Research Papers: Gas Turbines: Turbomachinery

Physical Analysis of Rotor-to-Stator Rub in a Large-Capacity Low-Pressure Steam Turbogenerator

[+] Author and Article Information
Seogju Cha

Department of Mechanical Engineering,
Korea University,
1 ga, Anam-dong, Seongbuk-gu,
Seoul 136-713, South Korea
e-mail: chaseog@naver.com

Sungsoo Na

Department of Mechanical Engineering,
Korea University,
1 ga, Anam-dong, Seongbuk-gu,
Seoul 136-713, South Korea
e-mail: nass@korea.ac.kr

1Corresponding author.

Contributed by the Turbomachinery Committee of ASME for publication in the JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER. Manuscript received April 27, 2015; final manuscript received December 19, 2015; published online February 17, 2016. Editor: David Wisler.

J. Eng. Gas Turbines Power 138(7), 072605 (Feb 17, 2016) (6 pages) Paper No: GTP-15-1147; doi: 10.1115/1.4032415 History: Received April 27, 2015; Revised December 19, 2015

Excessive vibration in large-capacity turbine generators can lead to expensive repairs and downtime with associated loss of operational income. Therefore, it is vital to detect the rubbing location in the rotor system at an early stage. The challenge is in achieving this without the expense and labor of complete disassembly. In this study, we present a practical tool for estimating the rubbing locations in a large-capacity rotor system from the shaft vibration patterns at each bearing. The measurement and analysis were performed on the rotor system of an 800-MW class large-capacity turbine generator. Three vibration patterns were observed in the machine operating on-site and were explained in terms of vibration modal analysis and the unbalance response characteristics to identify the rubbing locations. These results will be of interest to industrial engineers and have the potential to increase savings in operation costs.

Copyright © 2016 by ASME
Your Session has timed out. Please sign back in to continue.


