Deformation Analysis And Control Of Five-axis CNC Machining Of Small Module Spiral Bevel Gear

Spiral bevel gear has the advantages of high bearing capacity,high overlap coefficient and stable transmission.It is widely used in the fields of precision instruments,drilling equipment,heavy-duty vehicles,ocean going vessel and so on.At present,in the small module spiral bevel gear drive,the modified cycloid tooth profile is usually adopted,and the different processing methods are directly related to the accuracy of the profile.Due to the small size,the deformation of the tool and workpiece will happen.How to establish a reasonable tool path optimization algorithm and reduce the machining deformation is the realization of spiral bevel gear tooth profile surface numerical control key to high efficiency and high precision processing.In this paper,based on the small module spiral bevel gear as the research object,the theory and method of multi axis NC machining,the theory of cutter envelope surface,the two point offset method and the finite element numerical simulation technology are comprehensively applied to explore and control the machining deformation of tooth profile of spiral bevel gear.The research work is as follows:(1)Establishment of solid model of small module spiral bevel gear and planning of tool path for multi axis NC machining of tooth profile were carried out.Through using UG to model the spatial entities of spiral bevel gears and analysing the geometric and structural characteristics of the spiral bevel gear to determine the machining parameters and establish the tool path planning of multi axis NC machining.Based on the CAM module of UG software,the tool path planning is analyzed.(2)Tool path optimization and error analysis of gear profile milling were carried out.Based on the established tool path planning and single parameter ball race envelope theory,using MATLAB to build in the process of tooth profile surface side milling cutter envelope and to discretize tooth profile of flank milling of spiral bevel gear.Through the analysis between theoretical tooth surface and the tool envelope surface normal error,reducing the optimization of cutter shaft by the two-point offset method.The machining tool path in the side finish milling process is reestablished to reduce the error in the side milling process.(3)Analysis of machining deformation of spiral bevel gear tooth profile was implemented.Through the establishment of small side milling spiral bevel gear tooth profile surface deformation and the deformation of tool theory prediction model,combined with the milling force model and AdvantEdge PM simulation to calculate the theoretical deformation.Through using the ANSYS platform to import the real time milling force and establish the finite element model,analysing the tooth profile deformation and tool deformation in side milling.Through the comparison with theoretical prediction model,to explore the side milling deformation distribution of tooth surface and the cutting tool By using the AdvantEdge PM module to optimize the cutting parameters in the milling process,the milling force can be optimized,and the deformation error of the tooth surface and the cutter will be reduced.(4))Spiral bevel gear machining simulation and experimental validation were implemented.The tooth surface of spiral bevel gear is simulated based on Vericut7.3,and then it is measured by the machining test and three coordinate measuring instrument.The analysis of the error between the actual tooth surface and the theoretical tooth surface is carried out to verify the effectiveness of the tool path optimization and the control of machining deformation.The research of this paper provides a reference for high precision NC machining of small module spiral bevel gears and laid a theoretical foundation to improve level of small module spiral bevel gear NC machining technology in China.