An experimental study has been carried out on a transmission system which consists of a pair of spur gears mounted using ball bearings on a steel frame and rotated by a frequency controlled A-C electromotor.
The vibration sources among the rotating components of the system have been investigated using Campbell diagram technique and its influence on the frequency spectrum at the measuring points located on the frame has been identified. Harmonic as well as random excitation techniques have been conducted to reveal the transfer-function and the frequency spectrum at those measuring points.
It is observed, for low frequency range (up to 125 Hz) similar transfer functions are obtained through out the measuring points. On the other hand for high frequency (above 125 Hz) the transfer functions are significantly influenced by the local propagation path.