Abstract
Gear rattle of multi-step helical gear system is treated. Mesh stiffness variations are considered in the system. The effects of the mesh stiffness variations and the ratio of static torque to dynamic one on the rattle are studied by numerical analysis. As a result, the followings were made clear. (1) Because of interaction of dynamic torque and mesh stiffness variation, resonances like gear noise occur in low frequency region, and the number of them is equals to that of natural frequencies. (2) In the gear rattles of this type and other type which generates because of small constant torque in extremely low frequency, the rattle of 1st-stage is dominant and that of 2nd-stage is generated by the 1st-stage rattle. (3) Nonlinear phenomena like chaos and higher harmonic resonance occur as in single-stage gear system.
