Study On The Design And Meshing Characteristics Of The Asymmetric Curvilinear Cylindrical Gears

In recent years,a new type of gear tooth line with great development potentiality is appeared,named as the curvilinear cylindrical gear.The curvilinear cylindrical gear is a kind of point contact cylindrical gear with arcuate tooth trace.In the middle section of the tooth width,the standard involute tooth shape is retained,and other positions are quasi involute.In Comparison with the common cylindrical gear,the curvilinear cylindrical gear has many outstanding advantages,such as high bending strength,high contact strength,insensitive to setting and machining error and so on.As a type of high-speed and heavy-load gear,the curvilinear cylindrical gear has a very broad application prospect and very important research value.On the other hand,the asymmetric gear with double pressure angles has a unique advantage in improving the bearing capacity of the gear.Therefore,in this paper,the curvilinear cylindrical gear based on the asymmetric design,an in-depth study in the processing principle,mathematical modeling,stress calculation and other technical issues is carried on.In this paper,the principle of different machining methods is introduced,and the mathematical model of the asymmetric curvilinear cylindrical gear is established based on the meshing theory and the differential geometry knowledge.Three different shapes of the root fillet is designed.Numerical simulation of tooth surface and tooth surface visualization is done.The tooth contact analysis of the asymmetric curvilinear cylindrical gear is completed through two methods,named as traditional TCA method and Ease-off TCA method.The simulation results show that the method of Ease-off TCA is correct and feasible.The TCA model considering the installation error is established,else,the meshing trajectory and contact patch of the asymmetric curvilinear cylindrical gear under different installation errors is calculated.In this paper,an approach for application of profile modification which can improve the meshing characteristics of asymmetric curvilinear gear has been investigated.The normal section of head-cutter is provided with parabolic profiles.The simulation results show that the meshing characteristics of the gear pair can be improved by the modification of the tooth profile of the asymmetric curvilinear cylindrical gear.The finite element analysis method is used to calculate the tooth root bending stress and contact stress of tooth surface.The results show that the bending and contact strength of the asymmetric curvilinear cylindrical gear are better than that of the symmetric curvilinear cylindrical gear.