External return mechanism is a mechanical structure applied to axial piston pumps.To study its lubrication characteristics,the Reynolds equation applied to an external return spherical hinge pair was deduced based on ...External return mechanism is a mechanical structure applied to axial piston pumps.To study its lubrication characteristics,the Reynolds equation applied to an external return spherical hinge pair was deduced based on the vector equation of relative-motion velocity of the external return spherical hinge pair under the influence of external swash plate inclination and offset distance.The results show that the total friction,axial leakage flow,and maximum value of the maximum oil-film pressure increase with increasing pump-shaft speed and decrease with increasing offset distance in one working cycle when the external-swash-plate inclination is constant.However,the varying offset distance has little effect on the axial leakage flow.The maximum value of the maximum oil-film pressure decreases with increasing external-swash-plate inclination and the total leakage flow increases with increasing external-swash-plate inclination in one working cycle when the offset distance is constant.It can be seen that the abovementioned parameters are important factors that affect the lubrication characteristics of external return spherical hinge pairs.Therefore,the complex effects of different coupling parameters should be comprehensively considered in the design of the external return mechanism.展开更多
This paper takes No.52 return uphill roadway of Yangquhe coal mine as a research project. Based on the research, especially its geological condition, indoor experiments, numerical simulation and theoretical analysis w...This paper takes No.52 return uphill roadway of Yangquhe coal mine as a research project. Based on the research, especially its geological condition, indoor experiments, numerical simulation and theoretical analysis were employed to determine the difficult coefficients of Yangquhe project. By using these means,the difficult coefficients of the deep rock engineering were determined. From a study of the effects of crustal stress and the roof mechanism on roadway stability, the transformation mechanism in Yangquhe coal mine has been determined. As a result of this research, the interactive support technology of prestressed cable mesh was developed and the technology tested in mining engineering, which proved to be feasible.展开更多
The development of pension finance is of great significance to China. first of all, the development of pension finance is conducive to improving China＇s multi-level and multi-pillar pension system, promote the sustai...The development of pension finance is of great significance to China. first of all, the development of pension finance is conducive to improving China＇s multi-level and multi-pillar pension system, promote the sustainable development of the social security system; secondly, the development of pension finance will create a new ＂blue ocean＂ in the financial markets, which is conducive to the improvement of China＇s financial system and capital market;finally, the development of pension finance will help supply-side reforms,which is conducive to the healthy development of the national economy of china. But now there are many difficulties： first, the top-design of China＇s social security system is not perfect; secondly, the current development model of pension finance in China is unclear, the return on investment mechanism is not perfect, the attractiveness of these projects needs to be improved; finally, under the background of Interact finance, mixed supervision is imminent. Therefore, under the new economic conditions must be structured from the supply side of the reform, the development of pension funds to seek the right ideas.展开更多
基金Project(GXXT-2019-048)supported by the University Synergy Innovation Program of Anhui Province,ChinaProject(51575002)supported by the National Natural Science Foundation of ChinaProject(gxbj ZD11)supported by the Top-Notch Talent Program of University(Profession)in Anhui Province,China。
文摘External return mechanism is a mechanical structure applied to axial piston pumps.To study its lubrication characteristics,the Reynolds equation applied to an external return spherical hinge pair was deduced based on the vector equation of relative-motion velocity of the external return spherical hinge pair under the influence of external swash plate inclination and offset distance.The results show that the total friction,axial leakage flow,and maximum value of the maximum oil-film pressure increase with increasing pump-shaft speed and decrease with increasing offset distance in one working cycle when the external-swash-plate inclination is constant.However,the varying offset distance has little effect on the axial leakage flow.The maximum value of the maximum oil-film pressure decreases with increasing external-swash-plate inclination and the total leakage flow increases with increasing external-swash-plate inclination in one working cycle when the offset distance is constant.It can be seen that the abovementioned parameters are important factors that affect the lubrication characteristics of external return spherical hinge pairs.Therefore,the complex effects of different coupling parameters should be comprehensively considered in the design of the external return mechanism.
文摘This paper takes No.52 return uphill roadway of Yangquhe coal mine as a research project. Based on the research, especially its geological condition, indoor experiments, numerical simulation and theoretical analysis were employed to determine the difficult coefficients of Yangquhe project. By using these means,the difficult coefficients of the deep rock engineering were determined. From a study of the effects of crustal stress and the roof mechanism on roadway stability, the transformation mechanism in Yangquhe coal mine has been determined. As a result of this research, the interactive support technology of prestressed cable mesh was developed and the technology tested in mining engineering, which proved to be feasible.
文摘The development of pension finance is of great significance to China. first of all, the development of pension finance is conducive to improving China＇s multi-level and multi-pillar pension system, promote the sustainable development of the social security system; secondly, the development of pension finance will create a new ＂blue ocean＂ in the financial markets, which is conducive to the improvement of China＇s financial system and capital market;finally, the development of pension finance will help supply-side reforms,which is conducive to the healthy development of the national economy of china. But now there are many difficulties： first, the top-design of China＇s social security system is not perfect; secondly, the current development model of pension finance in China is unclear, the return on investment mechanism is not perfect, the attractiveness of these projects needs to be improved; finally, under the background of Interact finance, mixed supervision is imminent. Therefore, under the new economic conditions must be structured from the supply side of the reform, the development of pension funds to seek the right ideas.
