A method for testing the durability of a hydraulic pump for underwater acoustic equipment

Abstract

The application discloses a kind of hydraulic pump durability test methods for underwater acoustic equipment, provide a kind of plunger pump durability test method, from test load spectrum design, load spectrum cycle number design, test loading loop design, test process monitoring parameter design, state monitoring in test, test post-inspection, plunger pump failure determination criterion etc. The durability of plunger pump long-time operation is evaluated, whether plunger pump meets the use demand is judged.Simultaneously provide a kind of screw pump durability test method, according to screw pump durability load spectrum, the loading loop of screw pump is designed, realizes screw pump durability load spectrum stepless automatic regulation;According to the working characteristics of screw pump in equipment, determine the allowable decline range of screw pump performance parameter, formulate screw pump durability test result determination criterion.The durability test judges whether the screw pump durability meets the use demand of user, the problem existing in long-term use of screw pump is found in time, avoid frequent failure in actual use process.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of hydraulic test, and particularly relates to a hydraulic pump durability test method for underwater acoustic equipment. BACKGROUND

[0002] The hydraulic pump is an important energy conversion element in the hydraulic transmission system, mainly including a plunger pump and a screw pump.

[0003] The plunger pump has the advantages of high parameters, high efficiency, long service life, convenient variable, large power density and the like. The plunger pump is mainly used for the main oil circuit and the control oil circuit of the pump station, can provide high-pressure oil and control oil for the hydraulic system, and is a key device for the work of the hydraulic system.

[0004] In the existing plunger pump test standard, general technical conditions of the plunger pump, test methods and test procedures for performance test of the plunger pump at the factory are specified, such as the national standard GB / T18492-2018 "General Technical Conditions for Plunger Pumps", JB / T5299-2007 "Test Methods for Plunger Pumps", and HG / T4576-2013 "Performance Test Procedures for Plunger Pumps". However, there is no general standard method for verifying the service life of the plunger pump under the specified use and maintenance conditions, the durability test method of the weak links and dangerous positions of the structure, and the failure judgment criterion. There is also no related standard method for accelerating the aging of the plunger pump and verifying the durability of the test parts.

[0005] The screw pump has the advantages of large output flow, small running noise, compact size, light weight, high reliability and the like. The screw pump is mainly used for the hydraulic circulation loop, can complete the replacement of the hydraulic oil in the hydraulic oil tank in a short time, cooperates with the filtering device and the heat exchange device to jointly realize the cleaning and filtering of the hydraulic oil and the temperature control, and assists in ensuring that various indexes of the hydraulic oil meet the requirements of the hydraulic system, which is crucial for the reliable operation of the hydraulic system.

[0006] In the existing screw pump test standard, test methods for performance test of the screw pump at the factory are specified, such as the national standard GB / T11705-2009 "Test Methods for Electric Three-screw Pumps for Ships". However, there is no general standard method for verifying the service life of the screw pump under the specified use and maintenance conditions, the durability test method of the weak links and dangerous positions of the structure, and the failure judgment criterion. There is also no related standard method for accelerating the aging of the screw pump and verifying the durability of the test parts.

[0007] How to scientifically and reliably conduct the durability test of the hydraulic pump and test the durability of the hydraulic pump is of great significance for guiding the optimized design of the hydraulic pump and the selection and use of subsequent products. Therefore, a hydraulic pump durability test method for underwater acoustic equipment needs to be designed to timely find out problems existing in the long-term use of the hydraulic pump and make corresponding optimization and improvement to avoid frequent failures in the actual test process. SUMMARY

[0008] The application aims to provide a scientific, reliable, practical and effective hydraulic pump durability test method for water acoustic equipment, so as to evaluate the durability of the hydraulic pump in long-time operation and determine whether the hydraulic pump meets the user's requirements.

[0009] The application aims to provide a scientific, reliable, practical and effective hydraulic pump durability test method for water acoustic equipment, so as to evaluate the durability of the hydraulic pump in long-time operation and determine whether the hydraulic pump meets the user's requirements.

