FSI Numerical Simulation And Experimental Research On Thermal Field Of Heavy Vertical Lathe Rotary-Table

Heavy CNC lathe is being used as the key processing equipment in heavy manufacturing,especially for the part which with large diameter.Turnery process of vertical lathe mainly depends on its rotary-table;the rotary-table is composed by workbench,base and lubricant film between them,as well as driving device.Accompanied with the development of high velocity cutting technology,a higher spindle velocity is required,but theoretical design and processing level of large parts at domestic can't meet the requirement,which causes uneven thickness between friction pairs,so there is a grave thermal load when the velocity is high.Simultaneously,thermal load produced by heat dissipation enhancing of workbench and base would cause thermal deformation which could impacts a serious risks on lubrication failure,even more,it maybe drive the actual model deviated from the theoretical design.So that,to study the thermal field and impact factor weights of lathe rotary-table,to reveal the thermal effect of hydrostatic bearing,regularity of heat conduction of workbench and base,heat dissipation and air flow field changing is the key to solve series of the situation.On the basis of summarizing the research on the rotary-table at domestic and abroad,including thermal load influence on hydrostatic bearing,the regularity of heat conduction and heat dissipation,and fluid-solid interaction(FSI)method,rotary-table of vertical lathe with hydrostatic bearing is analysed.Through the theoretical research,numerical simulation and experiment on composite thermal field of heavy vertical lathe rotary-table,the influence of thermal effect and impact factor,regularity of heat conduction and heat dissipation of lathe rotary-table is revealed,include the following aspects:Based on the research on heat conduction mechanism of rotary-table,the original heat conduction structure is simplified as composite heat conduction among the structure of stiffened plates,heat conduction differential equations and boundary conditions are established based on heat transfer theory,followed by the general FE solving method.For the size of workbench is large and its heat dissipation situation is complicated,based on heat and mass transfer and similarity theory,not only the natural convective heat transfer mathematical model of base and workbench is established,but also the model which suites large rotating disk convective heat transfer process is established.Based on heat transfer theory and FSI theory,FSI heat transfer model of hydrostatic bearing-workbench/base-air is established,including flow and heat transfer of liquid,heat transfer between solids and interaction between fluid and solid.And then based on the model,under the condition of considering oil variable viscosity and air buoyancy flow,the velocity range is 5?50rpm,the ambient temperature range is 5-25?,thermal field and its impact factors is numerical simulated through FSI method.Influence regularity of velocity and ambient temperature on heat generation and carrying capacity of hydrostatic bearing,on air flow and on heat dissipation situation of rotary-table is revealed,general temperature field of workbench and base is also gained.In order to verify heat conduction mathematical model and FSI numerical simulation,an experiment is designed for acquisition temperature field of workbench of double column vertical lathe DVT500×40/50 through infrared thermal imager,the temperature field of numerical simulation results of workbench top surface are consistent with experiment,moreover,the sampled temperature value of numerical simulation results on the specified path fit the experiment well,which would validate the mathematical model and numerical simulation,and would validate the application of FSI method is feasible in heavy vertical lathe rotary-table research.Through the research on thermal field of heavy vertical lathe rotary-table,the effect of thermal load effect and its impact factors is gained,the regularity of heat conduction and heat dissipation of workbench and base is revealed.Also,the application domain of FSI method is expanded and the conclusions can provide a reliable and accurate reference for designing and performance prediction of vertical lathe rotarv-table.