Reciprocating sealing reliability test device and method in multi-stress environment

Abstract

The invention provides a reciprocating sealing reliability test device and method in a multi-stress environment, and relates to the technical field of reciprocating sealing reliability test of hydraulic cylinders for ships and warships, and the device comprises a hydraulic cylinder, a load hydraulic system, a stress loading system, a clamp assembly and a detection system. The load hydraulic system is used for supplying oil to the hydraulic cylinder and adjusting the pressure and temperature of the oil. The stress loading system comprises a speed loading module and a vibration loading module. The clamp assembly is used for fixing the hydraulic cylinder, and the first-order inherent frequency is larger than 60 Hz. The detection system is used for collecting and monitoring sealing performance parameters of the hydraulic cylinder in the test process in real time. Three-stress coupling loading of speed, vibration and load is achieved, the service environment of the ship hydraulic cylinder can be simulated and reproduced, the test stability is ensured through the optimal design of the clamp assembly, and the test efficiency is improved through the configuration of the double hydraulic cylinders.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of reliability test of reciprocating seal of hydraulic cylinder for warships, and particularly relates to a reciprocating seal reliability test device and method under multi-stress environment. BACKGROUND

[0002] The hydraulic cylinder of a warship is subjected to the coupling of multiple stresses such as high-pressure oil, reciprocating motion friction, continuous vibration and load fluctuation generated by the sailing of the warship, and the working condition environment is extremely complex. Under this complex stress state, the performance degradation of the reciprocating seal presents nonlinear characteristics, and the failure mechanism is difficult to predict. The existing test device in China has significant deficiencies in simulating the real service environment of the hydraulic cylinder of a warship, mainly in the following aspects: Firstly, the existing test device is mostly based on simplified or idealized experimental conditions, and cannot fully reproduce the multi-stress coupling environment faced by the hydraulic cylinder in actual service. Most devices can only simulate single or partial working condition parameters such as pressure, temperature, and reciprocating speed, and lack consideration of the coupling effect of vibration stress and other stresses, resulting in a large deviation between the test results and the actual service conditions, which seriously restricts the in-depth study of the performance degradation mechanism of the reciprocating seal and the improvement of the accuracy of the life prediction model.

[0003] Secondly, the performance change of the reciprocating seal under complex working conditions often has micro, transient and nonlinear characteristics, such as small fluctuations in friction, gradual changes in seal wear, and phased growth in leakage rate. These subtle changes put high requirements on the measurement accuracy, data sampling frequency and signal processing capability of the test device. However, the existing test device has deficiencies in sensor accuracy and real-time data processing algorithms, making it difficult to achieve high-sensitivity monitoring and accurate analysis of the performance degradation process of the seal, limiting accurate judgment of the failure mechanism of the reciprocating seal.

[0004] Furthermore, the low test efficiency is also a prominent problem of the existing device. The traditional test method usually adopts a single sample test one by one, which has a long test period and cannot meet the needs of batch verification and rapid evaluation, restricting the progress of seal reliability research and product development.

[0005] Chinese patent document CN105673621B discloses an aviation actuator reciprocating seal multi-working condition comprehensive simulation test system, which discloses a technical scheme for simulating high pressure, wide temperature, variable speed and airborne vibration working conditions through a vibration platform, a high-low temperature environment box and a hydraulic system, achieving the technical effects of multi-working condition comprehensive simulation and vibration isolation. However, this scheme is designed for aviation actuators and focuses on vibration isolation rather than multi-stress coupling loading, and adopts a single sample test method, which has low test efficiency and cannot meet the accurate simulation needs of the hydraulic cylinder of a warship under the multi-stress coupling extreme working conditions of high pressure, vibration and load fluctuation.