[0010] As a preferred technical solution, the hydraulic pump is a screw pump, and the specific steps include:

[0011] A. According to the actual working task profile and the margin coefficient of the screw pump, the screw pump durability test load spectrum is formulated based on the "equal work principle", and the screw pump durability test load spectrum is composed of the cycle number and the spectrum curve of one cycle;

[0012] A1. The cycle number of the durability test load spectrum is calculated as follows:

[0013] n=T / T0

[0014] T=K*A0*H

[0015] In the formula, A0 is the working time of the equipment one task profile screw pump, H is the total working number required by the equipment; K is the equipment margin coefficient; T is the total running time of the screw pump; T0 is the one cycle time of the durability load spectrum spectrum curve; n is the cycle number of the durability load spectrum;

[0016] A2. The one cycle spectrum curve of the durability load spectrum is determined according to the spectrum curve when the screw pump runs once during the equipment operation, which is determined by the related parameters of the screw pump speed, outlet pressure and outlet flow; the spectrum curve is accelerated by using the "equal work principle", that is, the screw pump power is improved and the time is shortened to ensure that the screw pump does the same work; the screw pump output power can be improved by keeping the screw pump speed unchanged and improving the screw pump outlet pressure grade, so as to shorten the one cycle time of the screw pump.

[0017] B. According to the screw pump durability test load spectrum, the loading circuit of the screw pump is designed to realize stepless automatic adjustment of the screw pump durability test load spectrum;

[0018] C. According to the working characteristics of the screw pump in the equipment, the allowable decline range of the performance parameters of the screw pump is determined, and the screw pump durability test result determination criterion is formulated.

[0019] Further, the loading circuit is a proportional overflow valve added in the screw pump output oil circuit to adjust the screw pump output pressure, so that the stepless adjustment of the screw pump durability test load spectrum is realized, and the stepless adjustment and closed loop control of the screw pump rated flow and volumetric efficiency related performance test load spectrum can also be met.

[0020] Further, the screw pump durability test spectrum curve is affected by the oil temperature and has a certain deviation from the theoretical load spectrum, but the deviation should not exceed ±5% of the theoretical load spectrum; the load screw pump durability test judgment criterion includes the leakage during the whole screw pump durability test process, the decrease of the screw pump output flow under the working pressure grade of not more than 3% before and after the durability test, and no obvious wear or deformation of the screw after disassembly.

[0021] As a preferred technical solution, the hydraulic pump is a plunger pump, and the specific steps include:

[0022] A. According to the plunger pump working task profile and alternating load, the plunger pump durability test load spectrum is formulated, the load spectrum cycle number is calculated combined with the "equal work principle" and the margin coefficient, so as to determine the test process parameters;

[0023] T=K·A0·H

[0024] n=T / T0

[0025] In the formula, A0 is the working time of the plunger pump per working time of the equipment, H is the required working number of the equipment; K is the margin coefficient; T is the total working time of the plunger pump; T0 is the cycle time of the load spectrum; and n is the cycle number of the load spectrum;

[0026] B. According to the plunger pump function and the load spectrum, the loading circuit is designed: according to the plunger pump durability test load spectrum determined in step A, the maximum working flow, the maximum working pressure, the maximum speed of the plunger pump circuit and the plunger pump hydraulic circuit loading and flow control mode are determined, so that the pressure and flow in the load spectrum can be reached in the test; the pump head pressure is adjusted by the proportional overflow valve in the loading circuit, and the plunger pump output flow is adjusted by the motor, so that the design pressure and flow of the load spectrum are realized;

[0027] C. The failure wear, fatigue and sealing aging mechanism of the plunger pump are analyzed, the type of abnormal phenomenon of the plunger pump is inferred, and the parameters that need to be monitored in the plunger pump durability process are determined;

[0028] D. Test steps: installation, cleaning and trial operation before test to ensure no fault; during the test, the parameters are monitored, and the performance test is carried out; during the test, the changes of the no-load displacement, constant power pressure flow curve and efficiency characteristic are checked; after the test, the performance test and disassembly inspection are carried out;

[0029] E, according to the test result determination criterion, whether the plunger pump meets the user's demand is analyzed and determined.

