Hydraulic system sealing test bench and sealing performance test method

Abstract

The invention discloses a hydraulic system sealing test bench and a sealing performance test method, and belongs to the technical field of sealing performance detection, the test bench comprises a vibration device, a pressure control system, a sealing element installation device, a flow adjusting system and a micro leakage detection unit; a to-be-tested sealing element is installed in the sealing element installation device to form a sealing cavity, and the sealing cavity is communicated with the pressure control system, the flow adjusting system and the hydraulic oil tank through pipelines to form a closed hydraulic loop. The vibration device is arranged on the outer side of the sealing element mounting device and used for applying vibration loads, the pressure control system is used for providing and adjusting hydraulic pressure in the sealing cavity, the flow adjusting system is used for controlling the flowing speed and flow of a hydraulic medium, and the micro-leakage detection unit is arranged below the sealing element mounting device and used for detecting leakage of the sealing cavity. The method has the advantages of being high in test condition controllability, high in leakage detection sensitivity, wide in adaptability and high in test result engineering guidance.

Description

Technical Field

[0001] This invention belongs to the field of sealing performance testing technology, and specifically relates to a hydraulic system sealing test bench and sealing performance testing method. Background Technology

[0002] Hydraulic systems are widely used in critical equipment such as governors of hydropower units. Various seals (such as O-rings and gaskets) ensure that hydraulic oil does not leak in high-pressure pipelines and actuators. The reliability of these seals directly affects the normal operation of the hydraulic system and equipment safety: if a seal fails and hydraulic oil leaks, it will not only cause a drop in system pressure, affecting the governor's control accuracy, but may also lead to environmental pollution and safety hazards. Therefore, it is necessary to conduct rigorous performance testing and durability assessments of the seals in hydraulic systems.

[0003] Existing hydraulic seal performance testing methods have several shortcomings. For example, sealing tests are typically conducted only under static or single conditions (such as observing leaks at constant pressure and temperature), failing to adequately consider dynamic factors such as pressure pulsations, fluid flow impacts, and equipment vibrations in actual operating conditions. Furthermore, the detection of minute leaks often relies on long-term pressure decay methods or manual visual inspection, which has limited accuracy and real-time performance. These limitations mean that test results cannot fully reflect the performance of seals in real-world working environments, making it difficult to accurately assess the lifespan and reliability of seals.

[0004] Especially in the hydraulic system of hydropower unit speed governor, the vibration and oil temperature changes generated during equipment operation may accelerate the aging and leakage of O-rings and other seals. However, traditional test equipment lacks the ability to assess sealing performance under vibration conditions, and the test conditions differ from the actual situation. Therefore, the test data is not effective enough for engineering guidance.

[0005] In summary, there is an urgent need for a hydraulic seal testing platform that can simulate real-world working conditions, including pressure, flow rate, temperature, and vibration factors, in order to accurately measure micro-leakage of the seal and evaluate its sealing performance under complex conditions. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a hydraulic system sealing test bench and a sealing performance testing method. This test bench can simulate the actual working conditions of a hydroelectric generator governor's hydraulic system, conducting sealing failure experiments and sealing performance tests under vibration conditions. It offers advantages such as high adjustability, integrated vibration testing, and precise measurement of micro-leakage.

[0007] The present invention adopts the following technical solution.

[0008] The first aspect of the present invention discloses a hydraulic system sealing test bench, the test bench comprising: a vibration device, a pressure control system, a seal installation device, a flow regulation system, a micro-leakage detection unit, and a data acquisition and analysis module; The seal to be tested is installed in the seal installation device to form a sealed cavity. The sealed cavity is connected to the pressure control system, the flow regulation system and the hydraulic oil tank through pipelines to form a closed hydraulic circuit. The vibration device is located outside the sealing installation device and is used to apply vibration load to the sealing installation device. The pressure control system is used to provide and regulate the hydraulic pressure in the sealing cavity. The flow regulation system is used to control the flow rate and flow of the hydraulic medium. The micro-leakage detection unit is located below the sealing installation device and is used to detect leakage in the sealing cavity. The data acquisition and analysis module is used to acquire and analyze pressure, temperature, vibration, flow and leakage data during the test.

