TEHD Analysis Of Tilting Pad Thrust Bearing

Tilting pad thrust bearings are extensively used in power stations, steel machinery, and other large mechanical equipments. As the key component, the lubrication function of thrust bearing significantly affects the performance of machine. With the rapid development of modern industry, the operating speed and load of machine become much larger, and thrust bearings with higher performance are needed urgently.In 1990, Jun Zhu has investigated a number of thrust bearings, which were employed in hydro-generators of hydropower station. He found that the accidents of hydro-generators which are caused by the failure of bearings is 55-70% of the total accidents. Therefore, it is urgent to improve the performance of thrust bearing.Chapter 1 described the significance of TEHD analysis of thrust bearing, and reviewed research progresses of thrust bearing about hydrodynamic lubrication, elastohydrodynamic lubrication and experimental investigations, and briefly depicts overall structure, supporting structure, bearing material, and failure mode, and finally presents the work which will be done in this thesis.Chapter 2 established the TEHD model of tilting pad thrust bearing, which contains Reynolds equation, the viscosity-temperature and density-temperature characteristics of the lubricants, film thickness equation, energy equation, heat conduction equation, elastic deformation equation, and their boundary conditions.Chapter 3 presented dimensionless, discretization, solution method and solving process of above equations. The effects of different loads, rotational speeds, oil types and pad face materials on the performance were studied with THD theory.Chapter 4 analyzed the effects of inlet ramps on THD of tilting pad thrust bearing. Three types of inlet ramps and four different depths of linear ramp were studied.Chapter 5 calculated the lubrication performance of tilting pad thrust bearing in terms of TEHD, and compared with the results of THD model. The effects of different loads, rotational speeds and oil types on the performance were studied.Chapter 6 analyzed effects of misalignment of the shaft on TEHD of tilting pad thrust bearings.The last chapter summarized the present work in this thesis and put forward other important issues that need to be studied on in the next step of scientific research.