Cooling Water Pump Gearbox Diagnostics, Failure and Remedial Actions

Case StudiesFailure of an industrial scale bevel gear assemble in 2.5 years of its commissioning. The gear box drives a pumps rated at 16240m3/h at 47.5 meter of head. The unit developed an abnormal noise with slightly higher impacting (vibration waveform) on the gearbox. However upon inspection, increased back-lash (still in recommended limit) was observed on the unit and the machine was kept in operation. During a startup in March 2014, high cyclic impacting was observed in vibration waveform which indicated gearbox wear/damage. Upon inspection leading edge teeth of the bevel gearbox was found broken. Further investigation revealed increased backlash and change in contact area of the gears. The case study covers the complete RCA of GB failure and the remedial action taken on similar units installed on site