Device and method for measuring leakage rate of hydraulic heavy-load seal

Abstract

The invention provides a hydraulic heavy-load sealing leakage rate measuring device and method, and belongs to the technical field of sealing element testing. The device aims at solving the problem that leakage rate measurement is not accurate under the heavy load and high pressure composite working condition. The device comprises a test tool for forming a sealing cavity, a hydraulic system for applying a normal load, a liquid supply system for providing a high-pressure medium, and a measurement module comprising a weighing device. The method comprises the steps of installing a sealing ring, applying a load and supplying a high-pressure medium, then collecting and weighing the mass of the leaked medium by using a weighing device, recording the test duration, and finally calculating the leakage rate according to the mass and the duration. The method can truly simulate harsh working conditions, adopts a mass method for direct measurement, is accurate and reliable in result, and gives consideration to both cost and automation degree.

Description

Technical Field

[0001] This application relates to the field of sealing component testing technology, and in particular to a hydraulic heavy-duty seal leakage rate measurement device and method based on the mass method. Background Technology

[0002] In high-end equipment fields such as aerospace, petrochemicals, and nuclear energy, sealing rings are key components ensuring the safe and stable operation of systems, and the reliability of their sealing performance is paramount. Therefore, accurate leakage performance testing of sealing rings before product application is an essential step.

[0003] Currently, various methods exist for detecting seal leaks. For example, the pressure holding method indirectly estimates the leakage rate by monitoring the rate of pressure drop within the sealing cavity. However, this method is susceptible to fluctuations in ambient temperature and elastic deformation of the cavity, resulting in limited accuracy and time-consuming testing for minute leaks. While helium mass spectrometry leak detection is highly sensitive, its equipment is expensive, operation is complex, and testing costs are high, making it generally unsuitable for routine comparative tests during the R&D phase. Additionally, there are testing devices using the mass method, which determine the leakage rate by collecting the leaking medium and directly measuring its mass. This method provides intuitive and quantitative results. However, existing devices of this type typically only apply medium pressure within the sealing cavity and lack the ability to apply heavy mechanical loads to the sealing ring. For many metal sealing rings operating under heavy loads, a large normal clamping force is a prerequisite for normal operation and a key factor affecting their sealing performance. Therefore, current technologies generally lack a solution for accurately, reliably, and cost-effectively quantitatively measuring the leakage rate of sealing rings under harsh conditions simulating both heavy loads and high internal pressure. Summary of the Invention

[0004] The purpose of this application is to provide a hydraulic heavy-duty seal leakage rate measurement device and method based on the mass method, which aims to solve the problem that existing seal leakage rate detection technology is difficult to accurately, reliably and cost-controllably measure minute leaks under harsh working conditions of heavy load and high internal pressure.

[0005] To achieve the above objectives, this application provides a hydraulic heavy-duty seal leakage rate measuring device, characterized in that it comprises: a test fixture including a base and a pressure member, wherein a sealing cavity for accommodating the seal ring to be tested is formed between the base and the pressure member, the pressure member having an oil injection hole for inputting high-pressure medium, and the base having an oil collection hole for collecting leakage medium; a hydraulic system for applying a normal load to the test fixture; a fluid supply system for supplying high-pressure medium to the sealing cavity via the oil injection hole; and a measuring module including a weighing device for collecting and weighing the leakage medium flowing out from the oil collection hole.

[0006] Optionally, the measurement module further includes a pressure sensor for monitoring the normal load applied by the hydraulic system.

[0007] Optionally, the device further includes a control system electrically connected to the hydraulic system and the fluid supply system for controlling the operation of the hydraulic system and the fluid supply system.

[0008] Optionally, the control system includes a software control interface for receiving target pressure parameters set by the operator, and the control system can automatically control the hydraulic system to load and maintain pressure according to the target pressure parameters.

[0009] Optionally, the control system also has data acquisition and pressure curve display functions, used to record data during the test and visualize the pressure change over time in the form of a curve.

[0010] Optionally, the liquid supply system includes a medium pump, an overflow valve, and a reversing valve, and the reversing valve is used to pressurize, maintain, and depressurize the sealed cavity.

[0011] This application also provides a method for measuring the leakage rate of a hydraulic heavy-duty seal, characterized by the following steps: installing the seal ring to be tested between the base and the pressure member of a test fixture to form a sealing cavity; applying a normal load to the test fixture using a hydraulic system; supplying a high-pressure medium into the sealing cavity using a liquid supply system; collecting and weighing the mass of the medium leaking from the test fixture using a weighing device and recording the test duration; and calculating the leakage rate based on the weighed mass of the medium and the test duration.

