Gas Turbine Electric Generator Gearbox Vibration.

The article outlines an investigation into what was causing high axial gearbox vibration and radial engine vibration in a Solar gas turbine electric generator. It was found that the use of old coupling bolts during gearbox installation and a misalignment problem caused the above-average vibrations. Removing the gearbox revealed pitted and corroded input pinion gears. Replacing the gearbox reduced vibration overall, but the vibration level increased at the inboard bearing. When the gearbox coupling was disassembled and realigned, that vibration level decreased also. Charts and figures are included.