小型ターボブロア用フォイル式空気軸受の開発および性能検証

抄録

Gas foil bearings (GFBs) are expected to be used in a variety of turbomachinery such as turbocharger, compressor, air cycle machine. One of the main issues for implementing the GFB to the turbomachinery is wear due to rubbing between shaft and bearing. In order to reduce wear, it is important to precisely predict and lower the speed of lift-off. This paper presents measurement by the test rig for the evaluation of the lift-off speed. During the lift-off test, the drag torque of the GFB was measured and the lift-off was detected by its value. The static load applied to the GFB was varied from 2 N to 5.2 N and the influence of the load on the lift-off speed was estimated. The predicted lift-off speed corresponded with the measured value. It was found that pre-load of GFB is the main factor to determine the lift-off speed in the low static load condition, and contrary to the expectations, static load has little influence one the test results. Finally, this paper proposes the way to lower the lift-off speed.