[0006] Chinese patent document CN109357960B discloses a service fatigue performance test method and test device for a hydraulic reciprocating seal, discloses a technical solution for monitoring contact stress by using a fiber grating strain sensor and judging fatigue state by failure probability calculation, and realizes technical effects of seal fatigue life test and failure state judgment, but the scheme does not involve vibration stress simulation, can only simulate part of working condition parameters such as reciprocating speed, load and temperature, and can not comprehensively reflect the complex performance degradation process of the reciprocating seal of the ship hydraulic cylinder under the multi-stress coupling environment by monitoring a single contact stress parameter. SUMMARY

[0007] The purpose of the present application is to provide a reciprocating seal reliability test device and method under a multi-stress environment, which has a multi-stress coupling loading capability, realizes accurate simulation of complex working conditions of a hydraulic cylinder in actual service under a ship environment, improves data acquisition and analysis capability, and improves test efficiency.

[0008] To achieve the above-mentioned purpose, the present application realizes the following technical scheme: A reciprocating seal reliability test device under a multi-stress environment, comprising: A hydraulic cylinder comprising a cylinder barrel and a piston rod connected in sequence, and a seal provided in the cylinder barrel; A load hydraulic system for supplying oil to the hydraulic cylinder and adjusting the pressure and temperature of the oil, the load hydraulic system applying load stress to the hydraulic cylinder through pressure adjustment; A stress loading system comprising a speed loading module and a vibration loading module, the speed loading module being used to drive the piston rod to reciprocate, and the vibration loading module being used to apply vibration stress to the seal; A fixture assembly for fixing the hydraulic cylinder, the first-order natural frequency of the fixture assembly being greater than 60Hz; A detection system for real-time acquisition and monitoring of seal performance parameters of the hydraulic cylinder during the test process; The hydraulic cylinder is installed on the fixture assembly, the stress loading system is connected with the hydraulic cylinder and the fixture assembly respectively, and the detection system is connected with the hydraulic cylinder.

[0009] Further, the hydraulic cylinder comprises a first hydraulic cylinder and a second hydraulic cylinder, the piston rod end of the first hydraulic cylinder is connected with the piston rod end of the second hydraulic cylinder through a tension-compression force sensor, a threaded rod and a flange nut in sequence, and the non-piston rod end of the first hydraulic cylinder and the non-piston rod end of the second hydraulic cylinder are fixed at two ends of the fixture assembly respectively.

[0010] Further, the speed loading module comprises a servo motor, a frequency converter and a speed regulating device, the servo motor is connected with the hydraulic cylinder through the frequency converter and the speed regulating device.

[0011] Further, the vibration loading module comprises a vibration table, and the clamp assembly is fixed on the vibration table.

[0012] Further, the vibration table generates vibration with a frequency range of 16-60 Hz.

[0013] Further, the load hydraulic system comprises an oil tank, an oil pump, a filter, a heater, a cooling fan and an electro-hydraulic servo valve; the heater and the cooling fan are connected with the oil tank, the oil tank is connected with the inlet of the oil pump through the filter, and the outlet of the oil pump is connected with the cylinder barrel of the hydraulic cylinder through the electro-hydraulic servo valve.

[0014] Further, the detection system comprises sensors and a data acquisition and analysis unit connected with each other, and the sensors are installed on the hydraulic cylinder.

[0015] Further, the sensors comprise vibration sensors, oil temperature sensors and tension and pressure sensors; the vibration sensors are installed on the vibration loading module, the clamp assembly and the hydraulic cylinder; the oil temperature sensors are installed on the oil pipeline of the load hydraulic system; and the tension and pressure sensors are installed between the piston rod ends of the first and second hydraulic cylinders and play a connecting role.

[0016] Further, the clamp assembly comprises a first fixed plate, a second fixed plate and a plurality of load connecting structure rods, the first fixed plate and the second fixed plate are fixedly connected through the load connecting structure rods, the first fixed plate is provided with a fixed ear support, and the second fixed plate is provided with a fixed structure.

[0017] A reciprocating sealing reliability test method applied to the above device, comprising the following steps: S1: installing the hydraulic cylinder to be tested in the clamp assembly; S2: adjusting the pressure and temperature of the oil to the preset value through the load hydraulic system; S3: applying acceleration stress and vibration stress to the hydraulic cylinder through the stress loading system, and applying load stress to the hydraulic cylinder through the load hydraulic system; S4: collecting sealing performance parameters of the hydraulic cylinder in real time through the detection system; S5: evaluating the performance degradation state and reliability of the reciprocating sealing element according to the collected sealing performance parameters.

