Research on natural characteristics and loci veering of planetary gear transmissions

A simplified purely torsional concentrated parameter model of a single stage 2K-H spur planetary gear transmission(PGT) is developed.Based on this model,natural frequencies and vibration modes,which are classified into two groups: planet modes and rotational modes,are investigated.The unique characteristics of each type of modes are analytically investigated in detail.The reduced-order eigenvalue problem of each type of modes is studied and a closed form expression for natural modes of the PGT has been derived.According to the closed form expressions for natural modes,the natural frequency sensitivities to system parameters are rigorously investigated.Parameters under consideration include support and mesh stiffness,component mass,and moments of inertia.The phenomenon of loci veering is analyzed.With the modal strain energy method,the influence of loci veering on dynamic characteristic is studied and a loci veering criterion is derived.The conclusions are verified by simulation result.