Abstract
A thin-webbed gear is likely used for light-weigh characteristics of a transmission and its natural mode of vibration tend to excite exterior vibration and noise. Present paper deals with the experimental investigation of modal behavior using several helix angle gears at various torques and speeds. At first, it is clarified that the modal vibration having one diametral nodal line cannot be observed, and the second mode with two nodal lines is always markedly observed even it does not excited by mesh frequency. Also, third and fourth modes are observed only when it meets an excitation by mesh frequency. In addition, these modes are proven fixed to the spatial coordinate if the torque is applied to a certain amount. Secondly, the resonant frequency increases according to the increase in torque. Finally, position of nodal lines on driving and driven side are made clear, that are directed to near the mesh region but not in line.
