| 摘要 |
PROBLEM TO BE SOLVED: To prevent shaft from floating due to cylindricity worsening of a sleeve of a dynamic bearing device. SOLUTION: The sleeve 2 of the dynamic bearing device generates a dynamic pressure on an oil 6 charged between shaft 1 with dynamic pressure generating groove 7a, 7b of herring bone shapes. Assembling a disc 3 supporting a thrust plate 4 at an lower end of the sleeve 2 by caulking thereof worsens the cylindricity by widening of the lower end of the sleeve 2 to float the shaft 1, and a transporting force feeding the oil 6 upwards is generated by sliding turn-rounds A, B of the dynamic generating grooves 7a, 7b of herring bone shape so as to cancel this imbalance of a dynamic pressure. |
