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http://dx.doi.org/10.9725/kstle-2012.28.6.265

Journal Bearing Design Retrofit for Process Large Motor-Generator - Part II : Rotordynamics Analysis  

Lee, An Sung (Dept. of System Dynamics Research, Mechanical Systems Safety Research Div. Korea Inst. of Machinery and Materials)
Publication Information
Tribology and Lubricants / v.28, no.6, 2012 , pp. 265-271 More about this Journal
Abstract
In the preceding Part I study, for improving the unbalance response vibration of a large PRT motor-generator rotor fundamentally by design, a series of design analyses were carried out for bearing improvement by retrofitting from original plain partial journal bearings, applied for operation at a rated speed of 1,800 rpm, to final tilting pad journal bearings. To satisfy evenly key basic lubrication performances such as the minimum lift-off speed and maximum oil-film temperature, a design solution of 5-pad tilting pad journal bearings and maximizing the direct stiffness by about two times has been achieved. In this Part II study, a detailed rotordynamic analysis of the large PRT motor-generator rotor-bearing system will be performed, applying both the original plain partial journal bearings and the retrofitted tilting pad journal bearings, to confirm the effect of rotordynamic vibration improvement after retrofitting. The results show that the rotor unbalance response vibrations with the tilting pad journal bearings are greatly reduced by as much as about one ninth of those with the plain partial journal bearings. In addition, for the tilting pad journal bearings there exist no critical speed up to the rated speed and just one instance of a concerned critical speed around the rated speed, whereas for the plain partial journal bearings there exist one instance of a critical speed up to the rated speed and two instances of concerned critical speeds around the rated speed.
Keywords
large motor-generator; plain partial journal bearing; tilting pad journal bearing; design retrofit; rotordynamics; unbalance response vibration; critical speed; mode shape; critical speed map; campbell diagram;
Citations & Related Records
Times Cited By KSCI : 3  (Citation Analysis)
연도 인용수 순위
1 하진웅, 명지호, 석진익, 이안성, 김영철, "5패드 틸팅 패드 베어링의 설계조건 변화가 소형 가스터빈의 횡진동 특성에 미치는 영향," 한국소음진동공학회논문집, 제21권, 제8호, pp. 752-760, 2011.
2 Lee, A. S. and Kim, B. O., "Influence of Bearing on the Rotordynamic Characteristics of Boiler Feed Water Booster Pumps," Proceedings of the 9th Asian International Conference on Fluid Machinery, Jeju, Oct. 16-19, 2007.
3 이안성, "프로세스 대형 모터-발전기의 저어널 베어링 설계 개선 - Part I: 베어링 성능개선," 한국윤활학회지, 제28권, 제5호, pp. 197-202 , 2012.
4 Nicholas, J. C., "Hydrodynamic Journal Bearing Types, Characteristics and Applications," Mini Course Notes - Vibration Institute, 20th Annual Meeting, St. Louis, Missouri, June 25-27, 1996.
5 Nicholas, J. C., "Tilting Pad Bearing Design," Proceedings of the 23rd Turbomachinery Symposium, Turbomachinery Lab., Texas A&M Univ. pp. 179- 194, 1994.
6 API Recommended Practice 684, API Standard Paragraph Rotordynamic Tutorial: Lateral Critical Speeds, Unbalance Response, Stability, Unbalance Responses, Stability, Train Torsionals, and Rotor Balancing, Chap. 2, Sect. 2.5, 2005.
7 이안성, 김창업, "LPLi 연료펌프 적용을 위한 저어널 베어링의 설계 적합성 연구," 한국윤활학회지, 제25권, 제5호, pp. 324-329, 2009.
8 이안성, 김병옥, "3-로브 베어링으로 지지된 중형 고속 터보차저 로터의 선형 및 비선형 동적 안정성 특성 규명," 한국소음진동공학 회논문집, 제21권, 제6호, pp. 562-569, 2011.   과학기술학회마을   DOI