Wet clutch static pressure fatigue test method and system
By combining a hydraulic unit, a temperature control unit, and a multi-parameter acquisition unit, high-precision testing of wet clutches under complex working conditions is achieved, solving the problem of large deviations in test results in existing technologies, and providing early failure warnings and accurate durability assessments.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-30
- Publication Date
- 2026-04-14
AI Technical Summary
Existing fatigue testing methods for wet clutches lack simulation of complex working conditions, resulting in significant deviations between test results and actual working conditions. Furthermore, the accuracy of durability prediction is low, failing to provide reliable early warning of failure.
By employing a hydraulic unit, a temperature regulation unit, a multi-parameter acquisition unit, and a control unit, high-precision coordinated control and synchronous monitoring of multiple parameters are achieved. Combined with dynamic characteristic comparison tests before and after fatigue and degradation modeling, various complex working conditions are simulated to reveal the degradation law of wet clutches under long-term static clamping conditions.
It enables in-situ, online monitoring of wet clutch performance degradation, improves testing accuracy and efficiency, provides early failure warnings, reveals the intrinsic relationship between static fatigue and dynamic performance, and supports performance optimization and maintenance strategies.
Smart Images
Figure CN121855868A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of wet clutch testing technology, specifically relating to a method and system for static pressure fatigue testing of wet clutches. Background Technology
[0002] Wet clutches, with their superior lubrication, efficient cooling, and automatic cleaning functions when operating in an oil environment, effectively solve the problems of overheating and severe wear of dry clutches. Therefore, they are widely used in fields with high requirements for transmission stability, such as automotive automatic transmissions, hydraulic torque converters for construction machinery, and marine main engine transmission systems.
[0003] However, wet clutches operate by being immersed in oil, which serves multiple functions including lubrication, cooling, and cleaning. This also introduces complex hydrodynamic effects, such as oil film shear, pressure loss, thermal convection, the degree of engagement of the wet clutch, and the amount of oil filling the piston. Consequently, under long-term static compression, the core components of a wet clutch are prone to various degradation and failure modes. Friction materials on friction plates experience wear, detachment, or thermal degradation due to prolonged pressure and oil immersion; seals suffer elastic deformation, cracking, or leakage due to long-term hydraulic pressure and oil aging; moving parts such as hydraulic valve cores and pistons experience wear from oil impurities and pressure impacts, leading to jamming or leakage. These degradation problems directly result in a significant decrease in the dynamic engagement characteristics of wet clutches, specifically manifested as increased engagement impact, longer response delay, and reduced torque transmission capacity, severely affecting the stability and reliability of the entire transmission system, and even causing safety accidents.
[0004] Therefore, conducting static pressure fatigue tests on wet clutches to accurately assess their durability level under long-term working conditions, and to reveal their fatigue degradation mechanism and dynamic response characteristics, is of great engineering significance and practical value for ensuring the safe operation of transmission systems and reducing maintenance costs.
[0005] In practical applications, when a wet clutch engages, the hydraulic unit or spring mechanism applies axial pressure, pressing the friction plates against the mating steel plates. Static pressure fatigue testing simulates the material property degradation (such as creep and plastic deformation) and seal failure under this long-term compression state.
[0006] However, existing fatigue testing methods for wet clutches mainly focus on verifying basic performance indicators, such as static clamping force holding capacity testing and simple cycle life testing under fixed working conditions. They generally lack the ability to simulate complex working conditions and conduct systematic and in-depth testing of the long-term durability of wet clutches.
[0007] Specifically, existing testing technologies have the following core shortcomings: First, the test conditions are designed in a single, fixed manner. Most test schemes only adopt a single cycle mode under fixed pressure, fixed temperature, and fixed flow rate, which is difficult to simulate the complex working conditions that wet clutches may face in actual applications, such as pressure fluctuations (e.g., pressure difference between idle speed and rated conditions), temperature changes (e.g., oil temperature range between cold start and long-term operation), and flow fluctuations (e.g., flow rate changes caused by hydraulic unit leakage). This results in a large deviation between the test results and the actual working conditions. Second, existing technologies mostly only record the number of test cycles and the final failure state. The durability prediction accuracy is low, and it cannot provide a reliable theoretical basis and data support for early failure warning of wet clutches.