[0009] Preferably, the sealing element installation device includes: a flange connection assembly, which clamps and fixes the sealing element by two flange connection assemblies, and a sealing cavity filled with hydraulic medium is formed in the middle of the flange connection assembly.

[0010] Preferably, the pressure control system includes a hydraulic pump and an accumulator, wherein the hydraulic pump is used to drive the flow of hydraulic medium, and the accumulator is used to store and release energy to help the hydraulic pump maintain the pressure within the system.

[0011] Preferably, the flow regulation system includes a hydraulic valve for controlling the circulation flow rate and velocity of the hydraulic medium in the pipeline. By adjusting the opening degree of the hydraulic valve, the opening degree of the hydraulic oil tank can be controlled, allowing it to switch between multiple modes.

[0012] Preferably, the multiple modes include: static pressure holding mode and circulating flow mode; The static pressure holding mode involves closing the hydraulic valve and increasing the pressure of the sealing cavity without any medium flow, and is used for static sealing tests. The circulating flow mode involves opening the hydraulic valve, allowing the medium to circulate within the sealed cavity at a preset flow rate, thereby generating a continuous liquid flow to flush the seal.

[0013] Preferably, the micro-leakage detection device is connected to the sealing installation device via a pipe, and a leakage collection port is provided at the bottom of the connection between the flange connection assembly and the sealing element. The leakage collection port is led out to the micro-leakage detection unit via a pipe.

[0014] Preferably, the microleakage detection unit includes: an electronic flow meter and a pressure sensor; The electronic flow meter is used to monitor the leakage at the leak collection port and output the signal to the data acquisition and analysis module; the pressure sensor is used to monitor the change in cavity pressure caused by the leakage and output the signal to the data acquisition and analysis module.

[0015] Preferably, the vibration device is connected to the seal mounting device and can apply vibration loads along the axial and / or radial direction of the seal to simulate the vibration conditions during equipment operation.

[0016] A second aspect of the present invention discloses a method for testing sealing performance based on the hydraulic system sealing test bench described in the first aspect, comprising the following steps: The seal to be tested is installed in the seal mounting device to form a sealed cavity; Start the pressure control system to raise the pressure in the sealed cavity to the target value, and set the pressure holding time or periodic fluctuation characteristics according to the test requirements; The flow regulation system is activated to drive the hydraulic medium to circulate in the sealed cavity circuit according to the preset flow rate, so as to simulate the effect of fluid flow on the seal under actual working conditions. After the steady-state pressure is reached, the vibration device is activated to apply a mechanical vibration load of a set frequency and amplitude to the seal and maintain it for a predetermined time. During the test, the leakage of the seal under vibration and pressure was monitored by a micro-leakage detection unit; The data acquisition and analysis module synchronously collects temperature, pressure, flow rate, vibration, and leakage data during the test. After the test is completed, the data is analyzed and processed to evaluate the sealing performance and durability of the seal.

[0017] Preferably, during the test, when the detected leakage exceeds a predetermined threshold, an alarm is triggered and the test is stopped, and the pressure control system and vibration device are shut down to protect the equipment.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: The test bench described in this invention can accurately simulate the combined conditions of pressure, flow rate, temperature and mechanical vibration under real working conditions in the laboratory, and conduct comprehensive performance tests on the sealing components. The test bench of this invention integrates a highly sensitive micro-leakage detection unit, which can capture extremely small leakage changes in real time, improve test accuracy, and all parameters are centrally controlled and recorded by the data acquisition and analysis module, realizing the automation and standardization of the test, reducing human error. The test bench has a compact and modular structure design, which can be adapted to sealing samples of different sizes and types, and has wide applicability. Attached Figure Description

