Static And Dynamic Characteristics Analysis And Structural Optimization Of Direct Drive CNC Turntable

In recent years,direct drive technology has been widely used in the field of CNC turntables.The direct drive CNC turntable designed according to past experience not only has shortcomings in static and dynamic performance,but also has a cumbersome structure.In order to solve such problems in the direct drive CNC turntable,This paper takes the self-developed direct drive CNC rotary table as the research object,and uses CAE/CAD technology to analyze the static and dynamic characteristics of the product and optimize the design.The main research contents of this paper are as follows:1?According to the working condition of the direct drive CNC rotary table,the milling force of the turntable and the hydraulic pressure and cutting torque of the key parts brake disc are calculated.Establish a three-dimensional parametric model of the turntable and generate a finite element analysis model by rationally simplifying the mesh.The static characteristics of the brake disc and the rotary table are statically analyzed to obtain the static characteristics,thereby verifying the strength and static stiffness of the brake disc and the rotary table.The accuracy was verified by conducting stress experiments and comparing the results of static analysis.2?Perform constrained modal analysis on the CNC turntable to obtain the natural frequencies and modes of the turntable to analyze the vibration performance of the turntable.Based on the modal analysis,the harmonic response analysis of the turntable is carried out to determine the dynamic response value of the turntable table at various frequencies when the milling force is loaded at different positions.Get the dynamic characteristics of the turntable.3?Select design variables for the brake disc and the CNC rotary table and determine the range of values.The CCD center point method is used to select experimental points for the brake disc and the turntable,and perform finite element analysis on each experimental point.The response relationship between the design variables of the brake disc and its mass and maximum stress and the response of the design variables of the turret to its maximum deformation,mass and first-order natural frequency are obtained,and the response surface model of the brake disc and the CNC rotary table is established.Thereby,the response surface model of the brake disc and the CNC rotary table is established.Laid the foundation for multi-objective optimization.4?According to the stress analysis results of the brake disc and the analysis results of the milling force and the maximum workpiece load stress of the turntable.Select objective function and constraint to establish mathematical model of optimization equation.Optimized Pareto solution set for multi-objective optimization design based on genetic algorithm for brake disc and turntable.According to the design needs to select the optimal solution,and based on the sensitivity analysis for design parameter correction.Comparative analysis before and after optimization shows:The maximum equivalent stress drop of the brake disc is 7.97%under the premise of no increase in mass.Under the premise that the maximum deformation and the first-order natural frequency do not increase,the quality of the turntable is reduced by 10.8%.The strength optimization target of the brake disc and the lightweight target of the turntable are realized..