| 摘要 |
<P>PROBLEM TO BE SOLVED: To meet requirements for increasing speed, extending service life, and preventing fouling caused by oil of an apparatus by preventing external outflow of oil in a bearing part, deterioration of oil, and degradation of bearing rigidity in a motor equipped with a hydrodynamic bearing device. <P>SOLUTION: Oil sump stepped parts are arranged in both ends of herringbone grooves in two places of a hydrodynamic bearing. A spiral groove for force-feeding oil is arranged in the vicinity of a bearing opening end outlet. When the pattern width of the herringbone groove is (a), (b), (c) and (d), the pattern width of the spiral groove is (e), and the length of the oil sump stepped part is (p), (q), (r) and (s) in order from an upper side, b-a>0, d-c>0, e≥(b-a)+(d-c)>0, p≥e-(b-a)-(d-c)>0, q≥p, r≥e-(b-a)-(d-c)>0, and s≥r are set. This setting prevents the outflow of oil from the bearing end and the entrainment of external air. <P>COPYRIGHT: (C)2007,JPO&INPIT |
