Research On Vibration Of Gear Transmission System Of Aero-Engine

This thesis focuses on the two-staged cylindrical spur-gear transmission system in accessory drive casing of aero-engine. Some researches on dynamic characteristics of the transmission system are accomplished.By using Lumped-mass Method, a coupling vibrant model that includes time-variant meshing stiffness, transmission errors and backlashes et al is established. According to the model, the non-linear dynamic differential equations with 8DOF and second order are established. The dimensionless form of the vibration equations is obtained. To obtain the structure parameters, stimulation of time-varying meshing stiffness and backlashes is acquired. And the figure of time-varying meshing stiffness and backlashes is drawn.Through the method of generalized Eigen value, the natural characteristics of system are analyzed and frequencies are solved. Employing the Runge-Kutta integration method, dynamic responses of the system are solved. Influence of the internal excitation is discussed in this thesis. The rules show that the dynamic responses of the system will become stable and, as internal excitation varies, the motion states experience a process from periodic motion to quasi-periodic motion, and then to periodic motion again.Based on the deduced formula of sensitivity, the curve and amplitude of sensitivity have been derived. According to the chart of the amplitude, influence of the structure parameters to the system is analyzed. By changing meshing error, amplitude of response and its curve are obtained. According to the curve, influence of meshing error to dynamic characteristics is studied. If dynamic characteristics of system don't meet design requirement, the structure parameters could be adjusted on the basis of influence. Based on the research on vibration of gear transmission system of aero-engine, it could provide ameliorated dynamic characteristics and guidance of design and manufacture of gear transmission system with high quality.