A Feasibility Study on the Use of New Gas Foil Bearings in Cryogenic Turboexpander

Experiments have been conducted with two type of gas lubricated foil journal bearings and a small cryogenic turboexpander. One of these bearings is named as a spirally-wound foil bearing and the another is named as a multi-leaves foil bearing. Both of them have much simpler construction and lower cost as compared with the conventional foil bearings. The rotor of cryogenic turboexpander, 103 mm long and weighing 0.9 N, has the working speed up to 230,000 rpm. The main purpose of the investigation is a preliminary examination of stabilizing characteristics of those foil bearings under several different clearances and foil stiffness as well as the durability of the foils. Experimental results indicate the foil bearings presented here offer system stability and high durability, and it confirmed that the application of gas foil bearing to the cryogenic turboexpander is feasible and hopeful.