[0008] Therefore, there is an urgent need for a method and system for static pressure fatigue testing of wet clutches that can fill the gaps in existing technologies, improve the accuracy and efficiency of static pressure fatigue testing of wet clutches, and provide strong technical support for the performance optimization, life prediction and operation and maintenance of wet clutches. Summary of the Invention
[0009] In view of this, the present invention provides a static pressure fatigue testing method and system for wet clutches, which can simulate various complex working conditions, realize high-precision coordinated control and synchronous monitoring of multiple parameters, and combine dynamic characteristic comparison test before and after fatigue and degradation modeling to reveal the degradation law of wet clutches under long-term static compression state, providing a reliable technical means for durability assessment and failure early warning of wet clutches.
[0010] The technical solution of this invention is: A method and system for static pressure fatigue testing of a wet clutch includes a hydraulic unit, a temperature control unit, a multi-parameter acquisition unit, and a control unit; wherein, The hydraulic unit includes an oil tank, an oil pump, and a proportional solenoid valve. The outlet of the oil pump is connected to the first port of the proportional solenoid valve, the inlet of the oil pump is connected to the oil tank, the second port of the proportional solenoid valve is used to connect to the wet clutch to provide controllable pressure to the wet clutch, and the third port of the proportional solenoid valve is connected to the oil tank for oil return during pressure relief. The temperature regulating unit is installed on the oil tank and is used to regulate the oil temperature; The multi-parameter acquisition unit is used to acquire multi-parameter data of the wet clutch in real time during the testing process; The control unit is electrically connected to the temperature regulation unit, the proportional solenoid valve, and the drive motor of the oil pump, respectively. It is used to control the speed of the drive motor of the oil pump, the opening degree of the proportional solenoid valve, and the working state of the temperature regulation unit, so as to realize the independent or combined regulation of test pressure, flow rate, and temperature to simulate various static pressure fatigue conditions. The control unit is also electrically connected to the multi-parameter acquisition unit to perform dynamic characteristic tests periodically or according to trigger conditions. It receives multi-parameter data from the multi-parameter acquisition unit in real time and determines the change of dynamic characteristic parameters. It compares the change of dynamic characteristic parameters with the failure warning threshold and generates a failure warning signal when the failure warning threshold is exceeded.
[0011] Furthermore, the temperature regulation unit includes a semiconductor cooling chip disposed on the outer periphery of the oil tank and a first temperature sensor disposed inside the oil tank. The first temperature sensor and the semiconductor cooling chip are electrically connected to the control unit.
[0012] Furthermore, the hydraulic unit also includes a check valve and a main pressure regulating valve. The outlet of the oil pump is connected to the inlet of the check valve. The outlet of the check valve is connected to the first port of the proportional solenoid valve and the first port of the main pressure regulating valve, respectively. The second port of the main pressure regulating valve is connected to the oil tank.
[0013] Furthermore, the hydraulic unit also includes an accumulator connected to the outlet of the check valve to maintain stable system pressure.
[0014] Furthermore, the hydraulic unit also includes a coarse oil filter and a fine oil filter. The coarse oil filter is located at the inlet of the oil pump, and the fine oil filter is located at the first port of the proportional solenoid valve.
[0015] Furthermore, the multi-parameter acquisition unit includes a displacement sensor, a pressure sensor, a first flow meter, a second flow meter, a level gauge, and a temperature sensing unit, all electrically connected to the control unit. The temperature sensing unit is used to synchronously monitor the oil temperature and the wet clutch temperature. The level gauge is installed on the oil tank to detect the oil level. The displacement sensor is installed on the mating disc or piston movement-related component of the wet clutch to obtain its movement distance. The pressure sensor is installed at the outlet of the one-way valve to detect the oil pressure at its location. The first flow meter is installed at the first port of the proportional solenoid valve, and the second flow meter is installed at the third port of the proportional solenoid valve to detect the oil flow rate at its location.
