Design And Simulation Of Double Gear And Rack Transmission Feeding Mechanism For Heavy CNC Lathe

Feed system is the very important part on the CNC lathe,most of them adopt servo motor to drive the ball screw pair,when the machine with the travel is more than 6 m,longer length of the ball screw will bring bigger deflection,also it will cause bending deformation making the movement positioning out of tolerance of tool post;At the same time,with the extension of ball screw,the inertia of the mechanical part increased,so increases the production cost,and reduce the reliability of the machine tool.In order to solve these all above problem,through researching and connecting with the domestic and foreign advanced design concept,also after many experiments of argument,the big and heavy duty CNC machine tools with the travel is more than 6m,longitudinal feed transmission adopts the design method of the double gear rack transmission.In this paper,the influence of the gears' side clearance on the transmission precision is analyzed,and studied the impact theory of gear dynamic load and the impact of the side gap in the process of gear meshing.Also put forward various institution of elimination reverse clearance,which is formed in gear transmission.Due to the gear backlash,it will cause the driving backlash,non-linear transmission and the oscillation of the system,and transmission accuracy is not very high.When the transmission is not smooth,seriously affected the transmission precision of the CNC lathe.For this reason,this paper analyzes the methods and characteristics of the various kinds of clearance mechanisms,and puts forward the method of the clearance of double gear output transmission.Second,researching eliminating clearance institutions in the process of double pinion and rack transmission,and comparing the design principle of the double gear backlash.Then choose disc springs to automatically adjust,Meanwhile it will makes the two output shaft gear meshing to eliminate the backlash,this method has the simple structure,low maintenance cost,and it is convenient to control.Finally,this study is based on Solidworks modeling,assembly and motion simulation of collaborative design,movement simulation analysis was carried out on the double gear backlash through ANSYS software,draw relevant motion analysis curve,analysis the effect of anti-backlash gear backlash.Based on the design of CK61250 heavy-duty lathe,this paper has been verified in practical,which proves the rationality and feasibility of the research of double gear rack feed mechanism.