Research On The Dynamic Characteristics Of High Contact Ratio Gears Considering Precision Parameters

Gear is a very important transmission basic component.It is widely used in various industries because of its advantages of high transmission power,high transmission accuracy and strong load-carrying capacity.With the rapid development of automobile,engineering machinery,rail transportation equipment,robots and other fields,there is an increasing demand for the transmission performance of gear systems.The use of high contact ratio gears can effectively improve the bearing capacity,vibration,noise,reliability and other performance of gear system,but its dynamic meshing performance is very sensitive to the accuracy parameters due to its large number of teeth engaged in meshing.Therefore,this paper studies the dynamic characteristics of high contact ratio gear with precision parameters,which lays a foundation for the design and optimization of precision parameters of high contact ratio gear.The main research work completed in this paper is as follows:By analyzing the structure and characteristics of the tooth profile of hob for high contact ratio gear,the tooth profile equation of high contact ratio gear is derived based on the meshing principle,and the influence of different tool parameters on the tooth profile of high contact ratio gear is studied.The optimization algorithm is used to calculate the parameters of the hob and the actual tooth profile of high contact ratio gear is obtained.The calculation method of contact ratio based on the actual tooth profile is analyzed.The principle of calculating the meshing stiffness by potential energy method is analyzed.Based on the actual tooth profile of high contact ratio gear obtained above,the stiffness calculation model of high contact ratio gear is derived by the potential energy method and the calculation example is given.The influence of different factors on the stiffness of high contact ratio gear is analyzed.According to the analysis results,it can be seen the transition curve of the gear teeth,the trimming edge of the tooth,and the tooth thickness have a significant influence on the stiffness of high contact ratio gear.According to the characteristics of different precision parameters,the tooth surface mathematical model of high contact ratio gear considering the precision parameters is constructed.The tooth contact analysis method considering the precision parameters is studied.The correctness of the built model and the solution method is verified by some examples.The concept of gear pair integrated error(GPIE)is expounded.Based on the model established above,the influence of different precision parameters on gear pair integrated error is analyzed.A new nonlinear gear dynamics model including gear pair integrated error,time-varying mesh stiffness and backlash is established.The dynamic characteristics of traditional dynamic model and the new dynamic model under different conditions are compared and analyzed.The comparison results show that the new dynamic model can describe the system better than the traditional model.The nonlinear dynamic equations of high contact ratio gear based on gear pair integrated error are derived.The influence of different precision parameters on the dynamic characteristics of high contact ratio gear is analyzed.The influence of comprehensive precision parameters on the dynamic characteristics of high contact ratio gear is further analyzed.The analysis results show that,on the one hand,the dynamic response of the gear system caused by the combination of deviation parameters under different machining precisions may be similar;on the other hand,although the machining accuracy is the same,other characteristics of the deviation parameters may cause large differences in the dynamic characteristics of the gear system.Therefore,a tolerance analysis method for high contact ratio gears based on dynamic characteristics is proposed and an example analysis is carried out.