[0016] Furthermore, the temperature sensing unit includes a second temperature sensor disposed on the first port of the proportional solenoid valve and a third temperature sensor embedded in the wet clutch, wherein the second temperature sensor and the third temperature sensor are electrically connected to the control unit.
[0017] A method for static pressure fatigue testing of a wet clutch, based on the aforementioned static pressure fatigue testing system for wet clutches, includes the following steps: The wet clutch to be tested is mounted on the test bench and connected to the outlet of the proportional solenoid valve. Start the system and perform a static stress test. During the static stress test, perform dynamic characteristic tests periodically or according to trigger conditions. Throughout the test, the multi-parameter acquisition unit continuously acquires multi-parameter data in real time and transmits it synchronously to the control unit. The control unit processes the multi-parameter data in real time to determine the change in dynamic characteristic parameters and compares the change in dynamic characteristic parameters with the failure warning threshold. When the change in dynamic characteristic parameters exceeds the failure warning threshold, the control unit issues a failure warning signal.
[0018] Furthermore, when performing static stress testing, the following steps are included: Set target test conditions; The control unit adjusts the proportional solenoid valve to bring the pressure applied to the wet clutch to the target pressure, adjusts the speed of the oil pump drive motor to bring the flow rate of the hydraulic oil in the system to the target flow rate, controls the temperature regulation unit to bring the oil temperature of the hydraulic oil to the target temperature, and maintains static pressure to continuously load the wet clutch for a preset time.
[0019] Furthermore, when conducting dynamic characteristic testing, the following steps are included: The control unit periodically or according to triggering conditions controls the proportional solenoid valve to drive the wet clutch to perform a complete "engagement" and "disengagement" action under the same set pressure, flow rate and temperature conditions. The "joining" and "separating" actions are repeated multiple times at preset cycle intervals.
[0020] Compared with existing technologies, this invention provides a static pressure fatigue testing method and system for wet clutches, specifically applicable to the durability assessment, dynamic response characteristic degradation law analysis, and early failure warning of wet clutches under long-term static clamping conditions. It can provide accurate multi-parameter data support for wet clutch design optimization, production process improvement, and maintenance strategy formulation. The system provided by this invention utilizes a hydraulic unit to provide controllable hydraulic static pressure to the wet clutch, a temperature regulation unit to regulate oil temperature, and a multi-parameter acquisition unit to collect multi-parameter data of the wet clutch in real time during the testing process. A control unit is electrically connected to the temperature regulation unit, the multi-parameter acquisition unit, and the hydraulic unit to achieve independent or combined adjustment of test pressure, flow rate, and temperature to simulate various static pressure fatigue conditions. Simultaneously, it receives multi-parameter data from the multi-parameter acquisition unit in real time, determines the changes in dynamic characteristic parameters, compares the changes in dynamic characteristic parameters with a failure warning threshold, and generates a failure warning signal when the threshold is exceeded. This invention combines traditional static pressure fatigue testing with high-precision dynamic engagement characteristic monitoring. Through multi-parameter synchronous acquisition and correlation analysis, it achieves more scientific and accurate durability assessment and failure early warning. By combining the core technology of "dynamic and static combined testing concept + multi-parameter synchronous monitoring + failure early warning", it solves the blind spots of existing technologies, realizes in-situ and online monitoring of wet clutch performance degradation, greatly improves the accuracy and efficiency of testing, and provides early and accurate prediction of potential failure of wet clutches. It reveals the intrinsic connection between static fatigue and dynamic performance, thus surpassing the traditional "test-wait-failure" mode. It is highly practical and worthy of promotion. Attached Figure Description
[0021] Figure 1 This is a structural diagram of the hydraulic unit of the present invention.
[0022] Figure 2 This is a flowchart of the present invention.
