Shalaan A. M. Alshammari¹, Mostafa M. Makrahy¹, Nouby M. Ghazaly^1,

The main objective of this study is to detect gearbox fault signals through vibration analysis. Experimental tests are carried out using several sets of gears under different speeds and constant load. Initially, helical gears are fixed in the gearbox test rig and signals are recorded using data acquisition systems to establish the baseline behavior of normal gears. Then, the normal gears are replaced by defective gears and signals are recorded for each one of the cases separately under the same condition. After that, four proposed techniques of measuring vibrations, namely; time domain, root mean square, crest factor, and kurtosis are employed to evaluate the gearbox defects. From experimental results, it is found that the vibration signals play a significant role in evaluation defects of the gearbox. Also, it is noticed that the peak to the peak value of the time domain fluctuates around the x-axis and increases with the shaft speed. Moreover, it is found that at fluctuating speed conditions, the root mean square, crest factor, and kurtosis approaches are to be clearly distinguished from time domain for normal and defective gears. Finally, it is found that the vibration amplitudes of the gearbox are increased resulting in increased tooth breakage and wear at different gearbox speed.

time domain, root mean square, crest factor, kurtosis, gearbox fault diagnosis