[0019] Figure 1This is a schematic diagram of the hydraulic system sealing test bench of the present invention; Figure 2 This is a flowchart of the sealing performance testing method of the present invention; Figure 3 This is a schematic diagram of the sealing element installation device of the present invention; In the diagram: 1. Vibration device; 2. Seal installation device; 3. Flange connection assembly; 4. Pressure control system; 5. Flow regulation system; 6. Micro-leakage detection unit; 7. Seal; 8. Leakage collection port; 9. Hydraulic oil tank. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this invention. The embodiments described in this application are merely some embodiments of this invention, and not all embodiments. Based on the spirit of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this invention.

[0021] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention.

[0022] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0023] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0024] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0025] like Figure 1 , 3 As shown, Embodiment 1 of the present invention provides a hydraulic system sealing test bench, including: a vibration device 1, a seal installation device 2, a pressure control system 4, a flow regulation system 5, a micro-leakage detection unit 6, and a hydraulic oil tank 9, which are installed on the same frame structure to form a complete test circuit.

[0026] Specifically, the seal to be tested 7 is installed in the seal installation device 2. The seal installation device 2 is designed as a sealing cavity structure similar to the actual equipment, including a flange connection assembly 3. The seal 7 is clamped and fixed by two flange connection assemblies 3, and a sealing cavity filled with hydraulic medium is formed in the middle of the flange connection assembly 3.

[0027] The sealed cavity is connected to the pressure control system 4, the flow regulation system 5, and the hydraulic oil tank 9 via pipelines, forming a closed hydraulic circuit. It is worth noting that the sealed cavity refers to the entire closed hydraulic circuit of the equipment; the portion where the flange connection assembly 3 and the seal 7 mate is also connected to the pipelines.

[0028] The pressure control system 4 includes a hydraulic pump and an accumulator, the outlet of which is connected to a sealed cavity via a pipeline, providing variable hydraulic pressure to the sealed cavity. The hydraulic pump is used to drive the flow of oil, and the accumulator is used to store and release energy to help the hydraulic pump maintain the pressure within the system, which helps to regulate pressure fluctuations and ensures stable operation of the system during testing.

[0029] The flow regulation system 5 includes an adjustable hydraulic valve for controlling the circulation flow rate and velocity of hydraulic oil in the pipeline. When the valve is fully closed, a pressure holding test can be performed within the cavity; when the valve is partially open, the hydraulic oil circulates within the system, simulating the flow of fluid through the seals during actual operation.

[0030] Specifically, the flow regulation system 5 includes an adjustable hydraulic valve connected in series between the sealed cavity and the pressure control system 4.

[0031] By adjusting the opening of the hydraulic valve, the opening of the hydraulic oil tank 9 can be controlled, allowing it to switch between two modes: one is the static pressure holding mode, where the hydraulic valve is closed, thus completely shutting off the circulation loop, only increasing the pressure of the sealing cavity without oil flow, used for static sealing tests. The second mode is the circulating flow mode, which involves partially opening the hydraulic valves to allow the hydraulic oil in the hydraulic oil tank 9 to circulate within the system. In circulating mode, the hydraulic pump drives the oil to flow in the circuit at a preset flow rate, for example, a flow rate of 10 L / min through the sealed cavity. This creates a continuous fluid scouring effect at the seals.

[0032] This invention achieves the simulation of fluid flow effects under actual operating conditions in experiments through this structure: for static seal testing, the flow rate can be set to 0 to verify the sealing performance under pure hydrostatic pressure; while in dynamic operating condition simulation, a circulating fluid flow at a certain velocity is introduced, subjecting the seal to fluid impact and disturbance similar to that in a real hydraulic system. The introduction of the flow regulation system 5 allows the test bench to examine the scouring and thermal effects of fluid flow on the seal. For example, rapidly flowing oil may weaken the oil film around the seal or carry away heat; this device can reproduce this effect and evaluate its impact on leakage.

