Planetary gear with equally spaced planets is mostly used to achieve vibration and noise reduction. To investigate the internal mechanism of planet phasing, a time-varying mesh stiffness - static transmission error planet phasing model was proposed. The mesh stiffness and transmission error were expressed as Fourier series, and the mesh excitation of the central component was derived to reveal the relationship among mesh stiffness phasing term, transmission error phasing term and mesh excitation phasing term. Meanwhile, the mesh torque phasing theory of traditional planet phasing theory was modified by stating that vibration is suppressed when the mesh torque harmonic is zero. Numerical simulations were implemented to verify the modified planet phasing model. The results indicated that it agrees well to the traditional one except for the case that the mesh torque harmonic is zero. The proposed model incorporates the actual mesh stiffness and transmission error into planet meshing, which improves the compatibility between the study of planet phasing theory and the study of the internal mesh characteristics.
