• CN: 11-2187/TH
  • ISSN: 0577-6686

Journal of Mechanical Engineering ›› 2025, Vol. 61 ›› Issue (3): 284-298.doi: 10.3901/JME.2025.03.284

Previous Articles    

Life Prediction of Planetary Gearbox Based on Competing Failure Mechanisms and Experimental Study

WANG Hanming1,2, DONG Qingbing1,2, CHEN Zhuang1,2, ZHAO Bo3, SHI Xiujiang4   

  1. 1. State Key Laboratory of Mechanical Transmission for Advanced Equipment, Chongqing University, Chongqing 400044;
    2. College of Mechanical and Vehicle Engineering, Chongqing University, Chongqing 400044;
    3. School of Marine Engineering and Technology, Sun Yat-sen University, Guangzhou 519000;
    4. College of Power and Energy Engineering, Harbin Engineering University, Harbin 150001
  • Received:2024-02-09 Revised:2024-08-13 Published:2025-03-12

Abstract: Gears are designed to carry out alternating loads during the transmission process, and the special structure of their involutes causes changes in the sliding/rolling ratio during the meshing process as well as changes in the friction performance caused by the morphology characteristics of the tooth surfaces, ultimately leading to contact fatigue or tooth root bending fatigue. The service life of planetary gear trains depends on the minimum life of various types of gears such as gear rings, planetary gears and sun gears under the competition of contact fatigue and bending fatigue. A finite element model is built up for a spur planetary geartrain, and the time-varying friction coefficient is taken into account. Critical plane methods based on the multi-axial fatigue criteria, such as Brown-Miller method, Fatemi-Socie method, Morrow method and Smith-Waston-Topper method are used to evaluate the fatigue crack initiation location and life distribution of competitive failure in planetary gear train. The residual stress from surface to core is fitted based on the experimentally measured hardness, and the fatigue parameters are then modified accordingly. Finally, fatigue tests are conducted for planetary gear trains under the same operating conditions to investigate the evolution process of surface pits on failed gears and verify the effectiveness and accuracy of the developed model. The results show that the contact fatigue strength of the gearbox is much lower than the bending fatigue strength. The Fatemi-Socie method has higher accuracy in evaluating the contact fatigue life of gears. The sun gear more likely suffers from contact fatigue compared with other gears due to its teeth meshing with different planetary gears in sequence, and pitting first occurs on the subsurface near the tooth root of the pitch line. The contact fatigue life and location considering residual stress are consistent with the experimental results. The modeling method developed in this study can provide insight into the life prediction of planetary gearboxes based on competitive failure fatigue, and the method can be used for the fatigue properties of other types of transmission components.

Key words: spur planetary gearbox, multi-axial fatigue, competing failure mechanism, residual stress, life prediction

CLC Number: