Structure Optimization Design And System Stability Analysis Of Super-High Speed Air Spindle

With the miniaturization of electronic components and various electrical functions,PCB board integration is also getting higher and higher,PCB board is also more and more dense holes.In order to improve the drilling efficiency of the dense hole and improve the drilling quality of the micropores,the drilling of the PCB micropores is often drilled with ultrahigh-speed hydrostatic spindle.Ultra-high-speed spindle is the biggest feature of the gas as a lubricating medium to achieve a pollution-free,zero friction,high precision rotary processing objectives,gas lubrication has brought significant advantages at the same time also has its own shortcomings,To avoid the compression caused by high-speed spindle in the work of the operation will appear unstable phenomenon.In order to solve the problem of structural and stability of the spindle system,the structure of the radial bearing and the axial thrust bearing are optimized,and motorized spindle system improve and enhance in the form of supporting structure.The vibration and vortex Dynamic stability of the two dynamic stability problems and the actual operation of the process of dynamic response to the problem of research and analysis,the main content is composed of the following sections:Firstly,using the fluid mechanics to derive the Reynolds equation of the gas lubrication,the Reynolds number of the fluid in the hydrostatic bearing is calculated to determine the fluid state to be analyzed.The pressure cloud obtained from the fluid analysis of the bearing can be used to analyze the bearing The bearing capacity and stiffness of the film in the gap are determined by the numerical analysis function of the MATLAB software.The relationship between the bearing parameters and the bearing capacity and the stiffness of the bearing is obtained by combining the required lubrication equation.The size of the structure to achieve the optimal design of the bearing.Secondly,the radial stiffness of the spindle system is deduced by analyzing the radial rigidity of the spindle system.According to the laws of the equations of general form characteristic is proposed to add support and the concrete is placed.For the proposed hypothesis,based on the analysis of the results of optimization have been carried out to verify the best form of supporting structure.Thirdly,the motorized spindle system stability problem is divided into two parts of the dynamic and static study.One of the static stability problem is the air hammer vibration phenomenon,according to the stability of the gas bearing balance equation is derived,using the MATLAB software one by one the orifice diameter,gas pressure,gas cavity radius of influence of vibration of air hammer has made the analysis and research;In view of the dynamic stability of the vortex instability phenomenon,is based on gas bearing damping force formula for vortex instability and spindle diameter of axle rotational speed two relations were analyzed,using regular graph vortex of motorized spindle speed and diameter of axle rotational speed with the changing rule of the damping coefficient was summarized.Finally,using modal analysis to the main shaft natural frequency and the natural speed calculated.Then,the response of the natural frequency is analyzed and analyzed.The frequency response curve is used to analyze the frequency domain of the dynamic response of the spindle system,and the resonance phenomenon is greatly reduced.