Thermal Performance Analysis Of High Speed Hybrid Spindle And Design And Optimization Of Cooling System

High speed hybird built-in spindle is the key functional component of thehigh-grade CNC machine tools. Performance of electric spindle system directlyaffects the machining quality. Usually,an electric spindle system consists of spindle,hybird liquid bearing, the built-in motor and other components. The rotation of thespindle is driven by a built-in motor, and it is supported by liquid hybridbearings. When the spindle is rotating at high speed, friction between spindle andliquid create heat at the liquid sliding bearing.If the heat can not be conductedeffectively, high temperature will bring about thermal deformation of spindle andbearings, thus affecting the performance spindle system seriously.Much worsely, theelectric spindle system may not work properly. Therefore, it is necessary to studythermal properties of hybrid bearing in high-speed spindle and optimization of itsstructure. Based on those ideas, the main contents of this paper are as follows:Firstly, this papar calculates oil film characteristics of deep-shallowcavity liquid hybird bearing by solving the Navier-Stokes equation. Then the autherdiscusses the influence of various working parameters and structure parameters of thedeep-shallow cavity bearings on the bearing rigidity and temperature rise. Thestiffness and temperature distribution of the bearings with straight-cavity andturning-cavity are compared．Secondly,the paper studies the influence of the splitting effect of the spiral oilwedge on the bearing temperature rise.Through the calculation of oil filmcharacteristics, the paper summarizes influence of various structural parameters ofspiral oil wedge bearing on the performance of bearing rigidity and temperature rise;Thirdly, in order to optimize the structure of the hybird bearing, after theexperimental design and accuracy evaluation of agent model is given, the radial basisfunction model of temperature rise and the stiffness is established. The micromulti-objective genetic algorithm is used to optimize the bearing structure. After thetarget range is selected,the CFD model is to be solved in the given range to obtainaccurate target.