[0033] The vibration device 1 is installed on the outside of the sealing element mounting device 2 and is connected to the flange connection assembly 3 through a rigid connector. It can apply a mechanical vibration load with adjustable frequency and amplitude to the sealing element 7.

[0034] In a preferred but non-limiting embodiment of the present invention, the vibration device 1 uses an electromagnetic vibration table or a hydraulic servo actuator as the vibration source, and is connected to the upper flange connection assembly 3 of the sealing element mounting device 2 via a rigid connector, thereby enabling the application of vibration loads along the axial and / or radial direction of the sealing element. This rigid connection design ensures that vibration can be effectively transmitted to the sealing element 7 itself. The vibration parameters are preset by the control system, and the frequency and amplitude can be adjusted within a wide range (e.g., frequency adjustable from 10 to 100 Hz, amplitude set to the desired value).

[0035] In a specific embodiment, an electromagnetic vibration table applies periodic vibration perpendicular to the flange surface to the flange connection assembly 3. The vibration frequency can be set to 50Hz and the vibration acceleration to 5g, and the vibration can be applied continuously for several hours to simulate the mechanical vibration effect on the seals during the operation of a water turbine. At the same time, an acceleration sensor installed near the flange monitors the vibration acceleration signal in real time and transmits the feedback to the data acquisition and analysis module to ensure that the actual output vibration amplitude is consistent with the set value.

[0036] Through the above improvements, the vibration loading device of the present invention can accurately control vibration conditions, realize the simulation of equipment operation vibration conditions, make the test closer to the real working conditions, and evaluate the influence of vibration on sealing performance.

[0037] The micro-leakage detection device 6 is connected to the sealing component installation device 2 via a pipe and is used to detect whether the sealing component 7 under test has micro-leakage. In a preferred but non-limiting embodiment of the present invention, a leakage collection port 8 is provided at the bottom of the connection between the flange connection assembly 3 and the seal 7, which is led out through a thin pipe and connected to the micro-leakage detection unit 6.

[0038] The micro-leakage detection unit 6 includes a high-precision electronic flow meter and a pressure sensor. When a very small leak occurs in the seal 7, droplets will enter the flow meter through the collection port 8, and the minute change in flow rate can be sensed and converted into an electrical signal output. Simultaneously, the pressure sensor inside the sealed cavity can detect the minute decrease in cavity pressure over time due to the leak. The data acquisition and analysis module fuses the information from both, and calculates the instantaneous leakage rate using software algorithms, achieving quantitative analysis.

[0039] For example, the system can display in real time that a leakage rate of 0 indicates a good seal, while if the leakage rate is found to gradually rise to a small value such as 0.1 mL / min, it is determined that the sealing performance has begun to deteriorate. The micro-leakage detection unit 6 significantly improves the sensitivity and accuracy of leakage detection: it can detect early signs of leakage in the seal and quantify the leakage rate, providing a reliable basis for evaluating seal life and failure modes.

[0040] In addition, the micro-leakage detection unit 6 is equipped with a safety interlock strategy—once the leakage exceeds a preset threshold (such as 5 mL / min), the system will automatically alarm and shut down the pressure source and vibration source to prevent a large amount of oil from spraying out and damaging the equipment, thus ensuring the safety of the test.

[0041] The data acquisition and analysis module amplifies and records the signal from the micro-leakage detection unit 6, and calculates the instantaneous leakage rate using software algorithms. To capture very low leakage amounts, the sealed cavity is initially filled with degassed hydraulic oil to ensure that the sensitivity of leak detection is not affected by air bubbles.

[0042] The entire test bench is coordinated and controlled by a programmable logic controller (PLC) or industrial computer. All sensors and actuators (such as motors, valves, vibrators, etc.) are connected to the data acquisition and analysis module, which executes the preset test process and records the data.