[0018] Compared with the prior art, the present application has the following beneficial effects: Firstly, the present application can accurately simulate the synergistic effect of multiple stresses such as high-pressure oil, reciprocating motion, vibration load and load fluctuation that the ship hydraulic cylinder bears in actual service by constructing a three-stress coupling loading capability including a speed loading module, a vibration loading module and a load hydraulic system, thereby breaking through the limitation of the existing device that can only simulate single or partial working condition parameters, making the test results truly reflect the actual service performance of the reciprocating seal for ships, and providing reliable data support for performance degradation mechanism research and life prediction.

[0019] Secondly, the present application adopts an upper and lower butt joint configuration of two hydraulic cylinders to realize double-sample parallel test, which greatly shortens the test cycle and significantly improves the test efficiency compared with the traditional single-sample test method, thereby speeding up the reliability verification and product development process of the seal; the detection system can comprehensively monitor the performance degradation process of the seal in the multiple stress coupling environment by real-time collection and calculation of various sealing performance parameters such as leakage, friction, temperature and pressure through various sensors, thereby providing rich data support for seal life prediction and reliability evaluation, and more accurately reflecting the actual working state and performance change trend of the seal.

[0020] Thirdly, the present application optimizes the design to make the first-order natural frequency of the clamp assembly reach 74Hz and the strength meet the requirements of the ship environment conditions, thereby ensuring the stability of the device when simulating the ship vibration environment, reducing the error of the test results caused by the characteristics of the clamp itself, and further improving the credibility of the test. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 A structure schematic view of a load pressurizing system of a reciprocating seal reliability test device under a multiple stress environment provided by the present application is shown in the figure. Figure 2 A combination structure schematic view of a clamp assembly, a hydraulic cylinder and a vibration table in a reciprocating seal reliability test device under a multiple stress environment provided by the present application is shown in the figure. Figure 3 A structure schematic view of a clamp assembly in a reciprocating seal reliability test device under a multiple stress environment provided by the present application is shown in the figure. Figure 4 A connection structure schematic view of a hydraulic cylinder in a reciprocating seal reliability test device under a multiple stress environment provided by the present application is shown in the figure. Figure 5 A flowchart of a reciprocating seal reliability test method under a multiple stress environment provided by the present application is shown in the figure.

[0022] In the figure: 1. Vibration table; 2. First fixed plate; 3. Fixed lug support; 4. Load connection structure rod; 5. First hydraulic cylinder; 6. Tension and compression sensor; 7. Second hydraulic cylinder; 8. Fixed structure; 9. Oil tank; 10. Oil pump; 11. Filter; 12. Heater; 13. Cooling fan; 14. Second fixed plate. Detailed Implementation

[0023] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0025] Example 1 like Figures 1-4 As shown, the present invention provides a reciprocating seal reliability testing device under multi-stress environment, including a hydraulic cylinder, a load hydraulic system, a stress loading system, a fixture assembly, and a testing system.

[0026] The hydraulic cylinder includes a cylinder barrel and a piston rod, with seals installed inside the cylinder barrel. A load hydraulic system supplies hydraulic fluid to the cylinder and regulates its pressure and temperature. A stress loading system includes a velocity loading module and a vibration loading module. The velocity loading module drives the piston rod in reciprocating motion, while the vibration loading module applies vibration stress to the seals. A fixture assembly secures the hydraulic cylinder; its first-order natural frequency is greater than 60Hz. A detection system collects and monitors the sealing performance parameters of the hydraulic cylinder in real time during the test. The hydraulic cylinder is mounted on the fixture assembly. The load hydraulic system applies load stress to the cylinder through pressure regulation. The stress loading system is connected to both the hydraulic cylinder and the fixture assembly, and the detection system is connected to the hydraulic cylinder. Through the synergistic action of the velocity loading module, the vibration loading module, and the load hydraulic system, comprehensive testing of the reciprocating seals under coupled velocity stress, vibration stress, and load stress is achieved, accurately simulating the actual service conditions of ship hydraulic cylinders.

[0027] In one specific embodiment of the present embodiment, the hydraulic cylinder includes a first hydraulic cylinder 5 and a second hydraulic cylinder 7. The rod end of the first hydraulic cylinder 5 is connected to a threaded rod through a tensile and compressive force sensor 6. The threaded rod is connected to the rod end of the second hydraulic cylinder 7 through a flange nut. The rod end of the first hydraulic cylinder 5 and the rod end of the second hydraulic cylinder 7 are fixed at the two ends of the clamp assembly, respectively. The tensile and compressive force sensor 6 has internal threads at both ends, and the rod ends of the two hydraulic cylinders are connected by screwing. The two hydraulic cylinders are arranged in an upper and lower butt joint configuration and work synchronously during the test to realize parallel testing of double samples, greatly shorten the test period and improve the test efficiency.

[0028] In one specific embodiment of the present embodiment, the speed loading module includes a servo motor, a frequency converter and a speed regulating device. The servo motor is connected to the hydraulic cylinder through the frequency converter and the speed regulating device in sequence. By controlling the speed of the servo motor, the speed of the piston rod is accurately controlled through the frequency converter and the speed regulating device, and the speed range is 0.005 m / s to 0.1 m / s.

[0029] In one specific embodiment of the present embodiment, the vibration loading module includes a vibration table 1, and the clamp assembly is fixed on the vibration table 1. The vibration table 1 drives the clamp assembly and the hydraulic cylinder to vibrate as a whole, simulating the vibration environment in the actual working condition.

[0030] In one specific embodiment of the present embodiment, the vibration table 1 generates vibration with a frequency range of 16 Hz to 60 Hz. The vibration table 1 can adjust the vibration frequency, amplitude and waveform parameters, and the vibration waveform is a sine wave, which meets the simulation requirements of the ship vibration environment.

[0031] In one specific embodiment of the present embodiment, the load hydraulic system includes an oil tank 9, an oil pump 10, a filter 11, a heater 12, a cooling fan 13 and an electro-hydraulic servo valve. The heater 12 and the cooling fan 13 are connected to the oil tank 9 respectively for adjusting the oil temperature. The oil tank 9 is connected to the inlet of the oil pump 10 through the filter 11, and the outlet of the oil pump 10 is connected to the rod cavity and / or the rodless cavity of the hydraulic cylinder through the electro-hydraulic servo valve. The electro-hydraulic servo valve accurately controls the oil pressure entering the cavities of the hydraulic cylinder to realize the application of load stress, and the pressure regulation range is 1 MPa to 25 MPa. The heater 12 and the cooling fan 13 work in coordination to accurately control the oil temperature within the preset range.

[0032] In one specific embodiment of the present embodiment, the detection system includes sensors and a data acquisition and analysis unit connected in sequence, and the sensors are installed on the hydraulic cylinder. The sensors collect real-time sealing performance related parameters, and the data acquisition and analysis unit converts the collected analog signals into digital signals and processes and analyzes them.

[0033] In one specific embodiment of the present embodiment, the sensors include a vibration sensor, an oil temperature sensor, and a tension and compression force sensor 6. The vibration sensor is installed on the vibration loading module, the clamp assembly, and the hydraulic cylinder to monitor the transmission of vibration stress in the test device. The oil temperature sensor is installed on the oil pipeline of the load hydraulic system to monitor the real-time change of oil temperature. The tension and compression force sensor 6 is installed between the rod end of the first hydraulic cylinder 5 and the rod end of the second hydraulic cylinder 7, which not only serves as a connection but also monitors the tension and compression load between the two hydraulic cylinders in real time. Through the cooperation of multiple types of sensors, comprehensive monitoring of speed, vibration, load, and other multi-stress parameters during the test process is achieved.

