| Journal bearing is an important part of mechanical equipment,which has many advantages,such as high bearing capacity,stable operation,anti-shaking and so on.As mechanical equipment is moving towards to high speed,high power,high automation direction,the bearing working conditions have become more severe,which put forward higher requirements on the lubrication of journal bearing.Oil-gas lubrication technology is one of the most advanced lubrication methods in the world,which has many advantages such as low oil consumption,high efficiency,good heat dissipation,and accurate control of oil quantity.At present,the research on oil-gas lubrication in journal bearings has made great breakthrough.Usually,a flow channel is set up in the journal bearing,and the lubricating oil is sprayed into the flow channel by the compressed air.Lubricating oil distribution in the flow channel influences the lubrication property directly,thereby affecting the quantity of heat production of bearing.If the distribution of lubricating oil can be improved and lubrication property can be enhanced,the heat production rate is less than the heat dissipation rate.Then the bearing temperature will not rise.Therefore,the influence of inlet structure of journal bearing on the distribution of lubricating oil will be researched through theoretical analysis,numerical simulation and experimental verification.Besides,the influence of gas pressure and other parameters on the distribution of oil film on the shaft wall is researched,too.The main contents of this paper are as follows:(1)Firstly,the current development of oil-gas lubrication and journal bearings are summarized.And the heating problem of radial journal bearing is analyzed.Then,the application of oil-air lubrication technology in journal bearing is discussed.Finally,mathematical model and physical model are established when simulating oil-gas injection process with Fluent software.(2)Through the numerical calculation method to simulate the oil-gas injection process,the distribution of droplets in the process of oil-gas injection is analyzed,and the distribution of the lubricating oil droplets in different flow channels is studied,including the injection area,droplet size and distribution.Some basic principles are provided for the design of the flow channel comparative analysis.(3)Through the method of numerical calculation to simulate the oil-gas injection process,the forming process of the oil film on shaft neck wall is researched in the flow channel.And the influence of gas pressure and other parameters on the distribution of oil film on the shaft wall is also researched,including film shape,film thickness,film mass and droplet diameter.It is of great significance to improve the distribution of oil film on the wall of the Journal bearings.(4)The oil-gas lubrication system is built.The temperature rise experiments of the different structure journal bearings are carried out on the journal bearing experiment table.The feasibility of the optimization of the structure of journal bearings is proved by experimental results. |
PDF Full Text Request