[0023] Explanation of reference numerals in the attached figures: 1. First temperature sensor; 2. Level gauge; 3. Oil tank; 4. Coarse oil filter; 5. Drive motor for oil pump; 6. Oil pump; 7. Check valve; 8. Main pressure regulating valve; 9. Pressure sensor; 10. Accumulator; 11. First flow meter; 12. Second temperature sensor; 13. Fine oil filter; 14. Proportional solenoid valve; 15. Displacement sensor; 16. Third temperature sensor; 17. Wet clutch; 18. Second flow meter. Detailed Implementation
[0024] This invention provides a method and system for static pressure fatigue testing of wet clutches to solve the above-mentioned problems. In order to enable those skilled in the art to better understand the technical solution of this invention and to implement it, the technical solution of this invention will be clearly and thoroughly described below with reference to the accompanying drawings.
[0025] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" 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 this invention and simplifying the description, and are not intended to 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 this invention.
[0026] Furthermore, it should be further explained that in the description of the embodiments of the present invention, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The "and / or" in the text is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of the present invention, "multiple" means two or more.
[0027] The terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Thus, a feature defined as "first," "second," "third," or "fourth" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0028] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0029] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.
[0030] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this invention are for illustrative purposes only and do not represent the only possible implementation.
[0031] Example 1 A static pressure fatigue testing system for a wet clutch includes a hydraulic unit, a temperature control unit, a multi-parameter acquisition unit, and a control unit.
[0032] The structure of the hydraulic unit is as follows Figure 1 As shown, the hydraulic unit is used to provide static pressure to the wet clutch under test. The hydraulic unit includes an oil tank 3, an oil pump 6, a check valve 7, an accumulator 10, a main pressure regulating valve 8, and a proportional solenoid valve 14. The oil pump 6 is powered by a drive motor 5. The proportional solenoid valve, the drive motor 5, and the control unit are electrically connected. The check valve 7 is used to prevent liquid backflow. The proportional solenoid valve 14 is a two-position three-way solenoid valve. The first ports of the oil pump 6, the check valve 7, and the proportional solenoid valve 14 are connected in sequence. The inlet of the oil pump 6 is connected to the oil tank 3. The second port of the proportional solenoid valve 14 is used to connect to the wet clutch 17 to provide controllable hydraulic power to the wet clutch 17. The third port of the proportional solenoid valve 14 is connected to the oil tank 3 to return oil when pressure is released.
[0033] Furthermore, the first port of the main pressure regulating valve 8 is connected to the outlet of the check valve 7, and the second port of the main pressure regulating valve 8 is connected to the oil tank 3, which is used to adjust the pressure of the entire system.
[0034] Furthermore, the accumulator 10 is connected to the outlet of the check valve 7 to maintain stable system pressure.
[0035] Furthermore, the hydraulic unit also includes a coarse oil filter 4 and a fine oil filter 13 for achieving the filtration function. The coarse oil filter 4 is located at the inlet of the oil pump 6, and the fine oil filter 13 is located at the first port of the proportional solenoid valve 14.
[0036] The temperature control unit is located on the oil tank 3 and is used to regulate the temperature of the oil tank 3.
[0037] Specifically, the temperature regulation unit includes a thermoelectric cooler (TEC) disposed on the outer periphery of the oil tank 3 and a first temperature sensor 1 disposed inside the oil tank 3. The first temperature sensor 1 and the thermoelectric cooler (TEC) are electrically connected to the control unit. During use, the control unit performs control based on the real-time monitoring data of the first temperature sensor 1. The first temperature sensor 1 monitors the oil temperature in real time. When the oil temperature is lower than a preset lower threshold, the control unit applies a positive voltage to the thermoelectric cooler (TEC), causing one side to heat the oil tank contact surface while the heat is dissipated by a fan on the other side. When the oil temperature is higher than a preset upper threshold, the control unit reverses the voltage polarity of the thermoelectric cooler (TEC), causing the contact surface to absorb heat (cool), while the heat is dissipated from the other side.
