Investigation of mesh force features under different planet tooth faults in planetary gearboxes.

• Tooth faults affect the morphology of the mesh force. • Internal mesh forces under various planet tooth faults are calculated. • Mesh force features are validated via the tooth root strain signal. • This work provides the basis for planet tooth faults classification. The mesh force of planetary gearboxes is the major excitation source of vibration. Thus, comprehending how gear faults impact the mesh force is essential in identifying specific fault information from the vibration response for accurate fault diagnosis. In this paper, the internal mesh force and mesh stiffness models of the planetary gearbox are established to depict the influence mechanism of planet tooth faults on the internal mesh force. Further, the theoretical internal mesh force features are validated via the ring tooth root strain, where the strain simulation and measurement are carried out, and a strain separation method is developed to obtain the actual mesh force features. The experimental and theoretical results both demonstrate that different planet tooth faults exhibit specific phase and trend features in the internal mesh force, which provides a foundation for tooth fault classification in planetary gearboxes. [ABSTRACT FROM AUTHOR]