[0034] In one specific embodiment of the present embodiment, the clamp assembly includes a first fixed plate 2, a second fixed plate 14, and a plurality of load connection structure rods 4, and the first fixed plate 2 and the second fixed plate 14 are fixedly connected through the load connection structure rods 4. The rodless end of the first hydraulic cylinder 5 is fixed on the first fixed plate 2, and the rodless end of the second hydraulic cylinder 7 is fixed on the second fixed plate 14. The overall structure is installed on the vibration table 1 through the first fixed plate 2. The first fixed plate 2 is provided with a fixed ear support 3 for fixing the first hydraulic cylinder 5, and the second fixed plate 14 is provided with a fixed structure 8 for improving the stability of the overall clamp assembly. The clamp assembly is made of high-strength steel material and has high rigidity and light weight characteristics through reasonable structural design. After testing, the first-order natural frequency of the clamp assembly reaches 74 Hz, and the static load strength meets the requirements of the marine environmental conditions, which can effectively avoid resonance in the vibration test of 16 Hz-60 Hz and ensure the stability of the test platform.

[0035] Embodiment 2 As Figure 5As shown, the application also provides a reciprocating sealing reliability test method using the above device, which comprises the following steps. First, the hydraulic cylinder to be tested is installed in the fixture assembly, the rod end of the lower hydraulic cylinder is connected to the rod end of the upper hydraulic cylinder through the tensile and compressive force sensor, the two rodless ends of the hydraulic cylinders are fixed on the upper and lower ends of the fixture respectively, and the entire fixture and the hydraulic cylinder test piece are placed on the vibration table through the lower fixed table. Then, the pressure and temperature of the oil are adjusted to the preset value through the load hydraulic system, and the oil ports of the rod cavities and the rodless cavities of the upper and lower hydraulic cylinders are connected to the electro-hydraulic servo valve in the load hydraulic system through high-pressure oil pipes. Next, the stress loading system is used to apply acceleration stress and vibration stress to the hydraulic cylinder, the load hydraulic system is used to adjust the oil pressure to apply load stress to the hydraulic cylinder, the reciprocating speed of the test piece is accurately controlled by the hydraulic oil flow, the vibration is accurately simulated by adjusting the vibration frequency and amplitude of the vibration table as needed, and the load is applied by finely adjusting the oil pressure with the help of the electro-hydraulic servo valve. At the same time, the sealing performance parameters of the hydraulic cylinder are collected in real time by the detection system, including the load, vibration frequency and acceleration, reciprocating speed of the test hydraulic cylinder, and the leakage amount of the hydraulic cylinder oil, the wear amount of the sealing ring and other data. Finally, the performance degradation state and reliability of the reciprocating seal are evaluated according to the collected sealing performance parameters, which provides a basis for the life prediction and reliability design of the reciprocating seal of the ship hydraulic cylinder.

[0036] In one specific embodiment of the present embodiment, the acceleration stress is applied by adjusting the speed of the servo motor, the vibration stress is applied by adjusting the vibration frequency and amplitude of the vibration table, and the load stress is applied by adjusting the oil pressure with the electro-hydraulic servo valve. The three stresses are independently controllable and are applied cooperatively, which truly reproduces the service environment of the ship hydraulic cylinder under multi-stress coupling conditions. After the rod ends of the two test hydraulic cylinders are connected stably, the two cylinders are realized to be top-to-top and reciprocating up and down under the action of the test table, and the two hydraulic cylinders complete the performance degradation test of the seal in the same test period.

[0037] During the test process, the two hydraulic cylinders complete the wear failure test of the seal in the same test period. Through the above test device and method, the service environment of the ship hydraulic cylinder under multi-stress coupling conditions such as high pressure, vibration and load fluctuation can be truly simulated, and the fatigue life data of the reciprocating seal under specific service conditions can be obtained, which provides a basis for the reliability design of the hydraulic reciprocating seal.

[0038] The above embodiments are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and implement it, and cannot limit the protection scope of the present application. Any equivalent transformation or modification made according to the spirit and essence of the present application should be covered within the protection scope of the present application.

