| 摘要 |
PROBLEM TO BE SOLVED: To enhance load capacity in a radial direction of a fluid dynamic pressure bearing device without increasing in processing cost and rotational torque, thereby to improve rotation accuracy.SOLUTION: In a fluid dynamic pressure bearing device, a ratio of a circumferential width W1 of each inclined hill part G2 of a radial dynamic pressure generation part G to a circumferential width W2 of each inclined groove part G3 thereof, W1/W2, is 1.2 or more, and when the inner diameter of a bearing member is defined as D, the circumferential width W2 of each inclined groove part is 0.2D≤W2≤0.4D.SELECTED DRAWING: Figure 3 |
