Failure, Repair and Overhaul of 5 MW Right Angle Reduction Gear Box

Case StudiesL-1403A &B are 5 MW Right Angle –Double reductions gearboxes installed between Turbine (TP-1403) and Cooling water Pump (P-1403). Both gearboxes reported high vibration after 15 months of continuous operation one after the other. Vibration had a continuous increasing trend. CSI® was used to check the gearboxes that both showed looseness spectrum. During inspection of L-1403 B Gear Box, broken tooth of LS Bevel Gear was observed. While L-1403 A inspection revealed pitting on HS gears. Gearboxes were repaired in house by increasing interference of bevel pinion with shaft