Abstract: In practical working condition, the gear transmission system's dynamic performance is studied with the system identification method. The system identification difference equation model is developed by means of the research of the relationship between the spur gear rotational vibration and noise. This method can be used to describe the gear transmission system's dynamic performance. According to the relationship between the gear rotational vibration and gear tooth deformation, the gear profile modification curve is optimum designed and verified in the gear dynamic transmission error test rig. A new research method is developed in gear profile modification, noise reduction and dynamic optimum design. The research results are easily used in practical application.

Key words: Gear transmission, Optimum design, Profile modification, System identification