Research On Performance Evalution Test System Of Hydraulic Filter Under Cyclic Flow Condition

At present, the filtration performance evalution test of the hydraulic filter is under constant flow condition, but in most of the hydraulic system, the flow rate of oil is often accompanied by fluctuating. Therefore, it is meaningful to propose performance evaluate method of the filter under cyclic flow condition.In 2005, ISO proposed the draft of the test standard for the filtration performance of the hydraulic filter under cyclic flow condition. But the method to realize the cyclic flow condition in the draft should be improved. By depth analysis, the proposed method is found that has two problems:the flow waveform is difficult to achieve and the weight contamination concentration of the oil in the test tank is more than the predetermined value.For further quantitatively analysis the above problems, software AMESim is used to simulate the change of the flow, the weight contamination concentration of the oil in the test tank is calculated. The simulation results show that, with the constant rising of the filter differential pressure, the flow waveform that through the filter is gradually deviated from the predetermined value, the flow waveform can not be achieved. The calculation results show that the weight contamination concentration of the oil tank will be seriously overweight predetermined value when the test is finished.By summarizing the shortcomings of the draft, the solution to the problem of the weight contamination concentration of the oil in the test tank exceed the standard is put forward. In addition, by summarizing the control method of the flow, three schemes are designed to realize the predetermined cyclic flow waveform. In order to further verify the feasibility and compare the pros and cons of different schemes, the software AMESim is used to build a filter model with a certain pressure drop-flow rate and time-pressure difference characteristics, then the hydraulic system model of the volume effect, friction effect and oil compressibility of the pipeline under different schemes are completed. The conclusion that the flow waveform of pump control scheme is better is getted. By taking into account the economic applicability, flow waveform characteristics and controlling the degree of difficulty, the pump control scheme should be the optimal scheme of cyclic flow waveform.Based on pump control scheme, the design of the main parts of the filter performance evaluation test bench and the calculation and selection of the related components are completed. The design of this paper provides a reference for the construction of the test bench for the performance evaluation of the filter under cyclic flow condition.