Research Of Gear System Dynamics Based On Time-varing Meshing Stiffness

Mining industry plays an important role in industrial development of our country and the mechanization and intellectualization have been a significant topic of China’s national policy for medium and long-term scientific development. Thereover, based on 973 project of Deep Dangerous Unmanned Mining Equipment Key Basic Research, the paper has studied dynamic characteristics of gear transmission system of mining equipment’s rocker arm which lay a foundation to reliability researches afterwards. The specific works are as follows:(1) The basic theory of gear mesh stiffness and transmission error is introduced. Meanwhile, an better gear pair mesh stiffness analytic method has been deduced according to existing papers which could somehow enhance the accuracy by improving the calculation form of tooth base stiffness.(2) the accurate modeling method of involute gears has been included via which a parametric Finite element Analysis gear-meshing model in Ansys is built. With such analysis model, not only the mesh stiffness variation of spur and helical gear pairs but contact stress distribution of a single helical gear tooth as well are studied and lay the foundation of gear dynamic research.(3) A 12 degree of freedom helical dynamic gear meshing model is set up considering mesh stiffness distribution and friction force along the contact lines. The response is analyzed after the length of contact lines and friction force arm are studied.(4) The conception of dynamic gear mesh stiffness is purposed and a type of dynamic gear mesh stiffness system model considering tooth errors due to modification is established. After the model was solved, relationships between responses of gear pair mesh stiffness, transmission error as well as meshing force and modification amount, load and speed are concluded.The paper improves calculation method of gear meshing stiffness to enhance the accuracy, studies the relationship of helical gear contact stress distribution and meshing stiffness, figures out the effect of friction force in gear meshing and effect of profile error in gear dynamic meshing stiffness response.