| 摘要 |
PURPOSE:To reduce high frequency fields which leak in a working space and to obtain the improvement of oscillation efficiency and the lowering of noise by enlarging a diameter of the portion which is not secured to vanes in inner strap rings than that of the portion which is secured to the vanes. CONSTITUTION:In inner strap rings 10, the diameter of the portion which is not secured to vanes 2 is formed larger than that of the portion which is secured to the vanes 2, and in outer strap rings 11, the diameter of the portion which is secured to the vanes 2 is formed larger than that of the portion which is not secured to the vanes 2. Whereby, high frequency fields at the tips 2c of the vanes are approximately equal and the voltage differences are not caused. Thus, high frequency fields which leak in a working space are reduced and it is possible to stably obtain the oscillation. |
