Improved analytical model for mesh stiffness calculation of cracked helical gear considering interactions between neighboring teeth

As one of the most typical fault forms of the helical gear, the crack will change the dynamic excitation and further affect the dynamic behaviors of the transmission systems. Due to the complicated structure of the helical gears, the coupling effect between the neighboring loaded teeth is usually ignored in the mesh stiffness calculation, making it considerably overestimated especially in the case of the crack fault. An improved mesh stiffness calculation method of helical gear with spatial crack is proposed to make up this gap. The interactions between the loaded neighboring teeth induced by the gear body flexibility were considered to improve the calculation accuracy and applicability. Besides, the load distribution law for the engaged cracked tooth along the tooth width and profile can be obtained. The results indicated that the mesh stiffness of the multi-tooth engagement calculation using this model could be further improved compared with the traditional methods. Finally, the effects of the helix angle, crack depth, and crack propagation length on the mesh stiffness and load distribution were investigated using the proposed method.