Newkirk, B. L. , 1926, “ Shaft Rubbing: Relative Freedom of Rotor Shafts From Sensitiveness to Rubbing Contact When Running Above Their Critical Speeds,” Mech. Eng., 48(8), pp. 830–832.
Eckert, L. , and Schmied, J. , 2008, “ Spiral Vibration of a Turbogenerator Set: Case History, Stability Analysis, Measurements, and Operational Experience,” ASME J. Eng. Gas Turbines Power, 130(1), p. 012509. [CrossRef]
Bachschmid, N. , Pennacchi, P. , and Vania, A. , 2004, “ Rotor-to-Stator Rub Causing Spiral Vibrations—Modelling and Validation of Experimental Data on a Real Rotating Machine,” 8th International Conference on Vibrations in Rotating Machinery, Swansea, UK, Sept. 7–9, Professional Engineering Publishing, Bury St. Edmunds, UK, pp. 671–680.
Wu, J. , Legrand, M. , and Pierre, C. , 2010, “ Non-Synchronous Vibration of a Jeffcott Rotor Due to Internal Radial Clearance in Roller Bearings,” 8th IFToMM International Conference on Rotor Dynamics, Seoul, Korea, Sept. 12–15, Curran Associates, Red Hook, NY, pp. 398–405.
Patel, T. H. , and Darpe, A. K. , 2009, “ Study of Coast-Up Vibration Response for Rub Detection,” Mech. Mach. Theory, 44(8), pp. 1570–1579. [CrossRef]
Jeng, J. D. , Kang, Y. , and Chang, Y. P. , 2009, “ An Alternative Poincaré Section for High-Order Harmonic and Chaotic Responses of a Rubbing Rotor,” J. Sound Vib., 328(1–2), pp. 191–202. [CrossRef]
Shang, Z. , Jiang, J. , and Hong, L. , 2011, “ The Global Responses Characteristics of a Rotor/Stator Rubbing System With Dry Friction Effects,” J. Sound Vib., 330(10), pp. 2150–2160. [CrossRef]
Cheng, J. , Yu, D. , Tang, J. , and Yang, Y. , 2009, “ Local Rub-Impact Fault Diagnosis of the Rotor Systems Based on EMD,” Mech. Mach. Theory, 44(4), pp. 784–791. [CrossRef]
Yuan, Z. , Chu, F. , Wang, S. , and Yue, X. , 2007, “ Influence of Rotor's Radial Rub-Impact on Imbalance Responses,” Mech. Mach. Theory, 42(12), pp. 1663–1667. [CrossRef]
Pennacchi, P. , Bachschmid, N. , and Tanzi, E. , 2009, “ Light and Short Arc Rubs in Rotating Machines: Experimental Tests and Modelling,” Mech. Syst. Signal Process., 23(7), pp. 2205–2227. [CrossRef]
Taylor, H. D. , 2004, “ Rubbing Shafts Above and Below the Resonance Speed (Critical Speed),” General Electric Co., Schenectady, NY, Technical Report No. R-16709.
Dimarogonas, A. D. , and Paipetis, S. A. , 1983, Analytical Methods in Rotor Dynamics, Applied Science Publishers, London, UK.
Yamada, M. , Yasuda, C. , Katsuya, Y. , and Hiroshi, K. , 2000, “ Study on Heat-Flow-Induced Vibration of Rotating Machines (Part 1: Rubbing Vibration),” Dynamics and Design Conference 2000, Japan Society of Mechanical Engineers, Tokyo, pp. 958–962 (in Japanese).
Watanabe, T. , 1996, “ Thermal Vibration Balancing Method for Turbine Generator Rotor (Rotor Vibration Analysis Method Due to Thermal Unbalance),” Trans. Jpn. Soc. Mech. Eng., Ser. C, 62(599), pp. 2528–2535 (in Japanese). [CrossRef]
Watanabe, T. , Ishizuka, T. , and Fujisawa, F. , 1998, “ Rotor Vibration Due to Rubbing of Generator Hydrogen Gas Seal Ring,” Trans. Jpn. Soc. Mech. Eng., Ser. C, 64(617), pp. 98–104 (in Japanese). [CrossRef]
Bachschmid, N. , Pennacchi, P. , and Vania, A. , 2007, “ Thermally Induced Vibrations Due to Rub in Real Rotors,” J. Sound Vib., 299(4–5), pp. 683–719. [CrossRef]
Roques, S. , Legrand, M. , Cartraud, P. , Stoisser, C. , and Pierre, C. , 2010, “ Modeling of a Rotor Speed Transient Response With Radial Rubbing,” J. Sound Vib., 329(5), pp. 527–546. [CrossRef]
Patel, T. H. , and Darpe, A. K. , 2009, “ Coupled Bending-Torsional Vibration Analysis of Rotor With Rub and Crack,” J. Sound Vib., 326(3–5), pp. 740–752. [CrossRef]
Jacquet-Richardet, G. , Torkhani, M. , Cartraud, P. , Thouverez, F. , Nouri Baranger, T. , Herran, M. , Gibert, C. , Baguet, S. , Almeida, P. , and Peletan, L. , 2013, “ Rotor to Stator Contacts in Turbomachines: Review and Application,” Mech. Syst. Signal Process., 40(2), pp. 401–420. [CrossRef]
Ziaei-Rad, S. , Imregun, M. , and Kouchaki, E. , 2010, “ Thermoelastic Modeling of Rotor Response With Shaft Rub,” ASME J. Appl. Mech., 77(6), p. 061010. [CrossRef]
Pennacchi, P. , and Vania, A. , 2007, “ Analysis of Rotor-to-Stator Rub in a Large Steam Turbogenerator,” Int. J. Rotating Mach., 2007, p. 90631. [CrossRef]
Torkhani, M. , May, L. , and Voinis, P. , 2012, “ Light, Medium, and Heavy Partial Rubs During Speed Transients of Rotating Machines: Numerical Simulation and Experimental Observation,” Mech. Syst. Signal Process., 29, pp. 45–66. [CrossRef]


Grahic Jump Location
Fig. 1

The shaft supporting condition

Grahic Jump Location
Fig. 2

The rotor shaft elliptical vibration

Grahic Jump Location
Fig. 3

Lateral vibration of a beam element

Grahic Jump Location
Fig. 6

Vibration components in the x-direction

Grahic Jump Location
Fig. 5

Machine train diagram and the pickup positions

Grahic Jump Location
Fig. 4

A large turbine generator

Grahic Jump Location
Fig. 7

Vibration patterns of an 800-MW turbine generator due to rubbing (∠ is the phase angle (deg) and - is the amplitude (0-to-peak, μm)): (a) pattern A, (b) pattern B, and (c) pattern C

Grahic Jump Location
Fig. 8

Unbalance positions and vibration magnitudes

Grahic Jump Location
Fig. 9

Vibration responses due to rubbing: (a) pattern A, (b) pattern B, and (c) pattern C




Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In