| 摘要 |
PURPOSE:To reduce vibration during rotation and bearing damage at the time of starting stop by making the support position of the hollow rotary body of a thrust magnetic bearing coincide with a balance point where pressure moments generated by a radial pneumatic bearing in a direction vertical to a fixed shaft to support the hollow rotary body become equal. CONSTITUTION:Herringbonelike dynamic pressure generation grooves 5a, 5b are provided at the upper and lower sides of the surface of a fixed shaft 2, and a radial pneumatic bearing is formed. A thrust magnetic bearing is composed of a ringlike magnetic bearing rotary side magnet 8 fixed at hollow rotary body 4 and a magnetic bearing fixed side magnet 9 arranged around the magnet 8 and fixed at a housing 3. The support position of the hollow rotary body 4 by means of the magnetic bearings 8, 9 is made coincide with a balance point P where pressure moments generated by the pneumatic bearing in a direction vertical to the fixed shaft 2 to support the hollow rotary body 4 become equal. As result, the radial effect of the magnetic bearing acts upon the pneumatic bearing equally, and vibration during rotation and damage given to the bearings at the time of starting stop can be reduced. |
