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http://dx.doi.org/10.9725/kts.2022.38.5.205

Rotordynamic Performance Measurements of a Two-Pad Beam-Type Gas Foil Journal Bearing for High Speed Motors  

Jeong, Kwon Jong (Graduate School, Dept. of Mechanical Systems Engineering, Kookmin University)
Hwang, Sung Ho (Graduate School, Dept. of Mechanics and Design, Kookmin University)
Baek, Doo San (Dept. of Fuel Cell System Development Cell, Hyundai Mobis)
Kim, Tae Young (Fuel Cell Engineering Design Team, Hyundai Motor Company)
Kim, Tae Ho (School of Mechanical Engineering, Kookmin University)
Publication Information
Tribology and Lubricants / v.38, no.5, 2022 , pp. 205-212 More about this Journal
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.
Keywords
High speed motor; Bam foil; Gas foil bearing; Rotordynamics; Bearing clearance;
Citations & Related Records
Times Cited By KSCI : 4  (Citation Analysis)
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