Dynamic Characteristics Analysis And Structural Optimization Of Journal Bearing And Rotor System

Slide bearing has been widely used in modern rotating machinery as a rotary support element because of its advantages, such as strong bearing capacity, stable and reliable operation, and low noise. Good performance of sliding bearing lubrication plays a vital role on the security and reliability of rotating machinery. With the high-speed, light developing direction of modern rotating machinery, it is increasingly important in static characteristics and dynamic characteristics analysis and optimized design. This article focuses on the numerical analysis of the lubrication state and dynamic characteristics of sliding bearing, and the intelligent algorithm is used to optimize sliding bearing. The main work and results are summarized as follows:1. The article analysis sliding bearing lubrication. The article analysis the hydrodynamic lubrication theory of the sliding bearing, and derives two dimensional Reynolds equation which is suitable for sliding bearing. Differential principle and Matlab software are used for solving Reynolds equation to get the numerical solution, and analyze how sliding bearing structural parameters affect its lubricating properties. The results show that pressure film will increase following with the eccentricity or wide-diameter ratio increasing.2. The dynamic characteristics of the rotor-bearing system are studied. By analyzing the rotor-bearing system working principle and instability mechanism, and studying rotor-bearing system dynamic characteristics at the disturbance, it comes to unsteady Reynolds equation applying to such situations. Unsteady Reynolds equation is solved to obtain the stiffness and damping coefficients using pressure perturbation method, and analyzes how the bearing structural parameters affect these coefficients. Instable speed and instability of the single symmetric elastic rotor are calculated and analyzed, and the effect of structural parameters on the instable speed and stability are studied.3. By using Matlab genetic algorithm toolbox, the performances of hydrodynamic sliding bearing lubrication are optimized from carrying capacity coefficient, friction factor and heat, which can obtain multi-objective function expression. Finally, the optimized results are obtained by solving the multi-objective function. Compared the optimization results with the original data, the performance parameters are all raised.