| 摘要 |
<p>PURPOSE: To correctly position-control a movable wall member by reducing a load caused on the surface of a movable wall member, and by means of simple and inexpensive constitution. CONSTITUTION: A housing 1 is provided which has an annular recess 19 and supporting a movable wall member 5, and an annular inlet passage 4 is divided by the member 5 and an opposite wall 6 of the housing 1. The member 5 can be moved so as to change the width of the passage 4, and airtight seals 20 and 21 are provided between the inner and outer peripheries in the radius directions of the member 5 and the recess 19, and a hole 24 is provided while penetrating the surface of the member 5. This device can reduce all axis directional loads applied to the member 5 by a gas flow passing through the passage 4, thereby reducing the pressure difference between the recess 19 and the passage 4.</p> |
