| Oil-air lubrication is a new lubrication technology that spreads the lubricating medium into small droplets and delivers them to the friction pairs accurately so that it can reduce the friction heat and extend the lifetime.It overcomes many disadvantages of traditional lubrication,and is widely used in the design of conventional parts lubrication with the characteristics of low oil consumption and zero emission.The influence of the oil-air lubrication flow behavior on the lubrication effect of point contact pair is mainly investigated.The main contents and conclusions are as follows:(1)Research on the numerical simulation method of oil-air lubrication flow field.The spatial model of oil-air lubrication point contact is established.According to the characteristics and flow properties of multiphase flow,VOF and RNG models are selected.The PISO equation is used to solve the governing equation iterative with appropriate physical parameters and boundary conditions setting.The simulation is carried out based on the certain model and method to observe the motion process of oil-air two phase flow and the surface oil-phase volume distribution.(2)By using the established space model and numerical simulation method,the effects of oil-air lubrication flow behavior on the lubrication of spatial flow field under different factors(oil supply,air supply velocity,jet azimuth and circumferential velocity)were investigated.The results show that oil-air lubrication process parameters(oil supply,air supply velocity and jet azimuth)can change the velocity distribution and pressure distribution of the spatial flow field and affect the shapes of oil film on the ball surface.The oil-air lubrication operating condition parameter(circumferential velocity)influences the uniformity of oil film by changing the distribution and adhesion of the oil-phase on the surface of the ball.(3)The point contact friction pair was used as the test object,oil-air lubrication test was conducted on the MFT-3000 friction and wear tester.While the effects of different parameters(oil supply,air supply velocity,jet azimuth and circumferential velocity)on the friction characteristics of point contact pairs were investigated with numerical simulation.The research shows that the reasonable lubrication parameters during the test are conducive to the compressed air to spray the fine oil droplets onto the surface of the friction pair.After the oil droplets collide,adhesion and spreading with the friction surface,an oil film layer is formed so that it can reduce the friction coefficient to achieve the effective lubrication of the friction pair. |
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