Research On Stability Analysis And Measurement And Control Technology Of Ultra-precision High-Speed Dynamic And Static Pressure Gas Bearing

As the core component of the machine tool,the high-speed spindle is one of the main factors that restrict the improvement of machining precision.In order to improve the stability of high-speed spindle,this paper combines the advantages of high speed and large load of gas bearing with the high controllability of active magnetic bearing,and designs a gas dynamic and static pressure hybrid lubrication bearing and radial active magnetic bearing as support.The ultra-precision high-speed dynamic and static-pressure gas-magnetic main shaft structure of the bearing is studied and analyzed by means of theoretical modeling and simulation verification.The structure of the gas dynamic and static pressure hybrid lubrication bearing and the radial active magnetic bearing and the stability of the ultra-precision high-speed dynamic and static pressure magnetic spindle are studied..According to the gas state,continuity and dynamic equations,the Reynolds equation of gas bearing suitable for general conditions is derived.The pressure distribution of the gas film flow field inside the gas dynamic and static pressure hybrid lubrication bearing is simulated by Fluent,and the throttle aperture and speed are obtained.The relationship between the main structural parameters such as gas supply pressure and gas average gap and the static properties such as bearing capacity and stiffness,optimize the design of gas dynamic and static pressure hybrid lubrication bearings,and determine the optimal structural parameters.The mathematical model of the suspension force of the radial active magnetic suspension bearing is established.The vibration of the rotor is controlled by PID control method.The simulation of the PID control method is carried out by Matlab simulink simulation software to obtain the vibration range of the rotor axis.The radial active magnetic bearing structure is designed.The magnetic flux density and magnetic field force of the radial active magnetic bearing are calculated by simulation.The detection device and method of the ultra-precision high-speed dynamic and static pressure magnetic spindle are studied.The differential equation of elastic rotor motion and the differential equation of rigid rotor motion are established for the motion of super-precision high-speed dynamic and static-pressure magnetic spindle.The eddy state response of super-precision high-speed dynamic and static-pressure gas-magnetic main shaft rigid rotor and elastic rotor,super-precision high-speed dynamic static pressure gas is established by Matlab.The control current of the rigid rotor of the magnetic spindle and the centroid motion of the elastic rotor disc,and the rigid rotor and elastic rotor system cof the super-precision high-speed dynamic and static-pressure gas-magnetic spindle arc studied and analyzed.The Lyapanow motion stability is judged by the differential equation of motion of the elastic rotor。...