Stability Analysis of a Ferrofluid Hydrodynamic Journal Bearing System with Halbach Array Magnetic

• Main Authors: Tang-Lun, Change, 張堂倫
• Other Authors: Yi-Hua,Fan
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/cu34qb

碩士 === 中原大學 === 機械工程研究所 === 103 === Nowadays,the fluid-lubricated bearing applying in the rotating machines are very widespread. However some instability phenomenas ,such as oil whip and oil whirl, will appear when the fluid-lubricated bearing is working. These phenomenas will make bearing vibrating and decrease life of machine. Against to solve this problem, the research propose a solution to optimization the instability phenomenas. We use ferrofluid replace used lubrication,and set Halbach array magnetic field to change ferrofluid characteristic to increase the frequencies of fluid-induced self-excited vibrations. So that the rotor system can prevent working in resonance frequencies. First, this research will build a fluid-dynamic bearing rotor test platform. Using ferrofluid as lubrication ,and set a general annular array magnetic and a Halbach array magnetic outside. Second, through observed different magnetic directions effect on oil whip and oil whirl. Finally, we can found the oil whip and oil whirl appear frequencies obviously increase by full spectrum cascade plots with Halbach array magnetic. The speed of fluid-induced self-excited vibrations is increased from 2940rpm to 4140rpm.