CFD Analysis of Hydroinertia Gas Journal Bearings for Ultra-high Speed Rotary Machines (Effect of Shaft Eccentricity on the Load Capacity)

10.6567/IFToMM.14TH.WC.PS18.001

Tomohiko Ise；Keisuke Teramae；Toshihiko Asami

externally pressurized gas bearing ； hydroinertia bearing ； rotary machines ； load capacity ； negative pressure

Proceedings of the 14th IFToMM World Congress

14th-6（2015 / 11 / 11）

152 - 156

英文

Hydroinertia gas journal bearings have been applied to solid state nuclear magnetic resonance spectroscopy. These bearings, which require a larger radial clearance than conventional externally pressurized bearings, achieve stable operation for ultra high-speed rotation of spinner shaft at several million rpm. However, their small diameters, which range within 1-6 mm, have limited experimental verifications of their static characteristics. A computational fluid dynamics analysis was therefore performed to fill this gap. The effects of radial clearance and eccentricity ratio on bearing characteristics, such as pres- sure distribution and load capacity, were investigated. In this report, shift of the characteristics from conventional bearings to the hydroinertia bearings was clarified in terms of eccentricity ratio. This analysis showed that negative and positive pressures generated some eccentricity ratio. Pressure distribution also changes in the bearing eccentricity ratio. A large load capacity was obtained at hydroinertia bearing.