| 摘要 |
PROBLEM TO BE SOLVED: To provide a bearing device capable of performing finer positioning of a main shaft and realizing high positioning accuracy. SOLUTION: A main thrust bearing part 21 includes a first regulating part 211 for generating a first thrust force with respect to a first face 11a of a main shaft part 1, and a second regulating part 212 for generating a second thrust force with respect to a second face 12a of the main shaft part 1. An adjustable thrust bearing part 4 includes a third opposing face 41b opposed in a non-contact manner to a third face 13a of the main shaft part 1 and generates a changeable adjustable thrust force with respect to the third face 13a. A control part 5 actively changes the adjustable thrust force by moving the third opposing face 41b based on displacement of the main shaft part 1 in the thrust direction. In an equilibrium state, the change amount of the adjustable thrust force of the main shaft part 1 with respect to a predetermined displacement is smaller than a total of the change amount of the first thrust force and the second thrust force with respect to the predetermined displacement. COPYRIGHT: (C)2009,JPO&INPIT
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