The Design And Characteristics Of The High-speed Spindle Pre-tightening Mechanism Of The Machine Tool

The processing level of the machine tool directly affects the overall level of manufacturing industry in our country,so the demand for high speed and high precision machine tool is becoming more and more urgent in the current trend.As the core component of the machine tool,the performance of the machine is directly related to the effective work of the machine tool.Preload technology of spindle is one of the important research direction of the spindle,the spindle can preload with spindle working conditions change in real time is adjusted to maintain an optimal working state is a key goal of the research field.Therefore,it is the precondition to realize high speed and high precision machine tool to keep the best dynamic characteristics in the full range of working conditions,so as to determine the optimum preload of the spindle and keep it in an adaptive control system.In this paper,the selection of the best preload of high speed angular contact ball bearing and the performance of the pre tightening mechanism are studied and analyzed:(1)Based on high speed angular contact ball bearing of statics and dynamics analysis,using Newton iterative method and using MATLAB software analyzes the high-speed angular contact ball bearing contact Angle,contact stress and moment of inertia.Based on Hertz contact theory and ANSYS simulation software analysis of rolling element and raceway contact properties.(2)According to the movement of high speed angular contact ball bearing,force,the relationship between the heat production,the simulation is established three-dimensional contours of bearing temperature distribution and the spindle speed,the pre-tightening force and rolling body temperature fitting curve;Based on the analysis of the main shaft pre-tightening force and axial displacement and the internal relation between the bearing temperature rise,on the basis of the appropriate pre-tightening force,curve of the spindle and the axial displacement of the corresponding graph.(3)With best pre-tightening force for the principle,put forward a new type of spindle preloaded from adjusting mechanism,the agency with laminated piezoelectric ceramic actuator as the driving source,flexible institution as a transfer institution.With force and displacement as parameters,the output of the piezoelectric ceramic in series with the output of the flexure hinge,finally got the compound output,to adjust to changes in the bearing temperature change of preload.Compared with constant pressure preload,obtained the good effect,the comparison of the agencies use adjustable preload and the bearing temperature change under the constant pressure preload comparison chart.