Investigation on double shock in vibration response of the gear pair with spalling defects

As an important component, the gear pair is frequently used in the mechanical transmission. If there is a localized spalling defect on the gear pair, the double shock phenomenon in the vibration response can be observed. In order to reveal the mechanism, an 8DOFs dynamic model for the gear pair is established, the symmetric and asymmetric rectangular spalling defects are considered, the torsional deformation is introduced. Meanwhile, the change law of the double shock during the defect expansion is explored. From the results, the double shock is caused by multiple changes in meshing stiffness, the amplitude and distribution range are closely related to the defect sizes. When the localized defect is extended along the length and depth directions, the amplitude of the double shock is significantly increased. If the defect area is asymmetric along the center plane, the torsional deformation of the gear pair will be generated. Then, the meshing stiffness is reduced, and the double shock becomes more obvious. Finally, through the finite element method and the experiment, the established model is confirmed.