A Study on Dynamic Behavior of the Oerlikon-type Spiral Bevel Gears. Rotational Vibration of Gears under Running Conditions.

Abstract

In the case of parallel axis gears (for instance spur gears, helical gears), it is clear that rotational vibrations of gears are mainly transmitted to the gear housing through gear shafts and bearings. Therefore it is necessary to improve them in order to reduce vibration of the gear housing. On the other hand, spiral bevel gears have been widely used as low noise gears among bevel gears. However, in the case of spiral bevel gears, there have been few studies dealing with dynamic behavior under running conditions, and little work has been done to clarify the mechanism of vibration of the gears and housing. Therefore it is necessary to clarify characteristics of vibration of spiral bevel gears to reduce vibrations of the gear housing. Thus, in this study, rotational acceleration of Oerilkon-type spiral bevel gears and vertical acceleration of the housing are measured under various conditions. At the same time, the root stresses are observed in order to assess the meshing condition of the gears. We conclude that it is important to estimate the rotational acceleration of geas in order to reduce vibration of the gear housing. It is found that rotational vibration of gears is related to the real contact ratio. In addition, we propose use of the free vibration to model the rotational motion of spiral bevel gears by means of equivalent spur gears. Results calculated using this model are in good agreement with experimental ones.