[0030] Further, the load spectrum mainly comprises working pressure, working flow, section working time of the plunger pump, in the process of making the load spectrum, the test acceleration parameters are set according to the user's needs in combination with the failure mode of the plunger pump, and the durability test is accelerated.

[0031] Further, the abnormal phenomena of the plunger pump mainly include that the pump cannot be normally started, the pump flow is insufficient, abnormal noise, working medium leakage and pump body temperature being too high, and the monitored parameters mainly include leakage, rotating speed, flow, pressure, pump body temperature, abnormal sound, medium temperature and oil cleanliness.

[0032] Further, the step E specifically comprises:

[0033] E1, state determination in the test: no leakage, no abnormal pump body temperature, no abnormal sound, meeting the requirements of the load spectrum, meeting the requirements of cleanliness, meeting the requirements of time, and the performance inspection in the test meeting the requirements;

[0034] E2, performance inspection: the no-load displacement, efficiency characteristic and constant power pressure flow curve meet the requirements, the output flow of the plunger pump is reduced by not more than 3%, no oil leakage and no leakage;

[0035] E3, part wear inspection: after the test, the plunger pump is disassembled and inspected, mainly to check the wear condition, and the requirements are as follows: no obvious wear or deformation of the plunger pair, no obvious deformation of the sealing element, and no visible cracks in the pump body.

[0036] Further, the test result determination criterion is comprehensively analyzed from three angles of data analysis in the test process, performance of the plunger pump before, during and after the test, and disassembly of the plunger pump after the test, and covers the abnormal phenomena of the plunger pump.

[0037] The beneficial effects of the present application are as follows: compared with the existing hydraulic pump test technology, the hydraulic pump durability test method of the present application is accurate and effective through scientific analysis, combination of the functional characteristics of the hydraulic pump, user use characteristics, failure mode and the like, fills the blank of the hydraulic pump durability test method, perfects the hydraulic pump durability test examination system, can effectively test the use durability of the hydraulic pump, can test whether the hydraulic pump meets the user's use demand before actual use, and through the durability test, problems are found out, the design and optimization of the hydraulic pump product are guided, and the risk of the user in the hydraulic pump product is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 It is a screw pump durability test step flow chart in embodiment 1 of the present application;

[0039] Figure 2The screw pump durability test load spectrum curve prepared in the embodiment 1 of the present application;

[0040] Figure 3 The hydraulic loading circuit designed for the screw pump durability test load spectrum in the embodiment 1 of the present application;

[0041] Figure 4 The screw pump durability test failure judgment flow chart in the embodiment 1 of the present application.

[0042] Figure 5 The plunger pump durability test step flow chart in the embodiment 2 of the present application;

[0043] Figure 6 The plunger pump durability test task profile load prepared in the embodiment 2 of the present application;

[0044] Figure 7 The hydraulic loading circuit designed for the plunger pump durability test load spectrum in the embodiment 2 of the present application;

[0045] Figure 8 The plunger pump durability test monitoring parameter framework chart in the embodiment 2 of the present application;

[0046] Figure 9 The plunger pump durability test failure judgment flow chart in the embodiment 2 of the present application. DETAILED DESCRIPTION

[0047] In order for those skilled in the art to better understand the technical solutions of the present application, the preferred embodiments of the present application are described below in combination with the drawings and specific embodiments, but it should be understood that the drawings are only used for illustrative description and cannot be understood as a limitation on the present application; in order to better illustrate the embodiments, some components in the drawings may be omitted, enlarged or reduced, and do not represent the actual product size; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted. The positional relationship described in the drawings is only used for illustrative description and cannot be understood as a limitation on the present application.

[0048] Embodiment 1:

[0049] The screw pump has the characteristics of low speed, simple structure, large flow, high efficiency and strong anti-pollution ability, and is used as an oil tank circulating cooling pump in the hydraulic system of a water sound equipment. According to the number of screws, it can be divided into single screw pump, double screw pump and triple screw pump, and the present patent is a triple screw pump, which is mainly composed of a bushing in the pump body, one driving screw and two driven screws.