[0012] Optionally, the step of applying the normal load may further include: using a pressure sensor to monitor the value of the normal load.

[0013] Optionally, at least one of the steps of applying the normal load and supplying the high-pressure medium is executed automatically by a control system.

[0014] Optionally, the method further includes at least one of using the control system to record data during the test process and to generate and display a curve showing the change of pressure over time.

[0015] Compared with existing technologies, this application has the following advantages: First, the present invention can simultaneously apply heavy loads and high-pressure media, truly replicating the harsh working environment of heavy-duty sealing rings, making the measurement results more valuable for practical engineering reference and more accurate. Second, the present invention adopts a mass method that directly measures the mass of the leaking medium, avoiding measurement errors caused by indirect factors such as temperature and volume changes in the pressure holding method, resulting in intuitive and highly reliable results. Third, compared with the expensive and complex helium mass spectrometry leak detection method, the present invention has a relatively simple equipment structure, lower cost, and convenient operation, making it particularly suitable for batch testing and optimization iteration in the product development stage. Finally, through the integrated control system, precise automated control of the loading and pressure holding processes can be achieved, reducing human error and improving the repeatability and reliability of the test. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A schematic diagram of the overall structure of a hydraulic heavy-duty seal leakage rate measuring device provided in this application embodiment;

[0018] Figure 2 for Figure 1 Schematic diagram of the cross-sectional structure of the pilot test fixture;

[0019] Figure 3 for Figure 1 Schematic diagram of the hydraulic system;

[0020] Figure 4 for Figure 1 A schematic diagram of the liquid supply system.

[0021] [Explanation of Labels in the Attached Image]

[0022] 10-Control system; 20-Hydraulic system; 30-Test fixture; 40-Measurement module; 50-Liquid supply system; 201-Oil tank; 202-Pump station; 203-Hydraulic valve and sensor integrated module; 204-Hydraulic press; 301-Base; 302-Pressure component; 303-Sealing cavity; 304-Sealing ring to be tested; 305-Oil filling hole; 306-Oil collecting hole; 401-Weighing device; 402-Pressure sensor; 501-Oil tank; 502-Pressure gauge; 503-Reversing valve and relief valve integrated module; 504-Media pump. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are intended to explain this application and not to limit it.

[0024] Example 1

[0025] This application provides a hydraulic heavy-duty seal leakage rate measuring device. Please refer to... Figure 1 The figure is a schematic diagram of the overall structure of a hydraulic heavy-duty seal leakage rate measuring device provided in an embodiment of this application. The device is designed to simulate the harsh working conditions of heavy load and high internal pressure acting simultaneously, and to accurately and reliably quantitatively measure the leakage rate of the seal by directly measuring the mass of the leaking medium.

[0026] like Figure 1 As shown, the equipment as a whole may include five main parts that work together: control system 10, hydraulic system 20, test fixture 30, measurement module 40 and liquid supply system 50, which together constitute a complete test system.

[0027] The control system 10, as the control center of the entire equipment, communicates and controls the hydraulic system 20, the fluid supply system 50, and the measurement module 40 via electrical connections. It is configured to receive operator commands, coordinate the actions of the hydraulic system 20 and the fluid supply system 50, and collect and process feedback data from the measurement module 40, thereby achieving automation and precise control of the testing process.

[0028] The hydraulic system 20 is used to provide a large normal load. In many engineering applications, seals require extremely high clamping forces to perform their sealing function, and the hydraulic system 20 simulates this clamping force. Specifically, it acts on the test fixture 30, applying a stable and precisely controllable normal load, which can be up to hundreds of tons, to realistically reproduce the stress state of the seal during actual assembly and operation.

[0029] The fluid supply system 50 is used to provide a high-pressure medium for testing. It is connected to the test fixture 30 via a high-pressure pipeline, delivering the medium into the sealed cavity inside the test fixture 30 and establishing a high-pressure environment. Understandably, this medium pressure is also intended to simulate the internal fluid pressure that the seal needs to withstand under actual operating conditions, such as up to tens of megapascals.

[0030] The test fixture 30, as the core component for sealing testing, provides a controllable testing environment for the seal ring under test. Its structure is specially designed to withstand the enormous normal load from the hydraulic system 20 and the enormous internal pressure from the fluid supply system 50. Once the seal ring under test is installed inside the test fixture 30, a closed sealing cavity is formed.

