GEARBOX MISALIGNMENT ON A COMBUSTION GAS TURBINE GENERATOR

摘要

This paper documents a vibration analysis of a Gas Turbine Load Gearbox that experienced high vibration on the High Speed Shaft (HSS) guide bearing reaching 5.2 mils (Pk-Pk). The relative direct amplitudes remained high over long-term operation with dominant IX frequency component. The cause of the high vibration was identified as external misalignment between the Gas Turbine and the Load Gearbox HSS. Investigation of the misalignment root cause revealed that the main contributor of the alignment issue was a defective leg of the Gas Turbine. All vibration plots (orbit, spectrum, startup trend, shaft centerline) & alignment figures will be presented in the paper.