[0038] The multi-parameter acquisition unit is used to acquire multi-parameter data of the wet clutch in real time during the testing process. Specifically, the multi-parameter acquisition unit includes a displacement sensor 15, a pressure sensor 9, a first flow meter 11, a second flow meter 18, a level gauge 2, a second temperature sensor 12, and a third temperature sensor 16, all of which are electrically connected to the control unit.
[0039] Specifically, the level gauge 2 is installed on the oil tank 3 to detect the oil level.
[0040] Specifically, the displacement sensor 15 is installed on the mating plate or piston movement associated component of the wet clutch 17 to obtain its movement distance.
[0041] Specifically, pressure sensor 9 is installed at the outlet of check valve 7 to detect the oil pressure at that location.
[0042] Specifically, the first flow meter 11 is installed at the first port of the proportional solenoid valve 14, and the second flow meter 18 is installed at the third port of the proportional solenoid valve 14, respectively for detecting the flow rate of oil at their respective locations.
[0043] Specifically, the second temperature sensor 12 is installed on the first port of the proportional solenoid valve 14 to detect the oil temperature at that position, and the third temperature sensor 16 is installed on the wet clutch 17 to detect the temperature at that position. The third temperature sensor 16 is preferably a thermocouple.
[0044] The function of the multi-parameter acquisition unit is: Dynamic displacement capture: A high-precision displacement sensor 15 is installed on the mating plate (or component associated with piston movement) of the wet clutch 17 to record the piston displacement-time curve in real time at a sampling rate of not less than 1 kHz. By performing real-time or subsequent differential calculations on this curve, the piston engagement speed v and acceleration a are accurately obtained.
[0045] Flow monitoring: A high-precision first flow meter 11 and a second flow meter 18 are installed at the oil inlet and / or oil outlet of the piston chamber of the wet clutch 17 to monitor the flow rate Q of oil filling or draining in real time.
[0046] Temperature field monitoring: The third temperature sensor 16 is embedded in a key part of the wet clutch 17 (such as near the mating plate or friction plate) to monitor the local temperature T in real time.
[0047] Pressure monitoring: Install pressure sensors 9 at key locations in the hydraulic pipeline (such as the main oil line and piston chamber inlet) to monitor the system pressure P in real time.
[0048] Temperature monitoring: The second temperature sensor 12 and the third temperature sensor 16 constitute a temperature sensing unit, which is used to realize the synchronous monitoring of oil temperature and the temperature of key parts of wet clutch respectively.
[0049] The control unit controls the speed of the drive motor 5 of the oil pump 6 in the hydraulic unit, the opening degree of the proportional solenoid valve 14, and the output temperature of the temperature regulation unit. This allows for independent or arbitrary combination adjustment of test pressure, flow rate, and temperature parameters to simulate various static pressure fatigue conditions. The control unit also receives multi-parameter data from the multi-parameter acquisition unit in real time and compares the failure warning threshold with the multi-parameter data. When the change in dynamic characteristic parameters exceeds the threshold, a failure warning is triggered.
[0050] Furthermore, the control unit can preferably employ a programmable operating condition simulation control component, specifically implemented using a PLC, and its expected basic functions are as follows: Pressure control: The system's base pressure P is set via the main pressure regulating valve 8. base The proportional solenoid valve 14 enables rapid and precise dynamic adjustment of oil pressure, achieving complex pressure curves such as pressure steps (e.g., 0MPa-5MPa), ramps, and pressure holding.
[0051] Flow control: The oil pump 6 is driven by the drive motor 5. The output flow rate Q of the oil pump 6 is changed by steplessly adjusting the speed of the drive motor 5, thereby controlling the flow rate of the oil entering the piston chamber of the wet clutch 17.
[0052] Temperature control: The temperature of oil tank 3 is regulated by controlling the temperature regulation unit on oil tank 3. The temperature regulation unit is equipped with heating and cooling functions. The temperature on oil tank 3 is monitored by the first temperature sensor 1, the inlet oil temperature is monitored by the second temperature sensor 12, and the key point temperature 16 of wet clutch 17 is monitored by the third temperature sensor 16, so as to achieve precise control and circulation of test oil temperature T (e.g., 20-120℃).
