School of Mechanical Engineering;
Tianjin University;
300072 Tianjin;
China;
Key Laboratory of Mechanism Theory and Equipment Design of Ministry of Education;
Tianjin University;
Tianjin Key Laboratory of Nonlinear Dynamics and Control;
Tianjin University;
300072 Tianjin;
China;
Helical planetary ring gear; Typical vibration modes; Planet phasing; Sideband;