When a gear system is running at a low speed, a “rattling” gear knock, called rattling, often occurs.The decibel value of this noise may not be very high, but the human ear is very sensitive to it, which seriously affects the overall sound quality.Unlike the excitation mechanism of gear squealing noise, a lot of studies have shown that the knocking noise is mainly caused by the fluctuation of driving torque and the existence of tooth side clearance. Repeated impact noise is generated between the teeth. At the same time, the knocking vibration can also be transmitted to the gear box through the gear body, drive shaft and bearing, which causes the thin-wall vibration of the gear box and thus generates the radiated noise.
The research on the knocking phenomenon of gear drive starts with a single pair of teeth at first. Many scholars at home and abroad have paid attention to the non-linear problem caused by gear backlash.Among foreign scholars, Comparin et al. and Karaman et al. respectively studied single degree of freedom and 3-4 of time-invariant meshing stiffness with tooth side clearance and time-invariant meshing stiffness.Vibration of gear system with degree of freedom is discussed. The influence of parameters such as ratio of bearing stiffness to meshing stiffness, ratio of load static component to alternating component, ratio of bearing load to preloading load on non-linear vibration characteristics of the system is analyzed, and the criteria for classifying steady-state solutions (chaos solution, quasi-periodic solution and sub-harmonic solution) are established. Two typical gearing systems leading to chaos are obtained.The road.
Padmanabhan andBased on previous research, Singh uses numerical simulation to prove the existence of harmonic, periodic and chaotic solutions, then obtains the approximate solution of excitation frequency by harmonic balance method, and uses this approximate solution to distinguish weak non-linear, medium non-linear and strong non-linear frequency response coupling. The influence of damping ratio, average load, alternating load and bandwidth between resonance frequencies is discussed.