| Planetary roller screw is a kind of precise transmission mechanism,which can convert the rotational movement of the screw rod into the linear movement of the nut.It has the advantages of small structure size,large bearing capacity,high transmission precision,etc.It is widely used in civil market and military industry.in.However,the processing and manufacturing of precision threaded parts in China still face many technical problems.Precision planetary roller screws relied on imports to limit the development of transmission equipment in China.Therefore,this paper uses the hard turning technology to process the thread pair,analyzes the relevant mechanism of the thread processing process,establishes the finite element model,optimizes the cutting art parameters,and analyzes the row dynamics characteristics of the processing system,which is a high-quality planetary roller screw.Processing and manufacturing provide theoretical support.According to the phenomenon of chip-removing generated during thread turning,the turning tool is divided into the unit cutter model,the minimum energy method is used to establish the mathematical formula of the main cutting force,and the different feed methods and feed allocation methods are analyzed for thread turning.Influence;Based on the finite element correlation theory,selecting the solution method and parameters in the pre-processing,establish a simulation model for hard turning of the thread.The finite element software DEFORM is used for simulation calculation.The single factor analysis method is used to explore the influence of cutting parameters and tool geometry parameters on cutting force,cutting temperature and tool wear,and the mechanism of the wear was analyzed.The simulation results are verified by the turning test of the screw rod.The correctness;the establishment of a worn tool model,analysis of the impact of wear on the thread turning process,compare two methods of feed allocation,the material removal rate improvement method is more suitable for hard turning of the thread.Based on the simulation data,a linear regression analysis method is used to establish the relevant empirical formula;the tool life,machining efficiency and surface roughness are selected as objective functions,and constraints such as machine tool performance,workpiece quality,and tool usage are taken into account;and weights are assigned by the AHP method.The coefficients and the optimal value of the sub-objective function are solved,and the total objective function is established;the MATLAB genetic algorithm program is used to optimize the solution.Using ANSYS Workbench to perform modal analysis of the roller,screw,nut,and thread cutting tools,the natural frequencies and vibration patterns of each order are solved,and the influence of thread depth changes on the structural modes is analyzed;based on the results of modal analysis,each The harmonic response of the parts is analyzed to obtain the displacement response curves at different positions during the thread machining process,and the influence of different stiffnesses on the dynamic stiffness and vibration displacement of the structure is compared. |
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