Claims

1. A device for testing the reliability of reciprocating seals under a multi-stress environment, characterized in that: The hydraulic cylinder comprises a cylinder barrel and a piston rod connected in sequence, and a sealing element is arranged in the cylinder barrel. A load hydraulic system is arranged to supply oil to the hydraulic cylinder and adjust the pressure and temperature of the oil, and the load hydraulic system applies load stress to the hydraulic cylinder through pressure adjustment. A stress loading system comprises a speed loading module and a vibration loading module, the speed loading module is arranged to drive the piston rod to reciprocate, and the vibration loading module is arranged to apply vibration stress to the sealing element. A clamp assembly is arranged to fix the hydraulic cylinder, and the first-order natural frequency of the clamp assembly is greater than 60 Hz. A detection system is arranged to collect and monitor the sealing performance parameters of the hydraulic cylinder in real time during the test. The hydraulic cylinder is mounted on the clamp assembly, the stress loading system is connected with the hydraulic cylinder and the clamp assembly respectively, and the detection system is connected with the hydraulic cylinder. The hydraulic cylinder comprises a first hydraulic cylinder and a second hydraulic cylinder, the piston rod end of the first hydraulic cylinder is connected with the piston rod end of the second hydraulic cylinder through a tension and compression force sensor, a threaded rod and a flange nut in sequence, and the non-piston rod end of the first hydraulic cylinder and the non-piston rod end of the second hydraulic cylinder are fixed on the two ends of the clamp assembly respectively.

2. The device according to claim 1, characterized in that: The speed loading module comprises a servo motor, a frequency converter and a speed regulating device, and the servo motor is connected with the hydraulic cylinder through the frequency converter and the speed regulating device in sequence.

3. The device according to claim 1, characterized in that: The vibration loading module comprises a vibration table, and the clamp assembly is fixed on the vibration table.

4. The device according to claim 1, characterized in that: The vibration table generates vibration with a frequency range of 16 Hz-60 Hz.

5. The device according to claim 4, wherein: The load hydraulic system comprises an oil tank, an oil pump, a filter, a heater, a cooling fan and an electro-hydraulic servo valve, the heater and the cooling fan are connected with the oil tank respectively, the oil tank is connected with the inlet of the oil pump through the filter, and the outlet of the oil pump is connected with the cylinder barrel of the hydraulic cylinder through the electro-hydraulic servo valve.

6. The device according to claim 1, wherein: The detection system comprises sensors and a data acquisition and analysis unit connected with each other.

7. The device according to claim 2, wherein: The sensors comprise vibration sensors, oil temperature sensors and tension and compression force sensors, the vibration sensors are mounted on the vibration loading module, the clamp assembly and the hydraulic cylinder, the oil temperature sensors are mounted on the oil pipeline of the load hydraulic system, and the tension and compression force sensors are mounted between the piston rod end of the first hydraulic cylinder and the piston rod end of the second hydraulic cylinder and play a connecting role.

8. The device according to claim 7, characterized in that: The clamp assembly comprises a first fixed plate, a second fixed plate and a plurality of load connecting structure rods, the first fixed plate and the second fixed plate are fixedly connected through the load connecting structure rods, a fixed lug support is arranged on the first fixed plate, and a fixed structure is arranged on the second fixed plate.

9. The device according to claim 1, wherein: The method comprises the following steps:

10. A reciprocating seal reliability test method using the apparatus according to any one of claims 1 to 9, characterized by, S1: installing the hydraulic cylinder to be tested in the clamp assembly; S2: adjusting the pressure and temperature of the oil to the preset value through the load hydraulic system; S3: applying speed stress and vibration stress to the hydraulic cylinder through the stress loading system, and applying load stress to the hydraulic cylinder through the load hydraulic system. ​ S4: Real-time acquisition of the sealing performance parameters of the hydraulic cylinder through the detection system; S5: Evaluation of the performance degradation state and reliability of the reciprocating seal according to the collected sealing performance parameters.

Images