Optimal Design Of The Key Parameters To Rollin Mill Oil-film Bearing

As the main parts of heavy strip mill, the structure design of oil film bearing is crucial to the bearing capacity and service life. The structure parameters of oil film bearing include bearing diameter, breadth, clearance, lubricating oil, material type and thickness of bearing alloy, etc.. The aim to choose the structure of bearing is to increase the oil flow into the bearing clearance, which can take away the heat produced by high speed, enlarge the projected area (bearing internal diameter plus breadth) and increase wedge gradient of convergent region, thus the bearing capacity can be increased.In this thesis, the finite element analysis software ANSYS WOEKBENCH and CFX was used to obtain the distribution of oil film pressure and temperature, the deformation and stress of bushing, etc.. The bidirectional fluid-to-solid coupling method was applied to find out the best relative clearance and thickness of bushing alloy, which can provide theoretical data to bearing structure optimization.The research contents are briefly as follows:1. The deepening research of oil film bearing lubrication theory. With a series of hypothesis, the mathematic model of oil film pressure field and temperature distribution was established. The simplified N-S control equation and boundary conditions were gotten. The research of lubrication theoretical is base of bearing's structure design and compute.2. According to the theoretical lubrication calculation results and empirical values of oil film bearing, the certain initial parameter of oil film bearing was determined to design the whole structure of bearing.3. By using the software of finite element analysis to analyze the bearing with one-way fluid-structure coupled method, we get the best thickness of bush alloy. Firstly, by using the software of finite element analysis CFX, we get the distribution of oil film pressure on a certain clearance; secondly, by using the software of finite analysis WORKBENCH, we get the distribution of bush stress; finally, by analyzing the result, we get the best thickness of bush alloy.4. The software of finite element analysis CFX and WORKBENCH with bidirectional fluid-to-solid coupling method was used to get the best relative clearance. Firstly, under the same rolling loadcase, the relationship between eccentricity ratio and load-carrying capacity, the maximum pressure of oil film, film temperature at different relative clearances were calculated; secondly, with the linear fitting, the relative ship between clearance and load-carrying capacity, maximum pressure of oil film, film temperature at the same load-carrying capacity were also obtained. Finally, the best relative clearance with optimal design method at the same loadcase was got.5. According to the similarity theory, the load-carrying capacity of the bearing and the temperatures were tested at laboratory.