[0043] like Figure 2 As shown, Embodiment 2 of the present invention provides a sealing performance testing method, based on a hydraulic system sealing test bench described in Embodiment 1, comprising the following steps: Sample installation: Select the seal to be tested 7 (e.g., an O-ring of suitable diameter), check that it is intact, and install it in the sealing groove of the seal installation device 2. Close the two flange connection assemblies 3 and tighten the flange connection assemblies 3 with bolts to form a sealing cavity. Ensure that the flange connection assemblies 3 are tightly connected and the seal is evenly pressurized, thereby avoiding leakage caused by uneven initial installation stress.

[0044] Medium injection: Open the valve of hydraulic oil tank 9 on the test bench, start the hydraulic pump to inject hydraulic oil into the sealed cavity until it is full and the air in the cavity is expelled.

[0045] Pressure loading: Start the hydraulic pump of pressure control system 4 and gradually close the hydraulic valve in the circuit to slowly increase the pressure in the sealed cavity to the target pressure value (e.g., 6.3MPa, simulating the normal operating pressure of the speed governor). It is worth noting that if the test requires examining the pressure resistance limit of seal 7, the pressure can be increased to a higher value, but must not exceed the upper limit of the test bench design. Stabilize the pressure for a period of time to check for leakage of the seal under static high pressure. If it is necessary to simulate pressure fluctuations, the pressure control system 4 can be pre-programmed to generate periodic pressure changes (e.g., sinusoidal fluctuations in the range of 4~6MPa) to evaluate the sealing stability of the seal under pressure shocks.

[0046] Flow regulation: According to the test plan requirements, adjust the opening of the control valve in the flow regulation system 5 to set the circulating flow rate of hydraulic oil in the system circuit. For static sealing tests, the flow rate can be set to zero (i.e., the circulation loop is closed, only the pressure is maintained); for dynamic operating condition simulation, a certain flow rate can be set to allow the hydraulic oil to circulate (e.g., 10 L / min), thereby generating a fluid scouring effect at the seal. This step is used to simulate the possible effects of oil flow on the seal in the governor hydraulic system (such as hydrodynamic action, temperature rise effect, etc.).

[0047] Vibration loading: After the temperature, pressure and flow rate have all reached the set steady state, start the vibration device 1.

[0048] In this embodiment, the vibration device applies axial periodic vibration. According to the test requirements, the vibration frequency is set to 50Hz, the amplitude to 0.5mm, and the vibration duration to 2 hours. During the vibration, an accelerometer continuously monitors the vibration acceleration signal at the flange connection assembly 3 to ensure that the actual vibration amplitude meets the set value. By superimposing the vibration load, the dynamic disturbance effect of the hydropower unit on the seal 7 during operation can be simulated, making the test closer to real working conditions. If it is necessary to study the effect of different vibration intensities on sealing performance, the frequency (e.g., within the range of 10–100Hz) and amplitude of the vibration device can be adjusted, and comparative tests can be conducted separately.

[0049] Micro-leakage monitoring: When pressure and vibration act simultaneously on the seal, slight signs of leakage may appear. At this point, the micro-leakage detection unit 6 comes into play: on one hand, the pressure sensor inside the sealed cavity samples the cavity pressure data at high frequency, transmitting it to the data acquisition and analysis module, which plots it as a pressure-time curve and monitors for a slow downward trend; on the other hand, the flow meter detects whether there is an oil flow signal in the leakage channel. Once even a tiny amount of oil leaks through the seal and flows out along the leak outlet, the flow meter outputs a weak pulse signal, which is amplified and recorded by the data acquisition module. The testing personnel can view the leakage reading in real time on the monitoring interface.

[0050] For example, if the leakage rate remains at 0, it indicates that the seal is intact; if the leakage rate gradually increases to values ​​such as 0.1 mL / min, it indicates that the sealing performance has begun to deteriorate.

[0051] For safety reasons, the system has an automatic protection logic in this step: if the detected leakage exceeds a preset threshold (e.g., 5 mL / min), the data acquisition module will trigger an alarm and interlock to shut down the pressure control system and vibration device to prevent a large amount of oil from spraying out and damaging the equipment.

