for the stationary helical groove portion 18 and the centrifugal blade portion 20 the first rotor and the second rotor can rotate independently of each other multiple stage rotor blades 27 are provided on the external periphery of the first internal cylinder 26 they are disposed alternately with stator blades 30 provided on the internal periphery of the outer cylinder 10 a stationary helical groove 29 is provided on the internal periphery of the external cylinder 10 which faces the external periphery near the top end of the second internal cylinder 28 stator blades 32 are provided in plural stages under the stationary helical groove 29 on the outer periphery of the second internal cylinder multiple stage centrifugal blades 34 are provided alternately with these stator blades 32 the above mentioned first internal cylinder 26 and second internal cylinder 28 are magnetically floated since they are magnetically floated with a position sensor 36 is provided for detecting axial displacement of the first internal cylinder 26 a radial direction electromagnet 38 is provided for controlling radial direction displacement of the first internal cylinder 26 a position sensor 40 is provided for detecting radial direction displacement of the first internal cylinder 26 an axial direction electromagnet 42 for controlling axial direction displacement of the first internal cylinder 26 a position sensor 44 is provided for detecting axial displacement of the second internal cylinder 28 an axial direction electromagnet 46 is provided for controlling axial direction displacement of the second.