Study On Bearing Characteristics Of The Heavy Hydrostatic Bearing With Variable Viscosity

With the development of modern industry, rotating machinery tend to be more highly efficient, high-speed, high precision and high power at present, furthermore, rotating machinery needs high precision, low power consumption, high stability of the bearings as the system supporting parts. Accordingly, as the study of hydrodynamic lubrication bearings, it is founded that the lubrication property of the hydrostatic bearings have a great impact on the service life and reliability of hydrostatic bearings, and its advantages or disadvantages of lubrication performance has a direct influence on the reliability, service life and economic indicators of the entire machine tool operation. However, Studying on the lubrication performance under considering the variable viscosity and centrifugal force is still a weak link.First, the current situation of the researching on hydrostatic bearing at home and abroad is summaried through reading lots of related papers and investigating in actual plant. Then, the lubrication mechanism of heavy hydrostatic bearing is analyzed.Then, aiming at large multi-oil pad hydrostatic bearing, the viscosity-temperature equation of lubricating oil, the control equation in rotating coordinate system, the flow rate formula, the temperature formula, the pressure formula of gaps fluid are derived, the three-dimensional flow mathematical model of gaps fluid is established under different working conditions.After that, according to the actual working condition in the factory, the critical inlet flow capacity and the critical rotating speed of the hydrostatic bearing gap fluid from the laminar flow to the turbulent flow are calculated, and simulated by the numerical simulation method, the reliability of the rusult is verified.Finally, the flow field, the pressure field and the temperature field of gaps fluid for heavy hydrostatic bearing are numerical simulated by using the finite element and finite volume method, based on Computational Fluid Dynamics (CFD) principles, which comparative analysis to the theoretical calculations, the results is in good agreement.Through the above analysis and research, this thesis reveals the flow law of the hydrostatic bearing oil film, finds two main parameters of affecting hydrostatic bearing temperature rise, discusses affect the laws of two main parameters through a series of numerical simulation of gaps fluid. This study provides theoretical calculation method for the design of such bearing, provides a theoretical basis for researching on the variable viscosity fluid characteristics, provides a theoretical evidence for designing rational structure and excellent performance of the hydrostatic bearing.