[0053] Operating condition combinations: The system supports independent or arbitrary combination of pressure P, flow rate Q, and temperature T for programmed settings and cycles, simulating various actual or accelerated static compression fatigue conditions.
[0054] Furthermore, such as Figure 2 As shown, the method for testing using the above system includes the following steps: The wet clutch 17 to be tested is mounted on the test bench and connected to the outlet of the proportional solenoid valve 14.
[0055] Start the system and perform a static stress test. During the static stress test, perform dynamic characteristic tests periodically or according to trigger conditions.
[0056] Throughout the test, the multi-parameter acquisition unit continuously collects displacement s(t), flow rate Q, pressure P, and temperature T in real time and transmits them synchronously to the control unit. The control unit processes the data in real time, analyzes the parameters collected during the dynamic characteristic test, calculates the changes in their dynamic characteristic parameters, and compares these changes with a failure warning threshold. When the changes in the dynamic characteristic parameters exceed the failure warning threshold, the control unit issues a failure warning signal.
[0057] The specific, detailed operating steps are as follows: The wet clutch 17 to be tested is installed on the test bench, the target test conditions are set, the system is started, and the drive motor 5 drives the oil pump 6 to start working.
[0058] Adjust the main pressure regulating valve 8 and the proportional solenoid valve 14 to the target pressure P0, adjust the speed of the drive motor 5 to the target flow rate Q0, and control the temperature of the oil tank 3 to the target temperature T0.
[0059] During the static pressure P holding period (i.e., simulating a long-term compressed state), the system continues to operate. Accumulator 10 is used to maintain system pressure stability.
[0060] Core monitoring process: Throughout the entire test process (including before and after fatigue cycles), the system synchronously and continuously collects and records data such as displacement s(t), flow rate Q, pressure P, and temperature T, and calculates the velocity v(t) = ds / dt and acceleration a(t) = dv / dt in real time or after processing.
[0061] Dynamic characteristic test (comparison before and after fatigue): Before and after the fatigue test (or at a specific cycle interval), under the same set pressure P, flow rate Q, and temperature T, perform a complete "engagement" action of the wet clutch 17, and record the displacement s(t), velocity v(t), and acceleration a(t) curves of this action with high precision.
[0062] By comparing the dynamic response curves before and after fatigue, such as engagement time, maximum velocity v_max, and maximum acceleration a_max under specific pressure and flow rates, the impact of fatigue degradation on dynamic performance (Δv, Δa) is quantified.
[0063] Correlation modeling and failure early warning: Pressure (P) stability analysis: During the set static pressure holding phase, analyze the pressure fluctuation range (P_fluctuation = P_max - P_min) and pressure decay rate (dP / dt). Trend judgment: If P_fluctuation increases or an unsustainable negative dP / dt occurs, it indicates that the hydraulic unit's sealing performance has decreased or leakage exists.
[0064] Flow (Q) Balance Analysis: Real-time comparison of the proportional valve inlet flow rate Q_in with the flow rate Q_out (or return oil flow rate) from the outlet to the wet clutch 17. Calculate the instantaneous leakage ΔQ = Q_in - Q_out. Trend Judgment: ΔQ shows a monotonically increasing trend with test time, which is direct evidence of wear and aging of the piston seal or static seal ring.
[0065] Displacement (s) retention analysis: Under long-term compression, monitor the piston displacement drift Δs. Trend judgment: A continuous positive increase in Δs (piston retraction) may indicate creep of the friction material or further extrusion of the oil film, while abnormal negative changes may be associated with other mechanical loosening.
[0066] Temperature (T) field analysis: Monitor the temperature difference ΔT between key points (such as near the friction plates) and the ambient oil temperature. Trend judgment: Under the same heat dissipation conditions, an increase in ΔT may indicate an increase in the thermal resistance of the friction pair, a deterioration in the local contact condition, or obstruction of the cooling oil passages.
