Study On Vibration Characteristics And Contact Of Spiral Bevel Gear

Arc tooth bevel gears have more complex tooth surface structures than straight and helical gears,and the larger overlap ratio enables them to obtain stronger load-bearing capacity and smooth transmission.They have been widely used in the fields of automobile and ship manufacturing.Due to the complex structure of arc tooth bevel gears,there are many design parameters,and some parameters still need to be determined by experience.They are often in very important positions in machines,bearing high-speed and heavy-load requirements,which makes higher-level requirements for the strength and stiffness of arc tooth bevel gears.In order to ensure the reliability and stability of arc tooth bevel gear transmission,it is necessary to study the tooth surface contact and vibration characteristics of gears.Based on the conjugate surface theory,gear meshing principle and gear accuracy design requirements,this thesis establishes the tooth surface equations of large and small wheels of arc tooth bevel gears,uses numerical programming to solve the coordinates of discrete points of tooth surface projection,and draws the gear solid model and completes the assembly according to the calculated gear parameters using three-dimensional modeling software.Using finite element software,pre-processing of arc tooth bevel gears is carried out to establish a reasonable hexahedral mesh finite element analysis model,set appropriate boundary conditions and loading modes,and pave the way for contact analysis and vibration analysis of gear pairs.Using dynamic principle,dynamic contact analysis of arc tooth bevel gears is carried out.By analyzing the change curves of driven wheel speed and contact force with respect to speed,acceleration time,damping and inertia load,the influence of influencing factors on gear meshing performance is summarized.Aiming at the calculation method of transmission stiffness,the idea of discretization is introduced to calculate the single-tooth meshing stiffness by linear superposition of node meshing stiffness.The explicit dynamic analysis method is used to solve the contact force and elastic deformation at the contact point.Based on the established model,the dynamic meshing angular displacement of large and small wheels is analyzed to obtain the time-varying meshing stiffness and transmission error.The dynamic model of gear pair is constructed.Based on finite element method,the undamped free vibration equation of gear pair is solved to explore the inherent characteristics of gear pair and analyze the influence of meshing stiffness on natural frequency of gear pair.At the same time,taking vibration displacement and vibration acceleration as responses,the vibration characteristics of arc tooth bevel gears are explored.