chamber during the test;

[0022] Figure 7 Schematic diagram of the working process of the lubricating oil supply and recovery system. Specific implementation manners

[0023] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0024] As Figure 1 shown, the embodiment of the present invention relates to a measurement system for the flow state of lubricating oil in an aero-engine bearing chamber. The main body of the test piece includes a rotor test piece 101 and a stator test piece 102; in addition to the main body of the test piece, an oil and gas supply and recovery system and a control system are also required to jointly form a principle tester.

[0025] First, the structure of the main body of the test piece of the present invention will be described in detail with reference to the accompanying drawings:

[0026] As Figure 2 shown, in the embodiment of the present invention, the rotor test piece 101 includes a simulated front shaft of the low-pressure turbine 205, a 1# bearing 202, a 2# bearing 204, a 5# bearing 210, a compression bushing 203, an inner seal housing 206, an outer seal housing 207, a simulated low-pressure turbine disk shaft 208, a graphite seal inner ring 209, a sliding seal ring 212, and an oil collecting bushing 213. Among them, the 1# bearing 202, the 2# bearing 204, and the compression bushing 203 are sleeved on the front section of the simulated front shaft of the low-pressure turbine 205 and locked by a first large nut 201; the rear section of the simulated front shaft of the low-pressure turbine 205 is connected to the front section of the simulated low-pressure turbine disk shaft 205 through a flange-bolt connection structure; among them, the inner seal housing 206, the outer seal housing 207, and the graphite seal inner ring 209 are all connected to the simulated low-pressure turbine disk shaft 208; the rotating body of the 5# bearing 210 is locked to the simulated low-pressure turbine disk shaft 208 by a second large nut 211; the sliding seal ring 212 is pressed into the oil collecting bushing 213 and connected to the low-pressure turbine disk shaft 208 by screws.

[0027] As Figure 3As shown in the figure, the stator test piece 102 in the present invention includes a low-pressure turbine front bearing housing 301, an adapter plate 303, a load-bearing frame 304, a simulated high-pressure rear journal 305, a high-pressure labyrinth bush 306, an integrated housing 308, a graphite seal outer ring 309, a bearing outer ring 310, an oil nozzle 311, a rear seal housing 312, a side cover baffle 313, an oil sump side cover 314, a rear baffle 315, a bearing cavity rear end cover 316, and an adapter housing 317. The low-pressure turbine front bearing housing 301 is connected to the adapter plate 303 fixed on the load-bearing frame 304; the trailing edge of the integrated housing 308 is connected to the adapter housing 317; the high-pressure labyrinth bush 306 and the simulated high-pressure rear journal 305 are locked by a third large nut 307; both the graphite seal outer ring 309 and the bearing outer ring 310 are connected to the integrated housing 308; the oil sump side cover 314 is pressed against the integrated housing 308 by the side cover baffle 313 with screws; the oil nozzle 311 and the rear seal housing 312 are connected by bolts; the bearing cavity rear end cover 316 is located in the empty slot between the rear seal housing 312 and the rear baffle 315, locked by screws, and connected to the integrated housing 308 by bolts.

[0028] Among them, the simulated low-pressure turbine front shaft 205 in the rotor test piece 101 passes through the simulated high-pressure rear journal 305 in the stator test piece 102, inserts into the low-pressure turbine front bearing housing 301, and restricts the axial displacement between components through a circlip 302.

[0029] Furthermore, a visualization design is adopted for the bearing cavity. There are two transparent windows in the stator test piece 102, as Figure 4 shown, which are respectively: an oil sump window 401 located on the oil sump side cover 314, and a rear end cover window 402 located on the bearing cavity rear end cover 316. Through the transparent windows, the oil-gas distribution state and liquid level height in the oil sump and the rear half area of the bearing cavity can be observed. During the test process, a photographic device is arranged near the transparent windows to record the oil-gas flow state in the bearing cavity in real time.