[0050] When the screw pump works, the motor drives the driving screw to rotate, the two driven screws are symmetrically engaged with the driving screw and follow the rotation, the engagement between the driving and driven screws forms a sealed cavity, and the sealed cavity is formed from the oil suction port and moves to the oil discharge port for release, so that the mechanical structure rotation is converted into the pressure and flow of the oil source.

[0051] The key friction pairs of the screw pump include the engagement friction pairs between the driving and driven screws and the friction pairs between the screw and the pump body, and the matching state of the key friction pairs has an important influence on the performance of the screw pump.

[0052] The embodiment discloses a screw pump durability test method for underwater acoustic equipment, which comprises the following steps: Figure 1 The specific steps of the screw pump durability test method are shown in the flowchart, and specifically include the following steps:

[0053] A, the screw pump durability load spectrum design, the screw pump durability load spectrum is composed of cycle number and spectrum curve of one cycle.A1, the cycle number of the durability load spectrum is calculated as follows:

[0054] n=T / T0=3311 / 2.75

[0055] T=K·A0·H=1.204·2.75·500

[0056] In the formula, A0 is the working time of the screw pump in one working profile of the equipment, 2.75 hours, H is the total working number required by the equipment, 1000 times (the working number required by one overhaul of the equipment); K is the equipment margin coefficient, which is 1.204 (referring to the 30-1 time truncation test scheme in GJB899A-2009 “Reliability identification and acceptance test”); T is the total running time of the screw pump, which is 3311 hours; T0 is the one-cycle time of the durability load spectrum, which is 2.75 hours; n is the cycle number of the durability load spectrum, which is 1204 times;

[0057] A2, the one-cycle spectrum curve of the durability load spectrum: the spectrum curve when the screw pump runs once is determined according to the equipment running, which is determined by the parameters such as the screw pump speed, outlet pressure and outlet flow. In order to shorten the durability test time, the spectrum curve is usually accelerated based on the “equal work principle”, that is, the screw pump power is improved to reduce the time to ensure that the screw pump does the same work. The screw pump of the present application is used for oil liquid circulation of the pump station, and the actual working pressure is constant at 2MPa, and the working time is 2.75 hours each time. The output flow of the screw pump is positively correlated with the speed, and in order to shorten the durability test, the screw pump speed is kept unchanged (constant speed operation), the screw pump pressure grade is improved to improve the screw pump power. The load spectrum of the present application is as follows: Figure 2As shown, the outlet pressure of the screw pump is adjusted to 2 MPa for 1 hour, 3 MPa for 0.5 hour, and 4 MPa for 0.5 hour, which is equivalent to 2 MPa for 1 hour, 2 MPa for 0.75 hour, and 2 MPa for 1 hour, i.e., 2 MPa for 2.75 hours.

[0058] B, test loading circuit design: the loading circuit is as shown in Figure 3 As shown, Figure 3 The reference numeral 2 is a test screw pump installation assembly for installing the test screw pump 7, and the driving device can change the rotation speed of the test screw pump according to the test working condition; Figure 3 The reference numeral 1 is an inlet pressure sensor for testing the inlet pressure of the test screw pump; the reference numeral 3 is an outlet pressure sensor for testing the outlet pressure of the test screw pump; and the reference numeral 4 is an outlet flowmeter for testing the outlet flow of the test screw pump, so as to realize the pressure and flow monitoring during the test process of the test screw pump and to calculate the displacement of the test screw pump according to GB / T 7936-2012 “Method for Determining the No-load Displacement of Hydraulic Pumps and Motors” to convert the volumetric efficiency of the test screw pump. Figure 3 The reference numeral 5 is a screw pump durability and performance test loading assembly, Figure 3 The reference numeral 6 is a proportional overflow valve added in the durability and performance test loading assembly, which can adjust the output pressure of the test screw pump to realize stepless adjustment of the durability load spectrum of the test screw pump, so as to realize the cyclic operation of the screw pump durability test load spectrum determined in step A, and also to satisfy the stepless adjustment and closed-loop control of the performance test load of the rated flow and volumetric efficiency of the test screw pump, so as to realize the test of the rated flow and volumetric efficiency parameters of the test screw pump.

