| 摘要 |
PURPOSE:To shorten axial dimension and obtain a compact bearing device by arranging a magnetic thrust bearing between an axial direction end of a rotary member fitted around a fixed shaft and a housing. CONSTITUTION:An upper end part in axial direction of a fixed shaft 22 is press-fit, glued and fixed into a fixed shaft supporting member 22b of a housing 20. On the peripheral surface of the fixed shaft 22 are arranged radial bearing surfaces 23 and 24 provided with dynamic pressure generating grooves 23a and 24a in herringbone shape. Further, around the lower end is rotatably fitted a hollow-shaped rotary member 32 supported with a magnetic thrust bearing. As a thrust receiving surface 44 side of a thrust receiver 40 on the rotary member 32 side is magnetized to the N pole and a thrust bearing surface 46 side of a thrust bearing 45 on the housing 20 side is also magnetized to the N pole, the thrust bearing supports the rotary member in a levitated condition by means of magnetic repulsive force.
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