DYNAMIC BEARING AND SPINDLE DEVICE USING RADIAL DYNAMIC BEARING

PROBLEM TO BE SOLVED: To provide a dynamic bearing and a spindle device capable of reducing vibration even in high speed rotation, and exhibiting enhanced rotation accuracy. SOLUTION: A bearing pad 3 forming the dynamic bearing 1 is a flexible pad having a pad surface 5a capable of advancing and retreating with respect to a mating side surface 20a, and the bearing pad including a flexible pad surface and a fixing part 4 provided between the bearing pads are connected by a continuous surface. In the flexible pad, both ends of a thin part 5 are connected to first and second thin parts 7b and 8b having different length and the fixing part by the connecting surface, and a piezoelectric element 9 is provided on a back surface 5b of a thick part, and pressing force to the thick part is varied, and advancing/retreating is possible. A displacement sensor 12 for measuring displacement with the mating side surface is disposed on the fixing part. Used with a hydrostatic bearing 21a, an elastic deformation amount 33 of the pad surface is increased when a gap 31 is reduced in the dynamic bearing part, and is decreased when the gap is increased, and the load capacity generated on the pad surface is adjusted, and vibration of a spindle is actively restrained. COPYRIGHT: (C)2009,JPO&INPIT