[0031] The measurement module 40 is configured to quantitatively measure the test results. In one embodiment of this application, the core of the measurement lies in the use of a mass method. When a leak occurs in the seal within the test fixture 30, the leaked medium is guided to the measurement module 40 through a specific channel. The measurement module 40 collects and weighs the leaked medium to obtain the mass of the leak. Accordingly, the measurement module 40 may also include sensors for monitoring key test parameters, such as sensors for monitoring the magnitude of the normal load.

[0032] The following will combine Figure 2 , Figure 3 and Figure 4 This provides a more detailed explanation of each component.

[0033] Please see Figure 2 The figure shows a schematic cross-sectional view of the test fixture 30. Specifically, the test fixture 30 is a key structure for achieving combined heavy-load and high-pressure loading. In this embodiment, the test fixture 30 mainly consists of a base 301 and a pressure member 302. The base 301 and the pressure member 302 are typically made of high-strength alloy steel (such as 42CrMo) and undergo appropriate heat treatment to ensure sufficient strength, rigidity, and dimensional stability when subjected to huge loads and high pressures.

[0034] An annular groove for placing the sealing ring 304 to be tested is machined above the base 301. The lower end face of the pressure member 302 is in contact with the upper surface of the sealing ring 304 to be tested. When the pressure member 302 is pressed down onto the base 301 by the hydraulic system 20, the sealing ring 304 to be tested is compressed, and its inner and outer sides, together with the side walls of the base 301 and the pressure member 302, form an annular, closed sealing cavity 303.

[0035] To inject high-pressure medium into the sealing cavity 303, an oil injection hole 305 is provided at the center of the pressure member 302 or other suitable location. This oil injection hole 305 penetrates the pressure member 302, and its upper end is equipped with a standard high-pressure connector for connecting a high-pressure oil pipe from the fluid supply system 50. The high-pressure medium is then injected into the sealing cavity 303 through this hole.

[0036] To collect any potential leaks, an oil collection hole 306 is provided on the base 301. This oil collection hole 306 is typically positioned below and to the outside of the sealing interface of the sealing ring 304 being tested. When a tiny gap exists at the sealing interface, causing high-pressure media within the sealing cavity 303 to leak outwards, the leaked media will collect in a specific area of ​​the base 301 under gravity and eventually flow out through the oil collection hole 306. It should be noted that the outlet of the oil collection hole 306 can be connected to a drainage pipe to precisely guide the leaked media into the collection container of the weighing device.

[0037] Please see Figure 3 The diagram shows a schematic of the hydraulic system 20. The hydraulic system 20, as a powerful power unit, generates and controls the normal load applied to the test fixture 30. Alternatively, the hydraulic system 20 can be a standard four-column hydraulic press 204, with a maximum loading capacity selectable according to testing requirements, such as 200 tons or higher. The system mainly includes an oil tank 201, a pump station 202, and a hydraulic valve and sensor integrated module 203.

[0038] The oil tank 201 is used to store hydraulic oil and serves to dissipate heat and settle impurities. The pump station 202, as the power core of the system, is typically composed of a motor and a high-pressure oil pump. It is responsible for drawing hydraulic oil from the oil tank 201 and pressurizing it to the working pressure required by the system.

[0039] The hydraulic valve and sensor integration module 203 is the control core of the hydraulic system 20. It integrates various hydraulic valves (including but not limited to solenoid directional valves, proportional relief valves, check valves, etc.) and pressure sensors for monitoring system status. This module receives electrical signals from the control system 10 and precisely regulates the flow rate, direction, and pressure of hydraulic oil flowing into or out of the main cylinder of the hydraulic press 204 by controlling the opening and closing and the degree of opening of the valves. This enables the control of a series of actions such as rapid descent, slow pressurization, precise pressure holding, and rapid return of the movable pressure plate of the hydraulic press 204.

[0040] The hydraulic press 204 is the final actuator. Its movable pressure plate moves downward under the drive of hydraulic oil, directly acting on the pressure member 302 of the test fixture 30, thereby applying the required normal load.

[0041] Please see Figure 4 The figure shows a schematic diagram of the fluid supply system 50. The fluid supply system 50 is an independent, small hydraulic station with a single function: to provide a stable and clean high-pressure test medium to the sealed cavity 303. This system may include a medium tank 501, a medium pump 504, an integrated module 503 that integrates a directional valve and a relief valve, and a pressure gauge 502 for intuitive readings.