[0030] Furthermore, in order to carry out the oil-gas flow test in the bearing cavity and evaluate the oil-gas flow state using the measurement system, the main body of the test piece needs to cooperate with the oil-gas supply and recovery system and the control system to work. The working principles of the oil-gas supply and recovery system and the control system are as Figure 5 、 6As shown in FIGS. 6 and 7, the controller 601 adjusts the throttle valves connected to the oil supply system 501 and the air supply system 502 according to the test requirements and feedback information to control the flow rates of the lubricating oil and the high-pressure air entering the bearing chamber, thereby controlling the pressure in the bearing chamber. Further, the oil return pump extracts the lubricating oil from the bearing chamber. The lubricating oil enters the oil return tank 503, and the lubricating oil and air are separated by the oil-gas separation pump 504. The lubricating oil is recovered and the air is discharged. Further, key parameters such as the lubricating oil leakage rate, the pressure in the bearing chamber, the lubricating oil recovery amount, and the air flow rate during the test are measured by the lubricating oil leakage rate acquisition unit 701, the bearing chamber pressure acquisition unit 702, the lubricating oil recovery amount acquisition unit 704, and the air flow rate acquisition unit 705 in the test data acquisition assembly respectively, and the data is fed back to the controller 6001 for adjusting the throttle valves of the oil supply system 501 and the air supply system 502 in real time to optimize the test conditions.

[0031] Further, Figure 6 FIG. 8 is a schematic diagram of the oil and gas circuit distribution in the bearing chamber during the test. The oil circuit is responsible for delivering the high-pressure lubricating oil to each lubricated part, and the gas circuit is responsible for delivering the high-pressure sealing gas to prevent the lubricating oil from leaking. Immediately afterwards, the lubricating oil flowing back from each part is collected through the oil return tank 503 and then sent back to the lubricating oil tank by the oil return pump. The lubricating oil in the lubricating oil tank is transported to the main body of the test piece again through the lubricating oil supply pump to realize the recycling of the lubricating oil. Among them, an exhaust throttle valve 604 and an oil supply throttle valve 602 are arranged at the position shown in Figure 7 FIG. 9, a pressure sensor is arranged in the chamber as the bearing chamber pressure acquisition unit 702, an oil return flowmeter is arranged between the oil-gas separation pump 504 and the lubricating oil tank as the lubricating oil recovery amount acquisition unit 704, and an oil supply flowmeter is arranged between the lubricating oil supply pump and the oil supply throttle valve 602 as the lubricating oil supply amount acquisition unit 703. These components facilitate the real-time monitoring and recording of key parameters such as the pressure in the bearing chamber and the lubricating oil flow rate. Finally, the quantitative evaluation of the oil and gas flow state in the chamber is carried out by using the data collected by the test data acquisition assembly and combining with the oil and gas flow process recorded by the camera.

[0032] The embodiments described above are only descriptions of the preferred modes of the present invention and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations, variations, modifications, and substitutions made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A system for measuring the flow state of lubricating oil in a bearing cavity of an aircraft engine, characterized in that: The invention comprises a test piece body simulating an aircraft engine bearing cavity, an oil and gas supply and recovery system and a control system. The test piece body comprises a rotor test piece (101) and a stator test piece (102) connected together. The oil and gas supply and recovery system comprises an oil supply system (501), an air supply system (502), an oil return pool (503) and an oil and gas separation pump (504). The oil supply system (501) is connected to an oil circuit inlet in the test piece body, and an oil circuit outlet is connected to the oil return pool (503). The air supply system (502) is connected to an air circuit inlet in the test piece body, and an air circuit outlet is also connected to the oil return pool (503). The oil return pool (503) is connected to the oil and gas separation pump (504). The control system comprises a control The invention relates to a device (601) and an oil supply throttle valve (602), an air supply throttle valve (603), an exhaust throttle valve (604), a test data acquisition component and a test piece main body driving device (605) which are connected to the controller (601) by signals. The oil supply throttle valve (602) is arranged on a pipeline connecting the oil supply system (501) and the test piece main body. The air supply throttle valve (603) is arranged on a pipeline connecting the air supply system (502) and the test piece main body. The exhaust throttle valve (604) is arranged on a pipeline connecting the oil return pool (503) and the oil-gas separation pump (504). The oil-gas separation pump (504) is also connected to the controller (601). The test data acquisition component is arranged at a position where data is to be collected.

