The shaft is supported at its ends through two needle bearings.
From this shaft the drive is transmitted to the bevel gear box by
means of a belt drive. The gear box is of dimension
150 mm 170 mm 120 mm and the full lubrication level is
110 mm and half lubrication level is 60 mm. SAE 40 oil was used
as a lubricant. An electromagnetic spring loaded disc brake was
used to load the gear wheel. A torque level of 8 N-m was applied
at the full load condition. The various defects are created in the
pinion wheels and the mating gear wheel is not disturbed. With
the sensor mounted on top of the gear box vibrations signals are
obtained for various conditions. The selected area is made flat
and smooth to ensure effective coupling. A piezoelectric accelerometer
(Dytran model) is mounted on the flat surface using direct
adhesive mounting technique. The accelerometer is connected to
the signal-conditioning unit (DACTRAN FFT analyzer), where the signal goes through the charge amplifier and an analogue-to-digital
converter (ADC). The vibration signal in digital form is fed to the
computer through a USB port. The software RT pro-series that
accompanies the signal-conditioning unit is used for recording
the signals directly in the computer’s secondary memory. The signal
is then read from the memory and replayed and processed to
extract different features.