Gas lubrication technology applied in a cryogenic turbo-refrigerator is outlined and discussed on the basis of the investigations of externally-pressurized gas bearing turbo-expander. In particular

the valuable experience to develop several different kinds of external-pressurized gas bearings including double row radial gas supply

double row tangential gas supply

multi-row tangential gas supply is presented and summarized. Moreover

the relationship between gas supply bearing clearance and whirling speed is deduced. The optimal bearing clearance is also obtained. It is found that the optimal bearing clearance will increase by 75% when a common radial feeding-hole bearing is changed to tangential feeding-hole bearing. Correspondingly

the whirling speed can be improved by 30%.