Dynamics Modeling And Noise Analysis For Helical Gears Coupled Modification And Friction Excitation

Gear transmission system is one of the most important and the most widely used mechanical transmission, and the design of high efficiency, low noise and high performance gear is the important target of gear research. The gear vibration noise caused by the dynamic meshing excitation is an important index for the dynamic characteristics for gears, also the hot topics in the research of gear transmission system.However, helical gear is complicated structure has complex tooth shape, due to reasons such as helical gear manufacturing error, assembling error, through the tooth modification can reduces the effect of manufacturing and assembly error etc. on dynamic incentive and vibration noise in a certain extent. Furthermore, the research shows that the friction excitation is also one of the main reasons for the vibration and noise of the gear transmission system, and its dynamic response is closely related to the vibration noise and the life of the gear. The stiffness and the friction excitation of the helical gears are changed with the tooth modification, and there has no research on effect of this on the dynamic response and vibration noise for helical gear system with tooth modification. Therefore, Dynamics modeling and vibration noise analysis for helical gears coupled modification and friction excitation. has important theoretical and practical value in engineering for grasp the nature of gear transmission system dynamics design, guidance of the development of low vibration, low noise of gear drive product.Helical gear transmission system is taken as the object of the research, based on analysis of the tooth profile modification and lead modification of gears tooth modification, helical gear time-varying mesh stiffness based on time-varying contact line for tooth and friction incentives, the coupled dynamic modeling with helical gear tooth modification and friction excitation is proposed to study internal dynamic excitation, dynamic response and vibration noise for helical gear transmission system. The main research work includes:① The best identified modification parameters for tooth profile linear modification, tooth profile parabolic modification and tooth lead crowning are determined by using Romax software, then the static transfer error of the helical gear system for the different tooth modification method is calculated, and the minimal peak-to-peak value of static transmission error for helical gear system is obtained.② Assuming load for helical gear uniformly distributed along direction of the contact line length, the time-varying contact line, time-varying friction force and the friction torque for helical gear system is calculated based calculation method of he time-varying contact line, time-varying friction force and the friction torque, and the influence of the different spiral angle and tooth contact width on the time-varying contact line, the time-varying friction and time-varying friction torque for helical gear transmission system is analyzed. By calculation method of meshing stiffness for helical gear system based on the tooth contact wire length of the helical gears, the meshing stiffness for the helical gears without modification and with modification is calculated..③ Considering the influence of tooth modification on stiffness excitation and friction excitation for helical gears, coupled dynamic modeling with helical gear tooth modification and friction excitation is proposed used lumped mass method, and the dynamic characteristics of helical gear system analyzed using Runge-Kutta method. And the effect of with and without friction excitation, no tooth modification and modification, different friction coefficient on dynamic characteristics of helical gear system is obtained.④ The acoustic boundary element model for helical gear system is proposed to calculate vibration noise pressure levels of helical gear system. And the effect of no tooth modification and modification, different friction coefficient on dynamic characteristics of helical gear system is analyzed.