[0059] C, monitoring parameters during the test process: the actual operation of the screw pump load spectrum during the screw pump durability test process is monitored, and there is a certain deviation between the oil temperature affected screw pump durability test spectrum and the theoretical load spectrum, but the deviation is not more than ±5% of the theoretical load spectrum (referring to GB / T11705-2009 “Test Method for Electric Three-screw Pumps for Marine Use” standard, considering the influence of oil temperature, the allowable error is enlarged by 2 times); the screw pump leakage is monitored during the screw pump durability test process, and no leakage is allowed.

[0060] D, screw pump durability test judgment criteria: the judgment criteria are as shown in Figure 4 The screw pump is operated within the deviation range (not more than ±5%) of the specified load spectrum, the operation reaches the corresponding time requirement, and the leakage during the whole test process; the output flow of the screw pump under the working pressure grade is determined before and after the durability test, and the change is not more than 3% (referring to JB / T7043-2006 “Axial Piston Pump” standard); and there is no obvious wear or deformation of the screw after the durability test.

[0061] To fully test the durability of the screw pump test, the following tests can also be appropriately increased: ① The pump body temperature is normal, generally not more than 90℃; ② No abnormal sound during operation; ③ The oil cleanliness does not exceed the use range of the screw pump; ④ The sealing element has no obvious deformation; ⑤ The pump body has no visible cracks.

[0062] The present application is characterized by low pressure and large flow under actual working conditions, and the working pressure is appropriately increased according to the "equal work principle", the stress of the key friction pair is increased, the friction is fully performed, the test speed is accelerated, the maximum pressure is up to 4MPa, the working pressure changes from 2MPa to 4MPa during the test, and the output is performed at a constant displacement of 500ml / r, a total of 500 complete load spectrum cycles, a single cycle working time is 2 hours, and the test time is 1000 hours. After the test, the screw pump is disassembled, the wear of the driving screw, the driven screw and the pump body is checked, and under the same pressure grade, speed and oil temperature, the pump flow is compared before and after the test, and the decrease is not more than 3% as the judgment basis.

[0063] Example 2:

[0064] The axial piston pump formed by the flow distribution disc in the hydraulic system of the underwater acoustic equipment is commonly used as a power source of the hydraulic system, and the axial piston pump is composed of a flow distribution disc, a cylinder body, a piston, a main shaft, a sliding shoe, a return disc, a return spring, an inclined disc, a variable mechanism and the like.

[0065] The working principle of the axial piston pump is as follows: the cylinder body and the piston form a sealed piston cavity, and are driven to rotate around the main shaft under the driving of the motor, and the sliding shoe is at the bottom of the piston, and is tightly attached to the inclined disc under the action of the return disc and the return spring, and the inclined disc has an inclination angle under the adjustment of the variable mechanism, so that the piston reciprocates relative to the cylinder body during rotation, the volume of the piston cavity changes periodically with the rotation of the main shaft, and the oil suction and oil discharge are performed under the separation of the flow distribution disc, the output pressure and flow are output, and the mechanical energy transmitted by the motor is converted into hydraulic energy of the hydraulic system. The key friction pairs include the flow distribution pair between the flow distribution disc and the cylinder body, the piston pair between the cylinder body and the piston, the ball hinge pair between the piston and the sliding shoe, and the sliding shoe pair between the sliding shoe and the inclined disc. The matching state of these key friction pairs has an important influence on the performance of the axial piston pump.

[0066] The present embodiment discloses a kind of piston pump durability test method for underwater acoustic equipment, which is as follows: Figure 5 The present embodiment discloses a kind of piston pump durability test method for underwater acoustic equipment, which is as follows:

