Research On The Influence Of Oil Film Stiffness Of Grinding Wheel Spindle Bearing Oil Film On Flutter And Vibration Reduction Control Method Of Centerless Grinder

Centerless grinder is a kind of machine tool that does not require clamping,high grinding efficiency,and compact structure when grinding workpieces.It is mainly used to complete the finishing and inspection evaluation of difficult-to-cut materials.It can grind cylinders,cones and cones in batches.The outer circle of the rotary forming workpiece belongs to the finishing equipment in the processing of the workpiece,and is widely used in various industries.In the process of use,sometimes there will be flutter of the centerless grinding machine,which will reduce the surface quality of the workpiece,damage the key parts of the grinding machine and produce noise pollution,which restricts the development process of the centerless grinding machine towards high speed,high efficiency and high precision.Therefore,the influence factors and The study of vibration reduction control methods has always been a difficult and hot spot in the field of machine tools.Aiming at the flutter of a centerless grinding machine,this paper analyzes the influencing factors,and designs a vibration reduction control system to suppress flutter by studying methods to maintain the stability of the oil film and measures to improve the stiffness of the oil film.First,based on the analysis of the principle of centerless grinding and the mechanism of flutter,a vibration dynamics model of the grinding mechanism of a centerless grinder is established to analyze the influence of the grinding wheel,the support and the adjusting wheel on the flutter.According to the grinding wheel spindle-oil film-bearing stiffness and damping calculation model,the difference method is used to calculate the oil film stiffness,and then the influence of the oil film stiffness on flutter is analyzed,which shows that increasing the oil film stiffness is an effective measure to suppress flutter.Secondly,establish a mathematical model of grinding wheel spindle-oil film-bearing vibration,solve the differential equations,and use the inherent parameters of the system to solve the oil film stiffness.Using MATLAB software programming,the limit values of the parameters are given through the Routh array,and Bode diagrams and step curves are drawn under different conditions of oil supply pressure,dynamic viscosity,diaphragm thickness and compressibility,revealing the stability of oil film vibration by different parameters The law of influence of nature provides value range and theoretical guidance for improving the rigidity of the system.Thirdly,based on the establishment of a three-dimensional oil film model,FLUENT is used to perform simulation calculations to solve the pressure field and temperature field distribution of the oil film under different working conditions,use the difference method to calculate the oil film stiffness,and analyze the influence of the working condition parameters on the oil film rigidity of the grinding wheel spindle bearing.The oil film stiffness function model of four-oil cavity equal area non-circumferential oil return radial hydrostatic bearing is deduced,and the function relationship between oil film stiffness and oil supply pressure,spindle speed,lubricating oil viscosity,film thickness,and spindle load is revealed.Finally,on the basis of the above theoretical research,the design criteria of the vibration reduction control system are proposed,and the hydraulic vibration reduction control system is designed.With the aid of AMESim software,the hydraulic control system model is established and the simulation analysis is carried out.The results show that the requirements of flutter suppression and damping control are met under different working conditions.