PURPOSE: To prevent the occurrence of scuffing even at the time of overload, by providing a bearing supporting part, exhaust nozzles opened in the inner peripheral surface of a bearing supporting part, and air holes supplying pressure gas to the exhaust nozzles, via a gap in the outer periphery of a bearing part in a static pressure gas bearing for a high-speed rotation spindle, etc.
CONSTITUTION: A bearing supporting part 2 having a cylindrical hollow part is fixed to the inner side of a casing 1; and a hollow and cylindrical bearing part 4 is located, so that the outer peripheral surface can form a gap in an interval with the inner peripheral surface of the bearing supporting part 2, in the cylindrical hollow part. A gap is interposed between the inner peripheral surface of the bearing part 4 and the outer peripheral surface of a rotating shaft 3. An air reservoir 11, communicated with an air supplying hole 12, is formed on the inner peripheral surface of a casing 1 opposite to the bearing supporting part 2. Air holes 21 and 22, communicated with the air reservoir 11, are provided on the bearing supporting part 2, and also exhaust nozzles 23 and 24 are formed on a position opposite to the bearing part 4, communicating between the air holes 21 and 22 and the exhaust nozzles 23 and 24. A contact detector 5 is provided between the bearing supporting part 2 and the bearing part 4, and a driving source is stopped when the supporting part 2 is contacted with the bearing part 4.
YAHARA HARUKI
HINO KAZUNORI
ISHII HIDEJI
