| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To suppress resonance between a cup portion of an impeller and the other vibration source in the state of fastening the cup portion to a rotor holder. <P>SOLUTION: An annular protruded portion is formed at the outer peripheral end of the axial lower end face of a small diameter portion of a boss 34. A through-hole is formed in the center of the boss 34. A shaft 32 is pressed and fixed into the through-hole. A through-hole is formed in the center of a cover portion of the covered cylindrical rotor holder 31 around its rotational axis. The small diameter portion of the boss 34 is fitted to the through-hole. The annular protruded portion is plastically deformed outward in the radial direction. The inner peripheral face of the rotor holder 31 is held between the annular protruded portion plastically deformed outward in the radial direction and the body of the boss 34. A plurality of protruded portions are formed near the upper end of the inner peripheral face of the impeller cup portion 22. The outer peripheral face of the rotor holder 31 is pressed into the inner peripheral ends of the five protruded portions. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
