Multi-variable Coupling Nonlinear Dynamic Characteristics Research On A Planetary Reducer With Small Tooth Number Difference

This research subject stems from the National Natural Science Foundation of China “Application basic research of high reliable and high precision filtering gear drive unit for industrial robots”(51375506).With the rapid development of the aviation, aerospace, advanced manufacturing, robots and other engineering projects, the higher requirements of reducer as an important equipment of high performance transmission is put forward. The planetary gear reducer system is a multistage gear transmission system, it not only has the extrinsic incentives of complicated working condition, operation condition and load, but also has the internal incentives of time-varying meshing stiffness, mesh damping, gear transmission error, backlash, bearing supporting stiffness and damping, tooth surface friction, its dynamic and vibration characteristic are extremely complex. It is necessary to study the dynamic characteristics and coupling nonlinear vibration characteristics, which can provide certain reference for the design, optimize, analysis and manufacture of high performance planetary reducer gear transmission system.Aimed at a planetary reducer with small tooth number difference, firstly, the structure is analyzed, and three-dimensional model of reducer is established by Solid Works, secondly, the dynamic characteristics and nonlinear vibration characteristics simulation are analyzed by LMS Virtual lab software, then, the bending-torsion coupled 8 degrees nonlinear coupled vibration model of reducer is established by the lumped mass method, the nonlinear vibration modle is solved by numerical method, the nonlinear vibration characteristics of reducer and the influences of related parameters on the nonlinear vibration characteristics are analyzed, finally, the vibration characteristics are verified by experimental.The main contents of this paper are as follows:①The structure of the planetary reducer with small tooth number difference is analyzed, the dynamic characteristic parameters of rolling bearing supporting stiffness, support damping and time-varying mesh stiffness, mesh damping and shaft torsional stiffness, torsional damping are calculated.②The rigid dynamics model of reducer and the coupled dynamics model of reducer re established, the gear meshing force, vibration acceleration, structual noise of reducer are analyzed under different speed and load.③Considering the time-varying meshing stiffness, transmission error, backlash, gear shaft torsional stiffness and torsional damping, bearing supporting stiffness and damping, the bending-torsion coupled 8 degrees nonlinear coupled vibration model of reducer is established by the lumped mass method, the fourth-order fifth-grade RKF method is adopted to solve the nonlinear differential equations, the gear vibration displacements, velocity responses, and vibration displacement-velocity phase portraits, Poincaré sections, bifurcation, and elasticity viscous meshing forces of gear pair, bearing dynamic loads are analyzed, finally, the influences of various parameters on the nonlinear vibration characteristics of the reducer are analyzed.④The vibration experiments on the reducer is carried out to verify the accuracy of the simulation, through the three acceleration sensors to collect the vibration signal of the reducer fixed gear shell, the averages of vibration acceleration response of each measuring point are delived by charge amplifier amplification and analyed by the signal processing system, the corresponding vibration frequency can be obtained by FFT transform.