To　verify　the　feasibility　of　substituting　protuberant　foil　bearing　for　traditional　hydrostatic　bearing　in　high　speed　turbomachinery,　both　metallic　protuberant　gas　foil　journal　bearings　and　thrust　bearings　were　applied　to　a　high　speed　turboexpander　with　rotor　diameter　of　25　mm　for　150　m3/h　industrial　oxygen　production.　The　protuberant　gas　foil　journal　bearings　were　circumferentially　staggered　and　the　protuberant　gas　foil　thrust　bearings　were　radially　staggered.　Test　results　indicate　that　the　rotor　is　able　to　operate　stably　under　fully　hydrodynamic　gas-lubricated　protuberant　foil　bearings　to　show　the　favorable　dynamic　property　and　stability.　The　protuberant　foil　bearings　are　quickly　adapted　to　rotor　motion　due　to　the　compliant　elasticity　and　low　inertia.　With　increasing　rotor　speed　the　rotor　orbit　varies　from　irregular　semi-circularity　to　regular　circularity,　and　the　good　repeatability　appears　in　repetitive　tests.　Whirling　motion　of　the　rotor　can　be　suppressed　effectively　to　guarantee　stable　rotor　operation　at　high　speeds.　©　2017,　Editorial　Office　of　Journal　of　Xi＇an　Jiaotong　University.　All　right　reserved.