[0067] 1. Determination of Load Spectrum and Cycle Count: Considering the actual operating conditions of the plunger pump, its rated working pressure is 20MPa, and the maximum pressure can reach 30MPa. The plunger pump mainly supplies pressurized oil under different pressure and flow rates. Therefore, the load spectrum design should take into account the working pressure profile of the plunger pump and alternating loads. The pressure change is a step change, and the load spectrum should be determined based on the "equal work principle." Figure 6 The test profile load of the plunger pump shown is based on three operating pressures of 3MPa, 20MPa, and 30MPa under normal operating conditions, combined with three flow rates corresponding to the maximum power: 530L / min, 405L / min, and 270L / min, at 1 / 3, 2 / 3, and 1 respectively. A standby condition at 30MPa pressure and 15L / min is also included. The alternating load pressure is a sinusoidal signal alternation (18MPa-30MPa, period of 120s, satisfying the formula P = 6*sin((π / 60)*t) + 24), with power ranging from 15-132kW. One complete sinusoidal pressure signal change period constitutes one cycle. Accelerated testing is not considered in this invention. Based on the actual operating time of the plunger pump and the selected margin coefficient, the total test duration is determined to be 1000 hours, one cycle of the load spectrum is 20 hours, and the number of load spectrum cycles is calculated to be 50.

[0068] T=K·A0·H=1.204×2.08×400=1001.73≈1000

[0069] n = T / T0 = 1000 / 20 = 50

[0070] In the formula,

[0071] T – Total operating time of the plunger pump, taken as 1000 hours;

[0072] A0—The equivalent working time of the plunger pump for each operation of the equipment, taken as 2.08 hours;

[0073] H – The required number of operations for the equipment, taken as 400;

[0074] K—Margin coefficient, taken as 1.204 (refer to the timed truncation test scheme 30-1 in GJB899A-2009 "Reliability Qualification and Acceptance Test");

[0075] n—Number of load spectrum cycles, 50;

[0076] T0 — Load spectrum cycle time, 20 hours;

[0077] 2. Hydraulic loading circuit design: In order to achieve Figure 6 The load spectrum shown is designed to include a hydraulic loading circuit with a piston pump, such as... Figure 7As shown, mainly includes motor 8, test plunger pump 9, electric proportional overflow valve 10, large flow proportional overflow valve 11, temperature sensor 12, pressure sensor 13 and flow meter 14. Among them, electric proportional overflow valve 10 is used for remote control test plunger pump pressure, adjusting the upper limit of test plunger pump output pressure, large flow proportional overflow valve 11 is used for controlling the loading pressure of durability test circuit. During the test, the set pressure of electric proportional overflow valve 10 is higher than the highest pressure of system loading. Specifically: the system changes the oil line resistance by setting proportional overflow valve in the output oil line, changes the pressure, achieves the purpose of loading test plunger pump. By changing the motor speed, the purpose of adjusting the flow of test plunger pump is achieved. The PLC-computer output signal is amplified by proportional amplifier to drive proportional overflow valve to realize pump load pressure control simulation, so as to realize: (1) meet the load pressure steady-state closed-loop control of durability test and performance test; (2) provide stepless adjustable steady-state, low-frequency triangular wave load force for static characteristic test; (3) provide load pressure, load according to data curve, have standard typical load curve, can define load curve, can realize data driven load curve. The main hydraulic control valve of load pressure control module is plug-in proportional overflow valve to realize load pressure control.

[0078] 3. Monitor parameters during the process and design monitoring software: by analyzing the failure mode of plunger pump, it is inferred that the abnormal performance after plunger pump failure is that the pump cannot start normally, the pump flow is insufficient, abnormal noise, working medium leakage, pump body temperature is too high, etc. Based on this, the main parameters to be monitored during the test process are determined, and the focus is on plunger pump leakage, abnormal noise, speed, output flow, suction pressure, output pressure, pump body temperature, medium temperature, oil cleanliness, etc. Figure 8 . Among them, the speed, output flow, suction pressure, output pressure and medium temperature are monitored in real time by designing software, and the data are saved and analyzed in real time, and the data sampling frequency is not less than 10 Hz; plunger pump leakage, abnormal noise, pump body temperature and oil cleanliness are checked and judged by periodic inspection, plunger pump leakage, abnormal noise and pump body temperature are checked every 3 hours, and oil cleanliness is sampled and detected before, during and after the test.

