Control And Matching Of Grinding Tooth Profile Deviation Of Cycloidal Bevel Gears

Cycloidal spiral bevel gears are machined by face-hobbing method,which can process both sides of the teeth simultaneously in a cutting cycle.This method has high machining accuracy and efficiency,and is easy to realize dry cutting.It is more and more widely used in mass production.However,due to the determination of forming principle,cycloidal spiral bevel gears cannot grind their teeth after heat treatment.Spiral bevel gears with spiral teeth are machined by face-milling method with single tooth indexing.Only one tooth can be machined in one process,but it is easy to grind.If the production surface of spiral bevel gear with spiral teeth is approximately replaced by that of cycloidal bevel gear,it is possible to grind cycloidal spiral bevel gears by using the grinding method of arc teeth.Because of the difference of their forming principle,the theoretical deviation will occur after approximate replacement of the Cycloidal Tooth surface.If the deviation control is unreasonable,the contact performance of the gear pair after grinding is poor,and even worse,it will be discarded directly.Aiming at this problem,this paper studies the control method of tooth profile deviation in grinding cycloid spiral bevel gears.Considering that when the control of tooth profile deviation of Pinion is not ideal,the grinding gear pair with better transmission performance can be obtained by changing the tooth profile of Gear to match the grinding surface of Pinion.The main contents of this paper are as follows:1.By analyzing the basic processing principle of face-hobbing method,the mathematical model of the theoretical tooth surface equation of cycloidal spiral bevel gears was established.The basic processing principle of face-milling method was analyzed,and the mathematical model of grinding tooth surface equation of cycloidal spiral bevel gear with straight edge and circular arc edge grinding wheel was established.On this basis,the calculation model of tooth profile deviation of cycloidal gear grinding was established.2.The grinding errors of straight-edged grinding wheel and arc-edged grinding wheel were analyzed,the geometric shape of grinding wheel was determined,and the influence of the geometric parameters of grinding wheel on the tooth profile deviation was analyzed.The influence of adjustment parameters and higher order coefficients of machine tools on the correction of grinding tooth deviation was analyzed,and the higher order coefficients of adjustment parameters of machine tools were determined.3.The mathematical model for solving the contact characteristics of gears was established,and the objective optimization function for grinding deviation of generative cycloidal teeth(Pinion)was established.A model for solving the conjugate tooth surface of gears was established.Based on the principle of conjugate differential curvature,the matching objective optimization function of forming method or generating method(Gear)was established,aiming at the contact characteristics of the tooth surface of gears.4.The theoretical method mentioned above was illustrated by the full generation gear pair,and the contact area of the gear pair after grinding was analyzed and verified by the finite element analysis method.The tool position calculation model of CNC gear grinding was established,and the grinding simulation platform was established in VERICUT software.The grinding simulation experiment of an actual gear pair was carried out.Through the research of this paper,the better grinding parameters of cycloidal spiral bevel gears can be obtained preliminarily,which provides a reference value for further research.