[0067] Dynamic parameters (v, a) benchmark comparison: This is a core performance indicator. The control unit periodically or according to triggering conditions controls the proportional solenoid valve 14 to perform an "engagement" action under exactly the same calibration conditions, obtains the displacement curve s(t), and then calculates the peak speed v_max and peak acceleration a_max. Trend judgment: Comparing v_max and a_max from previous tests, their decay trend directly reflects the degradation of the dynamic response capability of the wet clutch 17.
[0068] A multi-parameter failure warning threshold is set, and the multi-parameter data (P, Q, T, v, a) collected during the long-term static compression process are compared with the failure warning threshold. When the change in dynamic characteristic parameters exceeds the failure warning threshold, the system can issue a warning, indicating that sealing failure or severe material degradation may occur.
[0069] Compared with existing technologies, this invention provides a static pressure fatigue testing method and system for wet clutches, specifically applicable to the durability assessment, dynamic response characteristic degradation law analysis, and early failure warning of wet clutches under long-term static clamping conditions. It can provide accurate multi-parameter data support for wet clutch design optimization, production process improvement, and maintenance strategy formulation. The system provided by this invention utilizes a hydraulic unit to provide controllable hydraulic static pressure to the wet clutch, a temperature regulation unit to regulate oil temperature, and a multi-parameter acquisition unit to collect multi-parameter data of the wet clutch in real time during the testing process. A control unit is electrically connected to the temperature regulation unit, the multi-parameter acquisition unit, and the hydraulic unit to achieve independent or combined adjustment of test pressure, flow rate, and temperature to simulate various static pressure fatigue conditions. Simultaneously, it receives multi-parameter data from the multi-parameter acquisition unit in real time, determines the changes in dynamic characteristic parameters, compares the changes in dynamic characteristic parameters with a failure warning threshold, and generates a failure warning signal when the threshold is exceeded. This invention combines traditional static pressure fatigue testing with high-precision dynamic engagement characteristic monitoring. Through multi-parameter synchronous acquisition and correlation analysis, it achieves more scientific and accurate durability assessment and failure early warning. By combining the core technology of "dynamic and static combined testing concept + multi-parameter synchronous monitoring + failure early warning", it solves the blind spots of existing technologies, realizes in-situ and online monitoring of wet clutch performance degradation, greatly improves the accuracy and efficiency of testing, and provides early and accurate prediction of potential failure of wet clutches. It reveals the intrinsic connection between static fatigue and dynamic performance, thus surpassing the traditional "test-wait-failure" mode. It is highly practical and worthy of promotion.
[0070] The above-disclosed embodiments are merely preferred embodiments of the present invention. However, the embodiments of the present invention are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.
Claims
1. A static pressure fatigue testing system for a wet clutch, characterized in that, It includes a hydraulic unit, a temperature control unit, a multi-parameter acquisition unit, and a control unit; among which, The hydraulic unit includes an oil tank, an oil pump, and a proportional solenoid valve. The outlet of the oil pump is connected to the first port of the proportional solenoid valve, the inlet of the oil pump is connected to the oil tank, the second port of the proportional solenoid valve is used to connect to the wet clutch to provide controllable pressure to the wet clutch, and the third port of the proportional solenoid valve is connected to the oil tank for oil return during pressure relief. The temperature regulating unit is installed on the oil tank and is used to regulate the oil temperature; The multi-parameter acquisition unit is used to acquire multi-parameter data of the wet clutch in real time during the testing process; The control unit is electrically connected to the temperature regulation unit, the proportional solenoid valve, and the drive motor of the oil pump, respectively. It is used to control the speed of the drive motor of the oil pump, the opening degree of the proportional solenoid valve, and the working state of the temperature regulation unit, so as to realize the independent or combined regulation of test pressure, flow rate, and temperature to simulate various static pressure fatigue conditions. The control unit is also electrically connected to the multi-parameter acquisition unit to perform dynamic characteristic tests periodically or according to trigger conditions. It receives multi-parameter data from the multi-parameter acquisition unit in real time and determines the change of dynamic characteristic parameters. It compares the change of dynamic characteristic parameters with the failure warning threshold and generates a failure warning signal when the failure warning threshold is exceeded.
