Lubrication Performance Study Of Composite Water-lubricated Bearing With Elasitc Deformation Taking Into Consideration

With gradual improvement of people’s awareness of environmental protection, water lubricated bearings with water as its working medium has attracted more and more attention of experts and scholars. Water lubrication replacing oil and grease lubrication, not only can save a lot of fuel and valuable non-ferrous metals and other strategic resources, but also can avoid pollution to water resources fundamentally. Now water lubricated bearing has been used in many occasion such as ship, turbine pumps, mining machinery, food applications and other equipments. Water lubricated bearing has a broad application prospects. On the one hand, due to the low viscosity of water, water film thickness is much smaller than that of oil under hydrodynamic lubrication. On the other hand, water-lubricated bearing materials are mainly non-metallic materials, generally with low modulus of elasticity such as the popular polymer composites. The bearing generates deformations when it is subjected to external loads, especially heavy loads and the minimum thickness of water film is the same order of magnitude as that of the elastic deformation. Therefore, the effect of the deformation cannot be ignored when studying the lubrication performance of water-lubricated bearing.Based on CFD software ANSYS CFX, 3D fluid-structure coupling models of water-lubricated bearings were solved. The influence of material parameters of the bearing such as elastic modulus, Poisson’s ratio, operating conditions such as shaft rotation speed, eccentricity of shaft, and structural parameters such as aspect ratio, clearance, bearing thickness on lubrication performance of water-lubricated journal bearing was studied. The lubrication performance includes water film pressure distribution, the highest pressure of water film, loading capacity and friction coefficient of bearing. Then, comparative analysis of the elastic deformation was obtained. And the situation where the bearing deformation has a greater impact on the lubrication performance of water-lubricated journal bearing was found.Finally, the material properties of bearing sample made of polymer composite materials were obtained through experiment and this provide a basis for the bearing design. In the process of the bearing design, fluid-solid coupling method was used to design the bearing for the frequently used operating conditions with bearing elastic deformation taken into consideration. Finally, a sample bearing was made through thermoset molding method by the studying group and then experiment was conduct to study its lubrication performance. The results show that the bearing exhibits a good lubrication performance under hydrodynamic lubrication.