Abstract: The vibration fault of a reducer is analyzed. A kind of coupled resonance of the intermediate transmission gear is discovered. A method of mode correction is suggested to improve the accuracy of the experimental mode based on the results of experimental modal analysis, modal synthesis technique and Rayleigh's method. Various modifications of the structure are analyzed. The optimal modification of them is chosen according to the calculated dynamic frequencies.

Key words: reducer, gear vibration, dynamic modification of the structure, mode correction