2. The wet clutch static pressure fatigue testing system according to claim 1, characterized in that, The temperature regulation unit includes a semiconductor cooling chip disposed on the outer periphery of the oil tank and a first temperature sensor disposed inside the oil tank. The first temperature sensor and the semiconductor cooling chip are electrically connected to the control unit.
3. The wet clutch static pressure fatigue testing system according to claim 1, characterized in that, The hydraulic unit also includes a check valve and a main pressure regulating valve. The outlet of the oil pump is connected to the inlet of the check valve. The outlet of the check valve is connected to the first port of the proportional solenoid valve and the first port of the main pressure regulating valve, respectively. The second port of the main pressure regulating valve is connected to the oil tank.
4. The wet clutch static pressure fatigue testing system according to claim 3, characterized in that, The hydraulic unit also includes an accumulator connected to the outlet of the check valve to maintain stable system pressure.
5. The wet clutch static pressure fatigue testing system according to claim 4, characterized in that, The hydraulic unit also includes a coarse oil filter and a fine oil filter. The coarse oil filter is located at the inlet of the oil pump, and the fine oil filter is located at the first port of the proportional solenoid valve.
6. The wet clutch static pressure fatigue testing system according to claim 5, characterized in that, The multi-parameter acquisition unit includes a displacement sensor, a pressure sensor, a first flow meter, a second flow meter, a level gauge, and a temperature sensing unit, all electrically connected to the control unit. The temperature sensing unit is used to synchronously monitor the oil temperature and the wet clutch temperature. The level gauge is installed on the oil tank to detect the oil level. The displacement sensor is installed on the mating disc or piston movement-related component of the wet clutch to obtain its movement distance. The pressure sensor is installed at the outlet of the one-way valve to detect the oil pressure at its location. The first flow meter is installed at the first port of the proportional solenoid valve, and the second flow meter is installed at the third port of the proportional solenoid valve to detect the oil flow rate at its location.
7. The wet clutch static pressure fatigue testing system according to claim 6, characterized in that, The temperature sensing unit includes a second temperature sensor disposed on the first port of the proportional solenoid valve and a third temperature sensor embedded in the wet clutch, wherein the second temperature sensor and the third temperature sensor are electrically connected to the control unit.
8. A method for static pressure fatigue testing of a wet clutch, based on the static pressure fatigue testing system for a wet clutch as described in claim 7, characterized in that, Includes the following steps: The wet clutch to be tested is mounted on the test bench and connected to the outlet of the proportional solenoid valve. Start the system and perform a static stress test. During the static stress test, perform dynamic characteristic tests periodically or according to trigger conditions. Throughout the test, the multi-parameter acquisition unit continuously acquires multi-parameter data in real time and transmits it synchronously to the control unit. The control unit processes the multi-parameter data in real time to determine the change in dynamic characteristic parameters and compares the change in dynamic characteristic parameters with the failure warning threshold. When the change in dynamic characteristic parameters exceeds the failure warning threshold, the control unit issues a failure warning signal.
9. The method for static pressure fatigue testing of a wet clutch according to claim 8, characterized in that, When performing static stress testing, the following steps are included: Set target test conditions; The control unit adjusts the proportional solenoid valve to bring the pressure applied to the wet clutch to the target pressure, adjusts the speed of the oil pump drive motor to bring the flow rate of the hydraulic oil in the system to the target flow rate, controls the temperature regulation unit to bring the oil temperature of the hydraulic oil to the target temperature, and maintains static pressure to continuously load the wet clutch for a preset time.
10. The method for static pressure fatigue testing of a wet clutch according to claim 8, characterized in that, When performing dynamic characteristic testing, the following steps are included: The control unit periodically or according to triggering conditions controls the proportional solenoid valve to drive the wet clutch to perform a complete "engagement" and "disengagement" action under the same set pressure, flow rate and temperature conditions. The "joining" and "separating" actions are repeated multiple times at preset cycle intervals.