| 摘要 |
<p>a precision measuring apparatus (0) defining a measuring interval sealed from environmental influences comprises a shielding housing (10) surrounding a measuring interval and defining within the housing wall a slit (10a) oriented along the measuring interval, a movable member (11) attachable to a measured object and movable along the measuring interval, a carrying member (1a) attached to the movable member (11) and extending through the slit (10a), fluid bearings (12b) interposed between the movable member and the shielding housing to form a bearing gap (12) therebetween and to movably support the movable member (11) on the shielding housing (10) substantially without friction, and sealing fluid (14c) positioned in the bearing gap (12) to seal the slit (10a). The apparatus further includes a fluid supply means (14) for supplying sealing fluid (14c) such as vacuum oil, to the bearing gap (12), and means (18) for evacuating the shielding housing (10). A channel (13b ) for distributing the sealing fluid (14c) from the supply means (14) through the bearing gap (12) is defined by the movable member (11). Channels (13a, 13c) for collecting sealing fluid (14c) in the bearing gap (12) are defined by the wall of the housing (10). The fluid bearings (12b) can be pneumatic, formed by injecting compressed air into the bearing gap (12).</p> |
