| 摘要 |
<p>An optical rotary encoder is provided using a fluid bearing (6,7), which is space-saving, holds down costs for the high-precision processing of components, and has excellent maintainability. A rotary disk (10) is fixed to a disk holder (5) and is accommodated in a cylindrical case (20) together with a fluid bearing mechanism (6,7) and an optical detection unit (4). The optical detection unit (4) and the fluid bearing mechanism (6,7) provide a static system with the cylindrical case (20), which maintains a stationary state even if a rotary shaft (1) is rotated, and are mounted on static system mounting portions (2,3) with the cylindrical case (20). The disk holder (5) and the rotary disk (10) are fitted on the rotary shaft (1). Compressed air is sprayed onto both sides of the rotary disk (10) through a compressed air flow path (6) and a compressed air nozzle (7), to thereby restrict displacement of the disk (10) in a direction parallel to the rotary shaft (1). The compressed air is also sprayed through the compressed air flow path (6) onto the outer circumference of the disk holder (5), to thereby restrict displacement of the disk (10) in a direction perpendicular to the rotary shaft (1). As an alternative to air, it is also possible to use helium or oil as fluid in the fluid bearing (6,7). <IMAGE></p> |
