| 摘要 |
PROBLEM TO BE SOLVED: To lower the cost by using components forming a radial dynamic pressure air bearing in common and to prolong the life by suppressing the wear of the surface of the radial dynamic pressure air bearing. SOLUTION: A hollow rotary shaft 41 as a component of the radial dynamic pressure air bearing 40 is formed in a simple shape having uniform outward sizes and then used in common for dynamic air bearing motors of respective types. Further, an axial bearing 49 which supports a rotary body 38 axially is an attraction type magnetic bearing 49 forming a radial magnetic gap between a fixed part 47 and a rotary part 48 arranged inside the hollow rotary shaft 41 and more than a half of the attraction type magnetic bearing 49 axially overlap with the radial dynamic pressure air bearing surface 45, so when the rotary body 38 stops rotating, the radial dynamic pressure air bearing surface 45 of the radial dynamic pressure air bearing 40 comes into linear contact state the wear quantity of the radial dynamic pressure air bearing surface 45 decreases, thereby prolonging the life of the dynamic pressure air bearing motor 33. |