[0079] 4. Test: before starting the test, the test equipment should be checked, cleaned and tested to ensure that there is no fault before the test; during the test, according to Figure 6 Load spectrum, load the plunger pump, based on Figure 8 Parameter monitoring is carried out to ensure that the test meets the test requirements, there is no leakage and abnormal noise, the load meets the requirements, and the data recorded meets Figure 8The test time is included in the total duration of the durability test. After the test is completed, the performance of the plunger pump is tested first, and the performance of the plunger pump before and after the test is compared. In addition, the plunger pump needs to be disassembled and inspected to check the basic condition of the key friction parts of the plunger pump.

[0080] 5. Data comprehensive analysis and evaluation: The test data before the test, the software detection data during the test, the inspection data, the test data after the test, and the disassembly data of the plunger pump are comprehensively analyzed and evaluated to determine whether the plunger pump passes the durability test from the test process, the performance after the test, and the disassembly wear condition, such as Figure 9 The actual loading condition of the plunger pump during the test deviates from the set load spectrum by less than 5%, there is no medium leakage, the pump body temperature does not rise suddenly, there is no obvious abnormal sound during operation, the oil cleanliness meets the operation requirements of the plunger pump, the no-load displacement, constant-power pressure flow curve and efficiency characteristics meet the requirements; the control displacement, efficiency characteristics and constant-power pressure flow curve of the plunger pump after the test should meet the design requirements, and the output flow under the same working condition is reduced by less than 3%; the plunger pump is disassembled, and there is no obvious wear or deformation of the plunger pair, no obvious deformation of the sealing element, and no visible cracks in the pump body. If the above conditions are met, the plunger pump meets the user's usage requirements and passes the durability test, otherwise, optimization design is needed according to the actual situation.

[0081] Plunger pump failure judgment criteria: The main purpose of plunger pump durability test is to evaluate the durability of plunger pump in long-term operation, and to determine whether the plunger pump meets the user's usage requirements. Therefore, the plunger pump state during the plunger pump durability test, the performance decline after the durability test, and the plunger pump wear condition are comprehensively judged to determine whether the plunger pump passes the durability test and meets the user's usage requirements.

[0082] Failure judgment criteria during durability test: ① During the test, considering the influence of medium temperature and other factors, the actual operating condition of the plunger pump and the load spectrum will deviate to a certain extent, but the deviation from the set load spectrum should not exceed 5%; ② There is no medium leakage in the plunger pump; ③ The pump body temperature is normal, generally not more than 90℃; ④ There is no abnormal sound during operation; ⑤ The number of load spectrum cycles meets the set requirements; ⑥ The oil cleanliness is detected regularly and does not exceed the usage range of the plunger pump.

[0083] Performance decline failure judgment criteria for durability test: Combined with the analysis in step D and the usage function of the plunger pump, the performance of the plunger pump will decline to a certain extent during the durability test, mainly in volumetric efficiency. Therefore, the volumetric efficiency of the plunger pump should not decrease too much, that is, the output flow of the plunger pump under the same working condition should not decrease by more than 3%.

[0084] Durability test wear failure criteria: after the test, the plunger pump is disassembled and inspected, according to the failure mode, mainly to check the wear condition, the requirements are as follows: ① the plunger pair has no obvious wear or deformation; ② the sealing element has no obvious deformation; ③ the pump body has no visible cracks.

[0085] The performance decline of the axial plunger pump after long-term use mainly reflects in the key indicator of "volumetric efficiency". In the preparation of the axial plunger pump durability test method, the changes in the pressure and flow range of the axial plunger pump during operation are mainly considered, and the durability test of different pressure and displacement conditions is required. According to the "equal work principle", the actual working condition of the axial plunger pump is restored, and the alternating load is set to fully friction and wear the key friction pairs. The highest working pressure is 30 MPa, the maximum displacement is 355 mL / r, and the pressure and displacement are alternated during the test. A total of 50 complete load spectrum cycles are completed, and the single cycle working time is 20 hours. The test time is 1000 hours. After the test, the axial plunger pump needs to be disassembled and inspected for wear of the flow distribution plate, cylinder body, plunger, sliding shoe, swash plate, aging state of the return spring and action of the variable mechanism. Finally, a reliable conclusion is drawn on the durability of the axial plunger pump.

[0086] It can be understood that equivalent replacement or changes to the technical solutions and inventive concepts of the present application by those skilled in the art shall fall within the protection scope of the claims appended to the present application.

