Analysis Of Dynamic Characteristics And Research On Stability Control Method Of Hydrostatic Gas Bearing

Gas bearing has the advantages of high speed,high precision,low friction and small limitation working range,so it has been widely used in aerospace,precision electronics,medical devices and other fields.As the core component of rotating machinery,the running stability of bearing-rotor system determines whether the equipment can work properly.When the gas bearing is running at high speed,the gas bearing-rotor system has strong nonlinear characteristics,in which the gas film force is an important factor leading to the instability of the bearing-rotor system.Therefore,it is necessary to study the dynamic characteristics of the bearing to improve the stability of the system.The main contents of this paper are as follows:(1)The structure of gas bearing and the basic principle of gas bearing are expounded,and the characteristics of spherical hydrostatic gas bearing are introduced.The mechanism of gas film instability of bearing-rotor system is analyzed,and the method of system stability analysis based on rotor vibration spectrum analysis is described.In this paper,the calculation method of identifying the dynamic characteristic coefficient of bearing gas film by using rotor vibration data is studied,and the Matlab program is compiled to calculate the transient dynamic characteristic coefficient.(2)Set up the test-bed of gas bearing-rotor system,select the appropriate test equipment to carry on the transient dynamic characteristic test and analysis experiment,The processing and transformation methods of vibration data needed in the process of identification of dynamic characteristic coefficients of gas bearing are studied.(3)The stability of the hydrostatic gas bearing is analyzed by the method of atlas analysis,and the vibration characteristics of the rotor during the development and change of the stability of the system are obtained.The eccentricity of rotor vibration and the transient dynamic characteristic coefficients of bearing are calculated,and the transient relationship between dynamic characteristic coefficient and eccentricity during the change of stability state during the operation of bearing-rotor system is analyzed.The influence of eccentricity,rotational speed and gas supply pressure on the dynamic characteristic coefficients of bearing is studied.(4)The stability control principle of the bearing-rotor system is studied.The stability control method of the bearing-rotor system is proposed to optimize the dynamic characteristics of the bearing based on the stability control principle and frequency modulation coupling technology to optimize the dynamic characteristics of the bearing.The experimental study on the operation stability control of the hydrostatic gas bearing is carried out to verify the effectiveness of the stability control method.