An improved dynamic model of spur gears considering delayed meshing out of the contact point due to root crack

Tooth root crack generally causes large deformation of meshing gear pairs, which results in delayed meshing out of the contact point. In this paper, an improved dynamic model of spur gears considering delayed meshing out of the contact point due to root crack is proposed, which takes several factors of mesh stiffness, mesh damping coefficient and delayed meshing out force into account. The effects of different crack depths and angles on the dynamic characteristics of the gear system are investigated through various simulation and experimental tests. Further, the improved gear dynamic model is validated by comparison with acceleration responses obtained from the experimental test rig under different working conditions. The findings indicate that the acceleration responses of the improved dynamic model are consistent with experimental results, in both time and frequency domains under different crack depths and angles.