[0052] Data Acquisition and Analysis: Throughout the experiment, the data acquisition and analysis module synchronously records data from each sensor, including: real-time pressure value inside the sealed cavity, hydraulic oil temperature, circulation flow rate, vibration frequency and amplitude, and cumulative leakage.

[0053] After the test was completed, the data were exported and used to analyze the sealing performance indicators.

[0054] For example, the stability of a seal can be determined by analyzing the pressure-time curve, and the leakage rate change of the seal at different stages can be calculated by the leakage-time curve. Combining vibration acceleration data can study the influence of vibration on leakage. If a seal life test is being conducted, the time point of seal failure and the failure mode (e.g., sudden increase in leakage due to fatigue cracking) can be determined based on the leakage rate increasing over test time. The data analysis module provided by the test bench of this invention can also automatically generate test reports, providing evaluation results on the pressure resistance limit, vibration resistance, and durability of the seal, providing a scientific basis for improving seal design and material selection.

[0055] The beneficial effects of this invention are that, compared with the prior art, The test bench described in this invention can accurately simulate the combined conditions of pressure, flow rate, temperature and mechanical vibration under real working conditions in the laboratory, and conduct comprehensive performance tests on the sealing components. The test bench of this invention integrates a highly sensitive micro-leakage detection unit, which can capture extremely small leakage changes in real time, improve test accuracy, and all parameters are centrally controlled and recorded by the data acquisition and analysis module, realizing the automation and standardization of the test, reducing human error. The test bench has a compact and modular structure design, which can be adapted to sealing samples of different sizes and types, and has wide applicability.

[0056] This disclosure can be a system, method, and / or computer program product. A computer program product may include a computer-readable storage medium having computer-readable program instructions loaded thereon for causing a processor to implement various aspects of this disclosure.

[0057] Computer-readable storage media can be tangible devices capable of holding and storing instructions for use by an instruction execution device. Computer-readable storage media can be, for example—but not limited to—electrical storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of computer-readable storage media include: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), portable compact disc read-only memory (CD-ROM), digital multifunction disc (DVD), memory sticks, floppy disks, mechanical encoding devices, such as punch cards or recessed protrusions storing instructions thereon, and any suitable combination of the foregoing. The computer-readable storage media used herein are not to be construed as transient signals themselves, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides or other transmission media (e.g., light pulses through fiber optic cables), or electrical signals transmitted through wires.

[0058] The computer-readable program instructions described herein can be downloaded from computer-readable storage media to various computing / processing devices, or downloaded via a network, such as the Internet, local area network, wide area network, and / or wireless network, to an external computer or external storage device. The network may include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards them to the computer-readable storage media in the respective computing / processing device.

[0059] Computer program instructions used to perform the operations of this disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, status setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, etc., and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The computer-readable program instructions may execute entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or may be connected to an external computer (e.g., via the Internet using an Internet service provider). In some embodiments, electronic circuitry, such as programmable logic circuitry, field-programmable gate arrays (FPGAs), or programmable logic arrays (PLAs), is personalized by utilizing the status information of the computer-readable program instructions to implement various aspects of this disclosure.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.

Claims

1. A hydraulic system sealing test bench, characterized in that, The test bench includes: a vibration device (1), a pressure control system (4), a sealing component installation device (2), a flow regulation system (5), a micro-leakage detection unit (6), and a data acquisition and analysis module; The seal to be tested (7) is installed in the seal installation device (2) to form a sealed cavity. The sealed cavity is connected to the pressure control system (4), the flow regulation system (5) and the hydraulic oil tank (9) through pipelines to form a closed hydraulic circuit. The vibration device (1) is located outside the sealing installation device (2) and is used to apply vibration load to the sealing installation device (2). The pressure control system (4) is used to provide and adjust the hydraulic pressure in the sealing cavity. The flow regulation system (5) is used to control the flow rate and flow of the hydraulic medium. The micro-leakage detection unit (6) is located below the sealing installation device (2) and is used to detect leakage in the sealing cavity. The data acquisition and analysis module is used to collect and analyze the pressure, temperature, vibration, flow and leakage data during the test.

2. The hydraulic system sealing test bench according to claim 1, characterized in that, The sealing installation device (2) includes: a flange connection assembly (3), which clamps and fixes the sealing element (7) by means of two flange connection assemblies (3), and a sealing cavity filled with hydraulic medium is formed in the middle of the flange connection assembly (3).

3. The hydraulic system sealing test bench according to claim 1, characterized in that, The pressure control system (4) includes a hydraulic pump and an accumulator, wherein the hydraulic pump is used to drive the flow of hydraulic medium and the accumulator is used to store and release energy to help the hydraulic pump maintain the pressure in the system.

4. The hydraulic system sealing test bench according to claim 1, characterized in that, The flow regulation system (5) includes a hydraulic valve for controlling the circulation flow rate and velocity of the hydraulic medium in the pipeline. By adjusting the opening of the hydraulic valve, the opening of the hydraulic oil tank (9) can be controlled, allowing it to switch between multiple modes.

5. The hydraulic system sealing test bench according to claim 4, characterized in that, The various modes include: static pressure holding mode and circulating flow mode; The static pressure holding mode involves closing the hydraulic valve and increasing the pressure of the sealing cavity without any medium flow, and is used for static sealing tests. The circulating flow mode is to open the hydraulic valve and the medium circulates in the sealed cavity at a preset flow rate to generate a continuous liquid flow scouring at the seal (7).

6. The hydraulic system sealing test bench according to claim 1, characterized in that, The micro-leakage detection device (6) is connected to the sealing installation device (2) through a pipe. A leakage collection port (8) is provided at the bottom of the connection between the flange connection assembly (3) and the sealing element (7). The leakage collection port (8) is led out to the micro-leakage detection unit (6) through a pipe.

7. The hydraulic system sealing test bench according to claim 1, characterized in that, The microleakage detection unit (6) includes: an electronic flow meter and a pressure sensor; The electronic flow meter is used to monitor the leakage at the leak collection port (8) and output the signal to the data acquisition and analysis module; the pressure sensor is used to monitor the change in cavity pressure caused by the leakage and output the signal to the data acquisition and analysis module.

8. The hydraulic system sealing test bench according to claim 1, characterized in that, The vibration device (1) is connected to the sealing installation device (2) and can apply vibration loads along the axial and / or radial direction of the sealing element (7) to simulate the vibration conditions during equipment operation.

9. A method for testing the sealing performance of a hydraulic system based on a sealing test bench according to any one of claims 1-8, characterized in that, Includes the following steps: The seal to be tested (7) is installed in the seal mounting device (2) to form a sealed cavity; Start the pressure control system (4) to raise the pressure in the sealed cavity to the target value, and set the pressure holding time or periodic fluctuation characteristics according to the test requirements; Start the flow regulation system (5) and drive the hydraulic medium to circulate in the sealed cavity circuit according to the preset flow rate to simulate the effect of the liquid flow on the seal (7) under actual working conditions; After reaching steady-state pressure, the vibration device (1) is activated to apply a mechanical vibration load of a set frequency and amplitude to the seal (7) and maintain it for a predetermined time. During the test, the leakage of the seal under vibration and pressure was monitored by the micro-leakage detection unit (6); Temperature, pressure, flow rate, vibration and leakage data are collected synchronously by the data acquisition and analysis module during the test. After the test is completed, the data is analyzed and processed to evaluate the sealing performance and durability of the seal (7).

10. The sealing performance testing method according to claim 9, characterized in that, During the test, when the leakage exceeds the predetermined threshold, an alarm is triggered and the test is stopped. The pressure control system (4) and vibration device (1) are shut down to protect the equipment.

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