| Planetary gear sets are widely used in various fields due to their excellent transmission performance. However, the vibration and noise are two key factors that affect the work efficiency and service life. In order to suppress the damping noise fundamentally and improve the power weight ratio, it is imperative to investigate the dynamics mechanism of the gear transmission set in depth. On condition of above, this paper will study the free vibration characteristics, mode mutation, nonlinear dynamic response as well as the effects of gear wearing on the dynamic responses of the supr planetary gear sets. The content of the paper is organized as the followings:Firstly, the main design parameters and nonlinear factors of the planetary gear set are calculated. A translational-rotation coupling model including the backlashes viscous damping, error excitation and components deformations established based on the carrier attached coordinated system. The deformation compatibility conditions are calculated. The differential equations are deduced by using the Newton’s second law combinding with movement characteristics of every degree freedom.Then, the natural characteristics of the planetary gear transmission set are investigated by us ing the numerical simulation method. According to the characteristic value of multiplicity of the natural frequencies and the displacement coordinate relationship, the natural characteristics of the NGW planetary gear transmission set can be divided into three categories. The influences of the main design parameters on the natural frequencies are investigated by us ing the control variable method. Two kinds of modal mutation phenomena are found through comparing the natural frequency curves. The principle of the two kinds of modal mutation phenomena were revealed, as w ell as the criterions are given through referring to the couping factor. The influences of the loci mutation on t he modal energy and modal sensitivity are analyzed. The correctness of the conclusions were verified by the simulation of an example.Thirdly, The nonlinear dimensionless motion equations are deduced by using the nondimensional parameters which are solved by t he fourth-order varying step integration method after liner transforming. Combined with the time-history, poincare section, spectrum and bifurcation diagram, the effects of the excitation frequency, the meshing damping, the backlashes and the initial values on the nonlinear dynamic characteristics are analyzed. The way to chaos of the system is explored with the bifurcation diagram.A wear model of the spur planetary gear set is established by using the Hertz contact theory combined with Archard wear principle. Based on the wear model, the wearing properties of the planetary gear set are investigated as well as the effects of the working parameters on t he tooth surfaces. The conclusions about the planetary gear wearing are drawn. In addition, the influences of wearing on the time-varying meshing stiffness and comprehensive meshing errors are analyzed. The characteristics of the wearing on the planetary gear set are studied through taking the results into the nonlinear dynamic model in further.Finally, in order to verify the correctness of the model mentioned above, a multi-body dynamic model is established in ADAMS, and the results are compared with the lumped parameter model. In further, a back-to-back type spur gear transmission set vibration test bed is set up b ased on the communication feedback loading system and the vibration characteristics are tested.The research of this paper reveals the effects of the design parameters on t he model characteristics. The energy sensitivity is mastered which can provide theoretical guidance for selecting reasonable parameters to avoid the modal mutation area. By using the model established in this paper the nonlinear dynamic characteristics of the planetary gear train set can be effectively evaluated. In addition, the effects of the wearing on the characteristics of the train set are investigated by combing the wearing model and the nonlinear dynamic model. The work of this paper provides theoretical foundation for the research of the other types of the gear transimission set and indicates the direction of the research of the interation mechanisn of the wearing and dynamic behavior of the planetary gear set. |
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