| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce thrust load applied to a bearing without complicating a structure in a vacuum pump for exhausting from the atmosphere. <P>SOLUTION: A load assisting structure 12 is provided in order to assist the thrust load applied to a rotor shaft 4 by the difference of the pressure acting. The load assisting structure 12 is equipped with a plate shaped member 13 coaxially fixed with the rotor shaft 4, and annular permanent magnets 14 and 15 fixed on a yoke 16, and a magnetic field is formed by the two annular permanent magnets 14 and 15. The plate shaped member 13 is attracted to the direction of the annular permanent magnets 14 and 15 by the magnetic force acting to the magnetic field formed by the annular permanent magnets 14 and 15. Thus, the attracting force by the load assisting structure 12 is directed to the direction canceling the thrust load, and thereby the load applied to the thrust bearing 11 can be reduced. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
