Research On Rapid Detection Technology Of Oil Supply Rate Of Shafting Core Valve For Space Applications

Passive micro-lubrication technology is a key form of micro-lubrication for space shaft systems.Adequate supply of lubricating oil is one of the key factors to ensure the stable operation of space shaft systems.The oil supply performance of the oil reservoir core valve directly affects the lubrication effect of the shaft system components,which in turn affects the lubrication performance,life and reliability of each component.At present,there is a lack of effective pre-testing technology for the oil supply rate of the shafting core valve at the component level.This paper proposes an equivalent method for rapid inspection of the oil supply rate of shafting core valve for the service conditions and technical requirements of space shafting lubrication.The gas permeability testing technology and engineering device of shafting core valve are developed and tested and functionally verified.The main contents are as follows:(1)Scanning electron microscopy and mercury piezometer were used to microscopically characterize the porous polyimide material for the shafting core valve.The results show that the porous polyimide cross-section is distributed with submicron-sized polyimide particles,and there are micro-pore channels distributed between the particles.The equivalent diameters were mainly distributed in the range of 0.1 ～ 1 μm.The measured porosity of the mercury piezometer is close to the nominal porosity,and the measured porosity is slightly larger than the nominal porosity.(2)Numerical simulation was used to establish a model of the internal micro-pore channel of the shafting core valve,and the seepage process of air and lubricant in the micro-pore channel was analyzed and studied.The results show that the flow patterns of air and lubricating oil in the micro-porous channel under certain pressure are basically the same.In this theoretical background,an equivalent method of using air instead of aerospace lubricant is proposed to achieve rapid detection of the oil supply rate of the shafting porous material core valve.(3)A gas permeability testing device for shafting core valve was developed.The results show that it is feasible to use air instead of lubricating oil to perform equivalent testing of the oil supply rate of shafting core valve.The time required to test the gas permeability of a single shafting core valve is less than 5 min.The gas permeability detection error of the device is less than 0.5%,which can meet the practical engineering needs of rapid oil supply rate detection of space shafting core valve.(4)The gas permeability testing device was used to conduct a batch testing of gas permeability of shafting core valve with different nominal porosity.The test results of the shafting core valve were obtained under different gas supply pressure,different gas supply time and repeatable loading.The relationship curve between oil supply rate and gas permeability was established by combining the measured oil supply rate data of the shafting core valve.The results show that the prediction error of oil supply rate is less than 6.0%,and the rapid detection method is expected to be the engineering technology for the pre-screening of oil supply rate of shafting core valve.