Abstract
This paper proposes a relatively simple method for estimating the planetary gear noise by predicting vibration of an automatic transmission (AT) with good accuracy. In the proposed method, the exciting force is calculated based on transmission error analysis, the vibration transfer characteristics from the excitation points to the observation points on the AT case is analyzed with FE model, and then AT case vibration characteristics are defined as the product of these two values. A comparison of the vibration levels predicted with this method and the experimental results measured for an actual AT case confirmed that the proposed method can predict AT case vibration characteristics simply and accurately. The useful insights gained from a case study are also discussed.