2. The system for measuring the flow state of lubricating oil in the bearing cavity of an aircraft engine according to claim 1, characterized in that: The rotor test piece (101) comprises a simulated low-pressure turbine front shaft (205), a No. 1 bearing (202), a No. 2 bearing (204), a No. 5 bearing (210), a clamping bushing (203), an inner sealing shell (206), an outer sealing shell (207), a simulated low-pressure turbine disc shaft (208), a graphite sealing inner ring (209), a sliding sealing ring (212), and an oil collecting bushing (213); wherein the No. 1 bearing (202), the No. 2 bearing (204), and the clamping bushing (203) are inserted into the front section of the simulated low-pressure turbine front shaft (205), and a first The nut (201) is locked; the rear section of the simulated low-pressure turbine front shaft (205) is connected to the front section of the simulated low-pressure turbine disc shaft (208) through a flange-bolt connection structure; the inner sealing shell (206), the outer sealing shell (207), and the graphite sealing inner ring (209) are all connected to the simulated low-pressure turbine disc shaft (208); the rotating body of the 5# bearing (210) is locked with the simulated low-pressure turbine disc shaft (208) through a second nut (211); the sliding sealing ring (212) is pressed into the oil collecting bushing (213) and connected to the simulated low-pressure turbine disc shaft (208) through screws.

3. The system for measuring the flow state of lubricating oil in the bearing cavity of an aircraft engine according to claim 2, characterized in that: The stator test piece (102) comprises a low-pressure turbine front bearing frame (301), an adapter plate (303), a bearing frame (304), a simulated high-pressure rear journal (305), a high-pressure comb bushing (306), an integrated shell (308), a graphite sealing outer ring (309), a bearing outer ring (310), a lubricating oil nozzle (311), a rear sealing shell (312), a side cover baffle (313), an oil return pool side cover (314), a rear baffle (315), a bearing cavity rear end cover (316), and an adapter shell (317), wherein the low-pressure turbine front bearing frame (301) is connected to the adapter plate (303) fixed on the bearing frame (304); the integrated shell (308) is a graphite sealing outer ring (309), a bearing outer ring (310), a lubricating oil nozzle (311), a rear sealing shell (312), a side cover baffle (313), an oil return pool side cover (314), a rear baffle (315), a bearing cavity rear end cover (316), and an adapter shell (317). The rear edge of the shell (308) is connected to the adapter shell (317); the high-pressure comb bushing (306) and the simulated high-pressure rear journal (305) are locked by the third large nut (307); the graphite sealing outer ring (309) and the bearing outer ring (310) are connected to the integrated shell (308); the oil return pool side cover (314) is pressed to the integrated shell (308) by screws through the side cover baffle (313); the lubricating oil nozzle (311) and the rear sealing shell (312) are connected by bolts; the rear end cover (316) of the bearing cavity is located in the empty groove between the rear sealing shell (312) and the rear baffle (315), is locked by screws, and is connected to the integrated shell (308) by bolts.

4. The system for measuring the flow state of lubricating oil in the bearing cavity of an aircraft engine according to claim 3, characterized in that: The simulated low-pressure turbine front shaft (205) in the rotor test piece (101) passes through the simulated high-pressure rear journal (305) in the stator test piece (102), is inserted into the low-pressure turbine front bearing frame (301), and the axial displacement between components is constrained by a spring retaining ring (302).

5. The system for measuring the flow state of lubricating oil in the bearing cavity of an aircraft engine according to claim 3, characterized in that: An oil return pool window (401) is provided on the oil return pool side cover (314) of the stator test piece (102), and a rear end cover window (402) is provided on the rear end cover (316) of the bearing cavity. Cameras are provided outside the oil return pool window (401) and the rear end cover window (402), and the cameras are connected to the controller (601).

6. The system for measuring the flow state of lubricating oil in a bearing cavity of an aircraft engine according to claim 1, characterized in that: The test data acquisition component comprises a lubricating oil leakage amount acquisition unit (701), a bearing cavity pressure acquisition unit (702), a lubricating oil supply amount acquisition unit (703), a lubricating oil recovery amount acquisition unit (704), an air flow acquisition unit (705) and an oil supply flow acquisition unit (706), all of which are connected to the controller (601).

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