Parameterized Profile Modification Of Involute Spur Gear

Meshing shock are generated during involute spur gear transmission period due to the influence of manufacturing error, installation error and base pitch error caused by the deformation of gear, which leads to transmission unstable which is the main cause of the vibration and noise. How to improve the running performance and bearing capacity of the gear aim to reduce the failure of gear is the main research direction for gear designer and manufacturer.Gear shape is very important to the transmission performance of gear. Nowadays different countries are exploring different tooth profiles and different processing technics for the purpose of reducing contact stress and obtaining easy processing high performance gear. Theoretical research and practical application indicate that if gear's shape of tooth profile were modified, its transmission performance would have been improved and its bearing capacity would have been increased. In this paper tooth profile is modified by using a new-type tooth profile curve—the transmutable arc for expecting transmission performance would have been improved.Firstly, the finite element theory used in analysis of gear contact, and the function and the characteristic of ANSYS was introduced, the characteristic and advantage of ansys parametric design language was introduced in detail. On the basis of the involutes curve equation and the dedendum transition curve equation, the three dimensional model of standard involute gear was established using the method of parametric modeling. Through the analysis of gear static contact in different place, gear contact stress and its changing regularity were obtained, which is the reference of the performance of modified gear.Secondly, the principle of how the transmutable arc was obtained and fundamental equation were introduced, meanwhile the theory of tooth profile modification was also introduced. Through coordinate transformation the coordinate of the transmutable arc was transformed to the coordinate system which the involutes curve was in, the mathematical model of using transmutable arc approximating involutes curve was established. Tooth profile Curve equation was obtained by calculating to mathematical model.Finally, the parameterized model of modified gear was established in ANSYS, through the static contact analysis of modified gear in the same constraints and load as standard involute gear, modified gear contact stress and its changing regularity were obtained. Compared with standard involute gear' contact stress in pitch line and changing regularity in the course of meshing, we can see that modified gear's static stress performance was improved slightly. Using the transmutable arc grinding wheel manufactured hard tooth surface gear, we can obtain high accuracy gear. meanwhile the transmutable arc grinding wheel was manufactured easy, so even the performance of modified gear was improved slightly, the purpose of the research was achieved.