Lateral Gear Shaft Dynamics Control Torsional Stresses in Turbine-Driven Compressor Train

• Published in: Journal of engineering for gas turbines and power 1984-10, Vol.106 (4), p.946-951
• Main Authors: Simmons, H. R, Smalley, A. J
• Format: Article
• Language: English
• Subjects: Applied sciences; Continuous cycle engines: steam and gas turbines, jet engines; Energy; Energy. Thermal use of fuels; Engines and turbines; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Mechanical engineering. Machine design
• ISSN: 0742-4795; 1528-8919
• DOI: 10.1115/1.3239663

An experimental evaluation of a gas turbine/compressor train yielded excellent correlation between measured and predicted torsional critical speeds. Torsional strain signals acquired at a coupling location provide basic data from which damping factors at resonance are found to vary from 1 to 6 percent, depending on mode shape. Resonant stress levels for the mode with low damping would be a factor of 2 higher than predictions based on industry accepted assumptions. Other modes are found to have considerably more damping than expected. Experimental data and a coupled torsional-lateral damped eigenvalue analysis show that this damping variation is related to pinion and gear lateral bearing motion. Conservative damping values are predicted by the coupled analysis.