Analysis Of Tooth Profile Concave Error Based On Contact Deformation

Gear shaving is one of the main methods of gear finishing,which is widely used in gear machining.However,after the shaving gear is machined with the standard shaving cutter,the tooth profile concave phenomenon appears in the vicinity of the pitch circle of the gear tooth surface,especially in the large module,the number of teeth of the gear shaving is the most obvious,seriously affected the shaving gear tooth profile accuracy and transmission quality.For a long time,the research on the error of gear tooth profile is mainly focused on three aspects,That is,the change of the contact points near the pitch circle,the change of the cutting speed and the elastic plastic deformation of the gear shaving.At present,it is an important way to improve and eliminate the error of tooth profile Concave error to study the influencing factors and the law of the tooth profile Concave error,and then to reveal the mechanism of the tooth profile concave error.Shaving process is the engagement state without backlash,Through research and analysis,the meshing equation,contact line equation and contact trajectory equation of shaving process are deduced,and the meshing contact points and their distribution rules are obtained,An analytical study of shaving process is realized.The meshing model of meshing gear of shaving gear is established during shaving,and the instantaneous load magnitude,tooth surface contact deformation and tooth bending deformation at different engagement points of shaving gear tooth surface are solved,The mechanism of the influence of the load and deformation between the gear teeth on the concave error of the gear teeth in the shaving process is obtained.By using Hertz theory,the elastic and plastic stresses in the contact deformation region of shaving process are analyzed,and the formulas for calculating the elastic stress and residual plastic stress in the contact zone are put forward,the elastic yield limit stress values of the contact deformation region in the shaving process are obtained,as a criterion,the theoretical boundary value of the elastic deformation and plastic deformation of the contact region of the shaving gear is obtained.CATIA software is used to establish the three-dimensional model of the meshing state of the gear shaving process,and the model is integrated into the ABAQUS,the instantaneous contact stress of the gear tooth surface under different contact states is simulated by ABAQUS software,the analysis of the change and size of the contact stress between the tooth surfaces during the meshing contact,it is concluded that the variation of the contact stress and the contact stress of the gear surface in the shaving process have a serious effect on the tooth profile concave error.In this paper,the mathematical model of the instantaneous contact line is established,and the total length of the instantaneous contact line is analyzed,the instantaneous contact line formula is proposed to compute the instantaneous shaving force,the change of cutting force and the contact stress between the meshing surfaces of the shaving gear and the contact stress of the gear tooth surface are obtained,in order to solve the problem of the fluctuation of the shaving force and the contact stress between the meshing surfaces of the shaving process,to achieve the purpose of improving or eliminating the error of gear shaving.