Claims

1. A durability testing method for a hydraulic pump used in underwater acoustic equipment, characterized in that: The steps include the following: Based on the hydraulic pump's working task profile and margin coefficient, formulate the hydraulic pump durability test load spectrum based on the "equal work principle"; based on the hydraulic pump durability test load spectrum, design the hydraulic pump's loading circuit for testing; and based on the durability test result judgment criteria, determine whether the hydraulic pump meets the user's requirements. The hydraulic pump is a piston pump, and the specific steps include: A. Based on the working task profile and alternating load of the plunger pump, formulate the plunger pump durability test load spectrum, and calculate the number of load spectrum cycles by combining the "equal work principle" and margin coefficient. The screw pump durability test load spectrum consists of the number of cycles and the spectrum curve of one cycle, thereby determining the test process parameters. In the formula, A0 is the working time of the plunger pump converted for each operation of the equipment, H is the number of operations required by the equipment; K is the margin coefficient; T is the total working time of the plunger pump; T0 is the cycle time of one load spectrum; n is the number of load spectrum cycles; "equal work principle" means that increasing the power of the plunger pump and reducing the time ensures the same work is done. B. Design the loading circuit based on the plunger pump function and load spectrum: Based on the plunger pump durability test load spectrum determined in step A, determine the maximum working flow rate, maximum working pressure, maximum speed, and hydraulic circuit loading and flow control method of the plunger pump circuit to ensure that the pressure and flow rate in the load spectrum can be achieved during the test; in the loading circuit, the pump head pressure is adjusted by a proportional relief valve and the output flow rate of the plunger pump is adjusted by a motor to achieve the design pressure and flow rate of the load spectrum; C. Analyze the failure mechanisms of piston pumps, including wear, fatigue, and seal aging, infer the types of abnormal phenomena in piston pumps, and determine the parameters that need to be monitored during the durability process of piston pumps. D. Test Procedure: Before the test, install, inspect, clean, and conduct trial operation to ensure no faults; during the test, operate according to the load spectrum, monitor parameters, and check regularly; during the test, conduct performance tests and check changes in no-load displacement, constant power pressure-flow curves, and efficiency characteristics; after the test, conduct performance tests and disassembly inspection. E. Based on the test results judgment criteria, analyze and determine whether the plunger pump meets the user's needs.

2. The durability testing method for hydraulic pumps used in underwater acoustic equipment according to claim 1, characterized in that: The load spectrum includes the working pressure, working flow rate, and profile working time of the plunger pump. During the load spectrum development process, the failure modes of the plunger pump are combined with the test acceleration parameters set according to user needs to accelerate the durability test.

3. The durability testing method for hydraulic pumps used in underwater acoustic equipment according to claim 2, characterized in that: The abnormal phenomena of the plunger pump include pump failure to start normally, insufficient pump flow, abnormal noise, leakage of working medium, and excessively high pump body temperature; the monitored parameters include leakage, speed, flow rate, pressure, pump body temperature, abnormal noise, medium temperature, and oil cleanliness.

4. The durability testing method for hydraulic pumps used in underwater acoustic equipment according to claim 3, characterized in that: Step E specifically includes: E1. Test status determination: no leakage, no abnormal pump body temperature, no abnormal noise, meets load spectrum requirements, cleanliness meets requirements, time meets requirements, and performance check meets requirements during the test; E2. Performance check: The no-load displacement, efficiency characteristics, and constant power pressure-flow curve meet the requirements, and the output flow of the plunger pump decreases by no more than 3%, with no oil leakage or seepage. E3. Parts Wear Inspection: After the test, the plunger pump is disassembled and inspected to check the wear condition. The requirements are as follows: the plunger assembly has no obvious wear or deformation, the seals have no obvious deformation, and the pump body has no visible cracks.

5. The durability testing method for hydraulic pumps used in underwater acoustic equipment according to claim 4, characterized in that: The criteria for judging the test results are based on a comprehensive analysis from three perspectives: data analysis during the test, performance of the plunger pump before, during and after the test, and disassembly of the plunger pump after the test, covering abnormal phenomena of the plunger pump.

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