고속 전동기용 2 패드 빔 타입 가스 포일 저널 베어링의 회전체동역학 성능 측정
Rotordynamic Performance Measurements of a Two-Pad Beam-Type Gas Foil Journal Bearing for High Speed Motors
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This paper presents experimental measurements of the structural characteristics of a two-pad beam-type gas foil journal bearing and its rotordynamic performance for a high-speed motor-driven turbocompressor. The test bearing had two top foils and two beam foils, each with an arc length of ~180°. Each beam foil was etched to obtain 40 beams with six geometries of different lengths and widths. The insertion of beam foils into the bearing housing produces equivalent beam heights. The structural tests of the bearing with a non-rotating journal revealed a smaller bearing clearance and larger structural stiffness for the load-on-pad configuration than for the load-between-pads configuration. Rotordynamic performance measurements during driving tests up to 100 krpm demonstrated synchronous vibrations and subsynchronous vibrations with large amplitudes. The test was repeated after inserting the shim between the top foil and beam foil to reduce the bearing radial clearance. The reduced bearing clearance resulted in a reduction in the peak amplitude of the synchronous vibrations and an increase in the speed at which the peak amplitude occurred. In addition, the onset speed and amplitude of the subsynchronous vibrations were dramatically increased and diminished, respectively. The rotor coast-down tests at 100 krpm show that the reduction in the bearing clearance extends the time to rotor stop, thus implying an improvement in hydrodynamic pressure generation and a reduction in bearing frictional torque.
Abstract
This paper presents experimental measurements of the structural characteristics of a two-pad beam-type gas foil journal bearing and its rotordynamic performance for a high-speed motor-driven turbocompressor. The test bearing had two top foils and two beam foils, each with an arc length of ~180°. Each beam foil was etched to obtain 40 beams with six geometries of different lengths and widths. The insertion of beam foils into the bearing housing produces equivalent beam heights. The structural tests of the bearing with a non-rotating journal revealed a smaller bearing clearance and larger structural stiffness for the load-on-pad configuration than for the load-between-pads configuration. Rotordynamic performance measurements during driving tests up to 100 krpm demonstrated synchronous vibrations and subsynchronous vibrations with large amplitudes. The test was repeated after inserting the shim between the top foil and beam foil to reduce the bearing radial clearance. The reduced bearing clearance resulted in a reduction in the peak amplitude of the synchronous vibrations and an increase in the speed at which the peak amplitude occurred. In addition, the onset speed and amplitude of the subsynchronous vibrations were dramatically increased and diminished, respectively. The rotor coast-down tests at 100 krpm show that the reduction in the bearing clearance extends the time to rotor stop, thus implying an improvement in hydrodynamic pressure generation and a reduction in bearing frictional torque.
참고문헌 (15)
- Rubio, D, "Bump-Type Foil Bearing Structural Stiffness : Experiments and Predictions", ASME J. Eng. Gas Turbines Power, 128, pp.653~660 (2006)
- San Andres, L, "Forced Nonlinear Response of Gas Foil Bearing Supported Rotors", Tribology International, 41(8), pp.704~715 (2008)
- Kim, T. H, "Effects of a Mechanical Preload on the Dynamic Force Response of Gas Foil Bearings : Measurements and Model Predictions", STLE Tribol. Trans, 52(4), pp.569~580 (2009)
- Sim, K, "Rotordynamic Performance of Shimmed Gas Foil Bearings for Oil-Free Turbochargers", Journal of Tribology, 134, pp.031102~ (2012)
- Sim, K, "Effects of Mechanical Preload and Bearing Clearance on Rotordynamic Performance of Lobed GasFoil Bearings for Oil-Free Turbochargers", Tribology Transactions, 56, pp.224~235 (2013)
- 황성호, "심포일을 갖는 가스 포일 저널 베어링의 성능 예측", 한국트라이볼로지학회지, 34(3), pp.107~114 (2018), 한국트라이볼로지학회[DOI]
- 황성호, "가스 포일 베어링으로 지지되는 연료전지 전기자동차용 공기압축기의 회전체동역학적 성능 측정 및 예측", 한국트라이볼로지학회지, 35(1), pp.44~51 (2019), 한국트라이볼로지학회[DOI]
- 김태호, "수소전기차용 공기압축기의 NVH 특성 규명", 한국소음진동공학회논문집, 29(3), pp.368~378 (2019), 한국소음진동공학회[DOI]
- Robert W. B, "Compliant Foil Hydrodynamic Fluid Film Radal Bearing, US Patent No.5427455", ~ (1995)
- Feng, K, "Design and Structural Performance Measurements of a Novel Multi-cantilever Foil Bearing", Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 229(10), pp.1830~1838 (2015)
- Swanson, E. E, "The Wing Foil : A Novel Compliant Radial Foil Bearing Design", J. Eng. Gas Turbines Power, 140, pp.082701~ (2018)
- Wilkes, J. C, "Impact of Bearing Clearance on Measured Stiffness and Damping Coefficients and Thermal Performance of a High-Stiffness Generation 3 Foil Journal Bearing", J. Eng. Gas Turbines Power, 140, pp.072503~ (2018)
- 백두산, "고속 전동기용 무급유 포일 저널 베어링 구조체의 하중지지 및 진동 특성 규명", 한국트라이볼로지학회지, 37(6), pp.261~272 (2021), 한국트라이볼로지학회[DOI]
- 백두산, "무급유 포일 베어링으로 지지되는 소형 전동 압축기의회전체동역학 성능 측정 및 예측", 한국트라이볼로지학회지, 38(2), pp.53~62 (2022), 한국트라이볼로지학회
- "ISO Standard 1940, “Mechanical Vibration – Balance Quality Requirements of Rigid Rotors, Part I: Determination of Permissible Residual Unbalance,”", ~ (1998)