The Dynamic Characteristics Research On Non-circular Gears

Compared to traditional indexing mechanism,divided number of non-circular gear splitter is larger.Besides,it has other advantages,such as compact structure,precise transmission,higher efficiency and so on.However,one of the most important factors which effect its application range is that whether this machine could work regularly if it would be in condition of high velocity and overloading.The theories of design and manufacture for non-circular gear slicer which is in designing research stage is not mature and complete.The reason is that the design and manufacture of non-circular gear is very difficult.The current research on non-circular gear mainly focus on design,manufacturing and processing.The theoretical research on the dynamic characteristics of non-circular gear is rarely done.Therefore,It is necessary to study the dynamics of non-circular gear pair before studying the dynamics of non-circular gear slicer.In this dissertation,the dynamic characteristics on the non-circular gears of noncircular gear slicer is presented further analysis,and the following aspects are analyzed:Firstly,considering the time-varying meshing stiffness,the backlash and the meshing error of meshing geer in non-circular gear slicer,and ignoring the torsion stiffness of planetary shaft and the bearing stiffness of back-up bearing,the dynamic model of non-circle gear slicer is established by the lumped mass method and the second law of Newton.The focus is that the non-circular gear pair of non-circular gear slicer is established torsion vibration model.Because of the changed transmission ratio of non-circular gear in the model,the torsional vibration differential equation of the non-circular gear is difficult to solve directly.In this paper each pair of meshing teeth will be equivalent to cylindrical gear.Then the model is solved by using the MATLAB software and a meshing cycle solution is calculated.The output in the end of the meshing cycle is left as the initial condition of next meshing cycle.That the iterative solution of each meshing period is given and merged in the whole solution together is a turning period solution.Finally,the system response time history,phase diagram and spectrum analysis with different excitation frequency,meshing error and damping ratio are obtained by the numerical calculation.The effects of vibration excitation frequency,meshing error and damping ratiov in non-circular gear pair are analyzed and the basic vibration rules of non-circular gear explored.The three-dimensional model of non-circular gear is established by using the SolidWorks software.Then it is imported into the ADAMS software for dynamic simulation.Four groups experiments with different stiffness and damping are set up.through compareing and analyzing the simulation results of four groups experiments,the impact of stiffness and damping on the dynamics of non-circular gear is explored.Finally,the entity model of the non-circular gear is importe into ANSYS Workbench for transient dynamic analysis that the contact stress of non-circular gear is analyzed in the process of the transmission.At last,the modal analysis of non-circular planetary gear is carried out to analyze the first six order natural frequency and vibration mode.