Investigation Of The Micro Self-excited Vibration Characteristics In Hydrostatic Thrust Bearing

Hydrostatic thrust bearing is widely used in the field of precision manufacturing and measurement because of its small wear, high precision, no pollution, low cost and many other advantages. Micro self-excited vibration (referred to as ’micro-vibration’) is found happening when hydrostatic thrust bearing works. The micro-vibration can’t be avoided because it’s caused by airflow in hydrostatic thrust bearing. With bad influence in hydrostatic thrust bearings’ stability, the micro-vibration is a important indicator for measuring hydrostatic thrust bearings’ performance.Micro self-excited vibration is the main part of this paper, the research has important theoretical and realistic significance in improving motion positioning performance of ultra precision system.Research content is as following:1) Two-dimensional Large Eddy Simulation (LES) is used to compare the gas flow field characteristics of hydrostatic thrust bearing with different structure. The area-weighted-average pressure on gas film is monitored and the gas pressure fluctuation variance and peak-peak value is investigated.2) The differential equation of single degree freedom vibration system is solved to turn pressure fluctuation into vibration displacement and the vibration amplitude of micro vibration is predicted.3) A monitoring and controlling software for hydrostatic thrust bearing performance detection device, based on LabVIEW, is designed.4) Experiment is done to measure vibration acceleration, double integral is used to turn the vibration acceleration into vibration displacement and the vibration displacement from experiment is compared with that from simulation.