| 摘要 |
<P>PROBLEM TO BE SOLVED: To hold high-density magnets during high-speed rotation in a multistage centrifugal compressor that is including a built-in high-speed motor. <P>SOLUTION: The multistage centrifugal compressor is constituted to include (a) a variable-speed permanent magnet motor, having an electrically commutated stator coil surrounding a rotor with permanent magnets, and (b) a plurality of impellers which rotate with a rotor shaft, wherein the rotor has the magnetic steel rotor shaft 75 rotatably supported by a bearing. (c) The rotor includes (1) the magnetic steel rotor shaft 75, (2) the permanent magnets 72a, and (3) a plastic bonding portion 72b reinforced by a prestressed carbon graphite fiber for holding the permanent magnets 72a to the shaft, wherein the rotor shaft has a square cross section, formed by four surfaces parallel to the rotating axial center of the shaft; and the permanent magnets are formed by cylindrical faces and flat faces and have circular partial cross sections fixed to each of the four surfaces of the square steel shaft, and these permanent magnets are arranged so that their polarities alternate with each other. <P>COPYRIGHT: (C)2008,JPO&INPIT |