[0042] The medium tank 501 is used to store the test medium, which can be hydraulic oil or other liquids selected according to the actual working conditions. The medium pump 504, such as a small gear pump or piston pump, is responsible for pressurizing the medium. The directional valve and relief valve integrated module 503 is used to control the flow direction and pressure of the medium. By operating the directional valve in this module, pressurization, pressure holding, and pressure relief of the sealed cavity 303 can be achieved. The relief valve is used to set and limit the maximum output pressure of the system, playing a role in safety protection and pressure regulation. The pressure gauge 502 displays the medium pressure value output to the test fixture 30 in real time.

[0043] Back Figure 1 In this embodiment, the measurement module 40 includes a weighing device 401 and a pressure sensor 402. The pressure sensor 402, for example a spoke-type or column-type pressure sensor with a range of 300 tons (also referred to as a load sensor), is placed between the worktable of the hydraulic press 204 and the base 301 of the test fixture 30. Its function is to measure the normal load actually applied to the test fixture 30 by the hydraulic system 20 in real time and accurately. The measurement signal is fed back to the control system 10 for closed-loop load control and data recording.

[0044] The weighing device 401, such as an electronic balance with an accuracy of 0.1 grams or higher, is placed below the oil collection port 306 of the test fixture 30. A clean collection container (such as a beaker) is placed on the tray of the weighing device 401, and the leaked medium flowing from the oil collection port 306 is collected in the container. By recording the total mass of the container and the medium at the beginning and end of the test, or by continuously monitoring the change in mass, the total mass of the leaked medium over a certain test period can be accurately obtained.

[0045] By combining the above components, the device in this embodiment can simultaneously apply a precise normal load and a precise internal medium pressure to the test fixture 30 under unified control, and can calculate the leakage rate of the seal ring 304 under the combined working condition by directly weighing the mass of the leaking medium.

[0046] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A hydraulic heavy-duty seal leakage rate measuring device, characterized in that, include: The test fixture includes a base and a pressure member, and a sealing cavity is formed between the base and the pressure member to accommodate the sealing ring to be tested. The pressure member is provided with an oil injection hole for inputting high pressure medium, and the base is provided with an oil collection hole for collecting leaked medium. A hydraulic system is used to apply a normal load to the test fixture; A liquid supply system is used to deliver a high-pressure medium into the sealed cavity via the oil injection hole; and The measurement module includes a weighing device for collecting and weighing the leaked medium flowing out of the oil collection hole.

2. The device according to claim 1, characterized in that, The measurement module also includes a pressure sensor for monitoring the normal load applied by the hydraulic system.

3. The device according to claim 1 or 2, characterized in that, It also includes a control system, which is electrically connected to the hydraulic system and the fluid supply system, and is used to control the operation of the hydraulic system and the fluid supply system.

4. The device according to claim 3, characterized in that, The control system includes a software control interface, which is used to receive target pressure parameters set by the operator, and the control system can automatically control the hydraulic system to load and maintain pressure according to the target pressure parameters.

5. The device according to claim 4, characterized in that, The control system also has data acquisition and pressure curve display functions, which are used to record data during the test and visualize the change of pressure over time in the form of a curve.

6. The device according to claim 1, characterized in that, The liquid supply system includes a medium pump, an overflow valve, and a reversing valve. The reversing valve is used to pressurize, maintain, and depressurize the sealed cavity.

7. A method for measuring the leakage rate of a hydraulic heavy-duty seal, characterized in that, Includes the following steps: The sealing ring to be tested is installed between the base of a test fixture and the pressure component to form a sealing cavity; A hydraulic system is used to apply a normal load to the test fixture; A liquid supply system is used to supply high-pressure medium into the sealed cavity; A weighing device was used to collect and weigh the mass of the medium leaking from the test fixture, and the test duration was recorded. and The leakage rate is calculated based on the measured mass of the medium and the test duration.

8. The method according to claim 7, characterized in that, The step of applying the normal load also includes: using a pressure sensor to monitor the value of the normal load.

9. The method according to claim 7 or 8, characterized in that, At least one of the steps of applying the normal load and supplying the high-pressure medium.

10. The method according to claim 9, characterized in that, Also includes: The control system is used to record data during the test and to generate and display at least one of the following: pressure changes over time.

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